[Federal Register Volume 80, Number 190 (Thursday, October 1, 2015)]
[Rules and Regulations]
[Pages 59424-59497]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2015-24443]
[[Page 59423]]
Vol. 80
Thursday,
No. 190
October 1, 2015
Part IV
Department of the Interior
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Fish and Wildlife Service
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50 CFR Part 17
Endangered and Threatened Wildlife and Plants; Endangered Status for 16
Species and Threatened Status for 7 Species in Micronesia; Final Rule
Federal Register / Vol. 80 , No. 190 / Thursday, October 1, 2015 /
Rules and Regulations
[[Page 59424]]
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DEPARTMENT OF THE INTERIOR
Fish and Wildlife Service
50 CFR Part 17
[Docket No. FWS-R1-ES-2014-0038; 4500030113]
RIN 1018-BA13
Endangered and Threatened Wildlife and Plants; Endangered Status
for 16 Species and Threatened Status for 7 Species in Micronesia
AGENCY: Fish and Wildlife Service, Interior.
ACTION: Final rule.
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SUMMARY: We, the U.S. Fish and Wildlife Service, determine endangered
status under the Endangered Species Act of 1973, as amended, for 16
plant and animal species from the Mariana Islands (the U.S. Territory
of Guam and the U.S. Commonwealth of the Northern Mariana Islands). We
also determine threatened status for seven plant species from the
Mariana Islands and greater Micronesia in the U.S. Territory of Guam,
the U.S. Commonwealth of the Northern Mariana Islands, the Republic of
Palau, and the Federated States of Micronesia (Yap). The effect of this
regulation will be to add these 23 species to the Federal Lists of
Endangered and Threatened Wildlife and Plants.
DATES: This rule becomes effective November 2, 2015.
ADDRESSES: This final rule is available on the Internet at http://www.regulations.gov and http://www.fws.gov/pacificislands. Comments and
materials we received, as well as some of the supporting documentation
used in preparing this final rule, are available for public inspection
at http://www.regulations.gov. All of the comments, materials, and
documentation that we considered in this rulemaking are available, by
appointment, during normal business hours, at: U.S. Fish and Wildlife
Service, Pacific Islands Fish and Wildlife Office, 300 Ala Moana
Boulevard, Room 3-122, Honolulu, HI 96850; by telephone at 808-792-
9400; or by facsimile at 808-792-9581.
FOR FURTHER INFORMATION CONTACT: Kristi Young, Acting Field Supervisor,
U.S. Fish and Wildlife Service, Pacific Islands Fish and Wildlife
Office, 300 Ala Moana Boulevard, Room 3-122, Honolulu, HI 96850; by
telephone at 808-792-9400; or by facsimile at 808-792-9581. Persons who
use a telecommunications device for the deaf (TDD) may call the Federal
Information Relay Service (FIRS) at 800-877-8339.
SUPPLEMENTARY INFORMATION:
Executive Summary
Why we need to publish a rule. Under the Endangered Species Act of
1973, as amended (Act or ESA), a species may warrant protection through
listing if it is endangered or threatened throughout all or a
significant portion of its range. Listing a species as an endangered or
threatened species can only be completed by issuing a rule. Critical
habitat shall be designated, to the maximum extent prudent and
determinable, for any species determined to be an endangered or
threatened species under the Act.
This rule will finalize the listing of 23 species from the Mariana
Islands as endangered or threatened species, one of which (Cycas
micronesica) also occurs in the Republic of Palau and the Federated
States of Micronesia (Yap). For the sake of brevity, throughout this
document we refer to these 23 species simply as the 23 Mariana Islands
species. Sixteen of these species are listed as endangered species:
Seven plants--Eugenia bryanii (no common name (NCN)), Hedyotis
megalantha (pau dedu, pao doodu), Heritiera longipetiolata (ufa
halumtanu, ufa halom tano), Phyllanthus saffordii (NCN), Psychotria
malaspinae (aplokating palaoan), Solanum guamense (Biringenas
halumtanu, birengenas halom tano), and Tinospora homosepala (NCN); and
nine animals--the Pacific sheath-tailed bat (Mariana subspecies,
Emballonura semicaudata rotensis; payeyi, paischeey), Slevin's skink
(Emoia slevini; gualiik halumtanu, gholuuf), Mariana eight-spot
butterfly (Hypolimnas octocula marianensis; ababbang, libweibwogh),
Mariana wandering butterfly (Vagrans egistina; ababbang, libweibwogh),
Rota blue damselfly (Ischnura luta; dulalas Luta, dulalas Luuta),
fragile tree snail (Samoana fragilis; akaleha dogas, denden), Guam tree
snail (Partula radiolata; akaleha, denden), humped tree snail (Partula
gibba; akaleha, denden), and Langford's tree snail (Partula langfordi;
akaleha, denden). Seven plant species--Bulbophyllum guamense (siboyas
halumtanu, siboyan halom tano), Dendrobium guamense (no common name
(NCN), Cycas micronesica (fadang, faadang), Maesa walkeri (NCN),
Nervilia jacksoniae (NCN), Tabernaemontana rotensis (NCN), and
Tuberolabium guamense (NCN)--are listed as threatened species.
Delineation of critical habitat requires, within the geographical
area occupied by the species, identification of the physical or
biological features essential to the species' conservation. Information
regarding the life functions and habitats associated with these life
functions is complex, and informative data are largely lacking for the
23 Mariana Islands species. A careful assessment of the areas that may
have the physical or biological features essential for the conservation
of the species and that may require special management considerations
or protections, and thus qualify for designation as critical habitat,
will require a thorough assessment. We require additional time to
analyze the best available scientific data in order to identify
specific areas appropriate for critical habitat designation.
Accordingly, we find designation of critical habitat to be ``not
determinable'' at this time.
The basis for our action. Under the Endangered Species Act, we can
determine that a species is an endangered or threatened species based
on any of five factors: (A) The present or threatened destruction,
modification, or curtailment of its habitat or range; (B)
Overutilization for commercial, recreational, scientific, or
educational purposes; (C) Disease or predation; (D) The inadequacy of
existing regulatory mechanisms; or (E) Other natural or manmade factors
affecting its continued existence. We have determined that the 23
Mariana Islands species are experiencing population-level impacts as
the result of the following current and ongoing threats:
Habitat loss and degradation due to development, military
activities, and urbanization; nonnative feral ungulates (hoofed
mammals, for example, deer, pigs, and water buffalo) and nonnative
plants; rats; snakes; wildfire; typhoons; water extraction; and the
synergistic effects of future climate change.
Predation or herbivory by nonnative feral ungulates, rats,
snakes, monitor lizards, slugs, flatworms, ants, and wasps.
The inadequacy of existing regulatory mechanisms to
prevent the introduction and spread of nonnative plants and animals.
Direct impacts from ordnance and live-fire from military
training, recreational vehicles, and exacerbated vulnerability to
threats and, consequently, extinction, due to small numbers of
individuals and populations.
Peer review and public comment. We sought comments from independent
specialists to ensure that all of our determinations are based on
scientifically sound data, assumptions, and analyses. We also
considered all
[[Page 59425]]
comments and information received during the comment periods and public
hearings.
Previous Federal Actions
Please refer to the proposed listing rule, published in the Federal
Register on October 1, 2014 (79 FR 59364), for previous Federal actions
for these species prior to that date. The publication of the proposed
listing rule opened a 60-day comment period, beginning on October 1,
2014, and closing on December 1, 2014. In addition, we published a
public notice of the proposed rule on October 18, 2014, in the Marianas
Variety, Marianas Variety Guam, and the Guam Pacific Daily News
newspapers. On January 12, 2015 (80 FR 1491), we reopened the comment
period for an additional 30 days and announced two public hearings,
each preceded by public information meetings (January 27, 2015, on
Guam; and January 28, 2015, on Saipan); and two separate public
information meetings, one each on Rota (January 29, 2015) and Tinian
(January 31, 2015). This second comment period closed on February 11,
2015. We published public notices in the local Marianas Variety and
Pacific Daily News on January 23, 2015, in order to inform the public
about the hearings and information meetings, as well as the reopening
of the comment period. In total, we accepted public comments on the
October 1, 2014, proposed rule (79 FR 59364) for 90 days.
Summary of Changes From Proposed Rule
In preparing this final rule, we reviewed and fully considered
comments from the peer reviewers and public on the proposed listings
for 23 species. This final rule incorporates the following substantive
changes to our proposed rule, based on the comments we received:
(1) The proposed rule described the status of five plant species
(four orchids: Bulbophyllum guamense, Dendrobium guamense, Nervilia
jacksoniae, and Tuberolabium guamense; and a plant in the family
Primulaceae, Maesa walkeri) as meeting the definition of an endangered
species under section 3(6) of the Act (any species which is in danger
of extinction throughout all or a significant portion of its range).
However, new information from further surveys has shown that these five
plant species are more numerous on the island of Rota than previous
data indicated, each with a population structure consisting of
seedlings, juveniles, and adults. This new information indicates that
these five plant species are not quite as imperiled throughout their
ranges as previously understood at the time of the proposed rule.
However, these species are still susceptible to habitat destruction and
modification by nonnative plants and animals, fire, and the future
effects of climate change on Rota. Additionally, at least 50 percent of
their respective ranges occur on the island of Guam, where these
species once occurred in abundance but now exist in very low numbers of
individuals, and face similar threats as on Rota, in addition to
habitat destruction and modification by urban development, military
development and training, brown treesnakes (Boiga irregularis), and
feral pigs (Sus scrofa).
The Act defines an endangered species as ``any species which is in
danger of extinction throughout all or a significant portion of its
range,'' and a threatened species as ``any species which is likely to
become an endangered species within the foreseeable future throughout
all or a significant portion of its range.'' Therefore, because the
four orchid species (Bulbophyllum guamense, Dendrobium guamense,
Nervilia jacksoniae, and Tuberolabium guamense) and Maesa walkeri
appear relatively healthy on Rota, but face threats throughout all of
their ranges, and have declined across at least 50 percent of their
ranges (i.e., on Guam), we have retained them in this final listing
determination but have changed their status to threatened species, as
they are at risk of becoming endangered within the foreseeable future
throughout all of their ranges. All new data received during the
comment period for these five species have been added to Description of
the 23 Mariana Islands Species and Summary of Biological Status and
Threats Affecting the 23 Mariana Islands Species, below. Further, our
rationale for listing each of these five species as threatened species,
versus endangered species, is discussed under Determination, below.
(2) We updated the section titled ``Historical and Ongoing Human
Impacts'' under The Mariana Islands, below, to include recent changes
in proposed military actions.
(3) We have corrected our original description of the political
division of Micronesia. See ``Political Division'' under The Mariana
Islands, below.
(4) We have added new island occurrences for three species
addressed in this final rule. Dendrobium guamense was recently
discovered on the island of Aguiguan--a brand new island record
(Zarones 2015a, in litt.); the humped tree snail was recently observed
on Tinian, an island on which the humped tree snail was previously
thought to be extirpated (Naval Facilities Engineering Command Pacific
(NavFac, Pacific) 2014, pp. 5-5, 5-7); and one individual of Heritiera
longipetiolata was reported from Rota, an island on which it was
thought this species was extirpated (Cook 2010, pers. comm. cited in
CNMI Department of Land and Natural Resources (DLNR) 2014, in litt.).
These three island additions have been placed under Islands in the
Mariana Archipelago, Description of the 23 Mariana Islands Species, and
Table 1, below.
(5) We have corrected the common names for many of the plant and
animal species addressed in this final rule after consultation with a
Chamorro and Carolinian language expert and a comment received from a
peer reviewer. These changes can be observed in Table 1 and under
Description of the 23 Mariana Islands Species, below.
(6) We have added the parenthetical ``(Mariana subspecies)'' to the
common name of the Pacific sheath-tailed bat addressed in this rule,
specifically the subspecies Emballonura semicaudata rotensis, to allow
the reader to more easily distinguish between the four subspecies of
Pacific sheath-tailed bats that are known by the same common name.
(7) Due to a comment we received from a peer reviewer, we have
changed our general description of partulid (referring to a genus of
tree snails in the Pacific) characteristics (see Description of the 23
Mariana Islands Species) to include that the mobility of partulids is
more related to ambient precipitation and humidity, rather than with
the time of day. Previous reports indicated that partulids are
primarily nocturnal.
(8) Due to comments received from a peer reviewer and new
information, we have expanded our description of the negative impacts
associated with the manokwari flatworm, also known as the New Guinea
flatworm (Platydemus manokwari), on the four tree snails under Flatworm
Predation on Tree Snails under Summary of Biological Status and Threats
Affecting the 23 Mariana Islands Species, below. This new information
suggests that we had greatly underestimated the severity and scope of
the threat posed by the manokwari flatworm in the proposed rule.
(9) Due to comments received by the U.S. Navy, and in light of the
new 2014 Draft Supplemental Environmental Impact Statement (SEIS) and
subsequent 2015 Final EIS, we updated the description of the Marine
Corps relocation under ``Historical and Ongoing Human Impacts,'' below.
We
[[Page 59426]]
cited the Final Supplemental EIS (SEIS) released in July of 2015, and
associated changes, which include a proposal to construct and operate
facilities on Guam (not Tinian) to support the training and operations
of Marines and the removal of the proposal to create four ranges on
Tinian since the associated training requirements satisfied by those
four ranges are now the subject of another EIS (Commonwealth of the
Northern Mariana Islands Joint Military Training (CJMT) EIS, described
below). We also dropped ``and Tinian'' in the description of the
revised proposed actions associated with the 2015 Final SEIS associated
with the relocation. Additionally, we removed the construction of a
deep-draft wharf in Apra Harbor and facilities to support the U.S.
Missile Defense Task Force since this is no longer proposed on Guam
(and is not addressed in the revised proposed action covered in the
2014 Draft SEIS or 2015 Final SEIS).
(10) Due to comments received by the U.S. Navy, and in light of the
new 2015 Final SEIS, we updated the description of the Marine Corps
relocation under ``Historical and Ongoing Human Impacts,'' below. The
updates include the construction of a Marine Corps cantonment (main
base) at Naval Computer and Telecommunications Station Finegayan,
family housing on Andersen Air Force Base (AAFB), and a live-fire
training range on AAFB-Northwest Field as the preferred alternatives.
We noted that Orote Point, Pati Point, and Navy Barrigada are no longer
preferred locations for any facilities to support the Marine Corps
move.
(11) We have edited the section titled ``Ordnance and Live-Fire
Training'' under Factor E. Other Natural or Manmade Factors Affecting
Their Continued Existence, below. We changed the physical location of
the ordnance and live-fire training, and subsequently the species
impacted by this threat, due to changes presented in the Navy's 2014
Draft SEIS (Joint Guam Program Office (JGPO)-NavFac, Pacific 2014, p.
ES-1) and 2015 Final SEIS (JGPO-NavFac, Pacific 2015, p. ES-11; http://www.guambuildupeis.us/), and the 2015 CNMI Joint Military Training
Draft EIS/Overseas EIS (OEIS) (http://www.cnmijointmilitarytrainingeis.com/about). In this final rule, the
species that are considered to be negatively impacted by ordnance and
live-fire include the plants Cycas micronesica, Heritiera
longipetiolata, Psychotria malaspinae, and Tabernaemontana rotensis and
the humped tree snail, Mariana eight-spot butterfly, and Slevin's
skink. This change is also noted under ``Historical and Ongoing Human
Impacts'' and Table 3, below.
(12) We added new information to ``Conservation Efforts to Reduce
Disease and Predation'' and ``Conservation Efforts to Reduce Habitat
Destruction, Modification, or Curtailment of Its Range,'' below. In
2013, the U.S. Navy erected five new exclosures on Tinian, each with
1,000 mature individuals of Cycas micronesica. In 2014, the U.S. Navy
funded $5.1 M towards brown treesnake projects in the Mariana Islands.
(13) Due to new data we received during the comment period, we
added the Mariana eight-spot butterfly, Mariana wandering butterfly,
and the Pacific sheath-tailed bat (Mariana subspecies) to ``Small
Number of Individuals and Populations,'' below. A recent genetic
analysis found no heterogeneity exists between three separate
populations of the Mariana eight-spot butterfly on Guam (Lindstrom and
Benedict 2014, p. 27). In fact, they found the genetic sequences
studied to be identical, which is indicative that little population
structure exists among these mobile insects, and that they have
recently experienced a population bottleneck limiting genetic diversity
for this species on Guam (Lindstrom and Benedict 2014, p. 27).
Additionally, since there are no recent observations of the Mariana
wandering butterfly, we have deduced that if a population exists, it
does so in very small numbers and, therefore, faces the same threat of
reduced genetic diversity as the Mariana eight-spot butterfly. A recent
genetic analysis of the Pacific sheath-tailed bat (Mariana subspecies)
found no genetic diversity among the only known extant population of
this species (Oyler-McCance et al. 2013, pp. 1,034-1,035). This new
data, combined with the observed decrease in range from five islands
formerly (Guam, Rota, Saipan, Tinian, and Aguiguan) to just one at
present (Aguiguan), has led the Service to conclude that the Pacific
sheath-tailed bat (Mariana subspecies) is at risk from low numbers of
individuals and populations. We have added the two butterflies and bat
addressed in this rule to the threat of small number of individuals and
populations under Table 3, and Factor E. Other Natural or Manmade
Factors Affecting Their Continued Existence ``Small Number of
Individuals and Populations,'' below. Additionally, we added the
fragile tree snail under the section titled ``Small Number of
Individuals and Populations,'' below, as it was noted in Table 3, but
missing from the discussion under Factor E.
(14) Due to a comment from a peer reviewer, we have made a change
regarding the life-cycle of Slevin's skink under Description of the 23
Mariana Islands Species, below. In the proposed rule, we cited Brown
(1991, pp. 14-15) as stating that Slevin's skinks are viviparous (lay
their eggs internally and give birth to live young). We have corrected
this statement to reflect more recent observations indicating that
Slevin's skinks are oviparous (lay eggs that mature and hatch
externally) (Zug 2013, p. 184; Rodda 2014, in litt.).
(15) Due to new information received during the comment period, we
have added a new occurrence for the Rota blue damselfly. Zarones (et
al. 2015b, in litt.) reported a new observation of an individual of the
Rota blue damselfly, located at a stream east of the Water Cave that is
not connected to the Water Cave (Okgok) Stream. This finding was
confirmed by U.S. Fish and Wildlife Service (Service) entomologists.
This new occurrence has been added under Description of the 23 Mariana
Islands Species, below.
(16) According to new information we received during the comment
period, we corrected the name of I-Chenchon Park, which is now the
Mariana Crow Conservation Area; added the Sabana Heights and Talakhaya
conservation areas under the Sabana Wildlife Conservation Area on Rota;
and added the newly established Nightingale Reed-warbler Conservation
Area and the Micronesian Megapode Conservation area to conservation
areas on Saipan (see Islands in the Mariana Archipelago, below).
(17) After further analysis, we have concluded that feral cattle
are not a threat to the plant Heritiera longipetiolata on the island of
Tinian, nor are feral cattle considered present in large enough numbers
to be assigned to the island of Tinian in Table 4, below. The humped
tree snail was believed to be extirpated from Tinian at the time of the
proposed rule and, therefore, was not previously assigned this threat
on Tinian. Both feral and domestic cattle have been present on Tinian
for centuries and have reportedly caused broad-ranging negative impacts
to the forest ecosystem (i.e., erosion, trampling, and grazing);
however, the number of feral cattle on Tinian has declined in recent
times (Wiles et al. 1990, pp. 167-180; Flores 2015, in litt.). Cattle
ranching on Tinian is on the rise, and depending on the location and
amount of land allotted to cattle ranching, negative impacts to the
forest ecosystem may be observed in the future. However, at the time of
this final rule, neither feral nor domestic cattle
[[Page 59427]]
are considered a threat to the plant Heritiera longipetiolata or the
humped tree snail on the island of Tinian.
(18) In the Regulation Promulgation section of the proposed rule,
we identified the historic range of Cycas micronesica as Guam and the
Mariana Islands. We have corrected the historic range of Cycas
micronesica in this final rule to additionally include the sovereign
island nation of the Federated States of Micronesia (the island of
Yap), and the independent island nation of the Republic of Palau.
Background
Mariana Islands Species Addressed in This Final Rule
Table 1 below provides the scientific name, common name, listing
status, and range (islands on which the species is found) for the 23
Mariana Islands species that are the subjects of this final rule.
Following the table, Figure 1 provides a map of the islands that
comprise the Mariana archipelago.
Table 1--The 23 Mariana Islands Species Addressed in This Final Rule
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Scientific name Common name(s) Listing status Range
----------------------------------------------------------------------------------------------------------------
Plants
Bulbophyllum guamense.............. wild onion siboyas Threatened........... Guam, Rota, Saipan (H),
halumtanu \Ch\, siboyan Pagan (H).
halom tano \CI\.
Cycas micronesica.................. fadang \Ch\, faadang Threatened........... Guam, Rota, Pagan
\CI\. [Dagger], Palau *, Yap.*
Dendrobium guamense................ NCN..................... Threatened........... Guam, Rota, Saipan (H),
Tinian, Aguiguan, Agrihan
(H).
Eugenia bryanii.................... NCN..................... Endangered........... Guam.
Hedyotis megalantha................ pao dedu \Ch\, pao doodu Endangered........... Guam.
\CI\.
Heritiera longipetiolata........... ufa halumtanu \Ch\, ufa Endangered........... Guam, Saipan, Tinian,
halom tano \CI\. Rota.
Maesa walkeri...................... NCN..................... Threatened........... Guam, Rota.
Nervilia jacksoniae................ NCN..................... Threatened........... Guam, Rota.
Phyllanthus saffordii.............. NCN..................... Endangered........... Guam.
Psychotria malaspinae.............. aplokating palaoan Ch / Endangered........... Guam.
CI.
Solanum guamense................... Biringenas halumtanu Endangered........... Guam, Rota (H), Saipan
\Ch\, birengenas halom (H), Tinian (H), Asuncion
tano \CI\. (H), Guguan (H), Maug
(H).
Tabernaemontana rotensis........... NCN..................... Threatened........... Guam, Rota.
Tinospora homosepala............... NCN..................... Endangered........... Guam.
Tuberolabium guamense.............. NCN..................... Threatened........... Guam, Rota, Tinian (H),
Aguiguan (H).
Animals
Emballonura semicaudata rotensis... Pacific sheath-tailed Endangered........... Aguiguan, Guam (H), Rota
bat (Mariana (H), Tinian (H), Saipan
subspecies), payeyi (H), Anatahan (H ),
\Ch\, paischeey \CI\. Maug (H ).
Emoia slevini...................... Slevin's skink, Marianas Endangered........... Guam (H), Cocos Island,
Emoia, Marianas skink, Rota (H), Tinian (H),
gualiik halumtanu \Ch\, Aguiguan (H), Sarigan,
gholuuf \CI\. Guguan, Pagan, Alamagan,
Asuncion.
Hypolimnas octocula marianensis.... Mariana eight-spot Endangered........... Guam, Saipan (H).
butterfly, ababbang
\Ch\, Libweibwogh \CI\.
Vagrans egistina................... Mariana wandering Endangered........... Rota, Guam (H).
butterfly, ababbang
\Ch\, Libweibwogh \CI\.
Ischnura luta...................... Rota blue damselfly, Endangered........... Rota.
dulalas Luta \Ch\,
dulalas Luuta \CI\.
Partula gibba...................... humped tree snail, Endangered........... Guam, Rota, Aguiguan,
akaleha \Ch\, denden Alamagan, Pagan, Sarigan,
\CI\. Saipan, Tinian, Anatahan
(H).
Partula langfordi.................. Langford's tree snail, Endangered........... Aguiguan.
akaleha \Ch\, denden
\CI\.
Partula radiolata.................. Guam tree snail, akaleha Endangered........... Guam.
\Ch\, denden \CI\.
Samoana fragilis................... fragile tree snail, Endangered........... Guam, Rota.
akaleha dogas \Ch\,
denden \CI\.
----------------------------------------------------------------------------------------------------------------
NCN = no common name.
(H) = historical occurrence (20 years or more prior to present date).
(H Sec. ) = possible historical occurrence.
Ch = Chamorro name.
CI = Carolinian name.
* = range outside of the Mariana Islands.
[Dagger] = Tentative occurrence.
Translations courtesy of the Chamorro/Carolinian Language Policy Commission.
Bold type in the Listing Status and Range columns indicates a change in range from the proposed rule.
BILLING CODE 4310-55-P
[[Page 59428]]
[GRAPHIC] [TIFF OMITTED] TR01OC15.080
BILLING CODE 4310-55-C
The Mariana Islands
Here we discuss only background information pertinent to the
Mariana Islands that has changed since the proposed rule. Please see
the proposed rule (79 FR 59364; October 1, 2014) for a description of
the general geography, geology, vegetation, hydrology, climate,
biogeography, and pre-historic human impact. We would like to
acknowledge a spelling error in the proposed rule under ``Hydrology,''
where we incorrectly spelled Talofofo as Tolofofo. Talofofo is the
correct spelling for this hydrological region in Guam. Additionally, we
have made substantial changes from the proposed rule to the
[[Page 59429]]
below section, Historical and Ongoing Human Impacts, for the reasons
described above in the section Summary of Changes from Proposed Rule.
Historical and Ongoing Human Impacts
After the initial Chamorro modifications for agriculture and
villages, the flora and fauna on the Mariana Islands continued to
undergo alterations due not only to ongoing volcanic activity in the
northern islands, but also to land use activities and nonnative species
introduced by European colonialists. The arrival of the Spanish in 1591
further imposed degradation of the ecosystems of the Mariana Islands
with the introduction of numerous nonnative animals and plants. The
Spanish occupied the Mariana Islands for nearly 300 years (SIO 2014, in
litt.). In 1899, Spain sold the Mariana Islands to Germany, with the
exception of Guam, which was ceded to the United States as a result of
the Spanish-American war (SIO 2012, in litt.; Encyclopedia Britannica
2014, in litt.).
The German administration altered the forest ecosystem on Rota,
Saipan, and Tinian, and on some of the northern islands, by means of
Cocos nucifera (coconut) farming, which was encouraged for the
production of copra (the dried fleshy part of a coconut used to make
coconut oil) (Russell 1998, pp. 94-95). Upon the start of World War I,
the Japanese quickly took over German occupied islands and accelerated
the alteration of the landscape by clearing large areas of native
forest on Rota, Saipan, and Tinian, for growing Saccharum officinarum
(sugarcane) and building associated refineries, and for planting Acacia
confusa (sosugi) to provide fuel wood (CNMI-SWARS 2010, pp. 6-7). The
Japanese drastically altered the islands of Saipan and Tinian, and to a
lesser extent on Rota, leaving little native forest. Military
activities during World War II further altered the landscape on Saipan
and Tinian. Rota was a notable exception, left relatively untouched
(CNMI-SWARS 2010, p. 7). Japan also occupied Guam at the onset of World
War II; however, by 1944 the United States neutralized the Mariana
Islands with the recapture of Saipan, Tinian, and Guam (Encyclopedia
Britannica 2014, in litt.). Since World War II, the U.S. military has
developed a strong presence in the Mariana Islands, particularly on the
island of Guam, where both the U.S. Navy and U.S. Air Force operate
large military installations. The island of Farallon de Medinilla is
used for military ordnance training (Berger et al. 2005, p. 130).
Currently, the U.S. Department of Defense is implementing a project
referred to as the ``Guam and Commonwealth of the Northern Mariana
Islands Military Relocation'' (Joint Guam Program Office (JGPO)-Naval
Facilities Engineering command, Pacific (JGPO-NavFac, Pacific) 2010a,
p. ES-1; JGPO-NavFac, Pacific 2013, pp. 1-1--1-3; JGPO-NavFac, Pacific
2014, pp. ES-1--ES-34; JGPO-NavFac, Pacific 2015, pp. ES-1--ES-40;
http://guambuildupeis.us/). This military relocation proposes: (1) The
relocation of a portion of the U.S. Marine Corps (Marine Corps)
currently in Okinawa, Japan, which consists of up to 5,000 Marines and
their 1,300 dependents, as revised in the Draft Supplemental
Environmental Impact Statement (SEIS) (JGPO-NavFac, Pacific 2014, p.
ES-3) and Final SEIS (JGPO-NavFac, Pacific 2015, pp. ES-1--ES-40;
http://guambuildupeis.us/); (2) the development of facilities and
infrastructure (i.e., cantonment, family housing, and associated
infrastructure) on Guam to support the relocation of military personnel
and their dependents (JGPO-NavFac, Pacific 2015, p. ES-3; http://guambuildupeis.us/); and (3) the development and construction of
facilities and infrastructure on Guam to support training and
operations for the relocated Marines, specifically a Live-Fire Training
Range Complex (LFTRC) (JGPO-NavFac, Pacific 2015, p. ES-3; http://guambuildupeis.us/)
The Final 2015 SEIS focuses on changes to the proposed actions and
alternatives identified in the 2010 Final EIS (JGPO-NavFac, Pacific
2014, p. ES-1) and 2014 Draft SEIS (JGPO-NavFac, Pacific 2015, pp. ES-
1--ES-40; http://guambuildupeis.us/). The preferred alternative sites
on Guam for the implementation of the Marine relocation efforts and
development of an LFTRC now include Alternative E Finegayan (Navy Base
Guam)-Andersen Air Force Base (AFB) and Alternative 5 Northwest Field
on Andersen AFB, respectively. Alternative E is a new alternative not
presented in the 2014 Draft SEIS. The 2014 Draft SEIS had listed
Alternative A Finegayan as the preferred alternative for cantonment and
housing, and the new preferred Alternative E places the cantonment on
Finegayan and family housing on Andersen AFB. This new Alternative E
was added to reduce the amount of vegetation that would have to be
cleared, present additional opportunities for forest enhancement
mitigation, maintain the natural buffer area between developed areas
and nearby sensitive coastal resources (e.g., Haputo Ecological Reserve
Area), and leverage existing family housing support facilities already
in place at Andersen AFB (JGPO-NavFac, Pacific 2015, p. ES-15; http://guambuildupeis.us/). Finegayan and Northwest Field on Andersen AFB
collectively support 16 of the 23 species or their habitats (11 of the
14 plants: Bulbophyllum guamense, Cycas micronesica, Dendrobium
guamense, Eugenia bryanii, Heritiera longipetiolata, Maesa walkeri,
Nervilia jacksoniae, Psychotria malaspinae, Solanum guamense,
Tabernaemontana rotensis, and Tuberolabium guamense; and 5 of the 9
animals: The Mariana eight-spot butterfly, the Mariana wandering
butterfly, the Guam tree snail, the humped tree snail, and the fragile
tree snail) (JGPO-NavFac, Pacific 2014, pp. ES-18--ES-22; JGPO-NavFac,
Pacific 2015, p. ES-11; http://guambuildupeis.us/).
The Final SEIS describes: (1) More moderate construction activity
over 13 years instead of a 7-year intense construction boom; (2) a
significant reduction in projected peak population increase (from
79,000 to less than 10,000) and steady state population increase (from
33,000 to approximately 7,400); (3) a reduction in the project area at
Finegayan from 2,580 ac (1,044 ha) to 1,213 ac (491 ha); (4)
utilization of 510 ac (206 ha) of existing infrastructure on Andersen
AFB for family housing; (5) no new land acquisition; (6) a reduction in
project area at Northwest Field (instead of Route 15); and (7) an
overall decrease in power and water demands (JGPO-NavFac, Pacific 2014,
p. ES-3; JGPO-NavFac, Pacific 2015, p. ES-11; http://guambuildupeis.us/
).
Concurrent with the relocation efforts discussed above, the U.S.
Marine Corps (the Executive Agent designated by the U.S. Pacific
Command) published their ``Commonwealth of the Northern Mariana Islands
(CNMI) Joint Military Training (CJMT) Draft Environmental Impact
Statement (EIS)-Overseas Environmental Impact Statement (OEIS)''
(herein referred to as the ``CJMT Draft EIS-OEIS'') (CNMI Joint
Military Training Draft EIS-OEIS at http://www.cnmijointmilitarytrainingeis.com/about). The 2015 Draft CJMT EIS-
OEIS informs the public that the military has proposed plans to use
Tinian and Pagan to establish a series of live-fire range training
areas, training courses, and maneuver areas to reduce existing joint
service training deficiencies and meet the U.S. Pacific Command Service
Components' unfilled unit level and combined level training
requirements in the Pacific (2015 CNMI Joint Military Training Draft
EIS-OEIS at http://www.cnmijointmilitarytrainingeis.com/about).
[[Page 59430]]
The northern two-thirds of Tinian are leased to the Department of
Defense (DOD), and the development of these lands will negatively
impact the habitat of 2 of the 23 species addressed in this final rule,
the plant Heritiera longipetiolata, and the humped tree snail.
Likewise, live-fire training on Tinian will negatively impact the
habitat and individuals of H. longipetiolata and the humped tree snail.
On Pagan, both Alternative 1 and Alternative 2 claim the entire island
for training purposes, with the north dedicated to live-fire maneuver
areas, and the south dedicated to non-live-fire maneuver areas (CJMT
Draft EIS-OEIS http://www.cnmijointmilitarytrainingeis.com/about). If
the entire island of Pagan is used for training purposes, it will
negatively impact 2 of the 16 species listed as endangered species in
this final rule, Slevin's skink and the humped tree snail, and their
habitats. Additionally, Cycas micronesica may be present on Pagan,
although this is not yet confirmed. If Cycas micronesica is confirmed
on Pagan, then this species would be considered negatively impacted by
ordnance and live-fire training on both Guam and Pagan.
Additionally the entire Mariana archipelago is located within the
Mariana Islands Training and Testing (MITT) Study Area, which comprises
air, land, and sea space, and includes the existing Mariana Islands
Range Complex (MIRC), its surrounding seas, and a transit corridor
between the MIRC and the Navy's Hawaii Range Complex, where training
and testing activities may occur. The MIRC is the only Navy range
complex in the MITT Study Area (JGPO-NavFac, Pacific 2013, pp. 1-3;
Mariana Islands Training and Testing http://mitt-eis.com/EISOEIS/Background.aspx). The MITT Study Area opens up every island within the
Mariana Archipelago as a potential training site (Mariana Islands
Training and Testing http://mitt-eis.com/EISOEIS/Background.aspx),
which subsequently may result in negative impacts to any number of the
23 species addressed in this final rule. Proposed actions include
increases in training activities on Guam, Rota, Saipan, Tinian,
Farallon de Medinilla (increase in bombing), and Pagan. Likely negative
impacts include, but are not limited to, direct damage to individuals
from live-fire training and ordnance, wildfire resulting from live-fire
and ordnance, direct physical damage (e.g., trampling by humans,
helicopter landing, etc.) to individuals, and spread of nonnative
species. Additionally, water purification training is proposed for all
of these islands, except Farallon de Medinilla, which may be
particularly damaging to the Rota blue damselfly, for which the only
known location exists along the freshwater streams of the Talakhaya
watershed.
In addition to military spending, Guam's economy depends on
tourism. More than one million tourists visit Guam annually, mostly
arriving from Japan, Korea, and other Asian countries. In the early
1960s, military contributions to Guam's economy approached 60 percent,
with tourism adding almost another 30 percent. There was a downturn in
military presence in the 70s and 80s. Also at this time, the growth of
a private economy occurred, fueled by tourism (Guampedia http://www.guampedia.com/evolution-of-the-tourism-industry-on-guam-2/,
Accessed April 23, 2015). Currently, tourism accounts for about 60
percent of Guam's annual business revenue and 30 percent of all non-
Federal jobs (Guam Visitor Bureau 2014, p. 3; http://www.guamvisitorsbureau.com/, accessed April 25, 2014; http://guampedia.com/evolution-of-the-tourism-industry-on-guam-2/#toc-consequences-and-conclusions, accessed April 25, 2014).
An increase in human population, whether from tourism or a military
presence, also increases the type and intensity of stressors on
endangered and threatened species. These stressors range from increased
development, which results in loss of habitat, to increased risk for
introduction of harmful nonnative species, which directly or indirectly
impact native species and their habitats. As Guam is seeking a ``no
visa required'' status for visitors from Russia and China (Guam Visitor
Bureau 2014, p. 33), monitoring of sea ports and airports against
inadvertent introduction of harmful and invasive species is especially
important (see ``Factor D. The Inadequacy of Existing Regulatory
Mechanisms''). The proposed increase in military training activities
throughout the Marianas heightens the importance for enhanced
monitoring at these sites.
Political Division
Micronesia is made up of six island groups: (1) Mariana Islands;
(2) Caroline Islands, consisting of the sovereign island nation of the
Federated States of Micronesia (Yap, Chuuk, Pohnpei, and Kosrae) and
the independent island nation of the Republic of Palau; (3) Gilbert
Islands (politically the Republic of Kiribati); (4) Marshall Islands
(politically the Republic of the Marshall Islands); (5) Nauru
(politically the Republic of Nauru, the world's smallest republic,
consisting of a single phosphate rock island); and (6) Wake Island
(also known as Wake Atoll, an unorganized, unincorporated territory of
the United States). Micronesia, together with Polynesia, is described
as the ``Polynesia-Micronesia Hotspot,'' reflecting the fact that these
island groups contain an exceptional concentration of endemic (found
nowhere else in the world) species, and are currently experiencing
exceptional habitat loss (Myers et al. 2000, pp. 853-858) (see Summary
of Biological Status and Threats Affecting the 23 Mariana Islands
Species, below).
Islands in the Mariana Archipelago
Please see the proposed rule (79 FR 59364; October 1, 2014) for a
description of each of the 14 Mariana Islands; a map of the islands is
included here as Figure 1. The below island descriptions are included
in this final rule because they include at least one substantial change
since publication of the proposed rule. These sections reflect new
information received during the two comment periods on the proposed
rule.
Guam
Guam is the largest and southernmost island of the Mariana Islands.
It is nearly 31 miles (mi) (50 kilometers (km)) long and from 4 to 9 mi
(7 to 15 km) wide, with a peak elevation of 1,332 feet (ft) (406 meters
(m)) at Mt. Lamlam (Muller-Dombois and Fosberg 1998, p. 269). Guam is
located in the northwestern Pacific Ocean, 1,200 mi (1,930 km) east of
the Philippines, 3,500 mi (5,632 km) west of the Hawaiian Islands, and
54 mi (87 km) south of Rota. The northern and southern regions of the
island show marked contrast due to their geologic history. The northern
region is an extensive, upraised, terraced, limestone plateau or
``mesa'' between 300 and 600 ft (90 and 180 m) above sea level
interrupted by a few low hills, of which two (Mataguac and Mt. Santa
Rosa) are volcanic in nature, while others are exclusively coralline
limestone (e.g., Barrigada Hill and Ritidian Point (Stone 1970, p.
12)). The southern region is primarily volcanic material (e.g.,
basalts) with several areas capped by a layer of limestone (Stone 1970,
p. 12).
Of all the Mariana Islands, Guam contains the most extensive stream
and drainage systems, particularly in the Talofofo Region (Stone 1970,
p. 13; Muller-Dombois and Fosberg 1998, p. 269). Fairly extensive
wetland areas are located on both coasts of the southern region as well
as at Agana Swamp
[[Page 59431]]
located in the middle of the island. Guam is also the most populated of
all the Mariana Islands, with an estimated 170,000 residents. Guam has
experienced impacts from at least 4,000 years of human contact,
starting with the Chamorro, followed by the Spanish, Germans, Japanese,
and Americans (see ``Pre-Historical Human Impact'' and ``Historical
Human Impact,'' above). World War II and subsequent U.S. military
activity have also negatively impacted natural habitats on Guam;
however, the buffer zones around the U.S. Navy and Air Force bases on
Guam and conservation areas designated on these bases support some of
the last remaining intact native habitats and subsequently some of the
last remaining individuals of the rarest species. There are three
conservation areas on the island designated by the Guam Department of
Aquatic and Wildlife Resources (GDAWR): (1) Anao Conservation Area; (2)
Bolanos Conservation Area; and, (3) Cotal Conservation Area (GDAWR
2006, p. 39; Sablan Environmental, Inc. 2008, p. 3). Guam supports the
forest, savanna, stream, and cave ecosystems (see ``Mariana Islands
Ecosystems,'' below). Twenty of the 23 species addressed in this final
rule occur on Guam (all 14 plants: Bulbophyllum guamense, Cycas
micronesica, Dendrobium guamense, Eugenia bryanii, Hedyotis megalantha,
Heritiera longipetiolata, Maesa walkeri, Nervilia jacksoniae,
Phyllanthus saffordii, Psychotria malaspinae, Solanum guamense,
Tabernaemontana rotensis, Tinospora homosepala, and Tuberolabium
guamense; and 5 of the 9 animals: Slevin's skink (Cocos Island, off
Guam), the Mariana eight-spot butterfly, the Guam tree snail, the
humped tree snail, and the fragile tree snail. The Pacific sheath-
tailed bat (Mariana subspecies) and the Mariana wandering butterfly
occurred on Guam historically.
Rota
Just northeast of Guam (36 mi; 58 km) and southwest of Aguiguan (47
mi; 76 km), Rota is the fourth largest island in the Mariana Islands,
measuring 33 square miles (mi\2\) (96 square kilometers (km\2\)) in
land area (Mueller-Dombois and Fosberg 1998, p. 265; CNMI Statewide
Assessment and Resource Strategy Council (CNMI-SWARS) 2010, p. 6). The
highest point on the island is Mount Sabana (also referred to as the
Sabana plateau or simply the Sabana), at just over 1,600 ft (488 m)
(Mueller-Dombois and Fosberg 1998, p. 265). The Sabana plateau is
characterized by a savanna ringed by forest that extends onto the
surrounding karst limestone cliffs and down the rugged slopes that
encircle all sides of the Sabana (Mueller-Dombois and Fosberg 1998, pp.
265-266). Rota consists primarily of terraced limestone surrounding a
volcanic core that protrudes from the topmost plateau, or Sabana. The
Sabana is noticeably wetter than the rest of the island and is the only
location known to support all four orchids listed as threatened species
in this final rule (Bulbophyllum guamense, Dendrobium guamense,
Nervilia jacksoniae, and Tuberolabium guamense) (Harrington et al.
2012, in litt.).
Rota has experienced land alterations since the arrival of the
first Chamorro more than 4,000 years ago. When the Mariana Islands were
occupied by the Japanese (1914-1944), they cleared forest areas to
plant large sugarcane plantations and conducted phosphate mining on the
Sabana plateau (Amidon 2000, pp. 4-5; Engbring et al. 1986, pp. 10,
27). Although Rota was never invaded during World War II, it was
heavily bombed by U.S. military forces (Engbring et al. 1986, pp. 8,
11). Rota has a population of approximately 3,000 people. In recent
years, three terrestrial conservation areas have been designated on
Rota by the CNMI Department of Land and Natural Resources (DLNR): (1)
The Sabana Wildlife Conservation Area (which includes the Sabana
Heights Conservation Area and the Talakhaya Conservation Area); (2)
Mariana Crow Conservation Area and Bird Sanctuary; and (3) Wedding Cake
Wildlife Conservation Area (Berger et al. 2005, p. 14). Rota supports
the forest, savanna, stream, and cave ecosystems. Eleven of the 23
species addressed in this final rule currently occur on Rota (8 of the
14 plants: Bulbophyllum guamense, Cycas micronesica, Dendrobium
guamense, Heritiera longipetiolata (recently rediscovered; formerly
thought extirpated from Rota), Maesa walkeri, Nervilia jacksoniae,
Tabernaemontana rotensis, and Tuberolabium guamense; and 4 of the 9
animals: The Mariana wandering butterfly, the Rota blue damselfly, the
fragile tree snail, and the humped tree snail). The plant Solanum
guamense, and the Pacific sheath-tailed bat (Mariana subspecies), were
known from Rota historically.
Aguiguan
Aguiguan is known as ``Goat Island'' due to the presence of a large
feral goat population (Engbring et al. 1986, p. 8). Located
approximately 8 km (5 mi) southwest of Tinian, Aguiguan is a small
uninhabited island measuring 7 mi\2\ (18 km\2\) in land area with a
peak elevation of 515 ft (157 m) at Mt. Alutom (CNMI-SWARS 2010, p. 6).
This island was historically inhabited by the Chamorro people (Russell
1998, pp. 90-91). Aguiguan is entirely limestone, with very steep
cliffs fringing nearly the entire island, making access difficult
(Berger et al. 2005, p. 36). There are no streams on the island
(Engbring et al. 1986, p. 8). During the Japanese occupation, large
areas of native forest were cleared for sugarcane plantations, a large
runway and other war-related structures (Engbring et al. 1986, p. 8;
Mueller-Dombois and Fosberg 1998, p. 264). Ecosystem types on Aguiguan
include forest and cave. Four of the 23 species addressed in this final
rule occur on Aguiguan: the plant Dendrobium guamense (recently
discovered for the first time on Aguiguan); and the Pacific sheath-
tailed bat (Mariana subspecies), humped tree snail, and Langford's tree
snail. The plant Tuberolabium guamense was known from Aguiguan
historically.
Tinian
Located approximately 3 mi (5 km) southeast of Saipan and 7 mi (9
km) north of Aguiguan, Tinian is the third largest island in the
Mariana Islands, measuring 40 mi\2\ (101 km\2\) in area, with a peak
elevation of 584 ft (178 m) at Lasso Hill (Engbring et al. 1986, p. 5).
The island of Tinian has a population of over 3,000 residents. Tinian's
climate is the same as that of Guam (see ``The Mariana Islands,''
above). The island is predominantly limestone with low-lying plateaus
and ridges, and lacks surface streams (Stafford et al. 2005, p. 15;
Engbring et al. 1986, p. 5). There are two small wetland areas, heavily
overgrown with no open water, Hagoi Marsh and Marpo Swamp, which serve
as a domestic water source (Engbring et al. 1986, p. 5). Tinian has
lost most of its primary (native) forest, due initially to clearing for
agriculture by the Chamorro, followed by agricultural endeavors of
German colonialists in the early 1900s (e.g., coconut plantations) and
then by Japanese settlers after 1914 (e.g., sugarcane plantations)
(Berger et al. 2005, pp. 36-37). Impacts to Tinian's native vegetation
were then compounded by impacts from military activities during World
War II (Mueller-Dombois and Fosberg 1998, p. 262; Russell 1998, p. 98;
CNMI-SWARS 2010, pp. 6-7, 28-29). Currently, approximately 5 percent of
primary (native) forest remains on Tinian (Engbring et al. 1986, p.
25), predominantly along the southeastern portion of Tinian (Spaulding
2013, in litt.; Spaulding 2015, in litt.). Tinian supports the forest
and cave ecosystems. Tinian currently has no designated conservation
areas. Three of the 23
[[Page 59432]]
species addressed in this final rule occurs on Tinian, the plants
Dendrobium guamense and Heritiera longipetiolata and the humped tree
snail (recently rediscovered; formerly thought extirpated from Tinian).
The plants Solanum guamense and Tuberolabium guamense and the Pacific
sheath-tailed bat (Mariana subspecies) were known from Tinian
historically.
Saipan
Located approximately 3 mi (4.5 km) northeast of Tinian, Saipan is
the second largest and second most populous of the Mariana Islands,
measuring 44 mi\2\ (115 km\2\) with a peak elevation of 1,555 ft (474
m) at Mt. Tapochau (Mueller-Dombois and Fosberg 1998, p. 256). The
island is composed primarily of terraced limestone peaks, with exposed
volcanic ridges and slopes (Mueller-Dombois and Fosberg 1998, p. 256).
Saipan supported a large population of Chamorro people for thousands of
years, followed by the Spanish, Germans, Japanese, and the U.S.
military forces, and was also heavily impacted by World War II. Saipan
is the site of one of the largest battles in the Pacific between U.S.
and Japanese forces. Much of Saipan's forests were destroyed during
World War II, with only pockets of native forest surviving (Engbring et
al. 1986, pp. 3-5, 10-12; Berger et al. 2005, pp. 38-39). Due to this
widespread destruction of native forests and subsequent erosion, the
nonnative tree Leucaena leucocephala (tangantangan) was seeded for
erosion control (Berger et al. 2005, p. 32). Tangantangan is now a
dominant tree species on the island, and the CNMI Division of Forestry
has suggested it forms a unique mixed forest habitat on Saipan not
reported from the other islands (CNMI-SWARS 2010, p. 7). There are six
conservation areas on Saipan: (1) Bird Island Wildlife Conservation
Area; (2) Kagman Wildlife Conservation Area and Forbidden Island
Sanctuary; (3) Marpi Commonwealth Forest; (4) Nightingale Reed-Warbler
Conservation Area; (5) Micronesian Megapode Conservation Area; and (6)
the Saipan Upland Mitigation Bank (Berger et al. 2005, p. 14).
Ecosystem types on Saipan include forest, savanna, and cave. One of the
23 species addressed in this final rule occurs on Saipan, the humped
tree snail. The plants Bulbophyllum guamense, Dendrobium guamense, and
Solanum guamense, the Pacific sheath-tailed bat (Mariana subspecies),
and the Mariana eight-spot butterfly were known from Saipan
historically.
Pagan
Located 42 mi (68 km) from Agrihan and 30 mi (48 km) from Alamagan,
Pagan is the fifth largest island in the Marianas archipelago, and the
largest of the northern Mariana Islands, with an area of 19 mi\2\ (48
km\2\) (Ohba 1994, p. 17). Four volcanoes comprise Pagan: Mt. Pagan in
the north, and an unnamed complex of three older volcanoes to the south
(Ohba 1994, p. 17; Smithsonian Institution 2014a, in litt.). These
volcanoes are connected by a narrow isthmus. The highest point on this
island is Mt. Pagan, which rises 1,870 ft (570 m) above sea level. Mt.
Pagan is one of the most active volcanoes in the Mariana Islands, with
its most recent eruption in 2012 (Smithsonian Institution 2014b, in
litt.). The largest eruption during historical times took place in
1981, when lava buried 10 percent of the island, and ash covered the
entire island, forcing the 53 residents to flee to Saipan (Smithsonian
Institution 2014b, in litt.). The island of Pagan supports the forest
and savanna ecosystems. Two of the 23 species are known to occur on
Pagan, the animals Slevin's skink and the humped tree snail. The tree
Cycas micronesica also likely occurs on Pagan; however, this is not yet
confirmed (see Cycas micronesica under Description of the 23 Mariana
Islands Species, below). The plant Bulbophyllum guamense occurred
historically on Pagan.
The descriptions for each of the remaining northern islands in the
Mariana Archipelago remain unchanged from the proposed rule and,
therefore, are not included in this final rule. Please refer to the
proposed rule (79 FR 59364; October 1, 2014) for further information.
An Ecosystem-Based Approach to Organizing This Listing Rule
In the Mariana Islands, as within most archipelagos, native species
that occur in the same habitat types (ecosystems) depend on many of the
same biological features and the successful functioning of that
ecosystem to survive. We have, therefore, organized the species
addressed in this final rule by common ecosystems. Although the listing
determination for each species is analyzed separately, we have
organized the individual analysis for each species within the context
of the broader ecosystem in which it occurs for efficiency and to
reduce repetition for the reader. In addition, native species that
share ecosystems often face a suite of common factors that may be a
threat to them, and ameliorating or eliminating these threats for each
individual species often requires the same management actions in the
same areas. Cost-effective management of these threats often requires
implementation of conservation actions at the ecosystem level to
enhance or restore critical ecological processes and provide long-term
viability of species and their habitat. Organizing the 23 Mariana
Islands species by shared ecosystems may also set the stage for a
conservation management approach of protecting, restoring, and
enhancing critical ecological processes at an ecosystem scale for the
long-term viability of all associated native species in a given
ecosystem type and locality, thus potentially preventing the future
imperilment of any additional species that may require protection.
Based on the best available scientific and commercial data,
including information received during the comment period on our
proposed rule (79 FR 59364; October 1, 2014), we are listing the plants
Eugenia bryanii, Hedyotis megalantha, Heritiera longipetiolata,
Phyllanthus saffordii, Psychotria malaspinae, Solanum guamense, and
Tinospora homosepala; and the animals Pacific sheath-tailed bat
(Mariana subspecies), Slevin's skink, Mariana eight-spot butterfly,
Mariana wandering butterfly, Rota blue damselfly, humped tree snail,
Langford's tree snail, Guam tree snail, and fragile tree snail from the
Mariana Islands, as endangered species. We are listing the plants
Bulbophyllum guamense, Cycas micronesica, Dendrobium guamense, Maesa
walkeri, Nervilia jacksoniae, Tabernaemontana rotensis, and
Tuberolabium guamense, from the Mariana Islands and greater Micronesia,
as threatened species.
These 23 Mariana Islands species are found in four ecosystem types:
Forest, savanna, stream, and cave (Table 2). Of the 23 species, only
the Pacific sheath-tailed bat (Mariana subspecies) is found in more
than one ecosystem type (forest and cave).
[[Page 59433]]
Table 2--The 23 Mariana Islands Species and the Ecosystems Upon Which
They Depend
------------------------------------------------------------------------
Species
Ecosystem ------------------------------------
Plants Animals
------------------------------------------------------------------------
Forest............................. Bulbophyllum Pacific sheath-
guamense. tailed bat
(Mariana
subspecies).
Cycas micronesica Slevin's skink.
Dendrobium Mariana eight-
guamense. spot butterfly.
Eugenia bryanii.. Mariana
wandering
butterfly.
Heritiera Humped tree
longipetiolata. snail.
Maesa walkeri.... Langford's tree
snail.
Nervilia Guam tree snail.
jacksoniae.
Psychotria Fragile tree
malaspinae. snail.
Solanum guamense.
Tabernaemontana
rotensis.
Tinospora
homosepala.
Tuberolabium
guamense.
Savanna............................ Hedyotis
megalantha.
Phyllanthus
saffordii.
Stream............................. ................. Rota blue
damselfly.
Cave............................... ................. Pacific sheath-
tailed bat
(Mariana
subspecies).
------------------------------------------------------------------------
For each species, we identified and evaluated those factors that
are threats to each individual species specifically (species-specific
threats), as well as those factors which pose common threats to all of
the species of a given ecosystem type (ecosystem-level threats). For
example, the degradation of habitat by nonnative ungulates is
considered a direct or indirect threat to 17 of the 23 species listed
as endangered or threatened in this final rule. We have labeled such
threats that are shared by all species within the same ecosystem as
``ecosystem-level threats,'' because they impact all species inhabiting
that ecosystem type in terms of the nature of the impact, its severity,
timing, and scope. Beyond ecosystem-level threats, we further
identified and evaluated species-specific threats that may be unique to
certain species, and not shared by all other species in the same
ecosystem. For example, the threat of predation by nonnative flatworms
is unique and specific to the four tree snails addressed in this final
rule.
Mariana Islands Ecosystems
As noted above, for the purposes of organizing our threats
discussion for the 23 species by shared habitats, we have identified
four broad Mariana Islands ecosystems: forest, savanna, stream, and
cave, based on physical features, elevation, substratum, vegetation
type, and hydrology (see The Mariana Islands, above; and the proposed
rule (79 FR 59364; October 1, 2014)). We acknowledge the presence of
other ecosystems (e.g., coastal, wetland) in the Mariana Islands,
however, we limit our discussion to these four because they are the
relevant ecosystems that support the 23 species listed as endangered or
threatened species in this final rule. These four ecosystems are
described in the proposed rule (79 FR 59364; October 1, 2014) and these
descriptions are hereby incorporated into this final rule, with the
exception of a revised description of the forest ecosystem, below; see
Table 2 (above) for a list of the species that occur in each ecosystem
type.
Forest Ecosystem
There are two substrate types in the forest ecosystem, limestone
and volcanic (Stone 1970, pp. 9, 14, 18-24; Falanruw et al. 1989, pp.
6-9; Ohba 1994, pp. 19-29; Mueller-Dombois and Fosberg 1998, p. 243).
The annual rainfall in the forest ecosystem lies within the archipelago
average, ranging from 78 to 100 inches (in) (2,000 to 2,500 millimeters
(mm)), with a rainy season from June or July through October or
November. The temperature of the forest ecosystem mirrors the
archipelago monthly averages, between 75 degrees Fahrenheit ([deg]F)
and 82 [deg]F (24 degrees Celsius ([deg]C) and 28 [deg]C), with
extremes of 64 [deg]F and 95 [deg]F (18 [deg]C and 35 [deg]C). There
are multiple plant species present throughout the forest ecosystem, and
on most of the islands; however, variations in species structure are
observed (Fosberg 1960, pp. 37, 56-59, plates 1-40; Falanruw et al.
1989, pp. 6-9; Ohba 1994, pp. 19-29; Mueller-Dombois and Fosberg 1998,
pp. 257, 268, 270-271).
Native canopy species in the forest ecosystem (as defined here)
include but are not limited to: Artocarpus mariannensis, Barringtonia
asiatica, Claoxylon spp., Cordia subcordata, Cyanometra ramiflora,
Elaeocarpus joga, Ficus prolixa, Hernandia labyrinthica, H. sonora,
Merrilliodendron megacarpum, Ochrosia mariannensis, O. oppositifolia,
Pandanus dubius, P. tectorius, Pisonia grandis, Pouteria obovata, and
Premna obtusifolia (Falanruw et al. 1989, pp. 6-9; Raulerson and
Rinehart 1991, pp. 6-7, 11, 14, 20, 24, 28, 33, 50, 52-53, 62-63, 72,
91, 96, 104; Ohba 1994, pp. 19-29; Mueller-Dombois and Fosberg 1998,
pp. 257, 268, 270-271; Wiewel et al. 2009, pp. 206-207). Native
subcanopy species include but are not limited to: Aglaia mariannensis,
Aidia cochinchinensis, Allophylus timoriensis, Eugenia palumbis, E.
reinwardtiana, Hibiscus tiliaceus, Maytenus thompsonii, Meiogyne
cylindrocarpa, Psychotria mariana, and Xylosma nelsonii (Stone 1970,
pp. 9, 14, 18-24; Falanruw et al. 1989, pp. 6-9; Raulerson and Rinehart
1991, pp. 13, 47, 56, 59, 68-69, 77, 84, 88; Ohba 1994, pp. 19-29;
Mueller-Dombois and Fosberg 1998, pp. 252-253, 257, 268, 272); and
native understory species include but are not limited to: Discocalyx
megacarpa, Hedyotis spp., Nephrolepis bisserrata, N. hirsutula,
Phyllanthus marianus, and Piper guamense (Falanruw et al. 1989, pp. 6-
9; Ohba 1994, pp. 19-29; Mueller-Dombois and Fosberg 1998, pp. 247,
268). Further, in select areas of the forest ecosystem, usually where
the forest is situated such that it receives and retains more moisture,
the canopy trees are covered in various mosses and epiphytic ferns and
orchids (Mueller-Dombois and Fosberg 1998, p. 268).
