[Federal Register Volume 80, Number 197 (Tuesday, October 13, 2015)]
[Proposed Rules]
[Pages 61568-61607]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2015-25298]
[[Page 61567]]
Vol. 80
Tuesday,
No. 197
October 13, 2015
Part II
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; Proposed Endangered
Status for Five Species From American Samoa; Proposed Rule
Federal Register / Vol. 80 , No. 197 / Tuesday, October 13, 2015 /
Proposed Rules
[[Page 61568]]
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DEPARTMENT OF THE INTERIOR
Fish and Wildlife Service
50 CFR Part 17
[Docket No. FWS-R1-ES-2015-0128; 4500030113]
RIN 1018-AZ97
Endangered and Threatened Wildlife and Plants; Proposed
Endangered Status for Five Species From American Samoa
AGENCY: Fish and Wildlife Service, Interior.
ACTION: Proposed rule.
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SUMMARY: We, the U.S. Fish and Wildlife Service (Service), propose to
list as endangered species two endemic American Samoan land snails, the
American Samoa distinct population segment of the friendly ground-dove,
the Pacific sheath-tailed bat, (South Pacific subspecies), and the mao,
under the Endangered Species Act (Act). If we finalize this rule as
proposed, it would extend the Act's protections to these species. The
effect of this regulation will be to add these species to the List of
Endangered and Threatened Wildlife.
DATES: We will accept comments received or postmarked on or before
December 14, 2015. Comments submitted electronically using the Federal
eRulemaking Portal (see ADDRESSES below) must be received by 11:59 p.m.
Eastern Time on the closing date. We must receive requests for public
hearings, in writing, at the address shown in FOR FURTHER INFORMATION
CONTACT by November 27, 2015.
ADDRESSES: You may submit comments by one of the following methods:
(1) Electronically: Go to the Federal eRulemaking Portal: http://www.regulations.gov. In the Search box, enter FWS-R1-ES-2015-0128,
which is the docket number for this rulemaking. Then, in the Search
panel on the left side of the screen, under the Document Type heading,
click on the Proposed Rules link to locate this document. You may
submit a comment by clicking on ``Comment Now!''
(2) By hard copy: Submit by U.S. mail or hand-delivery to: Public
Comments Processing, Attn: FWS-R1-ES-2015-0128; Division of Policy,
Performance, and Management Programs; U.S. Fish and Wildlife Service;
5275 Leesburg Pike, MS: BPHC; Falls Church, VA 22041.
We request that you send comments only by the methods described
above. We will post all comments on http://www.regulations.gov. This
generally means that we will post any personal information you provide
us (see Public Comments below for more information).
FOR FURTHER INFORMATION CONTACT: Mary Abrams, Field Supervisor, Pacific
Islands Fish and Wildlife Office, 300 Ala Moana Boulevard, Honolulu, HI
96850, by telephone 808-792-9400 or by facsimile 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 Act, if a species is
determined to be an endangered or threatened species throughout all or
a significant portion of its range, we are required to promptly publish
a proposal in the Federal Register and make a determination on our
proposal within 1 year. 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. Listing a species
as an endangered or threatened species and designations and revisions
of critical habitat can only be completed by issuing a rule. We intend
to publish a separate rule addressing designation of critical habitat
for the five species in American Samoa.
This rule proposes the listing of the two American Samoa land
snails, Eua zebrina (no common name) and Ostodes strigatus (no common
name), the American Samoa distinct population segment (DPS) of the
friendly ground-dove (Gallicolumba stairi), and two species from
American Samoa (extirpated), Western Polynesia, and Melanesia, the
Pacific sheath-tailed bat (South Pacific subspecies) (Emballonura
semicaudata semicaudata) and the mao (Gymnomyza samoensis) as
endangered species. These five species are candidate species for which
we have on file sufficient information on biological vulnerability and
threats to support preparation of a listing proposal, but for which
development of a listing regulation has been precluded by other higher
priority listing activities. This rule reassesses all available
information regarding status of and threats to these five species.
The basis for our action. Under the 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. One or more of the five candidate species face one
or more of the following threats:
Habitat loss and fragmentation or degradation due to
agriculture and urban development, nonnative ungulates, and nonnative
plants.
Collection for commercial purposes (snails only).
Predation by feral cats, rats, nonnative snails, and
nonnative flatworms.
Inadequate existing regulatory mechanisms.
Small numbers of individuals and populations.
Environmental effects from climate change are likely to exacerbate
these threats, and may become a threat to all five species in the
future.
We will seek peer review. We will seek comments from independent
specialists to ensure that our designation is based on scientifically
sound data, assumptions, and analyses in accordance with our joint
policy on peer review published in the Federal Register on July 1, 1994
(59 FR 34270). We will invite these peer reviewers to comment on our
listing proposal. Because we will consider all comments and information
received during the comment period, our final determinations may differ
from this proposal.
Information Requested
Public Comments
We intend that any final action resulting from this proposed rule
will be based on the best scientific and commercial data available and
be as accurate and as effective as possible. Therefore, we request
comments or information from the public, other concerned governmental
agencies, the American Samoa Government (ASG), the scientific
community, industry, or any other interested parties concerning this
proposed rule. For the Pacific sheath-tailed bat and the mao, we also
request comments or information from the CITES (Convention on
International Trade in Endangered Species of Wild Fauna and Flora)
management and scientific authorities or authority competent to issue
comparable documentation in the countries of Samoa, Fiji, Tonga, and
Vanuatu. We particularly seek comments concerning:
(1) The species' biology, range, and population trends, including:
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(a) Biological or ecological requirements of the species, including
habitat requirements for feeding, breeding, and sheltering;
(b) Genetics and taxonomy;
(c) Historical and current range including distribution patterns;
(d) Historical and current population levels, and current and
projected trends; and
(e) Past and ongoing conservation measures for these species, their
habitats, or both.
(2) Factors that that may affect the continued existence of these
species, which may include habitat modification or destruction,
overutilization, disease, predation, the inadequacy of existing
regulatory mechanisms, or other natural or manmade factors.
(3) Biological, commercial trade, or other relevant data concerning
any threats (or lack thereof) to these species and existing regulations
that may be addressing those threats.
(4) Empirical data or other scientific information describing the
specific impacts of climate change on the habitat, life history, and/or
ecology of these species, for example, the species' biological
response, or likely response, to changes in habitat resulting from
climate-change related changes in ambient temperature, precipitation,
drought, or storm severity.
(5) Additional information concerning the historical and current
status, ranges, distributions, and population sizes of these species,
including the locations of any additional populations of these species.
(6) Although we are not proposing to designate critical habitat at
this time, we request information about the quality and extent of areas
within U.S. jurisdiction (i.e., in American Samoa) that may qualify as
critical habitat for the proposed species. Specifically, we are
soliciting the identification of particular areas within the
geographical area occupied by these species in American Samoa that
include physical or biological features that are essential to the
conservation of these species and that may require special management
considerations or protection (16 U.S.C. 1532(5)(A)(i)). Essential
features may include, but are not limited to, features specific to
individual species' ranges, habitats, and life history characteristics
within the following general categories of habitat features: (1) Space
for individual growth and for normal behavior; (2) food, water, air,
light, minerals, or other nutritional or physiological requirements;
(3) cover or shelter; (4) sites for breeding, reproduction and
development of offspring; and (5) habitats that are protected from
disturbance or are representative of the historical, geographical, and
ecological distributions of the species (50 CFR 424.12(b)). Areas
outside the geographical area occupied by the species at the time of
listing should also be identified, if such areas are essential for the
conservation of the species (16 U.S.C. 1532(5)(A)(ii)). Unlike for
occupied habitat, such areas are not required to contain physical or
biological features essential to the conservation of the species. ESA
implementing regulations at 50 CFR 424.12(h) specify that critical
habitat shall not be designated within foreign countries or in other
areas outside of U.S. jurisdiction. Therefore, we request information
only on potential areas of critical habitat within locations under U.S.
jurisdiction.
Please include sufficient information with your submission (such as
scientific journal articles or other publications) to allow us to
verify any scientific or commercial information you include.
Please note that submissions merely stating support for or
opposition to the action under consideration without providing
supporting information, although noted, will not be considered in
making a determination, as section 4(b)(1)(A) of the Act directs that
determinations as to whether any species is a threatened or endangered
species must be made ``solely on the basis of the best scientific and
commercial data available.''
You may submit your comments and materials concerning this proposed
rule by one of the methods listed in the ADDRESSES section. We request
that you send comments only by the methods described in the ADDRESSES
section.
If you submit information via http://www.regulations.gov, your
entire submission--including any personal identifying information--will
be posted on the Web site. If your submission is made via a hardcopy
that includes personal identifying information, you may request at the
top of your document that we withhold this information from public
review. However, we cannot guarantee that we will be able to do so. We
will post all hardcopy submissions on http://www.regulations.gov.
Please include sufficient information with your comments to allow us to
verify any scientific or commercial information you include.
Comments and materials we receive, as well as supporting
documentation we used in preparing this proposed rule, will be
available for public inspection on http://www.regulations.gov, or by
appointment, during normal business hours, at the U.S. Fish and
Wildlife Service, Pacific Islands Fish and Wildlife Office (see FOR
FURTHER INFORMATION CONTACT).
Public Hearing
Section 4(b)(5) of the Act provides for one or more public hearings
on this proposal, if requested. Requests must be received within 45
days after the date of publication of this proposed rule in the Federal
Register. Such requests must be sent to the address shown in FOR
FURTHER INFORMATION CONTACT. We will schedule public hearings on this
proposal, if any are requested, and announce the dates, times, and
places of those hearings, as well as how to obtain reasonable
accommodations, in the Federal Register and local newspapers at least
15 days before the hearing.
Previous Federal Action
All five species proposed for listing are candidate species.
Candidate species are those taxa for which the Service has sufficient
information on their biological status and threats to propose them for
listing under the Act, but for which the development of a listing
regulation has been precluded to date by other higher priority listing
activities. The species addressed in this proposed rule are the Pacific
sheath-tailed bat, the mao, the American Samoa DPS of the friendly
ground-dove, and two American Samoa land snails, Eua zebrina and
Ostodes strigatus. The candidate status of all of these species was
most recently assessed and reaffirmed in the December 4, 2014, Review
of Native Species That Are Candidates for Listing as Endangered or
Threatened (CNOR) (79 FR 72450).
On May 4, 2004, the Center for Biological Diversity petitioned the
Secretary of the Interior to list 225 species of plants and animals,
including four of the five candidate species listed above, as
endangered or threatened under the provisions of the Act. Since then,
we have published our annual findings on the May 4, 2004, petition
(including our findings on the candidate species listed above) in the
CNORs dated May 11, 2005 (70 FR 24870), September 12, 2006 (71 FR
53756), December 6, 2007 (72 FR 69034), December 10, 2008 (73 FR
75176), November 9, 2009 (74 FR 57804), November 10, 2010 (75 FR
69222), October 26, 2011 (76 FR 66370), November 21, 2012 (77 FR
69994), November 22, 2013 (78 FR 70104), and December 4, 2014 (79 FR
72450). This proposed rule constitutes a further response to the 2004
petition.
In 2014, the Service evaluated the status and threats for the fifth
candidate species, the mao. We determined that
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this species warranted listing as an endangered or threatened species
under the Act and assigned a Listing Priority Number of 2 for this
species (79 FR 72450, December 4, 2014).
Background
Species Addressed in This Proposed Rule
The table below (Table 1) provides the common name, scientific
name, listing priority, and range for the species that are the subjects
of this proposed rule.
Table 1--Species Addressed in This Proposed Rule
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Listing
Common name Samoan name or other local Scientific name priority Range evaluated for
name number listing
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MAMMALS
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Pacific sheath-tailed bat (South Pacific Emballonura, semicaudata, 3 American Samoa, Fiji,
subspecies), Beka beka, Peapea vai, semicaudata. Samoa, Tonga, Vanuatu.
Tagiti.
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BIRDS
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Mao..................................... Gymnomyza samoensis....... 2 American Samoa, Samoa.
Friendly (shy) ground-dove, Tuaimeo..... Gallicolumba stairi....... 9 American Samoa DPS.
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SNAILS
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No common name.......................... Eua zebrina............... 2 American Samoa.
No common name.......................... Ostodes strigatus......... 2 American Samoa.
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The Samoan Archipelago
The Samoan Archipelago consists of a remote chain of 13 islands and
2 atolls in the Pacific Ocean south of the equator. These islands
extend more than 298 miles (mi) (480 kilometers (km)) in an east-west
orientation between 13 and 15 degrees south latitude, and 168 to 172
degrees west longitude (Goldin 2002, p. 4). The islands date to the
early Pleistocene and were formed as hot-spot shield volcanoes, with
the older islands located on the western end of the chain (Thornberry-
Ehrlich 2008, pp. 16, 28). The archipelago is divided into two
political entities, American Samoa, an unincorporated territory of the
United States, and the independent nation of Samoa (Craig 2009, p. 5).
American Samoa consists of five high islands and two atolls: Tutuila
(the largest island; 54 square (sq) mi (140 sq km)); Aunuu (1 sq mi (2
sq km)) off the southeast end of Tutuila; Ofu and Olosega (3.5 sq mi (9
sq km)) separated by a narrow channel now spanned by a bridge; Tau (15
sq mi (39 sq km)); Rose Atoll (1.5 sq mi (4 sq km)), a National
Wildlife Refuge) with two uninhabited islands, Rose and Sand; and
Swains Island (0.6 sq mi (1.5 sq km)), which is politically part of
American Samoa, but geologically and biologically part of the Tokelau
archipelago (Goldin 2002, pp. 5-6). These islands and atolls range in
elevation from the high peak of Mt. Lata on Tau at 3,170 ft (966 meters
(m)) to 4 to 6 ft (1 to 2 m) above sea level (asl) at Rose Atoll.
American Samoa lies within the tropics, where it is hot, humid, and
rainy year-round. The wet season is from October to May, with a
slightly cooler and drier season from June through September.
Temperatures average about 81.5 degrees Fahrenheit (F) (27 degrees
Celsius (C)). Rainfall averages 125 inches (in) (318 centimeters (cm))
annually at lower elevations, but can vary greatly depending upon
topography, reaching 300 in (750 cm) or greater annually in the
mountain areas. Hurricanes are a common natural disturbance in the
Samoan Archipelago, and occur at intervals of 1 to 13 years (Goldin
2002, p. 7).
In 2010, the population of American Samoa totaled 55,519
individuals (U.S. Census 2011, in litt.). Because of the steep
topography, most areas of the northern coastline of Tutuila are
uninhabited, and most people live on the narrow coastal plain on the
southern shore, within several hundred yards of the shoreline. The
islanders practice extensive small-scale agriculture on plots inland of
villages and in lowland rainforest on slopes that sometimes exceed 45
degrees (Atkinson and Medeiros 2006, p. 4). Before the arrival of
Polynesians approximately 3,000 years ago, the whole archipelago,
except for recent lava flows or poorly drained areas, was likely
covered by rain forest or cloud forest (Mueller-Dombois and Fosberg
1998, p. 360).
Samoa
The independent nation of Samoa (Samoa) is located less than 100 mi
(160 km) west of Tutuila Island, American Samoa, and consists of two
large inhabited islands, Upolu (424 sq mi (1,100 sq km)) and Savaii
(703 sq mi (1,820 sq km)), and 8 small offshore islets, several of
which are inhabited. Samoa lies between 13 to 14 degrees south latitude
and 170 to 173 degrees west longitude and has a total land area of
approximately 1,133 sq mi (2,934 sq km)) (Watling 2001, p. 26). The
highest point in Samoa is Mt. Silisili on Savaii at 6,093 ft (1,857 m)
asl. As discussed above, the Samoan archipelago is volcanic in origin
with the islands sequentially formed in a generally eastern direction
by a series of ``hot spot'' eruptions, starting with Savaii
approximately at 2 million years of age (Keating 1992, p. 131).
Kingdom of Tonga
The Kingdom of Tonga (Tonga) is located in the western South
Pacific Ocean, approximately 560 mi (900 km) southwest of the Tutuila
Island, American Samoa. The archipelago is spread over 500 mi (800 km)
in a north-south direction between 15 to 23.5 degrees south latitude
and 173 to 177 west degrees longitude (Australian Bureau of Meteorology
(BOM) and Commonwealth Scientific and Industrial Research Organization
(CSIRO) Australian BOM and CSIRO 2011, Vol. 2, p. 217). Tonga consists
of four groups of islands: Tongatapu and Eua in the south, Haapai in
the middle, Vavau in the north, and Niaufoou and Niua Toputapu in the
far north. The 172 named islands have an area of 289 sq mi (748 sq km).