Dominant canopy, subcanopy, and understory species can vary from
one location to the next on the same island, and from island to island.
These species can be endemic to one island, occur on one or more of the
southern islands, or occur on one or more of the northern islands. In
addition, biologists have
[[Page 59434]]
observed overlap of forest species on limestone and volcanic substrata,
suggesting that physical properties may be more important than chemical
properties of these substrates in determining vegetation
characteristics (Mueller-Dombois and Fosberg 1998, p. 243). Elevation
also contributes to variations in vegetation, as observed on Mt.
Alutom, Mt. Almagosa, Mt. Lamlam, and Mt. Bolanus on Guam; the Rota
Sabana; and on the slopes of the northern islands (Stone 1970, pp. 9,
14, 18-24; Falanruw 1989, pp. 4-6; Mueller-Dombois and Fosberg 1998,
pp. 262-264); although in some cases there is no definite correlation
with elevation (i.e., the moisture-retaining, moss- and epiphyte-
covered sections of the forest ecosystem are found near the coast in
some areas and also at mid to high elevations) (Fosberg 1960, p. 30).
Additionally, biologists have observed a change in distribution of
Hernandia species with elevation. For example, H. sonora, dominant on
the coastal side of the forest ecosystem, changes distinctly to H.
labyrinthica as the elevation increases (Falanruw et al. 1989, p. 8;
Amidon 2000, p. 49). The significance of these interpretations of
forest-associated species in the Mariana archipelago to the 14 plants
in this rule is not adequately definitive to subclassify a forest type
for each of the species in this rule; therefore, we describe a general
forest ecosystem here, with the substrate, temperatures, precipitation,
and associated native canopy, subcanopy, and understory species, listed
above. The forest ecosystem supports 20 of the 23 species listed as
endangered or threatened species in this final rule (all except the
plants Hedyotis megalantha and Phyllanthus saffordii, which occur only
in the savanna ecosystem, and the Rota blue damselfly, which occurs
only in the stream ecosystem).
Description of the 23 Mariana Islands Species
Plants
In order to avoid confusion regarding the number of populations of
each species (i.e., because we do not consider an individual plant to
represent a viable population), we use the word ``occurrence'' instead
of ``population.'' Additionally, we use the word occurrence to refer
only to wild (i.e., not propagated and outplanted) individuals because
of the uncertainty of the persistence to at least the second generation
(F2) of the outplanted individuals. A population consists of mature,
reproducing individuals forming populations that are self-sustaining
(as indicated, for example, by the presence of individuals representing
multiple life-history stages). Also, there is a high potential that one
or more of the outplanted populations may be eliminated by normal or
random adverse events, such as fire, nonnative plant invasion, or
disease, before a seed bank can be established.
Bulbophyllum guamense (siboyas halumtanu, siboyan halom tano), an
epiphyte in the orchid family (Orchidaceae), is known from widely
distributed occurrences on the southern Mariana Islands of Guam and
Rota, in the forest ecosystem (Ames 1914, p. 13; Raulerson and Rinehart
1992, p. 90; Costion and Lorence 2012, pp. 54, 66; Global Biodiversity
Information Facility (GBIF) 2012a--Online Herbarium Database; Zarones
et al. 2015c, in litt.). Bulbophyllum guamense was recorded
historically on Guam from clifflines encircling the island, and on the
slopes of Mt. Lamlam and Mt. Almagosa. As recently as 1992, this
species was reported to occur in large mat-like formations on trees
``all over the island,'' (Guam) (Raulerson and Rinehart 1992, p. 90).
Currently, there are 12 known occurrences (3 on Guam and 9 on Rota)
totaling fewer than 250 individuals on Guam and at least 261
individuals on Rota. At the time of the proposed rule, our information
indicated that there were likely fewer than 30 individuals of this
species on Rota. However, a recent survey team on Rota reported at
least 261 individuals of B. guamense along the Sabana tableland and
slopes above 980 ft (300 m) elevation with a population structure
consisting of seedlings, juveniles, and flowering adults. This survey
team estimated the overall number of individuals could be as high as
16,000. This latter estimate appears to be an assumption based on the
premise that B. guamense is uniformly distributed across the region in
preferred habitat areas (Zarones et al. 2015c, in litt.).
The Service does not concur that there are enough data to determine
that this species is uniformly distributed across the Sabana, and
subsequently cannot support the extrapolation of numbers for this
species to be as high as 16,000, although it is possible. The healthy
population structure of B. guamense recently observed on Rota, with
multiple generations of plants present, does show that the status of
this species is better on this island than previously understood.
Historically, there are a couple of herbarium records of B. guamense
occurring on Pagan (last observed in 1984) and Saipan (last observed in
1970), however, these are considered outliers and not within the
accepted endemic range of B. guamense. Due to the common occurrence of
errors detected throughout the herbaria records and literature, the
Service recognizes Guam and Rota as the most scientifically credible
range for this species. Bulbophyllum guamense has declined in number of
populations and individuals on Guam, which represents half of its known
range, and the species exists in a specialized niche habitat within the
forest ecosystem on Rota. The remaining individuals of B. guamense are
vulnerable to the effects of continued habitat loss and destruction
from agriculture, urban development, nonnative animals and plants,
fires, and typhoons, combined with predation by nonnative invertebrates
such as slugs. We anticipate the effects of climate change will further
exacerbate many of these threats in the future.
Cycas micronesica (fadang, faadang), a cycad in the cycad family
(Cycadaceae), is known from Guam, Rota, and tentatively on Pagan, as
well as Palau (politically the independent Republic of Palau) and Yap
(geographically part of the Caroline Islands; politically part of the
Federated States of Micronesia), in the forest ecosystem (Hill et al.
2004, p. 280; Keppel et al. 2008, p. 1,006; Cibrian-Jaramillo et al.
2010, pp. 2,372-2,375; Marler 2013, in litt.).
Just 10 years ago, Cycas micronesica was ubiquitous on the island
of Guam, and similarly common on Rota. Cycas micronesica is currently
under attack by a nonnative insect, the cycad aulacaspis scale
(Aulacaspis yasumatsui) that is causing rapid mortality of plants at
all locations (Marler 2014, in litt.). As of January 2013, C.
micronesica mortality reached 92 percent on Guam, and cycads on Rota
are experiencing a similar fate (Marler 2013, in litt.). All seedlings
of C. micronesica in a study area were observed to die within 9 months
of infestation by A. yasumatsui (see ``Factor C. Disease and
Predation,'' below for further discussion) (Marler and Muniappan 2006,
p. 3; Marler and Lawrence 2012, p. 233; Western Pacific Tropical
Research Center 2012, p. 4; Marler 2013, pers. comm.).
Currently, there are 15 to 20 occurrences of Cycas micronesica
totaling 900,000 to 950,000 individuals on the Micronesian Islands of
Guam, Rota, Yap, and Palau. There may be a small number of individuals
on Pagan; however, this is not yet confirmed. On Guam and Rota there
are fewer than 630,000 (Marler 2013, pers. comm.). These totals do not
distinguish between successfully reproducing adults and juveniles
(Marler 2013, pers. comm.),
[[Page 59435]]
which, because of the effects of the cycad aulacaspis scale, implies
that the number of extant individuals that can successfully reproduce
is much lower. On Guam, there are four fragmented occurrences, totaling
fewer than 516,000 individuals: One occurrence along the shoreline to
the base of the limestone cliffs on the north side; a second occurrence
beginning at the forest edge along the cliffs and continuing into the
forest on the north side; a third occurrence on the northern plateau;
and a fourth occurrence along the ravines and rock outcrops on the
southern side, with a few individuals occurring across the savanna.
On Rota, there are four known occurrences within the forest
ecosystem, totaling fewer than 111,500 individuals (Marler 2013, in
litt.). On the northeast shore the first occurrence totals fewer than
25,500 individuals; the second occurrence, on the northwest shore,
totals fewer than 21,600 individuals; the third occurrence on the south
shore totals fewer than 63,600 individuals; and the fourth occurrence
on Wedding Cake peninsula totals fewer than 300 individuals.
There are likely a relatively limited number of individuals of
Cycas micronesica on Pagan. In recent surveys, Pratt (2011, pp. 33-42)
reported finding Cycas circinalis in a ravine on the southwest part of
the island. Cycas micronesica was once merged with C. rumphii or C.
circinalis, but is now considered a separate species (Hill 1994, pp.
543-567; Hill et al 2004, p. 280). It is more likely that this cycad
species on Pagan is C. micronesica; however, until identification is
confirmed, we consider this a tentative location.
Yap consists of a group of four islands, three of which are
separated by water but share a common reef, with a total land area of
39 mi\2\ (102 km\2\). On Yap, there are three occurrences of Cycas
micronesica, totaling 288,450 individuals (Marler 2013, in litt). Palau
consists of three larger islands, Babeldaob, Koror, and Ngeruktabel,
and between 250 and 300 smaller islands referred to as the ``Rock
Islands.'' The total land area is 177 mi\2\ (458 km\2\). On Palau,
there are four occurrences of C. micronesica totaling fewer than 2,500
individuals: (1) Two occurrences on Ngeruktabel Island, totaling fewer
than 900 individuals, (2) one occurrence on Ngesomel Island totaling
fewer than 600 individuals, and (3) possibly as many as 1,000
individuals scattered on the Rock Islands (Marler 2013, in litt.). The
aulacaspis scale was observed on the main islands of Palau in 2008
(Marler 2014, in litt.), and is expected to reach Yap as well (Marler
2013, in litt.).
The nonnative cycad aulacaspis scale quickly causes mortality of
all life stages of C. micronesica, preventing reproduction of C.
micronesica, and leading to its extirpation (see ``Factor C. Disease
and Predation,'' below). The magnitude of the ongoing threats of
predation by the scale and nonnative animals, secondary infestations by
other insects, and loss of habitat due to development, typhoons, and
direct damage and destruction by military live-fire training is large,
and these threats are imminent. We anticipate the effects of climate
change will further exacerbate many of these threats in the future.
Although C. micronesica presently is found in relatively high numbers,
the factors affecting this species can result in very rapid mortality
of large numbers of individuals. A study by Marler and Lawrence (2012,
pp. 239--240) shows that if the ongoing negative population density
trajectory for C. micronesica established over 4 years is sustained,
extirpation of C. micronesica from Guam and Rota will occur by 2019.
Marler and Lawrence's data show that it is reasonable to conclude that,
unless an effective biocontrol is discovered, the scale will similarly
impact the three populations of C. micronesica in the Rock Islands of
Palau within several years. Additionally, frequent travel between Guam
and Yap increases the likelihood that the scale will reach Yap in the
foreseeable future.
Dendrobium guamense (no common name (NCN)), an epiphyte and
occasional lithophyte in the orchid family (Orchidaceae), is known from
the forest ecosystem on Guam, Rota, Saipan (historically), and Tinian,
and was recently recorded for the first time on Aguiguan (Ames 1914, p.
14; Raulerson and Rinehart 1992, p. 98; Quinata 1994, in litt.;
Raulerson 2006, in litt.; Costion and Lorence 2012, p. 66; Zarones et
al. 2015a, in litt.; Zarones et al. 2015c, in litt.). Raulerson (2006,
in litt.) cites D. guamense as also occurring on Agrihan, however, a
voucher record or survey report to support this location could not be
found. As recently as the 1980s, this species was common in trees on
Guam and Rota, with more than 12 occurrences on Guam and 17 occurrences
on Rota (Raulerson and Rinehart 1992, p. 98; Consortium Pacific
Herbarium (CPH) 2012a--Online Herbarium Database, 5 pp.).
Currently, there are at least 21 occurrences totaling approximately
1,250 individuals distributed on the islands of Guam, Rota, Tinian, and
Aguiguan; this is more than twice as many individuals as were known at
the time of the proposed rule. On Guam, there are 4 occurrences
totaling fewer than 250 individuals (Quinata et al. 1994, p. 8;
Harrington et al. 2012, in litt). On Rota, at least 15 occurrences of
D. guamense are now known, and a recent survey team reported more than
700 individuals of D. guamense on the western third of Rota,
represented by seedlings, juveniles, and flowering adults (Harrington
et al. 2012, in litt.; Zarones et al. 2015c, in litt.). The presence of
multiple generations in a healthy population structure indicates that
the status of D. guamense on Rota is better than previously known. This
survey team indicated that D. guamense is abundant across its preferred
habitat on Rota, and subsequently suggested that the actual number of
individuals could be as high as 35,000 (Zarones et al. 2015c, in
litt.). The Service supports the finding that the number of D. guamense
individuals on Rota is in the thousands, although we do not agree that
it is reasonable to assume the species is evenly distributed across the
island. However, this species is the most abundant of the three
epiphytic orchids listed as threatened species in this final rule.
Additionally, Zarones et al. (2015a, in litt.) discovered three
individuals of D. guamense on the island of Aguiguan, a new island
record for this species. Zarones et al. (2015a, in litt.) hypothesize
that more individuals may be found on Aguiguan and other northern
islands within CNMI if more in-depth surveys were attempted. There are
two reported occurrences on the island of Tinian, with an unknown
number of individuals (Quinata 1994, in litt.; Raulerson 2006, in
litt.; CPH 2012a--Online Herbarium Database, 5 pp.). Historically, D.
guamense was also known from Saipan, in the forest ecosystem (Raulerson
1987, in litt.; Raulerson 2006, in litt.; CPH 2012a--Online Herbarium
Database, 5 pp.). Formerly relatively common on Guam, the remaining few
populations of D. guamense and habitat for population enhancement or
restoration on Guam is at risk; additionally, D. guamense occurrences
are limited to just a few individuals on Tinian and Aguiguan, with no
confirmed individuals on Saipan at this time. Dendrobium guamense
appears stable and healthy on Rota, however, Raulerson and Rinehart
(1992, p. 87) warned that, although the endemic orchids on Rota appear
abundant, they occupy specialized habitat that are in fact rare.
On all islands on which it is known to occur (historically or
present), D. guamense faces two or more of the following impacts:
Habitat loss and destruction from agriculture, urban
[[Page 59436]]
development, nonnative animals and plants, fire, and typhoons, combined
with herbivory by nonnative invertebrates such as slugs. We anticipate
the effects of climate change will further exacerbate many of these
threats in the future.
Eugenia bryanii (NCN), a perennial shrub in the Myrtle family
(Myrtaceae), is known only from Guam. Historically, E. bryanii occurred
on windy, exposed clifflines along the west and east coasts of the
island, and from along the Pigua River, in the forest ecosystem
(Costion and Lorence 2012, p. 82; Gutierrez 2012, in litt.). Currently,
E. bryanii is known from 5 occurrences totaling fewer than 420
individuals (Gutierrez 2014, in litt.). Populations of E. bryanii, a
single island endemic, are decreasing from initial numbers observed on
Guam, and these remaining small populations are at risk, due to
continued habitat loss and destruction from agriculture, urban
development, nonnative animals and plants, and typhoons, combined with
herbivory by deer. We anticipate the effects of climate change will
further exacerbate many of these threats in the future.
Hedyotis megalantha (pao dedu, pao doodu), a perennial herb in the
coffee family (Rubiaceae), is known only from the savanna ecosystem on
Guam. Historically, H. megalantha was reported solely from Guam;
however, because several herbarium records reported this species on
Rota and Saipan, we investigated other reports and taxonomic and
genetic analyses concerning the range of this species. We believe the
Rota and Saipan reports are misidentifications or herbarium errors of
one or more of the other Hedyotis species also found in the Mariana
Islands (Fosberg et al. 1993, pp. 63-79; CPH 2012b--Online Herbarium
Database; World Checklist of Select Plant Families (WCSP) 2012a--Online
Herbarium Database). Between 1911 and 1966, this species ranged from
the mid-central mountains and west coast of Guam, south to Mt. Lamlam
(Bishop Museum 2013--Online Herbarium Database).
Currently, H. megalantha is known from one large scattered
occurrence totaling fewer than 1,000 individuals on southern Guam
(Costion and Lorence 2012, pp. 54, 86; Gutierrez 2012, in litt.; Bishop
Museum 2013--Online Herbarium Database; Gutierrez 2013, in litt.).
Hedyotis megalantha typically occurs as lone individuals rather than in
patches or groups (Gutierrez 2013, in litt.). In sum, the single known
occurrence of H. megalantha, a single island endemic, is decreasing
from initial numbers observed on Guam, and the remaining individuals
are at continued risk due to ongoing habitat loss and destruction from
agriculture, urban development, nonnative animals and plants, fires,
and typhoons, combined with habitat destruction and direct damage by
recreational vehicles. We anticipate the effects of climate change will
further exacerbate many of these threats in the future.
Heritiera longipetiolata (ufa halumtanu, ufa halom tano; looking
glass tree), a tree in the hibiscus family (Malvaceae), is known only
from the Mariana Islands. A few herbarium records have cited H.
longipetiolata on Palau, Chuuk, Pohnpei, and the Eastern Caroline
Islands; however, upon a thorough review of the literature and
herbarium records, and conferring with local botanical experts, we
conclude that these few outlying occurrences are actually H.
littoralis, not H. longipetiolata (Stone 1970, pp. 23, 420-421;
Raulerson and Rinehart 1991, p. 94; Wiles 2012, in litt.; Center for
Plant Conservation 2010, in litt.; CPH 2012c--Online Herbarium
Database; Global Biodiversity Information Facility (GBIF) 2014--Online
Herbarium Database; Harrington et al. 2012, in litt.; Lorence 2013, in
litt.).
Historically, Heritiera longipetiolata is reported from Guam, Rota,
Saipan, and Tinian, in the forest ecosystem (Stone 1970, p. 420;
Raulerson and Rinehart 1991, p. 94; CPH 2012c--Online Herbarium
Database; GBIF 2014--Online Herbarium Database). By 1997, there were
about 1,000 individuals on Guam, several hundred on Tinian, and fewer
than 100 on Saipan, with no known remaining individuals on Rota at that
time (Wiles in International Union for Conservation of Nature (IUCN)
Red List 2014, in litt.). Currently, H. longipetiolata is known from 10
occurrences totaling approximately 200 individuals, on Guam, Saipan,
Tinian, and Rota, all within the forest ecosystem (M and E Pacific,
Inc., pp. 6, 8, 31, 78; Harrington et al. 2012, in litt; Grimm 2013, in
litt). On Guam, H. longipetiolata is presently known from 4
occurrences, totaling approximately 90 individuals; on Tinian, there
are between 30 and 40 individuals of H. longipetiolata, and possibly
more in adjacent forested areas (Spaulding 2013, in litt.; Williams
2013, in litt.; Spaulding 2015, in litt.); on Saipan, H. longipetiolata
is known from 3 occurrences, totaling at least 53 individuals, with
several hundred seedlings beneath the trees (Camacho and Micronesian
Environmental Services (MES) 2002, pp. 38-39); and on Rota, more recent
information indicates that there is at least one known individual of H.
longipetiolata (Cook 2010, in litt. cited in CNMI-DLNR 2015, in litt.).
Although Wiles stated that there is strong evidence that H.
longipetiolata is not regenerating, and that seedlings and seeds are
eaten by ungulates and crabs, this observation appears to have been
made on Guam where feral deer and feral pigs are abundant and have been
observed to eat seedlings of H. longipetiolata (Guam Comprehensive
Wildlife Conservation Strategy 2005, p. 117; Rogers 2012, in litt.;
Wiles in IUCN Red List 2014, in litt.). Heritiera longipetiolata is on
Guam's endangered species list, listed as Vulnerable on IUCN's Red List
of Threatened Species, and is also a species of concern for Guam's
Plant Extinction Prevention Program. With roughly 200 individuals
remaining across its range (Guam, Saipan, Tinian, and Rota), both
Heritiera longipetiolata and habitat for the recovery of this species
are at risk due to ongoing habitat loss and destruction from
agriculture, urban development, nonnative animals and plants, and
typhoons. We anticipate the effects of climate change will further
exacerbate many of these threats in the future. Herbivory by pigs and
deer, and habitat and direct destruction by military live-fire training
also negatively impact H. longipetiolata.
Maesa walkeri (NCN), a shrub or small tree in the primrose family
(Primulaceae), is found only in the Mariana Islands. Historically, M.
walkeri is known from the islands of Guam and Rota, within the forest
ecosystem (Fosberg and Sachet 1979, pp. 368-369; M and E Pacific, Inc.
1998, pp. 31, 79; Raulerson and Rinehart 1991, p. 67; Costion and
Lorence 2012, p. 84; CPH 2012d--Online Herbarium Database; GBIF 2012b--
Online Herbarium Database; Wagner et al. 2012--Flora of Micronesia).
Several voucher specimens (preserved and labeled representative whole
plants or plant parts, used to compare and correctly identify plant
species, usually kept as part of an herbarium collection) report M.
walkeri from the Carolinian Island of Pohnpei, but after careful review
of the best available data (cited above), we conclude that M. walkeri
is endemic to the Mariana Islands.
Historically, M. walkeri was known from at least 13 occurrences on
Guam and 9 occurrences on Rota (Bishop Museum 2014--Online Herbarium
Database). Currently, M. walkeri is known from 5 occurrences in the
forest ecosystem on Guam and Rota, totaling at least 686 individuals.
This is a significant increase over numbers of individuals that were
known at the time
[[Page 59437]]
of the proposed rule (estimated at fewer than 60). On Guam, there are
two individuals (M and E Pacific, Inc. 1998, pp. 31, 79; Grimm 2013, in
litt.); and on Rota, there are at least 684 individuals spread out
across the Sabana, with a healthy population structure consisting of
seedlings, juveniles, and adults (Harrington et al. 2012, in litt.;
Gawel 2013, in litt.; Liske-Clark et al. 2015, in litt.). The presence
of multiple generations of the species indicates that the status of M.
walkeri is much better on Rota than previously understood. The number
of individual Maesa walkeri plants on Rota has been estimated to be in
the thousands across the Sabana region in small canopy gaps amidst the
Pandanus forest and along the forest edge; however, this is assuming M.
walkeri is evenly distributed (Ulloa 2015, pers. comm. cited in Liske-
Clark et al. 2015, in litt.; Liske-Clark et al. 2015, in litt.).
The Service supports the conclusion that there may be several
thousand more individuals across the Sabana. The cumulative data
indicate that Maesa walkeri was once relatively abundant on Guam and
Rota, and has since declined substantially on Guam. The only healthy
extant population of M. walkeri remains on the Rota Sabana within a
very specialized niche habitat that is experiencing habitat loss and
degradation from nonnative animals (deer and rats) and plants, and
fire; and is at risk from impacts associated with typhoons and future
climate change (e.g., potential shift in range to accommodate changes
in temperature, precipitation, humidity, etc., until the range no
longer exists). Additionally, habitat on Guam that is essential for the
recovery of M. walkeri continues to be affected by ongoing habitat loss
and destruction from agriculture, urban development, nonnative animals
and plants, fires, and typhoons. The effects of future climate change
will likely exacerbate many of these impacts. Maesa walkeri is a
species of concern for Guam's Plant Extinction Prevention Program.
Nervilia jacksoniae (NCN), a small herb in the orchid family
(Orchidaceae), is found only in the Mariana Islands. Historically, N.
jacksoniae occurred on the islands of Guam and Rota, in the forest
ecosystem, and ranged from northern to southern Guam and on the Sabana
region of Rota (Rinehart and Fosberg 1991, pp. 81-85; Raulerson and
Rinehart 1992, p. 118; Costion and Lorence 2012, p. 67). Currently,
there are approximately 15 occurrences totaling at least 520
individuals on the islands of Guam and Rota, in the forest ecosystem
(Harrington et al. 2012, in litt.; Zarones et al. 2015d, in litt.). On
Guam, N. jacksoniae is known from 2 occurrences totaling fewer than 200
individuals (M and E Pacific, Inc. 1998, p. 58; Grimm 2012, in litt.;
McConnell 2012, pers. comm.). On Rota, N. jacksoniae is known from 13
scattered occurrences totaling at least 320 individuals in the forest
ecosystem (Rinehart and Fosberg 1991, pp. 81-85; Raulerson and Rinehart
1992, p. 118; Costion and Lorence 2012, p. 67; CPH 2012e--Online
Herbarium Database; GBIF 2012c--Online Herbarium Database; McConnell
2012, pers. comm.; Zarones et al. 2015d, in litt.).
Zarones et al. (2015d, in litt.) recently conducted a small survey
on Rota, reporting 167 individuals of N. jacksoniae along four
transects in just 1.5 hours, and estimated that there may be as many as
100,000 individuals distributed across the Pandanus forest on the Rota
Sabana. This estimate, however, appears to be based on the premise that
this species is uniformly distributed across area. There are also a few
scattered occurrences along the areas adjacent to the Sabana (Zarones
et al. 2015d, in litt.). Our records indicate that this species occurs
in a more patchy distribution, in specialized niche habitat (Harrington
et al. 2015, in litt.). Similarly, Falanruw et al. (1989, pp. 6-7)
noted variation in the distribution of native species across the
Sabana, referring to the observed variations in forest structure as
phases of limestone forest. However, we do concur that the number of N.
jacksoniae individuals is likely to be much higher than what has been
observed by field biologists on Rota in the past, as this species can
occur deep within forested areas in the Sabana region that are
difficult to access due to extremely rugged karst and thick Pandanus
forest. Thus, although exact numbers are not known, the best available
scientific data do indicate that N. jacksoniae is likely more abundant
than was understood at the time of the proposed rule. Nonetheless, the
habitat for N. jacksoniae in the Sabana region is experiencing habitat
destruction and modification by nonnative animals (i.e., Philippine
deer and rats) and plants, fire, and typhoons. Additionally, N.
jacksoniae is preyed upon by nonnative invertebrates such as slugs.
Data indicate that populations of N. jacksoniae are decreasing from
their initial abundance observed on Guam (Rinehart and Fosberg 1991, p.
84; Cook 2012, in litt.; Harrington et al. 2012, in litt.), primarily
due to habitat loss and destruction from agriculture and urban
development; in addition to nonnative animals (i.e., pigs, water
buffalo, Philippine deer, and brown treesnake) and plants, fires, and
typhoons, and predation by nonnative invertebrates such as slugs. We
anticipate the effects of climate change will further exacerbate many
of these threats in the future.
Phyllanthus saffordii (NCN), a woody shrub in the Phyllanthaceae
family, is historically known only from the southern part of Guam
within the savanna ecosystem. Several literature and database sources
report this species from the northern Mariana Islands (Costion and
Lorence 2012, pp. 82-83; Wagner 2012--Flora of Micronesia; U.S.
Department of Agriculture--Agriculture Research Service--Germplasm
Resources Information Network (USDA-ARS-GRIN) 2013--Online Database;
WCSP 2012b--Online Database); however, a thorough review of the
literature, databases, and herbaria records revealed recorded
occurrences only on Guam (Merrill 1914, pp. 104-105; Glassman 1948, p.
181; Stone 1970, pp. 387-388; Pratt 2011, p. 59; Gutierrez 2012, in
litt.; GBIF 2012d--Online Herbarium Database; Bishop Museum 2013--
Online Herbarium Database; Smithsonian Institution 2014--Flora of
Micronesia Database). Until the early 1980s, P. saffordii ranged from
central to southern Guam (Bishop Museum 2014--Herbarium Database).
Currently, P. saffordii is known from 4 scattered occurrences on
southern Guam, totaling fewer than 1,400 individuals (Gutierrez 2013,
in litt.; Gawel et al. 2013, in litt.). Populations of P. saffordii, a
single island endemic, are thus decreasing from initial numbers
observed on Guam, and are at risk, due to continued habitat loss and
destruction from agriculture, urban development, nonnative animals and
plants, fires, and typhoons, combined with habitat destruction and
direct damage by recreational vehicles. We anticipate the effects of
climate change will further exacerbate many of these threats in the
future.
Psychotria malaspinae (aplokating palaoan), a shrub or small tree
in the coffee family (Rubiaceae), is known only from Guam.
Historically, P. malaspinae was known from scattered occurrences on the
northeast and southwest sides of Guam, in the forest ecosystem (Merrill
1914, pp. 148-149; Stone 1970, pp. 554-555; Raulerson and Rinehart
1991, p. 83; Fosberg et al. 1993, pp. 111-112; Costion and Lorence
2012, pp. 54, 85-86; Bishop Museum 2014--Online Database; Wagner 2012--
Flora of Micronesia; WCSP 2012c--Online Database). Currently, P.
malaspinae is known from only four occurrences, three with only a
single individual each (M and E Pacific, Inc. 1998, pp. 67, 79; Grimm
2012, in litt.), none of which
[[Page 59438]]
have been observed for at least 5 years; and a fourth recently
discovered occurrence with three individuals (Guam Plant Extinction
Prevention Program 2015, in litt.). Biologists searched for this
species during rare plant surveys conducted in July 2012; however, none
of the occurrences reported prior to July 2012 were relocated
(Harrington et al. 2012, in litt.). The tentative specimen of P.
malaspinae collected from the Ritidian National Wildlife Refuge on Guam
in August 2013, cited in the proposed rule as pending identification,
turned out to be P. hombroniana--another rare endemic species that may
warrant conservation actions (Gawel et al. 2013, in litt.; Gawel 2015,
in litt.). Psychotria malaspinae is also a species of concern for
Guam's Plant Extinction Prevention Program.
In summary, the species Psychotria malaspinae, a single island
endemic, has been reduced to an estimated five individuals in the wild,
and possibly fewer since several of these individuals have not been
observed for several years, rendering this species vulnerable to
extinction. There are likely a few scattered individuals or small
occurrences such as that recently discovered; however, these remaining
individuals are at risk, due to continued habitat loss and destruction
from agriculture, urban development, nonnative animals and plants, and
typhoons. We anticipate the effects of climate change will further
exacerbate many of these threats in the future. Herbivory by pigs and
deer, damage by ordnance and live-fire training, combined with the
effects of low numbers of individuals, which results in loss of vigor
and genetic representation, and limits its ability to compete with
other species and adapt to changes in environmental conditions,
contribute to the decline of P. malaspinae.
Solanum guamense (Biringenas halumtanu, birengenas halom tano), a
small shrub in the nightshade family (Solanaceae), is known only from
the Mariana Islands (Merrill 1914, pp. 139-140; Stone 1970, p. 521;
Costion and Lorence 2012, p. 89). Historically, S. guamense was
reported from Guam, Rota, Saipan, Tinian, Asuncion, Guguan, and Maug
(Stone 1970, p. 521; GBIF 2012e--Online Database; Bishop Museum 2014--
Online Database). Currently, S. guamense is known from a single
occurrence of one individual on Guam, in the forest ecosystem (Perlman
and Wood 1994, pp. 135-136).
Once ranging across multiple islands, Solanum guamense is now
highly vulnerable to extinction, as there is only one known extant
individual of this species. There is a possibility that remaining
individuals of S. guamense may occur on Asuncion, Guguan, or Maug; or
any combination of these three islands, possibly even on Uracas, as
these four islands are designated Wildlife Conservation Areas (also
referred to as sanctuary islands) by the CNMI constitution (Article
IX[2]) (Williams et al. 2009, p. 3). This article states that no
hunting, habitation, nor introduction of any nonnative species is
allowed (2NMIAC Sec. 85-30.1 330) (Williams et al. 2009, p. 3).
Further, Maug, Asuncion, Guguan, and Uracas are not frequently visited
for scientific purposes due to their remoteness and the associated
logistical challenges of planning and cost. Solanum guamense, and
habitat for its recovery on Guam, Rota, Saipan, and Tinian, are at
risk, due to continued habitat loss and destruction from agriculture,
urban development, nonnative animals and plants, and typhoons. We
anticipate the effects of climate change will further exacerbate many
of these threats in the future. Herbivory by pigs and deer, combined
with the effects of low numbers of individuals, which results in loss
of vigor and genetic representation, and limits its ability to compete
with other species and adapt to changes in environmental conditions,
contribute to the decline of S. guamense.
Tabernaemontana rotensis (NCN), a small to medium-sized tree in the
dogbane family (Apocynaceae), is historically known from Guam and Rota,
in the forest ecosystem (University of Guam (UOG) 2007, p. 6). The
genus is widespread throughout tropical and subtropical regions. We
originally proposed to list T. rotensis in January of 2004 (69 FR 1560,
January 9, 2004); however, in April 2004 (69 FR 18499) we declined to
do so because an authoritative monographic work on the genus
incorporated this species into an expansive interpretation of the
widespread species T. pandacaqui. In 2011, a genetic study was
conducted on specimens from Rota, Guam, Asia, and the Pacific, to
determine if those individuals on the Mariana Islands are a
monophyletic lineage. The study determined that T. rotensis is a valid
species, distinct from the widespread T. pandacaqui (Reynaud 2012, 27
pp. + appendices).
In 2004, T. rotensis was known from 8 individuals on Rota, and at
least 250 individuals on Guam (69 FR 1560; January 9, 2004). In 2007,
more than 21,000 individuals were found throughout Andersen AFB on
Guam, with a population structure representing seedling, juveniles, and
reproductive, mature individuals (UOG 2007 p. 4). In 2014, the CNMI
DLNR completed a survey of all known locations of naturally occurring
and outplanted individuals of T. rotensis on Rota, and found nine
living naturally occurring individuals and one dead individual (CNMI
DLNR 2014, in litt.). These were spread across the western, southern,
and eastern parts of the island. Additionally, there are 30 surviving
outplanted individuals, ranging in size from 4 to 23 ft (1.3 to 7 m),
spread out across the island (J. Manglona, T. Reyes, R. Ulloa, pers.
comm. 2014 cited in CNMI DLNR 2014, in litt.). Therefore, the best
scientific data currently available indicate that on Guam, T. rotensis
is known from 6 occurrences totaling approximately 21,000 individuals
(M and E Pacific, Inc. 1998, p. 61; UOG 2007, pp. 32-42), and on Rota,
T. rotensis is known from 9 individuals (CNMI DLNR 2014, in litt.).
Despite the increased number of known individuals of
Tabernaemontana rotensis, populations of this species on Guam and Rota
are at risk due to continued habitat loss and destruction from
agriculture, urban development, nonnative animals and plants, fires,
and typhoons; combined with ordnance and live-fire training. We
anticipate the effects of climate change will further exacerbate many
of these threats in the future. The greatest concern regarding this
species is not of population size or structure, but the close proximity
of occurrences to an area that is likely to be developed according to
the proposed AFB and Navy base expansions (UOG 2007, p. 5; JGPO-NavFac
Pacific 2010a, 2010b; JGPO-NavFac Pacific 2014; JGPO-NavFac Pacific
2015; http://guambuildupeis.us/).
Tinospora homosepala (NCN), a vine in the moonseed family
(Menispermaceae), is historically known only from Guam (Merrill 1914,
p. 83; Stone 1970, pp. 27, 277; Costion and Lorence 2012, pp. 92-93).
Currently, T. homosepala is known from 3 occurrences totaling
approximately 30 individuals, in the forest ecosystem (Yoshioka 2008,
p. 15; Gawel et al. 2013, in litt.). There is discussion among
botanists as to whether or not T. homosepala is either the same as a
commonly occurring species found throughout Malaysia and the
Philippines or a variety of that species (T. glabra) (Costion and
Lorence 2012, pp. 92-93; Gawel et al. 2013, in litt.). Tinospora
homosepala differs from T. glabra in having equal-sized sepals (petal-
like structures of the calyx) as opposed to the outer sepals being much
smaller than inner sepals as in T. glabra
[[Page 59439]]
(Forman 1981, pp. 381, 417, and 419; Costion and Lorence 2012, p. 93).
While these discussions note that additional research on the
taxonomy of Tinospora homosepala is appropriate to address questions,
no changes to the currently accepted taxonomy have been proposed.
Though Forman (1981, p. 419) notes that if fruits of T. homosepala are
discovered and they are indistinguishable from T. glabra, it may be
preferable to reduce T. homosepala to subspecific rank under T. glabra.
It should also be noted that any future reduction in rank from full
species status to that of a subspecies or variety would not, in itself,
disqualify this taxon from protection under the Act. All known
individuals of T. homosepala on Guam are said to be males that
reproduce clonally (Yoshioka 2008, p. 15; Gawel et al. 2013, in litt.).
Clonal reproduction limits genetic diversity, reducing the ability of
the species to form new genetic combinations to fit changing
environmental conditions (Stebbins 1957, p. 352).
In summary, the species T. homosepala, a single island endemic, has
been reduced to roughly 30 individuals on Guam, and it is possible that
no female representatives of this species remain. These few remaining
individuals of the species are at risk of extinction, due to continued
habitat loss and destruction from nonnative animals and plants, and
typhoons, and by genetic limitations as a result of the possible loss
of potential sexual reproduction. We anticipate the effects of climate
change will further exacerbate many of these threats in the future.
Tuberolabium guamense (NCN) (Trachoma guamense is a synonym), an
epiphyte in the orchid family (Orchidaceae), is known only from the
Mariana Islands. Historically, T. guamense was reported from the
islands of Guam, Rota, Tinian, and Aguiguan (Raulerson and Rinehart
1992, p. 127; CPH 2012f--Online Herbarium Database; GBIF 2012f--Online
Database). The Royal Botanical Gardens at Kew's online database (WCSP
2012d--Online Database) describes the range for T. guamense as the
Mariana Islands and the Cook Islands; however, we were unable to
confirm this with herbarium specimens as there is not a single voucher
that cites the Cook Islands as a collection site (CPH 2012f--Online
Herbarium Database; GBIF 2012f--Online Database; Smithsonian
Institution 2014--Online Herbarium Database). In 1992, T. guamense was
found in ``trees and shrubs all over the island'' (Raulerson and
Rinehart 1992, p. 127), and the Consortium of Pacific Herbaria has
records of 22 collections from Guam, 5 collections from Rota, 15
collections from Tinian, and 3 collections from Aguiguan (CPH 2012f--
Online database).
Currently, T. guamense is known from seven occurrences: one
occurrence of one individual on Guam and six occurrences on Rota, in
the forest ecosystem (Gawel et al. 2013, in litt.; Harrington et al.
2012, in litt.; Zarones et al. 2015c, in litt.). It is possible that a
few more individuals are scattered across native forests on Guam. The
number of occurrences on Rota represents an increase over those known
at the time of the proposed rule. A recent survey on Rota (Zarones et
al. 2015c, in litt.) reported finding 239 individuals of Tuberolabium
guamense along 6 of 18 transects surveyed on the Sabana, with a healthy
population structure consisting of seedlings, juveniles, and flowering
adults. Zarones et al. (2015c, in litt.) estimate that the actual
number of T. guamense individuals on the Sabana may be as high as
14,600; however, this appears to assume that T. guamense is evenly
distributed across the Sabana region. The Service does not concur that
this species is evenly or uniformly distributed across the Sabana,
consequently we conclude that 14,600 individuals is likely an
overestimate. For example, a particularly noteworthy observation from
these recent surveys is that T. guamense seems to occur solely in
native canopy trees, with the majority of individuals found on
Hernandia labyrinthica, Premna obtusifolia, and Elaeocarpus joga
(Zarones et al. 2015c, in litt.). As these native canopy trees are not
distributed uniformly across the landscape, neither would we expect T.
guamense to be evenly or continuously distributed across the Sabana.
However, we do agree that the survey results of Zarones et al. (2015c,
in litt.) indicate that the species Tuberolabium guamense is currently
more abundant on Rota than previously known.
In summary, populations of Tuberolabium guamense are decreasing
from their initial abundance observed on Guam, and although new data
show a higher number of T. guamense individuals than previously thought
on Rota, T. guamense still occupies very specialized niche habitat in
the Sabana region. More than 20 years ago, Raulerson and Rinehart
(1992, p. 87) stated that although the orchids may appear abundant on
the limestone ridges of Guam and Rota, ``the habitats are limited and
in reality these orchids are very rare.'' Additionally, they wrote,
``The islands are small and habitats are rapidly being destroyed by
human activity'' (Raulerson and Rinehart 1992, p. 87). Although numbers
of T. guamense are estimated to be possibly in the thousands on Rota
(Zarones et al. 2015c, in litt.), because of the specialized niche
habitat occupied by this species we are not in full agreement with this
estimate, which relies on an assumption of uniform distribution.
Furthermore, habitat for the recovery of this species is considered at
risk across its range. The remaining representatives of this species
and its habitat are vulnerable to ongoing threats posed by the
continued habitat loss and destruction from agriculture, urban
development, nonnative animals and plants, fires, typhoons, and
herbivory by slugs. We anticipate the effects of climate change will
further exacerbate many of these threats in the future.
Animals
Pacific Sheath-Tailed Bat (Mariana Subspecies)
The Mariana subspecies of the Pacific sheath-tailed bat
(Emballonura semicaudata rotensis) (payeyi, paischeey) is a small,
insectivorous (insect-feeding), sac-winged bat in the family
Emballonuridae, an old-world group with an extensive tropical
distribution. It is a relatively small bat species with an approximate
forearm length of about 1.8 in (45 mm) long. Males weigh 0.2 ounces
(oz.) (5.5 grams (g)) on average, and females weigh about 0.24 oz. (6.9
g) (Wiles et al. 2011, p. 303). The pelage varies in color from brown
to dark brown dorsally with a paler underbody (Walker and Paradiso
1983, p. 211). The common name ``sheath-tailed'' bat refers to the
nature of the tail attachment, which involves a short, narrow tail
emerging from a more anterior sheath-like membrane (Walker and Paradiso
1983, p. 209).
Taxonomically, four subspecies of Pacific sheath-tailed bats are
currently recognized: Emballonura semicaudata rotensis, endemic to the
Mariana Islands (Guam and the CNMI, referred to here as the Mariana
subspecies); E. s. sulcata in Chuuk and Pohnpei (Pohnpei subspecies);
E. s. palauensis in Palau (Palau subspecies); and E. s. semicaudata in
American and Independent Samoa, Tonga, Fiji, and Vanuatu (South Pacific
subspecies) (Koopman 1997, pp. 358-360; Oyler-McCance et al. 2013, pp.
1,030-1,036). Recent genetic analysis conducted by Oyler-McCance et al.
(2013, p. 1,030) found notable genetic differences between E. s.
rotensis, E. s. palauensis, and E. s. semicaudata; the magnitude of
these differences was greater than what is typically reported between
[[Page 59440]]
mammalian subspecies. In addition to divergence from the other three
subspecies, which would argue against reintroduction efforts based on
translocations of individuals between subspecific localities, the study
found no genetic variation between the 12 E. s. rotensis individuals
collected and examined (Oyler-McCance et al., 2013, p. 1,035), which
increases the risks associated with small number of individuals and
populations.
Once common and widespread throughout Polynesia and Micronesia, the
Pacific sheath-tailed bat, represented by the four subspecies, is the
only insectivorous bat recorded from a large part of this area (Hutson
et al. 2001, p. 138; Gorresen et al. 2009, p. 331; Wiles et al.. 2011,
p. 299; Oyler-McCance et al. 2013, p. 1,030; Valdez et al. 2013, p.
301). In the Caroline Islands, large numbers of individuals of the
sheath-tailed bat subspecies Emballonura semicaudata palauensis were
readily observed by Wiles et al. during studies in the 1990s (1997, p.
224). However, the other three subspecies of the bat have declined
dramatically, including in Independent and American Samoa and Fiji
(Bruner and Pratt 1979, p. 3; Grant et al. 1994, pp. 133-134; Wiles et
al. 1997, pp. 222-223; Wiles and Worthington 2002, pp. 17-19). In
American Samoa, a decrease in populations of the sheath-tailed bat
subspecies E. s. semicaudata was noted as early as the 1970s (Grant et
al. 1994, pp. 133-134). Researchers have identified several possible
factors for the past and ongoing decline of the Pacific sheath-tailed
bat throughout its range, including human disturbance of caves for
guano mining and shelter during World War II, bombing and shelling
during World War II, indiscriminate use of pesticides, predation by
monitor lizards, rats, and brown treesnakes, increasingly isolated
populations, and loss of foraging habitat due to human conversion and
destruction and alteration by typhoons and nonnative plants and animals
(Gorresen et al. 2009, p. 339; Valdez et al. 2011, p. 302; Wiles et al.
2011, pp. 306-307; and Oyler-McCance et al. 2013, p. 1,035).
In the Mariana Islands, fossil evidence indicates the Mariana
subspecies (Emballonura semicaudata rotensis) (hereafter simply
referred to as the Pacific sheath-tailed bat or simply ``bat,'' unless
noted otherwise), was common on both Guam and Rota, and somewhat less
common on the island of Tinian (Steadman 1999, p. 321; Wiles and
Worthington 2002, pp. 1-3; Wiles et al. 2011, p. 299). Historically,
populations of the Pacific sheath-tailed bat were reported from Saipan
(Wiles et al. 2011, p. 299), and possibly on Anatahan and Maug as well
(Lemke 1986, pp. 743-745). The Mariana subspecies of the Pacific
sheath-tailed bat is now restricted to a single remaining population on
the small (2.7 square-mile (sq mi; 7 square-kilometer (sq km)) island
of Aguiguan, where it was first observed in 1984 (Wiles et al. 2011, p.
299). The bat has clearly experienced a precipitous reduction from its
wider historical range in the Mariana Islands (formerly Guam, Rota,
Saipan, Tinian, and Aguiguan), which can reasonably be assumed to be
coincident with a significant decline in abundance of individuals.
Currently, the Aguiguan bat population consists of several roosting
colonies estimated to number between 359 to 466 individuals (Wiles and
Worthington 2002, p. 15; Wiles 2007, pers. comm.; O'Shea and Valdez
2009, pp. 2-3; Wiles et al. 2011, p. 299; Oyler-McCance et al. 2013, p.
1,030). During several field surveys between 1995 and 2008, Wiles et
al. (2011, pp. 299-305), examined a total of 114 caves on the island,
of which approximately 8 caves contained roosting bats, with 4 caves
consistently occupied during the 13-year study period. Colonies ranged
in size from 333 bats in the largest colony, to between 1 and 64 one
bats in the other colonies (Wiles et al. 2011, pp. 301-303).
Despite observed declines in populations of most Pacific sheath-
tailed bat subspecies elsewhere, as well as with the Marianas
subspecies in general across the Marianas Archipelago, researchers have
recorded a small increase in the observed number of bats on Aguiguan in
past years, starting with 98 individuals in 1995, up to 285 to 364 bats
in 2003, and 359 to 466 bats in 2008 (Wiles et al. 2011, p. 304). The
researchers used population growth models to ensure that this apparent
increase is biologically plausible, as opposed to a potential artifact
of variable survey methods; they conclude that the increase is most
likely real, while cautioning that additional data and analysis are
needed. They also suggest that the single remaining population of the
Mariana subspecies of Pacific sheath-tailed bat on Aguiguan is more
likely limited by foraging habitat, and not by roosting habitat (Wiles
et al. 2011, pp. 304-305). Although this very small population on the
tiny island of Aguiguan appears to be relatively healthy, it has
limited foraging habitat, which is threatened by feral goats, nonnative
plants, development, and typhoons; and the bats are at risk from
predation by rats, monitor lizards, and brown treesnakes.
Breeding of Pacific sheath-tailed bats is timed to coincide with
offspring born during the onset of the rainy season when there are
predictably greater numbers of insect prey. Pacific sheath-tailed bat
females produce one pup per litter annually, which translates into
relatively low fecundity for the species (Wiles et al. 2011, p. 303).
The bats are nocturnal and roost during the day in a wide range of
cave-types, including overhanging cliffs, limestone solution caves,
crevices, and lava tubes, (Grant et al. 1994, pp. 134-135; O'Shea and
Valdez 2009, pp. 105-108), and emerge shortly before sunset to forage
on insects (Craig et al. 1993, p. 51; Wiles and Worthington 2002, p.
13; Wiles et al. 2011, pp. 301-303). Unlike the Pohnpei subspecies,
which utilizes hollow trees for roosting (Wiles et al. 2011, p. 305),
the Mariana subspecies of the Pacific sheath-tailed bat appears to be
cave-dependent on Aguiguan, which has approximately 114 caves of
various sizes classified from small to large (Wiles et al. 2011, pp.
301-302). On the Northern Mariana Islands, which contain far fewer
caves due to their relatively young geologic age and volcanic origin,
it is possible that the presence of the predatory monitor lizard may
preclude the use of hollow trees as roosting sites by the Pacific
sheath-tailed bat (Wiles 2011, p. 306).
The Pacific sheath-tailed bat is also known to share roosting caves
with Mariana swiftlets (birds, Aerodramus spp.) (Lemke 1986, pp. 744-
745; Tarburton 2002, pp. 106-107; and Wiles and Worthington 2002, pp.
7, 13; Wiles et al. 2011, p. 302). During several field studies between
1995 and 2008, Wiles et al. (2011, pp. 302-303), observed Mariana
swiftlets roosting in seven out of eight caves co-occupied by the bat,
albeit within somewhat segregated portions of the cave. In the same
1995-2008 study, Wiles et al. (2011, p. 302) also determined that bats
on Aguiguan prefer caves characterized as ``large'' (over 1,076 ft\2\
(100 m\2\) in floor area with ceiling heights reaching 16 to 98 ft (5
to 30 m)) (see ``Cave Ecosystem,'' in the proposed rule (79 FR 59364;
October 1, 2014), for further cave description). Researchers also found
occupied caves to be fairly constant in both temperature and humidity,
with conditions homogenous and consistent between occupied caves,
including most seemingly suitable, unoccupied caves (Wiles et al. 2011,
p. 305).
Some information about the Pacific sheath-tailed bat's biology and
life history, including reproduction, habitat use, diet, and limiting
factors, has been historically difficult to observe and collect due to
a variety of factors
[[Page 59441]]
including the bat's small size, secretive habits, difficulty of
capture, non-specific roosting sites, and--following its extirpation
from most of the islands in its range in the Marianas--the remoteness
of the sole remaining population (Wiles and Worthington 2002, p. 19;
Esselstyn et al. 2004, p. 304; Wiles et al. 2011, p. 305). Funded by
the Department of the Navy and the Service, more recent studies
including Gorresen et al. 2009 (pp. 331-340), O'Shea and Valdez 2009
(pp. 95-97), Valdez et al. 2011 (pp. 301-309), Wiles et al. 2011 (pp.
299-309), and Oyler-McCance et al. 2013 (pp. 1,030-1,036), have
provided us with new information about the species. For example, we now
know from fecal pellets collected from caves on Aguiguan that Pacific
sheath-tailed bats there consume a diverse array of small-sized (0.078-
0.314 in (2-8 mm)) insects, including ants, bees, and wasps
(Hymenoptera), moths (Lepidoptera), and beetles (Coleoptera), as their
primary prey (O'Shea and Valdez 2009, pp. 63-65; Valdez et al. 2011,
pp. 301-307).
Earlier surveys of habitat use on Aguiguan in 2003 revealed that
the Pacific sheath-tailed bat forages almost entirely in native and
nonnative forests near their roosting caves, ignoring non-forested
habitats on the island (Esselstyn et al. 2004, p. 307). Outside of the
Mariana Islands, Bruner and Pratt (1979, p. 3) observed similar
behavior, with the other subspecies of Pacific sheath-tailed bats
(Emballonura semicaudata semicaudata, E. s. sulcata, and E. s.
palauensis) foraging only in native forests. New evidence from recent
studies appears to confirm prior observations regarding the association
between bat foraging and native limestone forest. For example, the
aforementioned dietary study by Valdez et al. 2011 (pp. 301-307),
showed that the bat feeds on certain insects, including barklice
(Pscoptera) and fungus-feeding beetles, each very specific to forest
habitat on Aguiguan. A 2008 study analyzed the bat's specific method of
echolocation (use of sonar to navigate) and flight pattern, both of
which are similar to other insect-eating, forest-foraging bats, to
identify a correlation between foraging activity and roosting site
proximity to native forest canopy and the height and nature of that
forest canopy (O'Shea and Valdez 2009, pp. 105-108; Gorresen et al.
2009, p. 331). The Gorresen et al. study (2009, p. 336) as well as
Wiles et al. (2011 p. 305), point to the high number of unoccupied
caves on Aguiguan and suggest it is likely the amount of native forest
cover, not the number of suitable roost sites, that may be the main
factor currently limiting the island's Pacific sheath-tailed bat
population. Some researchers go further to point out that insectivorous
bats relying on forested areas for foraging are at greater risk of
extinction than those which employ a wider range of foraging methods
(Gorresen et al. 2009, p. 339). Researchers familiar with the status of
the Pacific sheath-tailed bat readily identify an almost complete lack
of native forest regeneration on Aguiguan and the ever-present
possibility of forest destruction by hurricanes as two factors
threatening the species' continued existence in the Mariana Islands
(Gorresen et al. 2009, p. 339; Wiles et al. 2011, pp. 306-307).
In summary, the Mariana subspecies of the Pacific sheath-tailed bat
(Emballonura semicaudata rotensis), now reduced to a single, remaining
population on Aguiguan, has shown a clear and significant decline from
its original wide range across at least four, and possibly as many as
six, of the Mariana Islands. With recent research suggesting inter-
genetic homogeneity within its own population, we now understand that
the Mariana Islands Pacific sheath-tailed bat is at especially great
risk due to its small population size and isolation from other
subspecies. Despite the small increases in abundance of the sole
remaining population noted in recent years, the Mariana subspecies of
the Pacific sheath-tailed bat faces threats of continued habitat loss
and destruction. Additionally, predation by monitor lizards, and
potential predation by the brown treesnake, may contribute to the
further decline of the species.
Slevin's Skink
Slevin's skink (Emoia slevini, gualiik halumtanu, gh[oacute]luuf)
is a small lizard in the reptile family Scincidae, the largest lizard
family in number of worldwide species. Slevin's skink was first
described in 1972 by Walter C. Brown and Marjorie V.C. Falanruw, which
is the most recent and accepted taxonomy (Brown and Falanruw 1972, p.
107). It is the only lizard endemic to the Mariana Islands and is on
the Government of Guam's Endangered Species List (Fritts and Rodda
1993, p. 3; Rodda et al. 1997, p. 568; Rodda 2002, p. 2; CNMI Division
of Fish and Wildlife (DFW) 2005, p. 174; GDAWR 2006, p. 107; Guam
Department of Agriculture 2014, in litt.). Slevin's skink previously
occurred on the southern Mariana Islands (Guam, Cocos Island, Rota,
Tinian, and Aguiguan), where it is now extirpated, except from Cocos
Island off Guam, where it was recently rediscovered (Fritts and Rodda
1993, p. 2; Steadman 1999; Lardner 2013, in litt.). Local skink experts
hypothesize that the individuals on Cocos Island may be a distinct
species or subspecies from Slevin's skinks in the northern islands, and
are currently conducting a genetic analysis to determine the taxonomic
status (Reed 2015, in litt.).
Surveys conducted in the 1980s and 1990s show that Slevin's skink
was once present on the northern islands of Sarigan, Guguan, Alamagan,
Pagan, and Asuncion (Vogt 1997, in litt.; Berger et al. 2005, pp. 174-
175; GDAWR 2006, p. 107); however, none were captured on Anatahan or
Agrihan or ever reported historically from these islands (Rodda et al.
1991, p. 202; Berger et al. 2005, p. 175). The skink has not yet been
reported from the southern island of Saipan, or the northern islands of
Farallon de Medinilla, Maug, or Uracas. The densest population was on
Alamagan (island area of 2,800 ac; 1,130 ha) in the early 1990s, but
researchers believe that overgrazing by introduced ungulates may
preclude the long-term viability of that population (Fritts and Rodda
1993, p. 1; Rodda 2002, pp. 1-3). The most recent surveys of Alamagan
were completed in 2000. Based on their survey efforts, Cruz et al.
(2000, pp. 24, 26) reported a capture rate of approximately 0.019
Slevin's skinks per trap hour for Alamagan, which was lower than the
capture rate of 0.033 per trap hour reported by McCoid et al. (1995, as
cited in Cruz et al. 2000, p. 24) 5 years earlier. The authors state
that this may be indicative of a decline in the population of Slevin's
skink on the island, but also note that it may be due to seasonal
fluctuations (sampling was limited to only 2 nights at a single
location in June 2000); they conclude that more surveys are needed
(Cruz et al. 2000, p. 26).
After the eradication of feral ungulates from the island of Sarigan
in 1998, the catch rate of skinks (number of lizards captured per hour)
roughly quadrupled in a survey conducted in 2007 (Vogt 2007, p. 5-5;
Kessler 2011, p. 322), which indicates the skinks are doing much better
on Sarigan and that ungulates played a role in their prior decline.
Numbers of Slevin's skinks trapped on Asuncion in surveys conducted in
2008 were quite low; only 3 individuals were captured following 350
hours of effort at 20 trap stations, translating to 0.008 per trap hour
(Williams et al. 2008, pp. 36). Recent intensive surveys on Pagan
conducted in 2010 by Reed et al. (2010, pp. 22, 27) found no Slevin's
skinks, leading some experts to postulate that Slevin's skink may be
potentially extirpated on Pagan,
[[Page 59442]]
if not certainly rare, but ultimately concluding that it is too early
to make a definitive judgment (Rodda 2014, in litt.). The current
status of Slevin's skink on Guguan is unknown.
Slevin's skink measures 3 in (77 mm) from snout to cloaca vent (the
opening for reproductive and excretory ducts), although length can vary
slightly (Vogt and Williams 2004, p. 65). Fossil remains indicate its
prehistoric size was much larger, up to 4.3 in (110 mm) in length
(Rodda 2010, p. 3). Slevin's skink is darkly colored, from olive to
brown, with darker flecks in a checkerboard pattern, and a light orange
to bright yellow underside (Vogt and Williams 2004, p. 65). Their skin
tends to be shiny, and is very durable and tough. Juveniles may appear
cream-colored (Vogt and Williams 2004, p. 65; Rodda 2010, p. 3).
Slevin's skink is a fast-moving, alert, insectivorous lizard,
typically found on the ground or at ground level, and is active during
the day. The species occurs in the forest ecosystem, with most
individuals observed on the forest floor using leaf litter as cover
(Brown and Falanruw 1972, p. 110; Cruz et al. 2000, p. 21; GDAWR 2006,
p. 107; Lardner 2013, in litt.). Occasionally, individuals were
observed in low hollows of tree trunks (Brown and Falanruw 1972, p.
110). It is a social species, seen often in the company of other
individuals, including other nonnative skink species (Vogt and Williams
2004, pp. 59, 65). The females are oviparous, with a normal clutch size
of two (Zug 2013, p. 184; Rodda 2014, in litt.). Other specific life-
history or habitat requirements of Slevin's skink are not well
documented (Rodda 2002, p. 3; Zug 2013, p. 184).
Slevin's skink was most numerous in the Mariana Islands before the
introduction of other competing lizards and predators, and loss of
native forest (Vogt and Williams 2004, p. 65; Berger et al. 2005, p.
175). After World War II, Slevin's skink had notably vanished from the
larger southern Mariana Islands (Fritts and Rodda 1993, p. 4), which
suggests the species may be sensitive to habitat destruction or changes
in land use practices (Fritts and Rodda 1993, p. 4; Berger et al. 2005,
p. 174). Likewise, as noted above, the observed four-fold increase in
captures of Slevin's skink on Sarigan following the removal of
nonnative ungulates from that island (Vogt 2007, p. 5-5; Kessler 2011,
p. 322) indicates that nonnative ungulates have a negative impact on
the species. Slevin's skink had not been recorded on Guam since 1945
and had not been observed on Cocos Island since the early 1990s (Rodda
and Fritts 1992, p. 171; Campbell 2011, in litt.), until a specimen was
captured on Cocos Island in January of 2011 (following eradication of
rats from that island; Campbell 2011, pers. comm.). Over half of Cocos
Island is developed for a hotel, and it is a tourist destination
(Fritts and Rodda 1993, p. 2). Only about 25 ac (10 ha) of suitable
habitat for Slevin's skink is available on Cocos Island, and this is
periodically overwashed during typhoons (Fritts and Rodda 1993, pp. 2,
5), thus there is little if any stable suitable habitat permanently
available on the island.
The northern islands of its known occurrence provide less than
19,843 ac (8,030 ha) of land area, not all of which is suitable
habitat. Slevin's skink is no longer found on the larger southern
islands of Guam, Rota, and Tinian, which, combined, provided the great
majority of its formerly occupied range, totaling an estimated 179,900
ac (72,800 ha). Even without considering its potential recent
extirpation from Pagan, based on these numbers it is apparent that
Slevin's skink has likely been reduced to just 10 percent of its
overall historical range, and its remaining suitable habitat is a
subset of that area.
In summary, once widespread, the remaining known populations of
Slevin's skink are made up of a few individuals on Cocos Island, where
habitat is limited and subject to overwashing, and occurrences of
undetermined numbers of individuals on Alamagan, Guguan, Sarigan, and
Asuncion. Slevin's skink persists in low numbers observed on Cocos
Island, is possibly extirpated from Pagan, and has not been reobserved
on Guam, Rota, Tinian, or Aguiguan. Of the nine islands from which it
was formerly known, Slevin's skink is known to be recovering to some
degree from the effects of past threats (nonnative ungulates) only on
the island of Sarigan; however, other threats remain on this island
(e.g., rats). Overall, Slevin's skink has been lost from 90 percent of
its former range. Because populations are reduced in distribution and
likely small, we conclude the remaining populations of Slevin's skink
are at risk, due to continued habitat loss and destruction from
agriculture, development, nonnative animals (feral pigs, cows, and
goats), and typhoons. We anticipate the effects of future climate
change will further exacerbate many of these threats in the future.
Predation by rats, monitor lizards, and possible predation by the brown
treesnake (if the snake is introduced to other islands), also pose
ongoing threats to Slevin's skink.
Mariana Eight-Spot Butterfly
The Mariana eight-spot butterfly (Hypolimnas octocula marianensis)
(abbabang, libweibwogh), a butterfly in the Nymphalidae family, is
known solely from the islands of Guam and Saipan, in the forest
ecosystem (Schreiner and Nafus 1996, p. 2; Schreiner and Nafus 1997, p.
26). It may be extirpated from Saipan (Schreiner and Nafus 1997, p.
26). This subspecies was originally described by Butler and is
recognized as a distinct taxon in Swezey (1942, p. 35), the most recent
and accepted taxonomy for this species. Like most nymphalid
butterflies, orange and black are the two primary colors exhibited by
this subspecies. The males are smaller than the females by at least a
third or more in size. Males are predominantly black with an orange
stripe running vertically on each wing. The stripe on the hindwings
exhibits small black dots in a vertical row. Overall, the females
appear more orange in color than the males, and black bands across the
apical (top) margins of both pair of wings are exhibited. Along the
inner margin of these black bands, large white spots are exhibited
across the entire length of the wings (Schreiner and Nafus 1997, pp.
15, 26-27). The caterpillar larva of this species is black in color
with red spikes and a black head, differentiating it from similar-
appearing caterpillars including Hypolimnas bolina and H. anomala
(Schreiner and Nafus 1996, p. 10; Schreiner and Nafus 1997, p. 26).
The larvae of this butterfly feed on two native plants, Procris
pedunculata (no common name) and Elatostema calcareum (tapun ayuyu)
(Schreiner and Nafus, 1996, p. 1). Both of these forest herbs (family
Urticaceae) are found only on karst substrate within the forest
ecosystem, draped over boulders and small cliffs (Schreiner and Nafus
1996, p. 1; Rubinoff 2013, in litt.). Surveys show that these two host
plants are no longer observed in places where nonnative ungulates can
reach them easily, and in the rare case that a plant grows long enough
to extend beyond the protection of the extremely rugged limestone
karst, browsing damage is observed (Rubinoff 2013, in litt.; Lindstrom
and Benedict 2014, pp. 29, 32-35; Rubinoff 2014, in litt.). The
eradication of ungulates would allow these host plants to expand their
range onto less rugged karst, consequently increasing their
availability for the Mariana eight-spot butterfly. When adult
butterflies were observed, they were always in proximity to the host
plants (Rubinoff 2011, in litt.; Rubinoff 2013, p. 1). The two host
plants have
[[Page 59443]]
been recorded on the islands of Guam, Rota, Saipan, and Tinian
(Schreiner and Nafus 1996, p. 2; Schreiner and Nafus 1997, p. 26;
Harrington et al. 2012, in litt.; Rubinoff and Haines 2012, in litt.;
Rubinoff, in litt. 2013). However, despite recent surveys (2011-2013)
on Rota, Tinian, and Saipan, the Mariana eight-spot butterfly is
currently known only from the island of Guam (Schreiner and Nafus 1996,
p. 2; Schreiner and Nafus 1997, p. 26; Rubinoff and Haines 2012, in
litt.; Rubinoff 2013, in litt.).
Recent surveys conducted across Guam confirmed the occurrence of
the Mariana eight-spot butterfly in six areas on the island (Lindstrom
and Benedict 2014, p. 9). This survey report did not provide estimates
for the number of individuals per population. Lindstrom and Benedict
(2014, p. 9) stated that there are currently only 6 populations of this
species, not the 11 populations cited in the October 1, 2014, proposed
rule (79 FR 59364). We do not believe this difference reflects a
reduction in the number of populations since the publication of the
proposed rule, however. In part, this discrepancy in numbers may lie in
the definition of a ``current population.'' We distinguish populations
as separate if they are 3,280 ft (1,000 m) or more apart, and define
current as a report within 20 years from the present date. In addition,
although quite extensive, the surveys conducted by Lindstrom and
Benedict and colleagues (2014, pp. 1-44) did not survey all previously
cited current occurrences for the Mariana eight-spot butterfly on Guam
(Schreiner and Nafus 1996, p. 2; Schreiner and Nafus 1997, p. 26;
Rubinoff 2011, in litt.; Rubinoff and Haines 2012, in litt.; Rubinoff
2013, in litt.), so some may have been overlooked. Finally, a lack of
observation on select transects at previously reported sites does not
necessarily translate to a complete absence of the species at that
location; the lack of observation may be more indicative that the
species exists in very low numbers. Especially if the site is visited
only once, it is easy to miss an observation if individuals are quite
rare.
On Saipan, several areas were found that supported host plants in
2011 and 2012; however, no individuals of the Mariana eight-spot
butterfly were seen, and it may be extirpated on Saipan (Schreiner and
Nafus 1997, p. 26; Harrington et al. 2012, in litt., p. 19; Rubinoff
2014, in litt.). It is possible that small undetected populations of
the Mariana eight-spot butterfly still occur on islands previously
recorded (Lindstrom and Benedict 2014, p. 34), or even on the more
isolated northern islands on which it has not previously been recorded
(Rubinoff 2014, in litt.); however, without any evidence, this remains
postulation.
In summary, the Mariana eight-spot butterfly is now found in only
six populations on the island of Guam. This butterfly is dependent upon
two relatively rare host plant species, both of which are susceptible
to the effects of ungulate grazing. The Mariana eight-spot butterfly is
vulnerable to the impacts of continued habitat loss and destruction
from agriculture, urban development, nonnative animals and plants, and
typhoons. We anticipate the effects of climate change will further
exacerbate many of these threats in the future. Herbivory of its host
plants by nonnative animals, combined with direct predation by ants and
parasitic wasps, contribute to the decline of the Mariana eight-spot
butterfly.
Mariana Wandering Butterfly
The Mariana wandering butterfly (Vagrans egistina) (abbabang,
libweibwogh) is endemic to the islands of Guam and Rota in the Mariana
archipelago, in the forest ecosystem. This butterfly was originally
named Issoria egistina (Swezey 1942, p. 35). In 1934, Hemming published
the genus Vagrans as a replacement name for the genus Issoria.
Schreiner and Nafus (1997) recognize this species as Vagrans egistina,
which is the most recent and accepted taxonomy.
Like most nymphalid butterflies, the Mariana wandering butterfly is
primarily orange and black in coloration. This species is largely black
in appearance with a prominent orange irregular pattern extending from
the forewings to the hindwings. Obvious stripes or rows of spots are
lacking (Schreiner and Nafus 1997, plate 9). The caterpillar larva life
stage of this species is brown in color with black-colored spikes
(Schreiner and Nafus 1996, p. 10).
Mariana wandering butterflies are known to be good fliers, and in
earlier times, probably existed as a series of meta-populations
(Harrison et al. 1988, p. 360), with considerable movement and
interbreeding between local and stable populations and continued
colonization and extinction in disparate localities. The larvae of this
butterfly feed on the plant species Maytenus thompsonii (luluhut) in
the Celastraceae family, which is endemic to the Mariana Islands
(Swezey 1942, p. 35; Schreiner and Nafus 1996, p. 1). The host plant M.
thompsonii is known to occur within the forest ecosystem on Guam, Rota,
Saipan, and Tinian (Vogt and Williams 2004, p. 121).
Historically, the Mariana wandering butterfly was originally
collected and described from the island of Guam where it was considered
to be rare, but widespread (Swezey 1942, p. 35). The species has not
been observed on Guam since 1979, where it was last collected in Agana.
Currently, it is considered likely extirpated from Guam (Schreiner and
Nafus 1996, pp. 1-2; Rubinoff 2013, in litt.). The Mariana wandering
butterfly was first collected on Rota in the 1980s (Schreiner and Nafus
1996, p. 10). During several 1995 surveys on Rota, it was recorded at
only one location among six different sites surveyed (Schreiner and
Nafus 1996, pp. 1-2). From June through October 2008, extensive surveys
for the Mariana wandering butterfly were conducted on the island of
Tinian under the direction of the Service. While several Maytenus
thompsonii host plant population sites were identified in limestone
forest habitat, no life stages of the Mariana wandering butterfly were
observed (Hawley in litt., 2008, pp. 1-9). Despite extensive surveys on
Guam in 2013 for the Mariana wandering butterfly and several other
candidate species, no evidence (i.e., egg, larva, or adult) of the
Mariana wandering butterfly was found (Lindstrom and Benedict 2014, pp.
21-41).
Although considered extirpated from Guam, whether the Mariana
wandering butterfly continues to exist on Rota is unknown, since the
island has not been surveyed specifically for this butterfly since
1995. It is possible this species occurs on the northern islands where
host plants are found (Rubinoff 2014, in litt.), although there is no
record of its presence. Several years of seasonal surveys are needed to
determine the status of this species, but if it persists, it is likely
in very low numbers as it has not been observed in many years. Any
remaining populations of the Mariana wandering butterfly continue to be
at risk from ongoing habitat loss and destruction by rats and typhoons.
We anticipate the effects of climate change will further exacerbate
many of these threats in the future. Herbivory of its host plant by
nonnative animals, combined with direct predation by ants and parasitic
wasps, contribute to the decline of the Mariana wandering butterfly.
Rota Blue Damselfly
The Rota blue damselfly (Ischnura luta) (dulalas Luta, dulalas
Luuta) is a small damselfly endemic to the island of Rota and found
within the stream ecosystem. Grouped together with dragonflies in the
order Odonata, damselflies fall within the suborder
[[Page 59444]]
Zygoptera. The Rota blue damselfly belongs to the family
Coenagrionidae, and it is the only known damselfly species endemic to
the Mariana Islands. This species was first described in 2000 (Polhemus
et al. 2000, pp. 1-2) based upon specimens collected in 1996. The
species is relatively small in size, with males measuring 1.3 in (34
mm) in body length, with forewings and hindwings 0.7 in (18 mm) and
0.67 in (17 mm) in length, respectively. Both sexes are predominantly
blue in color, particularly the thorax and portions of the male's
abdomen are brilliant, iridescent blue. Both sexes have a yellow and
black head with some yellow coloration on the abdomen. Females of this
species may be distinguished by their slightly smaller size and
somewhat paler blue body color (Polhemus et al. 2000, pp. 1-8).
Resembling slender dragonflies, damselflies are readily
distinguished by their trait of folding their wings parallel to the
body while at rest rather than holding them out perpendicular to the
body. The general biology of narrow-winged damselflies includes
territorial males that guard areas of habitat where females will lay
eggs (Moore 1983a, p. 89; Polhemus and Asquith 1996, pp. 2-7). During
copulation, and often while the female lays eggs, the male grasps the
female behind the head with terminal abdominal appendages to guard the
female against rival males; thus males and females are frequently seen
flying in tandem. Adult damselflies are predaceous and feed on small
flying insects such as midges and other flies.
The immature larval life stages (naiads) of the vast majority of
damselfly species are aquatic, breathe through flattened abdominal
gills, and are predaceous, feeding on small aquatic invertebrates or
fish (Williams 1936, p. 303). Females lay eggs in submerged aquatic
vegetation or in mats of moss or algae on submerged rocks, and hatching
occurs in about 10 days (Williams 1936, pp. 303, 306, 318; Evenhuis et
al. 1995, p. 18). Naiads may take up to 4 months to mature (Williams
1936, p. 309), after which they crawl out of the water onto rocks or
vegetation to molt into winged adults, typically remaining close to the
aquatic habitat from which they emerged. Adults have been observed in
association only with the single perennial stream on Rota; therefore,
we believe the larval stage of the Rota blue damselfly is aquatic.
The Rota blue damselfly was first discovered in April 1996, when a
few individuals were observed and one male and one female specimen were
collected outside the Talakhaya Water Cave (also known as Sonson Water
Cave) located below the Sabana plateau (Camacho et al. 1997, p. 4;
Polhemus et al. 2000, pp. 1-8). The size of the population at the time
of discovery was estimated to be small and limited to the stream area
near the mouth of the cave. The primary source of the stream is spring
water emerging at the limestone-basalt interface below the highly
permeable limestone of the Sabana plateau (Polhemus et al. 2000, pp. 1-
8; Keel et al. 2011, p. 1). This spring also serves as the main source
of fresh water supply for the population of Rota (Polhemus et al. 2000,
pp. 1-8; Keel et al. 2011, p. 1). A concrete collection structure with
associated piping has been built into and surrounding the entrance of
the water cave. This catchment system and a smaller, adjacent catchment
deliver approximately 2.7 to 3.8 million liters-per-day (0.7 to 1
million gallons) of water to Rota's municipal system (Keel et al. 2011,
pp. 29-30) (see ``Stream Ecosystem,'' in the proposed rule (79 FR
59364; October 1, 2014), and Water Extraction under Factor E. Other
Natural or Manmade Factors Affecting Their Continued Existence, below,
for further discussion).
Eighteen years elapsed between the original discovery of the
species in 1996 and the next known survey for the Rota blue damselfly.
In January 2014, two male specimens were observed flying above a
portion of the stream located at approximately 770 ft (235 m) in
elevation, and below the Talakhaya (Sonson) Water Cave (Richardson
2014, in litt.). No specimens were observed immediately in the vicinity
of the water cave entrance, and no fish were observed in the stream
immediately below the cave entrance (Richardson 2014, in litt.). This
is a notable observation because many damselfly species endemic to
Pacific islands are known to be susceptible to predation by nonnative
fish species that eat the naiad life stage of the damselfly. In
November 2015, Zarones et al. (2015b, in litt.) conducted a survey on
Rota looking for the Rota blue damselfly and found one individual along
a stream 744 yards (680 m) to the west of Water Cave area, not
connected to the stream at the Water Cave. Zarones et al. (2015b, in
litt.) did not report whether or not any native or nonnative fish were
observed in the stream.
Predation by nonnative fish is a serious threat to the Hawaiian
Megalagrion damselfly naiads (Englund 1999, pp. 235-236). Eggs laid in
vegetation or on rocks in streams hatch in about 10 days and develop
into naiads. Naiads take approximately 4 months to mature before
emerging from the water (Williams 1936, pp. 303, 306, 309, 318). Fish
predation has been an important factor in the evolution of behavior in
damselfly naiads in continental systems (Johnson 1991, p. 8), and
damselflies in the wider-ranging Ishnura (as opposed to the Hawaiian
Megalagrion) may have developed avoidance behaviors (Polhemus 2014,
pers. comm.). On a survey of the stream (Okgok River, also known as
Babao) fed by the Talakhaya (Sonson) Water Cave, the presence of four
native fish species was noted: The eel Anguilla marmorata, the mountain
gobies Stiphodon elegans and Sicyopus leprurus, and the flagtail, or
mountain bass, Kuhlia rupestris (Camacho et al. 1997, p. 8). Densities
of these native fish were low, especially in areas above the waterfall.
Gobies can maneuver in areas of rapidly flowing water by using ventral
fins that are modified to form a sucking disk (Ego 1956, in litt.). The
flagtails were abundant only in the lower reach of the stream.
Freshwater gobies in Hawaii are primarily browsers and bottom feeders,
often eating algae off rocks and boulders, with midges and worms being
their primary food items (Ego 1956, in litt.; Kido et al. 1993, p. 47).
It can only be speculated that the Rota blue damselfly may have adapted
its behavior to avoid the benthic feeding habits of native fish
species. The release of aquarium fish into streams and rivers of Guam
is well documented, but currently, no nonnative fish have been found in
the Rota stream (Tibbatts 2014, in litt.).
The Rota blue damselfly appears to be extremely limited in range
and researchers remain perplexed by its absence from other Mariana
Islands (Polhemus et al. 2000, p. 8). Particularly striking is the fact
that it has never been collected on Guam, despite the islands' larger
size and presence of over 100 rivers and streams. The Rota blue
damselfly's population site (Talakhaya watershed area) is afforded some
protection from human impact by its remote and relatively inaccessible
location; however, a reduction or removal of stream flow due to
increased interception for municipal usage, and from lower water
quantities resulting from the effects of future climate change, could
eliminate one of the only two known populations of the species (see
``Stream Ecosystem,'' in the proposed rule (79 FR 59364; October 1,
2014), and Water Extraction under Factor E. Other Natural or Manmade
Factors Affecting Their Continued Existence, below, for further
discussion). Introduction of nonnative fish into the stream could also
impact or eliminate the Rota blue damselfly
[[Page 59445]]
naiads, leading to its extirpation. In addition, low numbers of
individuals results in loss of vigor and genetic representation, and
contributes to the vulnerability of the single known population of the
Rota blue damselfly.
Humped Tree Snail
The humped tree snail (Partula gibba; akaleha, denden), in the
Partulidae family, is endemic to the forest ecosystem on the Mariana
Islands of Guam, Rota, Saipan, Tinian, Aguiguan, Anatahan, Sarigan,
Alamagan, and Pagan. The humped tree snail was first collected on Guam
in 1819 by Quoy and Gaimard during the Freycinet Uranie expedition of
1817-1819 and was once considered the most abundant tree snail on Guam
(Crampton 1925, pp. 8, 25, 60). Currently, the humped tree snail is
known from the islands of Guam, (Hopper and Smith 1992, p. 81; Smith et
al. 2009, pp. 10, 12, 16), Rota (Smith 1995, p. 1; Bauman 1996, pp. 15,
18), Saipan (Hadfield 2010, pp. 20-21), Tinian (NavFac, Pacific 2014,
pp. 5-5--5-7), Sarigan (Hadfield 2010, p. 21), Alamagan (Bourquin 2002,
p. 30), and Pagan (Hadfield 2010, pp. 8-14), in the forest ecosystem.
The humped tree snail may occur on Aguiguan, but was not relocated on a
survey by Smith in 2006 (Smith 2013, p. 14). This species is no longer
extant on Anatahan due to volcanic activity in 2003 and 2005 (Kessler
2011, pp. 321, 323).
The shell of the humped tree snail can be left- or right-coiling,
conic-ovate, translucent, with evenly spaced spiral sculpturing (Cowie
2014, in litt.). The color ranges from white to brown, and a pointed
apex is colored rose-red, with a milky white suture. Adult snails are
from 0.6 to 0.7 in (14 to 18 mm) long, and 0.4 to 0.6 in (10 to 14 mm)
wide, with 4.5 whorls, the last of which is the largest (Pilsbry 1909-
1910, in Crampton 1925, p. 60; Smith et al. 2009, p. 2). In general,
partulid snails may live up to 5 years. They reproduce in less than 1
year, at which time they can produce up to 18 young each year.
Partulids are ovoviviparous (give birth to live young), more mobile
during higher ambient humidity and precipitation and less mobile during
dry periods, live on bushes or trees, and feed primarily on dead or
decaying plant material (Cowie 1992, p. 167; Hopper 2014, in litt.).
The humped tree snail occurs in cool, shaded forest habitat as
first observed by Crampton (Crampton 1925, pp. 31, 61), with high
humidity and reduced air movement that prevents excessive water loss.
Crampton (1925, pp. 31, 61) described the habitat requirements of the
partulid tree snails as having ``sufficiently high and dense growth to
provide shade, to conserve moisture, and to effect the production of a
rich humus. Hence the limits to the areas occupied by tree snails are
set by the more ultimate ecological conditions which determine the
distribution of suitable vegetation.'' Crampton further notes that the
Mariana Islands partulid tree snails live on subcanopy vegetation and
are not found in high canopy. Although tree snails in the Mariana
Islands likely evolved to live upon native vegetation, there is no
clear indication of obligate relationships with any particular type of
tree or plant (Fiedler 2014, in litt.). Further, Mariana partulid snail
species are observed to use nonnative ``home plants'' to which they
have apparently adapted (Fiedler 2014, in litt.). Although it has been
suggested that native crabs may prey on Mariana partulid snails
(Fiedler 2014, in litt.), they are not regarded as a major threat to
these tree snails compared to alien carnivorous flatworms (i.e., the
manokwari flatworm) and snails (i.e., the rosy wolf snail Euglandina
rosea and Gonaxis spp.) (Cowie 1992, p. 175). Nonnative mites and ants
have also raised some concerns about their impacts on Mariana partulid
snails (Fiedler 2014, in litt.); however, these are only potential
threats at this time.
Following is a brief historical overview of the humped tree snail
in the Mariana archipelago. Crampton (1925, pp. 8, 25, 60) first
observed the humped tree snail on Guam, in at least 39 sites, totaling
more than 3,000 individuals. In 1989, Hopper and Smith (1992, p. 81)
resurveyed 34 of Crampton's 39 sites and did not locate any live
individuals; however, they discovered individuals at a new site not
noted by Crampton. In 2009, the number of individuals of the humped
tree snail on Guam was thought to have declined from hundreds to fewer
than 50 individuals (Smith et al. 2009, p. 11); however, in 2014, a
previously undocumented population consisting of approximately 100
individuals was discovered (Fiedler 2014, in litt.; Myounghee Noh and
Associates 2014, pp. 1-28, and Appendices A and B), which brings the
total number of confirmed individuals on Guam to fewer than 150.
Bauman (1996, pp. 15, 18) surveyed Rota and reported finding live
humped tree snails at 5 out of 25 former sites. The largest of these
populations may have totaled as many as 1,000 snails. However, this
population was located along the main road of Rota and was subsequently
cleared for development (Miller 2007, pers. comm.), thus we conclude
this population is no longer extant since its suitable habitat at this
site was removed. Four other populations on Rota in 2007 were small and
totaled fewer than 600 individuals, collectively. Crampton was unable
to visit Tinian, although he states that tree snails were known from
that island (Crampton 1925, p. 6). Smith reported finding only very old
shells on two surveys (2006 and 2008) of Tinian (Smith 2013, p. 6). The
humped tree snail was thought to be extirpated from Tinian, until a
recent survey located a single colony in a very isolated spot on the
island (NavFac 2014, pp. 5-5--5-7).
The humped tree snail was discovered on Aguiguan in 1952, in six
colonies (biologists often refer to snail populations as ``colonies'')
(Kondo 1970, pp. 75, 81). In 1992, two separate surveys reported snails
observed at four locations on Aguiguan (Craig and Chandran 1992, p. 8;
Smith 1995, pp. 13-14), but by 2008, no live snails were found on this
island (Smith 2013, p. 14). On Saipan, Crampton collected almost 7,000
humped tree snails in 1925 (Crampton 1925, p. 62). By 1991, Smith and
Hopper (1994, p. 11) could not find any live snails at 12 sites visited
on the island; however, 2 small populations were later discovered, one
in 2002, in the central forest area, and another in a mangrove wetland
in 2010 (Bourquin 2002, in litt.; Hadfield 2010, pp. 20-21).
In 1994, Kurozumi reported approximately 20 individuals from
Anatahan; however, these were possibly extirpated due to violently
destructive volcanic eruptions between 2003 and 2005 (Kessler 2011, p.
321). Kurozumi also reported humped tree snails from Sarigan in 1994,
and the population appears to be increasing as a result of the removal
of ungulates. A survey of Sarigan in 2006 found the healthiest
population in native forest at an elevation of approximately 1,300 ft
(400 m) (Smith 2006 in Martin et al. 2008, p. 8-1). The species was
first reported on Alamagan by Kondo in 1949, with over 50 individuals
collected from wet forest (Easley 1970, p. 87). The populations have
declined on Alamagan by more than 70 percent for individuals and
approximately 27 percent for populations since that time (Kurozumi
1994, pp. 115-116). The humped tree snail was first reported from Pagan
by Kondo in 1949 (Easley 1970, p. 87). Populations persist on Pagan,
although declines similar to those on Alamagan have been observed
(Kurozumi 1994, pp. 115-116).
In summary, populations of the humped tree snail are rapidly
decreasing from initial numbers observed, and with continued habitat
loss and predation by nonnative species, are at risk. The effects of
future climate change are likely to have negative
[[Page 59446]]
impacts on the habitat of the humped tree snail, and further exacerbate
other threats to the species, such as threats from typhoons to small,
isolated populations. The populations on Sarigan may be relatively more
stable due to the removal of ungulates (see ``Conservation Efforts to
Reduce Habitat Destruction, Modification, or Curtailment of Its
Range,'' below), but predation by rats remains a threat on that island
(Kessler 2011, p. 320), as does the potential introduction of other
harmful nonnative species (Hopper 2014, in litt.). Collecting of snail
shells for trade may also contribute to the decline of the humped tree
snail (USFWS 2012, in litt.).
Preliminary new data, soon to be published but still under review,
suggest that the individuals identified as humped tree snails on Rota
may be a different species (Hadfield 2010, pp. 20-21; Sischo and
Hadfield 2015, under review). The species description for this newly
identified partulid on Rota, tentatively named Partula lutaensis, will
be published in a separate paper currently being drafted (Sischo 2015,
in litt.). However, we must make our determination based on the best
scientific data available, and at this point in time the humped tree
snail is recognized as a single species. Our determination is that the
humped tree snail, as currently described, warrants listing as an
endangered species. If taxonomic changes are made in the future, we may
reevaluate the status of any newly recognized species or subspecies at
that point in time.
Langford's Tree Snail
Langford's tree snail (Partula langfordi; akaleha, denden), in the
Partulidae family, is endemic to the forest ecosystem of the island of
Aguiguan. Langford's tree snail was first collected and described by
Kondo while working on biological control agents in the early 1950s
(Kondo 1970, 18 pp.). Kondo's taxonomic work is the most recent and
accepted taxonomy for this species. This tree snail has not been
observed in the wild since 1992, when one live individual was observed
on the northwest terrace of the island (Berger et al. 2005, p. 154).
Surveys conducted in 2006 and 2008 revealed only old shells of dead P.
langfordi (Smith 2013, p. 14).
Langford's tree snail has a dextral (to the right or clockwise from
the opening of the shell at the lower right, as opposed to sinistral,
to the left, or counterclockwise) shell, described by Kondo (1970, pp.
75-77) as being ovate-conic and moderately thin. The holotype of this
species has a length of 0.6 in (14 mm), a diameter of 0.4 in (9 mm),
and an aperture length of 0.3 in (8 mm). It has a spire of five whorls
that are slightly convex, with an obtuse apex. Its aperture is oblong-
ovate with the white mouth projections thickened and expanded. It is
buff colored superimposed by maroon.
Although much less studied than related partulid snails from the
Mariana Islands, the biology of Langford's tree snail is believed to be
the same. See ``Humped tree snail (Partula gibba),'' above, for
details.
Historically, Langford's tree snail is known only from the island
of Aguiguan. In the 1970 survey of Aguiguan, it was noted that
Langford's tree snail was collected from an area where it occurred
sympatrically with the humped tree snail (Easely 1970, p. 89). The
mixed populations were not uniformly distributed, but occurred in small
colonies with large unoccupied areas between the colonies. In five of
the sites, the Langford's tree snail outnumbered the humped tree snail,
and it appeared that humped tree snails were more numerous and dominant
in the western portion of the site while Langford's tree snails were
dominant in the eastern portion of the site (Kondo 1970, p. 81). Three
other colonies of Langford's tree snail were collected, two on the
north coast and one on the west end of Aguiguan (Kondo 1970, p. 81). A
total of 464 adults were collected from 7 sites (Kondo 1970, p. 81). In
1985, five adult Langford's tree snails were collected from the west
end of the island (Smith 1995). The last survey in which the species
was detected in the wild was conducted in 1992, and one live snail was
observed on the northwest terrace of the island (Smith 1995). Surveys
of Aguiguan in 2006 and 2008 failed to locate any live Langford's tree
snails (Smith 2013, p. 14).
In 1993, the University of Nottingham in England had six young and
four adult Langford's tree snails in captivity. By 1994, two adult
snails remained. Unfortunately, at the end of 1994, the last two
Langford's tree snails died (Pearce-Kelly et al. 1995, pp. 647-660).
The 2005 Comprehensive Wildlife Conservation Strategy for CNMI
(Division of Fish and Wildlife) (Berger et al. 2005) states that ``all
partulid snails are selected as a species of special conservation
need'' (p. 153), and that ``[Crampton] found as many as 31 snails on
the underside of a single leaf of caladium'' (p. 155) (demonstrating
that it would be easy to miss a large number of snails if that one
particular leaf were missed during a survey). This strategy outlines
conservation actions for Langford's tree snail, including more numerous
and intensive surveys, removal of goats from Aguiguan island, control
of nonnative species, and reforestation with native plants (Berger et
al. 2005, pp. 158-159). Given that so few surveys have been conducted
on Aguiguan, and only previously surveyed sites were ever revisited, it
is possible Langford's tree snail may be found.
In summary, Langford's tree snail is at risk from threats
associated with small numbers of individuals and populations (e.g.,
population declines through loss of vigor and genetic representation),
habitat loss and degradation by nonnative animals (goats and rats) and
development, and predation by nonnative animals (rats and flatworms).
Due to the small number of individuals and populations, natural events
such as typhoons also pose a threat, as a single catastrophic event
could potentially result in the extinction of the species. Further, the
collection of snail shells for trade may also contribute to the decline
of the humped tree snail (USFWS 2012, in litt.). Although not all of
the negative impacts that will result from climate change can be
predicted, the cumulative data suggest that climate change will impact
Langford's tree snails, likely by means of alteration of habitat to
less favorable conditions.
Guam Tree Snail
The Guam tree snail (Partula radiolata; akaleha, denden), in the
Partulidae family, is endemic to the forest ecosystem of Guam; this
species is not found on any other island. The Guam tree snail was first
collected by Quoy and Gaimard during the French Astrolabe expedition of
1828 and was initially named Bulimus (Partula) radiolatus by Pfeiffer
in 1846, which he changed to Partula radiolata in 1849 (Crampton 1925,
p. 34). Crampton's 1925 taxonomic work is the most recent and accepted
taxonomy for this species.
The shell of the Guam tree snail is pale straw-colored with darker
streaks and brown lines, and has impressed spiral lines. Adult length
is 0.5 to 0.7 in (13 to 18.5 mm), width is 0.3 to 0.5 in (8 to 12 mm),
with five slightly convex whorls (Pilsbry 1909-1910 in Crampton 1925,
p. 35; Smith et al. 2008 in Kerr 2013, p. 10). Juvenile Guam tree
snails are sometimes mistakenly identified as Samoana fragilis (Fielder
2014, in litt.). The biology of the Guam tree snail is very similar to
that of the humped tree snail (see ``Humped tree snail (Partula
gibba),'' above, for further description). The Guam tree snail prefers
the same cool, shaded forest habitat as the humped tree snail and
Langford's tree snail, described above.
Historically, suitable habitat for the Guam tree snail was widely
available
[[Page 59447]]
prior to World War II, and included strand vegetation, forested river
borders, and lowland and highland forests; as Crampton (1925, pp. 36-
37) described, ``it occurs almost everywhere on the island where
suitable vegetation exists,'' although historical population numbers
are unknown. Crampton (1925, pp. 38-40) found the Guam tree snail at 37
of 39 sites surveyed on Guam and collected a total of 2,278
individuals. The actual population sizes were probably considerably
larger since the purpose of Crampton's collections was to evaluate
geographic differences in shell patterns and not to assess population
size. In 1989, Hopper and Smith (1992, p. 78) resurveyed 34 of
Crampton's 39 sites on Guam and an additional 13 new sites. They
observed that 9 of the original 34 sites resurveyed supported these
snails; however, the Crampton site identified as having the largest
remaining population of the Guam tree snail (estimated at greater than
500 snails) had been completely eliminated by the combined effects of
land clearing for a residential development and a subsequent series of
typhoons in 1990, 1991, and 1992 (Smith 1995, pp. 6-11).
Of the 13 new sites surveyed by Hopper and Smith in 1989, 7
supported populations of the Guam tree snail. One of these populations
was eliminated by wildfires that burned into ravine forest occupied by
the snails in 1991 and 1992 (Smith and Hopper 1994, pp. 10-11). Further
surveys by Smith (1995, pp. 1-25) revealed five new populations of the
Guam tree snail. According to Smith, by 1995, there were 20 sites that
still supported small populations of the Guam tree snail. Snails were
moved from 1 of these 20 sites to a new location due to the development
of a golf course (Smith 1995, pp. 6-11). In 2003 an additional small
colony (fewer than 100 snails) was found on the U.S. Naval Base (Smith
2006, pers. comm.). A smaller colony (20 to 25 snails) was found in
2004 along the Lonfit River (Smith 2006, pers. comm.). Additionally,
surveys on the Guam Naval Magazine located another new population, with
shells of tree snails in abundance on the ground at all locations
(Miller 2006, pers. comm.; JGPO-NavFac 2014 apps, pp. 27, 59).
Further surveys of lands leased by the Navy in 2009 indicated a
decline in densities of tree snails by about half, which was attributed
to a loss of native understory (Smith et al. 2009, pp. 13-14). In 2011,
a survey of Andersen AFB revealed a single colony of Guam tree snail
(Joint Regional Marianas Integrated Natural Resources Management Plan
Appendices 2012, p. 15). In 2013, a survey team on Guam observed small
colonies of the Guam tree snail (ranging from 10 to 150 individuals per
colony) at approximately 20 sites around the island (Lindstrom and
Benedict 2014, p. 27). A 2014 study conducted solely at the Haputo
Ecological Reserve Area (HERA) and adjacent forested areas counted
almost 1,500 live Guam tree snails (Myounghee Noh and Associates 2014,
pp. 1-28, and Appendices A and B); however, there are nonnative
ungulates (pigs and deer) and the manokwari flatworm in the area
(Lindstrom and Benedict 2014, pp. 32-33; Myounghee Noh and Associates
2014, p. B-8), all of which pose threats to the Guam tree snail. Some
snail experts who frequently conduct fieldwork in the Mariana Islands
have reported there are at least 26 populations of the Guam tree snail;
however, they also note that habitat destruction and the manokwari
flatworm still pose significant threats to this species, which is
particularly vulnerable as a single-island endemic (Fiedler 2014, in
litt.).
Lindstrom and Benedict (2014, p. 27) conducted a genetic analysis
using snail slime collected at 20 sites around Guam. The results from
this genetic analysis showed the Guam tree snail has a very low degree
of genetic diversity between all the surveyed populations, which makes
this species vulnerable to extinction pressures associated with low
numbers of individuals and populations (e.g., disease). Additionally,
despite being the most widespread partulid on Guam, Lindstrom and
Benedict's data (2014, pp. 27, 31, 32) show that Guam tree snails are
still disappearing compared to historical abundance (Lindstrom and
Benedict 2014, p. 32).
Overall, populations of the Guam tree snail continue to decline,
from first observations of at least 37 populations as observed by
Crampton, down to 26 colonies or fewer today. Continued loss of habitat
due to development and removal of native plants by ungulates contribute
to this loss, trade of shells by collectors may be a threat, and
predation by the invasive manokwari flatworm is likely a significant
source of mortality (see Summary of Biological Status and Threats
Affecting the 23 Mariana Islands Species, below). We anticipate the
effects of climate change will further exacerbate many of these threats
in the future.
Fragile Tree Snail
The fragile tree snail (Samoana fragilis; akaleha dogas, denden),
in the Partulidae family, is known from the forest ecosystems of Guam
and Rota. This species was first described as Partula fragilis by
F[eacute]russac in 1821 (Crampton 1925, p. 30). It is the only species
representing the genus of Samoana in the Mariana Islands. The fragile
tree snail was first collected on Guam in 1819 by Quoy and Gaimard
during the Freycinet Uranie expedition of 1817 to 1819 (Crampton 1925,
p. 30). Crampton's 1925 taxonomic work for this species is the most
recent and accepted taxonomy for this species.
The conical shell of the fragile tree snail is 0.5 to 0.6 in (12 to
16 mm) long, 0.4 to 0.5 in (10 to 12 mm) wide, and is formed by four
whorls that spiral to the right. The common name is derived from the
thin, semi-transparent nature of the shell. The shell has delicate
spiral striations intersected by transverse growth striations. The
background color is buff, tinted by narrow darker marks and whitish
banding that are derived from the internal organs of the animal that
are visible through the shell (Mollendorff 1894 in Crampton 1925, p.
31). Sometimes the Guam tree snail and fragile tree snail are difficult
to distinguish from one another and DNA comparison is necessary to
determine the identity (Fiedler 2014, in litt.). The biology and
habitat for this partulid tree snail are the same as those described
for the three partulid species described above (see the ``Humped tree
snail (Partula gibba),'' above).
Historically, the fragile tree snail was known from 13 populations
on Guam and 1 population on Rota (Crampton 1925, p. 30; Kondo 1970, pp.
86-87). Easely (1970, p. 86) documented the 1959 discovery of the
fragile tree snail on Rota by R.P. Owen. The same area had been
surveyed just 7 years earlier by Benavente and Kondo, in 1952, but the
fragile tree snail was not observed (Easley 1970, p. 87). In 1989,
Hopper and Smith (1992, p. 78) resurveyed Crampton's original sites
plus 13 more, all on Guam. At that time, they found fragile tree snails
at only six sites. The most recent surveys on Guam for the fragile tree
snail were conducted in 2008, 2011, 2013, and 2014. Currently, two
colonies are known on Guam (Smith et al., 2009, pp. 7, 13; Myounghee
Noh and Associates 2014, pp. 1-28, and Appendices A and B; Lindstrom
and Benedict 2014, pp. 1-44, and Appendices A-E). Lindstrom and
Benedict (2014, p. 30) found no genetic heterogeneity between the two
populations on Guam, indicative of a small population that has
undergone a population bottleneck, which makes this species less
resilient evolutionarily and more vulnerable to extinction pressures.
The original site where this species was found on Rota was converted to
agricultural fields, and no
[[Page 59448]]
living snails were found there in 1995; however, in 1996, a new colony
was found on Rota in a different location (Bauman 1996, pp. 18, 21).
We lack quantitative estimates of population sizes for the fragile
tree snail (Bauman 1996, p. 21), but Crampton (1925, p. 30) originally
described this species as rare and low in numbers. Available data
indicate the number of known colonies has declined between 1925 and the
present, from approximately 14 colonies to only 3 colonies.
In summary, populations of the fragile tree snail are decreasing
from initial numbers observed on Guam and Rota, and are at risk, due to
continued habitat loss and destruction from agriculture, urban
development, nonnative animals and plants, and typhoons. We anticipate
the effects of climate change will further exacerbate many of these
threats in the future. Trade of shells by collectors, combined with
direct predation by rats and flatworms, also contribute to the decline
of the fragile tree snail. Low numbers of individuals likely contribute
to population declines through loss of vigor and genetic
representation.
Summary of Biological Status and Threats Affecting the 23 Mariana
Islands Species
Section 4 of the Act (16 U.S.C. 1533) and its implementing
regulations (50 CFR part 424) set forth the procedures for adding
species to the Federal Lists of Endangered and Threatened Wildlife and
Plants. A species may be determined to be an endangered or threatened
species due to one or more of the five factors described in section
4(a)(1) of the Act: (A) The present or threatened destruction,
modification, or curtailment of its habitat or range; (B)
overutilization for commercial, recreational, scientific, or
educational purposes; (C) disease or predation; (D) the inadequacy of
existing regulatory mechanisms; and (E) other natural or manmade
factors affecting its continued existence. Listing actions may be
warranted based on any of the above threat factors, singly or in
combination. Each of these factors is discussed below.
In considering what factors might constitute threats to a species,
we must look beyond the exposure of the species to a particular factor
to evaluate whether the species may respond to that factor in a way
that causes actual impacts to the species. If there is exposure to a
factor and the species responds negatively, the factor may be a threat,
and, during the status review, we attempt to determine how significant
a threat it is. The threat is significant if it drives, or contributes
to, the risk of extinction of the species such that the species
warrants listing as an endangered or threatened species as these terms
are defined in the Act. However, the identification of factors that
could impact a species negatively may not be sufficient to warrant
listing the species under the Act. The information must include
evidence sufficient to show that these factors are operative threats
that act on the species to the point that the species meets the
definition of an endangered or threatened species under the Act.
If we determine that the level of threat posed to a species by one
or more of the five listing factors is such that the species meets the
definition of either endangered or threatened under section 3 of the
Act, that species may then be proposed for listing as an endangered or
threatened species. The Act defines an endangered species as ``in
danger of extinction throughout all or a significant portion of its
range,'' and a threatened species as ``likely to become an endangered
species within the foreseeable future throughout all or a significant
portion of its range.'' The threats to each of the individual 23
species listed as endangered or threatened species in this final rule
are summarized in Table 3, and discussed in detail below. Since there
are 15 islands in the Mariana Islands, Table 4 (below) is provided as a
supplement to Table 3, to allow the reader to better understand the
presence of nonnative species addressed in this final rule that
negatively impact the 23 species on an island-by-island basis.
[[Page 59449]]
Table 3--Summary of Primary Threats Identified for Each of the 23 Mariana Islands Species
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Factor A Factor B Factor C Factor D Factor E
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Development, Predation and Predation and Inadequate
Species Ecosystem military Non- native Non- Climate Predation and herbivory by herbivory by existing Species-
training, animals native Fire Typhoons change Overutilization herbivory by nonnative nonnative regulatory specific
urbanization plants ungulates vertebrates invertebrates mechanisms
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Plants
Bulbophyllum guamense.......... FR............. X R, BTS......... X X X X ............... ............... ............... S.............. X ...............
Cycas micronesica.............. FR............. X R, P, B, D, BTS X X X X ............... P, D........... ............... CAS............ X ORD
Dendrobium guamense............ FR............. X R, BTS......... X X X X ............... ............... ............... S.............. X ...............
Eugenia bryanii................ FR............. X R, D, BTS...... X .......... X X ............... D.............. ............... ............... X ...............
Hedyotis megalantha............ SV............. X R, P, BTS...... X X X X ............... ............... ............... ............... X REC
Heritiera longipetiolata....... FR............. X R, P, B, D, BTS X .......... X X ............... P, D........... ............... ............... X ORD
Maesa walkeri.................. FR............. X R, P, B, D, BTS X X X X ............... ............... ............... ............... X ...............
Nervilia jacksoniae............ FR............. X P, B, D, R, BTS X X X X ............... ............... ............... S.............. X ...............
Phyllanthus saffordii.......... SV............. X R, P, BTS...... X X X X ............... ............... ............... ............... X REC
Psychotria malaspinae.......... FR............. X R, P, B, D, BTS X .......... X X ............... P, D........... ............... ............... X LN, ORD
Solanum guamense............... FR............. X R, P, D, BTS... X .......... X X ............... P, D........... ............... ............... X LN
Tabernaemontana rotensis....... FR............. X R, P, B, D, BTS X X X X ............... ............... ............... ............... X ORD
Tinospora homosepala........... FR............. ............... R, BTS......... X .......... X X ............... ............... ............... ............... X LN
Tuberolabium guamense.......... FR............. X R, BTS......... X X X X ............... ............... ............... S.............. X ...............
Animals
Pacific sheath-tailed bat FR, CA......... X R, G........... .......... .......... X X ............... ............... R, BTS, ML..... ............... X LN
(Emballonura semicaudata
rotensis).
Slevin's skink................. FR............. X R, G, P,....... .......... .......... X X ............... ............... R, BTS, ML..... ............... X ORD
(Emoia slevini)................
Mariana eight spot butterfly FR............. X R, P, B, D, BTS X .......... X X ............... ............... ............... A, W........... X LN, ORD
(Hypolimnas octocula
marianensis).
Mariana wandering butterfly FR............. ............... R.............. .......... .......... X X ............... ............... ............... A, W........... X LN
(Vagrans egistina).
Rota blue damselfly (Ischnura ST............. X ............... X .......... X X ............... ............... ............... ............... X LN, WE
luta).
Humped tree snail (Partula FR............. X R, G, P, B, C, X X X X X ............... R.............. F.............. X ORD
gibba). D, BTS.
Langford's tree snail (Partula FR............. X R, G........... X .......... X X X ............... R.............. F.............. X LN
langfordi).
Guam tree snail (Partula FR............. X R, P, B, D, BTS X X X X X ............... R.............. F.............. X LN
radiolata).
Fragile tree snail (Samoana FR............. X R, P, B, D, BTS X .......... X X X ............... R.............. F.............. X LN
fragilis).
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Factor A = Habitat modification;
Factor B = Overutilization;
Factor C = Disease or predation;
Factor D = Inadequacy of regulatory mechanisms;
Factor E = Other Species-specific threats;
FR = Forest;
SV = Savanna;
ST = Stream;
CA = Cave;
R = Rats;
P = Pigs;
B = Water buffalo;
D = Deer;
C = Cattle;
G = Goats;
S = Slugs;
CAS = Scale;
ML = Monitor lizard;
A = Ants;
W = Parasitic wasps;
F = Manokwari flatworm;
BTS = Brown treesnake;
REC = Recreational vehicles;
ORD = Ordnance;
LN = Limited numbers;
WE = Water extraction.
[[Page 59450]]
Table 4--Nonnative Animal Species That Negatively Impact the 23 Mariana Islands Species or Their Habitat, by Island
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Species subject to threats posed by
Brown nonnative animal species on these islands
Island Pigs Goats Cattle Water Deer Rats Monitor Tree- Insects and worms (see Table 3, above)
Buffalo Lizard snake ---------------------------------------------
Plants Animals
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Guam............................... X ......... ......... X X X * X X A, W, F, S, CAS...... Bulbophyllum Slevin's skink (on
guamense, Cycas Cocos Island),
micronesica, Mariana eight-spot
Dendrobium guamense, butterfly, Mariana
Eugenia bryanii, wandering butterfly,
Hedyotis megalantha, Guam tree snail,
Heritiera Humped tree snail,
longipetiolata, Fragile tree snail.
Maesa walkeri,
Nervilia jacksoniae,
Phyllanthus
saffordii,
Psychotria
malaspinae, Solanum
guamense,
Tabernaemontana
rotensis, Tinospora
homosepala,
Tuberolabium
guamense.
Rota............................... ......... ......... ......... ......... X X * X ** X A, W, F, S, CAS...... Bulbophyllum Mariana wandering
guamense, Cycas butterfly, Rota blue
micronesica, damselfly, Humped
Dendrobium guamense, tree snail, Fragile
Heritiera tree snail.
longipetiolata,
Maesa walkeri,
Nervilia jacksoniae,
Tabernaemontana
rotensis,
Tuberolabium
guamense.
Aguiguan........................... ......... X ......... ......... ......... X * X ......... F.................... Dendrobium guamense.. Pacific sheath-tailed
bat, Humped tree
snail, Langford's
tree snail.
Tinian............................. ......... ......... ......... ......... ......... X * X ......... F.................... Dendrobium guamense Humped tree snail.
Heritiera
longipetiolata.
Saipan............................. ......... ......... ......... ......... ......... X * X ** X A, W, F.............. Heritiera Mariana eight-spot
longipetiolata. butterfly, Humped
tree snail.
Farallon de Medinilla.............. ......... ......... ......... ......... ......... X ......... ......... ..................... ..................... .....................
Anatahan........................... ......... ......... ......... ......... ......... X * X ......... ..................... ..................... .....................
Sarigan............................ ......... ......... ......... ......... ......... X * X ......... [dagger] F........... ..................... Slevin's skink,
Humped tree snail.
Guguan............................. ......... ......... ......... ......... ......... X ......... ......... [dagger] F........... ..................... Slevin's skink.
Alamagan........................... X X X ......... ......... X * X ......... [dagger] F........... ..................... Slevin's skink,
Humped tree snail.
Pagan.............................. X X X ......... ......... X * X ......... [dagger] F........... Cycas micronesica . Slevin's skink,
Humped tree snail.
Agrihan............................ X X ......... ......... ......... X * X ......... ..................... ..................... .....................
Asuncion........................... ......... ......... ......... ......... ......... X ......... ......... ..................... ..................... Slevin's skink.
Maug............................... ......... ......... ......... ......... ......... X ......... ......... ..................... ..................... .....................
Uracas............................. ......... ......... ......... ......... ......... X ......... ......... ..................... ..................... .....................
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
A = Ants.
W = Parasitic wasp.
F = Manokwari flatworm.
S = Slugs.
CAS = Cycad aulacaspis Scale.
* Animals only.
** Confirmed sightings of brown treesnakes have occurred on Saipan and Rota; however, no established populations have been documented.
[dagger] Not yet documented, but high potential to spread to these islands.
Sec. Tentative, to be confirmed.
Methods
The available scientific research on each of the species listed as
endangered or threatened species in this final rule is limited because
of their rarity and the challenging logistics associated with
conducting fieldwork in the Mariana Islands (i.e., areas are typically
remote, difficult to access and work in, and expensive to survey in a
comprehensive manner). However, there is information available on many
of the threats that act on Mariana Island ecosystems, and, for some
ecosystems, these threats are well studied and understood. Each of the
native species that occur in the Mariana Islands ecosystems suffers
from exposure to these threats because each species that depends upon a
shared ecosystem requires many of the same physical and biological
features and the
[[Page 59451]]
successful functioning of their specific ecosystem to survive, and in
some cases, this information is the best and only information available
to assess threats to the species. In addition, in some cases we have
identified species-specific threats--threats that affect only a
particular species or subset of species within a shared ecosystem--such
as predation of tree snails by nonnative invertebrates. The species
discussed in this final rule, which are dependent on the native
ecosystems that are affected by these threats, have in turn shown
declines in either number of individuals, number of occurrences, or
changes in species abundance and species composition. These declines
can reasonably be attributed directly or indirectly to the threats
discussed below. By indirectly, we mean that where there are threats to
the ecosystem that negatively affect the ecosystem, the species in that
ecosystem that depend upon it for survival are negatively affected as
well.
The following constitutes a list of ecosystem-scale threats that
affect the 23 species addressed in this final rule, in the four
described ecosystems on the Mariana Islands:
(1) Foraging and trampling of native plants by feral pigs, goats
(Capra hircus), cattle (Bos taurus), water buffalo (Bubalus bubalis),
and Philippine deer (Cervus mariannus), which can result in severe
erosion of watersheds (Cuddihy and Stone 1990, p. 63; Berger et al.
2005, pp. 42, 44, 138, 156-157; CNMI-SWARS 2010, pp. 9-10; Kessler
2011, pp. 320-324). Foraging and trampling events destabilize soils
that support native plant communities, bury or damage native plants,
and have adverse effects on water quality due to runoff over exposed
soils (Cuddihy and Stone 1990, p. 63; Berger et al. 2005, pp. 42, 44,
138, 156-157; CNMI-SWARS 2010, pp. 9-10; Kessler 2011, p. 323).
(2) Ungulate destruction of seeds and seedlings of native plant
species through foraging and trampling facilitates the conversion of
disturbed areas from native to nonnative vegetative communities
(Cuddihy and Stone 1990, p. 65).
(3) Disturbance of soils by feral pigs from rooting can create
fertile seedbeds for alien plants, some of them spread by ingestion and
excretion by pigs (Cuddihy and Stone 1990, p. 65; Kessler 2011, pp.
320, 323).
(4) Increased nutrient availability as a result of pigs rooting in
nitrogen-poor soils, which facilitates establishment of alien weeds.
Introduced vertebrates are known to enhance the germination of alien
plants through seed scarification in digestive tracts or through
rooting and fertilization with feces of potential seedbeds (Stone 1985,
p. 253). In addition, alien weeds are more adapted to nutrient-rich
soils than native plants (Cuddihy and Stone 1990, p. 65), and rooting
activity creates open areas in forests, allowing alien species to
completely replace native stands.
(5) Rodent damage to plant propagules, seedlings, or native trees,
which changes forest composition and structure (Cuddihy and Stone 1990,
p. 67).
(6) Feeding or defoliation of native plants by nonnative insects,
which can reduce geographic ranges of some species, because the damage
caused by these insects weakens the plants, making them more
susceptible to disease or other predators and herbivores (Cuddihy and
Stone 1990, p. 71).
(7) Nonnative insect predation on native insects, which affects
native plant species by preventing pollination and seed set and
dispersal, and can directly kill native insects (Cuddihy and Stone
1990, p. 71).
(8) Nonnative animal (rat, snake, and monitor lizard) predation on
native birds, tree snails, bats, and skinks causes island extirpations
or extinctions, in addition to altering seed dispersal of native plants
(Cuddihy and Stone 1990, pp. 72-73).
(9) Future effects from climate change. Although we do not have
specific information on the impacts of the effects of climate change to
the 23 species, projected increases in ambient temperature and
precipitation, as well as increased severity of typhoons, will likely
exacerbate other threats to these species as well as provide additional
stresses on their habitats. The probability of species extinction as a
result of climate change impacts increases when its range is
restricted, habitat decreases, and numbers of populations decline (IPCC
2007, p. 48), as is the case for the 23 species under consideration
here.
Each of the above threats is discussed in more detail below, and
summarized above in Table 3. The most-often cited effects of nonnative
plants on native plant species are competition and displacement.
Competition may be for water, light, or nutrients, or it may involve
allelopathy (chemical inhibition of growth of other plants). Alien
plants may displace native species of plants by preventing their
reproduction, usually by shading and taking up available sites for
seedling establishment. Alien plant invasions may also alter entire
ecosystems by forming monotypic stands, changing fire characteristics
of native communities, altering soil-water regimes, changing nutrient
cycling, or encouraging other nonnative organisms (Vitousek et al.
1987, pp. 224-227; Smith 1989, p. 62).
Factor A. The Present or Threatened Destruction, Modification, or
Curtailment of Its Habitat or Range
Habitat Destruction and Modification by Development, Military Training,
and Urbanization
The consequences of past land use practices, such as agricultural
or urban development, have resulted in little or no native vegetation
remaining throughout the inhabited islands of the Mariana archipelago,
largely impacting the forest, savanna, stream, and cave ecosystems
(Steadman 1990, pp. 207-215; Steadman 1995, pp. 1,123-1,131; Fritts and
Rodda 1998, pp. 119-120; Critical Ecosystem Partnership Fund 2007, pp.
i-viii, 1-127). Areas once used for agriculture by the Chamorro are now
being converted into residential areas, left fallow, or are being
burned by hunters to attract deer (GDAWR 2006, p. 30; Boland 2014, in
litt.). Guam's projected population increase by 2040 to 230,000 is an
increase of almost 70 percent from that in 2010 (World Population
Review 2014, in litt.). CNMI's current population of a little more than
51,000 is a decrease from that in 2010, due to collapse of the local
garment industry (Eugenio 2009, in litt.). In their 2015 Final SEIS
(http://guambuildupeis.us/) (see ``Historical and Ongoing Human
Impacts,'' above), the U.S. Department of Navy states that
approximately 5,000 Marines will be relocated from Okinawa to Guam,
accompanied by approximately 1,300 dependents, with a concurrent
introduction of support staff and development of infrastructure, and
increased use of resources such as water (Berger et al. 2005, p. 347;
JGPO-NavFac, Pacific 2015, p. ES-3).