The islands include high volcanic islands (maximum elevation 3,389 ft
(1,033 m) asl), elevated limestone islands and low-lying
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coralline islands (Australian BOM and CSIRO 2011, Vol. 2, p. 217).
Republic of Fiji
The Republic of Fiji (Fiji) is located in the western South Pacific
Ocean approximately 777 mi (1250 km) west of Tutuila Island, American
Samoa, between 16 to 20 degrees south latitude and 177 degrees east to
178 degrees west longitude. Fiji consists of 322 islands (105
inhabited) and a total land area of 7,078 sq mi (18,333 sq km) (Watling
2001, p. 22). The two largest islands, Viti Levu (4,026 sq mi (10,429
sq km)) and Vanua Levu (2,145 sq mi (5,556 sq km)), account for 87
percent of the total land area and are mountainous and of volcanic
origin with peaks up to 4,265 ft (1,300 m) asl (Australian BOM and
CSIRO 2011, Vol. 2, p. 77). The other islands consist of small volcanic
islands, low-lying atolls, and elevated reefs in the Northern and
Southern Lau groups in the east, the centrally located Lomaiviti group,
and the Yasawa group in the northwest (Watling 2001, p. 23).
Republic of Vanuatu
The Republic of Vanuatu (Vanuatu) is an archipelago located in the
western South Pacific Ocean, approximately 1,500 mi (2,400 km) west of
Tutuila Island, American Samoa. Vanuatu lies between 13 to 21 south
degrees latitude and 166 to 171 degrees east longitude and includes
over 80 islands (about 65 of which are inhabited) with a total land
area of 4,707 sq mi (12,190 sq km) (Central Intelligence Agency (CIA)
2013). Larger islands in general are characterized by rugged volcanic
peaks and tropical rainforests. The largest island is Espiritu Santo
(1,527 sq mi (3,955 sq km)), which also contains the highest peak,
Mount Tabwemasana (6,158 ft (1,877 m) asl) (Australia BOM and CSIRO
2011, Vol. 2, p. 245).
Territory of the Wallis and Futuna Islands
The Territory of the Wallis and Futuna Islands (Wallis and Futuna)
is an overseas territory of France located approximately 496 mi (799
km) west of Tutuila Island, American Samoa. Wallis and Futuna consists
of three main islands (Wallis or Uvea, Futuna, and Alofi) and more than
20 smaller islands, which lie between 13 to 14 south degrees latitude
and 176 to 178 west degrees longitude (Watling 2001, pp. 36-37). The
land area totals approximately 98 sq mi (255 sq km). Uvea is a low
volcanic island with gentle relief, while Futuna and Alofi
(uninhabited) are rugged mountainous islands with uplifted coral tiers
(Dupon and Beaudou 1986, p. 1; Watling 2001, p. 36). The islands have
experienced extensive deforestation due to the continued use of wood as
the main fuel source (CIA 2009).
Pacific Sheath-Tailed Bat (South Pacific Subspecies), Emballonura
semicaudata ssp. semicaudata, Peapea Vai (American Samoa), Tagiti
(Samoa), Beka Beka (Fiji)
The Pacific sheath-tailed bat is a member of the Emballonuridae, an
Old World bat family that has an extensive distribution primarily in
the tropics (Nowak 1994, pp. 90-91). A Samoan specimen was first
described by Peale in 1848 as Vespertilio semicaudatus (Lyon and Osgood
1909, p. 259). The species was later included in the genus Emballonura
(Temminck 1838; cited in the Integrated Taxonomic Information System
(ITIS) 2014) and is now known as Emballonura semicaudata (Smithsonian
Institution 1909; Tate and Archbold 1939, p. 8). This species is a
small bat. Males have a forearm length of about 1.8 in (45 millimeters
(mm)), and weigh approximately 0.2 ounces (oz) (5.5 grams (g)), and
females are slightly larger in size and weight (Lemke 1986, p. 744;
Nowak 1994, p. 91; Flannery 1995, p. 326; Uyehara and Wiles 2009, p.
5). The Pacific sheath-tailed bat was once common and widespread in
Polynesia, eastern Melanesia, and Micronesia and is the only
insectivorous bat recorded from a large part of this area (Hutson et
al. 2001, p. 138). Sheath-tailed bats are rich brown to dark brown
above and paler below (Walker and Paradiso 1983, p. 211). The common
name ``sheath-tailed bat'' refers to the nature of the tail attachment:
The tail pierces the tail membrane, and its tip appears completely free
on the upper surface of the membrane (Walker and Paradiso 1983, p.
209). The Pacific sheath-tailed bat (all subspecies) is listed as
Endangered in the 2015 IUCN (International Union for Conservation of
Nature) Red List (Bonaccorso and Allison 2008). Endangered is IUCN's
second most severe category of extinction assessment, which equates to
a very high risk of extinction in the wild. IUCN criteria include the
rate of decline, population size, area of geographic distribution, and
degree of population and distribution fragmentation; however, IUCN
rankings do not confer any actual protection or management.
Four subspecies of Pacific sheath-tailed bats are currently
recognized: E. s. rotensis, endemic to the Mariana Islands (Guam and
the Commonwealth of the Northern Mariana Islands; proposed for listing
as endangered in 2014 (79 FR 59363, October 1, 2014)), and referred to
here as the Mariana subspecies); E. s. sulcata in Chuuk and Pohnpei; E.
s. palauensis in Palau; and E. s. semicaudata in American Samoa, Samoa,
Tonga, Fiji, and Vanuatu (Koopman 1997, pp. 358-360; Oyler-McCance et
al. 2013, pp. 1,030-1,036), referred to here as the South Pacific
subspecies. Recent analysis found notable genetic differences between
E. s. rotensis, E. s. palauensis, and E. s. semicaudata, indeed greater
differences than typically reported between mammalian subspecies
(Oyler-McCance et al. 2013, p. 1,030). Hereafter, ``bat'' or ``Pacific
sheath-tailed bat'' refers to the South Pacific subspecies unless
otherwise noted.
All subspecies of the Pacific sheath-tailed bat appear to be cave-
dependent, roosting during the day in a wide range of cave types,
including overhanging cliffs, crevices, lava tubes, and limestone caves
(Grant 1993, p. 51; Grant et al. 1994, pp. 134-135; Hutson et al. 2001,
p. 139; Palmeirim et al. 2005, p. 28). Large roosting colonies appear
fairly common in the Palau subspecies, but smaller aggregations may be
more typical of at least the Mariana subspecies and perhaps other
species of Emballonura (Wiles et al. 1997, pp. 221-222; Wiles and
Worthington 2002, pp. 15, 17). The Mariana subspecies, which persists
only on the island of Aguiguan (Commonwealth of the Northern Mariana
Islands (CNMI)), appears to prefer relatively large caves (Wiles et al.
2009, p. 15 in O'Shea and Valdez 2009). The limestone cave ecosystem of
the Mariana subspecies on Aguiguan is characterized by constant
temperature, high relative humidity, and no major air movement (O'Shea
and Valdez 2009, pp. 77-78). Such basic habitat data are lacking for
the South Pacific subspecies of Pacific sheath-tailed bat, but may be
important because the alteration of climate conditions has been
implicated in the abandonment of roost caves by other bat species
(Hutson et al. 2001, p. 101). All subspecies of the Pacific sheath-
tailed bat are nocturnal and typically emerge around dusk to forage on
flying insects (Hutson et al. 2001, p. 138; Craig et al. 1993, p. 51).
The Mariana Islands subspecies forages almost entirely in forests
(native and nonnative) near their roosting caves (Esselstyn et al.
2004, p. 307). Other subspecies in Micronesia have been observed
foraging beneath the canopy of dense native forest (on Pohnpei) and
over town streets (Palau and Chuuk) (Bruner and Pratt 1979, p. 3). Bats
and swiftlets (Aerodramus spp.) are
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commonly found sharing caves (Lemke 1986, p. 744; Hutson et al. 2001,
p. 139; Tarburton 2002, p. 106; Wiles and Worthington 2002, p. 7,
Palmeirim et al. 2005, p. 28).
In American Samoa, Amerson et al. (1982, p. 74) estimated a total
population of approximately 11,000 Pacific sheath-tailed bats in 1975
and 1976. A precipitous decline of the bat on the island of Tutuila has
been documented since 1990 (Grant et al. 1994, p. 134; Koopman and
Steadman 1995, pp. 9-10; Helgen and Flannery 2002, pp. 4-5). Knowles
(1988, p. 65) recorded about 200 in 1988, and in 1993, observers caught
one bat and saw only three more (Grant et al. 1994, p. 134). A single
bat was also observed on two occasions in a small cave north of Alao
(Grant et al. 1994, pp. 134-135). Additional small caves and lava tubes
have been checked for bats and swiftlets, however, Tutuila is entirely
volcanic and does not have the extensive limestone cave systems that
provide bat roosting habitat in the Mariana Islands and other Pacific
island groups (Grant et al. 1994, p. 135). Two individuals were last
observed in the cave at Anapeapea Cove on the north shore of Tutuila in
1998 (Hutson et al. 2001, p. 138). Surveys conducted by the DMWR in
2006 failed to detect the presence of this species (DMWR 2006, p. 53).
In an attempt to ascertain whether the species is still extant, DMWR
conducted surveys consisting of acoustic sweeps and cave checks on all
main islands in 2008 and 2012, and no bats were detected (Fraser et al.
2009, p. 9; U.R. Tulafono 2011, in litt.; DMWR 2013, in litt.). Based
on its decline and the lack of detections since it was last seen in
1998, this species is thought to be nearly extirpated (if not already
extirpated) in American Samoa (DMWR 2006, p. 54; Uyehara and Wiles
2009, p. 5). DMWR continues to conduct acoustic surveys in search of
the Pacific sheath-tailed bat in American Samoa (Miles 2015a, in
litt.).
In Samoa, the Pacific sheath-tailed bat is known from the two main
islands of Upolu and Savaii, but the species has experienced a severe
decline over the last several decades, and has been observed only
rarely since Cyclones Ofa (1990) and Val (1991) (Lovegrove et al. 1992,
p. 30; Park et al. 1992, p. 47; Tarburton 2002, pp. 105-108). This
species was previously abundant on Upolu with an individual cave
estimated to support several thousand individuals (Ollier et al. 1979,
pp. 22, 39). A survey of 41 lava tube caves and other locations on
Upolu and Savaii conducted from 1994 to 1997 detected a total of 5
individuals at two sites, which had declined to 2 individuals total by
the end of the survey (Hutson 2001, p. 139; Tarburton 2002, pp. 105-
108, Tarburton 2011, p. 38). In Samoa, the Pacific sheath-tailed bat
occupies sea caves and lava tubes located from the coast up to
elevations of 2,500 ft (762 m) that range from 49 ft (15 m) to over
2,130 ft (650 m) in length; vary in height and width, number of
openings, and degree of branching; and may be subject to rockfalls and
flooding during high rain events (Tarburton 2011, pp. 40-49).
In Tonga, the distribution of the Pacific sheath-tailed bat is not
well known. It has been recorded on the island of Eua and Niaufoou
(Rinke 1991, p. 134; Koopman and Steadman 1995, p. 7), and is probably
absent from Ata and Late (Rinke 1991, pp. 132-133). In 2007, ten nights
of acoustic surveys on Tongatapu and Eua failed to record any
detections of this species (M. Pennay pers. comm. in Scanlon et al.
2013, p. 456). Pennay describes Eua as the place most likely to support
the Pacific sheath-tailed bat because of the island's large tracts of
primary forest and many rocky outcrops and caves, but he considers the
bat to be extremely rare or extirpated from both islands (M. Pennay
pers. comm. in Scanlon et al. 2013, p. 456).
In Fiji, the Pacific sheath-tailed bat is distributed throughout
the archipelago, on large islands such as Vanua Levu and Taveuni,
medium-sized islands in the Lau group (Lakeba, Nayau, Cicia, Vanua
Balavu), and small islets such as Yaqeta in the Yasawa group and Vatu
Vara and Aiwa in the Lau group (Palmeirim et al. 2005, pp. 31-32).
Pacific sheath-tailed bats in Fiji roost in lava tubes and limestone
caves of varying length and width, beneath rock outcrops, and in cave-
like areas formed by irregularly-shaped boulders located in areas along
the coast and up to 6.2 mi (10 km) inland (Palmierim et al. 2007, pp.
1-13). Running water or pools of water are a common occurrence in
inland caves with streams running through or coastal caves that are
tidally influenced (Palmierim et al. 2007, pp. 1-13). Habitat
surrounding roost sites includes undisturbed forest, secondary forest,
cultivated areas, and forested cliffs (Palmierim et al. 2007, pp. 1-
13). The species was reported as common some decades ago on the small,
volcanic island of Rotuma, a Fijian dependency, approximately 372 mi
(600 km) from the Fiji archipelago (Clunie 1985, pp. 154-155). Although
widely distributed, the species clearly has suffered a serious decline
since the 1950s as evidenced by a contraction of its range and a
decline in density and abundance on the islands where it still occurs
(Flannery 1995, p. 327; Palmeirim et al. 2005, p. 31). In 2000 to 2001
bats were absent or present in diminished numbers in many of the caves
known previously to be occupied on 30 Fijian islands, and villagers
reported that small bats, presumably Pacific sheath-tailed bats, were
no longer commonly seen (Palmeirim et al. 2005, p. 31).
The species is predicted to be extirpated or nearly so on Kadavu,
Vanua Levu, and Fiji's largest island, Viti Levu, where it was known to
be widespread until the 1970s (Palmeirim et al. 2005, p. 31; Scanlon et
al. 2013, p. 453). Field observations during the 2000 to 2001 surveys
documented a single large colony of several hundred individuals on
Yaqeta Island in the Yasawa group and a large colony on Vatu Vara
Island in the Lau group, but otherwise only a few to dozens of
individuals scattered among caves on small and remote islands in the
Lau group (Palmeirim et al. 2005, pp. 55-62). Scanlon et al. 2013 (p.
453) revisited the large cave colony on Yaqeta between 2007 and 2011
and described it as without any evidence of any recent use by bats
(e.g., odor, fresh guano) and probably abandoned. The loss of the
Yaqeta colony and the species' overall declining trend across the
archipelago led Scanlon et al. 2013 (p. 456) to infer a reduction in
population size of greater than 80 percent over the last 10 years. The
most important remaining sites for the protection of this species are
likely those on small and mid-sized islands in Lau where bats still
occur (Palmeirim et al. 2007, p. 512).
In Vanuatu, the Pacific sheath-tailed bat is known from two museum
specimens, one collected in 1929 and one collected before 1878, both on
the main island of Espiritu Santo (Helgen and Flannery 2002, pp. 210-
211). No subsequent expeditions have recorded sheath-tailed bats,
suggesting that this species was either extirpated or perhaps never
actually occurred in Vanuatu (Medway and Marshall 1975, pp. 32-33; Hill
1983, pp. 140-142; Flannery 1995, p. 326; Helgen and Flannery 2002, pp.
210-211; Palmeirim et al. 2007, p. 517). For example, Medway and
Marshall (1975, p. 453) detected seven other small, insectivorous bats
(family Microchiroptera) in Vanuatu, but failed to observe the Pacific
sheath-tailed bat, possibly as a result of survey sites and methods.
However, the Vanuatu provenance of the two specimens is not in question
(Helgen and Flannery 2002, p. 211). The current disjunct distribution
of the Pacific sheath-tailed bat (all subspecies) is suggestive of
[[Page 61573]]
extinctions (Flannery 1995, p. 45), and the possible extirpation of the
South Pacific subspecies from Vanuatu could be an example of this
(Helgen and Flannery 2002, p. 211). The bat's status in Vanuatu is
unknown, and a basic inventory of Vanuatu's bat fauna is lacking
(Helgen and Flannery 2002, p. 211).