The military buildup on Guam was originally valued in excess of $10
billion (2.5 times the size of the current Guam economy), and was
planned to take place over 4 years (Guam Economic Development Authority
2011, p. 58). The scope of the relocation of personnel has decreased
since this estimate in 2011, but the relocation will still greatly
affect infrastructure and resource needs (JGPO-NavFac, Pacific 2015, p.
ES 3; CJMT EIS-OEIS 2015, pp. ES-1-ES-77; http://www.cnmijointmilitarytrainingeis.com/). The current preferred
alternative sites on Guam for cantonment and live-fire training include
the Naval Computer and Telecommunications Station Finegayan and
Northwest Field on Andersen AFB,
[[Page 59452]]
where, in total, 16 of the 23 species or their habitat are known to
occur (11 of the 14 plants: Bulbophyllum guamense, Cycas micronesica,
Dendrobium guamense, Eugenia bryanii, Heritiera longipetiolata, Maesa
walkeri, Nervilia jacksoniae, Psychotria malaspinae, Solanum guamense,
Tabernaemontana rotensis, and Tuberolabium guamense; and 5 of the 9
animals: The Mariana eight-spot butterfly, the Mariana wandering
butterfly, the Guam tree snail, the humped tree snail, and the fragile
tree snail), and additionally includes the host plants Procris
pendunculata and Elatostema calcareum for the Mariana eight-spot
butterfly and the host plant Maytenus thompsonii for the Mariana
wandering butterfly. Further, the Navy is planning jungle training at
the Naval Munitions Site (NMS) on Guam, which will require the
establishment of foot trails within the southern portion of the NMS due
to repeat use during maneuvering training. At least 5 of the 23 species
(the plants Cycas micronesica, Maesa walkeri, Psychotria malaspinae,
and Tuberolabium guamense; and the Guam tree snail) are known to occur
on the Naval Magazine.
The inhabited island of Tinian and the uninhabited island of Pagan
are planned to be used for military training with live-fire weapons and
presence of military personnel (see ``Historical and Ongoing Human
Impacts,'' above). The northern two-thirds of Tinian are leased by the
U.S. Department of Defense, and the development of these lands and
effects from live-fire training will directly impact the tree Heritiera
longipetiolata and the humped tree snail, and their habitat in the
forest ecosystem. Pagan is occupied by Slevin's skink, the humped tree
snail, and tentatively Cycas micronesica; and is historical habitat of
Bulbophyllum guamense, all of which will be negatively impacted by
direct destruction by live-fire weapons or possible wildfires caused by
them and by trampling and destruction by military personnel.
Most private lands on the island of Rota are on flat or low sloping
ground. Low sloping grounds comprise approximately 66 percent of Rota's
land base, and at least 75 percent of these lands are, or will soon be,
committed to private use (CNMI Talakhaya-Sabana Conservation Action
Plan (TSCAP)-CNMI Division of Environmental Quality (CNMI DEQ) 2012, p.
7). CNMI government programs call for the transfer of portions of
public lands from public to private ownership through agriculture or
village homestead programs (TSCAP-CNMI DEQ 2012, p. 7). In November
2007, the people of Rota voted to legalize casino gambling to increase
tourism, and two development projects have been proposed. First, the
Treasure Island Casino, which will build upon the existing Rota Hotel
(CNMI Tourism Master Plan 2012, pp. 128-129; Zotomayor 2014, in litt.);
and second, a casino designed around the existing Rota Resort and
Country Club. Rota currently has seven operational hotels, and tourism
is one of the island's primary industries, although a lack of reliable
transportation currently limits the amount of visitors (CNMI Tourism
Master Plan 2012, pp. 128-129). The 2012 CNMI Tourism Master Plan
outlines ways to increase tourism and improve infrastructure on Saipan,
Tinian, and Rota. Further development on Rota will cause an increase of
water use, which will subsequently impact the Talakhaya Springs and the
streams fed by the springs, as the Talakhaya Springs are the primary
source of water used for human development on Rota. Specifically,
dewatering of the streams on Rota could lead to elimination of the only
known population of the Rota blue damselfly (see ``Water Extraction,''
below). Additionally, development around and within forested areas on
Rota will also directly impact the forest habitat and individuals of
Bulbophyllum guamense, Cycas micronesica, Dendrobium guamense,
Heritiera longipetiolata, Maesa walkeri, Nervilia jacksoniae,
Tabernaemontana rotensis, and Tuberolabium guamense; and the habitat
and host plants of the Mariana wandering butterfly, and the humped tree
snail and fragile tree snail.
Other urban development (primarily involving housing development)
will further impact the ecosystems that support native species. On
Guam, a housing development is proposed for the Sigua highlands, where
two of the plant species (Hedyotis megalantha and Phyllanthus
saffordii) addressed in this rule are known to occur (Kelman 2013, in
litt.). In addition, the island of Aguiguan is proposed to be developed
as an ecotourism resort (Eugenio 2013, in litt.). If developed, this
ecotourism resort will negatively impact the forest and cave ecosystems
that support three of the animals (the Pacific sheath-tailed bat, the
humped tree snail, and Langford's tree snail) listed as endangered
species in this final rule, by causing destruction of the forest
ecosystem (and associated food sources for the Pacific sheath-tailed
bat) for development of tourist facilities for transportation and
accommodation, by associated introduction of nonnative predators and
herbivores, and by causing direct disturbance by visitation of caves.
The total land area for all of the northern islands (within these
species' current and historical range) is only 62 mi\2\ (160 km\2\),
and 44 mi\2\ (114 km\2\) of this land area is on islands with volcanic
activity, which could impact the species and their habitat. The larger
land area on the southern islands (332 mi\2\ (857 km\2\)), within these
species' current and historical range, is undergoing increased human
use, as described above.
In summary, development, military training, urbanization (Guam DAWR
2006, p. 69), and the associated destruction or degradation of habitat
through loss of forest and savanna areas, disturbance of caves, and
dewatering of streams, are serious threats to 13 of the 14 plants
(Bulbophyllum guamense, Cycas micronesica, Dendrobium guamense, Eugenia
bryanii, Hedyotis megalantha, Heritiera longipetiolata, Maesa walkeri,
Nervilia jacksoniae, Phyllanthus saffordii, Psychotria malaspinae,
Solanum guamense, Tabernaemontana rotensis, and Tuberolabium guamense),
and to 8 of the 9 animals (the Pacific sheath-tailed bat, Slevin's
skink, the Mariana eight-spot butterfly, the Rota blue damselfly, the
Guam tree snail, the humped tree snail, Langford's tree snail, and the
fragile tree snail) that are dependent on these ecosystems. We do not
have sufficient information specific to 2 of the 23 species, Tinospora
homosepala and the Mariana wandering butterfly, that would lead us to
conclude that habitat loss as a result of development, military
training, or urbanization is a threat to these species. For a more
thorough discussion of previous occupations and current U.S. military
activities, see ``Historical and Ongoing Human Impact,'' above.
Habitat Destruction and Modification by Nonnative Animals
Animal species introduced by humans, either intentionally or
accidentally, are responsible for some of the greatest negative impacts
to the four Mariana Islands ecosystems described here (Stone 1970, pp.
14, 32; Intoh 1986 in Conry 1988, p. 26; Fritts and Rodda 1998, p.
130). Although there are numerous reports of myriad introduced animal
species that have negatively impacted the four described Mariana
Islands ecosystems, ranging from ungulates to insects (including such
diverse animals as the musk shrew (Suncus murinus), dogs (Canis lupis
familiaris), cats (Felis catus), and black drongoes (birds; Dicrurus
macroercus)),
[[Page 59453]]
we have focused our efforts here on the negative impacts of those
species that impose the greatest harmful effects on the four ecosystems
(see Tables 3 and 4, above). In addition, we address the compounding
effects on these ecosystems that arise when the pressure of two or more
individual negative impacts is greater than the sum of their parts
(i.e., synergistic effects). Below we discuss the negative impacts of
various nonnative animals, including feral pigs, goats, cattle, and
water buffalo, as well as Philippine deer, rats, and the brown
treesnake, which impose the greatest adverse impacts on one or more of
the 4 described Mariana Islands ecosystems (forest, savanna, stream,
and cave) that support the 23 species addressed in this final rule
(Stone 1970, pp. 14, 32; Intoh 1986 in Conry 1988, p. 26; Fritts and
Rodda 1998, pp. 130-133; Berger et al. 2005, pp. 42, 44, 138, 156-157;
CNMI-SWARS 2010, pp. 7, 24). Because most of the islands in the Mariana
archipelago are small (Guam being the largest), the negative impacts
associated with a destructive nonnative animal species affect the
entire island. The mild climate of the islands, combined with the lack
of competitors or predators, has led to the successful establishment of
large populations of these introduced animals, to the detriment of the
native Mariana Island species and ecosystems. These effects are
discussed in more detail, below.
Habitat Destruction and Modification by Introduced Ungulates
Like most oceanic islands, the Mariana Islands, and greater
Micronesia, did not support indigenous populations of terrestrial
mammalian herbivores prior to human colonization (Wiles et al. 1999, p.
194). Although agriculture and land use by the Chamorro clearly altered
the landscape and composition of native biota in the Mariana Islands,
starting more than 3,500 years ago (Perry and Morton 1999, p. 126;
Steadman 1995, pp. 1,126-1,127), impacts to the native species and
ecosystems of the Marianas accelerated following the arrival of
Magellan in the 1500s (Pregill 1998, p. 66; Perry and Morton 1999, pp.
126-127). The Spanish and subsequent explorers intentionally introduced
pigs, cattle, goats, water buffalo, and Philippine deer to serve as
food sources (Fosberg 1960, p. 54; Conry 1988, pp. 26-28). The
isolation of the Mariana Islands allowed plant species to evolve
without defenses to browsing and grazing animals, such as secondary
metabolites and spines, making them highly susceptible to herbivory
(Bowen and Van Vuren 1997, p. 1,249; Wiles et al. 1999, p. 194).
Introduced mammals have profoundly influenced many insular ecosystems
around the globe through alteration of the physical environment,
culminating in the decline and loss of native biota (Stone 1970, pp.
14, 32; Scowcroft and Giffin 1983 in Wiles et al. 1999, p. 194; Stone
1985, pp. 251, 253-263; Campbell and Donlan 2004, pp. 1,363, 1,365),
including the Mariana Islands ecosystems (Conry 1988, pp. 27-28;
Mueller-Dombois and Fosberg 1998, pp. 250-252, 264; Berger et al. 2005,
pp. 42, 44, 138, 156-157; CNMI-SWARS 2010, pp. 7, 24).
The presence of alien mammals is considered one of the primary
factors underlying the alteration and degradation of native plant
communities and habitats on the Mariana Islands. The destruction or
degradation of habitat due to nonnative ungulates, including pigs,
goats, cattle, water buffalo, and deer, is currently a threat to 17 of
the 23 species addressed in this final rule, in 2 of the 4 ecosystems
(forest and savanna) on 7 of the 15 Mariana Islands (Guam, Rota,
Aguiguan, Tinian, Alamagan, Pagan, and Agrihan). Habitat degradation or
destruction by ungulates is a threat to 10 of the 14 plant species
(Cycas micronesica, Eugenia bryanii, Hedyotis megalantha, Heritiera
longipetiolata, Maesa walkeri, Nervilia jacksoniae, Phyllanthus
saffordii, Psychotria malaspinae, Solanum guamense, and Tabernaemontana
rotensis), and 7 of the 9 animal species (the Pacific sheath-tailed
bat, Slevin's skink, the Mariana eight-spot butterfly, the Guam tree
snail, the humped tree snail, Langford's tree snail, and the fragile
tree snail) addressed in this final rule (Table 3) (Stone 1970, pp. 14,
32; Perlman and Wood 1994, pp. 135-136.; Fritts and Rodda 1998, pp.
130-133; Mueller-Dombois and Fosberg 1998, p. 250; Perry and Morton
1999, pp. 126-127; Wiles and Johnson 2004, p. 586; Vogt and Williams
2004, pp. 82-89; Berger et al. 2005, pp. 42, 44, 138, 156-157; CNMI-
SWARS 2010, pp. 7, 24; Pratt 2011, pp. 2, 36; Cook 2012, in litt.;
Rogers 2012, in litt.; Rubinoff and Haines 2012, in litt.; Gawel 2014,
in litt.; Marler 2014, in litt.). The three epiphytic orchids
(Bulbophyllum guamense, Dendrobium guamense, and Tuberolabium
guamense), the vine Tinospora homosepala, the Mariana wandering
butterfly and its host plant Maytenus thompsonii, and the Rota blue
damselfly are not reported to be vulnerable to habitat modification and
destruction caused by nonnative ungulates.
Pigs--The destruction or degradation of habitat due to nonnative
feral pigs is currently a threat in 2 (forest and savanna) of the 4
Mariana Islands ecosystems and their associated species on 4 of the 15
islands (Guam, Alamagan, Pagan, and Agrihan) (Berger et al. 2005, pp.
37-38, 40-44, 51, 95, 114; CNMI-SWARS 2010, p. 15; Kessler 2011, pp.
320, 323; Pratt 2011, pp. 2, 36). Pigs are present on other islands in
the archipelago not noted above (i.e., Rota, Saipan, and Tinian);
however, they are present in very low numbers, primarily on farms and,
therefore, not considered a threat on these islands at this time.
Feral pigs are known to cause deleterious impacts to ecosystem
processes and functions throughout their worldwide distribution (Aplet
et al. 1991, p. 56; Anderson and Stone 1993, p. 201; Campbell and Long
2009, p. 2,319). Feral pigs are extremely destructive and have both
direct and indirect impacts on native plant communities. While rooting
in the earth in search of invertebrates and plant material, pigs
directly impact native plants by disturbing and destroying vegetative
cover, and trampling plants and seedlings. It has been estimated that
at a conservative rooting rate of 2 square yards (yd\2\) (1.7 m\2\) per
minute, with only 4 hours of foraging a day, a single pig could disturb
more than 1,600 yd\2\ (1,340 m\2\) (or approximately 0.3 ac, or 0.1 ha)
of groundcover per week (Anderson et al. 2007, in litt.). Pigs may also
reduce or eliminate plant regeneration by damaging or eating seeds and
seedlings (further discussion of predation by nonnative ungulates is
provided under ``Factor C. Disease and Predation,'' below). Pigs are a
major vector for the establishment and spread of competing invasive,
nonnative plant species by dispersing plant seeds on their hooves and
fur, and in their feces (Diong 1982, pp. 169-170, 196-197), which also
serves to fertilize disturbed soil (Siemann et al. 2009, p. 547). In
addition, pig rooting and wallowing contributes to erosion by clearing
vegetation and creating large areas of disturbed soil, especially on
slopes (Smith 1985, pp. 190, 192, 196, 200, 204, 230-231; Stone 1985,
pp. 254-255, 262-264; Tomich 1986, pp. 120-126; Cuddihy and Stone 1990,
pp. 64-65; Aplet et al. 1991, p. 56; Loope et al. 1991, pp. 18-19;
Gagne and Cuddihy 1999, p. 52; Nogueira-Filho et al. 2009, p. 3,681;
CNMI-SWARS 2010, p. 15; Dunkell et al. 2011, pp. 175-177; Kessler 2011,
pp. 320, 323). Erosion, resulting from rooting and trampling by pigs,
impacts native plant communities by contributing to watershed
degradation and alteration of plant nutrient status, as well as causing
direct
[[Page 59454]]
damage to individual plants from landslides (Berger et al. 2005, pp.
42-44; Vitousek et al. 2009, pp. 3,074-3,086; Chan-Halbrendt et al.
2010, p. 251; Kessler 2011, pp. 320-324).
In the Hawaiian Islands, pigs have been described as the most
pervasive and disruptive nonnative influence on the unique native
forests, and are widely recognized as one of the greatest current
threats to Hawaii's forest ecosystems (Aplet et al. 1991, p. 56;
Anderson and Stone 1993, p. 195). The negative impacts from pig rooting
and wallowing described above negatively affects 2 of the 4 described
ecosystems (forest and savanna), and 14 of the 23 species (9 plants:
Cycas micronesica, Hedyotis megalantha, Heritiera longipetiolata, Maesa
walkeri, Nervilia jacksoniae, Phyllanthus saffordii, Psychotria
malaspinae, Solanum guamense, and Tabernaemontana rotensis; and 5
animals: Slevin's skink, the Mariana eight-spot butterfly, and the Guam
tree snail, the humped tree snail, and the fragile tree snail) listed
as endangered or threatened species in this final rule (Conry 1988, pp.
27-28; Vogt and Williams 2004, p. 88; Berger et al. 2005, pp. 37-38,
40-44, 51, 95, 114; CNMI-SWARS 2010, p. 15; SWCA Environmental
Consultants (SWCA) 2010, p. 38; Kessler 2011, pp. 320, 323; Pratt 2011,
pp. 2, 36; Harrington et al. 2012, in litt.).
Goats--Habitat destruction or degradation of habitat due to
nonnative feral goats is currently a threat to three of the species
addressed in this final rule in two (forest and cave) of the four
Mariana Islands ecosystems, on the islands of Aguiguan, Alamagan,
Pagan, and Agrihan (Berger et al. 2005, pp. 36, 38, 40, 42-47; CNMI-
SWARS 2010, p. 15; Kessler 2011, pp. 320-323; Pratt 2011, pp. 2, 36).
Goats are presumably present on other islands (e.g., Guam and Saipan,
and possibly Rota), but these individuals are primarily on farms and,
therefore, are not considered a threat at this time (Kremer 2013, in
litt.). Three of the 23 species listed as endangered or threatened
species in this rule (the Pacific sheath-tailed bat, the humped tree
snail, and Langford's tree snail), within the forest and cave
ecosystems on the above-mentioned islands, are negatively affected by
feral goats.
The feral goat population on Aguiguan increased from a handful of
animals in 1992 to more than 1,000 in 2002, which led to the general
destruction of the forest ecosystem due to lack of regeneration of
native plants and almost complete loss of understory plants, leaving
only two native plants that are unpalatable, Cynometra ramiflora and
Meiogyne cylindrocarpa (Wiles and Worthington 2002, p. 7; Cruz et al.
2008, p. 243). In addition, feral goats on Aguiguan have been observed
entering caves for shelter, which disrupts the endangered Mariana
swiftlet colonies and is believed to disturb the Pacific sheath-tailed
bat (Wiles and Worthington 2002, p. 17; Cruz et al. 2008, p. 243).
Researchers found that if caves suitable for bats were occupied by
goats, there were no bats present in the caves (GDAWR 1995, p. 95).
Goats are widely recognized to have almost limitless ranges, and are
able to access, and forage in, extremely rugged terrain (Clarke and
Cuddihy 1980, pp. C-19, C-20; Culliney 1988, p. 336; Cuddihy and Stone
1990, p. 64).
Goats have completely eliminated some plant species from islands
(Mueller-Dombois and Fosberg 1998, p. 250; Atkinson and Atkinson 2000,
p. 21). Goat browsing negatively impacts the habitat that supports the
humped tree snail (on Aguiguan, Alamagan, and Pagan), and the fragile
tree snail and Langford's tree snail (on Aguiguan) in the forest
ecosystem by altering the essential microclimate, leading to increased
desiccation and disruption of plant decay processes (Mueller-Dombois
and Fosberg 1998, p. 250). On Agrihan, goats have destroyed much of the
shrubs that make up the subcanopy, and the herbs in the understory
(Ohba 1994, p. 19). In addition, goats eat the seeds and seedlings of
one of the dominant Micronesian (Mariana Islands and Palau) endemic
canopy species, Elaeocarpus joga, preventing its regeneration (Ohba
1994, p. 19; Ritter and Naugle 1999, pp. 275-281). None of the 23
species addressed in this final rule are known to currently occur on
Agrihan; however, this island may be involved in future recovery
efforts for 1 or more of the 23 species, and 2 other listed species,
the Mariana fruit bat (Pteropus mariannus mariannus) and the
Micronesian megapode (Megapodius laperouse), occur there.
Cattle--Habitat destruction or degradation of habitat by feral
cattle is currently a threat to one species addressed in this final
rule (the humped tree snail) in the forest ecosystem on the islands of
Alamagan and Pagan (Berger et al. 2005, pp. 114, 218; Kessler 2011, p.
320). Cattle grazing damages the native vegetation and contributes to
loss of native plant species, and also alters the essential
microclimate leading to increased desiccation and disruption of plant
decay processes necessary to support the humped tree snail, which
currently occurs on the islands of Alamagan and Pagan (Mueller-Dombois
and Fosberg 1998, p. 261; Pratt 2011, pp. 2, 36; Hadfield 2010, 23 pp.;
Berger et al. 2005, pp. 114, 218). Feral cattle eat native vegetation,
trample roots and seedlings, cause erosion, create disturbed areas into
which alien plants invade, and spread seeds of alien plants in their
feces and on their bodies. The forest in areas grazed by cattle
degrades to grassland pasture, and plant cover is reduced for many
years following removal of cattle from an area. Feral cattle have also
roamed the island of Tinian for centuries and are reported to have
negatively affected habitat across the island by grazing, trampling
plants, and exposing soil, thereby changing the microclimate and
composition of vegetation (Wiles et al. 1990, pp. 167-180; Natural
Resources Conservation Service (NRCS) 2015, in litt.).
At present the number of feral cattle on Tinian is very low, and we
do not consider feral cattle to currently pose a significant threat to
the two species that occur on the island (the plant Heritiera
longipetiolata, and the humped tree snail). However, cattle ranching is
gaining in popularity, and in the future the number of cattle is
expected to double from 1,500 individuals (Bagnol 2014, in litt.; NRCS
2015, in litt.). The number of cattle ranchers on Tinian has risen from
10 or 12 in 2010, to 49 ranchers by 2014 (Bagnol 2014, in litt.). As
numbers of cattle and ranchers increase on Tinian, there may be a
somewhat greater risk of cattle potentially escaping and becoming
feral. Both feral and domestic cattle can drastically alter the
landscape (Wiles et al. pp. 176-177), and depending on the location and
amount of land designated as pasture land for domestic cattle, negative
impacts to the forest ecosystem may be observed in the future. The
Pacific sheath-tailed bat, and the plants Dendrobium guamense, Solanum
guamense, and Tuberolabium guamense, occurred historically on Tinian.
Water buffalo--Several herds of Asiatic water buffalo or carabao
roam southern Guam and the Naval Magazine area, and cause damage to the
forest and savanna ecosystems that support 10 of the 23 species listed
as endangered or threatened species (6 plants: Cycas micronesica,
Heritiera longipetiolata, Maesa walkeri, Nervilia jacksoniae,
Psychotria malaspinae, and Tabernaemontana rotensis; 4 animals: The
Mariana eight-spot butterfly, the Guam tree snail, the humped tree
snail, and the fragile tree snail) (Conry 1988, pp. 27-28; Harrington
et al. 2012, in litt.). Water buffalo create mud wallows and trample
vegetation (Conry 1988, p. 27). Wallowing pools can cover as much as
0.3 ac (0.1 ha) and reach a depth of 3 ft (1.0 m) (Conry 1988, p. 27),
and
[[Page 59455]]
trampling denudes land cover, leaving erosion scars and slumping (Conry
1988, pp. 27-28). Water buffalo negatively impact the Mariana eight-
spot butterfly by damaging the habitat that supports its two host
plants (Procris pendunculata and Elatostema calcareum). Although four
additional species (the three epiphytic orchids (Bulbophyllum guamense,
Dendrobium guamense, and Tuberolabium guamense), and the Mariana
wandering butterfly and its host plant Maytenus thompsonii) may occur
on the Naval Magazine, these four species are not as vulnerable to the
negative impacts associated with water buffalo.
Deer--Habitat destruction or degradation due to Philippine deer is
currently a threat to 13 of the 23 species found in 2 of the 4
described Mariana Island ecosystems (forest and savanna) on the islands
of Guam and Rota (Wiles et al. 1999, pp. 198-200). Philippine deer have
caused extensive damage resulting in changes in the forest structure,
including erosion, grazing to the point of clearing the entire
herbaceous understory, consumption of seeds and seedlings preventing
regeneration of native plants and the spread of invasive plant species,
and other physical damage (e.g., trunk rubbing) (Schreiner 1997, pp.
179-180; Wiles et al.1999, pp. 193-215; Berger et al. 2005, pp. 36, 45-
46, 100; CNMI-SWARS 2010, p. 24; JGPO-NavFac, Pacific 2010b, p. 3-33;
SWCA 2011, pp. 35, 42; Harrington et al. 2012, in litt.). At least 34
native plant species in the forest ecosystem have been documented as
known food of the deer on the islands of Guam and Rota, including: (1)
Genera of 5 plant species addressed in this final rule (Cycas spp.
(e.g., C. micronesica), Eugenia spp. (e.g., E. bryanii), Heritiera spp.
(e.g., H. longipetiolata), Psychotria spp. (e.g., P. malaspinae), and
Solanum spp. (e.g., S. guamense); and genera of the 2 host plants,
Procris spp. and Elatostema spp., that support the Mariana eight-spot
butterfly; (2) several keystone ecosystem species: Artocarpus
mariannensis (dokdok, seeded bread fruit), Discocalyx megacarpa (otot),
Merrilliodendron megacarpum (faniok), Piper spp., Pipturus argenteus,
and Premna obtusifolia (false elder); and (3) the listed plant species
Serianthes nelsonii (Wiles et al. 1999, pp. 198-200, 203; Rubinoff and
Haines 2012, in litt.). Philippine deer degrade the habitats that
support 12 of the 23 species listed as endangered or threatened species
in this final rule, in the forest and savanna ecosystems on the islands
of Guam and Rota (8 plants: Cycas micronesica, Eugenia bryanii,
Heritiera longipetiolata, Maesa walkeri, Nervilia jacksoniae,
Psychotria malaspinae, Solanum guamense, and Tabernaemontana rotensis;
and 4 animals: The Mariana eight-spot butterfly (including the two host
plants Procris pendunculata and Elatostema calcareum), the Guam tree
snail, the humped tree snail, and the fragile tree snail).
In summary, the habitats for 17 of the 23 species within all 4
ecosystems (forest, savanna, stream, and cave) identified in this rule
are exposed to ongoing destruction and modification by feral ungulates
(pigs, goats, cattle, and water buffalo), and Philippine deer (10
plants: Cycas micronesica, Eugenia bryanii, Hedyotis megalantha,
Heritiera longipetiolata, Maesa walkeri, Nervilia jacksoniae,
Phyllanthus saffordii, Psychotria malaspinae, Solanum guamense, and
Tabernaemontana rotensis; and 7 animals: The Pacific sheath-tailed bat,
Slevin's skink, the Mariana eight-spot butterfly (and its two host
plants Procris pendunculata and Elatostema calcareum), the Guam tree
snail, the humped tree snail, Langford's tree snail, and the fragile
tree snail). The effects of these nonnative animals include: (1) The
destruction of vegetative cover and the required microclimate of the 4
tree snails, (2) trampling of plants and seedlings and direct
consumption of native vegetation and the 10 plants, as well as the host
plants for the 2 butterflies, (3) altering the native ecosystems that
provide habitat for the 10 plants and 7 animals by soil disturbance
leading to erosion and sedimentation, (4) dispersal of alien plant
seeds on hooves and coats and in feces, which contributes to invasion
and alteration of ecosystems required by the 10 plants and 7 animals,
(5) alteration of soil nitrogen availability, and creation of open
areas conducive to further invasion of native ecosystems by nonnative
pest plant species, and (6) alteration of food availability for the
Pacific sheath-tailed bat by destruction of native forest and the
associated insect prey. All of these impacts lead to the subsequent
conversion of a plant community dominated by native species to one
dominated by nonnative species (see ``Habitat Destruction and
Modification by Nonnative Plants,'' below). In addition, because these
nonnative animals inhabit terrain that is often steep and rugged
(Cuddihy and Stone 1990, pp. 64-65; Berger et al. 2005, pp. 36-38, 40-
47, 51, 95, 100, 114, 218), foraging and trampling contribute to severe
erosion of watersheds. Nonnative ungulates would thus pose a potential
threat to the Rota blue damselfly's stream habitat, if these ungulates
were allowed to roam freely on Rota (Dunkell et al. 2011, p. 192).
Habitat Destruction and Modification by Introduced Small Vertebrates
Rats--There are three rat species found in the Mariana Islands: (1)
The Polynesian rat (Rattus exulans), the only rat found in prehistoric
fossil records; (2) the Norway rat (R. norvegicus); and (3) a putative
new southeast Asian Rattus species, originally thought to be R. diardii
(synonymous with R. tanezumi) (Kuroda 1938 in Wiewel et al. 2009, p.
208; Wiewel et al. 2009, pp. 210, 214-216; Pages et al. 2010, p. 200;
Pages et al. 2013, pp. 1,019-1,020). One or more of these rat species
are present on all 15 Mariana Islands (Wiewel et al. 2009, pp. 205-222;
Kessler 2011, p. 320). Rats are a threat to the forest and savanna
ecosystems that support 22 of the 23 species listed as endangered or
threatened in this final rule (all 14 plant species and 8 of 9 animal
species--all except the Rota blue damselfly in the stream ecosystem),
by affecting regeneration of native vegetation, thereby destroying or
eliminating the associated flora and fauna of these ecosystems.
Rats are recognized as one of the most destructive invasive
vertebrates, causing significant ecological, economic, and health
impacts (Cuddihy and Stone 1990, pp. 68-69; Atkinson and Atkinson 2000,
pp. 23-24). Rats impact native plants by eating fleshy fruits, seeds,
flowers, stems, leaves, roots, and other plant parts (Atkinson and
Atkinson 2000, p. 23), and can seriously affect plant regeneration. A
New Zealand study of rats in native forests has demonstrated that, over
time, differential regeneration of plants, as a consequence of rat
predation, may alter the species composition of forested areas (Cuddihy
and Stone 1990, p. 69). Rats have caused declines or even the complete
elimination of island plant species (Campbell and Atkinson 1999, in
Atkinson and Atkinson 2000, p. 24). Plants with fleshy fruits are
particularly susceptible to rat predation (Stone 1985, p. 264; Cuddihy
and Stone 1990, pp. 67-69).
Rats also impact the faunal composition of ecosystems by predation
or competition with native amphibian, avian, invertebrate, mammalian,
and reptilian species, often resulting in population declines or even
extirpations; disruption of island trophic systems including nutrient
cycling; and by the creation of novel vectors and reservoirs for
diseases and parasites (Pickering and Norris 1996 in Wiewel et al.
2009, p. 205; Chanteau et
[[Page 59456]]
al. 1998 in Wiewel et al. 2009, p. 205; Fukami et al. 2006, pp. 1,302-
1,303; Towns et al. 2006, pp. 876-877; Wiewel et al. 2009, p. 205).
Rats are less numerous on Guam compared to Rota, Saipan, and
Tinian, due to the presence of the brown treesnake (see ``Brown
Treesnake,'' below) (Wiewel et al. 2009, p. 210). An inverse
relationship has been observed between rat density and the density of
the brown treesnake, as rats are a food source and, therefore,
contribute toward the brown treesnake's persistence (Rodda and Savidge
2007, p. 315; Wiewel et al. 2009, p. 218). Rodda et al. (1991, in
Berger et al. 2005, p. 175) suggests that rats negatively impact native
reptile populations, such as Slevin's skink, by aggressively competing
for habitat. Several restoration studies have shown rapid increases in
skink populations after removal of rats (Towns et al. 2001, pp. 6, 9).
Brown treesnake--The brown treesnake, native to coastal eastern
Australia and north through Papua New Guinea and Melanesia, was
accidentally introduced to Guam shortly after World War II (Rodda and
Savidge 2007, p. 307). This arboreal, nocturnal snake was first
observed near the Fena Reservoir in the Santa Rita area, and now
occupies all ecosystems on Guam (Rodda and Savidge 2007, p. 314). There
are reported sightings of the brown treesnake on Saipan; however, there
are no known established populations on Saipan at this time (Campbell
2014, pers. comm.; Phillips 2014, pers. comm.). On September 3, 2014, a
brown treesnake was captured in a snake trap along the Rota Seaport
fence line promptly initiating extensive island-wide surveys that did
not detect any others (Phillips 2015, in litt.). The brown treesnake is
believed responsible for the extirpation of 13 of Guam's 22 native bird
species (including all but 1 of its native forest bird species), and
for contributing to the elimination of the Mariana fruit bat, the
Pacific sheath-tailed bat, and Slevin's skink populations from the
island (Rodda and Savidge 2007, p. 307).
The loss or severe reduction of so many bird species and other
small native animal species on Guam has ecosystem-wide impacts, since
many of these bird and small animal species were responsible for seed
dispersal and pollination of native plants (Perry and Morton 1999, p.
137; Rodda and Savidge 2007, p. 311; Rogers 2008, in litt.; Rogers
2011, pp. 1-75). Some report that the brown treesnake has eliminated
virtually all native seed dispersers (Fritts and Rodda 1998, p. 129).
Field studies have demonstrated that seed dispersal of selected native
plant species (Aglaia mariannensis, Elaeocarpus joga, and Premna
obtusifolia) have declined on Guam as compared to neighboring islands
(Rota, Saipan, and Tinian), due to brown treesnake predation on native
birds and other small native vertebrate species (Ritter and Naugle
1999, pp. 275-281; Rogers 2008, in litt.; Rogers 2009, in litt.; Rogers
2011, pp. 1-75). Almost three quarters of the native tree species on
Guam were once dependent on birds to eat their fruits and disperse
their seeds (Rogers 2009, in litt.; Rogers 2011, pp. 1-75). Detailed
studies on the native tree P. obtusifolia show that seeds handled by
birds are twice as likely to germinate than seeds that fall off the
tree and land directly below on the forest floor (by either simply
nicking the seed and dropping it, or fully digesting the outer seed
coat and excreting it in feces) (Rogers 2009, in litt.; Rogers 2011,
pp. 1-75). An impact at one trophic level (elimination of seed
dispersers) has cascading effects on other trophic levels, and can
affect ecosystem stability (Perry and Morton 1999, p. 137).
The brown treesnake's elimination of native plant seed dispersers
is an indirect threat that negatively impacts 2 of the 4 described
ecosystems (forest and savanna), and the habitat of 18 of the 23
species (all 14 plant species and 4 of the 9 animal species, including
the Mariana eight-spot butterfly, the Guam tree snail, the humped tree
snail, and the fragile tree snail) listed as endangered or threatened
in this final rule.
Habitat Destruction and Modification by Nonnative Plants
Native vegetation on the Mariana Islands has undergone extreme
alteration because of past and present land management practices,
including ranching, the deliberate introduction of nonnative plants and
animals, agricultural development, military actions, and war (Ohba
1994, pp. 17, 28, 54-69; Mueller-Dombois and Fosberg 1998, p. 242;
Berger et al. 2005, pp. 45, 105, 110, 218, 347, 350; CNMI-SWARS 2010,
pp. 7, 9, 13, 16). Some nonnative plants were brought to the Mariana
Islands by various groups of people, including the Chamorro, for food
or cultural reasons.
The native flora of the Mariana Islands (plant species that were
present before humans arrived) consisted of no more than 500 taxa, 10
percent of which were endemic (species that occur only in the Mariana
Islands). Over 100 plant taxa have been introduced from elsewhere, and
at least one third of these have become pests (i.e., injurious plants)
(Stone 1970, pp. 18-21; Mueller-Dombois and Fosberg 1998, pp. 242-243,
249, 262-263; Costion and Lorence 2012, pp. 51-100). Of these
approximately 30 nonnative pest plant species, at least 9 have altered
the habitat of 20 of the 23 species listed as endangered or threatened
species in this final rule (only 3 of the animal species, the Pacific
sheath-tailed bat, the Slevin's skink, and the Mariana wandering
butterfly, are not directly impacted by nonnative plants (see Table
3)).
Nonnative plants degrade native habitat in the Mariana Islands by:
(1) Modifying the availability of light through alterations of the
canopy structure; (2) altering soil-water regimes; (3) modifying
nutrient cycling; (4) altering the fire regime affecting native plant
communities (e.g., successive fires that burn farther and farther into
native habitat, destroying native plants and removing habitat for
native species by altering microclimatic conditions to favor alien
species); and (5) ultimately converting native-dominated plant
communities to nonnative plant communities (Smith 1985, pp. 217-218;
Cuddihy and Stone, 1990, p. 74; Matson 1990, p. 245; D'Antonio and
Vitousek 1992, p. 73; Ohba 1994, pp. 17, 28, 54-69; Vitousek et al.
1997, pp. 6-9; Mueller-Dombois and Fosberg 1998, pp. 242-243, 249, 262-
263; Berger et al. 2005, pp. 45, 105, 110, 218, 347, 350; CNMI-SWARS
2010, pp. 7, 9, 13, 16).
The following list provides a brief description of the nonnative
plants that impose the greatest negative impacts to forest, savanna,
and stream ecosystems and the species addressed in this final rule that
depend on these ecosystems (all 14 of the plant species and 6 of the
animal species, including the Mariana eight-spot butterfly, Rota blue
damselfly, humped tree snail, Langford's tree snail, Guam tree snail,
and fragile tree snail).
Antigonon leptopus (chain of hearts, Mexican creeper,
coral vine), a perennial vine native to Mexico, has become widespread
throughout the Mariana Islands. This species is a fast-growing,
climbing vine that can reach up to 25 ft (8 m) in length, and smothers
all native plants in its path (University of Florida Center for Aquatic
and Invasive Plants (UF) 2014, in litt.). The fact that this species
can tolerate poor soil and a wide range of light conditions makes this
species a very successful invasive plant (UF 2013, in litt.).
Coccinia grandis (ivy or scarlet gourd), native throughout
Africa and Asia, is an aggressive noxious pantropical weedy vine that
forms dense blankets that smother vegetation,
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and currently proliferates on Guam and Saipan (Space and Falanruw 1999,
pp. 3, 9-10). This species is considered the most invasive and serious
threat to forest health by the CNMI DFW (CNMI-SWARS 2010, p. 15).
Currently, C. grandis covers nearly 80 percent of Saipan (CNMI-SWARS
2010, p. 15).
Chromolaena odorata (Siam weed, bitterbrush, masigsig),
native to Central and South America, is an herbaceous perennial that
forms dense tangled bushes up to 6 ft (2 m) in height, but can grow up
to 20 ft (6 m) as a climber on other plants (Invasive Species
Specialist Group (ISSG)-Global Invasive Species Database (GISD) 2006,
in litt.). This species can grow in a wide range of soils and
vegetation types, giving it an advantage over native plants (ISSG-GISD
2006, in litt.). Dense stands of C. odorata prevent the establishment
of native plant species due to competition and allelopathic (growth
inhibition) effects (ISSG-GISD 2006, in litt.).
Lantana camara (lantana), a malodorous, branched shrub up
to 10 ft (3 m) tall, was brought to the Mariana Islands as an
ornamental plant. Lantana is aggressive, thorny, and forms thickets,
crowding out and preventing the establishment of native plants (Davis
et al. 1992, p. 412; Wagner et al. 1999, p. 1,320).
Leucaena leucocephala (tangantangan, koa haole), a shrub
native to the neotropics, is a nitrogen-fixer and an aggressive
competitor that often forms the dominant element of the vegetation
(Geesink et al. 1999, pp. 679-680).
Paspalum conjugatum (Hilo grass, sour grass) is a
perennial grass that occurs in wet habitats and forms a dense ground
cover. Its small, hairy seeds are easily transported on humans and
animals, or are carried by the wind through native forests, where it
establishes and displaces native vegetation (Pace et al. 2000, p. 23;
Motooka et al. 2003; Pacific Island Ecosytems at Risk (PIER) 2008).
Pennisetum species are aggressive colonizers that
outcompete most native species by forming widespread, dense, thick
mats. Pennisetum setaceum (fountain grass) has been introduced to Guam
(Space and Falanruw 1999, pp. 3, 5). Fountain grass occurs in dry, open
places; barren lava flows; and cinder fields, is fire-adapted, and
burns swiftly and hot, causing extensive damage to the surrounding
habitat (O'Connor 1999, p. 1,581). On Hawaii Island, fountain grass is
estimated to cover hundreds of thousands of acres and has the ability
to become the dominant component in dry, open places in the Mariana
Islands (O'Connor 1999, p. 1,578; Fox 2011, in litt.). Pennisetum
purpureum and P. polystachyon have been introduced to Guam and Saipan
(Space and Falanruw 1999, pp. 3, 5). Pennisetum purpureum (Napier
grass, elephant grass) is a vigorous grass that produces razor-sharp
leaves and forms thick clumps up to 13 ft (4 m) that resemble bamboo
(Plantwise 2014, in litt.). Tall, dense thickets of P. purpureum
outcompete and smother native plants, and can dominate fire-adapted
grassland communities (Holm et al. 1979, in Plantwise 2014, in litt.).
Similarly, dense thickets of Pennisetum polystachyon (mission grass)
alter the fire regime and outcompete and smother native plants
(University of Queensland 2011, in litt.).
Triphasia trifolia (limeberry, limoncito), a shade-
tolerant woody shrub native to southeast Asia, Malaysia, and the
Christmas Islands, is an aggressive plant that forms dense, spiny
thickets in the forest understory that smother native plant species and
outcompetes them for light and water (Commonwealth Agricultural Bureau
International (CABI) 2014--Invasive Species Compendium Online
Database).
Vitex parviflora (small-leaved vitex; molave tree,
agalondi), a medium-sized tree up to 35 ft (10 m) native to Indonesia,
Malaysia, and the Philippines, often forms monotypic stands, and can
spread by seeds and pieces of roots and stems. Vitex parviflora forms
thickets that outcompete, prevent recruitment of, and exclude native
plants (Guaminsects 2005, in litt.). Vitex parviflora has greatly
altered native habitats on Guam (SWCA 2010, p. 36, 67), and is one of
the most dominant trees on the island (Water and Environmental Research
Institute-Island Research and Education Initiative (WERI-IREI) 2014b,
in litt.).
Habitat Destruction and Modification by Fire
Fire is a human-exacerbated threat to native species and native
ecosystems throughout the Mariana Islands, particularly on the island
of Guam. Wildfires plague forest and savanna areas on Guam every dry
season despite the island's humid climate, with at least 80 percent of
wildfires resulting from arson (JGPO-NavFac, Pacific 2010b, p. 1-9).
Deer hunters on Guam and Rota frequently create fires in order to lure
deer to new growth for easier hunting (Boland 2014, in litt.; Kremer
2014, in litt.). It is not uncommon for these fires to become wildfires
that spread across large expanses of the savanna ecosystem as well as
into the adjacent forest ecosystem. Between 1979 and 2001, more than
750 fires were reported annually on Guam, burning more than 155 mi\2\
(401 km\2\) during this time period (JGPO-NavFac, Pacific 2010b, p. 1-
8). Six of these 750 fires burned more than 1,000 ac (405 hectares
(ha)) (JGPO-NavFac, Pacific 2010b, p. 1-8). On the island of Rota,
fires are often set on the Sabana by hunters, which burn into adjacent
native forest.
Fire can destroy dormant seeds of native species as well as plants
themselves, even in steep or inaccessible areas. Successive fires that
burn farther and farther into native habitat destroy native plants and
remove habitat for native species by altering microclimate conditions
to those favorable to alien plants. Alien plant species most likely to
be spread as a consequence of fire are those that produce a high fuel
load, are adapted to survive and regenerate after fire, and establish
rapidly in newly burned areas. Grasses (particularly those that produce
mats of dry material or retain a mass of standing dead leaves) that
invade native forests and shrublands provide fuels that allow fire to
burn areas that would not otherwise easily burn (Fujioka and Fujii 1980
in Cuddihy and Stone 1990, p. 93; D'Antonio and Vitousek 1992, pp. 70,
73-74; Tunison et al. 2002, p. 122). Native woody plants may recover
from fire to some degree, but fire shifts the competitive balance
toward alien species (National Park Service (NPS) 1989 in Cuddihy and
Stone 1990, p. 93). Another factor that contributes to wildfires on
Guam, and other Mariana Islands with nonnative ungulates, includes land
clearing for pasturage and ranching, which results in fire-prone areas
of nonnative grasses and shrubs (Stone 1970, p. 32; CNMI-SWARS 2010,
pp. 7, 20). Further, the danger of fire increases following intense
typhoons, due to large fuel accumulation (Donnelly 2010, p. 6).
Wildfire is a threat to nine plant species (Bulbophyllum guamense,
Cycas micronesica, Dendrobium guamense, Hedyotis megalantha, Maesa
walkeri, Nervilia jacksoniae, Phyllanthus saffordii, Tabernaemontana
rotensis, and Tuberolabium guamense) and two animal species (the Guam
tree snail (Guam) and the humped tree snail (Guam and Rota)), because
individuals of these species occur in the savanna ecosystem or the
forest ecosystem adjacent to the savanna ecosystem, on southern Guam
(i.e., Cetti Watershed area) and on the Rota Sabana, where fires are
common (Grimm 2012, in litt.; Gutierrez 2012, in litt.; Gutierrez 2013,
in litt.).
[[Page 59458]]
Habitat Destruction and Modification by Typhoons
The Mariana Islands lie in the western North Pacific basin, which
is the world's most prolific typhoon basin, with an annual average of
26 named tropical cyclones between 1951 and 2010, depending on the
database used (Keener et al. 2012, p. 50). Typhoons are seasonal,
occurring more often in the summer, and tend to be more intense during
El Ni[ntilde]o years (Gualdi et al. 2008, pp. 5,205, 5,208, 5,226). In
May 2015, Typhoon Dolphin passed between Guam and Rota, initiating a
disaster declaration by the Federal Emergency Management Agency (FEMA)
for Guam and by the CNMI Governor for the island of Rota (FEMA 2015a,
in litt.). Then, in August 2015, Typhoon Soudelor slammed directly into
Saipan destroying buildings and downing trees and power lines, thus
initiating a second major disaster declaration for the Mariana Islands
this year (FEMA 2015b, in litt.). Additionally, in 2013, one of the
strongest typhoons ever recorded (Typhoon Haiyan) passed just south of
the Marianas and struck the Philippines. Between 2002 and 2005, three
typhoons (Typhoon Chataan (2002), Typhoon Tingting (2004), and Typhoon
Nabi (2005)) and two super typhoons (Super Typhoon Pongsona (2002) and
Super Typhoon Chaba (2004)) struck the Mariana Islands (FEMA 2014, in
litt.). In the previous 20 years (between 1976 and 1997), only eight
typhoons reached the island chain that caused damage warranting FEMA
assistance (FEMA 2014, in litt.).
Typhoons may cause destruction of native vegetation and open the
native canopy, thus modifying the availability of light, and creating
disturbed areas conducive to invasion by nonnative pest species and
nonnative plant species that compete for space, water, and nutrients,
and alter basic water and nutrient cycling processes. This process
leads to decreased growth and reproduction for all 14 plant species
addressed in this final rule (see Table 3, above), and for the host
plants (Procris pendunculata, Elatostema calcareum, and Maytenus
thompsonii) for the 2 butterfly species (Perlman 1992, 9 pp.; Kitayama
and Mueller-Dombois 1995, p. 671). Additionally, typhoons initiate a
large pulse in the accumulation of debris and often trigger landslides
with large debris flows (Lugo 2008, pp. 368, 372), as well as induce
defoliation and wind-thrown trees, which can create conditions
favorable to wildfires or result in the direct damage or destruction of
individuals of the 14 plant species addressed in this final rule.
Further, typhoon frequency globally may decrease; however, there may be
some regional increases (e.g., in the western north Pacific), with an
increase in the frequency of higher intensity events due to climate
change (Emanuel et al. 2008, p. 361).
Typhoons are a natural occurrence in the Pacific Islands, and the
native species here have coevolved with such natural disturbances.
However, when species have become greatly reduced in numbers or
distribution due to other factors, even a natural disturbance can
constitute a significant threat, and can result in local extirpation or
even extinction. Typhoons pose a threat to the nine animal species
listed as endangered species in this rule, because the associated high
winds may dislodge larvae, juveniles, or adult individuals from their
host plants, caves, or streams, thereby increasing the likelihood of
mortality caused by lack of essential nutrients for proper development;
increase their exposure to predators (e.g., rats, brown treesnake,
monitor lizards, ants) (see ``Factor C. Disease and Predation,''
below); destroy host plants; open up the canopy and alter the
microclimate; or cause direct physical damage or mortality. Damage by
subsequent typhoons could further decrease the remaining native plant-
dominated habitat areas, and the associated food resources, that
support the nine animal species. For plant and animal species that
persist only in low numbers and restricted ranges, such as the 23
Mariana Islands species addressed here, natural disasters, such as
typhoons, can be particularly devastating (Mitchell et al. 2005, p. 4-
3). Although typhoons would not normally be considered a threat to
native species, in cases such as these the species are vulnerable due
to reductions in abundance and range as a consequence of other threat
factors.
Habitat Destruction and Modification by Climate Change
Our analyses under the Act include consideration of ongoing and
projected changes in climate. The terms ``climate'' and ``climate
change'' are defined by the Intergovernmental Panel on Climate Change
(IPCC). ``Climate'' refers to the mean and variability of different
types of weather conditions over time, with 30 years being a typical
period for such measurements, although shorter or longer periods also
may be used (Le Treut et al. 2007, p. 96). The term ``climate change''
thus refers to a change in the mean or variability of one or more
measures of climate (e.g., temperature or precipitation) that persists
for an extended period, typically decades or longer, whether the change
is due to natural variability, human activity, or both (Le Treut et al.
2007, p. 104). Various types of changes in climate can have direct or
indirect effects on species. These effects may be positive, neutral, or
negative, and they may change over time, depending on the species and
other relevant considerations, such as the effects of interactions of
climate with other variables (e.g., habitat fragmentation) (IPCC 2007,
pp. 8-14, 18).
Climate change will be a particular challenge for the conservation
of biodiversity because the introduction and interaction of additional
stressors may push species beyond their ability to survive (Lovejoy
2005, pp. 325-326). The synergistic implications of climate change and
habitat fragmentation are the most threatening facet of climate change
for biodiversity (Hannah et al. 2005, p. 4). The magnitude and
intensity of the impacts of global climate change and increasing
temperatures on native Mariana Island ecosystems are unknown.
Currently, there are no climate change studies that specifically
address impacts to the specific Mariana Island ecosystems discussed
here or any of the 23 individual species addressed in this final rule
that are associated with these ecosystems. There are, however, climate
change studies that address potential changes in the tropical Pacific
on a broader scale. Based on the best available information, climate
change impacts could lead to the loss of native species that comprise
the communities in which the 23 species occur (Pounds et al. 1999, pp.
611-612; Still et al. 1999, p. 610; Benning et al. 2002, pp. 14,246-
14,248; Allen et al. 2010, pp. 668-669; Sturrock et al. 2011, p. 144;
Townsend et al. 2011, pp. 14-15; Warren 2011, pp. 165-166). In
addition, weather regime changes (droughts, floods, typhoons) will
likely result from increased annual average temperatures related to
more frequent El Ni[ntilde]o episodes as hypothesized for other Pacific
Island chains (Giambelluca et al. 1991, p. iii). Future changes in
precipitation and the forecast of those changes are highly uncertain
because they depend, in part, on how the El Ni[ntilde]o-La Ni[ntilde]a
weather cycle (a disruption of the ocean atmospheric system in the
tropical Pacific having important global consequences for weather and
climate) might change (State of Hawaii 1998, p. 2-10). The 23 species
listed as endangered or threatened species in this final rule are
vulnerable to extinction due to anticipated environmental changes that
may result from global climate change,
[[Page 59459]]
due to their small population size and highly restricted ranges.
Environmental changes that are likely to affect these species are
expected to include habitat loss or alteration and changes in
disturbance regimes (e.g., storms and typhoons).
The range of global surface warming since 1979 is 0.29 degrees
Fahrenheit ([deg]F) to 0.32[emsp14][deg]F (0.16 degrees Celsius
([deg]C) to 0.18 [deg]C) per decade (Trenberth et al. 2007, p. 237).
Globally, the annual number of warm nights increased by about 25 days
since 1951, with the greatest increase since the mid-1970s (Alexander
et al. 2006, pp. 7-8). The bulk of the increase in mean temperature is
related to a larger increase in minimum temperatures compared to the
increase in maximum temperatures (Giambelluca et al. 2008, p. 1).
Globally averaged, 2012 ranked as the eighth or ninth warmest year
since records began in the mid- to late 1800s (Lander and Guard 2013,
p. S-11).
To date, climate change indicators specific to the Mariana Islands
have not been published; however, data collected on climate change
indicators from the Pacific Region, (e.g., the Hawaiian Islands) show
that predicted changes associated with increases in temperature
include, but are not limited to, a shift in vegetation zones upslope,
shifts in animal species' ranges, changes in mean precipitation with
unpredictable effects on local environments, increased occurrence of
drought cycles, and increases in the intensity and number of hurricanes
(i.e., typhoons) (Loope and Giambelluca 1998, pp. 514-515; Emanuel et
al. 2008, p. 365; U.S. Global Change Research Program (US-GCRP) 2009,
pp. 145-149, 153; Keener et al. 2010, pp. 25-28; Finucane et al. 2012,
pp. 23-26; Keener et al. 2012, pp. 47-51). It is reasonable to
extrapolate these predictions to the Mariana Islands as climate in this
area is strongly influenced by the phase of the El Ni[ntilde]o Southern
Oscillation (ENSO) (Lander and Guard 2013, pp. S192-S194). In addition,
weather regime changes (e.g., droughts, floods, and typhoons) will
likely result from increased annual average temperatures related to
more frequent El Ni[ntilde]o episodes in the Mariana Islands (Keener et
al. 2012, pp. 35-37, 47-51), and elsewhere in the Pacific (Giambelluca
et al. 1991, p. iii). However, despite considerable progress made by
expert scientists toward understanding the impacts of climate change on
many of the processes that contribute to El Ni[ntilde]o variability, it
is not possible to say whether or not El Ni[ntilde]o activity will be
affected by climate change (Collins et al. 2010, p. 391).
As global surface temperature rises, the evaporation of water vapor
increases, resulting in higher concentrations of water vapor in the
atmosphere, further resulting in altered global precipitation patterns
(U.S. National Science and Technology Council (US-NSTC) 2008, pp. 60-
61; US-GCRP 2009, pp. 145-146). While annual global precipitation has
increased over the last 100 years, the combined effect of increases in
evaporation and evapotranspiration is causing land surface drying in
some regions leading to a greater incidence and severity of drought
(US-NSTC 2008, pp. 60-61; US-GCRP 2009, pp. 145-146). Over the past 100
years, most of the Pacific has experienced an annual decline in
precipitation; however, the western North Pacific (e.g., western
Micronesia, including the Mariana Islands) has experienced a slight
increase (up to 14 percent on some islands) (US-NSTC 2008, p. 63;
Keener et al. 2010, pp. 53-54). Increases in rain are associated with
alterations in faunal breeding systems and increases in disease
prevalence, flooding, and erosion (Easterling et al. 2000, p. 2,073;
Harvell et al. 2002, pp. 2,159-2,161; Nearing et al. 2004, pp. 48-49).
It should be noted that, although the western North Pacific typically
experiences large amounts of rainfall annually, drought is a serious
concern throughout Micronesia due to limited storage capacity and small
groundwater supplies (Keener et al. 2012, pp. 49, 58, 119). Future
changes in precipitation in the Mariana Islands are uncertain because
they depend, in part, on how the El Ni[ntilde]o-La Ni[ntilde]a weather
cycle might change (State of Hawaii 1998, p. 2-10). Long periods of
decline in annual precipitation result in a reduction in moisture
availability, loss of wet forest, an increase in drought frequency, and
a self-perpetuating cycle of invasion by nonnative plants, increasing
fire-cycles, and increasing erosion.
Climate modeling has projected changes in typhoon frequency and
intensity due to global warming over the next 100 to 200 years (Emanuel
et al. 2008, p. 360, Figure 8; Yu et al. 2010, pp. 1,355-1,356, 1,369-
1,370); however, there are no certain climate model predictions for a
change in the duration of Pacific tropical cyclone storm season (which
generally runs from May through November) (Collins et al. 2010, p.
396). A typhoon (as a tropical cyclone is referred to in the Northwest
Pacific ocean) is the generic term for a medium- to large-scale, low-
pressure storm system over tropical or subtropical waters with
organized convection (i.e., thunderstorm activity) and definite
cyclonic surface wind circulation (counterclockwise direction in the
Northern Hemisphere) (Holland 1993, p. 7, National Oceanic and
Atmospheric Administration (NOAA) 2011, in litt.). In the north Pacific
Ocean, west of the International Date Line, once a typhoon reaches an
intensity of winds of at least 150 mi per hour (65 m per second), it is
classified as a super typhoon (Neumann 1993, pp. 1-2; NOAA 2011, in
litt.). The high winds and strong storm surges associated with
typhoons, particularly super typhoons, have periodically caused great
damage to the vegetation of the Mariana Islands.
On a global scale, sea level is rising as a result of thermal
expansion of warming ocean water; the melting of ice sheets, glaciers,
and ice caps; and the addition of water from terrestrial systems
(Climate Institute 2011, in litt.). Sea level rose at an average rate
of 0.1 in (3.1 mm) per year between 1961 and 2003 (IPCC AR4 2007, p.
30), with a predicted increase in 2100 of 1.6 to 4.6 ft (0.5 to 1.4 m)
above the 1990 level (Rahmstorf 2007, p. 368). Seven of the 23 species
(5 plants: Bulbophyllum guamense, Cycas micronesica, Dendrobium
guamense, Heritiera longipetiolata, and Nervilia jacksoniae; and 2
animals: the humped tree snail and the Mariana eight-spot butterfly
(indirectly through impacts to its 2 host plants (Procris pendunculata
and Elatostema calcareum)) have individuals that occur close to the
coast in the adjacent forest ecosystem at or near sea-level and may be
negatively impacted by sea-level rise and coastal inundation due to
climate change; however, there is no specific data available on how
sea-level rise and coastal inundation will impact these species.
In summary, we conclude that the projected effects of climate
change, including increased variability of ambient temperature,
precipitation, typhoons, and sea-level rise and inundation would
provide additional stresses on the 4 ecosystems and each of the 23
associated species because they are highly vulnerable to disturbance
and related invasion of nonnative species, thus exacerbating the
current threats to the species. The risk of extinction as a result of
such factors increases when a species' range is restricted, its habitat
decreases, and its population numbers decline (IPCC 2007, pp. 8-11).
These 23 species face this greater risk of extinction due to the loss
of redundancy and resiliency created by their limited ranges,
restricted habitat requirements, small population sizes, or low numbers
of individuals. We therefore conclude
[[Page 59460]]
these 23 species are vulnerable to the projected environmental impacts
that may result from changes in climate and subsequent impacts to their
habitats (Loope and Giambelluca 1998, pp. 504-505; Pounds et al. 1999,
pp. 611-612; Still et al.1999, p. 610; Benning et al. 2002, pp. 14,246-
14,248; Giambelluca and Luke 2007, pp. 13-15). Even natural stochastic
events such as typhoons pose a heightened risk under such conditions,
since such an event is capable of eliminating all or a significant
proportion of remaining individuals of these species. Based on the
above information, changes in environmental conditions that result from
climate change are likely to negatively impact the 23 species listed as
endangered or threatened species in this rule. The projected effects of
increasing temperature, and other aspects of climate change on the 23
species may be direct, such as physiological stress caused by increased
temperature or lack of moisture, or indirect, such as the modification
or destruction of habitat, increased competition by nonnative species,
and changes in disturbance regimes that lead to changes in habitat
(e.g., fire, increased incidence or intensity of typhoons). The
specific and cumulative effects of climate change on each of these 23
species are presently unknown, but we anticipate that these effects, if
realized, will exacerbate the current threats to these species.
Conservation Efforts To Reduce Habitat Destruction, Modification, or
Curtailment of Its Range
There are no approved Habitat Conservation Plans, Candidate
Conservation Agreements, or Strategic Habitat Areas that specifically
address these 23 species and threats to their habitat.
In 2012, the Guam Plant Extinction Prevention Program (GPEPP) was
formed to address conservation concerns for a select group of native
Mariana Islands plant species, including three of the plant species
addressed in this final rule: Heritiera longipetiolata, Maesa walkeri,
and Psychotria malaspinae. GPEPP is a partnership between the
University of Guam (UOG), multiple Federal agencies (USFWS, DOD, and
USDA), Hawaii State DLNR, and the Hawaii Plant Extinction Prevention
Program (Hawaii PEPP). The goal of GPEPP is to prevent the extinction
of native Mariana Islands plant species that have fewer than 200
individuals remaining in the wild on the island of Guam (GPEPP 2014, in
litt.). The group currently has funding limitations, so they are
focusing their efforts on tree species. The program's main objectives
are to monitor, collect, survey, manage, and reintroduce native plant
species in the Mariana Islands. They plan to work with conservation
partners to protect wild populations and preserve genetic material
(GPEPP 2014, in litt.).
A conservation project on Rota, administered through the Water and
Environmental Research Institute of the Western Pacific at the
University of Guam, is aimed to analyze the island's hydrology, with
the ultimate goal of protection of the Sabana Watershed and Talakhaya
Springs (Keel et al. 2007, pp. 5, 22-23). Erosion control,
revegetation, and water source preservation conducted as part of this
project may provide protection to 9 of the 23 species in this final
rule that currently or historically occurred on the southern side of
the central plateau of Rota (6 plants: Bulbophyllum guamense, Cycas
micronesica, Dendrobium guamense, Maesa walkeri, Nervilia jacksoniae,
Tuberolabium guamense; 3 animals: The Mariana wandering butterfly, the
Rota blue damselfly, and the humped tree snail).
A U.S. Fish and Wildlife Service Biological Opinion (1998)
recommended that the Navy fund conservation and recovery projects in
the Mariana Islands to improve habitat and population sizes of the
federally listed Micronesian megapode as mitigation for bombing
activities on Farallon de Medinilla. This resulted in the removal of
ungulates from Sarigan, which has improved native habitat that supports
two species in this final rule, the humped tree snail and Slevin's
skink, by decreasing the impacts of trampling and browsing on native
plants. Sarigan may serve as a location for recovery of Slevin's skink
and the humped tree snail.
Since 1993, the U.S. Department of Agriculture, Wildlife Services'
Brown Treesnake Program in Guam has been working to prevent the
inadvertent spread of the snake to other locations, and to reduce
negative impacts by the brown treesnake on economic and ecological
resources. Experimentation with toxicant drops to control the brown
treesnake is ongoing. The U.S. Department of Agriculture, Wildlife
Services, is the lead agency for this work, in cooperation with the
National Wildlife Research Center, U.S. Geological Survey, the U.S.
Fish and Wildlife Service, and the U.S. Department of Defense. Results
of the toxicant drops are currently under review (Phillips 2014, in
litt.). Additionally, in fiscal year (FY) 2014, the Navy funded $1.8
million in projects to meet objectives for control, suppression, and
eradication of brown treesnakes to benefit native species, including
the 23 species addressed in this rule, and their habitat. Funding has
been programmed to continue this effort through 2021. Also in FY2014
the Navy funded $3.3 million for control and containment to prevent the
spread and establishment of brown treesnakes to new areas, including
the CNMI where 17 of the 23 species addressed in this final rule occur.
Area 50, a 59-ac (24-ha) exclosure on Andersen AFB on Guam
containing a relictual patch of limestone forest, was created to
exclude ungulates and the brown treesnake (Hess and Pratt 2006, p. 2).
This enclosure was maintained for ecosystem and species experimental
research. Several individuals of the tree Tabernaemontana rotensis
occur within the enclosure, and would benefit from protection from
predators and habitat disturbance (Hess and Pratt 2006, p. 7). However,
researchers found the enclosure in a state of neglect, and invaded by
nonnative plant species and pigs, with only 20 ac (8 ha) of undisturbed
primary forest remaining by 2006 (Hess and Pratt 2006, p. 24). We are
unaware of any efforts to continue maintenance of this enclosure since
that time. In 2014, the Air Force completed the construction of a 306-
ac (124-ha) exclosure on Andersen AFB (U.S. Department of Navy (DON)
2014, in litt.); however, through the Joint Guam Program Office (JGPO),
the U.S. Navy has proposed a live-fire training range within a large
portion of the fenced area. Additionally, this exclosure is a
mitigation measure for a previous DOD action (Intelligence,
Surveillance, Reconnaissance Strike Project). There are proposed
mitigation measures associated with the new live-fire training range,
but because they are only proposed at this time they are not included
in this final rule. Also in 2014, the Navy also funded a project to
examine the distribution and abundance of Tabernaemontana rotensis on
Joint Regional Marianas (JRM) lands (DON 2014, in litt.).
Rota's Department of Fish and Wildlife constructed exclosures for
two occurrences of Tabernaemontana rotensis in the Sabana Conservation
Area, but only one exclosure remains, as the other burned in a fire
(Hess and Pratt 2006, p. 33; 65 FR 35029, June 1, 2000).
The Micronesian Challenge is a commitment by the Federated States
of Micronesia, the Republic of Palau, the Republic of the Marshall
Islands, Guam, and the CNMI to preserve at least 30 percent of near-
shore marine resources
[[Page 59461]]
and 20 percent of the terrestrial resources across Micronesia by 2020
(Micronesian Challenge 2011, in litt.). The CNMI Government is already
attempting to meet this goal by planning to designate conservation
lands within native forest (CNMI-SWARS 2010, p. 30). The Micronesian
Challenge organization has partnered with many national and
international environmental organizations (e.g., The Nature
Conservancy, Micronesian Conservation Trust, and the New York Botanical
Gardens), and focuses on conservation outreach to native Micronesians
and visitors (Micronesian Challenge 2011, in litt.; http://themicronesiachallenge.blogspot.com/p/links.html).
Summary of Habitat Destruction and Modification
The threats to the habitats of each of the 23 Mariana Islands
species are occurring throughout the entire range of each of the
species, except where noted above, with consequent deleterious effects
on individuals and populations of these species. These threats include
land conversion by agriculture and urbanization, habitat destruction
and modification by nonnative animals and plants, fire, the potential
alteration of environmental conditions resulting from climate change,
and compounded impacts due to the interaction of these threats. While
the conservation measures described above address some threats to the
23 species, due to the pervasive and expansive nature of the threats
resulting in habitat degradation, these measures are insufficient to
eliminate these threats to any of the 23 species addressed in this
final rule.
Development and urbanization represents a serious and ongoing
threat to 21 of the 23 species because they cause permanent loss and
degradation of habitat.
The effects from ungulates are ongoing because ungulates currently
occur in all 4 ecosystems that support the 23 species in this final
rule. The threat of habitat destruction and modification posed by
introduced ungulates is serious, because they cause: (1) Trampling and
grazing that directly impacts plants, including 10 of the 14 plant
species addressed in this rule, and the 2 host plants used by the
Mariana eight-spot butterfly for shelter, foraging, and reproduction;
(2) increased soil disturbance, leading to mechanical damage to
individuals of 10 of the 14 plant species, and also the host plants for
the Mariana eight-spot butterfly; (3) creation of open, disturbed areas
conducive to weedy plant invasion and establishment of alien plants
from dispersed fruits and seeds, which results over time in the
conversion of a community dominated by native vegetation to one
dominated by nonnative vegetation; and (4) increased erosion, leading
to destabilization of soils that support native plant communities,
elimination of herbaceous understory vegetation, and creation of
disturbed areas into which nonnative plants invade. The brown treesnake
and rats both negatively impact the four ecosystems by eating native
animals that native plants rely on to disperse seeds, limiting the
regenerative capacity of the native forest. These threats are expected
to continue or increase without ungulate control or eradication.
Nonnative plants represent a serious and ongoing threat to 20 of
the 23 species addressed in this final rule (all 14 plant species, the
Mariana eight-spot butterfly, the Rota blue damselfly, and all 4 tree
snails) (see Table 3) through habitat destruction and modification,
because they: (1) Adversely impact microhabitat by modifying the
availability of light; (2) alter soil-water regimes; (3) modify
nutrient cycling processes; (4) alter fire characteristics of native
plant habitat, leading to incursions of fire-tolerant nonnative plant
species into native habitat; (5) outcompete, and possibly directly
inhibit the growth of, native plant species; and (6) create
opportunities for subsequent establishment of nonnative vertebrates and
invertebrates. Each of these threats can convert native-dominated plant
communities to nonnative plant communities (Cuddihy and Stone 1990, p.
74; Vitousek 1992, pp. 33-36). This conversion has negative impacts on
all 14 plant species addressed here, as well as the native plant
species upon which the Mariana eight-spot butterfly and the Rota blue
damselfly depend for essential life-history needs. For example,
nonnative plants that outcompete native plants can destabilize
streambanks, exacerbating the potential for landslides and rockfalls,
in turn dislodging Rota blue damselfly eggs and naiads from streams,
and also displace or destroy vegetation used for perching by adults,
leaving them more susceptible to predation.
The threat from fire to 11 of the 23 species in this final rule
that depend on the savanna ecosystem and adjacent forest ecosystems (9
plant species: Bulbophyllum guamense, Cycas micronesica, Dendrobium
guamense, Hedyotis megalantha, Maesa walkeri, Nervilia jacksoniae,
Phyllanthus saffordii, Tabernaemontana rotensis, and Tuberolabium
guamense; and 2 animal species: The Guam tree snail and the humped tree
snail) (see Table 3, above) is serious and ongoing because fire damages
and destroys native vegetation, including dormant seeds, seedlings, and
juvenile and adult plants. After a fire, nonnative, invasive plants,
particularly fire-tolerant grasses, outcompete native plants and
inhibit their regeneration (D'Antonio and Vitousek 1992, pp. 70, 73-74;
Tunison et al. 2002, p. 122; Berger et al. 2005, p. 38; CNMI-SWARS
2010, pp. 7, 20; JGPO-NavFac, Pacific 2010b, p. 4-33). Successive fires
that burn farther and farther into native habitat destroy native plants
and animals, and remove habitat for native species by altering
microclimatic conditions and creating conditions favorable to alien
plants. The threat from fire is unpredictable but increasing in
frequency in the savanna ecosystem that has been invaded by nonnative
fire-prone grasses, and that is subject to abnormally dry to severe
drought conditions.
Natural disasters, such as typhoons, are a threat to native
terrestrial habitats on the Mariana Islands in all 4 ecosystems
addressed here, and to all 14 plant species identified in this final
rule, because they result in direct impacts to ecosystems and
individual plants by opening the forest canopy, modifying available
light, and creating disturbed areas that are conducive to invasion by
nonnative pest plants (Asner and Goldstein 1997, p. 148; Harrington et
al. 1997, pp. 346-347; Berger et al. 2005, pp. 36, 45, 71, 100, 144;
CNMI-SWARS 2010, p. 10; JGPO-NavFac, Pacific 2010b, pp. 1-8). In
addition, typhoons are a threat to the nine animal species in this rule
because strong winds and intense rainfall can kill individual animals,
and can cause direct damage to streams (Polhemus 1993, pp. 86-87). High
winds and torrential rains associated with typhoons can also destroy
the host plants for the two butterfly species, and can dislodge
individual butterflies and their larvae from their host plants and
deposit them on the ground where they may be crushed by falling debris
or eaten by nonnative wasps and ants. In addition, the high winds can
dislodge bats from their caves and cause individual harm or death.
Typhoons pose an ongoing threat because they are unpredictable and can
occur at any time. Although typhoons are a natural occurrence in the
Pacific, their impact can be particularly devastating to the 23 species
because, as a result of other threats, they now persist in low numbers
or occur in restricted ranges and are, therefore, less resilient to
such disturbances, rendering them highly vulnerable. In such cases, a
particularly
[[Page 59462]]
destructive super typhoon could potentially drive localized endemic
species to extinction in a single event.
B. Overutilization for Commercial, Recreational, Scientific, or
Educational Purposes
Plants
We are not aware of any threats to the 14 plant species that would
be attributed to overutilization for commercial, recreational,
scientific, or educational purposes.
Animals
We are not aware of any threats to five of the nine animal species
(the two Mariana butterflies, Pacific sheath-tailed bat, Slevin's
skink, or Rota blue damselfly) addressed in this final rule that would
be attributed to overutilization for commercial, recreational,
scientific, or educational purposes. We do have evidence indicating
that collection is a threat to the four tree snail species addressed in
this final rule, as discussed below.
Tree Snails--Tree snails can be found around the world in tropical
and subtropical regions and have been valued as collectibles for
centuries. Evidence of tree snail trading among prehistoric Polynesians
was discovered by analysis of the multi-archipelagic distribution of
the Tahitian endemic Partula hyalina and related taxa (Lee et al. 2007,
pp. 2,907, 2,910). In their study, Lee et al. (2007, pp. 2,908-2,910)
found evidence that P. hyalina had been traded as far away as Mangaia
in the Southern Cook Islands, a distance of more than 500 mi (805 km).
The endemic Hawaiian tree snails within the family Achatinellidae were
extensively collected for scientific as well as recreational purposes
by Europeans in the 18th to early 20th centuries (Hadfield 1986, p.
322). Historically, tree snails were abundant in the Pacific Islands.
During the 1800s collectors observed 500 to 2,000 snails per tree, and
sometimes collected more than 4,000 snails in several hours (Hadfield
1986, p. 322). Likewise, in the Mariana Islands, Crampton (an early
naturalist in the islands) alone took 2,666 adult humped tree snails
from 8 sites on Saipan in just 6 days in 1925 (Crampton 1925, p. 100).
Repeated collections of hundreds to thousands of individuals at a time
by early collectors may have contributed to decreased population sizes
and reduction of reproduction potential due to the removal of potential
breeding adults (Hadfield 1986, p. 327). The collection of tree snails
persists to this day, and the market for rare tree snails serves as an
incentive to collect them. A search of the Internet (e.g., eBay and
Etsy) reveals Web sites that offer snail shells from more than 100 land
and sea snail species (along with corals and sand) from around the
world, including rare and listed Achatinella and Partulina. These sites
encourage collectors by making statements such as ``These assorted land
snail shells from the tropical regions of the world are great for
crafters and decorations for tanks'' and refer to shells with colorful
names such as ``rainbow shells from Haiti'' (http://www.shells-of-aquarius.com/snail-shells.html; https://www.etsy.com/uk/search?q=tree+snail). Concerned citizens alert law enforcement of
Internet sales and notify the public about illegal sales through
personal web blogs (http://bioacoustics.blogspot.com/2012/04/endangered-species-on-ebay.html). Over the past 100 years, Mariana
species of partulid tree snail shells have been made into jewelry and
purses and sold to tourists (Kerr 2013, p. 3). As recent as 2012,
jewelry made with partulid shells has been observed in stores in the
Mariana Islands (USFWS 2012, in litt.). Based on the history of
collection of Pacific island tree snails, the market for Mariana tree
snail shells, and the vulnerability of the small populations of the
humped tree snail, Langford's tree snail, the Guam tree snail, and the
fragile tree snail, we consider collection a threat to the four endemic
Mariana tree snail species listed as endangered species in this rule.
Summary of Overutilization for Commercial, Recreational, Scientific, or
Educational Purposes
We have no evidence to suggest that overutilization for commercial,
recreational, scientific, or educational purposes poses a threat to any
of the 14 plant species, 2 butterflies, Pacific sheath-tailed bat,
Slevin's skink, or Rota blue damselfly listed as endangered or
threatened species in this final rule. We consider the four species of
tree snails vulnerable to the impacts of overutilization due to
collection for trade or market. Based on the history of collection of
Pacific tree snails, the current market for Marianas tree snail shells
and tree snail shells world-wide, and the inherent vulnerability of the
small populations of the Guam tree snail, the humped tree snail,
Langford's tree snail, and the fragile tree snail to the removal of
breeding adults, we consider collection to pose a serious and ongoing
threat to these species.
Factor C. Disease and Predation
Disease
We are not aware of any threats to the 23 species addressed in this
final rule that would be attributable to disease.
Predation and Herbivory
There are multiple animal species, ranging from mammals and rodents
to reptiles and insects, reported to impact 17 of the 23 species listed
as endangered or threatened species in this final rule by means of
predation or herbivory (Table 3). Those species that have the most
direct negative impact on the 23 species include: Feral pigs,
Philippine deer, rats, the brown treesnake, monitor lizards, Cuban
slugs (Veronicella cubensis), the manokwari flatworm, the cycad
aulacaspis scale, ants (Tapinoma minutum, Technomyrmex albipes,
Monomorium floricola, and Solenopsis geminata), and parasitoid wasps
(Telenomus sp. and Ooencyrtus sp.). Data show these nonnative animals
have caused a decline of 17 of the 23 species (Intoh 1986 in Conry
1988, p. 26; Fritts and Rodda 1998, pp. 130-133). Although feral goats,
cattle, and water buffalo occur on one or more of the Mariana Islands
and are recognized to negatively impact the ecosystems in which they
occur (see ``Factor A. The Present or Threatened Destruction,
Modification, or Curtailment of Its Habitat or Range,'' above), we have
no direct evidence that goats, cattle, or water buffalo browse
specifically on any of the 14 plant species addressed in this final
rule.
Ungulates
Pigs--Feral pigs are widely recognized to negatively alter
ecosystems (see ``Habitat Destruction and Modification by Introduced
Ungulates,'' above). In addition, feral pigs have been observed to eat
the leaves, fruits, seeds, seedlings, or bark from 4 of the 14 plant
species listed as endangered or threatened species in this final rule
(Cycas micronesica, Heritiera longipetiolata, Psychotria malaspinae,
and Solanum guamense) in the forest ecosystem (Perlman and Wood 1994,
pp. 135-136; Harrington et al. 2012, in litt.; Rogers 2012, in litt.;
Marler 2013, pers. comm.). Similarly, on other Pacific islands (e.g.,
the Hawaiian Islands), pigs are known to eat and fell plants and remove
the bark from a variety of native plant species, including Clermontia
spp., Cyanea spp., Cyrtandra spp., Hedyotis spp., Psychotria spp., and
Scaevola spp. (Diong 1982, p. 144). In addition, evidence of pigs
feeding on Cycas micronesica has been observed, hypothesized as a means
to obtain grubs
[[Page 59463]]
(Harrington et al. 2012, in litt.). Pigs also eat standing living stems
of plants, thought to be for the same intent (Marler 2013, pers.
comm.). Feral pigs have been documented to eat the host plants that
support the Mariana eight-spot butterfly (Procris pendunculata and
Elatostema calcareum).
In addition to deer imposing negative impacts on habitat at an
ecosystem scale in the Mariana Islands on which they occur (primarily
Guam and Rota), deer are known to consume leaves, seeds, fruits, and
bark of 5 of the 14 plant species (Cycas micronesica, Eugenia bryanii
(deer are known to consume all Mariana Islands Eugenia spp.), Heritiera
longipetiolata, Psychotria malaspinae, and Solanum guamense), and the 2
host plants for the Mariana eight-spot butterfly (Wiles et al. 1999,
pp. 198-200, 203; Rubinoff and Haines 2012, in litt.).
Other Nonnative Vertebrates
Rats
Rat Predation on Tree Snails--Rats (Rattus spp.) have been
suggested as responsible for the greatest number of animal extinctions
on islands throughout the world, including extinctions of various snail
species (Towns et al. 2006, p. 88). Rats are known to prey upon Pacific
island endemic arboreal snails (Hadfield et al. 1993, p. 621). In the
Waianae mountains of Oahu, Meyer and Shiels (2009, p. 344) found shells
of the endemic Oahu tree snail (Achatinella mustelina) with
characteristic rat damage (e.g., damage to the shell opening and cone
tip), but noted that, since a high proportion of crushed shells could
not reliably be collected in the field, the impact of rat predation on
snail populations may be underestimated. Rat predation on tree snails
has also been observed on the Hawaiian Islands of Lanai (Hobdy 1993, p.
208; Hadfield 2005, in litt, p. 4), Molokai (Hadfield and Saufler 2009,
p. 1,595), and Maui (Hadfield 2006, in litt.). Rat populations on Guam
may be limited by predation by the brown treesnake, thereby limiting
rat predation on native tree snails. Because rats occur in larger
numbers on the Mariana Islands to the north of Guam, rat predation is
considered a threat to the three tree snail species addressed in this
final rule that occur on the other Mariana Islands (the humped tree
snail on Rota, Aguiguan, Saipan, Sarigan, Alamagan, and Pagan; the
fragile tree snail on Rota; and Langford's tree snail on Aguiguan).
Rat Predation on Bats--Rats may prey on the Pacific sheath-tailed
bat, listed as an endangered species in this final rule. Rats are
omnivores and are opportunistic feeders. Rats have a widely varied diet
consisting of nuts, seeds, grains, vegetables, fruits, insects, worms,
snails, eggs, frogs, fish, reptiles, birds, and mammals (Fellers 2000,
p. 525; GISD 2014, in litt.). Rats occur on Aguiguan, the only island
on which the Pacific sheath-tailed bat is known to roost (Berger et al.
2005, p. 144). Rats are predators on young bats at roosts (that are
nonvolant, i.e., have not yet developed the ability to fly) (Wiles et
al. 2011, p. 306). The black rat was determined to be the primary
factor in reproductive failure for a maternal colony of Townsend's big-
eared bat (Corynorhinus townsendii) in California (Fellers 2000, pp.
524-525). Many of the roosting sites used by the Pacific sheath-tailed
bat on Aguiguan appear to be impassable to rats; however, this may be
due to rats limiting the selection of roosting sites because of their
foraging and surveillance for prey in caves (Wiles and Worthington
2002, p. 18; Berger et al. 2005, p. 144). Because rats occur on all of
the Mariana Islands, the Service considers rats a threat to the Pacific
sheath-tailed bat.
Rat Predation on Skinks--Rats are known to prey on a variety of
skink species around the globe (Crook 1973 in Towns et al. 2001, p. 3;
Whitaker 1973 in Towns et al. 2001, p. 3; McCallum 1986 in Towns et al.
2001, p. 3; Towns et al. 2001, pp. 3-4, 6-8; Towns et al. 2006, pp.
875-877, 883). A New Zealand study showed the cause of the decline of
rare reptiles on island reserves became evident through associations
with the spread of Pacific rats (Rattus exulans) to these island
reserves (Crook, 1973; Whitaker, 1973, 1978; and McCallum, 1986 in
Towns et al. 2001, p. 3). Other restoration projects in New Zealand
have demonstrated the native reptile populations undergo a resurgence
following aggressive conservation activities to control predatory
mammals, especially rodents (Towns et al. 2001, p. 3). The reptile
species showing the most rapid response to removal of rats was the
shore skink (Oligosoma smithi), with an increase of the capture
frequency of shore skinks by up to 3,600 percent over 9 years (Towns
1994, unpub. in Towns et al. 2001, p. 10). Rats occur on all of the
Mariana Islands and are a threat to the Slevin's skink on the islands
on which it currently occurs (Cocos Island, Alamagan, and Sarigan), and
are a threat on islands where the skink was observed in the 1980s and
1990s (Guguan, Pagan, and Asuncion) but for which their current status
is unknown. Once thought to be extirpated from Cocos Island (just
offshore of Guam), Slevin's skink was observed on Cocos Island for the
first time in more than 20 years following the eradication of rats and
monitor lizards (Fisher 2012 pers. comm., in IUCN 2014, in litt.),
indicating that predation by these nonnative species has a significant
negative effect on skink populations.
Brown Treesnake
The brown treesnake (see ``Habitat Destruction and Modification by
Introduced Small Vertebrates,'' above) preys upon a wide variety of
animals, and although it is only known to occur on Guam at this time,
it is an enormous concern that the brown treesnake will be introduced
to other Mariana Islands (The Brown Treesnake Control Committee 1996,
pp. 1, 5; USFWS-Brown Treesnake Strategic Plan 2015, pp. 1-85). This
nocturnal arboreal snake occupies all ecosystems on Guam, and consumes
small mammals and lizards, usually in their neonatal state (Rodda and
Savidge 2007, pp. 307, 314). The brown treesnake is attributed with the
extirpation, or contribution thereof, of 13 of Guam's 22 native bird
species. Roosting and nesting birds, eggs, and nestlings are all
vulnerable. If the brown treesnake establishes on any other of the
Mariana Islands it will impose a wide range of negative impacts, both
environmental and economic (Campbell 2014, pers. comm.).
Brown Treesnake Predation on Bats--The brown treesnake has the
potential to prey on fruit bats and the Pacific sheath-tailed bat, as
brown treesnake are known to climb in caves and prey on Mariana
swiftlets. Predation by treesnakes possibly caused losses of sheath-
tailed bats in southern Guam in the 1950s and 1960s, but invaded
northern Guam too late to have played a role in the bat's extirpation
there (Wiles et al. 2011, p. 306). If the brown treesnake should be
introduced to Aguiguan, the only island in the Mariana archipelago that
currently supports a population of the Pacific sheath-tailed bat, it
would negatively affect this population, either by predation or by
limiting available cave sites (Rodda and Savidge 2007, p. 307).
Additionally, if the BTS is introduced to islands in the Mariana
archipelago that historically supported the Pacific sheath-tailed bat
(i.e., Guam, Rota, Saipan, Tinian, Anatahan, and Maug), recovery for
this species will be difficult, and the Service considers the brown
treesnake a potential threat to the Pacific sheath-tailed bat on these
islands.
Brown Treesnake Predation on Skinks--The brown treesnake is known
[[Page 59464]]
to prey on a wide variety of small vertebrates on Guam, including
skinks. Juvenile brown treesnake are known to feed exclusively on
lizards (including skinks) (Savidge 1988, in Rodda and Savidge 2007,
pp. 314-315). In one study, 250 food items were taken from the
digestive systems of brown treesnake, and of these, 194 were lizards or
lizard eggs (Savidge 1988 cited in Rodda and Fritts 1992, p. 166). If
the brown treesnake is introduced to any of the islands that currently
(Cocos Island, Alamagan, and Sarigan) or historically (Guam, Rota,
Tinian, Aguiguan, Guguan, and Pagan) support the Slevin's skink, it
will negatively impact by decreasing populations and the numbers of
individuals, and when combined with habitat loss, and other threats,
could lead to their extirpation. Additionally, if the brown treesnake
is introduced to islands where the Slevin's skink occurred historically
(Guam, Rota, Tinian, Aguiguan, Guguan, and Pagan), recovery for this
species will be difficult, and the Service considers the brown
treesnake a potential threat to the Slevin's skink on these islands.
Monitor Lizard
Monitor Lizard Predation on Bats--The monitor lizard (hilitai,
Varanus indicus), a carnivorous, terrestrial, arboreal lizard that can
grow up to 3 ft (1 m) in length, is present on every island in the
Mariana Islands except for Farallon de Medinilla, Guguan, Asuncion,
Maug, and Uracas (Vogt and Williams 2004, pp. 76-77). It is unknown
when the monitor lizard was introduced to Guam and the Northern Mariana
Islands; however, it is known that the presence of this species in the
islands predates European contact (Vogt and Williams, p. 77). Monitor
lizards typically hunt over large areas and feed frequently on a wide
variety of prey including, but not limited to, crabs, snails, snakes,
lizards, skinks, fish, rats, squirrels, rabbits, sea turtle eggs, and
birds (Losos and Greene 1988, pp. 379, 393; Bennet 1995 in ISSG-GISD
2007, in litt.). In the Mariana Islands, monitor lizards prey on both
invertebrates and vertebrates, including large animals like chickens
and the endangered Micronesian megapode (Martin et al. 2008 in IUCN
2007, in litt.). Considering their varied diet, which includes small
vertebrates, and given the opportunity, predation by monitor lizards is
a threat to the Pacific sheath-tailed bat listed as an endangered
species in this rule, in the forest and cave ecosystems (USDA-NRCS
2009, p. 8).
Monitor Lizard Predation on Skinks--Monitor lizards are known to
prey on all life stages of lizards (eggs, juveniles, and adults), and
also other monitor lizards; therefore, we expect that monitor lizards
negatively impact the Slevin's skink as well (Rodda and Fritts 1992,
pp. 166-174; Vogt 2010, in litt.). The specific reasons for the decline
of Slevin's skink (currently known from only 3 of the 10 islands where
occurrences have been noted) are not known. Rodda et al. (1991) suggest
that the combination of introduced species such as rats and shrews and
other reptiles negatively impact native reptile populations, including
Slevin's skink, by aggressively competing for habitat and food
resources, and through predation (see ``Rat Predation on Skinks,''
above) (Rodda et al. 1991 in Berger et al. 2005, pp. 174-175). The
monitor lizard is known to have a varied diet (coconut crabs, snails,
snakes, lizards, skinks, fish, rats, sea turtle eggs, and birds)
(Berger et al. 2005, pp. 69-70, 90, 347-348; Losos and Greene 1988, pp.
379, 393; Bennet 1995 in ISSG-GISD 2007, in litt.; Cota 2008, pp. 18-
27); therefore, predation of Slevin's skink by monitor lizards is a
threat to the Slevin's skink throughout its range in the Mariana
Islands.
Nonnative Fish Predation on Damselflies
A survey of the Okgok River (or Okgok Stream, also known as Babao),
conducted in 1996, showed that only four fish species (all native
species) were present: The eel Anguila marmorata, the mountain gobies
Stiphodon elegans and Sicyopus leprurus, and the flagtail or mountain
bass, Kuhlia rupestris. Other freshwater species observed included a
prawn, shrimps, and gastropods (Camacho et al. 1997, pp. 8-9).
Densities of these native fish were low, especially in areas above the
waterfall. Gobies can maneuver in areas of rapidly flowing water by
using ventral fins that are modified to form a sucking disk (Ego 1956,
in litt.). Freshwater gobies in Hawaii are primarily browsers and
bottom feeders, often eating algae off rocks and boulders, with midges
and worms being their primary food items (Ego 1956, in litt.; Kido et
al. 1993, p. 47). The flagtails were abundant only in the lower reach
of the stream. We can only speculate that the Rota blue damselfly may
have adapted its behavior to avoid the benthic feeding habits of native
fish species.
Nonnative fish (Gambusia spp.) were introduced to Guam streams for
mosquito control. Other nonnative fish from the aquarium trade (e.g.,
guppies, swordtails, mollies, betta, oscars, and koi) have been
released and documented in Guam streams. Currently, none of these fish
are known from the Okgok River (Okgok Stream, Babao) on Rota, but
biologists believe that Gambusia and guppies would be the most likely
species to be introduced (Tibbatts 2014, in litt.). The release of
aquarium fish into streams and rivers of Guam is well documented, but
currently, no nonnative fish have been found in the Rota stream
(Tibbatts 2014, in litt.). Therefore, release of nonnative fish is only
a potential threat at this time, as they could impact the Rota blue
damselfly by eating the naiad life stage, interrupting its life-cycle,
and leading to its extirpation.
Nonnative Invertebrates
Slug Herbivory on Native Plants--The nonnative Cuban slug
(Veronicella cubensis) is considered one of the greatest threats to
native plant species on Pacific Islands (Robinson and Hollingsworth
2006, p. 2). The Cuban slug is a recent introduction to the Micronesian
islands. These terrestrial mollusks are generalist feeders, and can
attack a wide variety of plants, and switch food preferences if
potential food plants change (Robinson and Hollingsworth 2006, p. 2).
Slugs feed on the two host plants (Elatostema calcareum and Procris
pendunculata) that support the Mariana eight-spot butterfly, being
listed as endangered in this final rule. The Cuban slug has been known
on Rota since 1996, occurs in large numbers, and is currently a pest to
agricultural and ornamental crops on the island (Badilles et al. 2010,
pp. 2, 4, 8). Some agricultural losses are reported to be as high as 70
percent of the crop (Badilles et al. 2010, p. 7). In addition, these
slugs are known to attack orchids, which place all four species of
orchids listed as threatened species in this final rule (Bulbophyllum
guamense, Dendrobium guamense, Nervilia jacksoniae, and Tuberolabium
guamense) at risk from slug predation on the islands of Guam and Rota
(Badilles et al. 2010, p. 7; Cook 2012, in litt.).
Flatworm Predation on Tree Snails--The extinction of native land
snails on several Pacific Islands has been attributed to the
terrestrial manokwari flatworm (Platydemus manokwari; also known as the
New Guinea flatworm), native to western New Guinea (Cowie 2001, p. 120;
Sugiura and Okochi 2006, p. 700; Sugiura 2010, p. 1,499; Global
Invasive Species Database (GISD)-Invasive Species Specialist Group
(ISSG)-International Union for Conservation of Nature (IUCN)1,499;
GISD-ISSG-IUCN Species Survival Commission 2010, in litt.; Cowie 2014,
in litt.; Fiedler 2014, in litt.; Hopper
[[Page 59465]]
2014, in litt.; Commonwealth Agricultural Bureau International (CABI-
Invasive Species Compendium 2015, in litt.). It is believed to occur on
most of the southern Mariana Islands, and was first observed on Guam in
1978 (Hopper and Smith 1992, pp. 78, 82-83; Berger et al. 2005, p.
158). In many areas, the flatworm was initially introduced
intentionally for the purpose of controlling the nonnative giant
African snail (Achatinella fulica); it was found to be effective in
reducing the abundance of the giant African snail by as much as 95
percent (Hopper and Smith 1992, p. 82). This flatworm has diminished
numbers of two nonnative predatory snails, the rosy wolf snail
(Euglandina rosea) and Gonaxis spp., both of which are widely
recognized as significant contributors to the overall decline in tree
snails throughout the Pacific (Hadfield 1986, pp. 325-330; Cowie 1992,
p. 171; Hopper and Smith 1992, p. 78; Kerr 2013, pp. 5-6). Some snail
experts propose that, due to the presence of the manokwari flatworm,
these two nonnative snails are no longer a threat to the Mariana
Islands tree snails (Kerr 2013, p. 5). However, other snail experts are
not so quick to discount the possible future impacts of these two
predators (Cowie 2014, in litt.). The manokwari flatworm is highly
invasive and preys on live snails of any species (Sugiura et al. 2006,
p. 700, and references therein), and thus poses a significant threat to
all endemic snails of the Mariana Islands.
The manokwari flatworm is capable of spreading easily to new
geographic areas through inadvertent introductions and despite
agricultural controls and regulations. First discovered in New Guinea
in 1962, it is now found in Australia, Japan, Indonesia, the Caribbean
(Puerto Rico), and numerous Pacific Islands (e.g., Fiji, Tahiti,
Singapore, Samoa, Philippines), including the Mariana Islands. It is
known to occur on Guam, Rota, Tinian, Saipan, and Aguiguan (Hopper and
Smith 1992, p. 77; ISSG-GISD 2015, in litt.). Its propensity to spread
through inadvertent introduction is illustrated by recent discoveries
of the manokwari flatworm in both France (Justine et al. 2015, p. 2)
and the mainland United States in Florida (Justine et al. 2015, p. 1).
The manokwari flatworm exhibits remarkable fecundity. In laboratory
studies, individuals reached sexual maturity just 3 weeks after
hatching, and the time period from copulation to cocoon-laying ranged
from 2 to 40 days, at which time a single cocoon is produced (Kaneda et
al. 1990, p. 526). Cocoon-laying usually occurred at 7- to 10-day
intervals, with some adults over 200 days old still capable of laying
(Kaneda et al. 1990, p. 526). Each cocoon produced 3 to 9 juveniles,
with a mean number of 5 (Kaneda et al. 1990, p. 526). Adequately fed
adults lived up to 2 years, and starved adults lived up to 1 year
(Kaneda et al. 1990, p. 526). Additionally, manokwari flatworms are
very fragile and may fragment into pieces, with each piece having the
potential to regenerate into a complete flatworm (Kaneda et al. 1990,
p. 526).
In contrast, partulid snails are generally slow-growing, long-
lived, and slow-reproducing land snails (Cowie 1992, p. 194). Partulids
can live up to 5 years and reach maturity at approximately 1 year, or a
little less, in age (Murray and Clark 1966 pp. 1,264-1,277; Cowie 1992,
p. 174). Partulids produce their first offspring between 16 and 24
months of age, and give birth to a single juvenile on average about
every 20 days thereafter (Murray and Clark 1966 pp. 1,264-1,277; Cowie
1992, p. 174). These differences in life-history characteristics place
the endemic partulid snails at a disadvantage, as the predatory
manokwari flatworm can quickly reproduce in large numbers and overwhelm
the small numbers of remaining tree snails.
The manokwari flatworm can be found on the ground as well as meters
up in native trees and is more active during rain events (Hopper 2014,
in litt.). This flatworm is known to feed on juvenile and adult
partulid snails (Hopper and Smith 1992, p. 82; Iwai et al. 2010, pp.
997-1,002; Sugiura 2010, pp. 1,499-1,507; Hopper 2014, in litt.).
Studies of captive partulids at the UOG Marine Laboratory showed that a
single manokwari flatworm consume four to five adult snails over a
single week, averaging one killed and consumed every other day (Hopper
2014, in litt.). The manokwari flatworm is able to track snails based
on chemical cues in their mucus trails, and can discriminate between,
and show a preference for, particular snail species (Iwai et al. 2010,
p. 1,000). Controlled experiments in the Ogasawara Islands demonstrated
flatworm predation on 50 percent of the snails available in the test
area within 3 days, and 90 percent snail mortality due to predation
within 11 days (Sugiura et al. 2006, p. 702). The manokwari flatworm is
considered a highly effective predator on Mariana Partulidae, of all
age classes, and likely all other native and nonnative terrestrial
snails (Hopper 2014, in litt.). Hopper (2014, in litt.) asserts that
the manokwari flatworm is the most important threat to tree snails
since it occurs in native forests as well as nonnative and disturbed
forest. Fiedler (2014, in litt.) describes tree snails on Guam as
occurring in proximity to sources of fresh water (river, ponds, or near
surface ground water) and high humidity, which are also conditions
ideal for the predatory manokwari flatworm, and notes that the flatworm
has been observed at nearly every location where partulid snails occur
on Guam.
There are no known natural enemies of the manokwari flatworm, and
no biological controls that would not also kill the four tree snails.
One exception is that hot water has been suggested as a physical
control, after laboratory studies showed that the temperature of water
required to kill flatworms (109 [deg]Fahrenheit (F) (43 [deg]Celsius
(C))) is lower than the temperature to kill snails (122 [deg]F (50
[deg]C)) (Sugiura 2008, p. 207); however, we are unaware of this method
being implemented in the field. This method is employed during the
quarantine of ornamental plants in some areas (Sugiura 2008, p. 207).
It is unknown if the temperature that kills flatworms may harm the
reproductive or other necessary biological functions of snails, even
though it does not kill them.
In summary, the manokwari flatworm's arboreal habits, voracious
appetite, and high fecundity make this predator a very harmful invasive
species (GISD-ISSG 2010, in litt.). The IUCN Invasive Species
Specialist Group has named the manokwari flatworm to its list of 100 of
the World's Worst Invasive Alien Species (ISSG 2004, pp. 6-7). As
referenced above, the manokwari flatworm is already credited with the
extinction of several island endemic snail species. Due to its
widespread occurrence on the southern Mariana Islands, and the risk of
unintentional introduction on the northern Mariana Islands, predation
by the manokwari flatworm is considered a threat to all four tree snail
species (the Guam tree snail, the humped tree snail, Langford's tree
snail, and the fragile tree snail) listed as endangered species in this
final rule. These four snails are also experiencing habitat loss due to
development, habitat degradation by nonnative plants and animals,
predation by rats, and threats associated with low heterozygosity. As
populations of the tree snails have been reduced in both number and
distribution, they are also vulnerable to negative impacts resulting
from future climate change and typhoons.
Scale Herbivory on Cycas--Cycas micronesica is currently declining
on two (Guam and Rota) of the five Micronesian islands on which it
occurs
[[Page 59466]]
due to the presence of a phytophagous (plant-eating) insect, the cycad
aulacaspis scale (Aulacaspis yasumatsui) (Marler and Lawrence 2012, pp.
238-240; Marler 2012, pers. comm.). The cycad aulacaspis scale, first
described in Thailand (Takagi 1977 in Marler and Lawrence 2012, p.
233), was unintentionally introduced into the United States (Florida) a
little more than 20 years ago (Howard et al. 1999 in Marler and
Lawrence 2012, p. 233), subsequently spreading to other regions. It was
introduced to Guam in 2003, possibly via importation of the landscape
cycad, Cycas revoluta (Marler and Lawrence 2012, p. 233). By 2005, the
cycad aulacaspis scale had spread throughout the forests of Guam.
Although this scale has infested C. micronesica populations on Guam,
Rota, and the larger islands of Palau, most of the data has been
collected on Guam, where more than 50 percent of the total known Cycas
individuals occur (Marler 2012, pers. comm.). In 2002, prior to the
scale infestation, C. micronesica was the most abundant tree species on
Guam (Donnegan et al. 2002, p. 16). At an international meeting of the
Cycad Specialist Group in Mexico in 2005, the cycad aulacaspis scale
was identified as a critical issue for cycad conservation worldwide and
was given priority status (IUCN/Species Survival Commission Cycad
Specialist Group 2014, in litt.).
The cycad aulacaspis scale attacks every part of the leaf, which
subsequently turns white. The leaf then collapses, and with progressive
infestation, death of the entire plant can occur in less than 1 year
(Marler and Muniappan 2006, pp. 3-4). Field studies conducted on the
Guam National Wildlife Refuge on Guam by Marler and Lawrence (2012, p.
233) between 2004 and 2011 found that 6 years after the cycad
aulacaspis scale was found on the refuge, mortality of C. micronesica
there had reached 92 percent. The scale first killed all seedlings at
their study site, followed by the juveniles, then most of the adult
plants. The cycad aulacaspis scale is unusual in that it also infests
the roots of its host plant at depths of up to 24 in (60 cm) in the
soil (University of Florida 2014, in litt.). Marler and Lawrence (2012,
pp. 238, 240) predict that if the predation by cycad aulacaspis scale
is unabated, it will cause the extirpation of C. micronesica from
western Guam by 2019.
Nonnative specialist arthropods like the cycad aulacaspis scale are
particularly harmful to native plants when introduced to small insular
oceanic islands because the native plants lack the shared evolutionary
history with arthropods and have not developed resistance mechanisms
(Elton 1958 in Marler and Lawrence 2012, p. 233), and the nonnative
arthropods are not constrained by the natural pressures or predators of
their native range (Howard et al. 1999, p. 26; Keane and Crawely 2002
in Marler and Lawrence 2012, p. 233). In addition, C. micronesica is
the sole native host of the cycad aulacaspis scale on Guam, which
raises concerns to biologists who predict that the extirpation of C.
micronesica from Guam will bring about negative cascading ecosystem
responses and manifold ecological changes (Marler and Lawrence 2012, p.
233). Because this scale spread to Rota in 2006 (Moore et al. 2006, in
litt.), and the larger islands of Palau in 2008 (Marler in Science
Daily 2012, in litt.), the same degree of negative impact to C.
micronesica in these areas is likely to occur.
As shown in other case studies worldwide, the scale insects are
known to spread rapidly, within a few months, from the site of
introduction (University of Florida 2014, in litt.). Although the scale
is present on the larger islands of Palau, it has not yet reached the
numerous smaller Rock Islands, where more than 1,000 individuals of C.
micronesica are estimated to occur. As scales can be wind dispersed, it
could be a short amount time for infestation in the Rock Islands, as
shown by its rapid spread throughout Florida between 1996 and 1998
(Marler 2014, in litt.; University of Florida 2014, in litt). The Rock
Islands are a popular tourist destination, and the scale could also be
inadvertently transported on plant material and soils (International
Coral Reef Action Network (ICRAN) 2014, in litt.). Yap is an
intermediate stop-over point for those traveling between Guam and
Palau. Cycas micronesica on Yap are also considered at risk as scales
can be spread by wind dispersal and on transportation of already
infested plant material and soil; and because of the rapidity with
which it spreads (ISSG-GISD 2014, in litt.; University of Florida 2014,
in litt.). In addition, three other insects (a nonnative butterfly
(Chilades pandava), a nonnative leaf miner (Erechthias sp.), and a
native stem borer (Dihammus marianarum), opportunistically feed on C.
micronesica weakened by the cycad aulacaspis scale, compounding its
negative impacts (Marler 2013, pp. 1,334-1,336).
Scales, once established, require persistent control efforts (Gill
2012, in litt.; University of Florida 2014, in litt.). Within the
native range of the scale in southeast Asia, cycads are not affected,
as the scale is kept in check by native predators; however, there are
no predators of the scale in areas where it is newly introduced (Howard
et al. 1999, p. 15). Release of biocontrols has been attempted to abate
the scale infestation; however, these were unsuccessful: Rhyzobius
lophanthae in 2004, which established immediately; Coccobius fulvus in
2005, which did not establish; and Aphytis lignanensis in 2012, which
died in the laboratory prior to release (Moore et al. 2006, in litt.).
Rhyzobius lophanthae prolonged the survival of many Cycas trees during
the first 6 years of scale infestation; however, with time, the size
difference between the scale and R. lophanthae proved to be a problem
when it was observed that the scale could find locations on the Cycas
plant body that the predator (R. lophanthae) could not access (Marler
and Moore 2010, p. 838). Even with this biocontrol, Cycas micronesica
populations are still declining and no reproduction has been observed
on Guam since 2005 (Moore et al. 2006, in litt.).
Ant Predation on Butterflies--Four species of nonnative ants have
been observed to prey upon the Mariana eight-spot butterfly (Schreiner
and Nafus 1996, p. 3), and are believed to also negatively impact the
Mariana wandering butterfly, the two butterfly species listed as
endangered species in this final rule: (1) Dwarf pedicel ants (Tapinoma
minutum); (2) tropical fire ants (Solenopsis geminata); (3) white-
footed ants (Technomyrmex albipes); and (4) bi-colored trailing ants
(Monomorium floricola). These ants eat the butterfly eggs (Schreiner
and Nafus 1996, p. 3; Rubinoff 2014, in litt.). Many ant species are
known to prey on all immature stages of Lepidoptera and can completely
exterminate populations (Zimmerman 1958). In a 1-year study, Schreiner
and Nafus (1996, pp. 3-4) found predation by nonnative ants to be one
of the primary causes of mortality (more than 90 percent) in the
Mariana eight-spot butterfly. These four ant species occur on the
islands of Guam, Rota, and Saipan, which support the two butterfly
species. Biologists observed high mortality of the instar larval stages
of the Mariana eight-spot butterfly (Schreiner and Nafus 1996, pp. 2-
4), for unknown reasons, but this, compounded with predation of eggs by
ants, negatively impacts both the Mariana eight-spot butterfly and the
Mariana wandering butterfly.
Parasitic Wasp Predation on Butterflies--Two native parasitoid
wasps, Telenomus sp. (no common name) and Ooencyrtus sp. (no common
name), are known to lay their eggs in eggs of native Mariana Islands
Lepidoptera species (Mariana eight-spot butterfly (Guam and Saipan) and
[[Page 59467]]
Mariana wandering butterfly (Guam and Rota) (Schreiner and Nafus 1996,
pp. 2-5). These wasps are tiny and likely hitch-hiked with adult female
butterflies in order to access freshly laid eggs, as has been observed
in related species (Woelke 2008, pp. 1-27). These wasps negatively
impact the Mariana eight-spot and Mariana wandering butterflies because
they lay their own eggs within the butterfly eggs, thus preventing
caterpillar development. Habitat destruction and loss of host plants,
along with continued parasitism, act together to negatively affect
populations and individuals of the Mariana eight-spot butterfly and the
Mariana wandering butterfly. These parasitoid wasps occur on the three
islands (Guam, Rota, and Saipan) that support the Mariana eight-spot
butterfly and the Mariana wandering butterfly listed as endangered
species in this final rule.
Conservation Efforts To Reduce Disease or Predation
Conservation efforts to reduce predation are the same as those
mentioned under Factor A. Habitat Destruction, Modification, or
Curtailment of Its Range (see ``Conservation Efforts to Reduce Habitat
Destruction, Modification, or Curtailment of Its Range,'' above).
Additionally, there have been five fenced 1-ac (0.5-ha) exclosures
erected on Tinian as of 2013, each planted with 1,000 individuals of
mature Cycas micronesica (DON 2014, in litt.). Precautions were taken
to ensure plantings had broad genetic representation. Cycads within
these exclosures actively managed to ensure health and survival.
Funding has been programmed to support this project through 2020.
Tinian was selected for these exclosures since the scale does not occur
on this island.
Summary of Disease and Predation
We are unaware of any information that indicates that disease is a
threat to any of the 23 species addressed in this final rule.
Although conservation measures are in place in some areas where one
or more of the 23 Mariana Islands species occurs, our information does
not indicate that they are ameliorating the threat of predation
described above. Therefore, we consider predation and herbivory by
nonnative animal species (pigs, deer, rats, brown treesnakes, monitor
lizards, slugs, flatworms, ants, and wasps) to pose an ongoing threat
to 17 of 23 species addressed in this final rule (see Table 3, above)
throughout their ranges for the following reasons:
(1) Observations and reports have documented that pigs and deer
browse and trample 5 of the 23 plant species (Cycas micronesica,
Eugenia bryanii, Heritiera longipetiolata, Psychotria malaspinae, and
Solanum guamense), and the host plants of the Mariana eight-spot
butterfly, addressed in this rule (see Table 3), in addition to studies
demonstrating the negative impacts of ungulate browsing and trampling
on native plant species of the islands (Spatz and Mueller-Dombois 1973,
p. 874; Diong 1982, pp. 160-161; Cuddihy and Stone 1990, p. 67).
(2) Nonnative rats, snakes, flatworms, and monitor lizards prey
upon one or more of the following six animal species addressed in this
final rule: The Pacific sheath-tailed bat, Slevin's skink, and the four
tree snails.
(3) Ants and wasps prey upon the eggs and larvae of the two
butterflies, the Mariana eight-spot butterfly and Mariana wandering
butterfly.
(4) Nonnative slugs cause mechanical damage to plants and
destruction of plant parts (branches, fruits, and seeds), including
orchids, and are considered a threat to 4 of the 14 plant species in
this rule (Bulbophyllum guamense, Dendrobium guamense, Nervilia
jacksoniae, and Tuberolabium guamense).
(5) Cycas micronesica is currently preyed upon by the cycad
aulacaspis scale on three of the five Micronesian islands (Guam, Rota,
and Palau) on which it occurs (Hill et al. 2004, pp. 274-298; Marler
and Lawrence 2012, p. 233; Marler 2012, pers. comm.). This scale has
the ability to severely impact or even extirpate C. micronesica
throughout its range if not abated.
These threats are serious and ongoing, act in concert with other
threats to the species and their habitats, and are expected to continue
or increase in magnitude and intensity into the future without
effective management actions to control or eradicate them.
Factor D. The Inadequacy of Existing Regulatory Mechanisms
The Mariana Islands encompass two different political entities, the
U.S. Territory of Guam and the U.S. Commonwealth of the Northern
Mariana Islands, and issues regarding existing regulatory measures for
each entity are discussed in separate paragraphs below.
U.S. Territory of Guam
We are aware of regulatory measures regarding conservation of
natural resources established by the Government of Guam. Under Guam
Annotated Rules (GAR) Title 9-Animal Regulations (9 GAR-Animal
Regulations), there are two divisions: (1) Division 1: Care and
Conservation of Animals, and (2) Division 2: Conservation, Hunting and
Fishing Regulations (www.guamcourts.com, accessed February 9, 2014).
Division 1 addresses the importation of animals, animal and zoonotic
disease control, commercial quarantine regulations, and plant and non-
domestic animal quarantine; however, there is no documentation as to
what extent this regulation is enforced. Division 2 Chapter 63 covers
fish, game, forestry, and conservation. Article 2 (sections 63201
through 63208) describe authorities under the Endangered Species Act of
Guam (Guam ESA). This Article vests regulatory power in the Guam
Department of Agriculture. The Guam ESA prohibits, with respect to any
threatened or endangered species of plants or wildlife of Guam and the
United States: (1) Import or export of any such species to or from Guam
and its territory; (2) take of any such species within Guam and its
territory; (3) possession, processing, selling or offering for sale,
delivery, carrying, transport, or shipping, by any means whatsoever,
any such species; provided that any person who has in his possession
such plants or wildlife at the time this provision is enacted into law,
may retain, process, or otherwise dispose of those plants or wildlife
already in his possession, and (4) violation of any regulation or rule
pertaining to the conservation, protections, enhancement, or management
of any designated threatened or endangered species.
As of 2009 (the currently posted list), Guam DAWR recognizes 6 of
the 23 species as endangered (the plant Heritiera longipetiolata; 3 of
the 4 tree snails (the Guam tree snail, the humped tree snail, and the
fragile tree snail), the Pacific sheath-tailed bat, and Slevin's
skink). The other 17 species on Guam listed as threatened or endangered
species in this final rule will be recognized as such and protected by
Guam DAWR under the Endangered Species Act of Guam, as required by the
Act, upon the publication of this final listing rule. However, Guam's
ESA does not address the threats imposed upon the 21 species that occur
currently or historically on Guam that are ongoing and are expected to
increase in magnitude in the near future (Langford's tree snail and the
Rota blue damselfly are the only species addressed in this rule with no
record of occurrence on Guam). Only three species addressed in this
final rule currently benefit from conservation actions on Guam, those
[[Page 59468]]
conducted by the Guam PEPP for Heritiera longipetiolata, Maesa walkeri,
and Psychotria malaspinae, as discussed in ``Conservation Efforts to
Reduce Habitat Destruction, Modification, or Curtailment of Its
Range,'' above. Under Guam's ESA, the Department of Agriculture is
authorized to establish priorities for the conservation and protection
of threatened and endangered species and their associated ecosystems,
but we are unaware of any documentation of these priorities or actions
conducted for protection of the 21 Guam species. If comprehensive
conservation and protection actions are implemented for the 21 Guam
species and their associated ecosystems, it would greatly reduce the
inadequacies outlined above; however, the high costs associated with
curbing problematic nonnative species often precludes the adequate
implementation of such actions to fully address the threats to listed
species.
The capacity of Guam to mitigate the effects of introduced pests
(e.g., brown treesnakes, ungulates, and weeds) is also limited due to
the large number of taxa currently causing damage. Resources available
to reduce the spread of these species and counter their negative
ecological effects are sparse. Despite the fact that Guam receives
assistance from the USDA, U.S. Department of Homeland Security, and
other Federal agencies, the scope of threats remains challenging. Due
to the magnitude and intensity of threats associated with the
introduction of harmful nonnative species in the Marianas (e.g., brown
treesnakes, cycad aulacaspis scale, and the nonnative plant Chromolaena
odorata), the fact that both new and established introduced species
continue to pose a significant problem in Guam leads us to conclude
that current regulatory mechanisms are inadequate to address such
threats.
U.S. Commonwealth of the Northern Mariana Islands (CNMI)
The CNMI has multiple regulatory measures in place intended to
protect natural resources (www.cnmilaw.org, accessed February 9, 2014
(CNMI 2014, in litt.)). Six Chapters under Title 85: Department of Land
and Natural Resources (DLNR) encompass the most relevant regulatory
measures with respect to the 16 CNMI species addressed in this final
rule (www.cnmilaw.org, accessed February 9, 2014). Chapter 85-20
addresses animal quarantine rules and regulations, including domestic
animals of all types, and associated port of entry laws. Chapter 85-30
addresses noncommercial fish and wildlife regulations, including the
List of Protected Wildlife and Plants Species in the CNMI, which
includes 1 of the 23 species addressed in this final rule (the plant
Tabernaemontana rotensis). Species or subspecies listed as threatened
or endangered under CNMI law (Sec. 85-30.1-101 Prohibitions) may not
be harvested, captured, harassed, or propagated except under the terms
of a special permit issued by the Director for scientific purposes, or
for propagation in captivity for the purpose of preservation. A person
who, without a special permit issued in accordance with the regulations
under CNMI law (Sec. 85-30.1-110 Prohibitions), harvests, injures,
imports, exports, captures, or harasses a species or subspecies listed
under CNMI law (Sec. 85-30.1-101), intentionally or not, is in
violation and subject to penalties under Title 2 (Natural Resources)
Commonwealth Code (CMC) Sec. 5109.