In summary, the Pacific sheath-tailed bat, once widely distributed
across the southwest Pacific islands of American Samoa, Samoa, Tonga,
and Fiji, has undergone a significant decline in numbers and
contraction of its range. Reports of possible extirpation or extremely
low numbers in American Samoa and Samoa, steep population declines in
Fiji, and the lack of detections in Tonga and Vanuatu, suggest that the
Pacific sheath-tailed bat is vulnerable to extinction throughout its
range. The remaining populations of the Pacific sheath-tailed bat
continue to experience habitat loss from deforestation and development,
predation by introduced mammals, and human disturbance of roosting
caves, all of which are likely to be exacerbated in the future by the
effects of climate change (see Summary of Factors Affecting the Species
discussion below). In addition, low population numbers and the
breakdown of the metapopulation equilibrium across its range render the
remaining populations of Pacific sheath-tailed bat more vulnerable to
chance occurrences such as hurricanes.
Summary of Factors Affecting the Pacific Sheath-Tailed Bat
A. The Present or Threatened Destruction, Modification, or Curtailment
of Its Habitat or Range
Habitat Destruction and Modification by Deforestation
Deforestation can cause the destruction and modification of
foraging habitat of the Pacific sheath-tailed bat as a result of the
loss of cover and reduction of available insect prey. The loss of
native plant diversity associated with the conversion of native forests
to agriculture and other uses can result in a corresponding reduction
in the diversity and number of flying insects (Hespenheide 1975, pp.
84, 96; Waugh and Hails 1983, p. 212; Tarburton 2002, p. 107).
Deforestation results from logging, agriculture, and development
(Government of Samoa 2001, p. 59; Wiles and Worthington 2002, p. 18)
and from hurricanes. Based on the preference of the Mariana subspecies
for foraging in forested habitats near their roost caves, Wiles et al.
(2011, p. 307) predict that past deforestation in the Mariana
archipelago may be a principal factor in limiting their current
population to the island of Aguiguan, which has healthy native forest.
Similarly, in Fiji, most sheath-tailed bat colonies are found roosting
in caves in or near good forest (e.g., closed canopy, native forest)
(Palmeirim et al. 2005, pp. 36, 44); however, much of it has been lost
on the large Fijian islands (Palmeirim et al. 2007, p. 515).
Deforestation has been extensive and is ongoing across the range of
the Pacific sheath-tailed bat. On the island of Tutuila, American
Samoa, agriculture and development cover approximately 24 percent of
the island and are concentrated in the coastal plain and low-elevation
areas where loss of forest is likely to have modified foraging habitat
for sheath-tailed bats (American Samoa Community College (ASCC) 2010,
p. 13). In Samoa, the amount of forested area declined from 74 to 46
percent of total land area between 1954 and 1990 (Food and Agricultural
Organization (FAO) 2005 in litt.). Between 1978 and 1990, 20 percent of
all forest losses in Samoa were attributable to logging, with 97
percent of the logging having occurred on Savaii (Government of Samoa
1998 in Whistler 2002, p. 132). Forested land area in Samoa continued
to decline at a rate of roughly 2.1 percent or 7,400 ac (3,000 ha)
annually from 1990 to 2000 (FAO 2005 in litt.). As a result, there is
very little undisturbed, mature forest left in Samoa (Watling 2001, p.
175; FAO 2005 in litt.). Today, only 360 ac (146 ha) of native lowland
rainforests (below 2,000 ft or 600 m) remain on Savaii and Upolu as a
result of logging, agricultural clearing, residential clearing
(including relocation due to tsunami), and natural causes such as
rising sea level and hurricanes (Ministry of Natural Resources and
Environment (MNRE) 2013, p. 47). On Upolu, direct or indirect human
influence has caused extensive damage to native forest habitat (above
2,000 ft or 600 m) (MNRE 2013, p. 13). Although forested, almost all
upland forests on Upolu are largely dominated by introduced species
today. Savaii still has extensive upland forests, which are for the
most part undisturbed and composed of native species (MNRE 2013, p.
40). Although the large Fijian islands still have some areas of native
forest, much of it has been lost (e.g., 17 percent between 1990 and
2000; FAO 2005 in litt.), and commercial logging continues (Palmeirim
et al. 2007, p. 515). The best available information does not provide
the current status of native forests and rates of forest loss in Tonga
or Vanuatu. Native forests are preferred foraging habitat of the
Pacific sheath-tailed bat, and deforestation is occurring in Fiji
(where the last relatively large population occurs), and in Samoa, and
has occurred in American Samoa. Therefore we conclude that habitat
destruction and modification by deforestation is a current threat to
the species in at least Fiji and Samoa, which comprise roughly 62
percent of the land area, and occupy the center, of the bat's range.
Habitat Destruction and Modification by the Effects of Climate Change
Climate change may have impacts to the habitat of the Pacific
sheath-tailed bat. Discussion of these impacts is included in our
complete discussion of climate change in the section ``E. Other Natural
or Manmade Factors Affecting Their Continued Existence,'' below.
Conservation Efforts To Reduce Habitat Destruction, Modification, or
Curtailment of Its Range
American Samoa
The National Park of American Samoa (NPSA) was established to
preserve and protect the tropical forest and archaeological and
cultural resources, to maintain the habitat of flying foxes, to
preserve the ecological balance of the Samoan tropical forest, and,
consistent with the preservation of these resources, to provide for the
enjoyment of the unique resources of the Samoan tropical forest by
visitors from around the world (Pub. L. 100-571, Pub. L. 100-336).
Under a 50-year lease agreement between local villages, the American
Samoa Government, and the Federal Government, approximately 8,000 ac
(3,240 ha) of forested habitat on the islands of Tutuila, Tau, and Ofu
are protected and managed, including suitable foraging habitat for the
Pacific sheath-tailed bat (NPSA Lease Agreement 1993).
Samoa
As of 2014, a total of approximately 58,176 ac (23,543 ha), roughly
8 percent of the total land area of Samoa (285,000 ha) was enlisted in
terrestrial protected areas, with the majority located in five national
parks covering a total of 50,629 ac (20,489 ha), overlapping several
sites known to be previously occupied by the bat (Tarburton 2002, pp.
105-107; Tarburton 2011, pp. 43-46).
Fiji
Fiji currently has 23 terrestrial protected areas covering 188 sq
mi (488 sq km) or 2.7 percent of the nation's land area (Fiji
Department of Environment 2014, pp. 20-21). Most notably, on Taveuni
Island, the Bouma
[[Page 61574]]
National Heritage Park (3,500 ac (1,417 ha)), Taveuni Forest Reserve
(27,577 ac (11,160 ha)), and Ravilevu Reserve (9.934 ac (4,020 ha)) may
contain caves and could provide important foraging habitat for the
Pacific sheath-tailed bat (Fiji Department of Environment 2011;
Naikatini 2015, in litt.; Scanlon 2015a, in litt.). Additional areas of
remnant forest and important bat habitat are also managed informally
under traditional custodial management systems (Scanlon 2015a, in
litt.).
Summary of Factor A
Based on our review of the best available scientific and commercial
information, habitat destruction and degradation by deforestation, as a
result of logging and land-clearing for agriculture and other land-
uses, is occurring throughout the range of the Pacific sheath-tailed
bat. Habitat destruction and modification and range curtailment are
current threats to the Pacific sheath-tailed bat that are likely to
persist in the future.
B. Overutilization for Commercial, Recreational, Scientific, or
Educational Purposes
The best available information does not indicate that the Pacific
sheath-tailed bat is used for any commercial, recreational, scientific,
or educational purpose. As a result, we do not find overutilization for
commercial, recreational, scientific, or educational purposes to be a
threat to the Pacific sheath-tailed bat.
C. Disease or Predation
Predation by Nonnative Mammals
Predation by nonnative mammals (mammals that occur as a result of
introduction by humans) is a factor in the decline of the Pacific
sheath-tailed bat throughout its range. Terrestrial predators may be
able to take the bat directly from its roosts, which are often in
exposed sites such as shallow caves, rock overhangs or cave entrances.
Domestic and feral cats (Felis catus) can capture low-flying bats; cats
have been documented to wait for bats as they emerge from caves and
capture them in flight (Tuttle 1977 in Palmeirim et al. 2005, p. 33;
Ransome 1990 in Palmeirim et al. 2005, p. 33; Woods et al. 2003, pp.
178, 188). Consequently, even a few cats can have a major impact on a
population of cave-dwelling bats (Palmeirim et al. 2005, p. 34).
Of the predators introduced to Fiji, cats are the most likely to
prey on bats (Palmeirim et al. 2005, pp. 33-34). On Cicia Island in the
Lau group in Fiji, Palmeirim et al. (2005, p. 34) observed a cat next
to the entrance of a cave where Pacific sheath-tailed bats roosted, far
from any human settlement. On Lakeba (Lau), a cave that once harbored a
large colony of Pacific sheath-tailed bats is now empty and called Qara
ni Pusi (cave of the cat; (Palmeirim et al. 2005, p. 34)). Feral cats
are also present on Tutuila and on the Manua Islands in American Samoa,
(Freifeld 2007, pers. comm.; Arcilla 2015, in litt.). Feral cats have
also been documented in Samoa, Tonga, and are likely present in Vanuatu
(Atkinson and Atkinson 2000, p. 32; Freifeld 2007, pers. comm.; Arcilla
2015, in litt.).
Rats may also prey on the Pacific sheath-tailed bat. Rats are
omnivores and opportunistic feeders and 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; Global Invasive Species Database (GISD) 2011). Rats are known
to prey on non-volant (young that have not developed the ability to
fly) bats at roosting sites and can be a major threat to bat colonies
(Wiles et al. 2011, p. 306). Of several nonnative rats (Rattus spp.)
found on islands in the Pacific, black rats (R. rattus) likely pose the
greatest threat to Pacific sheath-tailed bats because of their
excellent climbing abilities (Palmeirim 2015, in litt.). Although we
lack direct evidence of black rats preying on Pacific sheath-tailed
bats, this rat species has had documented, adverse impacts to other
colonial species of small bats, such as Townsend's big-eared bat
(Corynorhinus townsendii) in California (Fellers 2000, pp. 524-525),
and several species (Mystacina spp.) in New Zealand (Daniel and
Williams 1984, p. 20). Based on observations of swiftlets, cave-nesting
birds that often share bats' roosting caves, smooth rock overhangs in
tall caverns can provide nesting surfaces safe from rats, cats, and
other predators (Tarburton 2011, p. 38). However, bats roosting in
caves with low ledges or those that are filled with debris as a result
of rockfalls or severe weather events are likely to either abandon such
caves or become more accessible to predators such as rats. Rats have
been postulated as a problem for the Mariana subspecies of the Pacific
sheath-tailed bat (Wiles et al. 2011, p. 306); their remaining roost
sites on Aguiguan appear to be those that are inaccessible to rodents
(Wiles and Worthington 2002, p. 18; Berger et al. 2005, p. 144).
Nonnative rats are present throughout the range of Pacific sheath-
tailed bats (Atkinson and Atkinson 2000, p. 32), and although we lack
information about the impact of rats on this species, based on
information from other bat species, we consider rats to be predators of
this species.
In summary, nonnative mammalian predators such as rats and feral
cats are present throughout the range of the Pacific sheath-tailed bat.
Predation of related subspecies and other cave-roosting bats by rats
and feral cats strongly suggests a high probability of predation of the
Pacific sheath-tailed bat. Based on the above information, we conclude
that predation by rats and feral cats is a current and future threat to
the Pacific sheath-tailed bat throughout its range.
Disease
Disease may contribute to the decline of the Pacific sheath-tailed
bat, especially because of the bat's communal roosting habit (Wiles and
Worthington 2002, p. 13). Microchiropterans have been severely affected
by certain diseases, such as white nose syndrome in North America;
therefore, the possibility exists that an undetected disease has led or
contributed to the extirpation of this species on several islands
(Malotaux 2012a in litt.). However, disease has not been observed
either in the Mariana or South Pacific subspecies of Pacific sheath-
tailed bat (Palmeirim et al. 2007, p. 517; Wiles et al. 2011, p. 306).
The best available information does not indicate that disease is a
threat to this species; therefore, we conclude that disease is not a
current threat the Pacific sheath-tailed bat or likely to become a
threat in the future.
Conservation Efforts To Reduce Disease or Predation
We are unaware of any conservation actions planned or implemented
at this time to abate the threats of predation by feral cats or rats to
the Pacific sheath-tailed bat.
Summary of Factor C
In summary, based on the best available scientific and commercial
information, we consider predation by nonnative mammals to be an
ongoing threat to the Pacific sheath-tailed bat that will continue into
the future. We do not find that disease is a threat to the Pacific
sheath-tailed bat, or that it is likely to become one in the future.
D. The Inadequacy of Existing Regulatory Mechanisms
The Act requires that the Secretary assess available regulatory
mechanisms in order to determine whether existing regulatory mechanisms
may be inadequate as designed to address
[[Page 61575]]
threats to the species being evaluated (Factor D). Under this factor,
we examine whether existing regulatory mechanisms are inadequate to
address the potential threats to the Pacific sheath-tailed bat
discussed under other factors. In determining whether the inadequacy of
regulatory mechanisms constitutes a threat to the Pacific sheath-tailed
bat, we analyzed the existing Federal, Territorial, and international
laws and regulations that may address the threats to this species or
contain relevant protective measures. Regulatory mechanisms, if they
exist, may preclude the need for listing if we determine that such
mechanisms adequately address the threats to the species such that
listing is not warranted.
American Samoa
In American Samoa no existing Federal laws, treaties, or
regulations specify protection of the Pacific sheath-tailed bat's
foraging habitat from the threats of agriculture and development,
protect its known roosting caves from disturbance, or address the
threat of predation by nonnative mammals such as rats and feral cats.
However, some existing Territorial laws and regulations have the
potential to afford the species some protection but their
implementation does not achieve that result. The DMWR is given
statutory authority to ``manage, protect, preserve, and perpetuate
marine and wildlife resources'' and to promulgate rules and regulations
to this end (American Samoa Code Annotated (ASCA), title 24, chapter
3). This agency conducts monitoring surveys, conservation activities,
and community outreach and education about conservation concerns.
However, to our knowledge, DMWR has not used this authority to
undertake conservation efforts for the Pacific sheath-tailed bat such
as habitat protection and control of nonnative predators (DMWR 2006,
pp. 79-80).
The Territorial Endangered Species Act provides for appointment of
a Commission with the authority to nominate species as either
endangered or threatened (ASCA, title 24, chapter 7). Regulations
adopted under the Coastal Management Act (ASCA Sec. 24.0501 et seq.)
also prohibit the taking of threatened or endangered species listed as
threatened or endangered by the American Samoa Government (ASG)
(American Samoa Administrative Code (ASAC) Sec. 26.0220.I.c). However,
the ASG has not listed the bat as threatened or endangered so these
regulatory mechanisms do not provide protection for this species.
Commercial hunting and exportation of the Pacific sheath-tailed bat
is prohibited under ASCA, title 24, chapter 23, ``Conservation of
Flying Foxes),'' which also authorizes and directs the ASG DMWR to
monitor flying fox populations, protect roosting areas from
disturbance, and conduct other activities to manage and protect the
species. This law identifies the Pacific sheath-tailed bat as a
``flying fox species'' (ASCA Sec. 24.2302), but it has not led to
measures implemented to protect the Pacific sheath-tailed bat or its
habitat from known threats. The sale and purchase of all native bats is
prohibited, and the take, attempt to take, and hunting of all native
bats are prohibited unless explicitly allowed during an officially
proclaimed hunting season (ASAC Sec. 24.1106); take is defined as
harass, harm, pursue, hunt, shoot, wound, kill, trap, capture, or
collect or to attempt to engage in such conduct (ASAC Sec. 24.1101
(f)). However, we do not consider hunting or other forms of utilization
to be a threat to the Pacific sheath-tailed bat.
Under a 50-year lease agreement between local villages, the
American Samoa Government, and the Federal Government, approximately
8,000 ac (3,240 ha) of forested habitat on the islands of Tutuila, Tau,
and Ofu are protected and managed in the National Park of American
Samoa (NPSA Lease Agreement 1993). There is the potential for
development surrounding park in-holdings, but such forest clearing
would be isolated and small in scale compared to the large tracts of
forested areas protected.
Under ASCA, title 24, chapter 08 (Noxious Weeds), the Territorial
DOA has the authority to ban, confiscate, and destroy species of plants
harmful to the agricultural economy. This authority was expanded by
executive regulation so that the governor can ban the use or
importation of any plant (ASCA Sec. 24.0801). A permit from the
director of the DOA is likewise required before plants may be imported
to American Samoa (ASAC Sec. 24.0328). These regulations are
promulgated without consultation with the DMWR (DMWR 2006, p. 80).