Existing regulations are also in place to protect wildlife
conservation areas under CNMI law (Sec. 85-30.1-330), (e.g.,
prohibitions of hunting, fishing, collecting, killing, commercial
activity, destruction of habitats or artifacts, and camping) (CNMI-
DLNR-Rota 2015, in litt.). Chapter 85-60 covers the Division of Plant
Industry, including plant quarantine regulations. Chapter 85-80 covers
the Division of Zoning. Chapter 85-90 addresses permits necessary for
the clearing and burning of vegetation, and removal of plants or plant
products, or soil, from areas designated as diverse forests on public
lands. Chapter 85-100 addresses brown treesnake prevention regulations.
All six chapters under Title 85 mentioned above have a component that
is designed to protect native species, including rare species at risk
from competition and predation by nonnative, and in some cases native,
species. However, these regulations are difficult to enforce due to
lack of funding availability and human resources (CNMI-DLNR-Rota 2015,
in litt.).
Further, the capacity of the CNMI to mitigate the effects of
introduced pests (e.g., nonnative ungulates, brown treesnakes, weeds,
and predatory flatworms) is also limited due to the large number of
taxa currently causing damage. Resources available to reduce the spread
of these species and counter their negative ecological effects are
sparce. Despite the fact that CNMI receives assistance from the USDA,
U.S. Department of Homeland Security, and other Federal agencies, the
scope of threats remains challenging. Due to the magnitude and
intensity of threats associated with the introduction of harmful
nonnative species in the Marianas (e.g., brown treesnakes, cycad
aulacaspis scale, and predatory flatworms) poses a significant threat
to the native species of the Marianas; the fact that both new and
established introduced species continue to pose a significant problem
in the CNMI leads us to conclude that current regulatory mechanisms are
inadequate to address such threats.
Greater enforcement of local laws in place would provide additional
benefit to the 16 species listed as endangered or threatened species in
this final rule that occur in the CNMI (the plants Bulbophyllum
guamense, Cycas micronesica, Dendrobium guamense, Heritiera
longipetiolata, Maesa walkeri, Nervilia jacksoniae, Tabernaemontana
rotensis, and Tuberolabium guamense; the humped tree snail, Langford's
tree snail, and the fragile tree snail; the two butterflies, the
Pacific sheath-tailed bat, Slevin's skink, and the Rota blue
damselfly). However, the magnitude and intensity of threats, combined
with the high costs associated with curbing problematic nonnative
species and the lack of funding and human resources to implement
regulations, preclude the ability of regulatory actions to fully
address the threats to listed species, thus rendering current
regulatory mechanisms inadequate to protect the 16 CNMI species in this
final rule.
U.S. Department of Defense (DOD)
The Sikes Act (16 U.S.C. 670) authorizes the Secretary of Defense
to develop cooperative plans with the Secretaries of Agriculture and
the Interior for natural resources on public lands. The Sikes Act
Improvement Act of 1997 requires Department of Defense installations,
in cooperation with the Service and the State fish and wildlife agency,
to prepare Integrated Natural Resources Management Plans (INRMPs) that
provide for the conservation and rehabilitation of natural resources on
military lands consistent with the use of military installations to
ensure the readiness of the Armed Forces. The Sikes Act states that the
INRMP is to reflect the mutual agreement of the parties concerning
conservation, protection, and management of fish and wildlife
resources. DOD guidance states that mutual agreement should be the goal
for the entire plan, and requires agreement of the Service with respect
to those elements of the plan that are subject to other applicable
legal authority of the Service such as the Endangered Species Act.
In December 2013, the Department of the Navy, JRM, completed an
Integrated Natural Resources Management Plan
[[Page 59469]]
(INRMP) to address the conservation, protection, and management of fish
and wildlife resources on DOD-managed and -controlled areas on Guam,
specifically Naval Base Guam and Andersen Air Force Base, including
leased lands in the CNMI on Tinian and Farallon de Medinilla. On July
2, 2013, the Navy requested the Service's endorsement of the JRM INRMP.
The JRM INRMP is under review by the Service, but at present the Navy
is operating under an INRMP that has not been agreed to by the Service.
The Service's primary concerns include the need to increase efficiency
regarding coordination with Federal and State partners, implement
recovery efforts for extirpated endemic species (several of which exist
only in captive-breeding programs), implement large-scale control and
eradication of brown treesnakes, increase protected lands (e.g.,
conservation areas) in order to recover endangered and threatened
species, implement ungulate control, and increase conservation actions
on Tinian and Farallon de Medinilla. The Service is continuing to work
with the Navy on the development of their INRMP for DOD lands in this
region.
At this time, the actions outlined in the INRMP do not alleviate
the threats to the species addressed in this final rule that occur on
DOD lands as the most current draft of the INRMP (December 2013)
predates the publication of the proposed rule (October 1, 2014). The
December 2013 INRMP (U.S. Navy 2013, p. ES-2) states that ``Several
non-candidate Marianas species are also being considered for evaluation
for inclusion in the proposed rules. Once the USFWS determines which
species will be included in the proposed rules, JRM will develop a
supplemental document for inclusion in the JRM INRMP for those species
with the potential to be on Navy lands. The supplemental document will
also include information on the known status of each species and will
identify projects to be undertaken on JRM lands to manage the long-term
conservation of the species.'' The Service has not received the
supplemental document to make a determination of whether or not the
proposed actions will alleviate the threats to the species in this
final rule that occur on DOD lands.
Multijurisdictional Regulatory Mechanisms
The task of preventing the spread of deleterious nonnative species
requires multijurisdictional efforts. The brown treesnake (BTS)
technical working group (comprising agencies within the U.S. Department
of the Interior (e.g., USFWS, U.S. Geological Survey, National Park
Service), DOD (e.g., JRM and NavFac Pacific), Department of
Transportation (DOT), U.S. Territory of Guam, CNMI, State of Hawaii,
and other nongovernmental partners) designs and implements actions to
address the regulatory mechanisms currently in place (e.g., CNMI:
Administrative Code Chapter 85-20 and Chapter 85-60; Guam: 9 GAR-Animal
Regulations, Division 1: And U.S. Executive Orders 13112 and 13112) to
prevent inadvertent transport of deleterious species (e.g., brown
treesnakes) into Guam and the Mariana Islands, and from Guam to other
areas, which are important efforts that provide some benefits to all 23
species. However, these efforts are not sufficient to eliminate the
continuing threats associated with the brown treesnake in the Marianas.
For example, in 2014, a brown treesnake was captured at the sea port on
Rota (BTS Strategic Plan 2015, p. iii), as described above under Factor
C. Additionally, the BTS Strategic Plan, authored by the BTS technical
working group, states that ``current snake management strategies have
been successful in decreasing, but not eliminating, the probability of
snakes becoming established on other islands (BTS Strategic Plan 2015,
p. iii).''
Summary of the Inadequacy of Existing Regulatory Mechanisms
Both the U.S. Territory of Guam and the U.S. Commonwealth of the
Northern Mariana Islands have regulations in place designed to provide
protection for their respective natural resources, including native
forests, water resources, and the 23 species addressed in this rule;
however, enforcement of these regulations is not documented. Greater
enforcement of local laws in place would provide additional benefit to
the 23 species; however, the magnitude and intensity of threats, the
high costs associated with curbing problematic nonnative species, and
the lack of funding and human resources to implement such regulations
preclude the ability of current regulatory mechanisms to fully address
the threats to the 23 species in this final rule. The conservation
actions proposed in the 2013 INRMP do not address the 23 Mariana
Islands species in this final rule, as the INRMP predates the proposed
listing rule (October 2014). The JRM is currently drafting a supplement
that will address the threats imposed upon the 23 species that occur on
DOD lands; however, the Service has not yet received this document. The
multi-agency BTS technical working group aims to prevent inadvertent
transport of deleterious species (the brown treesnake) into Guam and
the Mariana Islands, and from Guam to other areas, and although these
efforts are important and provide some benefits to all 23 species, they
are not sufficient to eliminate the continuing threats associated with
the brown treesnake in the Marianas.
Factor E. Other Natural or Manmade Factors Affecting Their Continued
Existence
Other factors that pose threats to some or all of the 23 species
include ordnance and live-fire training, water extraction, recreational
off-road vehicles, and small numbers of populations and small
population sizes. Each threat is discussed in detail below, along with
identification of which species are affected by these threats.
Ordnance and Live-Fire Training
Several individuals of the plants Cycas micronesica, Psychotria
malaspinae, and Tabernaemontana rotensis, and the Mariana eight-spot
butterfly, listed as threatened or endangered species in this rule, are
located on the Northwest Field of Andersen AFB and the Guam National
Wildlife Refuge within the boundaries of the preferred site for a new
live-fire training range complex proposed in the 2015 Final SEIS for
the Guam and CNMI Military Relocation (JGPO-NavFac, Pacific 2015, pp.
ES-1--ES-40). This live-fire training range complex will consist of 5
live-fire training ranges and associated range control facilities and
access roads (JGPO-NavFac, Pacific 2014, p. ES-5; JGPO-NavFac, Pacific
2015, pp. ES-5, ES-11). Once developed, military training is expected
to be conducted within the 5 live-fire training ranges (including a
multipurpose machine gun range), for 39 weeks out of the year, with 2
night-trainings per week (JGPO-NavFac, Pacific 2014, pp. ES-1, ES-5,
and Figure 2.5-6). Depending on the type of ammunition used, there
could be substantial damage to vegetation, or a possible fire started
from ordnance use, which could destroy individuals of Cycas
micronesica, Psychotria malaspinae, and Tabernaemontana rotensis, and
the Mariana eight-spot butterfly, and their habitat.
Live-fire training is also proposed for the entire northern half of
Pagan and on northern Tinian (see ``Historical and Ongoing Human
Impacts,'' above (CJMT Draft EIS-OEIS http://www.cnmijointmilitarytrainingeis.com/about). Similarly, as described
above, ordnance and live-fire training are a threat to the species
addressed in this rule that occur on Tinian (Heritiera longipetiolata
and
[[Page 59470]]
the humped tree snail) and Pagan (humped tree snail and Slevin's
skink). Additionally, we believe there may be a small population of
Cycas micronesica on Pagan; however, this is not yet confirmed. Direct
damage to individuals from live-fire and ordnance has already been
documented in the past for the plants Cycas micronesica and Heritiera
longipetiolata along the Tarague ridgeline (GDAWR 2013, in litt.). On
the Tarague ridgeline near an existing firing range on Andersen AFB,
ricochet bullets and ordnance have broken branches and made holes
through parts of Cycas micronesica and Heritiera longipetiolata trees,
causing added stress and a possible avenue for disease (Guam DAWR 2013,
pers. comm.). Although there is a buffer zone at the end of this firing
range, there is not a buffer zone on either side, thus increasing the
risk of damage to nearby forests. In 2014, DON biologists conducted a
site visit to the Tarague ridgeline and reported they were unable to
detect any damage to the individuals of C. micronesica and H.
longipetiolata present in this area, concluding the trees must have
healed from their wounds (DON 2014, in litt.). We consider ordnance and
live-fire training a direct threat to individuals of the plants Cycas
micronesica, Heritiera longipetiolata, Psychotria malaspinae, and
Tabernaemontana rotensis; and to the humped tree snail, Mariana eight-
spot butterfly, and Slevin's skink. Additionally, we consider ordnance
and live-fire a threat to these species due to the associated risk from
fires caused by ordnance and live-fire training.
Water Extraction
The Rota blue damselfly was only first discovered in April 1996,
outside the Talakhaya Water Cave (also known as Sonson Water Cave)
located below the Sabana plateau on the island of Rota (see the
species' description, above) (Polhemus et al. 2000, pp. 1-8; Camacho et
al. 1997, p. 4). The Talakhaya Water Cave, As Onon Spring, and the
perennial stream formed from runoff from the springs at the Water Cave
support the only known population of the Rota blue damselfly. Rota's
municipal water is obtained by gravity flow from these two springs (up
to 1.8 Mgal/day) (Keel et al. 2007, pp. 1, 5; Stafford et al. 2002, p.
17). Under ordinary climatic conditions, this area supplies water in
excess of demand but El Ni[ntilde]o-Southern Oscillation (ENSO)-induced
drought conditions can lead to significantly reduced discharge, or may
completely dewater the streams (Keel et al. 2007, pp. 3, 6, 19). In
1998, water captured from the springs was inadequate for municipal use,
and water rationing was instituted (Keel et al. 2007, p. 6). As the
annual temperature rises resulting from global climate change, other
weather regime changes such as increases in droughts, floods, and
typhoons will occur (Giambelluca et al. 1991, p. iii). Increasing night
temperatures cause a change in mean precipitation, with increased
occurrences of drought cycles (Loope and Giambelluca 1998, pp. 514-515;
Emanuel et al. 2008, p. 365; U.S. Global Change Research Program (US-
GCRP) 2009, pp. 145-149, 153; Keener et al. 2010, pp. 25-28; Finucane
et al. 2012, pp. 23-26; Keener et al. 2012, pp. 47-51). The limestone
substrate of Rota is porous, with filtration through the central Sabana
being the sole water source for the few streams on the island and for
human use. There are no other groundwater supplies on the island, and
storage capacity is limited. The Rota blue damselfly is dependent upon
any water that escapes the Talakhaya Springs naturally, beyond what has
not already been removed for human use.
The likelihood of dewatering of the Talakhaya Springs is high due
to climate change causing increased ENSO conditions, and increased
human demand. The ``Public and Agency Participation'' section of the
Comprehensive Wildlife Conservation Strategy for the Commonwealth of
the Northern Mariana Islands (2005, p. 347) cites ``individuals state
the Department of Public Works has been increasing their water
extraction from Rota's spring/stream systems. Historically, this water
source flowed year-around, yet now they are essentially dry most of
each year'' (see the species description ``Rota blue damselfly,''
above; and ``Stream Ecosystem,'' in the proposed rule (79 FR 59364;
October 1, 2014), for further discussion). Water extraction is an
ongoing threat to the Rota blue damselfly. The loss of this perennial
stream would remove the only known breeding and foraging habitat of the
sole known population of the Rota blue damselfly, thereby likely
leading to its extinction.
Recreational Vehicles
The savanna areas of Guam are popular for use of recreational
vehicles. Damage and destruction caused by these vehicles are a direct
threat to the plants Hedyotis megalantha and Phyllanthus saffordii,
listed as endangered species in this final rule, as well as a threat to
the savanna habitat that supports these plant species (Gutierrez 2013,
in litt.; Guam DAWR 2013, pers. comm.). Hedyotis megalantha and P.
saffordii are particularly at risk, as the only known individuals of
these species are scattered on the savanna and local biologists have
observed recreational vehicle tracks directly adjacent to these two
species (Gutierrez 2013, in litt.; Guam DAWR 2013, pers. comm.).
Small Numbers of Individuals and Populations
Species that are endemic to single islands are inherently more
vulnerable to extinction than are widespread species, because of the
increased risk of genetic bottlenecks, random demographic fluctuations,
climate change effects, and localized catastrophes, such as typhoons
and disease outbreaks (Pimm et al. 1988, p. 757; Mangel and Tier 1994,
p. 607). These problems are further magnified when populations are few
and restricted to a very small geographic area, and when the number of
individuals in each population is very small. Species with these
population characteristics face an increased likelihood of extinction
due to changes in demography, the environment, genetic bottlenecks, or
other factors (Gilpin and Soul[eacute] 1986, pp. 24-34). Small,
isolated populations often exhibit reduced levels of genetic
variability, which diminishes the species' capacity to adapt and
respond to environmental changes, thereby lessening the probability of
long-term persistence (Barrett and Kohn 1991, p. 4; Newman and Pilson
1997, p. 361). Very small, isolated populations are also more
susceptible to reduced reproductive vigor due to ineffective
pollination (plants), inbreeding depression (plants and animals), and
hybridization (plants and insects). The problems associated with small
population size and vulnerability to random demographic fluctuations or
natural catastrophes are further magnified by synergistic interactions
with other threats, such as those discussed above (see Factor A. The
Present or Threatened Destruction, Modification, or Curtailment of Its
Habitat or Range and Factor C. Disease or Predation, above).
The following 3 plant species have a very limited number of
individuals (fewer than 50) in the wild: Psychotria malaspinae, Solanum
guamense, and Tinospora homosepala. We consider these species highly
vulnerable to extinction due to threats associated with small
population size or small number of populations because:
The only known occurrences of Psychotria malaspinae,
Solanum guamense, and Tinospora homosepala are threatened either by
ungulates, rats, brown treesnake, nonnative plants, fire, or a
combination of these. Furthermore, Tinospora homosepala may no longer
[[Page 59471]]
be able to sexually reproduce, as the only known remaining individuals
of this species all appear to be male.
Psychotria malaspinae is known from fewer than 10
scattered individuals, and Solanum guamense is known from a single
individual (Yoshioka 2008, p. 15; Cook 2012, in litt.; CPH 2012f--
Online Herbarium Database; Harrington et al. 2012, in litt.; Grimm
2013, in litt.; Rogers 2012, in litt.; WCSP 2012d--Online Herbarium
Database).
Animals--Like most native island biota, the single island endemics
Guam tree snail, Langford's tree snail, and Rota blue damselfly are
particularly sensitive to disturbances due to low number of
individuals, low population numbers, and small geographic ranges.
Additionally, the fragile tree snail, Mariana eight-spot butterfly,
Mariana wandering butterfly, and Pacific sheath-tailed bat (Mariana
subspecies) each have a low number of populations, even though they
historically occurred on two or more islands within the Marianas
Archipelago. Current data indicate that the only known remaining
individuals of the Mariana eight-spot butterfly occur on Guam, there
are no known individuals of the Mariana wandering butterfly on Guam or
Rota, and the Pacific sheath-tailed bat (Mariana subspecies) now occurs
only on Aguiguan. The fragile tree snail occurs in low number of
populations on Guam (two populations) and Rota (one population).
Furthermore, recent genetic analyses conducted on the fragile tree
snail, Guam tree snail, and Mariana eight-spot butterfly on Guam show
that the fragile tree snail and the Mariana eight-spot butterfly have
no heterogeneity, even between different populations, rendering these
species highly vulnerable to the negative effects associated with loss
of genetic diversity. The Guam tree snail has a very low level of
genetic diversity, but not enough to consider it exempt from the
threats associated with low numbers (Lindstrom and Benedict 2014, pp.
26-27).
We consider these 10 species to be especially vulnerable to
extinction due to either low number of individuals or low number of
populations, or both; because these species occur on single islands, or
only two neighboring islands; are declining in number of individuals
and range; have low or no detectable genetic diversity; and are
consequently vulnerable and at risk from one or more of the following
threats: Predation by nonnative rats, monitor lizards, and flatworms;
habitat degradation and destruction by nonnative ungulates; fire;
typhoons; drought; and water extraction (see Factor A. The Present or
Threatened Destruction, Modification, or Curtailment of Its Habitat or
Range and Factor C. Disease or Predation, above).
Conservation Efforts To Reduce Other Natural or Manmade Factors
Affecting Its Continued Existence
We are unaware of any conservation actions planned or implemented
at this time to abate the threats to the species negatively impacted by
ordnance and live-fire (the plants Cycas micronesica, Heritiera
longipetiolata, and Psychotria malaspinae; and the humped tree snail,
Mariana eight-spot butterfly, and Slevin's skink); water extraction
(Rota blue damselfly), recreational vehicles (Hedyotis megalantha and
Phyllanthus saffordii), or low numbers (the plants Psychotria
malaspinae, Solanum guamense, and Tinospora homosepala; the fragile
tree snail, Guam tree snail, and Langford's tree snail; the Mariana
eight-spot butterfly and Mariana wandering butterfly; and the Rota blue
damselfly).
Summary of Other Natural or Manmade Factors Affecting Their Continued
Existence
We consider the threat from ordnance and live-fire training to be a
serious and ongoing threat for four plant and three animal species
addressed in this final rule (the plants Cycas micronesica, Heritiera
longipetiolata, Psychotria malaspinae, and Tabernaemontana rotensis;
and the humped tree snail, Mariana eight-spot butterfly, and Slevin's
skink), because direct damage to individual plants and animals may be
fatal, or cause enough damage to render them more vulnerable to other
threats. We consider the threat from water extraction to be a serious
and ongoing threat for the Rota blue damselfly because the spring that
supplies Rota's municipal water is also the spring that supports the
primary population of the only two known occurrences of the species. We
consider recreational off-road vehicles a threat to the plants Hedyotis
megalantha and Phyllanthus saffordii because off-road vehicles can
damage individual plants and destroy the habitat that supports these
two species.
We consider the threat from limited numbers of populations and low
numbers of individuals (fewer than 50) to be serious and ongoing for 3
plant species addressed in this final rule (Psychotria malaspinae,
Solanum guamense, and Tinospora homosepala) because: (1) These species
may experience reduced reproductive vigor due to ineffective
pollination or inbreeding depression; (2) they may experience reduced
levels of genetic variability, leading to diminished capacity to adapt
and respond to environmental changes, thereby lessening the probability
of long-term persistence; and (3) a single catastrophic event (e.g.,
fire) may result in extirpation of remaining populations and extinction
of the species. This threat applies to the entire range of each
species.
The threat to the fragile tree snail, Guam tree snail, Langford's
tree snail, Mariana eight-spot butterfly, Mariana wandering butterfly,
Pacific sheath-tailed bat (Marianas subspecies), and Rota blue
damselfly from limited numbers of individuals and populations is
ongoing and is expected to continue into the future because population
numbers of these species are so low that: (1) They may experience
reduced reproductive vigor due to inbreeding depression; (2) they may
experience reduced levels of genetic variability leading to diminished
capacity to adapt and respond to environmental changes, thereby
lessening the probability of long-term persistence; (3) a single
catastrophic event, whether of anthropogenic or natural origin (e.g.,
super typhoon), may result in extirpation of remaining populations and
extinction of these species; and (4) species with few known locations
are less resilient to threats that might otherwise have a relatively
minor impact on widely distributed species. For example, an increase in
predation of these species that might be absorbed in a widely
distributed species could result in a significant decrease in
survivorship or reproduction of a species with limited distribution.
Additionally, the limited distribution of these species magnifies the
severity of the impact of the other threats discussed in this final
rule.
Summary of Factors
The primary factors that pose serious and ongoing threats to 1 or
more of the 23 species throughout all or a significant portion of their
ranges in this final rule include:
Habitat degradation and destruction by development;
activities associated with military training and urbanization;
nonnative ungulates and plants; rats; brown treesnakes; fire; typhoons;
and the interaction of these threats with the projected effects of
climate change (Factor A);
Overutilization of tree snails due to collection for trade
or market (Factor B);
Predation or herbivory by nonnative animal species
(ungulates, deer, rats, brown treesnakes, monitor lizards,
[[Page 59472]]
slugs, flatworms, ants, and wasps) (Factor C);
Inadequate existing regulatory mechanisms to address the
spread or control of nonnative species (Factor D); and
Other natural or manmade factors, including impacts from
ordnance and live-fire training, water extraction, recreational
vehicles, and increased vulnerability to extinction as a consequence of
these threats due to limited numbers of populations and individuals
(Factor E).
While we acknowledge that the voluntary conservation measures
described above may help to ameliorate some of the threats to the 23
species addressed in this final rule, these conservation measures are
not sufficient to control or eradicate these threats to the point that
these species do not meet the definition of threatened or endangered
under the Act.
Summary of Comments and Recommendations
On October 1, 2014, we published a proposed rule to list 23 species
(14 plants, 4 tree snails, 2 butterflies, 1 bat, 1 skink, and 1
damselfly) as endangered or threatened species throughout their ranges
(79 FR 59364). The comment period for the proposal opened on October 1,
2014, for 60 days, ending on December 1, 2014. We requested that all
interested parties submit comments or information concerning the
proposed rule. We contacted all appropriate State and Federal agencies,
county governments, elected officials, scientific organizations, and
other interested parties and invited them to comment. In addition, we
published a public notice of the proposed rule on October 20, 2014, in
the local Marianas Variety Guam Edition, Marianas Variety, and Pacific
Daily News, at the beginning of the comment period. We received two
requests for public hearings. On January 12, 2015, we published a
notice (80 FR 1491) reopening the comment period on the October 1,
2014, proposed rule (7959364), for an additional 30 days in order to
allow interested parties more time for comments on the proposed rule.
In that same document (80 FR 1491; January 12, 2015), we announced two
public hearings, each preceded by a public information meeting, as well
as two separate public information meetings, for a total of four public
information meetings altogether. The two public hearings preceded by
public information meetings were held in the U.S. Territory of Guam
(Guam) on January 27, 2015; and the U.S. Commonwealth of the Northern
Mariana Islands (CNMI) (Saipan) on January 28, 2015. The two separate
public information meetings were held on the islands of Rota (CNMI) on
January 29, 2015; and Tinian (CNMI) on January 31, 2015.
During the comment periods, we received 23 comment letters,
including 9 peer review comment letters, on the proposed listing of the
23 Mariana Island species. In this final rule, we address only those
comments directly relevant to the proposed listing of 23 species in
Guam and the CNMI. We received several comments that were not germane
to the proposed listing of 23 species (for example, suggestions for
future recovery actions should the species be listed); such comments
are not addressed in this final rule.
Three comment letters were from the CNMI Department of Land and
Natural Resources (DLNR); one was from a representative in the CNMI
legislature; two were from Guam government agencies (Guam Department of
Agriculture, Division of Aquatic and Wildlife Resources (GDAWR); and
Guam Bureau of Statistics and Planning); two were from Federal agencies
(National Park Service and U.S. Navy); and six were from
nongovernmental organizations or individuals. Nine letters were
responses from requested peer reviews. The CNMI DLNR and one public
commenter requested a public hearing and extension of the comment
period. In response, we reopened the comment period for 30 days, from
January 12, 2015, to February 11, 2015. In addition, during the public
hearings held on January 27, 2015 (Guam), and January 28, 2015
(Saipan), seven individuals or organizations made oral comments on the
proposed listing.
All substantive information related to the listing of the 23
species provided during the comment periods, including technical or
editorial corrections, has either been incorporated directly into this
document or is addressed below (also see Summary of Changes from the
Proposed Rule, above). Comments received were grouped into general
issues specifically relating to the proposed listing status of the 14
plants, the 4 tree snails, the 2 butterflies, the bat, the skink, or
the damselfly, and are addressed in the following summary and
incorporated into the final rule as appropriate.
Peer Review
In accordance with our peer review policy published in the Federal
Register on July 1, 1994 (59 FR 34270), we solicited expert opinions
from 21 knowledgeable individuals with scientific expertise on the
Mariana Islands plants, tree snails, butterflies, bat, skink, and
damselfly, and their habitats, including familiarity with the species,
the geographic region in which these species occur, and principles of
conservation biology. We received responses from nine of these peer
reviewers. Eight of the nine peer reviewers supported our methods and
conclusions, and one peer reviewer solely provided corrections to local
common names. Four peer reviewers noted particular agreement with our
evaluation of the scientific data informing our assessment of the
conservation status of support for the listing of the four tree snails,
and concurred with the associated status and threat assessments.
Similarly, two peer reviewers noted particular agreement with our
status assessment for the two butterflies; two peer reviewers noted
particular support for the assessment of the bat; and one peer reviewer
noted particular support for the assessment of the skink. We reviewed
all comments received from the peer reviewers for substantive issues
and new information regarding the listing of 23 species. All nine
reviewers provided information on one or more of the Mariana Islands
species, which was incorporated into this final rule (see also Summary
of Changes from Proposed Rule). Several of the peer reviewers
specifically commented that the proposed rule represented an exhaustive
and largely accurate (barring some relatively minor corrections)
assessment of the status and threats to the species; we did not receive
any peer reviews that took general issue with the scientific rigor of
our evaluation. Peer reviewer comments are addressed in the following
summary and incorporated into the final rule as appropriate.
Peer Review General Comments
(1) Comment: One peer reviewer commented that many of the Chamorro
names of the animals and plants listed in the proposed rule either do
not conform to accepted orthography of the language or appear
incorrect, and provided corrections for select species.
Our Response: After the publication of the proposed rule, we
solicited the guidance from a local language specialist to ensure
proper use of Chamorro and Carolinian common names in all our documents
regarding the 23 species, and to translate some of our public outreach
material disseminated at the two public hearings (Guam and Saipan) and
four public information meetings (Guam, Saipan, Rota, and Tinian) held
in January 2015. We have incorporated all of the recommended changes to
the Chamorro
[[Page 59473]]
and Carolinian common names for plants and animals under Table 1 and
Summary of the 23 Species, above; and noted this change under Summary
of Changes from the Proposed Rule, above. However, due to past
complications with attempts to use diacritical marks in our rules, we
have elected not to print them here. Please see Kerr (2014, in litt.)
and USFWS (2015, in litt.) for the Chamorro and Carolinian names of
plants and animals addressed in this final rule, with the proper
diacritical marks. Additionally, the language expert we consulted did
not change the spelling of Chamorro to Chamoru, as suggested by Kerr
(2014, in litt.), so we retained the use of Chamorro for this final
rule.
(2) Comment: One peer reviewer commented that the proposed rule
does not take into account information from Candidate Species surveys
carried out by University of Guam (UOG) and University of Hawaii (UH)
research biologists in 2013, and cited Lindstrom and Benedict 2014.
Our Response: We have incorporated all new relevant information
from the 2013 candidate species surveys conducted by UOG and UH
biologists (Lindstrom and Benedict 2014, pp. 1-44, and Appendices A-E)
under Description of the 23 Mariana Islands Species and Summary of
Biological Status and Threats Affecting the 23 Mariana Islands Species,
above.
(3) Comment: One peer reviewer expressed confusion regarding the
relationship between predation and herbivory under Factor C. Disease
and Predation, above.
Our Response: The term ``predation'' comes directly from the
statutory language used in the identification of Factor C under section
4(a)(1) of the Act, which refers to the potential threat of ``disease
and predation.'' In our discussions under Factor C, we use the term
``herbivory'' as analogous to predation, but our choice of terminology
depends on the subject of the action. In general, we use the term
herbivory if the subject being eaten is a plant, and the term predation
if the subject being eaten is an animal.
(4) Comment: One peer reviewer stated that it is not clear what an
`ecosystem focus' means or how it would be implemented, particularly if
a species occurs in more than one ecosystem.
Our Response: The ecosystem approach allows us to assess and
protect each individual species in need of conservation, whether that
species occurs in a single ecosystem or multiple ecosystems, but to
organize our rule in a more efficient manner. For each species under
consideration for listing as a threatened species or endangered species
under the Act, we must evaluate the threats to that species under a
common ``5-factor'' framework as required by the statute. Specifically,
the Act mandates us to consider whether a species may be a threatened
species or endangered species because of any of the following factors:
(A) The present or threatened destruction, modification, or curtailment
of its habitat or range; (B) Overutilization for commercial,
recreational, scientific, or educational purposes; (C) Disease or
predation; (D) The inadequacy of existing regulatory mechanisms; or (E)
Other natural or manmade factors affecting its continued existence.
When species share the same ecosystem, they often have similar life-
history requirements and experience the same threats. Grouping these
species by shared ecosystems allows us to evaluate the threats shared
by these species in a more efficient way and reduce repetition for the
reader. Each species is still considered on a strictly individual basis
as to whether or not it warrants listing.
If an individual species is determined to meet the definition of a
threatened species or endangered species under the Act, subsequent to
listing that species will be the subject of a recovery plan. In the
recovery phase, it is our intention that the ecosystem approach will be
beneficial in terms of allowing us to focus on restoring all of the
components within a particular ecosystem to its optimal health and
functionality, which will support not only one or a few species of
particular interest, but all native species within that ecosystem (for
example, control of feral pigs would benefit all native species within
a shared ecosystem). This approach should ultimately protect other
vulnerable species that may otherwise need listing in the future as
well, and is consistent with the stated purpose of the Act ``to provide
a means whereby the ecosystems upon which endangered species and
threatened species depend may be conserved.''
(5) Comment: Two peer reviewers expressed concern regarding the
proposed military actions on Pagan, and the associated negative impacts
these actions will have on one or more of the 23 species. One of these
peer reviewers stated that either of the two butterflies, either the
Mariana wandering butterfly or the Mariana eight-spot butterfly, may
occur on Pagan.
Our Response: The potential for future military actions on Guam and
the CNMI is one of the threats we considered in making the listing
determinations finalized in this document. As discussed in the section
Summary of Biological Status and Threats Affecting the 23 Mariana
Islands Species, we consider military actions on Pagan likely to
negatively impact the humped tree snail and the Marianas skink, as well
as any other of the 23 species that may occur on Pagan but have not yet
been discovered or confirmed (e.g., Cycas micronesica or the two
butterflies).
(6) Comment: One peer reviewer stated that it is important to
protect the humped tree snail and fragile tree snail at their known
population sites on Guam (Haputo Ecological Reserve Area (HERA) and
Hilaan), as well as the Mariana eight-spot butterfly and its host
plants) from feral ungulates and human development, military and
otherwise. Additionally, the reviewer suggested that we must protect
all areas with potential habitat and sites of the host plants, not just
the karst towers towards the cliff lines.
Our Response: The Service appreciates support for the conservation
of the tree snails and butterflies addressed in this final rule and the
concurrence regarding the threats associated with ungulates and human
development on these species. These suggestions will be taken into
account as we move forward with recovery planning and implementation
for these species.
Peer Review Comments on the Two Butterflies
(7) Comment: One peer reviewer commented that extensive surveys
indicate that ungulate browsing has reduced the range of the two host
plants for the Mariana eight-spot butterfly to only the most rugged
karst within the forest ecosystem, and when one of these plants grows
long enough to outreach the protection of the karst, browsing damage is
usually observed. Additionally, this peer reviewer stated that the two
host plants have been observed on Saipan as recently as 2011, which
provides a more recent observation than what was cited in the proposed
rule, and suggests that it is possible that the Mariana eight-spot
butterfly may still occur on this island in small numbers.
Our Response: We have added this information to Description of the
23 Mariana Islands Species, above.
(8) Comment: One peer reviewer commented that recent surveys were
conducted for the Mariana wandering butterfly on Tinian, Saipan, and
Rota earlier this year, as well as Guam. The host plant (Maytenus
thompsonii) was even more abundant than what Global Positioning Systems
(GPS) data
[[Page 59474]]
reflected; however, not a single individual of the Mariana wandering
butterfly was observed.
Our Response: We appreciate being provided the most up-to-date
survey data for the Mariana wandering butterfly on Guam, Rota, Tinian,
and Saipan; and have added any new data under Description of the 23
Mariana Islands Species, above.
(9) Comment: Two peer reviewers stated that small populations of
either of the two butterflies may occur on other islands previously
unreported if suitable habitat exists, or may remain in small obscure
populations on islands where they have been known to occur but have not
been observed for many years.
Our Response: We agree that the best available information
indicates that the two butterflies may exist in small, undetected, and
obscure populations within their known ranges, or may possibly be on
other islands within the Mariana Archipelago that provide suitable
habitat, but where they have not yet been observed. We have added this
information under Description of the 23 Mariana Islands Species, above.
As this information is purely speculative, however, we did not consider
it in our final determination.
Peer Review Comments on the Tree Snails
(10) Comment: One peer reviewer commented that shell collecting
does not appear to be a current threat to the four tree snails. The
CNMI Department of Land and Natural Resources (DLNR) made a similar
comment, noting that the DLNR Division of Fish and Wildlife recently
conducted a threat assessment for partulid snails in the CNMI in
consultation with regional snail experts and concluded that shell
collecting was not a threat to any snail population in the CNMI.
Our Response: Based on the best available information, the Service
has concluded that collection of tree snail species is an ongoing
threat to tree snail species around the globe, including in the Mariana
Islands, where the Service has recently observed jewelry (bracelets and
necklaces) made from tree snails (USFWS 2012, in litt.). Given the
rarity of the tree snail species considered here, the potential
collection of even a few individuals could have serious consequences
for the population.
(11) Comment: A survey in 2013 found a small number of humped tree
snails in an isolated spot on Tinian.
Our Response: We have updated this final rule to incorporate the
new location data of the humped tree snail on Tinian. This new
information is significant, since at the time of the proposed rule we
did not have information to suggest that the humped tree snail was
still found on that island.
(12) Comment: One peer reviewer commented that it was difficult to
understand how the brown treesnake poses a threat to the four tree
snails.
Our Response: We have attempted to clarify the nature of the threat
posed by the brown treesnake to the tree snails in this final rule. The
brown treesnake is not a direct threat to the four tree snails, but we
conclude it poses an indirect threat to these species through
alteration or degradation of habitat. The brown treesnake has been
shown to alter forest structure as a secondary impact resulting from
direct predation on native birds, which many native trees rely upon for
seed dispersal (Rogers 2008, in litt.; Rogers 2009, in litt.). By
interfering with the natural seed dispersal mechanism provided by
native birds, the actions of the brown treesnake change the
distribution, species composition, and ultimately the structure of the
forest. The alteration of forest structure subsequently alters the
microclimate requirements necessary to support tree snails on Guam, and
other islands in the Marianas, ultimately degrading habitat quality and
availability for the tree snails.
(13) Comment: Two peer reviewers provided new information regarding
the status of the fragile tree snail on Guam, and specifically the
confirmed discovery of a second population at Hilaan Point, Dededo,
totaling approximately 100 individuals or less. Besides the new
population at Hilaan and the original at Haputo Ecological Reserve
Area, one peer reviewer suggested the fragile tree snail may occur in
other undiscovered locations on Guam, where access is limited and
difficult. Additionally, one peer reviewer noted that the fragile tree
snail is often confused with the Guam tree snail due to superficial
similarities, particularly juveniles of the Guam tree snail, even by
trained biologists, although DNA comparisons have helped to confirm
identifications.
Our Response: We appreciate receiving the status update for the
fragile tree snails, which we have included under Description of the 23
Mariana Islands Species, above. Additionally, we have added the
distinguishing phenotypic traits of the fragile tree snail to our files
(Fiedler 2014, in litt.).
(14) Comment: One peer reviewer commented that the Guam tree snail
is the most widespread and common partulid on Guam and its abundance is
underreported in the proposed rule. This peer reviewer stated that
surveys on Guam have documented at least 26 separate locations, varying
from quite small in size to relatively large populations (e.g., one
population contained a single tree with over 700 individuals on it).
The reviewer cautioned, however, that because a large tree may hold
hundreds of snails and the majority of any given population, the loss
of a single tree could potentially have a significant negative impact
on a population. The researcher further noted that observed
fluctuations of Guam tree snails from 100 individuals or so down to
only a few individuals within a month's time indicates that populations
are vulnerable to mass mortality, possibly from manokwari flatworms or
other factors. The reviewer concluded by stating that, although the
abundance and range of the Guam tree snail may be greater than
previously reported, the species remains threatened by a variety of
factors.
Our Response: We appreciate the new information about the range and
abundance of the Guam tree snail, and we have revised the description
of the status of the species under the Description of the 23 Mariana
Islands Species, above. We considered whether this information might
change our evaluation of the status of the species. As part of our
evaluation, we also carefully weighed the new information regarding the
significant threat posed to all of the tree snails by the predatory
manokwari flatworm, which we had underestimated in our proposed rule
(see our response to Comment 25, below). We considered the fact that
the Guam tree snail is a single-island endemic, and in addition to
being subject to predation by the manokwari flatworm everywhere it is
found on Guam, the Guam tree snail is subject to a significant number
of other threats as well. Thus we concluded that, despite having a
wider range and greater abundance than described in our proposed rule,
the Guam tree snail currently remains at great risk of extinction due
to a variety of factors including habitat loss, predation by flatworms
and other nonnative mollusks, and a lack of genetic diversity.
(15) Comment: One peer reviewer provided updated information
regarding the status of the humped tree snail and noted that there are
now two known populations of the species on Guam, both of which are
located at HERA. The peer reviewer also recommended efforts to conserve
all populations of the species in the event that allopatric populations
between the islands turn out to be different subspecies or species.
Additionally, the reviewer noted that,
[[Page 59475]]
although a captive-breeding program in the United Kingdom (UK) has been
successful in culturing the humped tree snail (Pearce Kelly, pers.
comm.), that population originated from a single individual, apparently
collected in Saipan, and, therefore, genetic diversity in the captive
population is likely very low.
Our Response: We appreciate receiving the new information and
updated status on the humped tree snail. A recent survey conducted by
Myounghee Noh and Associates (2014, pp. 1-28 and Appendices A and B)
also reported this newly discovered second population of the species at
HERA. We have added this new information under Description of the 23
Mariana Islands Species, above. At the time of the publication of the
proposed rule, we were aware of only the one population with 50
scattered individuals along the forest edge adjacent to the sand at
HERA.
As discussed in this final rule, we understand that genetic work is
ongoing on humped tree snail populations to elucidate any possible
further divisions of the species into separate subspecies or
subspecies. We agree there is a need for further research in this area.
We must make our determination based on the best scientific data
available, and at this point in time the humped tree snail is
recognized as a single species. Our determination is that the humped
tree snail, as currently described, warrants listing as an endangered
species. If taxonomic changes are made in the future, we may reevaluate
the status of any newly recognized species or subspecies at that point
in time.
(16) Comment: One peer reviewer stated there may be a few native
predators on Guam's partulids, particularly crustaceans (e.g., anomuran
crabs (land hermit crabs, coconut crabs), as well as the `arboreal
crab' (Labuanium rotundatum)); however, crabs are not regarded as a
major threat to partulids compared to the manokwari flatworm. This peer
reviewer also commented that mites in the genus Riccardoella have been
found on the native marsh snail and on another terrestrial snail,
Pythia scarabaeus. Mites in the genus Riccardoella are known parasites
of terrestrial snails and slugs; and until now have not been recorded
from the Mariana Islands.
Our Response: We have added native crabs and nonnative parasitic
mites as potential threats to partulids in our threats analysis.
(17) Comment: Based upon observations of ants inside of shells from
recently dead tree snails still stuck to vegetation and, while
inspecting live partulids, one peer reviewer expressed concern
regarding the potential for ants to prey upon partulids in the
Marianas, particularly by the little fire ant (Wasmannia auropuncta)
due to its aggressive nature.
Our Response: We have added predation by ants as a potential threat
to the partulid tree snails in the Marianas.
(18) Comment: One peer reviewer commented that the negative impact
of ungulates on partulid populations cannot be overstated and noted
that the presence of pigs and deer in large numbers ensures that the
understory of the vegetation will be trampled or devoured, altering the
presence of snail home plants and degrading the soil. The reviewer
noted repeated observations of locations that once had thriving tree
snail populations being turned into ``snail-free zones'' due to the
impact from pigs and deer.
Our Response: We agree that both pigs and deer alter and
significantly impact the habitat that supports the four tree snails;
this threat is identified as one of the many factors that have led to
the listing of these four species as endangered in this final rule (see
Factor A. The Present or Threatened Destruction, Modification, or
Curtailment of Its Habitat or Range).
(19) Comment: One peer reviewer noted that, although tree snails in
the Mariana Islands likely evolved to live upon native vegetation,
there are no clear indications of obligate relationships with any
particular type of tree or plant. This commenter further noted that all
three partulid snail species on Guam (humped tree snail, Guam tree
snail, and the fragile tree snail) are observed to use nonnative ``home
plants'' to which they have apparently adapted. The peer reviewer
suggested that an ecosystem approach may pose some challenges for
conservation of the snails given their adaptation to nonnative
vegetation, and recommended that snail conservation actions ensure the
safety of native partulids inhabiting nonnative vegetation prior to
removal or control of that vegetation.
Our Response: We are aware that some partulid snail populations in
the Mariana Islands occur on nonnative plants. For example, Service
biologists have observed tree snails in Rota on nonnative plant species
such as Triphasia trifolia, which is widely recognized to have negative
impacts on native forest structure (Harrington et al. 2012, in litt.,
p. 44; CABI 2014-Invasive Species Compendium Online Database).
Nevertheless, we appreciate the peer reviewer highlighting this
nonnative plant management concern, and we agree this issue may present
a management challenge in the future when we address the species'
recovery. Most research, however, indicates the four proposed partulid
snail species prefer native plant species as home plants or trees (see
Description of the 23 Mariana Islands Species, above).
(20) Comment: One peer reviewer stated that tree snails on Guam
tend to occur in proximity to sources of fresh water and high humidity,
and noted that these conditions are also ideal for the predatory
manokwari flatworm, which has been observed at nearly every location
where partulid snails occur on Guam.
Our Response: We appreciate the information emphasizing the overlap
between habitat preferences of tree snails and the distribution of the
manokwari flatworm on Guam. Based on the comments of peer reviewers and
new information available to us since the publication of the proposed
rule (for example, high reproductive capacity of the flatworm and
significant rates of tree snail mortality when the flatworm is
present), we conclude that the threat posed by the manokwari flatworm
is considerably greater than we had formerly understood. We have
incorporated this new information into this final rule, and it is our
intent to identify this threat as both a research need and management
concern during future conservation and recovery efforts for the
partulid snails.
(21) Comment: One peer reviewer cautioned against a narrow focus of
conservation effort for the Guam tree snail given its widespread
distribution. The reviewer suggested that protecting only the Guam tree
snail populations in HERA and Hilaan, due to its abundance and co-
occurrence with the fragile tree snail and the humped tree snail, risks
losing important biodiversity from other population sites.
Our Response: We appreciate receiving this perspective from the
peer reviewer. The prioritization of conservation and recovery actions
for the tree snails and other species listed in this final rule will be
identified and addressed in a forthcoming recovery plan.
(22) Comment: Two peer reviewers provided new information and
updates regarding the distribution of the humped tree snail based on
recent surveys for the species. The reviewers noted that while once
widespread on Guam, humped tree snails are now restricted to small
populations at only 2 or 3 sites on Guam; a single remnant population
on Saipan in one small area; one population of 1,000 individuals on
Pagan Island in a small area within the
[[Page 59476]]
ancient southern caldera; one population of unknown size on the summit
of Sarigan; and one small, isolated population discovered in 2013 on
Tinian.
Our Response: We appreciate receiving the updated distribution
status for the humped tree snail and have added any new relevant data
under Description of the 23 Mariana Islands Species, above. In
particular we appreciate learning of the recent discovery that a humped
tree snail colony still occurs on the island of Tinian, as previous
data had indicated that the species was extirpated from the island.
(23) Comment: One peer reviewer suggested that partulid snail
activity may be tied to ambient humidity and precipitation rather than
circadian pattern, as described in the proposed rule, based upon the
reviewer's observations of snails active during rainy days and snail
inactivity during dry nights. The reviewer suggested this trait may
increase the vulnerability of tree snails to changes in their
environment, should climatic conditions lead to reduced precipitation
and decreased humidity.
Our Response: We appreciate receiving this new life-history
information and included these details under Description of the 23
Mariana Islands Species, above. Additionally, we will address the
matter further as we begin the recovery planning phase for these
species.
(24) Comment: One peer reviewer questioned the purpose of citing
Crampton (as referenced in Berger et al. 2005) in the proposed rule
regarding the presence of as many as 31 partulid snails on the
underside of a single leaf of Caladium. The peer reviewer noted that,
when partulid snails were observed in large clusters on leaves, it was
always among relatively sizeable and dense, albeit rare, populations of
snails, that would have been readily observed even if some individual
leaves were not inspected.
Our Response: We included Crampton's field observations in the
proposed rule to illustrate the potential challenge in accurately
surveying for numbers of snails in nature. If a population of snails
has only 100 individuals, for example, missing a single leaf with 30 or
more snails representing up to a third of the total population would
result in a substantial underestimate of population size.
(25) Comment: Three peer reviewers commented that the level of
threat posed by the manokwari flatworm is erroneously understated in
the proposed rule, and provided additional information about its
predation efficiency and potential to impact the tree snails, including
the following observations: One reviewer noted that the manokwari
flatworm, once considered mostly ground-dwelling, is now known to climb
trees and feed on juvenile partulid snails, and during field surveys
the flatworm has been found to commonly occur several meters up in
native trees and during most rain events. The reviewers emphasized that
the flatworm is an effective predator on the tree snails of all age
classes, and is likely the most important threat to these tree snails
since it occurs in native, nonnative, and disturbed forest.
Our Response: We appreciate receiving this new information, and we
have updated the discussion of this threat under the Summary of
Biological Status and Threats Affecting the 23 Mariana Islands Species.
Additional new information we considered in evaluating the threat posed
by the manokwari flatworm includes the high fecundity of the flatworm,
which can reach the age of sexual reproduction in just 3 weeks, and can
lay cocoons at 7- to 10-day intervals, producing a mean of 5.2
juveniles from each cocoon (Kaneda et al. 1990, p. 526). The manokwari
flatworm can live up to 2 years and survive extended periods of
starvation, retaining their reproductive capacity after more than a
year without feeding (Kaneda et al. 1990, p. 526). Compared to the
partulid tree snails, which generally start reproducing at about 1 year
of age and produce up to 18 young a year (living up to 5 years), it is
clear that the flatworm can quickly outnumber native tree snail
species. This fact, combined with the observed high potential rates of
predation by the flatworm under field test conditions (up to 90 percent
mortality of tree snails within 11 days (Sugiura et al. 2006, p. 72)),
and its rapid, unintentional introduction to new geographic areas,
leads us to agree with the peer reviewers that we formerly
underestimated the degree of threat posed by the manokwari flatworm.
(26) Comment: One peer reviewer commented that investigations on
Rota in 1990, and Saipan, Sarigan, and Pagan in 2010, indicate that
none of the native Partula species are abundant or secure on any of
those islands visited with the exception of Sarigan, on which only a
single species, the humped tree snail, is present. With only Sarigan
containing a vigorous population of the humped tree snail, the reviewer
stated that this species most certainly has declined throughout a
significant portion of its range, and pointed out that the humped tree
snail is not secure even on Sarigan, as this island is not safe from
other threats including new or existing invasive species, volcanic
activity, etc. Another peer reviewer also commented that, despite the
encouraging occurrence of seemingly large, healthy populations of
humped tree snail on Sarigan, human access remains unrestricted on that
island, and species such as rats, ants, or other snail predators may
gain access to the island through unregulated human landings, resulting
in invasive predators that are virtually impossible to control.
Our Response: We have updated our records as appropriate regarding
the field observations and data collected on partulids in the Marianas
and incorporated this new information into this final rule. Although
the proposed rule had noted that rats and monitor lizards are already
present on Sarigan, we have noted the threat of additional potential
predators to the island's population of the humped tree snail (e.g.,
potential invasion by the manokwari flatworm, if it is not already
present). We are aware that humans occasionally access the more remote
northern islands and the associated risk of newly introduced nonnative
species. We agree with the reviewers that the humped tree snail remains
threatened by a variety of factors throughout its range, including on
the island of Sarigan.
Peer Review Comments on Slevin's Skink
(27) Comment: One peer reviewer concurred with our assessment of
the status and threats to Slevin's skink, but noted that we had failed
to note extirpated populations for Slevin's skink species in Table 1 of
the proposed rule, as we had done for other species. The reviewer
indicated that Slevin's skink was formerly present but is no longer
found on Guam, Rota, and Tinian. The reviewer furthermore noted that,
since Slevin's skink was not found on Pagan during the recent intensive
surveys there (Reed et al. 2010), it is most likely also extirpated, or
at least certainly rare, on Pagan as well. Lastly, the reviewer
suggested there may be an unverified record for Slevin's skink on Maug
at this time.
Our Response: We appreciate the information and have corrected
historical occurrences of Slevin's skink in Table 1, and noted the
possibility of Slevin's skink being extirpated on Pagan under
Description of the 23 Mariana Islands Species. We have added the
possible occurrence of Slevin's skink on Maug to our files, but did not
include this information here since this record is unverified at this
time.
[[Page 59477]]
(28) Comment: One peer reviewer stated that female Slevin's skinks
do not carry their eggs internally and give birth to live young
(viviparity), but rather they lay eggs in which the embryonic
development occurs outside the mother (oviparity), with a normal clutch
size of two (Zug 2013).
Our Response: We appreciate this new information and have included
it in this final rule.
Peer Review Comments on the Pacific Sheath-Tailed Bat
(29) Comment: One peer reviewer noted that recently published
scientific articles improve known biological information about the
Pacific sheath-tailed bat, and the reviewer suggested the proposed rule
be updated to reflect this new information. Additionally, the
researcher recommended that the proposed rule clarify several matters
about the bat's biology, including for example, diet, occurrence,
foraging activity, limiting factors on the island of Aguiguan, improved
understanding of the threats to the species, and the species' forest
habitat foraging requirements.
Our Response: We appreciate the comment and have included all new
relevant information reflected in the recent publications regarding the
Pacific sheath-tailed bat (see Description of the 23 Mariana Islands
Species, above).
Comments From the Government of Guam
(30) Comment: The Bureau of Statistics and Plans, Guam Coastal
Management Program (BSP-GCMP), commented that they concur with our
assessment regarding the status of the 23 species. Additionally, the
Bureau stressed the importance of effectively managing and protecting
Guam's unique natural resources from invasive species.
Our Response: We appreciate the BSP-GCMP's commitment to
conservation on Guam, and we look forward to collaborating in the
future to conserve endangered and threatened species, and their
habitats, in the Mariana Islands.
(31) Comment: The Department of Agriculture's Division of Aquatic
and Wildlife Resources (GDAWR) commented that it concurs with our
conclusions regarding the status of the 23 species. The Department
noted that the accidental introduction of the brown treesnake had
resulted in the demise of Guam's native forest birds, as well as
negative impacts to native bat and lizard populations. The Department
suggested that a loss of pollinators and seed dispersers from Guam's
ecosystems has compounded impacts upon native forest regeneration, with
cascading effects.
Our Response: We agree with the GDAWR and have evaluated the
effects of the brown treesnake on the 23 species in terms of both
direct and indirect effects, including the indirect impact of the brown
treesnake on the forest ecosystem through direct removal of animals
that act as pollinators and seed dispersal agents through predation. We
appreciate the GDAWR's comments and commitment to conservation on Guam,
and look forward to future collaboration to conserve endangered and
threatened species and their habitats on Guam and in the Mariana
Islands.
(32) Comment: The GDAWR noted that, while nine of Guam's native
bird species and two fruit bat species were listed under the ESA due to
the threat of extinction from the brown treesnake, the department had
initiated recovery actions to save Guam's endemic bird species by
collecting the remaining individuals from the wild and implementing
ongoing active captive-breeding and release programs. The GDAWR
comments that its vision remains to return these listed species, as
well as those unlisted species that remain in the CNMI, to the forests
on Guam through the control of brown treesnake and other predators that
impact the restoration of the species.
Our Response: We commend the GDAWR for its vision and efforts to
conserve Guam's endangered species and other native biota. As discussed
in this final rule, the brown treesnake continues to pose a significant
threat to the native species of Guam, through both direct effects, such
as predation, and by indirect effects, including altering forest
structure by interfering with natural seed dispersal mechanisms.
Gaining control of the brown treesnake and other nonnative predators
will directly or indirectly benefit all 23 species in this final rule,
as well as previously listed species in the Mariana Islands.
(33) Comment: The GDAWR noted that increasing development on
military and private lands continues to directly threaten native
species, including the partulid snails, through loss of habitat.
Our Response: We appreciate the GDAWR's comments and commitment to
conservation on Guam, and concurrence regarding the threat posed to
Guam's native species, including the partulid snails, by habitat loss
due to increasing development on military and private lands.
(34) Comment: The GDAWR noted that isolated pockets of native
snails are being discovered through surveys conducted to assess their
status on Guam. They also suggested that these species are recoverable
through mitigation measures and transplantation to areas where feral
pigs and introduced deer are controlled, despite the threat of
predation by the flatworm and predatory nonnative snails.
Our Response: We agree that several attributes of the partulid
snails, including their size and transportability, increases the
likelihood of their eventual conservation and recovery. Specific
recovery actions for the tree snails and other species listed here will
be identified and addressed in the recovery planning process,
subsequent to this rulemaking.
(35) Comment: The GDAWR commented on the importance of conserving
unique native plant species, including fadang (Cycas micronesica), an
endemic species that was once dominant in the limestone forests on
Guam. They concurred with our assessment that fadang has been hit hard
by introduced pests (most notably, the cycad scale) that limit its
growth and reproduction. The GDAWR expressed support for the listing of
this species, which will in turn provide for the recovery of other
native species that depend on native forest.
Our Response: We appreciate the agreement with our assessment of
the status of Cycas micronesica and the threats to that species, as
well as other native plant species of the Mariana Islands. We look
forward to continuing our collaboration with GDAWR to protect
endangered and threatened species, and their habitats, in Guam and the
CNMI.
Comments From the CNMI Government
(36) Comment: The CNMI Department of Land and Natural Resources
(DLNR) concurred with our assessment of the status of 7 of the 23
species in the proposed rule (three plants: Cycas micronesica,
Heritiera longipetiolata, and Tabernaemontana rotensis; and four
animals: Pacific sheath-tailed bat, humped tree snail, Langford's tree
snail, and the fragile tree snail), and our conclusion that these 7
species meet the definition of threatened or endangered under the Act.
For the remaining nine species in this final rule that occur in the
CNMI, they did not agree with our assessment of the status of six plant
species, including the four orchids (Bulbophyllum guamense, Dendrobium
guamense, Nervilia jacksoniae, and Tuberolabium guamense), Maesa
walkeri, or Solanum guamense, which are addressed in comment (44) .
They expressed skepticism regarding the presence of the Mariana eight-
spot butterfly on Saipan (see comment (37));
[[Page 59478]]
and they did not express a clear position regarding the proposed
listing of the Rota blue damselfly (see comment (38)) or Slevin's skink
(see comment (39)).
Our Response: We appreciate the CNMI DLNR's agreement with our
assessment of the conservation status of 7 of the 23 species addressed
in this final rule. Comments from the CNMI DLNR relevant to the other
CNMI species considered in this final rule are addressed separately in
response to the comments noted above.
(37) Comment: The CNMI DLNR commented that they are unable to
verify the claim in the proposed rule that the Mariana eight-spot
butterfly once occurred on Saipan, and the modern range does not appear
to include the CNMI. The proposed rule cites two unpublished reports
(Schreiner and Nafus 1996, Schreiner and Nafus 1997); however, neither
of these reports cite a source for the occurrence on Saipan. In
addition, the 1996 paper states ``no specimens were found in the fairly
extensive collection of butterflies at the Saipan Department of
Agriculture.'' The DLNR suggests that, despite recent targeted surveys,
there is no verifiable evidence that the Mariana eight-spot butterfly
has been found on Saipan within at least the last 40 years; therefore,
Saipan should not be considered within the range of the Mariana eight-
spot butterfly.
Our Response: The proposed rule described Saipan as part of the
historical range of the Mariana eight-spot butterfly, and noted that it
may possibly be extirpated from that island; only Guam was included
within the description of the known contemporary range of the species.
To clarify where the data regarding the historical occurrence of the
Mariana eight-spot butterfly on Saipan originates, there is a
placeholder and label at the Bishop Museum for a Mariana eight-spot
butterfly specimen collected on Saipan on July 30, 1920, which was
loaned to the American Museum of Natural History (AMNH) (Richardson
2015, in litt.). The new collection manager at the Bishop Museum has
requested information from AMNH regarding this specimen. If this
specimen is in error, the known range for the Mariana eight-spot
butterfly will be edited to solely include Guam; however, at this time,
evidence suggests that the historical range of this species includes
Guam and Saipan (Richards 2015, in litt.). At least one species expert
suggests that the Mariana eight-spot butterfly and Mariana wandering
butterfly may persist on some of the northern Mariana Islands in very
low numbers, making observations difficult (Rubinoff 2014, in litt.).
Butterfly experts continue to search islands not previously known to
support either of the two butterflies addressed in this rule.
(38) Comment: The CNMI DLNR stated that the Rota blue damselfly
appears to be associated with an uncommon specialized habitat on Rota,
i.e., freshwater streams at relatively high elevation. Additionally,
they report a new occurrence of the Rota blue damselfly, located at a
stream east of the Water Cave that is not connected to the Water Cave
(Okgok) Stream (Zarones et al.2015b, in litt.). A comprehensive survey
of all potential habitat sites on Rota has not been conducted, and no
surveys of potential habitat on Saipan have been conducted.
Our Response: We have added the stream east of the Water Cave as a
new population site for the Rota blue damselfly under Description of
the 23 Mariana Islands Species, above; and to Summary of Changes from
the Proposed Rule, above. We note, however, that this observation was
of a single individual. In addition, we concur that comprehensive
surveys of all potential habitat have not been conducted on Rota and
Saipan. The Service looks forward to collaborating with the CNMI DLNR
to collect more data on this species and monitor known populations.
(39) Comment: The CNMI DLNR stated that the status and trends of
the Slevin's skink are unknown in the northern Mariana Islands The DLNR
assumes that the Slevin's skink persists on Guguan and Asuncion, in
addition to the occurrences on Alamagan and Sarigan described in the
proposed rule. The DLNR's Division of Fish and Wildlife will be
conducting expeditions to Guguan in 2015 and 2016, which should permit
confirmation of its persistence there, as well as provide information
on the status of potential invasive predators.
Our Response: The skink was historically known from Guam, Cocos
Island, Rota, Tinian, Pagan, Sarigan, Guguan, Alamagan, and Asuncion;
however, it is believed to be extirpated from Guam, Rota, Aguiguan, and
Tinian, and was not observed during a recent survey on Pagan (Reed et
al. 2010, pp. 22, 27) (see Description of the 23 Mariana Islands
Species, above). We concur that the status of Slevin's skink is unknown
on several of the northern islands (e.g., Sarigan, Guguan, Alamagan,
and Asuncion); however, the skink is thought to be extirpated on four,
now possibly five, of the nine islands on which it was previously known
to occur. Of the islands where it is known to persist, Slevin's skink
has begun to recover from the effects of past threats (ungulates, which
were removed) only on Sarigan, and even there it still faces other
threats (e.g., rats). It appears to be very rare on the other small
islands where it remains, and may be extirpated from Pagan. The greatly
reduced distribution of this species, now restricted to roughly 10
percent of its former range, combined with the risk from rat predation
on all of the northern islands on which it occurs; predation by monitor
lizards on Sarigan, Alamagan, and Pagan; habitat degradation by feral
pigs and goats on Alamagan and Pagan; and habitat destruction from
proposed military actions on Pagan leads us to conclude that Slevin's
skink warrants the protections of the Act. We look forward to learning
the results from the planned surveys, and to collaborating with the
CNMI DLNR to learn more about the status of Slevin's skink in the
northern islands.
(40) Comment: The CNMI DLNR stated that Heritiera longipetiolata
still occurs on Rota, contrary to the information presented in the
proposed rule. They provided information that a field biologist
observed one large individual of Heritiera longipetiolata on the Rota
Sabana in 2010. Additionally, the Rota DLNR is currently propagating
and outplanting Heritiera longipetiolata (Manglona, pers. comm. 2014).
Our Response: We have added the new location data for Heritiera
longipetiolata, on Rota under Islands in the Mariana Archipelago,
Description of the 23 Mariana Islands Species and Table 4, above; and
under Summary of Changes from the Proposed Rule, above.
(41) Comment: The CNMI DLNR stated that the information presented
in the proposed rule regarding the number of individuals of Heritiera
longipetiolata on Saipan and Tinian is confusing. The DLNR urged the
Service to contact local botanical experts directly for information,
and provided the original reference for an occurrence on Saipan
(Camacho and MES 2002, pp. 38-39). This report includes 53 individual
Heritiera longipetiolata trees, of which 37 were with flower or bud, as
well as 383 seedlings beneath the adult trees (Camacho and MES 2002,
pp. 38-39).
Our Response: We appreciate the clarification regarding the number
of individuals of Heritiera longipetiolata on Saipan. We have added the
53 individuals and numerous seedlings of Heritiera longipetiolata
observed by Camacho and MES (2002, pp. 38-39) under Description of the
23 Mariana Islands Species, above. The 30 Heritiera longipetiolata
individuals on Saipan referenced in the proposed rule
[[Page 59479]]
originated from an estimate we made using the best available data we
had at the time (Guerrero 2013, in litt.; Williams 2013, in litt.;
Wiles in IUCN Red List 2014, in litt.). Regarding the number of
individuals on Tinian, new information has revealed that there are at
minimum 30 to 40 individuals of Heritiera longipetiolata in the
southeast portion of Tinian, and likely more individuals in the area
along the forested eastern portion of Tinian (Spaulding 2015, in
litt.). We have corrected the estimated number of individuals for
Heritiera longipetiolata on Tinian under Description of the 23 Mariana
Islands Species, above. The Service has been in contact with local
biologists, including those from the CNMI DLNR, since 2012 in
preparation of the development of this rule (Harrington et al.2012, in
litt.) (please see our response to comment (73), below).
(42) Comment: The CNMI DLNR recommends that surveys be conducted in
the near future to determine the current status of the occurrences of
Heritiera longipetiolata that have been recently reported on Saipan,
Tinian, and Rota, and asked that we contact the State Forester directly
to discuss the status and occurrences of this species in the CNMI.
Our Response: We agree that further surveys need to be conducted to
better understand the number and status of individuals of Heritiera
longipetiolata on the islands of Saipan, Rota, and Tinian in the CNMI.
We attempted to contact the State Forester directly as suggested on
April 22, 2015, to discuss the status of this species in the CNMI, but
to date have not received a response. Although we acknowledge that more
information is always desirable, the Act requires that we make our
decisions based on the best scientific and commercial data available at
the time of our determination.
(43) Comment: The CNMI DLNR requested that the Service provide the
reference for the eight individuals of Tabernaemontana rotensis on Rota
in 2004, and whether or not these individuals were naturally occurring
or outplanted since the proposed rule does not consider outplanted
individuals as an occurrence. The proposed rule states ``Currently on
Rota, T. rotensis is known from two occurrences, each composed of fewer
than 5 individuals'' and cites Harrington et al.(2012); however,
Harrington et al. (2012) does not provide the exact numbers, only ``low
number of individuals.'' This reference does state the two locations of
the occurrences where this species was observed (Palii and Water Cave).
In 2014, DLNR completed a survey of all known locations of naturally
occurring and outplanted individuals of T. rotensis on Rota and found
nine living naturally occurring individuals and one dead individual.
Additionally, they report 30 surviving outplanted individuals, ranging
in size from 4 to 23 ft (1.3 to 7 m), spread out across the island (J.
Manglona, T. Reyes, R. Ulloa, pers. comm. 2014). The Rota DLNR Forestry
Division has been carrying out an outplanting program for
Tabernaemontana rotensis for several years.
Our Response: It is correct that the Service does not count
outplanted individuals in our analyses regarding the number of
individuals and occurrences for plant species. We appreciate the update
regarding the number of T. rotensis individuals on Rota, and have added
this updated information under Description of the 23 Mariana Islands
Species, above, in addition to correcting the language to reflect
precisely the wording in the cited report regarding low numbers of
individuals.
(44) Comment: The CNMI DLNR and a representative of the CNMI
legislature stated that the proposed listing for many of the 23 species
was based on their status and threats on Guam with little consideration
to their status and threats in the CNMI, and that the proposed rule
provided inadequate information to support the determination of
endangered status for several of the 23 species. Species specifically
mentioned include all four orchid species (Bulbophyllum guamense,
Dendrobium guamense, Nervilia jacksoniae, and Tuberolabium guamense),
the shrub to small tree Maesa walkeri, and the herbaceous plant Solanum
guamense. Their comments include the following: There is no evidence to
indicate a decline of Bulbophyllum guamense, Dendrobium guamense,
Nervilia jacksoniae, Tuberolabium guamense, or Maesa walkeri on Rota,
and these species are much more common in the CNMI than indicated in
the proposed rule. They provided the results of a 7-day survey by DLNR
biologists (conducted in 2015) with both observed numbers and, by
extrapolation, estimated counts for each of these species on Rota.
Based on their observations, DLNR biologists estimated the total number
of individuals on the western portion of Rota to be approximately
16,000 for Bulbophyllum guamense, approximately 35,000 for Dendrobium
guamense, approximately 100,000 for Nervilia jacksoniae, and
approximately 14,600 for Tuberolabium guamense. For Maesa walkeri, they
were unable to calculate the density and, therefore, make an estimate
for the Sabana region, but the DLNR stated they are confident that
thousands of Maesa walkeri exist on the Sabana plateau, and perhaps
other locations on Rota. They could not say at this time whether or not
Maesa walkeri is restricted to the Sabana Region.
Our Response: The Service evaluates a species for potential listing
under the Act based on the status of that species throughout all or a
significant portion of its range at the time of the determination. For
some of the 23 Mariana Islands species, that range is represented by a
single island (e.g., Eugenia bryanii and Langford's tree snail), while
other species have ranges that include two or more islands (e.g.,
Bulbophyllum guamense and the humped tree snail) (see Description of
the 23 Mariana Islands Species and Table 1, above, for the range of
each of the 23 species). In each case our evaluation includes
consideration of the status of these species and threats acting upon
them throughout the entirety of their present ranges, which for each of
the four orchids and Maesa walkeri, predominantly includes the islands
of Guam and, in the CNMI, Rota. The DLNR provided new information from
surveys conducted since the publication of the proposed rule
demonstrating that these five plant species are more numerous on the
island of Rota than previous data indicated, each with a population
structure consisting of seedlings, juveniles, and adults. We have
incorporated this new data into our consideration of the status of
these species, and conclude that this information indicates these five
plant species are not as imperiled throughout their ranges as we had
understood at the time of the proposed rule. However, these species are
still susceptible to multiple threats, including habitat destruction
and modification by nonnative plants and animals, the potential effects
of climate change, and fire on Rota. Additionally, at least 50 percent
of their respective ranges occur on the island of Guam, where these
species once occurred in abundance but now exist in very low number of
individuals and face similar threats as on Rota, in addition to habitat
destruction and modification by urban development, military development
and training, brown treesnakes, and feral pigs.
The Act defines an endangered species as ``any species which is in
danger of extinction throughout all or a significant portion of its
range,'' and a threatened species as ``any species which is likely to
become an
[[Page 59480]]
endangered species within the foreseeable future throughout all or a
significant portion of its range.'' Therefore, because the four orchid
species (Bulbophyllum guamense, Dendrobium guamense, Nervilia
jacksoniae, Tuberolabium guamense) and Maesa walkeri appear relatively
healthy on Rota, but are threatened by the above-mentioned factors
throughout all of their ranges, and have declined across at least 50
percent of their ranges (i.e., on Guam), we have retained them in this
final listing determination but have changed their status to threatened
species, as we conclude they are at risk of becoming endangered within
the foreseeable future. All new data received during the comment period
for these five species have been added to Description of the 23 Mariana
Islands Species and Summary of Biological Status and Threats Affecting
the 23 Mariana Islands Species, below. Further, our rationale for
listing each of these five species as threatened species versus
endangered species is discussed under Determination, below.
(45) Comment: The CNMI DLNR commented that the Service used
inaccurate scientific methods to determine the status of the 23 species
and the proposed rule contains several inaccuracies regarding sources
of citations and misleading use of references. Specifically, they
stated that the Service should have conducted comprehensive surveys
across all 14 islands of the CNMI in order to determine the status of
the respective species reported to occur historically or currently in
the CNMI. Furthermore, they felt the Service relied upon a broad range
of factors purported as causing declines with little to no direct
scientific evidence that these factors are negatively affecting each
species (i.e., inadequate regulatory mechanisms, typhoons, and climate
change).
Our Response: We agree that conducting comprehensive surveys across
all 14 islands within the CNMI would be ideal; however, this is not
practical or possible. As required by the Act, we have relied upon the
best scientific and commercial data available to inform our evaluation
and decision. For example, the references cited show that the threats
outlined in the proposed rule, and this final rule, negatively affect
one or more species, their habitat(s), or both (see Summary of
Biological Status and Threats Affecting the 23 Mariana Islands Species,
above). In our analysis, we thoroughly considered whether these
threats, acting either singly or in concert, are affecting each of
these species to the degree that the species meets the definition of an
endangered species or threatened species under the Act. We affirm our
position that threats associated with climate change, inadequate
regulatory mechanisms, and typhoons are well supported, as detailed and
referenced in this document. Each of these stressors may not
necessarily act as a direct threat to the species, but may be
considered a contributing factor to endangered or threatened status
when evaluated in conjunction with other stressors acting on the
species. As described in this final rule, considered collectively, our
evaluation leads us to the conclusion that the negative effects of all
these threats on these species, which are already vulnerable due to
restricted ranges and reduced population sizes and numbers, are such
that they meet the definition of an endangered species or threatened
species under the Act. Further, minor corrections and changes to the
citations are noted under Summary of Comments and Recommendations,
herein, or have been directly incorporated into this final rule. More
substantial corrections and changes are noted under Summary of Changes
from the Proposed Rule, above.
(46) Comment: The CNMI DLNR commented that the Service used
arbitrary definitions of the term ``decline.'' The use of decline
should be consistent and use actual numbers of individuals rather than
a decline in overall range (i.e., a decline in the number of islands on
which a species occurs).
Our Response: We believe this may be a matter of semantics. In the
proposed rule, we used the word ``decline'' as a synonym for
``reduction'' or ``loss.'' We recognize that some readers may prefer
the term ``decline'' to be used in association with specific
quantitative data, as in numbers of individuals, whereas the term
``reduction'' may be considered more appropriately used with regard to
more general qualities, such as the range of the species. However,
whether called a decline or a reduction, a significant loss of a
species from its former range is widely recognized throughout the
conservation literature as a threat because it reduces the redundancy
and resiliency of that species to withstand future perturbations. It
may also result in a significant loss of evolutionary or adaptive
capacity, through a loss of genetic diversity. For example, the range
of the Mariana subspecies of the Pacific sheath-tailed bat has either
declined or been reduced from possibly seven islands to only one,
Aguiguan. The fact that the range of this subspecies has now been
diminished such that it now exists in a single known population on only
one island renders it vulnerable to extinction, regardless of the
metric used to describe that loss of range. In addition, it is
reasonable to conclude that a species that has experienced a
significant reduction in range has also been reduced in abundance.
(47) Comment: The CNMI DLNR and one public commenter stated that
the proposed rule contains unreasonable assumptions (i.e., threats,
impacts to species, and invasive species), is based on little to no
empirical data, and that both the ecosystem approach and climate change
sections are oversimplified. The ESA lists species, not ecosystems, and
is a species-based regulation. As such, the factors must be considered
as they individually affect species, whether directly or indirectly.
Our Response: The proposed rule describes the known negative
impacts of nonnative animals and plants, the projected effects of
climate change, and other threats as reported in the peer-reviewed
scientific conservation literature. The negative impacts on species and
on ecosystems resulting from the introduction of nonnative species are
well documented around the globe (Vitousek et al. 1997, pp. 1-16;
Reaser et al. 2007, pp. 98-111; Pimentel 2011, pp. 1-7; Simberloff
2011, in litt.; Simberloff et al. 2013, pp. 58-60). Additionally,
climate change impacts at the ecosystem and species level are
documented around the globe and include, but are not limited to,
alteration in humidity, temperature, and sea level, which subsequently
result in species range shifts, alterations of a specific microhabitat
upon which select species depend, or disruption in pollination regimes
(e.g., disruption in pollinator life cycle or flowering life cycle of a
plant to where they are no longer in sync to promote pollination) (Chen
et al. 2011, pp. 1,024-1,026; Saikkonen et al. 2012, pp. 239; Robbirt
et al. 2014, pp. 2,845-2,849; Willmer 2014, pp. R1133-R1135; Lambers
2015, pp. 501-502; Urban 2015, pp. 1-33). Although we may not have
empirical data that definitively demonstrates or quantifies the effect
of these threat factors specific to each species considered in this
final rule, if those threat factors are present, it is reasonable to
conclude that they would have the same negative impact on any of the 23
Mariana Islands species that has been observed in other situations and
reported in the literature. We have attempted to clarify here that
although the specific future effects of climate change cannot be
determined at this point, the anticipated changes in environmental
conditions as a result of climate change are likely to further
exacerbate the existing threats to the 23
[[Page 59481]]
species. As required by the Act, we must make our determinations based
on the best scientific and commercial data available. Lacking
observations of how each of the 23 Mariana Islands species may
specifically respond to the threat factors considered here, we must
rely upon reasonable assumptions regarding the effects of those threats
as informed by the best available science.
We agree that the ESA lists species, not ecosystems, and this is a
species-based regulation. Under the Act, we determine whether a species
is an endangered species or a threatened species based on any of five
factors (see Summary of Biological Status and Threats Affecting the 23
Mariana Islands Species, above), and we are required to make listing
determinations solely on the basis of the best available scientific and
commercial data available [emphasis ours] (sections 4(a)(1) and
4(b)(1)(A) of the Act). As described in this final rule, we have
thoroughly considered the best scientific and commercial data available
for each of the species under consideration, and have made our
determination as to status for each species individually. It is a fact
that by virtue of occurring in the same ecosystem, many of these
species experience the same threat factors. These species are organized
by ecosystem in our proposed and final rules solely for the purpose of
considering threats that are shared by all species that occur in those
ecosystems; this avoids redundancy in the rule, as well as recognizes
that for the purposes of potential subsequent recovery actions, should
the species be listed, management to reduce those threats would
collectively benefit all species that occur in that ecosystem. This
``ecosystem'' approach to recovery is consistent with the stated
purpose of the Act under section 2(b), which states that the Act is
``to provide a means whereby the ecosystems upon which endangered
species and threatened species depend may be conserved.'' Nonetheless,
as clearly stated in this rulemaking, our evaluation and determination
regarding the status of each species is made on a case-by-case basis,
and each species is added individually to Sec. Sec. 17.11 and 17.12 of
the Code of Federal Regulations; ecosystems are not a valid subject for
listing under the Act (see Regulation Promulgation, below).
(48) Comment: The CNMI DLNR commented that at present there are
insufficient data to determine whether or not Solanum guamense meets
the criteria for listing in the CNMI. The reported occurrences for S.
guamense on six of the CNMI islands are derived strictly from herbarium
records and plant species incidental observation lists. No
comprehensive quantitative surveys have been conducted for S. guamense
anywhere in the CNMI. Without any recent systematic botanical surveys
to prove otherwise, DLNR assumes S. guamense persists on all six
islands of the CNMI where it was previously reported. They report a
plan to search for S. guamense on a 2015 Department expedition to
Guguan, and on other northern islands whenever the opportunity arises.
Our Response: We agree that additional data regarding the status of
S. guamense would be desirable. However, under the Act, we are required
to make listing determinations solely on the basis of the best
available scientific and commercial data available [emphasis ours]
(sections 4(a)(1) and 4(b)(1)(A) of the Act). Further, we consider the
status of a species throughout its entire range, regardless of
political boundaries; that is, in this case, we do not consider whether
the species warrants listing just in the CNMI, but wherever it occurs.
The best available data show that S. guamense once occurred on the
islands of Guam, Rota, Saipan, Tinian, Asuncion, Guguan, and Maug (see
Description of the 23 Mariana Islands Species, above). We have no data
available to us to suggest that it continues to be extant on any of
these islands, with the exception of Guam. Currently, the only known
occurrence of this species comes from a 1994 report on Andersen AFB on
Guam (Perlman and Wood 1994, p. 152), where a single occurrence of one
individual was observed (Perlman and Wood 1994, pp. 135-136). When the
best available scientific data indicate that a species has been reduced
to a single known individual, it meets the definition of an endangered
species under the Act.
(49) Comment: The CNMI DLNR commented that, because Solanum
guamense is reported to occur on limestone cliff and terrace habitats
on the southern islands of CNMI, and the northern islands of CNMI only
contain volcanic soils, S. guamense clearly occupies a different
habitat in the northern islands.
Our Response: Based on the best available information, the physical
nature of the substrate is more likely to be the defining factor
identifying habitat that supports S. guamense. However, we do not
disagree that it may occupy a different habitat type in the northern
islands of CNMI. Muller-Dombois and Fosberg (1998, p. 243) observed
that the forest type on rough lava flows on some of the northern
islands, especially Alamagan, is similar in aspect and even in
composition to the forest on rough limestone in the southern Marianas,
leading these researchers to suggest that the physical nature of the
substratum may be of greater importance than the chemical composition.
(50) Comment: The CNMI DLNR stated that development and
urbanization are not a threat to the four orchid species (Bulbophyllum
guamense, Dendrobium guamense, Nervilia jacksoniae, and Tuberolabium
guamense) or Maesa walkeri on Rota, and that the threat of development
and urbanization on Rota is overstated. They additionally stated that
Aguiguan is the only uninhabited southern island of CNMI, and dispute
the assertion that ecotourism development would negatively affect the
forest and cave ecosystems that support the humped tree snail,
Langford's tree snail, and the Pacific sheath-tailed bat (Marianas
subspecies). They point out that Tinian community leaders with an
interest in ecotourism have proactively initiated consultations with
DLNR Division of Fish and Wildlife staff to ensure that native species
and habitats on Aguiguan are conserved and enhanced, as they feel that
these are the foundation of a successful ecotourism enterprise.
Finally, they state that Slevin's skink occurs only on northern islands
under no threat of development.
Our Response: Although development and agriculture are not primary
threats to the four orchids or Maesa walkeri on Rota, the threat from
development exists on Guam, which consists of more than 50 percent of
their entire ranges. Additionally, we placed the proposed ecoresort on
Aguiguan, although currently uninhabited, under the general category of
development and urbanization (despite being aimed at ecotourism) since
the proposed construction on this island will remove or degrade habitat
for the Pacific sheath-tailed bat, the humped tree snail, and
Langford's tree snail. The only known population of Pacific sheath-
tailed bats occurs on Aguiguan, and any loss of habitat, including
foraging areas, will negatively impact this species. Similarly,
Aguiguan is the only island where Langford's tree snail has been
observed. The proposed military actions and associated infrastructure
on Pagan and Tinian are considered development that will negatively
impact the plant Heritiera longipetiolata, tentatively the plant Cycas
micronesica (pending identification on Pagan), the humped tree snail,
and Slevin's skink. Listing determinations are based solely on the best
available scientific and commercially available data relevant to the
status of the species; by statute we cannot consider the potential
economic
[[Page 59482]]
or political impacts when we make a determination as to whether a
species meets the definition of an endangered species or threatened
species under the Act.
(51) Comment: The CNMI DLNR stated that the scope and timing of
potential expansion of military training activities and possible
impacts on proposed species on Tinian and Pagan is speculation at this
time. The proposed rule claims that Bulbophyllum guamense was
historically on Pagan but is not currently found there, and that the
proposed military training on Pagan will negatively impact the species.
They claim this argument is flawed because if Bulbophyllum guamense has
been extirpated from Pagan, future military activities there cannot
negatively impact the species.
Our Response: The proposed actions on Tinian and Pagan, if
implemented, pose a direct threat to the species now known to occur
there: The plant Heritiera longipetiolata, the humped tree snail,
Slevin's skink, and possibly Cycas micronesica (pending confirmation on
Pagan). In addition, we note that these activities may negatively
affect the historical habitat of Bulbophyllum guamense. Although
military training and activities are not a direct threat to individuals
of B. guamense since it no longer occurs on Pagan, these activities
could negatively impact its habitat on Pagan and preclude future
recovery efforts for the species, thus affecting its conservation.
Because these actions have been officially proposed in the CNMI Joint
Military Training (JMT) draft Environmental Impact Statement (EIS)/
Overseas EIS (http://www.cnmijointmilitarytrainingeis.com/), we
conclude there is a reasonable expectation that they will be
implemented, and thus are more than just speculation.
(52) Comment: The CNMI DLNR commented that the status of the
Anatahan feral pig population is unknown following the 2003 volcanic
eruption. Feral pigs are present on Alamagan, Pagan, and Agrihan, and
could potentially threaten the humped tree snail and Slevin's skink. On
Pagan, they may threaten Cycas micronesica. Feral pigs do not co-occur
with Heritiera longipetiolata or Solanum guamense in the CNMI;
therefore, they are not a threat to these two species. Feral pigs are
noticeably absent from Rota, the only island in CNMI where 10 of the
proposed 14 plants, and the fragile tree snail, occur.
Our Response: Our own records and information, and thus this final
rule, are in agreement with DLNR's comment regarding the specific
islands in the CNMI occupied by feral pigs. However, we consider pigs a
threat to populations of both Heritiera longipetiolata and Solanum
guamense outside of the CNMI on the island of Guam, where these plant
species and pigs do co-occur (see Table 3, Table 4, and Factor A. The
Present or Threatened Destruction, Modification, or Curtailment of Its
Habitat or Range, above.
(53) Comment: The CNMI DLNR stated that water buffalo do not occur
in the CNMI.
Our Response: We agree. Our proposed rule identified water buffalo
as a potential threat only on the island of Guam.
(54) Comment: The CNMI DLNR stated that feral cattle are present
only on Alamagan and Pagan within the CNMI. Feral cattle could
potentially represent a threat to the humped tree snail and Slevin's
skink. Heritiera longipetiolata is not reported to occur on Alamagan or
Pagan, so feral cattle are not a threat to Heritiera longipetiolata in
the CNMI.
Our Response: The best available data indicate that feral cattle
occur on the islands of Alamagan and Pagan in the CNMI. Although the
proposed rule cites the presence of feral cattle also on the island of
Tinian, new information provided by the CNMI DLNR suggests that feral
cattle are no longer present on Tinian. Feral domestic cattle have
roamed Tinian for the past few centuries, which resulted in substantial
changes to the landscape by means of erosion, grazing, and trampling
(Wiles et al. 1990, pp. 167-199; NRCS 2014, in litt.). Presently,
however, the number of feral cattle on Tinian is considered negligible,
if any exist at all. Cattle ranching is on the rise on Tinian, and
cattle may become a threat on Tinian in the future. We have removed
feral cattle as a threat to species that occur on Tinian (see Summary
of Changes from the Proposed Rule, above). However, we maintain our
position that feral cattle are present on Pagan, and are a threat to
the humped tree snail, Slevin's skink, and tentatively to Cycas
micronesica.
(55) Comment: The CNMI DLNR commented that feral goats are present
on Agrihan, Pagan, Alamagan, and Aguiguan in the CNMI, and could be
considered a threat to four of the proposed animals: Pacific sheath-
tailed bat, Slevin's skink, humped tree snail, and Langford's tree
snail.
Our Response: We appreciate the confirmation regarding the threat
from goats to the species addressed in this final rule present on the
islands of Agrihan, Pagan, Alamagan, and Aguiguan. Cycas micronesica is
likely present on Pagan as well, in which case goats will also
negatively impact this species.
(56) Comment: The CNMI DLNR states that the brown treesnake is not
established on Rota, or on any other island in the CNMI and is,
therefore, not an existing threat to the species in the CNMI. Further,
interdiction of snakes from Guam continues to be addressed in the CNMI
through a robust brown treesnake program active on Rota, Saipan, and
Tinian. While it is possible that at some point in the future the brown
treesnake may become established in the CNMI, the proposed rule itself
does not consider the possibility of future establishment of invasive
species such as goats.
Our Response: We commend the brown treesnake program in the CNMI
for their dedicated work toward preventing the establishment of the
brown treesnake. We have concluded, however, that because the brown
treesnake has been found on Saipan (Campbell 2014, pers. comm.;
Phillips 2014, pers. comm.) and just recently on Rota as well (Phillips
2015, in litt.), the risk of the brown treesnake becoming established
on one or more of the islands in the CNMI is high. We disagree that the
likelihood of establishment for an invasive nonnative species such as a
goat and brown treesnake are comparable, as brown treesnake are much
smaller animals and can easily be accidentally transported in ships and
planes; thus the possibility of accidental introduction is much
greater.
(57) Comment: The CNMI DLNR states that if the brown treesnake were
to become established on Rota, it may impact the forest structure in
the very long term if seed dispersers and pollinators are eliminated.
However, the epiphytic orchids (Bulbophyllum guamense, Dendrobium
guamense, and Tuberolabium guamense) were found to occur on many
different host plants, and in the case of B. guamense and D. guamense,
they were found on several introduced plant species. Dendrobium
guamense was found on standing and fallen dead trees, and even on cliff
faces. There is no evidence to suggest an eventual change in the forest
structure would negatively impact these species.
Our Response: We disagree. The best available scientific data
indicate that if the brown treesnake were to establish on Rota, it
would impact the forest structure by eliminating seed dispersers
(Rogers 2008, in litt.; Rogers 2009, in litt.; Caves et al. 2013, pp.
1-9). The actions of the brown treesnake indirectly alter forest
structure, subsequently altering essential microclimates necessary to
support species such as the four tree snails and
[[Page 59483]]
four orchids addressed in this final rule. The three epiphytic orchids
occupy a highly specialized niche habitat that is easily disturbed.
Raulerson and Rinehart (1992, p. 89) clearly state that, although the
orchids in the Marianas appear abundant, their habitat range is
limited, and in reality these orchids are very rare. Additionally, the
brown treesnake has severely altered the forest structure on Guam
(Rogers 2008, in litt.; Rogers 2009, in litt.), where at minimum, 50
percent of the entire range exists for each of the four orchids
addressed in this final rule.
(58) Comment: The CNMI DLNR stated that the proposed rule gives
information on nine of the nonnative plant species deemed to have the
greatest negative impact on forest ecosystems, yet does not state how
precisely these nonnative plants impact the proposed species, in
particular the epiphytic orchids.
Our Response: The proposed rule and this final rule outline how
each of the nonnative plants impact native species, including the four
orchids (see ``Habitat Destruction and Modification by Nonnative
Plants,'' above). Examples provided include: Nonnative plants can form
dense blankets that smother and outcompete native plants and animals;
they can form dense tangled monostands that outcompete and crowd out
native plants or negatively alter essential microclimates that support
native animals and plants; nonnative plants can produce allelopathic
effects or be able to occupy a more broad range of habitat types thus
affording it an advantage; and nonnative plants can prevent the
establishment of native plants. Orchid-specific examples include the
potential to be smothered by nonnative vines (e.g., Antigonon leptopus)
to the degree that they do not receive sunlight or block access from
pollinators.
(59) Comment: The CNMI DLNR commented that, while fires are common
in grasslands on Rota, the species Cycas micronesica, Dendrobium
guamense, Maesa walkeri, Tabernaemontana rotensis, and the humped tree
snail are found in limestone forests, which generally are not impacted
by fire, except at the forest edge.
Our Response: Fires that occur on grasslands adjacent to the forest
edge can directly impact individuals of the noted species that occupy
the forest edge, as well as cause indirect impacts through continual
encroachment of the grassland into the forest, thus decreasing the
forested area and the habitat that supports these species. We consider
fire a threat to these species on all of the islands where they are
known to occur (see Table 3, Table 4, and Habitat Destruction and
Modification by Fire, above).
(60) Comment: The CNMI DLNR commented that they are unable to
accept typhoons as a threat for any of the proposed species. Frequent
and intense typhoons are a natural occurrence in the Mariana Islands.
These species have all persisted in the Marianas despite many typhoons
in the past. Typhoons per se are not a primary threat; however, if a
species exists in limited numbers, then a typhoon may present an
indirect threat.
Our Response: We concur that typhoons are not a threat to native
species with healthy and abundant populations, and we have modified the
discussion of typhoons in this final rule to more accurately reflect
this view. However, we do consider typhoons to pose a threat for the
very reason identified by the DLNR: Because each of the 23 species
considered here have been reduced to limited numbers and range, or are
decreasing at high rates (i.e., Cycas micronesica), they have become
vulnerable to extirpation or extinction from natural disturbances such
as typhoons. Due to the threats outlined in Table 3, these species and
their associated natural habitats now lack the natural resiliency and
redundancy they once had that enabled them to withstand such natural
events.
(61) Comment: The CNMI DLNR stated that the proposed rule claims
that individuals of Bulbophyllum guamense that occur close to the coast
in the adjacent forest ecosystem at or near sea level may be negatively
impacted by sea-level rise and coastal inundation; however, the
Department's evidence indicates the species is found only at higher
elevations, and thus would not be affected by sea-level rise.
Our Response: Although we agree that the majority of individuals of
Bulbophyllum guamense have been recorded at higher elevations, B.
guamense is also known to occur along the coastlines at the Haputo
Ecological Reserve Area, Ritidian Point, and Two-Lovers Point, on the
island of Guam, and, therefore, we conclude that sea-level rise is a
concern.
(62) Comment: The CNMI DLNR provided an update to the protected
conservation areas on both Rota and Saipan. There are three
conservation areas on Rota, including the Sabana Wildlife Conservation
Area, encompassing both the Sabana Heights and Talakhaya (added in 2007
through Rota Local Law 15-8); the Wedding Cake Wildlife Conservation
Area (Rota Local Law 9-3); and the Mariana Crow Conservation Area,
declared in 2014, which encompasses the former I-Chenchon Park (Sec.
85-30.4). On Saipan, there are six conservation areas. There are the
four areas mentioned in the proposed rule; as well as two new
conservation areas in Marpi, both deeded to DLNR in 2012, and include
the Nightingale Reed-warbler Conservation Area and the Micronesian
Megapode Conservation Area.
Our Response: We have revised this final rule to accurately reflect
this information (see Islands in the Mariana Archipelago and Summary of
Changes from the Proposed Rule, above. We support the goals and intent
of all of CNMI's natural protected areas.
(63) Comment: The CNMI DLNR commented that they acknowledge the
presence of deer on Rota, but suggested there is no evidence of deer
herbivory impacts on Cycas micronesica, Heritiera longipetiolata, or
Solanum guamense. The Department further disagreed with the claim that
mammalian herbivory by deer and pigs contributes to the decline of
Solanum guamense based upon the prevalence of Solanum torvum on Tinian,
and the fact that leaves and green fruits of plants of the Solanum
genus are often toxic to livestock.
Our Response: As noted in Table 4 of this final rule, deer are
identified as a threat on the islands of Guam and Rota. The Solanum
genus contains more than 1,500 species, many of which are edible by
animals, including S. tuberosum (potato), S. melongena (eggplant), S.
Arcanum (wild tomato), and Solanum nelsonii, endemic to Hawaii and
eaten by deer, rats, and cattle (USFWS 2014, in litt.). Furthermore,
according to our sources (Wheeler 1979, pp. 1-51; Wiles et al.1999, pp.
193-215; Perlman and Wood 1994, p. 152; Rogers 2012, in litt.; Wiles
2012, in litt.; Marler 2014, in litt.) and as reflected in Table 4, the
impacts of deer and other ungulate herbivory upon Cycas micronesica,
Heritiera longipetiolata, and Solanum guamense have been observed on
the islands of Rota or Guam, where these plants co-occur with deer and
pigs.
(64) Comment: The CNMI DLNR stated that, in consultation with
regional experts, its Division of Fish and Wildlife recently conducted
threat assessments for the Pacific sheath-tailed bat, Slevin's skink,
humped tree snail, Langford's tree snail, and the fragile tree snail.
The assessments indicated that rats have likely contributed to the past
decline in candidate snail species and remain an ongoing threat to
native snail species. However, their assessments did not identify
predation by rats or monitor lizards as a threat to the Pacific sheath-
[[Page 59484]]
tailed bat or Slevin's skink (Liske-Clark, in prep.).
Our Response: We agree with the Department that rats remain a
serious ongoing threat to the four proposed partulid snails addressed
in this rule. However, our sources regarding Slevin's slink (Losos and
Greene 1988, pp. 379-386; Rodda in litt. 1991, p. 205; Rodda in litt.
2002, pp. 2-3; Lardner in litt. 2012, pp. 1-2; Allison et al. 2013, in
litt.) and the Pacific sheath-tailed bat (Valdez et al. 2011, p. 302;
Wiles et al. 2011, p. 306;), which include several of the leading
species experts, indicate that both species are threatened by predation
from rats and monitor lizards.
(65) Comment: The CNMI DLNR stated that the proposed rule offers no
scientific evidence to show that slugs are directly impacting the four
orchids (Bulbophyllum guamense, Dendrobium guamense, Nervilia
jacksoniae, and Tuberolabium guamense) addressed in this rule.
Our Response: We acknowledge that we do not have direct evidence of
slug herbivory specific to the four orchid species considered here.
However, these mollusks are well-known pests of orchids throughout the
world (Hamom 1995, pp. 45-46; Hollingsworth and Sewake 2002, pp. -2;
Joe and Daehler 2008, pp. 245-255) and of a variety of plants on Rota
(Badilles et al.2010, pp. 2-7; Cook 2012, in litt). Therefore, based on
the known presence of nonnative slugs on Rota and their known habitat
of consuming orchids, we believe it is reasonable to conclude that slug
herbivory is a threat to the four orchid species on the island of Rota.
(66) Comment: The CNMI DLNR stated that they concur with regional
experts and the proposed rule regarding the significant threat posed by
the Platydemus flatworm to the tree snail species proposed for listing
(Liske-Clark, in prep.).
Our Response: We appreciate receiving the Department's assessment
of the threats to the tree snails that we are listing via this final
rule.
(67) Comment: The CNMI Department of Land and Natural Resources
challenged the claim that current regulatory mechanisms in place in the
CNMI are modestly enforced and are currently inadequate to protect the
16 (sic) CNMI species.
Our Response: The proposed rule and this final rule identify the
spread of nonnative plants and animals as the primary example as to why
we consider CNMI regulations to be modestly enforced and inadequate.
After receiving comments on the proposed rule, we have added that a
paucity of funding availability and human resources hinders the
enforcement of regulations (CNMI DLNR-Rota 2015, in litt.). We
acknowledge that addressing the magnitude and intensity of harmful
nonnative species (e.g., brown treesnakes, aulacaspis scale, flatworms,
and plants such as Chromolaena odorata) and their continual spread in
the Marianas is a daunting and challenging task. However, this ongoing
problem indicates that existing regulatory mechanisms have not curbed
the impact or spread of these species. Therefore, current regulatory
mechanisms are considered inadequate at this time.
(68) Comment: The CNMI DLNR concurred that limited numbers is a
threat for the Rota blue damselfly, Langford's tree snail, and fragile
tree snail. However, the Department noted that the threat of limited
numbers for the fragile tree snail is listed in Table 3, but is not
included in the description of threats.
Our Response: We have corrected this oversight in the text of this
final listing rule (see Table 3 and Summary of Changes from the
Proposed Rule, above).
(69) Comment: The CNMI DLNR is unaware of any vandalism ever
occurring on Rota targeting Tabernaemontana rotensis and suggested that
the only reason why vandals might specifically target T. rotensis, or
any particular species, would be its current or proposed status under
the Act.
Our Response: Vandalism of federally listed plant populations is
well-documented across the United States, and there was an occurrence
of vandalism to Tabernaemontana rotensis in the late 1990s (Hess and
Pratt 2006, p. 33). However, we have concluded that vandalism is not an
imminent threat to Tabernaemontana rotensis since there have been no
documented occurrences since that time and have, therefore, removed
this threat for this species from Table 3 and Factor E, above.
(70) Comment: The CNMI DLNR stated that they have no evidence of
ordnance directly impacting Cycas micronesica or Heritiera
longipetiolata in the CNMI. The Department stated that, while ordnance
use may be a potential threat on Pagan and Tinian in the future, they
did not believe ordnance is a current or potential threat on any other
island in the CNMI.
Our Response: Our information regarding current and future planned
military activity on Guam and within the CNMI indicate that Cycas
micronesica and Heritiera longipetiolata are at risk of likely impacts
from ordnance on the islands of Guam and Tinian, respectively. Damage
to both C. micronesica and H. longipetiolata by ordnance and live-fire
has been observed near a firing range on Andersen AFB (Guam DAWR 2013,
in litt.).
(71) Comment: The CNMI DLNR reported a new occurrence for
Dendrobium guamense with three individuals of Dendrobium guamense
observed on the island of Aguiguan.
Our Response: We have updated this final rule to include Aguiguan
within the range of this species (see Description of the 23 Mariana
Islands Species, Table 1, and Summary of Changes from the Proposed
Rule, above).
(72) Comment: The CNMI DLNR reported a new occurrence for the Rota
blue damselfly in a separate stream not used for water consumption on
Rota, and commented that this second occurrence suggests the threat of
water extraction is not as severe as stated in the proposed rule. The
Department recommended that all streams of the Talakhaya region of Rota
be surveyed for the damselfly in order to determine the full
distribution of this species. Additionally, the Department noted that
surveys should be conducted along streams on Saipan and the Talofofo
watershed on Guam.
Our Response: We have added this new occurrence information under
Description of the 23 Mariana Islands Species and Summary of Changes
from the Proposed Rule, above. We agree with the Department that
additional surveys for the damselfly are desirable and would enhance
our understanding of this species' status and biology. However, under
the Act, we are required to make listing determinations on the basis of
the best available scientific and commercial data available (see 16
U.S.C. 1533(a)(1) and (b)(1)(A)). While we appreciate learning of the
new occurrence, the observation of a single additional individual is
not sufficient to change our conclusion that the threat of water
extraction is any less. The fact remains that the vast majority of
known individuals representing the entire species is found on a stream
that is used for water consumption on Rota, and thus this factor
remains a significant threat.
(73) Comment: The CNMI DLNR stated that they had not seen much
public engagement, education or outreach for the community of Rota with
regard to the proposed rule. They noted that the Service came to the
DLNR office for a 2-day visit, but expressed the opinion that this was
not sufficient for a rulemaking that would create a great impact on
cultural, social, economic,
[[Page 59485]]
and environmental resources in the future.
Our Response: We regret that the CNMI DLNR feels our outreach
efforts have been insufficient. The Service initiated communication
regarding this rulemaking with the CNMI DLNR starting as early as
spring 2012, including the Secretary and supervisory biologist. The
CNMI DLNR supervisory biologist assisted our biologists in the field on
Saipan during July 2012 and was invited to review and comment on their
survey trip report (Harrington et al. 2012, in litt.), which included
not only the 14 plants listed in this final rule, but 17 additional
plants that were considered for conservation actions at that time.
Similarly, the CNMI DLNR Division of Fish and Wildlife on Rota
collaborated with our field biologists in 2012, and were also asked to
review and comment on the plant species. Our biologists also met with
the CNMI DLNR Division of Forestry on Rota in 2012 to discuss the
status of 31 Mariana Islands plant species considered for conservation
actions.
In November 2012, our Deputy Field Supervisor--Programmatic
Division and Acting Deputy Field Supervisor--Geographic Program had a
meeting each with the Secretary of CNMI DLNR and the Mayor of Rota, in
which the potential listing of these species was mentioned. In June
2013, they met with the Secretary and Mayor of Rota again, and provided
a briefing paper regarding the 23 species. In January of 2014, our
Acting Deputy Field Supervisor--Geographic Program, along with several
staff biologists, met with the Mayor of Saipan, the Mayor of Tinian,
and the Mayor of Rota along with the Rota Division of Fish and Wildlife
and Division of Forestry, specifically to discuss the 23 species. In
May 2014, prior to the publication of the proposed rule, we held two
public information meetings, one each on Guam and Saipan, in order to
inform the public and answer questions about the 23 species and listing
process. Also in May 2015, our Field Supervisor and Deputy Field
Supervisor--Programmatic Division and Acting Deputy Field Supervisor--
Geographic Program briefed the CNMI Legislature, and met with the CNMI
DLNR on Saipan, to discuss the status of the 23 species, answer
questions, and gain information on one or more of the 23 species and
conservation issues. In July 2014, our Field Supervisor and Deputy
Field Supervisor--Programmatic Division met with the Legislative
Representative from Rota regarding the orchids. Upon the publication of
the proposed rule (October 1, 2014), we published news releases in the
Marianas Variety, Marianas Variety Guam, and Pacific Daily News.
Due to requests received during the first comment period, we
reopened the comment period for an additional 30 days (January 12,
2015, through February 11, 2015); and in January 2015, held two public
hearings (one each on Guam and Saipan), and four public information
meetings (one each on the islands of Guam, Rota, Saipan, and Tinian).
The public information meeting on Rota had 11 attendees. Additionally,
most of the species addressed in this final rule that occur on Rota are
found within existing conservation boundaries or designated critical
habitat. Any future targeted conservation measures on Rota will likely
occur within these areas and, therefore, minimize impacts to the local
community. Further, once a species is listed, for private or other non-
Federal property owners we offer voluntary safe harbor agreements that
can contribute to the recovery of species, habitat conservation plans
(HCP) that allow activities (e.g., grazing) to proceed while minimizing
effects to species, funding through the Partners for Fish and Wildlife
Program to help promote conservation actions, and grants to the States
under section 6 of the Act. Overall, the Service has attempted to
inform and engage the community of Rota to the extent possible, and we
look forward to continue working with the CNMI DLNR and the members of
the local community for the conservation of native species on Rota.
(74) Comment: The CNMI DLNR submitted comment with the suggestion
that the Endangered Species Act (the Act) be modified to accommodate
different situations because it believes the way the ESA is currently
written and applied is limited by its one-size-fits-all approach.
Our Response: Changing the Act requires a legislative action by the
United States Congress and is beyond the scope of this listing action.
(75) Comment: A member of the CNMI Legislature commented that the
CNMI is slowly rebounding from a slow and weakened economy, and that
they are faced with significant economic challenges. In order to
address these issues, the Government approved a series of proposed
developments that include the construction of 2,000-plus integrated
casino resorts at various locations yet to be determined, themed
entertainment facilities, beverage outlets, villas, chapels, and sports
facilities that are to be built at other locations. This commenter
stated that it is inevitable that listing species for protection and
conservation will place stumbling blocks for economic prosperity for
the people of the Commonwealth.
Our Response: The Act requires that our listing determinations be
based solely on the best scientific and commercial data available. The
Act does not allow us to consider the impacts of listing on economics
or human activities whether over the short term, long term, or
cumulatively.
(76) Comment: Two commenters, the CNMI DLNR and a representative of
the CNMI legislature, commented that the Service must provide the
financial resources to effectively carry out and enforce Federal
conservation programs in the CNMI. This added task, absent financial
support, is counterproductive. The CNMI DLNR is understaffed and
underfunded. The representative from the Legislature further commented
that Federal conservation programs in the CNMI are being hampered due
to being understaffed and no or under-appropriated Federal financial
support; and, therefore, the Service should not depend solely on data
collected from the CNMI DLNR Division of Fish and Wildlife.
Our Response: The Service does not solely rely on any one source to
inform our proposals or to make a determination. We rely on the best
scientific and commercial data available at the time of our decision;
that data may come in many forms and from multiple sources. In this
case, we have relied on peer-reviewed published articles, unpublished
research, habitat modeling reports, digital data publicly available on
the Internet, and the expert opinions from specialized biologists to
determine the status of the 23 species. Regarding funding, the Service
provides funding to CNMI DLNR and other local conservation programs
such as the brown treesnake program, and pending our future budget,
which changes annually, we intend to allocate funds to assist with
actions that aim to recover the 23 species addressed in this final
rule. The funding of the CNMI DLNR is outside the scope of this
rulemaking.
(77) Comment: A representative from the CNMI legislature and one
public commenter stated that it was difficult to navigate the methods
provided to the public to make a comment. The Web sites and addresses
are long and confusing, technology is limited in many areas of the
CNMI, and small community voices likely will not be heard. People would
like to comment, but do not understand how or where, or even what
impacts would result from the listing of the 23 species. People also do
not understand how these species reached being considered for
[[Page 59486]]
endangered or threatened status, or what these species even look like.
Our Response: Please see our response to comment (73), above, where
we outline the multiple public information meetings held to inform the
public and answer questions. At all of these meetings, we provided
contact information, information about the 23 species (including
pictures), and explained why they were being considered for listing as
threatened or endangered species. We also had biologists present to
explain the listing process and answer questions to members of the
public. The public information meetings held in January 2015 on Guam,
Saipan, Rota, and Tinian were held during the second open comment
period, and we accepted written comments at those meetings. We also
held public hearings, at which members of the public could present
their comments orally if they preferred to do so. We have provided
multiple opportunities to inform the public, answer their questions,
and submit comments regarding the proposed rule. We always appreciate
feedback on how we can improve our outreach efforts.
(78) Comment: A representative of the CNMI legislature and a public
commenter requested that the Service separate out the 16 plants and
animals that were not previously candidate species, and assign them a
totally different process, and only move on with the 7 candidate
species at this time. CNMI biologists have conducted surveys that found
there are many more individuals of some species than what was stated in
the proposed rule. More research is needed to determine whether or not
the additional 16 species warrant listing.
Our Response: We included the additional 16 species in this listing
package for the sake of efficiency and saving taxpayer dollars. We
evaluated these species under the same standards and with the same
rigor outlined in the ESA that we apply to all species under
consideration for listing, whether previous candidates or not. Under
the Act, we determine whether a species is an endangered species or a
threatened species because of any of five factors, and we are required
to make listing determinations solely on the basis of the best
available scientific and commercial data available [emphasis ours]
(sections 4(a)(1) and 4(b)(1)(A)). Further, our Policy on Information
Standards under the Act (published in the Federal Register on July 1,
1994 (59 FR 34271)), the Information Quality Act (section 515 of the
Treasury and General Government Appropriations Act for Fiscal Year 2001
(Pub. L. 106-554; H.R. 5658)), and our associated Information Quality
Guidelines (www.fws.gov/informationquality/), provide criteria and
guidance, and establish procedures to ensure that our decisions are
based on the best scientific data available. They require our
biologists, to the extent consistent with the Act and with the use of
the best scientific and commercially available data, to use primary and
original sources of information as the basis for recommendations to
list a species.
In accordance with our peer review policy published on July 1, 1994
(59 FR 34270), we solicited peer review from knowledgeable individuals
with scientific expertise that included familiarity with the species,
the geographic region in which the species occurs, and conservation
biology principles. Additionally, we requested comments or information
from other concerned governmental agencies, the scientific community,
industry, and any other interested parties concerning the proposed
rule. Comments and information we received helped inform this final
rule. We have incorporated all new information, including the studies
conducted by CNMI DLNR biologists, under Description of the 23 Mariana
Islands Species and Summary of Biological Status and Threats Affecting
the 23 Mariana Islands Species, above; and we discuss our rationale for
retaining the species that are more abundant than previously described
in the proposed rule under Summary of Changes from the Proposed Rule,
above. Therefore, in this final rule, we have made our determination to
list the 23 species as threatened or endangered species based on the
best scientific and commercial data available.
Please see also our responses to comments 4, 45, and 47, above.
(79) Comment: A representative of the CNMI legislature expressed
concern that more land on Rota will be set aside if the listings are
finalized, especially due to the recent large piece of public land set
aside on Rota to mitigate for the Mariana crow that is listed as
endangered. Additionally, there was a recent Federal law passed by
Congress authorizing a feasibility study for a National Park monument
on Rota.
Our Response: We understand that there is concern about the
potential consequences following the listing of these 23 species.
However, the direct effect of this rulemaking is limited to placing
these 23 species on the Federal Lists of Endangered and Threatened
Wildlife and Plants, which in turn affords them protections under
sections 7 and 9 of the Federal Endangered Species Act . The listing of
these species does not carry with it any automatic requirement that
additional land be set aside on Rota for the purposes of conservation.
Should the listing of these species initiate some interest by the local
government or some other entity in potentially setting aside some
additional lands for conservation, such an action would entail an
entirely separate endeavor and legal process from this rulemaking.
Comments From Federal Agencies
Comments From the U.S. National Park Service
(80) Comment: The U.S. National Park Service (NPS) commented that
they concur with the proposed rule to add these 23 species to the
Federal Lists of Endangered and Threatened Wildlife and Plants. Of the
23 species, the NPS Monitoring and Inventory Program and War in the
Pacific National Historical Park (NHP) staff have recently found three
plant species present on park land on Guam (Cycas micronesica,
Tinospora homosepala, and Phyllanthus saffordii). Also, they suggest
that the plant Hedyotis megalantha is probably present in the park as
the park contains appropriate habitat that is likely supporting the
occurrence of that species. A small population of the Guam tree snail
is also present in at least one site in the park. The humped tree snail
has been recorded recently in American Memorial Park on Saipan.
Our Response: We appreciate being informed regarding species
status, threats, and numbers. The presence of the three plants and Guam
tree snail at War in the Pacific NHP on Guam, and the presence of the
humped tree snail at American Memorial Park on Saipan, were included in
our analyses published in the proposed rule. The NPS participated in
meetings with the Service and other Federal and State partners during
the information-seeking stage of the proposed rule.
Comments From the U.S. Navy
(81) Comment: The U.S. Navy requested that we correct the
description of the Marine Corps relocation and, specifically,
recommended citing the Draft Supplemental EIS (SEIS) released in April
of 2014. The proposed action is to construct and operate facilities on
Guam (not Tinian) to support the training and operations of Marines.
Four ranges on Tinian were proposed in the original 2010 record of
decision (ROD); however, the training requirements satisfied by those
four ranges are now the subject of another EIS (CNMI Joint Military
Training, or CJMT) and, as such, are not
[[Page 59487]]
a part of the revised proposed action covered in the 2014 Draft SEIS
for the Marine Corps relocation to Guam. Additionally, the construction
of a deep-draft wharf in Apra Harbor and facilities to support the U.S.
Missile Defense Task Force is no longer proposed on Guam (and is not
addressed in the revised proposed action covered in the 2014 Draft
SEIS).
Our Response: We have incorporated these changes from the new 2014
Draft SEIS and the 2010 ROD under Historical and Ongoing Human Impacts,
above, and under Summary of Changes from the Proposed Rule, above.
(82) Comment: The U.S. Navy commented that the preferred
alternatives identified in the 2014 Draft SEIS for the Marine Corps
relocation to Guam include construction of a Marine Corps cantonment
(main base) at Naval Computer and Telecommunication Station Finegayan
and a live-fire training range on Andersen Air Force Base-Northwest
Field. Orote Point, Pati Point, and Navy Barrigada are not preferred
locations for any facilities to support the Marine Corps move. Andersen
South and the Naval Magazine were addressed in the 2010 ROD and, as
discussed in the 2014 Draft SEIS, action and activities at those two
locations are still proposed.
Our Response: We have updated our description of Historical and
Ongoing Human Impacts, above. Additionally, we have noted this change
under Summary of Changes from the Proposed Rule, above.
(83) Comment: The U.S. Navy acknowledged that many of the proposed
species occur on Department of Navy (DON) lands. Specifically, proposed
species that are known to occur on lands managed by Joint Regional
Marianas (JRM) include the plants Bulbophyllum guamense, Cycas
micronesica, Dendrobium guamense, Heritiera longipetiolata, Maesa
walkeri, Nervilia jacksoniae, Psychotria malaspinae, Tabernaemontana
rotensis, and Tuberolabium guamense; and the Mariana eight-spot
butterfly (and associated host plants Procris pendunculata and
Elatostema calcareum), humped tree snail, Guam tree snail, and the
fragile tree snail; as well as the host plant (Maytenus thompsonii) for
the Mariana wandering butterfly. Additionally, the previously listed
tree Serianthes nelsonii also occurs on JRM lands. They noted the
proposed plants Hedyotis megalantha and Phyllanthus saffordii may also
occur on lands managed by JRM.
Our Response: We appreciate the Navy's confirmation of those
species that are known to occur or may occur on JRM lands. We look
forward to collaborating with the JRM Natural Resource Program team to
plan and implement conservation measures to achieve the recovery of all
endangered and threatened species that occur on JRM lands.