Although these regulations provide some protection against the
introduction of nonnative plant species, some imports permitted by the
DOA, or that escape detection, could prove harmful to native species
and their habitats in American Samoa. These regulations do not require
any measures to control invasive nonnative plants that already are
established and proving harmful to native species and their habitats.
Similarly, under ASCA, title 24, chapter 06 (Quarantine), the
director of DOA has the authority to promulgate agriculture quarantine
restrictions concerning animals. Using this authority, the DOA has
restricted the importation of insects, farm animals, and ``domestic
pets,'' including exotic animals, to entry by permit only (See ASAC
Sec. 24.0305 et. seq.). Yet these restrictions do not expressly extend
to all non-domesticated animals, nor does the DMWR have any
consultative role in restricting entry of animals (or plants) harmful
to wildlife or native flora. Accordingly, existing statutes and
regulations leave a great deal of discretion to the DOA, which may not
block the entry of animals harmful to native species or their habitats
(DMWR 2006, p. 80). These regulations do not require any measures to
control nonnative animals, such as mammalian predators, that already
are established and proving harmful to native species and their
habitats.
The Territorial Coastal Management Act establishes a land use
permit (LUP) system for development projects and a Project Notification
Review System (PNRS) for multi-agency review and approval of LUP
applications (ASAC Sec. 26.0206). The standards and criteria for
review of LUP applications includes requirements to protect Special
Management Areas (SMA), Unique Areas, and ``critical habitats'' where
``sustaining the natural characteristics is important or essential to
the productivity of plant and animal species, especially those that are
threatened or endangered'' on all lands and in coastal waters in the
territory not under federal management authority (ASCA Sec. 24.0501
et. seq.). To date, three SMAs have been designated (Pago Pago Harbor,
Leone Pala, and Nuuuli Pala; ASAC Sec. 26.0221), and all are in
coastal and mangrove habitats on the south shore of Tutuila that likely
provide little foraging habitat and no roosting habitat for the Pacific
sheath-tailed bat. The only Unique Area designated to date is the
Ottoville Rainforest (American Samoa Coastal Management Program 2011,
p. 52), also on Tutuila's south shore, which hypothetically may provide
some foraging habitat for Pacific sheath-tailed bats, but it is a
relatively small island of native forest in the middle of the heavily
developed Tafuna Plain (Trail 1993, p. 4), far from the last known
roost sites of this species. To the best of our knowledge, no critical
habitats, as defined in the ASCA, have been designated. Nonetheless,
these laws and regulations are designed to ensure that ``environmental
concerns
[[Page 61576]]
are given appropriate consideration,'' and include provisions and
requirements that could address to some degree threats to native
forests and other habitats important to the Pacific sheath-tailed bat,
even though individual species are not named (ASAC Sec. 26.0202 et
seq.). Because the implementation of these regulations has been
minimal, and because review of permits is not rigorous and does not
reliably include the members of the PNRS Board responsible for
management of wildlife and natural resources (ASCA Sec. 26.026.C),
issuance of permits may not provide the habitat protection necessary
for the conservation of the species and instead may result in loss of
native habitat important to the Pacific sheath-tailed bat and other
species as a result of land clearing for agriculture and development
(DMWR 2006, p. 71). We conclude that the implementation of the Coastal
Management Act and its PNRS is inadequate to address the threat of
habitat destruction and degradation to the Pacific sheath-tailed bat.
In summary, some existing Territorial laws and regulatory
mechanisms have the potential to offer some level of protection for the
Pacific sheath-tailed bat and its habitat but are not currently
implemented in a manner that would do so. The DMWR has not has not
exercised its statutory authority to address threats to the bat such
has nonnative species. The bat is not listed pursuant to the
Territorial Endangered Species Act. The Coastal Management Act and its
implementing regulations have the potential to address this threat more
substantively, but are inadequately implemented. Therefore, we conclude
that regulatory mechanisms in American Samoa do not address threats to
the Pacific sheath-tailed bat.
Samoa
In Samoa, the Animals Ordinance 1960 and the Protection of Wildlife
Regulations 2004 regulate the protection, conservation, and utilization
of terrestrial or land-dwelling species (MNRE and the Secretariat of
the Pacific Regional Environment Programme (SPREP) 2012, p. 5). These
laws and regulations prohibit, and establish penalties for committing,
the following activities: (1) The take, keep, or kill of protected and
partially protected animal species; (2) harm of flying species endemic
to Samoa; and (3) the export of any bird from Samoa (MNRE and SPREP
2012, pp. 5-6). As described above, the Pacific sheath-tailed bat is
neither endemic to the Samoan archipelago, nor is it listed as a
``flying species endemic to Samoa'' under the Protection of Wildlife
Regulations 2004. Therefore, it is not protected by the current
regulations.
The Planning and Urban Management Act 2004 (PUMA) and PUMA
Environmental Impact Assessment (EIA) Regulation (2007) were enacted to
ensure all development initiatives are properly evaluated for adverse
environmental impacts (MNRE 2013, p. 93). The information required
under PUMA for Sustainable Management Plans (Para. 18, Consultation)
and Environmental Impact Assessments (Para. 46, Matters the Agency
shall consider) does not include specific consideration for species or
their habitat (PUMA 2004, as amended). Other similar approval
frameworks mandated under other legislation address specific stressors
and activities. These include the permit system under the Lands Surveys
and Environment Act 1989 for sand mining and coastal reclamation, and
ground water exploration and abstraction permits under the Water
Resources Act 2008 (MNRE 2013, p. 93). The PUMA process has been
gaining in acceptance and use; however, information is lacking on its
effectiveness in preventing adverse impacts to species or their
habitats (MNRE 2013, p. 93).
The Forestry Management Act 2011 aims to provide for the effective
and sustainable management and utilization of forest resources. This
law creates the requirement for a permit or license for commercial
logging or harvesting of native, agro-forestry, or plantation forest
resources (MNRE and SPREP 2012, p. 18). Permitted and licensed
activities must follow approved Codes of Practice, forestry harvesting
plans, and other requirements set by the Ministry of Natural Resources
and Environment. Certain restrictions apply to actions on protected
lands such as national parks and reserves. Permits or licenses may
designate certain areas for the protection of the biodiversity,
endangered species, implementation of international conventions, water
resources, or area determined to be of significance on which no
forestry activities may be undertaken (Forestry Management Act 2011,
Para. 57). Although this law includes these general considerations for
managing forest resources, it does not specifically provide protection
to habitat for the Pacific sheath-tailed bat.
Fiji
In Fiji, the Endangered and Protected Species Act (2002) regulates
the international trade, domestic trade, possession, and transportation
of species protected under CITES and other species identified as
threatened or endangered under this act. Under the law, the Pacific
sheath-tailed bat is recognized as an ``indigenous species not listed
under CITES.'' Its recognition under the law can garner public
recognition of the importance of conserving the bat and its habitat
(Tuiwawa 2015, in litt.); however, because the focus of the legislation
is the regulation of foreign and domestic trade, and the bat is not a
species in trade, this law is not intended to provide protection for
the bat or its habitat within Fiji. The best available information does
not identify any laws or regulations protecting the habitat of the
Pacific sheath-tailed bat in Fiji.
Tonga
In Tonga, the Birds and Fish Preservation (Amendment) Act 1989, is
a law to ``make provision for the preservation of wild birds and
fish.'' The law protects birds and fish, and provides for the
establishment of protected areas, but it does not specifically protect
the Pacific sheath-tailed bat or its habitat (Kingdom of Tonga 1988,
1989).
Vanuatu
In Vanuatu, the Environment Management and Conservation Act (2002)
provides for conservation, sustainable development, and management of
the environment of Vanuatu. Areas of the law that may apply to species
protection are the Environmental Impact Assessment process, which
includes an assessment of protected, rare, threatened, or endangered
species or their habitats in project areas, laws on bioprospecting, and
the creation of Community Conservation Areas for the management of
unique genetic, cultural, geological, or biological resources
(Environmental Management and Conservation Act, Part 3, Environmental
Impact Assessment). The Wild Bird Protection law (Republic of Vanuatu
2006) is limited to birds and does not offer protection to the Pacific
sheath-tailed bat or its habitat.
Summary of Factor D
Based on the best available information, some existing regulatory
mechanisms have the potential to offer protection, but their
implementation does not reduce or remove threats to the Pacific sheath-
tailed bat. In American Samoa the DMWR has not exercised its statutory
authority to address threats to the bat such as predation by nonnative
species, the bat is not listed pursuant to the Territorial Endangered
Species Act, and the Coastal Management Act's land use permitting
process is implemented inadequately to reduce or remove the threat of
habitat destruction or
[[Page 61577]]
modification to the Pacific sheath-tailed bat. Therefore, we conclude
that existing regulatory mechanisms do not address the threats to the
Pacific sheath-tailed bat.
E. Other Natural or Manmade Factors Affecting Its Continued Existence
Roost Disturbance
Disturbance of roosting caves has contributed to the decline of the
Pacific sheath-tailed bat throughout its range. Disturbance of roost
caves by humans is likely to have occurred as a result of recreation,
harvesting of co-occurring bat species, and, more commonly, guano
mining (Grant et al. 1994, p. 135; Tarburton 2002, p. 106; Wiles and
Worthington 2002, p. 17; Palmeirim et al. 2005, pp. 63, 66; Malotaux
2012a in litt.; Malotaux 2012b in litt.). Roost disturbance is a well-
known problem for many cave-dwelling species (Palmeirim et al. 2005, p.
3). Roosts are important sites for bats for mating, rearing young, and
hibernating (in mid- and high-latitude species). Roosts often
facilitate complex social interactions, offer protection from inclement
weather, help bats conserve energy, and minimize some predation risk
(Kunz and Lumsden 2003, p. 3); therefore, disturbance at caves and
being repeatedly flushed from their roosts may cause bats to incur
elevated energetic costs and other physiological stress and potentially
increased risk of predation while in flight. Roost disturbance thus
would negatively affect the survival and reproduction of the Pacific
sheath-tailed bat.
In American Samoa, human disturbance at the two caves known to be
historical roost sites for the bat is likely to be minimal. Guano
mining occurred in the Anapeapea caves in the 1960s (Amerson et al.
1982, p. 74), but ceased due to the high salt content as a result of
flooding with seawater during cyclones (Grant et al. 1994, p. 135). On
Taveuni, Fiji, a cave known to be used as a roosting cave for the
Pacific sheath-tailed bat is under more immediate threat by humans, as
the cave is situated close to farmland, and is often used by locals
(Malotaux 2012a, p. 3). On Upolu, Samoa, caves previously known to
support bats are well-known and often visited by tourists; one within O
le Pupu Pue National Park and others on village land (Tarburton 2011,
pp. 40, 44). Swiftlets (Aerodramus spp.) are still observed in
significant numbers in these caves (Tarburton 2011, p. 40), but these
birds may be more tolerant than bats of human disturbance. We do not
have information on human disturbance of roosts in Tonga or Vanuatu.
Goats are certain to enter caves for shelter from the sun and
consequently can disturb roosting bats, although the extent of this
disturbance is unknown (Scanlon 2015b, in litt.). Feral goats have been
observed entering caves on Aguiguan Island for shelter, which disrupts
colonies of the endangered swiftlet and is believed to disturb the
Mariana subspecies of the Pacific sheath-tailed bat (Wiles and
Worthington 2002, p. 17; Cruz et al. 2008, p. 243; Scanlon 2015b, in
litt.). Researchers found that if caves that were otherwise suitable
for bats were occupied by goats, there were no bats present in the
caves (Guam Division of Aquatic and Wildlife Resources 1995, p. 95). On
Yaqeta Island, Fiji, a cave once known to support several hundred
Pacific sheath-tailed bats but now abandoned, is located within a small
forest fragment frequented by goats (Scanlon et al. 2013, p. 453).
Populations of the Pacific sheath-tailed bat are concentrated in
the caves where they roost, and chronic disturbance of these sites can
result in the loss of populations, as described above. Because so few
populations of this bat remain, loss of additional populations to roost
disturbance further erodes its diminished abundance and distribution.
Based on the above information, roost disturbance at caves accessible
to humans and animals such as feral goats is a current threat and will
likely continue to be a threat into the future.
Pesticides
The use of pesticides may negatively affect the Pacific sheath-
tailed bat as a result of direct toxicity and a reduction in the
availability of insect prey. Pesticides are known to adversely affect
bat populations, either by secondary poisoning when bats consume
contaminated insects or by reducing the availability of insect prey
(Hutson et al., 2001, p. 138; Mickleburgh et al. 2002, p. 19).
Pesticides may have contributed to declines and loss of the Mariana
subspecies of Pacific sheath-tailed bat on islands where pesticides
were once applied in great quantities (Guam, Saipan, and Tinian) (Wiles
and Worthington 2002, p. 17).
In American Samoa and Samoa, current levels of pesticide use are
likely lower than several decades ago when their use, particularly
during the years in which taro was grown on large scales for export
(1975-1985), coincided with the decline of bats in both places and has
been implicated as the cause (Tarburton 2002, p. 107). However, Grant
et al. (1994, pp. 135-136) dismissed the role of insecticides in the
decline of the bat in American Samoa based on the absence of a similar
population crash in the insectivorous white-rumped swiftlet (Aerodramus
spodiopygius) and the limited use of agricultural and mosquito-control
pesticides. On the island of Taveuni in Fiji, where bat populations
have persisted at low levels over the last 10 years (Palmeirim et al.
2005, p. 62, Malotaux 2012, in litt.), several locals reported that
pesticide use was quite widespread, and their use may be similar on
other Fijian islands (Malotaux 2012, in litt.). We do not have
information about pesticide use in Tonga or Vanuatu. The best available
information does not lead us to conclude that the use of pesticides is
a current threat to the Pacific sheath-tailed bat or that it is likely
to become one in the future.
Hurricanes
Although severe storms are a natural disturbance with which the
Pacific sheath-tailed bat has coexisted for millennia, such storms
exacerbate other threats to the species by adversely affecting habitat
and food resources and pose a particular threat to its small and
isolated remaining populations. American Samoa, Samoa, Fiji, Tonga, and
Vanuatu are irregularly affected by hurricanes (Australian BOM and
CSIRO 2011 Vol. 1, p. 41). Located in the Southern Hemisphere, these
countries experience most hurricanes during the November to April wet
season, with the maximum occurrence between January and March
(Australian BOM and CSIRO 2011 Vol. 1, p. 47). In the 41-year period
ending in 2010, more than 280 hurricanes passed within 250 mi (400 km)
of Samoa (52 storms), Tonga (71), Fiji (70), and Vanuatu (94)
(Australian BOM and CSIRO 2011, pp. 76, 186, 216, 244). In recent
decades, several major (named) storms have hit American Samoa and Samoa
(Tusi in 1987, Ofa in 1990, Val in 1991, Heta in 2004, and Olaf in 2005
(MNRE 2013, pp. 31-32; Federal Emergency Management Agency 2015, in
litt.)); Tonga (Waka in 2001 and Ian in 2014 (Tonga Meteorological
Service 2006, in litt.; World Bank 2014, in litt.)); Fiji (Tomas in
2010 (Digital Journal 2010, in litt.)); and, most recently, Vanuatu
(Pam in 2015 (BBC 2015, in litt.)).
The high winds, waves, strong storm surges, high rainfall, and
flooding associated with hurricanes, particularly severe hurricanes
(with sustained winds of at least 150 mi per hour or 65 m per second)
cause direct mortality of the Pacific sheath-tailed bat. Cyclones Ofa
(1990) and Val (1991) removed the dense vegetation that had obscured
the
[[Page 61578]]
entrance to the larger cave at Anapeapea Cove, inundated the cave with
water, filled it with coral and fallen trees, and washed the cave walls
clean (Craig et al. 1993, p. 52; Grant et al. 1994, p. 135). The
majority of sheath-tailed bats in the cave likely were killed when the
hurricane hit (Grant et al. 1994, p. 135).
Hurricanes also cause direct mortality of the Pacific sheath-tailed
bat as a result of the bats' inability to forage during extended
periods of high wind or rain, during which they may starve. Cyclone Val
(December 1991) remained stationary over the Samoan archipelago for
four days, and Pacific sheath-tailed bats likely were unable to feed
during this time (Grant et al. 1994, p. 135). Despite the ability of
Pacific sheath-tailed bats to enter torpor to survive episodes of
inclement weather, the high ambient temperatures in Samoa may preclude
the energy savings necessary to sustain a small (4-7-g) torpid bat for
an extended period (Grant et al. 1994, p. 135).
Hurricanes may also cause modification of the roosting habitat of
the Pacific sheath-tailed bat by modifying vegetation in and around
cave entrances and altering climate conditions within roosting caves as
a result. Microchiropterans, such as the Pacific sheath-tailed bat, can
spend over half their lives in their roosts; consequently, the
microclimate of these habitats can exert a strong influence over their
heat-energy balance (Campbell et al. 2011, p. 174). The presence of
nearby forest cover and a well-developed tree canopy at cave entrances
is likely to be important in maintaining temperature and relative
humidity, and minimizing air movement in bat roosts, while allowing for
passage. O'Shea and Valdez (2009, pp. 77-78) characterized the
limestone cave ecosystem of the Mariana subspecies on Aguiguan as
having constant temperature, high relative humidity, and no major air
movement. Although such data are lacking for the Pacific sheath-tailed
bat, alteration of climate conditions has been implicated in the
abandonment of roost caves by other bat species (Hutson et al. 2001, p.
101).
Loss of forest cover and associated insect prey for bats as a
result of hurricanes can reduce foraging opportunities. Following
Cyclones Ofa (1990) and Val (1991), about 90 percent of the forests on
Upolu and Savaii were blown over or defoliated (Park et al. 1992, p. 4;
Elmqvist et al. 2002, pp. 385, 388). Tarburton (2002, p. 107) noted
that the abundance of flying insects remained low for weeks after
cyclones had defoliated trees. Although the Pacific sheath-tailed bat
has the capacity to forage in a variety of habitats, a study of habitat
use by the Mariana subspecies showed a clear preference for forested
habitats (Esselstyn et al. 2004, p. 307). Finally, the Pacific sheath-
tailed bat's severely diminished abundance and distribution increase
the likelihood that mortality events will cause population-level
impacts and increase the vulnerability of populations and of the
species to environmental catastrophes. Based on the information
described above, we consider hurricanes to be a factor that exacerbates
other threats to the Pacific sheath-tailed bat.
Low Numbers of Individuals and Populations
The low numbers of individuals and populations of this subspecies
place the Pacific sheath-tailed bat at great risk of extinction from
inbreeding and stochastic events such as storms. The threat is
significant for cave-dwelling species whose populations are often
highly localized with few numbers of animals that can easily be lost in
a severe storm, disease outbreak, or disturbance to the roost caves
(Wiles and Worthington 2002, p. 20).
Species that undergo significant habitat loss and degradation and
face other threats resulting in decline in numbers and range reduction
are inherently highly vulnerable to extinction resulting from localized
catastrophes such as severe storms or disease outbreaks, climate change
effects, and demographic stochasticity (Shaffer 1981, p. 131; Gilpin
and Soul[eacute] 1986, pp. 24-34; Pimm et al. 1988, p. 757; Mangel and
Tier 1994, p. 607). Conditions leading to this level of vulnerability
are easily reached by island species that face numerous threats such as
those described above. Small populations persisting in fragmented
habitat face increased risk from environmental catastrophes, such as
hurricanes, which could immediately extinguish some or all of the
remaining populations; demographic stochasticity that could leave the
species without sufficient males or females to be viable; or inbreeding
depression or loss of adaptive potential that can be associated with
loss of genetic diversity and result in eventual extinction (Shaffer
1981, p. 131; Lacy 2000, pp. 40, 44-46). The problems associated with
small population size and vulnerability to natural catastrophes or
random demographic or genetic fluctuations are further magnified by
synergistic interactions with ongoing threats such as those discussed
above under Factors A and C (Lacy 2000, pp. 45-47).
Breakdown of the Metapopulation Equilibrium
The Pacific sheath-tailed bat is thought to have a metapopulation
structure (Palmeirim et al. 2005, p. 29), and will only persist in an
archipelago if the island colonization rate is sufficiently high to
compensate for the rate of extirpation caused by stochastic factors on
individual islands (Palmeirim et al. 2005, p. 36). However, the
colonization rate is obviously proportional to the availability of
source populations; immigration of bats to recolonize sites or islands
where the species was extirpated is dependent on sufficient numbers of
animals existing in multiple other sites or islands within dispersal
distance (Hanski and Gilpin 1991, pp. 4-14). Consequently, the
extirpation of the Pacific sheath-tailed bat from some islands,
particularly from the largest islands, may in the long term result in
the permanent regional extinction of the species, even if suitable
environmental conditions persist on some islands (Palmeirim et al.
2005, p. 36). For example, the continued decline of the only
significant source population of Pacific sheath-tailed bat in the
Fijian archipelago greatly diminishes the probability of recolonization
and persistence throughout the remainder of its range in Fiji, where it
is currently considered to be extirpated or nearly extirpated. The loss
of a functioning metapopulation is a current threat and will continue
to be a threat in the future.
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 (IPCC 2013, p. 1,450). 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 (IPCC 2013, p. 1,450).
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
[[Page 61579]]
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 effects of climate
change and habitat fragmentation are the most menacing facet of climate
change for biodiversity (Hannah et al. 2005, p. 4). Currently, there
are no climate change studies that address impacts to the specific
habitat of the Pacific sheath-tailed bat. There are, however, climate
change studies that address potential changes in the tropical Pacific
on a broader scale.
In our analyses, we reference the scientific assessment and climate
change predictions for the western Pacific region prepared by the
Pacific Climate Change Science Program (PCCSP), a collaborative
research partnership between the Australian Government and 14 Pacific
Island countries, including Samoa, Tonga, Fiji, and Vanuatu (Australian
BOM and CSIRO 2011 Vol. 1, p. 15). The assessment builds on the Fourth
Assessment Report of the Intergovernmental Panel on Climate Change
(IPCC), and presents regional predictions for the area roughly between
25[deg] S. to 20[deg] N. and 120[deg] E. to 150[deg] W. (excluding the
Australian region south of 10[deg] S. and west of 155[deg] E.)
(Australian BOM and CSIRO 2011 Vol. 1, pp. 14, 20). The findings for
Samoa (13[deg] S. and 171[deg] E.) may be used as a proxy for American
Samoa (14[deg] S. and 170[deg] W.).
The annual average air temperatures and sea surface temperatures
are projected to increase in American Samoa, Samoa, Fiji, Tonga, and
Vanuatu, as well as throughout the western Pacific region (Australian
BOM and CSIRO 2011 Vol. 2, pp. 91, 198, 228, 258). The projected
regional warming is around 0.5-1.0 [deg]C by 2030, regardless of the
emissions scenario. By 2055, the warming is generally 1.0-1.5 [deg]C
with regional differences depending on the emissions scenario.
Projected changes associated with increases in temperature include, but
are not limited to, changes in mean precipitation with unpredictable
effects on local environments (including ecosystem processes such as
nutrient cycling), increased occurrence of drought cycles, increases in
the intensity and number of severe storms, sea-level rise, a shift in
vegetation zones upslope, and shifts in in the ranges and lifecycles of
individual species (Loope and Giambelluca 1998, pp. 514-515; Pounds et
al. 1999, pp. 611-612; IPCC AR4 2007, p. 48; 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; Sturrock et al. 2011, p. 144;
Townsend et al. 2011, pp. 14-15; Warren 2011, pp. 221-226; Finucane et
al. 2012, pp. 23-26; Keener et al. 2012, pp. 47-51).
In the western Pacific region, increased ambient temperatures is
projected to lead to increases in annual mean rainfall, the number of
heavy rain days (20-50 mm), and extreme rainfall events in American
Samoa, Samoa Fiji, Tonga, and Vanuatu (Australian BOM and CSIRO 2011
Vol. 1, p. 178; Australian BOM and CSIRO 2011 Vol. 2, pp. 87-88, 194-
195, 224-225, 254-255). Impacts of increased precipitation on the
Pacific sheath-tailed bat are unknown.
Hurricanes are projected to decrease in frequency in this part of
the Pacific but increase in severity as a result of global warming
(Australian BOM and CSIRO 2011 Vol. 2, pp. 88, 195, 225, 255). The high
winds, waves, strong storm surges, high rainfall, and flooding
associated with hurricanes, particularly severe hurricanes (with
sustained winds of 150 mi (240 km) per hour), have periodically caused
great damage to roosting habitat of Pacific sheath-tailed bats and to
native forests that provide their foraging habitat (Craig et al. 1993,
p. 52; Grant et al. 1994, p. 135; Tarburton 2002, pp. 105-108;
Palmeirim et al. 2005, p. 35), as described in the ``Hurricanes''
section, above.
In the western Pacific region, sea level is projected to rise 1.18
to 6.3 in (30 to 160 mm) by 2030, 2.6 to 12.2 in (70 to 310 mm) by
2055, and 8.3 in to 2 ft (210 to 620 mm) by 2090 under the high-
emissions scenario (Australian BOM and CSIRO 2011 Vol. 2, pp. 91, 198,
228, 258). The Pacific sheath-tailed bat is known to roost in areas
close to the coast and forage in the adjacent forested areas at or near
sea-level, as well as inland and at elevations up to 2,500 ft (762 m).
The impacts of projected sea-level rise on low-elevation and coastal
roosting and foraging habitat are likely to reduce and fragment the
bat's habitat on individual high islands.
In summary, although we lack information about the specific effects
of projected climate change on the Pacific sheath-tailed bat, we
anticipate that increased ambient temperature, precipitation, hurricane
intensity, and sea-level rise and inundation would create additional
stresses on the bat and on its roosting and foraging habitat because it
is vulnerable to these disturbances. The risk of extinction as a result
of the effects of climate change increases when a species' range and
habitat requirements are restricted, its habitat decreases, and its
numbers and number of populations decline (IPCC 2007, pp. 8-11). In
addition, the fragmented range, diminished number of populations, and
low total number of individuals have caused the Pacific sheath-tailed
bat to lose redundancy and resilience rangewide. Therefore, we would
expect the Pacific sheath-tailed bat to be particularly vulnerable to
the habitat impacts of projected environmental effects of climate
change (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). Based on the
above information, we conclude that habitat impacts resulting from the
effects of climate change are not a current threat but are likely to
become a threat to the Pacific sheath-tailed bat in the future.
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 of roost disturbance, low numbers,
hurricanes, or breakdown of the metapopulation equilibrium that
negatively impact the Pacific sheath-tailed bat.
Summary of Factor E
In summary, based on the best scientific and commercial information
available, we consider other natural and manmade factors to be current
and ongoing threats to the Pacific sheath-tailed bat. Roost
disturbance, small population size, and breakdown of the metapopulation
dynamic are threats to the Pacific sheath-tailed bat and are likely to
continue in the future. The bat's small and isolated remaining
populations are vulnerable to natural environmental catastrophes such
as hurricanes, and the threats of small population size and hurricanes
are likely to continue into the future. Due to reduced levels of
pesticide use and the uncertainty regarding impacts to this species, we
do not consider the use of pesticides to be a threat to the Pacific
sheath-tailed bat. Although we do not consider climate change to be a
current threat to the Pacific sheath-tailed bat, we anticipate that
climate change is likely to exacerbate other threats to the species and
to become a threat in the future.
Synergistic Effects
In our analysis of the five factors, we found that the Pacific
sheath-tailed bat is likely to be affected by loss of forest
[[Page 61580]]
habitat, predation by nonnative mammals, roost disturbance, and small
population size. We also identify several potential sources of risk to
the species (e.g., disease, pesticides, climate change) that we do not
currently consider to be significantly affecting the Pacific sheath-
tailed bat because of their low occurrence today or apparently minimal
overall impact on the species. Multiple stressors acting in combination
have greater potential to affect the Pacific sheath-tailed bat than
each factor alone. The combined effects of environmental, demographic,
and catastrophic-event stressors, especially on a small population can
lead to a decline that is unrecoverable and results in extinction
(Brook et al. 2008, pp. 457-458). The impacts of the stressors
described above, which might be sustained by a larger, more resilient
population, have the potential in combination to rapidly affect the
size, growth rate, and genetic integrity of a species that persists as
small, disjunct populations. Thus, factors that, by themselves, may not
have a significant effect on the Pacific sheath-tailed bat, may affect
the subspecies when considered in combination.
Proposed Determination for the Pacific Sheath-Tailed Bat
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 Pacific sheath-tailed bat. We find that the Pacific sheath-
tailed bat is presently in danger of extinction throughout its entire
range based on the severity and immediacy of the ongoing and projected
threats described above. Habitat loss and degradation due to
deforestation, predation by nonnative mammals, human disturbance of
roost caves, and stochastic events such as hurricanes, floods, or
disease outbreaks, which all pose a particular threat to the small and
isolated remaining populations and probable low total abundance
throughout its range, render the Pacific sheath-tailed bat in its
entirety highly susceptible to extinction as a consequence of these
imminent threats. The vulnerability of the species and its cave habitat
to the impacts of predation and human disturbance is exacerbated by
hurricanes and likely to be further exacerbated in the future by the
effects of climate change, such as sea level rise, extreme rain events,
and increased storm severity. The breakdown of the Pacific sheath-
tailed bat's metapopulation structure is expected to reduce
opportunities for repopulation following local extirpations of
dwindling populations due to stochastic events. In addition, the
continued decline of the last relatively large population of this
species in Fiji further diminishes the probability of persistence
throughout the remainder of its range where it is currently considered
to be extirpated or nearly extirpated. In addition, the continued
decline of the last relatively large population of this species in Fiji
further diminishes the probability of persistence throughout the
remainder of its range where it is currently considered to be
extirpated or nearly extirpated.
In summary, habitat destruction and modification from deforestation
is a threat to the Pacific sheath-tailed bat that is occurring
throughout its range (Factor A). The threat of predation by nonnative
predators such as rats and feral cats is ongoing (Factor C). Existing
regulatory mechanisms do not address the threats to the Pacific sheath-
tailed bat (Factor D). Human disturbance of roost caves, low numbers of
individuals and populations and their concomitant vulnerability to
catastrophic events such as hurricanes, and the breakdown of the
metapopulation structure all are current threats to the bat as well
(Factor E). All of these factors pose threats to the Pacific sheath-
tailed bat, whether we consider their effects individually or
cumulatively, and all of these threats will continue in the future.
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 the Pacific sheath-tailed
bat is presently in danger of extinction throughout its entire range
based on the severity and immediacy of threats currently impacting the
species. Therefore, On the basis of the best available scientific and
commercial information, we propose listing Pacific sheath-tailed bat as
endangered in accordance with sections 3(6) and 4(a)(1) of the Act.
Under the Act and our implementing regulations, a species may
warrant listing if it is in danger of extinction or likely to become so
throughout all or a significant portion of its range. Because we have
determined that the Pacific sheath-tailed bat is endangered throughout
all of its range, no portion of its range can be ``significant'' for
purposes of the definitions of ``endangered species'' 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, July 1, 2014).
Mao, Gymnomyza samoensis
The genus Gymnomyza refers to birds in the honeyeater family
Meliphagidae, which are restricted to a few islands in the southwestern
Pacific Ocean. The mao (Gymnomyza samoensis), also called maomao, is
one of three honeyeater species in the genus (Mayr 1945, p. 100). We
have carefully reviewed the available taxonomic information (Watling
2001, p. 174; BirdLife International 2013; Gill and Donsker 2015; ITIS
2015a) and have concluded the species is a valid taxon.
The mao is a large (approximately 11 in (28 cm)), ``very dark-
looking honeyeater . . . uniformly olive-black with a brown suffusion,
except for an olive stripe beneath the eye. The ``slender, down-curved
bill and feet are black'' (Watling 2001, p. 174). Butler and Stirnemann
(2013, p. 25) report that male mao have blue eyes and are larger, while
females are smaller with brown eyes. Juveniles have a shorter bill than
adults, and eye color changes 2 months post-fledging (Butler and
Stirnemann 2013, p. 25). The mao is a very vocal species and makes a
variety of loud distinctive calls with bouts of calling lasting up to a
minute (Watling 2001, p. 174). Calls differ between sexes (Butler and
Stirnemann 2013, p. 25).