(84) Comment: The U.S. Navy provided updated information on the
humped tree snail and Guam tree snail related to surveys conducted at
Haputo Ecological Reserve Area on Naval Base Guam Telecommunication
Site in 2014, and surveys all over Guam for the Federal Candidate
Species Survey and Monitoring on Guam, Monthly Report for August 2014
(Lindstrom and Benedict 2014).
Our Response: We have incorporated all new relevant data for the
humped tree snail and Guam tree snail under Description of the 23
Mariana Islands Species and Summary of Biological Status and Threats
Affecting the 23 Mariana Islands Species, above.
(85) Comment: The U.S. Navy commented that, in the section titled
Habitat Destruction and Modification by Development, Military Training,
and Urbanization, the proposed rule states that the northern two-thirds
of Tinian are leased by the Department of Defense, and the development
of these lands and effects from live-fire training will directly impact
the trees Heritiera longipetiolata (on Tinian) and Cycas micronesica
(on Pagan) and their habitat in the forest ecosystem. The Navy concurs
that there may be an impact during construction, dependent on the
location of ranges and the distribution of H. longipetiolata (Tinian)
and C. micronesica (Pagan). However, they believe it is unlikely that
live-fire training will impact these species since the ordnance or
small-arms will be directed into cleared impact areas. The same comment
applies to the humped tree snail and Slevin's skink on Pagan; both are
forest species, and only forest clearing (if needed for range
construction) may impact them.
Our Response: One of the primary threats to each of the 23 species
in the proposed rule is land clearing that results in direct loss of
habitat. We maintain our position regarding threats associated with
live-fire training for the above-mentioned species, as the risk of
direct damage from ricocheted bullets and misplaced ordnance cannot be
eliminated, nor can the associated risk of fire. Direct damage
resulting from live-fire training has been observed in the past to
individuals of Heritiera longipetiolata and Cycas micronesica at the
firing range adjacent to Tarague Beach, on Andersen Air Force Base,
Guam (GDAWR 2013, pers. comm.). Further, the direct trampling of
individuals and destruction of habitat from military personnel remain
threats to the above species. New information received during the first
comment period informed us that the humped tree snail has recently been
documented on Tinian. Therefore, land clearing and live-fire training
are also a threat to the humped tree snail on Tinian (see Description
of the 23 Mariana Islands Species, above, and Summary of Changes from
the Proposed Rule, above). The Service looks forward to further
collaboration with the DOD to develop strategies that simultaneously
support the DOD's mission-critical activities and avoid or minimize
impacts to listed, proposed, and candidate species, and their habitats.
(86) Comment: The U.S. Navy commented that, in the section titled
``Habitat Destruction and Modification by Introduced Ungulates,'' the
proposed rule does not report three epiphytic orchids (Bulbophyllum
guamense, Dendrobium guamense, and Tuberolabium guamense), the vine
Tinospora homosepala, the Mariana wandering butterfly and its host
plant Maytenus thompsonii, and the Rota blue damselfly to be vulnerable
to habitat modification and destruction caused by nonnative ungulates.
They point out that ungulates on Guam have modified the current forest
ecosystem, resulting in minimal regeneration of native tree species,
including those that are hosts for the epiphytic orchids and
butterflies; impacts from ungulates would be expected to impact these
species.
Our Response: When species face myriad threats, we focus on those
that pose the greatest risk to the species. Although the cumulative
scientific literature confirms the negative impacts on ecosystems
resulting from nonnative ungulates, we have no evidence at this time to
support assigning nonnative ungulates as a threat to the three
epiphytic orchids, nor the Mariana wandering butterfly and its host
plant Maytenus thompsonii. The Service exercises caution when assigning
a threat to a species. The three epiphytic orchids often occur high up
in the canopy far from the reach of ungulates, and the tree Maytenus
thompsonii does not yet appear to be impacted by ungulates to the
degree that we would consider the Marianas wandering butterfly to be
threatened by ungulates.
(87) Comment: The U.S. Navy commented that, although the proposed
rule states that Cycas micronesica and Heritiera longipetiolata have
been impacted from activities at a firing range near Tarague Beach
along the ridge line on Andersen Air Force Base Guam
[[Page 59488]]
(note: We assume the firing range referenced is Combat Arms Training
and Maintenance (CATM)]), JRM has not received any reports of damage to
these or any other proposed species in areas at or adjacent to the CATM
Range from training activities at this site. JRM conducted a survey of
the CATM Range on October 30, 2014, to assess the presence and relative
abundance of proposed species and to search for signs of impact from
activities at the range. Cycas micronesica was present at all areas
searched, with abundance ranging from 1individual to approximately 50
at each site. No evidence of range-related damage was observed to
individuals of C. micronesica, including no signs of damage from
ricochet bullets to cycads or other vegetation at any sites. Heritiera
longipetiolata was not observed at any sites. Considering the observed
abundance of the species proposed for listing, the absence of signs of
damage from range activities, and the type of training that occurs at
the range, impacts from activities at the CATM Range (including
ricochet bullets) it is not expected to present a significant threat to
the species proposed for listing. This finding is expected to also
apply to other ranges that currently exist on Guam due to the similar
type of training that occurs at these ranges.
Our Response: We appreciate the Navy's investigation into the
threat from live-fire weapons to Heritiera longipetiolata and Cycas
micronesica near Tarague Beach, and the recent update that live-fire is
not negatively impacting these species as described in the proposed
rule. The Service has taken this comment into consideration and has
omitted Tarague Beach from the sites where live-fire training and
ordnance are considered to negatively impact these two plant species.
However, due to the preferred site for the new live-fire range on
Northwest Field on Andersen AFB over the Guam National Wildlife Refuge,
and the associated proposed training activities on Pagan and Tinian,
the Service concludes that DOD ordnance and live-fire training remain a
threat to these two previously mentioned plant species (Cycas
micronesica (Northwest Field Andersen AFB) and Heritiera longipetiolata
(Tinian)), and has been added as a threat to the humped tree snail and
Slevin's skink, also addressed in this final rule, because they occur
on Pagan where live-fire training is planned as described in the CNMI
Joint Military Training Draft EIS/OEIS (http://www.cnmijointmilitarytrainingeis.com/about). Additionally, the plants
Psychotria malaspinae and Tabernaemontana rotensis and the Mariana
eight-spot butterfly occur within the suggested boundaries of the live-
fire training area on the Northwest Field on Andersen Air Force Base
(USFWS 2015, in litt.) and, therefore, are being assigned the threat
from live-fire training and ordnance.
Other threats to these seven species, and their habitats,
associated with DOD live-fire training include direct destruction by
land clearing, live-fire weapons training and possible fires caused by
this activity, or inadvertent trampling and destruction by military
personnel. The threat from live-fire training and ordnance to the
plants Cycas micronesica, Heritiera longipetiolata, and P. malaspinae,
and Tabernaemontana rotensis and the humped tree snail, Marianas eight-
spot butterfly, and Slevin's skink, listed as threatened or endangered
in this final rule, has been added to Table 3 and Summary of Biological
Status and Threats Affecting the 23 Mariana Islands Species, above.
These changes are also noted under Summary of Changes from the Proposed
Rule, above.
(88) Comment: The U.S. Navy commented that the JRM INRMP uses an
ecosystem approach to adaptively manage natural resources to protect
native species, including federally listed endangered, threatened, and
proposed species and their habitat. They describe the key components of
ecosystem management in the INRMP as: (1) Control and eradication of
ungulates (deer, pigs and carabao); (2) restoration and maintenance of
native forests; and (3) control and eradication of brown treesnakes
that will lead to the reintroduction of native forest birds and bats
and restore native habitat. Long-term forest management plans specific
to Andersen Air Force Base (AAFB) and Navy Base Guam (NBG) are under
development for the Guam National Wildlife Refuge Overlay lands,
including site-specific descriptions for the protection, restoration,
and enhancement of native forest as well as eradication of invasive
plants. The restoration of forest ecosystems will benefit the recovery
of ESA-listed species and proposed species. They further state that
funding has been programmed to support this work through 2020. For
example, the INRMP program will erect fencing on Andersen Air Force
Base and Navy Base Guam to exclude ungulates from native forest,
eradicate ungulates within fenced areas, and maintain ungulate
densities at near zero in non-fenced areas. So far, a 306-ac ungulate
fence has been initiated on AAFB. Additionally, ungulate control on
AAFB and NBG has been initiated, and eradication of ungulates in the
fenced areas will be initiated in FY2015. In the Marianas, JRM lands
include 53,709 terrestrial acres and 79,260 acres of submerged lands.
Some of the most environmentally sensitive areas on Guam and in the
CNMI, including habitat for proposed species, occur within these lands.
Our Response: We appreciate the update regarding conservation
activities and mitigation measures being implemented by the U.S. Navy
on AAFB and NBG and commend these efforts. We have added the new
exclosure information under the section ``Conservation Efforts to
Reduce Habitat Destruction, Modification, or Curtailment of Its
Range.'' Although the INRMP has not yet been approved by the Service,
we have taken all of the information provided by these comments into
consideration. We look forward to collaborating with the DOD to further
these conservation efforts in the Mariana Islands, and we are
continuing to coordinate with the U.S. Navy on the development of their
INRMP.
(89) Comment: The U.S. Navy commented that the JRM INRMP program is
funding research for large-scale suppression and eradication of brown
treesnakes. In FY 2014, the Navy funded $1.8M in projects to meet
objectives for control, suppression, and eradication of brown
treesnakes to benefit native species (including proposed species) and
their habitat. Funding has been programmed to continue this effort
through 2021. Additionally, in FY 2014 the Navy funded $3.3M for
control and containment to prevent the spread and establishment of
brown treesnakes to new areas, including the CNMI where species in this
rulemaking action occur.
Our Response: The eradication of brown treesnakes from Guam is a
priority of the Service, as well as preventing the spread and
establishment of brown treesnakes elsewhere, and the Service
appreciates the DOD's commitment. We have added the Navy's $5.1M
investment toward brown treesnake eradication under the section
``Conservation Efforts to Reduce Habitat Destruction, Modification, or
Curtailment of Its Range,'' above.
(90) Comment: The U.S. Navy commented that during FY 2014 JRM
executed projects targeting these species, such as partulid snail
surveys and predation studies, and will continue to do so in FY 2015.
During FY 2015 the JRM INRMP will be revised to specifically address
species proposed for ESA-listing as endangered or threatened that occur
on JRM lands.
[[Page 59489]]
This effort will continue JRM's commitment to conservation and recovery
of native species in the Marianas.
Our Response: We have incorporated all new relevant information
from the recent candidate surveys (NavFac, Pacific 2014, pp. 1-1--7-2,
and Appendix A; Lindstrom and Benedict 2014, pp. 1-44, and Appendices
A-E; Myounghee Noh and Associates 2014, pp. 1-28, and Appendices A-B)
into this final rule under Description of the 23 Mariana Islands
Species and Summary of Biological Status and Threats Affecting the 23
Mariana Islands Species, above. Significant changes are also noted
under Summary of Changes from the Proposed Rule, above.
(91) Comment: The U.S. Navy stated that JRM INRMP contains goals
and objectives specifically for Cycas micronesica and Tabernaemontana
rotensis. This includes a project that began in 2007 to collect cycad
germplasm from geographically and genetically diverse plants on Guam
and plant 1,000 saplings on Tinian to ensure a broad genetic
representation of Guam's cycads in a living seed bank. The collection
has been actively managed and expanded. In 2013 AAFB fenced five 1-ac
ungulate exclusion plots that contain approximately 1,000 mature cycad
plants. Cycads within the plots are actively managed to ensure health
and survival; funding has been programmed to support this project
through 2020. During FY2014 the Navy funded a project to examine the
distribution and abundance of T. rotensis and other proposed species on
JRM lands.
Our Response: We have incorporated the new cycad exclosures on
Tinian into this final rule under Conservation Efforts to Reduce
Disease and Predation, above.
Public Comments on the Proposed Listing of 23 Species
(92) Comment: Two commenters agreed that all 23 species face
threats of high magnitude and imminence, and that the cumulative
impacts on these species will take a heavy toll on their ability to
adapt and survive. One of the commenters suggested that human
population growth and a rising tourism industry will further hinder the
ability to control invasive species. Further, they stated that,
although the brown treesnake may not yet be found in the northern
Mariana Islands, the military expansion into these islands will
undoubtedly spread the invasion of this species. Further, they
suggested that the economic and environmental roles the 23 species play
in the ecosystem cannot be overlooked. The current rate of species
extinctions is more than 1,000 times greater than the background rate
calculated from the fossil record and genetic data that spans millions
of years (Pimm et al. 2014).
Our Response: We appreciate the concurrence regarding our analysis
for each of the 23 species, and we recognize the threat posed by the
potential spread of the brown treesnake onto islands where it does not
yet occur. The Act requires us to make listing decisions based solely
on the best scientific and commercial data available; considerations
such as the potential economic role of a species in an ecosystem cannot
enter into a listing determination.
(93) Comment: Several commenters expressed concern that more
listing of endangered species will prevent landowners from building on
their own property. One of these commenters stated that the Fish and
Wildlife Service said he could not cut down trees or build a home on
his family's property due to the presence of the nightingale reed-
warbler (listed as an endangered species). The commenters suggested
propagating species to increase their populations as an alternative to
listing, and questioned why existing mitigation lands are not
sufficient to conserve these species.
Our Response: Programs are available to private landowners to
assist with managing habitat for listed species, as well as provide
permits to protect private landowners from the take prohibition when
such taking is incidental to, and not the purpose of, the carrying out
of an otherwise lawful activity (e.g., habitat conservation plans (HCP)
and safe harbor agreements (SHA)). Private landowners may contact their
local Service field office to obtain information about these programs
and permits. The Service believes that restrictions alone are neither
an effective nor a desirable means for achieving the conservation of
listed species. We are committed to working collaboratively with
private landowners, and strongly encourage individuals with listed
species on their property to work with us to develop incentive-based
measures such as SHAs or HCPs, which have the potential to provide
conservation measures that effect positive results for the species and
its habitat while providing regulatory relief for landowners. The
conservation and recovery of endangered and threatened species, and the
ecosystems upon which they depend, is the ultimate objective of the
Act, and the Service recognizes the vital importance of voluntary,
nonregulatory conservation measures that provide incentives for
landowners in achieving that objective.
Regarding proactive measures for species of concern, the Service
collaborates with and funds multiple programs that work on the
propagation and outplanting of threatened and endangered plants and
captive-breeding programs for threatened and endangered animals, as
well as for candidate species. However, while we agree that such
measures are often desirable and necessary to achieve the conservation
of the species, the Act does not allow for the pursuit of such
activities as an alternative to listing. The statute requires that we
consider whether a species is endangered or threatened as a result of
any of five threat factors, specifically: (A) The present or threatened
destruction, modification, or curtailment of its habitat or range; (B)
Overutilization for commercial, recreational, scientific, or
educational purposes; (C) Disease or predation; (D) The inadequacy of
existing regulatory mechanisms; or (E) Other natural or manmade factors
affecting its continued existence. If we conclude that the species in
question meets the definition of an endangered species or threatened
species, then that species is listed and receives Federal protections
under the Act. One component of these protections is the development of
a recovery plan, which may employ the conservation measures suggested
by the commenters, depending on the needs of the species. Additionally,
although existing mitigation lands can be used for conservation
actions, the availability of such lands may not be sufficient to offset
the full suite of threats that are negatively affecting the species
such that we would conclude listing is not warranted. For example,
mitigation lands may not provide enough resources or be large enough in
size to fully support the population sizes and distribution needed for
long-term viability of a species, or the nature of the stressor may be
such that mitigation lands do little to offset the threat (such as
impacts from manokwari flatworm predation on native tree snails). Thus,
while existing mitigation lands or conservation areas make an important
contribution to the conservation of these species, they are not
sufficient to address all of the threats leading to the determination
that these species are endangered or threatened, as defined by the Act.
(94) Comment: Several commenters stated that the proposed rule was
based on a lawsuit rather than science. Additionally, one commenter
expressed sincere disapproval of the ESA, primarily based on the
resulting need
[[Page 59490]]
for permits and difficulty to delist species.
Our Response: The timing of our proposed rule was based on a July
12, 2011, multiyear workplan filed as part of a settlement agreement
with the Center for Biological Diversity and others, in a consolidated
case in the U.S. District Court for the District of Columbia (In re
Endangered Species Act Section 4 Deadline Litigation, No. 10-377 (EGS),
MDL Docket No. 2165 (D.D.C. May 10, 2011), approved by the court on
September 9, 2011). The settlement enables the Service to
systematically, over a period of 6 years, review and address the needs
of more than 250 candidate species to determine if they should be added
to the Federal Lists of Endangered and Threatened Wildlife and Plants.
Addressing the seven candidate species is part of this settlement
agreement. However, it is important to note that these species were
already candidates for listing prior to the settlement, and were added
to the candidate list as a result of our earlier determination, based
solely on the best scientific and commercial data available, that they
meet the definition of endangered species or threatened species
according to the Act. Section 4 of the Act and its implementing
regulations (50 CFR part 424) set forth the procedures for adding
species to the Federal Lists of Endangered and Threatened Wildlife and
Plants. The listing process is not arbitrary, but uses the best
available scientific and commercial data and peer-review in
decisionmaking. In our proposed rule and this final rule, we have
adhered to all statutory requirements in evaluating the status of the
23 species addressed here, the 7 original candidate species as well as
16 additional species native to the Marianas, and in making our
determination that these species meet the definition of either
endangered species or threatened species under the Act.
The Service is fully committed to working with communities and
private landowners in partnership to minimize any impacts that may
potentially result from the listing of a species while achieving
conservation goals. For example, the Service works with landowners to
develop habitat conservation plans or safe harbor agreements, and
provide permits to private landowners for taking a listed species when
it is incidental to the carrying out of an otherwise lawful activity.
Private landowners may contact their local Service field office to
obtain information about these programs and permits. The Service
believes that restrictions alone are neither an effective nor a
desirable means for achieving the conservation of listed species. The
conservation and recovery of endangered and threatened species, and the
ecosystems upon which they depend, is the ultimate objective of the
Act, and the Service recognizes the vital importance of voluntary,
nonregulatory conservation measures that provide incentives for
landowners in achieving that objective.
The commenter's objections to the ESA in general are beyond the
scope of this rulemaking.
(95) Comment: One commenter stated that the Service is proposing to
double the number of listed species in the CNMI in one action. The
commenter further stated that most people in the Marianas do not have
the history or experience with the ESA listing process to be able to
absorb the magnitude of the detailed scientific information contained
in the proposed rule, and suggested the initial 60-day public comment
period was insufficient to review all of the detailed information,
including references cited, and provide comments.
Our Response: We appreciate the concern regarding public
understanding of the proposed rule. Public review and understanding is
important to us, which is why we extended the initial public comment
period by an additional 30 days, for a total of 90 days. We also held
two public hearings (one each on Guam and Saipan) and four public
information meetings (one each on Guam, Saipan, Rota, and Tinian) in
January 2015. These public information meetings were provided
specifically to address the concerns expressed by the commenter, and to
ensure that the public had an opportunity to fully understand our
proposal and engage in discussion or ask questions of Service staff.
Please see our response to comment (73), above, for a detailed summary
of outreach regarding the proposed rule. Further, all the handouts and
the proposed rule were made available to the public online at http://www.fws.gov/pacificislands/, and the Service is always available to
answer any questions from the public during normal business hours as
noted in the proposed rule.
(96) Comment: Two commenters expressed concern that the needs of
proposed or listed species are being placed above people's needs.
Our Response: The 23 species designated as threatened or endangered
species in this final rule are all species that occur in the Mariana
Islands and nowhere else in the entire world, with the exception of
Cycas micronesica, which is also found on Yap and in Palau. It is
accurate that the statute requires determinations as to whether species
merit the protections of the Act as an endangered species or threatened
species be based solely on scientific and commercial data, as that data
informs our evaluation of the threats affecting the species and their
conservation status. However, the Service is fully committed to working
with communities and private landowners in partnership to minimize any
impacts that may potentially result from the listing of a species while
achieving conservation goals. For example, the Service works with
landowners to develop safe harbor agreements or habitat conservation
plans as needed. The listing of the 23 species does not mean that
economic progress cannot be made or that private land cannot be
developed. Please also see our response to comment (93), above.
(97) Comment: One commenter stated there is not a recovery plan or
a realistic accurate target date of recovery for these species.
Our Response: Recovery plans are initiated upon the publication of
a final listing rule as funding is available.
(98) Comment: One commenter expressed concern that the species
proposed for listing that occur on Federal Government property are not
properly protected. This commenter offered an example, stating that on
Northwest Field on Andersen AFB a few hundred, or maybe thousands, of
Cycas micronesica trees were destroyed.
Our Response: The commenter did not provide information pertaining
as to how or when these cycads were purportedly destroyed. Department
of Defense lands often support many rare species because access is so
limited and they establish relatively large buffer areas that are often
left untouched. Thus, military actions can be beneficial to species and
their habitats, but they can also be destructive to species and their
habitats, as outlined under Summary of Biological Status and Threats
Affecting the 23 Mariana Islands Species, above. All Federal agencies
must consult with the Service, under section 7 of the Act, prior to
carrying out actions that may impact listed species. The Service
provides suggestions to avoid or minimize impacts to species, and
methods for mitigation when appropriate. In this particular case, as
Cycas micronesica was not a candidate species prior to being proposed
for listing as a threatened species in October 2014, the DOD was under
no obligation to conserve this species or consult with the Service
regarding the potential removal of Cycas micronesica trees. Thus if
such
[[Page 59491]]
actions did take place, we would have been unaware of them.
Determination
Section 4 of the Act (16 U.S.C. 1533), and its implementing
regulations at 50 CFR part 424, set forth the procedures for adding
species to the Federal Lists of Endangered and Threatened Wildlife and
Plants. Under section 4(a)(1) of the Act, we may list a species based
on (A) The present or threatened destruction, modification, or
curtailment of its habitat or range; (B) Overutilization for
commercial, recreational, scientific, or educational purposes; (C)
Disease or predation; (D) The inadequacy of existing regulatory
mechanisms; or (E) Other natural or manmade factors affecting its
continued existence. Listing actions may be warranted based on any of
the above threat factors, singly or in combination.
We have carefully assessed the best scientific and commercial
information available regarding the past, present, and future threats
to the 23 species listed as endangered or threatened species in this
final rule. We find that all 23 species face threats that are ongoing
and expected to continue into the future throughout their ranges from
the present destruction and modification of their habitats from
nonnative feral ungulates, rats, or nonnative plants (Factor A).
Destruction and modification of habitat by development, military
training, and urbanization is a threat to 13 of the 14 plant species
(Bulbophyllum guamense, Cycas micronesica, Dendrobium guamense, Eugenia
bryanii, Hedyotis megalantha, Heritiera longipetiolata, Maesa walkeri,
Nervilia jacksoniae, Phyllanthus saffordii, Psychotria malaspinae,
Solanum guamense, Tabernaemontana rotensis, and Tuberolabium guamense)
and to 8 of the 9 animal species (the Pacific sheath-tailed bat,
Slevin's skink, the Mariana eight-spot butterfly, the Rota blue
damselfly, the Guam tree snail, the humped tree snail, Langford's tree
snail, and the fragile tree snail). Habitat destruction and
modification from fire is a threat to nine of the plant species
(Bulbophyllum guamense, Cycas micronesica, Dendrobium guamense,
Hedyotis megalantha, Maesa walkeri, Nervilia jacksoniae, Phyllanthus
saffordii, Tabernaemontana rotensis, and Tuberolabium guamense) and two
tree snails (the Guam tree snail and the humped tree snail).
Destruction and modification of habitat from typhoons is a threat to
all 23 species, which are vulnerable as a result of past reductions in
population size and distribution. Rising temperatures and other effects
of projected climate change may impact all 23 species, but there is
limited information on the exact nature of impacts that these species
may experience. Although the specific and cumulative effects of climate
change on each of these 23 species are presently unknown, we anticipate
that these effects, if realized, will exacerbate the current threats to
these species (Factor A).
Overcollection for commercial and recreational purposes poses a
threat to all four tree snail species (the Guam tree snail, the humped
tree snail, Langford's tree snail, and the fragile tree snail) (Factor
B).
Predation or herbivory on 9 of the 14 plant species (Bulbophyllum
guamense, Cycas micronesica, Dendrobium guamense, Eugenia bryanii,
Heritiera longipetiolata, Nervilia jacksoniae, Psychotria malaspinae,
Solanum guamense, and Tuberolabium guamense) and 8 of the 9 animals
(all except the Rota blue damselfly) by feral pigs, deer, brown
treesnakes, rats, monitor lizards, slugs, flatworms, ants, or wasps
poses a serious and ongoing threat (Factor C).
The inadequacy of existing regulatory mechanisms (i.e., inadequate
protection of habitat and inadequate protection from the introduction
of nonnative species) poses a serious and ongoing threat to all 23
species (Factor D).
There are serious and ongoing threats to three plant species
(Psychotria malaspinae, Solanum guamense, and Tinospora homosepala),
the fragile tree snail, Guam tree snail, Langford's tree snail, Mariana
eight-spot butterfly, Mariana wandering butterfly, Pacific sheath-
tailed bat, and Rota blue damselfly, due to small numbers of
populations and individuals; to Cycas micronesica, Heritiera
longipetiolata, Psychotria malaspinae, Tabernaemontana rotensis, the
humped tree snail, Mariana eight-spot butterfly, and Slevin's skink
from ordnance and live-fire training; to the Rota blue damselfly from
water extraction; and to Hedyotis megalantha and Phyllanthus saffordii
from recreational vehicles (Factor E) (see Table 3). These threats are
exacerbated by these species' inherent vulnerability to extinction from
stochastic events at any time because of their endemism, small numbers
of individuals and populations, and restricted habitats.
The Act defines an endangered species as any species that is ``in
danger of extinction throughout all or a significant portion of its
range'' and a threatened species as any species ``that is likely to
become endangered throughout all or a significant portion of its range
within the foreseeable future.'' We find that 16 of the 23 Mariana
Islands species are presently in danger of extinction throughout their
entire range, based on the severity and scope of the ongoing and
projected threats described above. These 16 species are: the 7 plants
Eugenia bryanii, Hedyotis megalantha, Heritiera longipetiolata,
Phyllanthus saffordii, Psychotria malaspinae, Solanum guamense, and
Tinospora homosepala; and all 9 animals: the Pacific sheath-tailed bat
(Emballonura semicaudata rotensis), Slevin's skink (Emoia slevini), the
Mariana eight-spot butterfly (Hypolimnas octocula marianensis), the
Mariana wandering butterfly (Vagrans egistina), the Rota blue damselfly
(Ischnura luta), the Guam tree snail (Partula radiolata), the humped
tree snail (Partula gibba), Langford's tree snail (Partula langfordi),
and the fragile tree snail (Samoana fragilis). We conclude these 16
species are endangered due to the small number of individuals
representing the entire species and the limited or concentrated
geographic distribution of those remaining individuals or populations,
rendering the species in its entirety highly susceptible to extinction
as a consequence of these imminent threats. These threats are
exacerbated by the loss of redundancy and resiliency of these species,
and the continued inadequacy of existing protective regulations.
Therefore, on the basis of the best available scientific and commercial
information, we have determined that each of these 16 species meets the
definition of an endangered species under the Act. We find that
threatened species status is not appropriate for these 16 species, as
the threats are already occurring rangewide and are not localized,
because the threats are ongoing and expected to continue into the
future, and because the severity of the threats is so great that these
species are currently in danger of extinction. In addition, the
remaining populations of these species are so small that we cannot
conclude they are likely capable of persisting into the foreseeable
future in the face of the current threats. We, therefore, list these 16
species as endangered species in accordance with section 3(6) of the
Act.
As noted above, the Act defines a threatened species as any species
``that is likely to become endangered throughout all or a significant
portion of its range within the foreseeable future.'' We list seven
plant species as threatened species in accordance with section 3(6) of
the Act: Bulbophyllum guamense, Cycas
[[Page 59492]]
micronesica, Dendrobium guamense, Maesa walkeri, Nervilia jacksoniae,
Tabernaemontana rotensis, and Tuberolabium guamense.
Bulbophyllum guamenseis primarily known from Guam and Rota, with
the exception of a few herbarium records that report this species as
historically occurring on the islands of Pagan and Saipan. The
cumulative data (i.e., herbaria records, scientific literature, survey
reports, books, and interviews with local biologists; as well as direct
observations from Service and other biologists) show that Bulbophyllum
guamense historically occurred on clifflines encircling Guam, and on
the slopes of Mt. Lamlam and Mt. Almagosa; as well as across the Rota
Sabana and surrounding slopes. As recently as 1992, this species was
reported to occur in large mat-like formations on trees ``all over the
island'' (Guam) (Raulerson and Rinehart 1992, p. 90). While the number
of B. guamense individuals on Guam are low, the number of individuals
on the Rota Sabana is much higher, with a relatively healthy population
structure consisting of juveniles and adults (Zarones et al. 2015c, in
litt.). Almost all of the individuals of B. guamense on Rota occur
within the boundaries of the Sabana Conservation Area, which also
encompasses much of the designated critical habitat for the Rota white-
eye (Zosterops rotensis) and Mariana crow (Corvus kubaryi) (listed as
endangered).
Although more than 50 percent of the range of B. guamense occurs on
Guam, where this species has experienced a significant decline in
number of individuals and populations due to threats predominantly
associated with habitat destruction and modification (i.e., urban
development, military development and training, brown treesnake,
nonnative plants, fire, typhoons, and climate change), this species
appears to be relatively healthy on Rota. However, due to the presence
of threats similar to those on Guam (i.e., habitat destruction and
modification from nonnative plants and animals (rats), fire, typhoons,
and climate change; and herbivory by invertebrates such as slugs),
populations of B. guamense on Rota remain highly vulnerable. We
conclude that, given its relatively greater population size on Rota,
with a healthy population structure, B. guamense is not currently in
danger of extinction; thus endangered status is not appropriate.
However, given that we are unaware of any conservation actions being
implemented at this time to abate the threats to B. guamense on Rota,
and the best available scientific and commercial information indicates
that the cumulative effects of the threats are so great the species
will become in danger of extinction in the foreseeable future, we
conclude that Bulbophyllum guamense meets the definition of a
threatened species under the Act.
Cycas micronesica occurs on Guam, Rota, and tentatively Pagan in
the CNMI, as well as on islands in the nations of Palau and Yap. More
than 50 percent of the known individuals occur on Guam and Rota in the
CNMI, and are currently impacted by the cycad aulacaspis scale to the
extent that botanists estimate the species could be largely extirpated
from these two islands within 4 years, by 2019. The status of the
tentative individuals of this species on Pagan is unknown, although
only a small population is believed to occur on that island. While the
cycad aulacaspis scale has reached the larger islands of Palau, it has
not yet reached the Rock Islands of Palau, or Yap, and these islands
may afford some temporary protection for the remaining individuals
while control methods and biocontrols for the cycad aulacaspis scale
are undergoing research. Due to the rapid spread of the scale and
associated high mortality, populations in Palau and Yap remain highly
vulnerable. Given its relatively greater population size and
distribution on multiple islands, some of which have not yet been
affected by the cycad aulacaspis scale, we conclude that Cycas
micronesica is not currently in danger of extinction, thus endangered
status is not appropriate. However, given the observed rapid spread of
the cycad aulacaspis scale, the likelihood that the scale will soon be
transported to areas that are currently unaffected, and the high
mortality rate experienced by Cycas micronesica upon exposure to the
scale, we conclude that Cycas micronesica is likely to become in danger
of extinction within the foreseeable future, and thus meets the
definition of a threatened species under the Act.
Dendrobium guamense predominantly occurs on the islands of Guam and
Rota, with a few scattered occurrences on Tinian and Aguiguan.
Historically, it also occurred on Saipan and possibly Agrihan. During
the 1980s, this species was common in trees on Guam and Rota (Raulerson
and Rinehart 1992, p. 98; Consortium Pacific Herbarium (CPH) 2012a--
Online Herbarium Database, 5 pp.; Costion and Lorence 2012, p. 66).
Currently, the populations of D. guamense on Guam, which comprise more
than 50 percent of its known range, have declined to low numbers due to
threats predominantly associated with habitat destruction and
modification (i.e., development, military training, nonnative plants
and animals (brown treesnake), fire, typhoons, and climate change)
(Harrington et al. 2012, in litt.). This species is abundant with
healthy population structure on the island of Rota (Zarones et al.
2015c, in litt.). However, due to the presence of threats similar to
those that occur on Guam (i.e., habitat destruction and modification
from nonnative plants and animals (rats), fire, typhoons, and climate
change; and predation by nonnative invertebrates such as slugs), D.
guamense remains highly vulnerable on Rota. Additionally, two or more
threats exist on all islands on which D. guamense is known to occur
(historically or present) (see Table 4, above). Raulerson and Rinehart
(1992, p. 87), two renowned botanists who have studied extensively in
the Marianas, stated that, although these orchids (referring to native
orchids in the Marianas) appear abundant, the habitats are limited and
in reality these orchids are quite rare. They also stated that the
islands are small and habitats are rapidly being destroyed by human
activity; thus these orchids can be considered rare. We conclude that,
given its relatively large population size and distribution on multiple
islands, and the healthy population structure on Rota, Dendrobium
guamense is not currently in danger of extinction; thus endangered
status is not appropriate. However, given the myriad threats imposed
upon this species throughout its range, and the fact that D. guamense
has significantly declined throughout more than 50 percent of its
entire range, we have determined that D. guamense is likely to become
in danger of extinction within the foreseeable future, and thus meets
the definition of a threatened species under the Act.
Maesa walkeri occurs on the islands of Guam and Rota. Once
relatively abundant on both of these islands, this species has since
been reduced to extremely low numbers on Guam, which represents more
than 60 percent of its former known range. On Rota, there are at least
684 individuals of Maesa walkeri in the Sabana region displaying a
healthy population structure including seedlings, juveniles, and
flowering adults (Liske-Clark et al. 2015, in litt.). Local biologists
estimate the actual number to be in the thousands (Liske-Clark et al.
2015, in litt.), and we concur with this estimate. Despite the relative
abundance and seemingly healthy population structure of Maesa walkeri
on Rota, this species remains vulnerable on this island due to
[[Page 59493]]
habitat destruction and modification by nonnative plants and animals
(rats and Philippine deer), fire, typhoons, and climate change. Given
its relative abundance and health on Rota, we conclude that Maesa
walkeri is not currently in danger of extinction, thus endangered
status is not appropriate. However, given the substantial decline in
number of individuals on Guam (only two individuals known to remain)
due to habitat destruction and modification by urban development,
military training and development, nonnative plants and animals (i.e.,
brown treesnake, pigs, and water buffalo), fire, typhoons, and climate
change; the fact that Guam accounts for more than 60 percent of the
known range for Maesa walkeri; and the presence of similar threats on
Rota, we have determined that Maesa walkeri is likely to become in
danger of extinction within the foreseeable future, and thus meets the
definition of a threatened species under the Act.
Nervilia jacksoniae is known from the islands of Guam and Rota, and
is the only endemic terrestrial orchid in the Mariana Islands. This
species was once abundant on Guam and Rota, and has since declined to
low numbers on Guam, which represents more than 60 percent of its
former known range. Populations on Guam face threats associated with
habitat destruction and modification by development, military training,
nonnative plants and animals (i.e., pigs, deer, water buffalo, and
brown treesnake), fire, typhoons, and climate change; as well as
herbivory by nonnative invertebrates such as slugs. Although relatively
healthy populations can still be found on Rota (Zarones et al. 2015d,
in litt.), these individuals face threats similar to those that occur
on Guam (i.e., habitat destruction and modification from nonnative
animals (deer and rats) and plants, fire, typhoons, and climate
change), and thus remain vulnerable. Given the relatively large and
healthy populations on Rota, we conclude that Nervilia jacksoniae is
not currently in danger of extinction, thus endangered status is not
appropriate. However, given the substantial loss of individuals on
Guam, which consists of at least 60 percent of its known range,
combined with the myriad threats imposed upon Maesa walkeri throughout
its range, we have determined that this species is likely to become in
danger of extinction within the foreseeable future, and thus meets the
definition of a threatened species under the Act.
Tabernaemontana rotensis was, until recently, believed to be part
of the wider ranging T. pandacaqui, until genetic studies showed it to
be unique to Guam and Rota. There may be as many as 8,000 individuals
on Guam with a healthy population structure, but there are only a few
individuals on Rota. The threats of habitat destruction and
modification by nonnative plants and animals, fire, typhoons, climate
change, and inadequate regulatory mechanisms exist throughout its
range. Additionally, habitat destruction and modification from urban
and military development, and military training, further negatively
impact this species on Guam. Given the relatively large and healthy
population of T. rotensis on Guam, even in the face of current threats,
we conclude that T. rotensis is not currently in danger of extinction;
thus endangered status is not appropriate. However, because the species
has been reduced to only a few individuals on Rota, and the remaining
population on Guam is subject to a suite of ongoing threats as
described above, we conclude that Tabernaemontana rotensis is likely to
become in danger of extinction within the foreseeable future.
Therefore, on the basis of the best available scientific and commercial
information, we determine that this species meets the definition of a
threatened species under the Act.
Tuberolabium guamense is predominantly known from the islands of
Guam and Rota, with a few scattered historical occurrences on Tinian
and Aguiguan. This species was once relatively abundant within
specialized habitat on Guam and Rota, but has since declined
substantially on Guam, which comprises more than 50 percent of its
known former range. On Guam, the habitat upon which this species
depends is experiencing destruction and modification by urban
development, military development and training, nonnative plants and
animals (brown treesnake), fire, typhoons, and climate change.
Tuberolabium guamense is still relatively abundant on Rota, with a
population structure consisting of juveniles and flowering adults
(Zarones et al. 2015c, in litt.). Observations made during recent
surveys indicate that this is the only endemic epiphytic orchid in the
Marianas that is solely found in native trees (Zarones et al. 2015c, in
litt.). Although T. guamense appears relatively healthy on Rota, its
habitat on this island is experiencing destruction and modification
from nonnative animals (deer and rats) and plants, fire, typhoons, and
climate change. Tuberolabium guamense is also at risk from herbivory by
nonnative invertebrates such as slugs. Additionally, more than 20 years
ago Raulerson and Rinehart (1992, p. 87) stated that, although these
orchids may appear abundant on the limestone ridges of Guam and Rota,
the habitats are limited and in reality these orchids are very rare. We
conclude that, given its relative abundance and health on Rota, T.
guamense is not currently in danger of extinction; thus endangered
status is not appropriate. However, due to the substantial loss of
individuals on Guam, which consists of at least 60 percent of its known
range, combined with the myriad threats imposed upon T. guamense
throughout its range, we have determined that this species is likely to
become in danger of extinction within the foreseeable future, and thus
meets the definition of a threatened species under the Act.
Under the Act and our implementing regulations, a species may
warrant listing if it is endangered or threatened throughout all or a
significant portion of its range. Because we have determined that each
of the 23 Mariana Islands species is either endangered or threatened
through all of its range, no portion of its range can be
``significant'' for the purposed of the definition of ``endangered''
and ``threatened'' species. See the Final Policy on Interpretation of
the Phrase ``Significant Portion of Its Range'' in the Endangered
Species Act's Definitions of ``Endangered Species'' and ``Threatened
Species'' (79 FR 37577).
Available Conservation Measures
Conservation measures provided to species listed as endangered or
threatened under the Act include recognition, recovery actions,
requirements for Federal protection, and prohibitions against certain
practices. Recognition through listing results in public awareness, and
conservation by Federal, State, and local agencies, private
organizations, and individuals. The Act encourages cooperation with the
States and territories and requires that recovery actions be carried
out for all listed species. The protection required by Federal agencies
and the prohibitions against certain activities are discussed, in part,
below.
The primary purpose of the Act is the conservation of endangered
and threatened species and the ecosystems upon which they depend. The
ultimate goal of such conservation efforts is the recovery of these
listed species, so that they no longer need the protective measures of
the Act. Subsection 4(f) of the Act requires the Service to develop and
implement recovery plans for the conservation of endangered and
threatened species. The recovery planning process involves the
identification of actions that are necessary to halt or reverse the
species'
[[Page 59494]]
decline by addressing the threats to its survival and recovery. The
goal of this process is to restore listed species to a point where they
are secure, self-sustaining, and functioning components of their
ecosystems.
Recovery planning includes the development of a recovery outline
shortly after a species is listed and preparation of a draft and final
recovery plan. The recovery outline guides the immediate implementation
of urgent recovery actions and describes the process to be used to
develop a recovery plan. Revisions of the plan may be done to address
continuing or new threats to the species, as new substantive
information becomes available. The recovery plan identifies site-
specific management actions that set a trigger for review of the five
factors that control whether a species remains endangered or may be
downlisted or delisted, and methods for monitoring recovery progress.
Recovery plans also establish a framework for agencies to coordinate
their recovery efforts and provide estimates of the cost of
implementing recovery tasks. Recovery teams (composed of species
experts, Federal and State agencies, nongovernmental organizations, and
stakeholders) are often established to develop recovery plans. When
completed, the recovery outline, draft recovery plan, and the final
recovery plan will be available on our Web site (http://www.fws.gov/endangered), or from our Pacific Islands Fish and Wildlife Office (see
FOR FURTHER INFORMATION CONTACT).
Implementation of recovery actions generally requires the
participation of a broad range of partners, including other Federal
agencies, States, territories, nongovernmental organizations,
businesses, and private landowners. Examples of recovery actions
include habitat restoration (e.g., restoration of native vegetation),
research, captive-propagation and reintroduction, and outreach and
education. The recovery of many listed species cannot be accomplished
solely on Federal lands because their range may occur primarily or
solely on non-Federal lands. To achieve recovery of these species
requires cooperative conservation efforts on all lands.
Following the publication of this final listing rule, funding for
recovery actions will be available from a variety of sources, including
Federal budgets, State programs, and cost-share grants for non-Federal
landowners, the academic community, and nongovernmental organizations.
In addition, pursuant to section 6 of the Act, the State(s) of the U.S.
Territory of Guam and the U.S. Commonwealth of the Northern Mariana
Islands would be eligible for Federal funds to implement management
actions that promote the protection or recovery of the 23 species.
Information on our grant programs that are available to aid species
recovery can be found at: http://www.fws.gov/grants.
Please let us know if you are interested in participating in
recovery efforts for this species. Additionally, we invite you to
submit any new information on these species whenever it becomes
available and any information you may have for recovery planning
purposes (see FOR FURTHER INFORMATION CONTACT).
Section 7(a) of the Act requires Federal agencies to evaluate their
actions with respect to any species that is listed as an endangered or
threatened species and with respect to its critical habitat, if any is
designated. Regulations implementing this interagency cooperation
provision of the Act are codified at 50 CFR part 402. Section 7(a)(4)
of the Act requires Federal agencies to confer with the Service on any
action that is likely to jeopardize the continued existence of a listed
species or result in destruction or adverse modification of designated
critical habitat. If a species is listed subsequently, section 7(a)(2)
of the Act requires Federal agencies to ensure that activities they
authorize, fund, or carry out are not likely to jeopardize the
continued existence of the species or destroy or adversely modify its
critical habitat. If a Federal action may affect a listed species or
its critical habitat, the responsible Federal agency must enter into
consultation with the Service.
For the 23 plants and animals listed as endangered or threatened
species in this rule, Federal agency actions that may require
consultation as described in the preceding paragraph include, but are
not limited to, actions within the jurisdiction of the Natural
Resources Conservation Service, the U.S. Army Corps of Engineers, the
U.S. Fish and Wildlife Service, and branches of the Department of
Defense (DOD). Examples of these types of actions include activities
funded or authorized under the Farm Bill Program, Environmental Quality
Incentives Program, Ground and Surface Water Conservation Program,
Clean Water Act (33 U.S.C. 1251 et seq.), Partners for Fish and
Wildlife Program, and DOD activities related to training, facilities
construction and maintenance, or other military missions.
The Act and its implementing regulations set forth a series of
general prohibitions and exceptions that apply to all endangered and
threatened wildlife and plants. The prohibitions of section 9(a)(1) of
the Act, and implemented at 50 CFR 17.21 for endangered wildlife, and
at Sec. Sec. 17.61 and 17.71 for endangered and threatened plants,
respectively, apply. For listed wildlife species, these prohibitions,
in part, make it illegal for any person subject to the jurisdiction of
the United States to take (includes harass, harm, pursue, hunt, shoot,
wound, kill, trap, capture, or collect; or to attempt any of these),
import, export, ship in interstate commerce in the course of commercial
activity, or sell or offer for sale in interstate or foreign commerce
any listed species. Under the Lacey Act (18 U.S.C. 42-43; 16 U.S.C.
3371-3378), it is also illegal to possess, sell, deliver, carry,
transport, or ship any such wildlife that has been taken illegally.
Certain exceptions apply to agents of the Service, the National Marine
Fisheries Service, other Federal land management agencies, and State
conservation agencies.
With respect to endangered plants, prohibitions outlined at section
9(a)(2) of the Act and 50 CFR 17.61 make it illegal for any person
subject to the jurisdiction of the United States to import or export,
transport in interstate or foreign commerce in the course of a
commercial activity, sell or offer for sale in interstate or foreign
commerce, or to remove and reduce to possession any such plant species
from areas under Federal jurisdiction. In addition, the Act prohibits
malicious damage or destruction of any such species on any area under
Federal jurisdiction, and the removal, cutting, digging up, or damaging
or destroying of any such species on any other area in knowing
violation of any State law or regulation, or in the course of any
violation of a State criminal trespass law. Exceptions to these
prohibitions are outlined in 50 CFR 17.62.
With respect to threatened plants, 50 CFR 17.71 provides that all
of the provisions in 50 CFR 17.61 shall apply to threatened plants.
These provisions make it illegal for any person subject to the
jurisdiction of the United States to import or export, transport in
interstate or foreign commerce in the course of a commercial activity,
sell or offer for sale in interstate or foreign commerce, or to remove
and reduce to possession any such plant species from areas under
Federal jurisdiction. In addition, the Act prohibits malicious damage
or destruction of any such species on any area under Federal
jurisdiction, and the removal, cutting, digging up, or damaging or
destroying of any such species on any other area in knowing violation
of any State law or regulation, or in the course of any violation of a
State criminal trespass law. However,
[[Page 59495]]
there is the following exception for threatened plants. Seeds of
cultivated specimens of species treated as threatened shall be exempt
from all the provisions of 50 CFR 17.61, provided that a statement that
the seeds are of ``cultivated origin'' accompanies the seeds or their
container during the course of any activity otherwise subject to these
regulations. Exceptions to these prohibitions are outlined in 50 CFR
17.72.
We may issue permits to carry out otherwise prohibited activities
involving endangered and threatened wildlife and plant species under
certain circumstances. Regulations governing permits are codified at 50
CFR 17.22 for endangered wildlife and at Sec. Sec. 17.62 and 17.72 for
endangered and threatened plants, respectively. With regard to
endangered wildlife, a permit must be issued for the following
purposes: For scientific purposes, to enhance the propagation or
survival of the species, and for incidental take in connection with
otherwise lawful activities. With regard to endangered plants, the
Service may issue a permit authorizing any activity otherwise
prohibited by 50 CFR 17.61 for scientific purposes or for enhancing the
propagation or survival of endangered plants. With regard to threatened
plants, a permit issued under this section must be for one of the
following: Scientific purposes, the enhancement of the propagation or
survival of threatened species, economic hardship, botanical or
horticultural exhibition, educational purposes, or other activities
consistent with the purposes and policy of the Act. Requests for copies
of the regulations regarding listed species and inquiries about
prohibitions and permits may be addressed to U.S. Fish and Wildlife
Service, Pacific Region, Ecological Services, Eastside Federal Complex,
911 NE. 11th Avenue, Portland, OR 97232-4181 (telephone 503-231-6131;
facsimile 503-231-6243).
It is our policy, as published in the Federal Register on July 1,
1994 (59 FR 34272), to identify to the maximum extent practicable at
the time a species is listed, those activities that would or would not
constitute a violation of section 9 of the Act. The intent of this
policy is to increase public awareness of the effect of a final listing
on proposed and ongoing activities within the range of a listed
species. The following activities could potentially result in a
violation of section 9 of the Act; this list is not comprehensive:
(1) Unauthorized collecting, handling, possessing, selling,
delivering, carrying, or transporting of the 23 species, including
import or export across State, Territory, or Commonwealth lines and
international boundaries, except for properly documented antique
specimens of these taxa at least 100 years old, as defined by section
10(h)(1) of the Act.
(2) Introduction of nonnative species that compete with or prey
upon the nine animal species, such as the introduction of competing,
nonnative plants or animals to the Mariana Islands (U.S. Territory of
Guam and U.S. Commonwealth of the Northern Mariana Islands).
(3) The unauthorized release of biological control agents that
attack any life stage of the nine animal species.
(4) Impacts to the nine animal species from destruction of habitat,
disturbance from noise (related to military training), and other
impacts from military presence.
Questions regarding whether specific activities would constitute a
violation of section 9 of the Act should be directed to the Pacific
Islands Fish and Wildlife Office (see FOR FURTHER INFORMATION CONTACT).
Requests for copies of the regulations concerning listed animals and
general inquiries regarding prohibitions and permits may be addressed
to the U.S. Fish and Wildlife Service, Pacific Region, Ecological
Services, Endangered Species Permits, Eastside Federal Complex, 911 NE.
11th Avenue, Portland, OR 97232-4181 (telephone 503-231-6131; facsimile
503-231-6243).
The Federal listing of the 23 species included in this final rule
may invoke Commonwealth and Territory listing under CNMI and Guam
Endangered Species laws (Title 85: Sec. 85-30.1-101 and 5 GCA Sec.
63205, respectively) and supplement the protection available under
other local law. These protections would prohibit take of these species
and encourage conservation by both government agencies. Further, the
governments are able to enter into agreements with Federal agencies to
administer and manage any area required for the conservation,
management, enhancement, or protection of endangered and threatened
species. Funds for these activities could be made available under
section 6 of the Act (Cooperation with the States and Territories).
Thus, the Federal protection afforded to these species by listing them
as endangered or threatened species will be reinforced and supplemented
by protection under Territorial and Commonwealth law.
Required Determinations
National Environmental Policy Act (42 U.S.C. 4321 et seq.)
We have determined that environmental assessments and environmental
impact statements, as defined under the authority of the National
Environmental Policy Act (NEPA; 42 U.S.C. 4321 et seq.), need not be
prepared in connection with listing a species as an endangered or
threatened species under the Endangered Species Act. We published a
notice outlining our reasons for this determination in the Federal
Register on October 25, 1983 (48 FR 49244).
References Cited
A complete list of references cited in this rulemaking is available
on the Internet at http://www.regulations.gov and upon request from the
Pacific Islands Fish and Wildlife Office (see FOR FURTHER INFORMATION
CONTACT).
Authors
The primary authors of this final rule are the staff members of the
Pacific Islands Fish and Wildlife Office.
List of Subjects in 50 CFR Part 17
Endangered and threatened species, Exports, Imports, Reporting and
recordkeeping requirements, Transportation.
Regulation Promulgation
Accordingly, we amend part 17, subchapter B of chapter I, title 50
of the Code of Federal Regulations, as set forth below:
PART 17--[AMENDED]
0
1. The authority citation for part 17 continues to read as follows:
Authority: 16 U.S.C. 1361-1407; 1531-1544; 4201-4245; unless
otherwise noted.
0
2. Amend Sec. 17.11(h), the List of Endangered and Threatened
Wildlife, as follows:
0
a. By adding an entry for ``Bat, Pacific sheath-tailed'' (Emballonura
semicaudata rotensis), in alphabetical order under MAMMALS, to read as
set forth below;
0
b. By adding an entry for ``Skink, Slevin's'' (Emoia slevini), in
alphabetical order under REPTILES, to read as set forth below;
0
c. By adding entries for ``Snail, fragile tree'' (Samoana fragilis),
``Snail, Guam tree'' (Partula radiolata), ``Snail, humped tree''
(Partula gibba), and ``Snail, Langford's tree'' (Partula langfordi), in
alphabetical order under SNAILS, to read as set forth below; and
[[Page 59496]]
0
d. By adding entries for ``Butterfly, Mariana eight-spot'' (Hypolimnas
octocula marianensis), ``Butterfly, Mariana wandering'' (Vagrans
egistina), and ``Damselfly, Rota blue'' (Ischnura luta), in
alphabetical order under INSECTS, to read as set forth below:
Sec. 17.11 Endangered and threatened wildlife.
* * * * *
(h) * * *
--------------------------------------------------------------------------------------------------------------------------------------------------------
Species Vertebrate
---------------------------------------------------------- population where When Critical Special
Historic range endangered or Status listed habitat rules
Common name Scientific name threatened
--------------------------------------------------------------------------------------------------------------------------------------------------------
Mammals
* * * * * * *
Bat, Pacific sheath-tailed Emballonura U.S. Territory of Entire.............. E 858 NA NA
(Mariana subspecies) (Payeyi, semicaudata rotensis. Guam, U.S. CNMI.
Paischeey).
* * * * * * *
Reptiles
* * * * * * *
Skink, Slevin's (Gualiik Emoia slevini........ U.S. Territory of Entire.............. E 858 NA NA
halumtanu, Gholuuf). Guam, U.S. CNMI.
* * * * * * *
Snails
* * * * * * *
Snail, fragile tree (Akaleha Samoana fragilis..... U.S. Territory of Entire.............. E 858 NA NA
dogas, Denden). Guam, U.S. CNMI.
Snail, Guam tree (Akaleha, Denden) Partula radiolata.... U.S. Territory of Entire.............. E 858 NA NA
Guam.
Snail, humped tree (Akaleha, Partula gibba........ U.S. Territory of Entire.............. E 858 NA NA
Denden). Guam, U.S. CNMI.
* * * * * * *
Snail, Langford's tree (Akaleha, Partula langfordi.... U.S. CNMI........... Entire.............. E 858 NA NA
Denden).
* * * * * * *
Insects
* * * * * * *
Butterfly, Mariana eight-spot Hypolimnas octocula U.S. Territory of Entire.............. E 858 NA NA
(Ababbang, Libweibwogh). marianensis. Guam, U.S. CNMI.
Butterfly, Mariana wandering Vagrans egistina..... U.S. Territory of Entire.............. E 858 NA NA
(Ababbang, Libweibwogh). Guam, U.S. CNMI.
* * * * * * *
Damselfly, Rota blue (Dulalas Ischnura luta........ U.S. CNMI........... Entire.............. E 858 NA NA
Luta, Dulalas Luuta).
* * * * * * *
--------------------------------------------------------------------------------------------------------------------------------------------------------
* * * * *
0
3. Amend Sec. 17.12(h), the List of Endangered and Threatened Plants,
as follows:
0
a. By adding entries for Bulbophyllum guamense, Cycas micronesica,
Dendrobium guamense, Eugenia bryanii, Hedyotis megalantha, Heritiera
longipetiolata, Maesa walkeri, Nervilia jacksoniae, Phyllanthus
saffordii, Psychotria malaspinae, Solanum guamense, Tabernaemontana
rotensis, Tinospora homosepala, and Tuberolabium guamense, in
alphabetical order under FLOWERING PLANTS, to read as set forth below:
Sec. 17.12 Endangered and threatened plants.
* * * * *
(h) * * *
[[Page 59497]]
--------------------------------------------------------------------------------------------------------------------------------------------------------
Species
---------------------------------------------------------- Historic range Family Status When Critical Special
Scientific name Common name listed habitat rules
--------------------------------------------------------------------------------------------------------------------------------------------------------
Flowering Plants
* * * * * * *
Bulbophyllum guamense............. Siboyas halumtanu, U.S. Territory of Orchidaceae......... T 858 NA NA
Siboyan halom tano. Guam, U.S. CNMI.
* * * * * * *
Cycas micronesica................. Fadang, Faadang...... U.S. Territory of Cycadaceae.......... T 858 NA NA
Guam, U.S. CNMI,
Federated States of
Micronesia,
Independent
Republic of Palau.
* * * * * * *
Dendrobium guamense............... None................. U.S. Territory of Orchidaceae......... T 858 NA NA
Guam, U.S. CNMI.
* * * * * * *
Eugenia bryanii................... None................. U.S. Territory of Myrtaceae........... E 858 NA NA
Guam.
* * * * * * *
Hedyotis megalantha............... Pau dedu, Pao doodu.. U.S. Territory of Rubiaceae........... E 858 NA NA
Guam.
* * * * * * *
Heritiera longipetiolata.......... Ufa halumtanu, Ufa U.S. Territory of Malvaceae........... E 858 NA NA
halom tano. Guam, U.S. CNMI.
* * * * * * *
Maesa walkeri..................... None................. U.S. Territory of Primulaceae......... T 858 NA NA
Guam, U.S. CNMI.
* * * * * * *
Nervilia jacksoniae............... None................. U.S. Territory of Orchidaceae......... T 858 NA NA
Guam, U.S. CNMI.
* * * * * * *
Phyllanthus saffordii............. None................. U.S. Territory of Phyllanthaceae...... E 858 NA NA
Guam.
* * * * * * *
Psychotria malaspinae............. Aplokating palaoan... U.S. Territory of Rubiaceae........... E 858 NA NA
Guam.
* * * * * * *
Solanum guamense.................. Biringenas halumtanu, U.S. Territory of Solanaceae.......... E 858 NA NA
Birengenas halom Guam, U.S. CNMI.
tano.
* * * * * * *
Tabernaemontana rotensis.......... None................. U.S. Territory of Apocynaceae......... T 858 NA NA
Guam, U.S. CNMI.
* * * * * * *
Tinospora homosepala.............. None................. U.S. Territory of Menispermaceae...... E 858 NA NA
Guam.
* * * * * * *
Tuberolabium guamense............. None................. U.S. Territory of Orchidaceae......... T 858 NA NA
Guam, U.S. CNMI.
* * * * * * *
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* * * * *
Dated: September 9, 2015.
Stephen Guertin,
Acting Director, U.S. Fish and Wildlife Service.
[FR Doc. 2015-24443 Filed 9-30-15; 8:45 am]
BILLING CODE 4310-55-P