The mao is endemic to the Samoan archipelago. The species was
thought to be primarily restricted to mature, well-developed, moist,
mossy forests at upper elevations (Watling 2001, p. 175; Engbring and
Ramsey 1989, p. 68), but has recently been observed at elevations
ranging from 932 to 5,075 ft (284 to 1,547 m) and in ecosystems
including lowland rainforest, disturbed secondary forest, and montane
rainforest (MNRE 2006, pp. 9-10). The birds use the mid- to upper-
canopy levels of the forest and
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will also forage along forest edges and brushy forest openings
(Engbring and Ramsey 1989, p. 68). The mao has also been recorded
visiting coconut trees near the coast (Watling 2001, p. 175).
Butler and Stirnemann (2013, p. 30) provide the following
information about the mao's habitat use. The birds only occur in
forested areas with a canopy layer, including modified habitat such as
plantations where large trees also are present. They do not occur in
logged areas with no large trees or canopy. Mao are primarily found in
the high canopy layer, but also spend considerable time foraging on the
trunks of trees and feeding on nectar sources near the ground (such as
ginger (family Zingiberaceae)) and in low bushes (such as Heliconia
spp.). The mao selects territories with high tree species diversity and
with appropriate nectar sources and a large tree from which the male
sings. Trees near a commonly used singing tree are selected for
nesting. No particular tree species is used for nesting, but all nests
are built more than 5 meters above the ground.
Butler and Stirnemann (2013, pp. 19-32) provide the following
information about mao life history and breeding behavior. Based on a
study of 15 nests, the mao nests once a year, between June and October,
and produces one egg per clutch (Butler and Stirnemann 2013, pp. 19-
32). The nest consists of young branches of various trees and contains
little lining (Butler and Stirnemann 2013, p. 25). Incubation lasts 19
days, and chicks fledge 21-22 days after hatching. Juveniles are
dependent on adults for approximately 8 to 10 weeks post-fledging. The
female is almost exclusively responsible for incubation and feeding the
chick, and both adults defend the nest. The mao will re-nest if the
first nest fails, but not if the first nesting attempt produces a
chick. Pairs are highly territorial with high site fidelity.
The mao's diet consists primarily of nectar, and also includes some
invertebrates and fruit (MNRE 2006, p. 11). Nectar is an especially
important food source during the breeding season, and the mao will
defend nectar patches (Butler and Stirnemann 2013, p. 30). The mao eats
invertebrates by probing dead material and moss, and by gleaning from
emerging leaves (Butler and Stirnemann 2013, p. 30). Females forage for
invertebrates under dead leaves on the forest floor to feed their
fledglings (Butler and Stirnemann 2013, p. 30). Fledglings solicit food
from the female by begging continually from the forest floor (Butler
and Stirnemann 2013, p. 28).
The mao was once found throughout Savaii and Upolu (Samoa) likely
in forests ranging from the coast to mountain tops (MNRE 2006, p. 2).
It is endemic to the islands of Savaii and Upolu, Samoa, and Tutuila
Island, American Samoa (Engbring and Ramsey 1989, p. 68; Watling 2001,
p. 174). The mao was observed during an 1839 expedition on Tutuila
(Amerson et al. 1982, p. 72), two male specimens were collected there
in 1924, and an unconfirmed observation of the mao on Tutuila was
reported in 1977 (Engbring and Ramsey 1989, p. 68; Watling 2001, p.
174).
The mao is currently found only on the islands of Savaii and Upolu
in Samoa (Amerson et al. 1982, p. 72; Engbring and Ramsey 1989, p. 68;
Watling 2001, p. 74; MNRE 2006, p. 2). In 1984, the mao was reported as
common in undisturbed upland forests (foothill, montane, and cloud
forests above 1,970 ft (600 m)) of Upolu and Savaii (Bellingham and
Davis 1988, p. 124). A decline in distribution was observed in the
1990s following a period in which several powerful hurricanes hit
Samoa: Tusi (1987), Ofa (1990), and Val (1991) (Lovegrove 1992, p. 26;
MNRE 2006, pp. 2, 4). Otherwise, no detailed surveys of the mao were
conducted before 2005, and little information exists regarding changes
in abundance and distribution (MNRE 2006, p. 2). Surveys conducted in
2005-2006 found mao at seven sites on Upolu and Savaii in upland
forested habitat, yielded a rough estimate of 500 individuals and
indicated that numbers are declining (MNRE 2006, p. 4; Tipamaa 2007, in
litt., cited in Birdlife International 2012). The Rapid Biodiversity
Assessment of Upland Savaii, Samoa conducted in 2012 detected small
numbers of the mao at two sites on the island (Atherton and Jefferies
2012, p. 14), and it is possible that the species has particular
habitat requirements that have become limited in Samoa (MNRE 2013, p.
12). Neither the 2012 surveys nor a study of the species' biology and
movements (Butler and Stirnemann 2013) yielded an updated population
estimate. However, researchers observed that the species is rarer than
previously thought and recommended that comprehensive surveys be
conducted to generate a new population estimate (Stirnemann 2015, in
litt).
The mao is likely extirpated from Tutuila Island in American Samoa
(Freifeld 1999, p. 1,208). Surveys conducted on Tutuila Island in 1982
and 1986 and from 1992 to 1996 did not detect the mao (Amerson et al.
1982, p. 72; Engbring and Ramsey 1989; p. 68; Freifeld 2015 in litt.).
Given that the species is noisy and conspicuous, it is unlikely that a
population on Tutuila was missed during the surveys (Engbring and
Ramsey 1989; p. 68). More recent surveys conducted by DMWR in forested
habitats likely to support mao failed to detect their presence, further
indicating the likelihood that the species no longer occurs on Tutuila
(MacDonald 2015 in litt.).
The mao is listed as Endangered in the 2014 IUCN Red List (Birdlife
International 2012). Endangered is IUCN's second most severe category
of extinction assessment, which equates to a very high risk of
extinction in the wild. IUCN criteria include the rate of decline,
population size, area of geographic distribution, and degree of
population and distribution fragmentation; however, IUCN rankings do
not confer any actual protection or management.
Summary of Factors Affecting the Mao
A. The Present or Threatened Destruction, Modification, or Curtailment
of Its Habitat or Range
Habitat Destruction and Modification by Deforestation
Several thousand years of subsistence agriculture and more recent
commercial agriculture has resulted in the alteration and great
reduction in area of forests at lower elevations in the Samoan
archipelago (Whistler 1994, p. 40; Mueller-Dombois and Fosberg 1998, p.
361; Whistler 2002, pp. 130-131). In American Samoa, forest clearing
for agriculture has contributed to habitat loss and degradation of
forests in the lowland areas on Tutuila, and has the potential to
spread into higher elevations and previously undisturbed forest;
however, owing to limits on the feasibility of land-clearing imposed by
the island's extreme topography, large areas of mature native
rainforest have persisted. Deforestation, therefore, is unlikely to
have been a cause of the mao's extirpation on this island in American
Samoa.
The loss of forested habitat in Samoa is a primary threat to the
mao (MNRE 2006, p. 5). Between 1954 and 1990, the amount of forested
area declined from 74 to 46 percent of total land area in Samoa (Food
and Agricultural Organization (FAO) 2005 in litt.). Between 1978 and
1990, 20 percent of all forest losses in Samoa were attributable to
logging, with 97 percent of the logging having occurred on Savaii
(Government of Samoa 1998 in Whistler 2002, p. 132). Forested land area
in Samoa continued to decline at a rate of
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roughly 2.1 percent or 7,400 ac (3,000 ha) annually from 1990 to 2000
(FAO 2005 in litt.). As a result, there is very little undisturbed,
mature forest left in Samoa (Watling 2001, p. 175; FAO 2005 in litt.).
The clearing of land for commercial agriculture has been the
leading cause of deforestation in Samoa--more so than plantations or
logging (Whistler 2002, p. 131). The transition from subsistence
agriculture to developing cash crops for export (e.g., taro, bananas,
cacao) coupled with rapid population growth and new technologies, led
to increased forest clearing in Samoa (Paulson 1994, pp. 326-332;
Whistler 2002, pp. 130-131). Today, only 360 ac (146 ha) of native
lowland rainforests (below 2,000 ft or 600 m) remain on Savaii and
Upolu as a result of logging, agricultural clearing, residential
clearing (including relocation due to tsunami), and natural causes such
as rising sea level and hurricanes (MNRE 2013, p. 47). On Upolu, direct
or indirect human influence has caused extensive damage to native
forest habitat above 2,000 ft (600 m) (MNRE 2013, p. 13). Although
forested, almost all upland forests on Upolu are largely dominated by
introduced species today (MNRE 2013, p. 12). Savaii still has extensive
upland forests which are for the most part undisturbed and composed of
native species (MNRE 2013, p. 40). However, forest clearance remains an
ongoing threat to the mao (MNRE 2006, p. 5). Logging is slowing down
because the most accessible forest has largely been removed, but is an
ongoing problem on Savaii despite years of effort to phase it out (MNRE
2006, p. 5; Atherton and Jeffries 2012, p. 17). Shifting or slash-and-
burn cultivation is an increasing concern in upland forest that
provides important refuges for the mao because farmers use forestry
roads from heavily logged lowland forests to gain access to formerly
inaccessible land (MNRE 2006, p. 5). For example, there is much concern
about potential forest loss because of road that has been bulldozed
into the cloud forest (above 3,280 ft (1,000 m)) on Savaii, apparently
illegally (Atherton and Jeffries 2012, p. 16). Such roads provide
vectors for invasive nonnative plant and animal species as well, thus
exacerbating those threats to the mao and its habitat (Atherton and
Jeffries 2012, p. 108).
Habitat quality has also degraded with the loss of closed forest
space (MNRE 2006, p. 5; Butler and Stirnemann 2013, p. 22). An analysis
in 1999 identified 32 percent of the total forest cover as ``open''
forest (less than 40 percent tree cover) and less than 0.05 percent as
``closed'' forest, largely as a result of damage from Cyclones Ofa and
Val (Butler and Stirnemann 2013, p. 22). An additional 24 percent of
the forest cover is classified as secondary re-growth forest. As a
result, the montane forest in Samoa is now extremely open and patchy
with fewer food resources for birds, including the mao (Butler and
Stirnemann 2013, p. 22). The montane forests are also increasingly
vulnerable to invasion by nonnative trees and other plants (Butler and
Stirnemann 2013, p. 22), which adversely affect native forests through
competition for light, nutrients, and water; chemical inhibition; and
prevention of reproduction. Loss of forest is likely to affect the mao
by reducing breeding, nesting, and foraging habitat, increasing forest
fragmentation, and increasing the abundance and diversity of invasive
species (Butler and Stirnemann 2013, p. 22).
On the island of Tutuila, American Samoa, agriculture and urban
development covers approximately 24 percent of the island, and up to 60
percent of the island contains slopes of less than 30 percent where
additional land clearing is feasible (ASCC 2010, p. 13; DWMR 2006, p.
25). Farmers are increasingly encroaching into some of the steep
forested areas as a result of suitable flat lands already being
occupied with urban development and agriculture (ASCC 2010, p. 13).
Consequently, agricultural plots have spread from low elevations up to
middle and some high elevations on Tutuila.
In summary, deforestation by land-clearing for agriculture has been
the major contributing factor in the loss and degradation of forested
habitat for the mao throughout its range in Samoa and American Samoa,
and logging has been an additional major factor in loss and degradation
of forest habitat in Samoa. The majority of the lowland forests have
either been lost or fragmented by land-clearing for agriculture. Upland
areas in Samoa have suffered extensive deforestation from logging and
are increasingly at risk as agriculture and development expand into
these areas. Based on the above information, we conclude that the
threat of habitat destruction and modification by agriculture and
development is a current threat to the mao and will continue into the
future.
Habitat Destruction and Modification by Nonnative Plants
Nonnative plant species can degrade the habitat of native species
and their impacts to native forest often are facilitated or exacerbated
by the impacts of other threats such as hurricanes, agriculture and
development, and feral ungulates.
The native flora of the Samoan archipelago (plant species that were
present before humans arrived) consisted of approximately 550 taxa, 30
percent of which were endemic (species that occur only in the American
Samoa and Samoa) (Whistler 2002, p. 8). An additional 250 plant species
have been intentionally or accidentally introduced and have become
naturalized with 20 or more of these considered invasive or potentially
invasive in American Samoa (Whistler 2002, p. 8; Space and Flynn 2000,
pp. 23-24). Of these approximately 20 or more nonnative pest plant
species, at least 10 have altered or have the potential to alter the
habitat of the mao and the other four species proposed for listing
(Atkinson and Medeiros 2006, p. 18; Craig 2009, pp. 94, 97-98; ASCC
2010, p. 15).
Nonnative plants can degrade native habitat in Pacific island
environments by: (1) Modifying the availability of light through
alterations of the canopy structure; (2) altering soil-water regimes;
(3) modifying nutrient cycling; (4) ultimately converting native-
dominated plant communities to nonnative plant communities; and (5)
increasing the frequency of landslides and erosion (Smith 1985, pp.
217-218; Cuddihy and Stone, 1990, p. 74; Matson 1990, p. 245; D'Antonio
and Vitousek 1992, p. 73; Vitousek et al. 1997, pp. 6-9; Atkinson and
Medeiros 2006, p. 16). Nonnative plant species often exploit the
disturbance caused by other factors such as hurricanes, agriculture and
development, and feral ungulates, and thus, in combination reinforce or
exacerbate their negative impacts to native habitats. Although the
areas within the National Park of American Samoa (NPSA, on the islands
of Tutuila, Ofu, and Tau) contain many areas that are relatively free
of human disturbance and alien invasion and largely represent pre-
contact vegetation, the threat of invasion and further spread by
nonnative plant species poses immense cause for concern (Atkinson and
Medeiros 2006, p. 17; ASCC 2010, p. 22).
The invasive vines Merremia peltata and Mikania micrantha have
serious impacts in forested areas and prevent reforestation of former
agriculture areas in Samoa and American Samoa; they are prolific
invaders of forest gaps and disturbed sites, and can have a smothering
effect on growing trees, blocking sunlight to sub-canopy and
undergrowth vegetation (MNRE 2013, p. 29). Similarly, several invasive
trees also negatively affect native forests in Samoa by outcompeting
native species
[[Page 61583]]
in forest gaps, getting established and moving further into old
secondary regrowth and primary forests. A significant portion of
Samoa's forest are now classified as secondary re-growth dominated by
invasive tree species such as Falcataria moluccana (albizia, tamaligi),
Castilla elastica (Mexican rubber tree, pulu mamoe), Spathodea
campanulata (African tulip, faapasi), and Funtumia elastica (African
rubber tree, pulu vao) (MNRE 2013, p. 29). In addition, the invasive
shrub Clidemia hirta is found in remote areas of upland forests in
Savaii (Atherton and Jeffries 2012, p. 103). Although the mao forage
and occasionally nest in modified habitat such as plantation areas
where nonnative trees that provide nectar and nesting habitat (e.g.,
Falcataria moluccana) may occur, these habitats lack the high tree-
species diversity preferred by the mao and also place the species at a
greater risk of predation by nonnative predators (see Factor C below)
(Butler and Stirnemann 2013, p. 30). In summary, while the best
available information does not provide the exact distribution of
nonnative plant species, the habitat-modifying impacts of nonnative
species are expected to continue and are not likely to be reduced in
the future. Based on the above information, we conclude that the threat
of habitat destruction and modification by nonnative plant species is a
current threat to the mao and will continue into the future.
The following list provides a brief description of the nonnative
plants that have the greatest negative impacts to the native forest
habitat for the mao in American Samoa (Space and Flynn 2000, pp. 23-24;
Craig 2009, pp. 94, 96-98; ASCC 2010, p. 15):
Adenanthera pavonina (red bean tree, coral bean tree, lopa), native
to India and Malaysia, is a medium-sized tree up to 50 ft (15 m) high
that invades intact forests as well as disturbed sites, and can quickly
form large stands (GISD 2006). In American Samoa, it is invasive in
secondary forests, but also has the ability to become more widely
established on Tutuila and the Manua Islands (Space and Flynn 2000, p.
4). It is considered to have negative impacts on the native forests in
American Samoa because the trees produce large quantities of seed, grow
on a variety of soils, and can overtop many native trees and eventually
form monotypic stands (Space and Flynn 2002, p. 5).
Castilla elastica (Mexican rubber tree, pulu mamoe), native to
tropical America, is a medium-sized tree 15 to 30 ft (5 to 10 m) high
that can invade intact forest where it reproduces prolifically and can
crowd out native species (NPSA 2012, in litt.). It has displaced
significant areas of lowland forest in Samoa, and is now considered to
be an important threat to native forests in American Samoa (Atkinson
and Medeiros 2006, p. 18).
Cinnamomum verum (cinnamon, tinamoni), native to south Asia, is a
fast-growing, medium-sized tree up to 30 ft (9 m) high with aromatic
bark and leaves. It forms dense root mats that inhibit establishment of
other plants, and can shade out other tree species and thus create
monotypic stands. On Tutuila, it is actively spreading in the ridge
forests of Mt. Matafao, Matuu, and Maloata (Space and Flynn 2000, p. 4;
NPSA 2012, in litt.).
The shrub Clidemia hirta (Koster's curse), native to the New World
from Mexico to Argentina, grows to be 6.6 ft (2 m) in height, forms a
dense understory, shades out native plants, and prevents their
regeneration (Wagner et al. 1985, p. 41; Smith 1989, p. 64). On Tau, it
has become a serious problem in the unique summit scrub community
(Whistler 1992, p. 22).
Falcataria moluccana (albizia, tamaligi), native to Moluccas, New
Guinea, New Britain, and the Solomon Islands, is a tree that can reach
131 ft (40 m) in height and has a wide-spreading canopy. It grows
rapidly and outcompetes slow-growing native trees by reducing light
availability, and its abundant, high-nutrient litter alters soil
chemistry (GISD 2008). Its shallow root system may lead to soil
instability and landslides (Atkinson and Medeiros 2006, p. 17).
Funtumia elastica (African rubber tree, pulu vao), is a medium-
sized tree up to 100 ft (30 m) tall native to tropical Africa (U.S.
Department of Agriculture--Agricultural Research Service (USDA) 2006).
This tree is invasive because of its ``parachute seeds'' that can
disperse long distances and germinate in sunny or shady conditions
(Whistler 2002, p. 122). Funtumia has become a dominant subcanopy and
understory tree in the western half of Upolu where it can form
monotypic forests (Pearsall and Whistler 1991, p. 30). It is also
established and becoming dominant on eastern Savaii (Whistler 2002, p.
122). This species has the potential to become a major problem in
American Samoa due to its proximity and the volume of traffic with
Samoa (Space and Flynn 2000, p. 12).
Leucaena leucocephala (wild tamarind, lusina, fua pepe), 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). It crowds out native species and
resprouts vigorously after cutting, and seeds can remain viable for 10
to 20 years (Craig 2009, p. 98).
Merremia peltata (Merremia, fue lautetele), is an indigenous,
sprawling, or high-climbing vine that can invade areas following
disturbances such as land-clearing and hurricanes. This fast-growing
vine can smother plantation and forest trees (Craig 2009, p. 98).
Mikania micrantha (mile-a-minute vine, fue saina), native to
tropical America, is a scrambling or climbing herbaceous vine, that
retards forest regeneration with its smothering growth (Whistler 1994,
p. 42). This sun-loving, shade-intolerant vine is a major pest of
plantations and forests on all major American Samoa islands (Space and
Flynn 2000, p. 5; Craig 2009, p. 94).
Psidium cattleianum (strawberry guava, kuava) is a tall shrub or
small tree that forms dense stands in which few other plants can grow,
displacing native vegetation through competition. The fruit is eaten by
feral pigs and birds that disperse the seeds throughout the forest
(Smith 1985, p. 200; Wagner et al. 1985, p. 24). It is thought to have
been cultivated in American Samoa for more than 40 years and has become
naturalized in lowland rainforest on western Tutuila.
Spathodea campanulata (African tulip, faapasi), native to tropical
Africa, is a large tree up to 80 ft (24 m) or more in height with showy
red-orange tulip-like flowers and pods containing hundreds of wind-
dispersed seeds (Pacific Islands Ecosystems at Risk (PIER) 2013). It is
particularly invasive in low- to mid-elevation forests, and can spread
in open agricultural land, waste areas, and intact native forest,
forming dense stands that shade out other vegetation (GISD 2010).
Habitat Destruction and Modification by Nonnative Ungulates
Feral pigs (Sus scrofa) cause multiple negative impacts to island
ecosystems including the destruction of vegetation, spread of invasive
nonnative plant species, and increased soil erosion. In addition, feral
cattle (Bos taurus) consume tree seedlings and browse saplings, and
combined with undergrowth disturbance, prevent forest regeneration,
subsequently opening the forest to invasion by nonnative species
(Cuddihy 1984, p. 16).
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
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indirect impacts on native plant communities. Pigs are a major vector
for the establishment and spread of 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 serve 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-
Statewide Assessment and Resource Strategy (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, and increasing the likelihood of landslides
(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).
In American Samoa, feral pigs continue to negatively affect
forested habitats. Feral pigs have been present in American Samoa since
antiquity (American Samoa Historic Preservation Office 2015, in litt.).
In the past, hunting pressure kept their numbers down, however,
increasing urbanization and increasing availability of material goods
has resulted in the decline in the practice of pig hunting to almost
nothing (Whistler 1992, p. 21; 1994, p. 41). Feral pigs are moderately
common to abundant in many forested areas, where they spread invasive
plants, damage understory vegetation, and destroy riparian areas by
their feeding and wallowing behavior (DMWR 2006, p. 23; ASCC 2010, p.
15). Feral pigs are a serious problem in the NPSA because of the damage
they cause to native vegetation through their rooting and wallowing
(Whistler 1992, p. 21; 1994, p. 41; Hoshide 1996, p. 2; Cowie and Cook
1999, p. 48; Togia pers. comm. in Loope et al. 2013, p. 321). Such
damage to understory vegetation is likely to reduce foraging
opportunities for the mao. Pig densities have been reduced in some
areas by snaring and hunting, but remain high in other areas (ASCC
2010, p. 15).
In Samoa, feral pigs are present throughout lowland and upland
areas on Savaii, and are considered to have a negative impact on the
ecological integrity of upland forests of Savaii, an important
conservation area for the mao and other rare species (Atherton and
Jeffries 2012, p. 17). During recent surveys, feral pig activity was
common at most sites in upland forests on Savaii, and was even detected
at the upper range of the mao at an elevation of 4,921 ft (1,500 m)
(Atherton and Jefferies 2012, pp. 103, 146). Significant numbers of
feral cattle were present in an upland site where their trampling had
kept open grassy areas within forested flats, and where mao had
previously been observed (Atherton and Jeffries 2012, pp. 103-105).
Trampling in forested areas damages understory vegetation and is likely
to reduce foraging opportunities for mao as well as provide vectors for
invasion by nonnative plants. In summary, the widespread disturbance
caused by feral ungulates is likely to continue to negatively impact
the habitat of the mao. Based on the above information, we conclude
that habitat destruction and modification by feral ungulates is a
threat to the mao.
Conservation Efforts To Reduce Habitat Destruction, Modification, or
Curtailment of Its Range
American Samoa
The National Park of American Samoa (NPSA) was established to
preserve and protect the tropical forest and archaeological and
cultural resources, to maintain the habitat of flying foxes, to
preserve the ecological balance of the Samoan tropical forest, and,
consistent with the preservation of these resources, to provide for the
enjoyment of the unique resources of the Samoan tropical forest by
visitors from around the world (Public Law 100-571, Public Law 100-
336). Under a 50-year lease agreement between local villages, the
American Samoa Government, and the Federal Government, approximately
8,000 ac (3,240 ha) of forested habitat on the islands of Tutuila, Tau,
and Ofu are protected and managed (NPSA Lease Agreement 1993).
Several programs and partnerships to address the threat of
nonnative plant species have been established and are ongoing in
American Samoa. Since 2000, the NPSA has implemented an invasive plant
management program that has focused on monitoring and removal of
nonnative plant threats. The nonnative plant species prioritized for
removal include the following: Adenanthera pavonina or lopa, Castilla
elastica or pulu mamoe, Falcataria moluccana or tamaligi, Leucaena
leucocephala or lusina, and Psidium cattleianum or strawberry guava
(Togia 2015, in litt.). In particular, efforts have been focused on the
removal of the tamiligi from within the boundaries of the NPSA as well
as in adjacent areas (Hughes et al. 2012).
The thrip Liothrips urichi is an insect that was introduced to
American Samoa in the 1970s as a biocontrol for the weed Clidemia hirta
(Tauiliili and Vargo 1993, p. 59). This thrip has been successful at
controlling Clidemia on Tutuila. Though Clidemia is still common and
widespread throughout Tutuila, thrips inhibit its growth and vigor,
preventing it from achieving ecological dominance (Cook 2001, p. 143).
In 2004, the American Samoa Invasive Species Team (ASIST) was
established as an inter-agency team of nine local government and
Federal agencies. The mission of ASIST is to reduce the rate of
invasion and impact of invasive species in American Samoa with the
goals of promoting education and awareness on invasive species and
preventing, controlling, and eradicating invasive species. In 2010, the
U.S. Forest Service conducted an invasive plant management workshop for
Territorial and Federal agencies, and local partners (Nagle 2010 in
litt.). More recently, the NPSA produced a field guide of 15 invasive
plants that the park and its partners target for early detection and
response (NPSA 2012, in litt.).
In 1996, the NPSA initiated a feral pig control program that
includes fencing and removal of pigs using snares in the Tutuila Island
and Tau Island Units. Two fences have been constructed and several
hundred pigs have been removed since 2007 (Togia 2015, in litt.). The
program is ongoing and includes monitoring feral pig activity twice per
year and additional removal actions as needed (Togia 2015, in litt.).
Samoa
In 2006, the Government of Samoa developed a recovery plan for the
mao. The recovery plan identifies goals of securing the mao,
maintaining its existing populations on Upolu and Savaii, and
reestablishing populations at former sites (MNRE 2006). The plan has
eight objectives: (1) Manage key forest areas on Upolu and Savaii where
significant populations of the mao remain; (2) carry out detailed
surveys to identify the numbers of pairs and establish monitoring; (3)
increase understanding of the breeding and
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feeding ecology; (4) establish populations on rat-free islands or new
mainland sites (including feasibility of reintroduction to American
Samoa); (5) evaluate development of a captive-management program; (6)
develop a public awareness and education program; (7) develop
partnerships to assist in the mao recovery; and (8) establish a
threatened bird recovery group to oversee the implementation and review
of this plan and other priority bird species. In 2012, a detailed study
provided information on the mao's diet, habitat use, reproductive
success, and survival; important life-history requirements that can be
used to implement recovery efforts (Butler and Stirnemann 2013).
The Mt. Vaea Ecological Restoration Project surveyed and mapped the
presence of native bird and plant species and invasive plant species
within lowland forest habitat of the 454-ac (183-ha) Mt. Vaea Scenic
Reserve on Upolu, Samoa (Bonin 2008, pp. 2-5). The project was
envisioned as the first demonstration project of invasive species
management and forest restoration in Samoa. Phase I of the project
resulted in the development of a restoration plan recommending removal
of five priority invasive plant species and planting of native tree
species (Bonin 2008, pp. viii, 24). Phase 2 of the project resulted in
identifying techniques for treatment of two problematic rubber species
(Castilla elastica or pulu mamoe and Funtumia elastica or pulu vao) and
replanting areas with native tree species (Bonin 2010, pp. 20-21).
The Two Samoas Environmental Collaboration Initiative brings
together government agencies, nongovernmental organizations and
institutions from American Samoa and Samoa and provides a platform for
a single concerted effort to manage threats to environmental resources
such as the management of fisheries, land-based sources of pollution,
climate change, invasive species, and key or endangered species (MNRE
2014, p. 67). In 2010, a Memorandum of Understanding establishing the
collaborative effort between the two countries was signed by the two
agencies responsible for conservation of species and their habitats,
MNRE (Samoa) and DMWR (American Samoa). This initiative establishes a
framework for efforts to recover the mao in American Samoa and Samoa.
Summary of Factor A
In summary, based on the best available scientific and commercial
information, we conclude that the destruction, modification, and
curtailment of the mao's habitat and range are ongoing threats and
these threats will continue into the future. The destruction and
modification of habitat for the mao is caused by agriculture, logging,
feral ungulates, and nonnative plant species, the impacts of all of
which are exacerbated by hurricanes (see Factor E). The most serious
threat identified has been the loss of forested habitat caused by
forest clearing for agriculture, and logging. All of the above threats
are ongoing and interact to exacerbate the negative impacts and
increase the vulnerability of extinction of the mao.
B. Overutilization for Commercial, Recreational, Scientific, or
Educational Purposes
In Samoa, there is anecdotal information suggesting that the mao
has been shot by people who were afraid of their calls (MNRE 2006, p.
8). In addition, one individual reported that mao are eaten, or were
eaten in the past, but it seems more likely these birds were shot
accidentally by hunters who were targeting pigeons (MNRE 2006, p. 8).
The mao has been protected under regulations enacted by the Government
of Samoa in 1993 and revised in 2004 (MNRE 2006, p. 8). The best
available information does not indicate overutilization for commercial,
recreation, scientific, or educational purposes in American Samoa.
Based on the above information, we conclude that hunting of the mao is
unintentional or accidental; therefore, we do not consider the
overutilization for commercial, recreational, scientific, or
educational purposes to be a threat to the mao.
C. Disease or Predation
Predation
Nest predation by rats has negative impacts on many island birds,
including the mao (Atkinson 1977, p. 129; 1985, pp. 55-70; Butler and
Stirnemann 2013, p. 29; O'Donnell et al. 2015, pp. 24-26). Rats have
been identified as the main cause of decline in the closely related
Gymnomyza aubryana in New Caledonia (MNRE 2006, p. 8). Juveniles
spending time on the forest floor are also at risk from predation by
feral cats (Butler and Stirnemann 2013, p. 31). Other potential
predators include the native barn owl (Tyto alba) and wattled
honeyeater (Foulehaio carunculatus); however, adults can potentially
drive these species away from the nest (Butler and Stirnemann 2013, p.
31).
Butler and Stirnemann (2013, p. 29) captured footage of one nest
depredation event by a black rat, which took a mao egg. The rat gained
access to the egg by jumping on the incubating female's back from the
branch above, driving the female off the nest. Combined with the
disappearance of two females during the breeding season, this footage
suggests that adult females are potentially vulnerable to predation on
the nest at night, while they are incubating (Butler and Stirnemann
2013, p. 31), a phenomenon documented or suspected in other island bird
species, which lack innate behavioral defenses against nonnative
mammalian predators (see for example Robertson et al. 1994, p. 1,084;
Armstrong et al. 2006, p. 1,034; VanderWerf 2009, p. 741). This
potential bias toward predation of females has the potential to create
a skewed sex ratio in mao populations (Robertson et al. pp. 1,083-
1,084).
The location of mao nests affects their vulnerability to predation
by rats; nests in close proximity to plantation habitats, where rats
are most abundant, are particularly susceptible and experience low
reproductive success (Butler and Stirnemann 2013, p. 31). Nests within
50 meters of a plantation are 40 percent more likely to be depredated
than nests in forested areas farther from plantations (Butler and
Stirnemann 2013, p. 31). Because good-quality, closed-canopy forest
habitat remains in American Samoa, factors in addition to deforestation
are likely responsible for the extirpation of the mao from American
Samoa (MNRE 2006, p. 8), including predation by rats (Stirnemann 2015,
in litt.). Habitat loss from clearing of native forest combined with an
expansion of plantations in Samoa may lead to an increase in rat
populations (which find ample food in plantation habitats) and a
potential for an increase in the mao nest predation rate. In addition,
the mao's low reproductive rate (one juvenile per year) and extended
breeding season increase the likelihood of population-level effects of
predation (Butler and Stirnemann 2013, p. 22).
Predation by feral cats has been directly responsible for the
extinction of numerous birds on oceanic islands (Medina et al. 2011, p.
6). Native mammalian carnivores are absent from oceanic islands because
of their low dispersal ability, but once introduced by humans, they
become significant predators on native animals such as seabirds and
landbirds that are not adapted to predation by terrestrial carnivores
(Nogales et al. 2013, p. 804; Scott et al. 1986, p. 363; Ainley et al.
1997, p. 24; Hess and Banko 2006, in litt.). The considerable amount of
time
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spent on the ground (up to 7 days) and poor flight ability of mao
chicks post-fledging increases the risk of predation by feral cats
(Butler and Stirnemann 2013, p. 28). Evidence of feral cat presence
exists in montane forests and along an elevational gradient on Savaii,
including numerous scats (feces) containing rodent hairs and bird bones
and feathers (Atherton and Jeffries 2012, pp. 76, 103), and predation
by feral cats has been posited as a contributing factor in the mao's
extirpation from Tutuila (Stirnemann 2015 in litt.). Based on the above
information, we conclude that predation by rats and cats is a threat to
the mao that is likely to continue in the future.
Disease
Recent investigations suggest that avian malaria may be indigenous
and non-pathogenic in American Samoa and, therefore, is unlikely to
affect bird populations (Jarvi et al. 2003, p. 636; Seamon 2004a, in
litt.). The best available information does not indicate there are
other diseases affecting the mao populations in Samoa (MNRE 2006, p.
8).
Conservation Efforts To Reduce Disease or Predation
A project to restore habitat for the mao and other priority species
by removing the threat of predation by the Polynesian rat (R. exulans)
was attempted on the uninhabited islands of Nuutele (267 ac (108 ha))
and Nuulua (62 ac (25 ha)) off the eastern end of Upolu, Samoa (Tye
2012, in litt). The demonstration project aimed to eradicate the
Polynesian rat from both islands through aerial delivery of baits.
Post-project monitoring detected rats on Nuutele, suggesting that rats
survived the initial eradication effort or were able to recolonize the
island (Tye 2012, in litt.).
Summary of Factor C
In summary, based on the best available scientific and commercial
information, we conclude that disease is not a current threat to the
mao, nor is it likely to become a threat in the future. Because of its
low reproductive rate (1 egg per clutch) and vulnerability to predation
at multiple life-history stages (eggs, chicks, fledglings, and adults),
we conclude that the threat of predation by rats and feral cats is an
ongoing threat to the mao that will continue into the future.
D. The Inadequacy of Existing Regulatory Mechanisms
The Act requires that the Secretary assess available regulatory
mechanisms in order to determine whether existing regulatory mechanisms
may be inadequate as designed to address threats to the species being
evaluated (Factor D). Under this factor, we examine whether existing
regulatory mechanisms are inadequate to address the potential threats
to the mao discussed under other factors. In determining whether the
inadequacy of regulatory mechanisms constitutes a threat to the mao, we
analyzed the existing Federal, Territorial, and international laws and
regulations that may address the threats to this species or contain
relevant protective measures. Regulatory mechanisms, if they exist, may
preclude the need for listing if we determine that such mechanisms
adequately address the threats to the species such that listing is not
warranted.
Samoa
The Government of Samoa has enacted numerous laws and regulations
and has signed on to various international agreements that address a
wide range of activities such as land tenure and development,
biodiversity, wildlife protection, forestry management, national parks,
biosecurity, and the extraction of water resources (MNRE 2013, pp. 148-
149; MNRE 2014, p. 57).
The Protection of Wildlife Regulations 2004 regulates the
protection, conservation, and utilization of terrestrial or land-
dwelling species (MNRE and SPREP 2012, p. 5). These regulations
prohibit, and establish penalties for committing, the following
activities: (1) The take, keep, or kill of protected and partially
protected animal species; (2) harm of flying species endemic to Samoa;
and (3) the export of any bird from Samoa (MNRE and SPREP 2012, pp. 5-
6). The mao is endemic to the Samoan archipelago, but it is not listed
as a ``flying species endemic to Samoa'' under these regulations.
The Planning and Urban Management Act 2004 (PUMA) and PUMA
Environmental Impact Assessment (EIA) Regulation (2007) were enacted to
ensure all development initiatives are properly evaluated for adverse
environmental impacts (MNRE 2013, p. 93). The information required for
Sustainable Management Plans and Environmental Impact Assessments does
not include specific consideration for species or their habitat
(Planning and Urban Management Act 2004, as amended). Other similar
approval frameworks mandated under other legislation address specific
threats and activities. These include the permit system under the Lands
Surveys and Environment Act 1989 for sand mining and coastal
reclamation, and ground water exploration and abstraction permits under
the Water Resources Act 2008 (MNRE 2013, p. 93). The PUMA process has
been gaining in acceptance and use, however, information on its
effectiveness in preventing adverse impacts to species or their
habitats is lacking (MNRE 2013, p. 93).
The Forestry Management Act 2011 regulates the effective and
sustainable management and utilization of forest resources. This law
creates the requirement for a permit or license for commercial logging
or harvesting of native, agro-forestry, or plantation forest resources
(MNRE and SPREP 2012, p. 18). Permitted and licensed activities must
follow approved Codes of Practice, forestry harvesting plans, and other
requirements set by the Ministry of Natural Resources and Environment.
License or permit holders must also follow laws relating to national
parks and reserves, and all provisions of management plans for any
national park or reserve. Under this act, lands designated as protected
areas for the purposes of the protection of biodiversity and endangered
species prohibit any clearing for cultivation or removal of forest
items from protected areas without prior consent of the MNRE (Forestry
Management Act 2011, Para. 57). Although this law includes these
general considerations for managing forest resources, it does not
specifically provide protection to habitat for the mao.
The Quarantine (Biosecurity) Act 2005 forms part of the system to
combat the introduction of invasive species and manage existing
invasions. It is the main legal instrument to manage the deliberate or
accidental importation of invasive species, pests, and pathogens and
also to deal with such species should they be found in Samoa (MNRE and
SPREP 2012, p. 38). This legislation also provides a risk assessment
procedure for imported animals, plants and living modified organisms.
Although this law provides for management of invasive species,
including those that degrade or destroy native forest habitat for the
mao, we do not have information indicating the degree to which it has
been implemented or effectiveness of such efforts.
In Samoa, there are several regulatory and nonregulatory protected
area systems currently in place that protect and manage terrestrial
species and their habitats; these include national parks, nature
reserves, conservation areas, and village agreements. The National
Parks and Reserves Act (1974) created the
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statutory authority for the protection and management of national parks
and nature reserves. Conservation areas, unlike national parks and
nature reserves, emphasize the importance of conservation, but at the
same time address the need for sustainable development activities
within the conservation area. Village agreements are voluntary
agreements or covenants developed and signed by local villages and
conservation organizations that stipulate specific conservation
measures or land use prohibitions in exchange for significant
development aid. As of 2014, a total of approximately 58,176 ac (23,543
ha), roughly 8 percent of the total land area of Samoa (285,000 ha)
were enlisted in terrestrial protected areas, with the majority located
in five national parks covering a total of 50,629 ac (20,489 ha)
overlapping several key conservation areas identified for the mao (MNRE
2006, p. 14; MNRE 2014, p. 57).
Conservation International (CI) and the Secretariat of the Pacific
Regional Environment Programme (SPREP) in collaboration with the
Ministry of Natural Resources Environment identified eight terrestrial
Key Biodiversity Areas (KBAs) intended to ensure representative
coverage of all native ecosystems with high biodiversity values, five
of which are targeted to benefit the conservation of the mao (CI et al.
2010, p. 12): Eastern Upolu Craters, Uafato-Tiavea Coastal Forest, O le
Pupu Pue National Park, Apia Catchments, and Central Savaii Rainforest.
All five KBAs also overlap with Important Bird Areas designated by
BirdLife International (Schuster 2010, pp. 16-43). Currently, these
five KBAs, which are nonregulatory, are under various degrees of
protection and conservation management including national parks,
Community Conservation Areas, and areas with no official protective
status (CI et al. 2010, p. 12). Many of the KBAs and protected areas
mentioned above are still faced with increasing pressures in large part
due to difficulties of their location on customary lands (traditional
village system) and the ongoing threats of development, invasive
species, and logging (MNRE 2009, p. 1; CI et al. 2010, p. 12). The
decline of closed forest habitat has been a result of logging on Savaii
and agricultural clearing on the edges of National Parks and Reserves
(MNRE 2006, p. 5).
In 2006, the Government of Samoa developed a recovery plan for the
mao. The recovery plan identifies goals of securing the mao,
maintaining its existing populations on Upolu and Savaii, and
reestablishing populations at former sites (MNRE 2006). This plan is
nonregulatory in nature.
In summary, existing regulatory mechanisms have the potential to
address the threat of habitat destruction and degradation to the mao in
Samoa. However, these policies and legislation may not provide the
protection necessary for the conservation of the mao in Samoa.
American Samoa
In American Samoa no existing Federal laws, treaties, or
regulations specify protection of the mao's habitat from the threat of
deforestation, or address the threat of predation by nonnative mammals
such as rats and feral cats. However, some existing Territorial laws
and regulations have the potential to afford the species some
protection but their implementation does not achieve that result. The
DMWR is given statutory authority to ``manage, protect, preserve, and
perpetuate marine and wildlife resources'' and to promulgate rules and
regulations to that end (American Samoa Code Annotated (ASCA), title
24, chapter 3). This agency conducts monitoring surveys, conservation
activities, and community outreach and education about conservation
concerns. However, to our knowledge, the DMWR has not used this
authority to undertake conservation efforts for the mao such as habitat
protection and control of nonnative predators such as rats and cats
(DMWR 2006, pp. 79-80).
The Territorial Endangered Species Act provides for appointment of
a Commission with the authority to nominate species as either
endangered or threatened (ASCA, title 24, chapter 7). Regulations
adopted under the Coastal Management Act (ASCA Sec. 24.0501 et seq.)
also prohibit the taking of threatened or endangered species (ASAC
Sec. 26.0220.I.c). However, the ASG has not listed the mao as
threatened or endangered so these regulatory mechanisms do not provide
protection for this species.
Under ASCA, title 24, chapter 08 (Noxious Weeds), the Territorial
DOA has the authority to ban, confiscate, and destroy species of plants
harmful to the agricultural economy. Similarly, under ASCA, title 24,
chapter 06 (Quarantine), the director of DOA has the authority to
promulgate agriculture quarantine restrictions concerning animals.
These laws may provide some protection against the introduction of new
nonnative species that may have negative effects on the mao's habitat
or become predators of the mao, but these regulations do not require
any measures to control invasive nonnative plants or animals that
already are established and proving harmful to native species and their
habitats (DMWR 2006, p. 80) (see Factor D for the Pacific sheath-tailed
bat, above).
As described above, the Territorial Coastal Management Act
establishes a land use permit (LUP) system for development projects and
a Project Notification Review System (PNRS) for multi-agency review and
approval of LUP applications (ASAC Sec. 26.0206). The standards and
criteria for review of LUP applications include requirements to protect
Special Management Areas (SMA), Unique Areas, and ``critical habitats''
(ASCA Sec. 24.0501 et. seq.). To date, the SMAs that have been
designated (Pago Pago Harbor, Leone Pala, and Nuuuli Pala; ASAC Sec.
26.0221), do not provide habitat for the mao. The only Unique Area
designated to date, the Ottoville Rainforest (American Samoa Coastal
Management Program 2011, p. 52), hypothetically may provide some
foraging habitat for the mao, but it is a small (20-ac (8-ha)) island
of native forest in the middle of the heavily developed Tafuna Plain
(Trail 1993, pp. 1, 4), far from large areas of native forest. These
laws and regulations are designed to ensure that ``environmental
concerns are given appropriate consideration,'' and include provisions
and requirements that could address to some degree threats to native
forest habitat required by the mao, even though individual species are
not named (ASAC Sec. 26.0202 et seq.). Because the implementation of
these regulations has been minimal and review of permits is not
rigorous, issuance of permits may not provide the habitat protection
necessary to provide for the conservation of the mao and instead result
in loss of native forest habitat important to the mao and other species
as a result of land clearing for agriculture and development (DMWR
2006, p. 71). We conclude that the implementation of the Coastal
Management Act and its PNRS is inadequate to address the threat of
habitat destruction and degradation to the mao (see Factor D for the
Pacific sheath-tailed bat for further details).
Summary of Factor D
In summary, existing Territorial laws and regulatory mechanisms
have the potential to offer some level of protection for the mao and
its habitat if it were to be reintroduced to American Samoa but are not
currently implemented in a manner that would do so. The DMWR has not
exercised its statutory authority to address threats to the mao such as
predation by nonnative predators, the mao is not listed pursuant
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to the Territorial Endangered Species Act, and the Coastal Management
Act and its implementing regulations have the potential to address the
threat of habitat loss to deforestation more substantively, but this
law is inadequately implemented.
Based on the best available information, no existing Federal
regulatory mechanisms address the threats to the mao. Some existing
regulatory mechanisms in Samoa and American Samoa have the potential to
offer some protection of the mao and its habitat, but their
implementation does not reduce or remove threats to the species such as
habitat destruction or modification or predation by nonnative species.
For these reasons, we conclude that existing regulatory mechanisms do
not address the threats to the mao.
E. Other Natural or Manmade Factors Affecting Its Continued Existence
Hurricanes
Hurricanes are a common natural disturbance in the tropical Pacific
and have occurred in the Samoan archipelago with varying frequency and
intensity (see Factor E discussion for the Pacific sheath-tailed bat).
Catastrophic events such as hurricanes can be a major threat to the
persistence of species already experiencing population-level impacts of
other stressors (MNRE 2006, p. 8). Two storms in the 1990s, Cyclones
Ofa (1990) and Val (1991), severely damaged much of the remaining
forested habitat in Samoa, reducing forest canopy cover by 73 percent
(MNRE 2006, pp. 5, 7). In addition, Cyclone Evan struck Samoa in 2012
causing severe and widespread forest damage, including defoliation and
downed trees in 80 to 90 percent of the Reserves and National Parks on
Upolu (Butler and Stirnemann 2013, p. 41). Secondary forests also were
severely damaged by the storm, and most trees in the known mao
locations were stripped of their leaves, fruits, and flowers (Butler
and Stirnemann 2013, p. 41). Hurricanes thus exacerbate forest
fragmentation and invasion of native forests by nonnative species,
stressors that reduce breeding, nesting, and foraging habitat for the
mao (see Factor A, above). Although severe storms are a natural
disturbance with which the mao has coexisted for millennia, such storms
exacerbate the threats to its remaining small, isolated populations by
at least temporarily damaging or redistributing habitat and food
resources for the birds and causing direct mortality of individuals
(Wiley and Wunderle 1993, pp. 340-341; Wunderle and Wiley 1996, p.
261). If the mao was widely distributed, had ample habitat and
sufficient numbers, and were not under chronic pressure from
anthropogenic threats such as introduced predators, it might recover
from hurricane-related mortality and the temporary loss or
redistribution of resources in the wake of severe storms. However, this
species' current status makes it highly vulnerable to catastrophic
chance events, such as hurricanes, which occur frequently throughout
its range in Samoa and American Samoa.
Low Numbers of Individuals and Populations
Species with low numbers of individuals, restricted distributions,
and small, isolated populations are often more susceptible to
extinction as a result of natural catastrophes such as hurricanes or
disease outbreaks, demographic fluctuations, or inbreeding depression
(Shaffer 1981, p. 131; see Factor E discussion for the Pacific sheath-
tailed bat, above). These problems associated with small population
size are further magnified by interactions with each other and with
other threats, such as habitat loss and predation (Lacy 2000, pp. 45-
47; see Factor A and Factor C, above).
We consider the mao to be vulnerable to extinction because of
threats associated with its low number of individuals--perhaps not more
than a few hundred birds--and low numbers of populations. These threats
include environmental catastrophes, such as hurricanes, which could
immediately extinguish some or all of the remaining populations;
demographic stochasticity that could leave the species without
sufficient males or females to be viable; and inbreeding depression or
loss of adaptive potential that can be associated with loss of genetic
diversity and result in eventual extinction (Shaffer 1981, p. 131; Lacy
2000, pp. 40, 44-46). Combined with ongoing habitat destruction and
modification by logging, agriculture, development, nonnative plant
species, and feral ungulates (Factor A) and predation by rats and feral
cats (Factor C), the effects of these threats to small populations
further increases the risk of extinction of the mao.
Climate Change
Our analyses under the Act include consideration of ongoing and
projected changes in climate (see Factor E discussion for the Pacific
sheath-tailed bat). The magnitude and intensity of the impacts of
global climate change and increasing temperatures on western tropical
Pacific island ecosystems currently are unknown. In addition, there are
no climate change studies that address impacts to the specific habitats
of the mao. The scientific assessment completed by the Pacific Science
Climate Science Program provides general projections or trends for
predicted changes in climate and associated changes in ambient
temperature, precipitation, hurricanes, and sea level rise for
countries in the western tropical Pacific region including Samoa (used
also as a proxy for American Samoa) (Australian BOM and CSIRO 2011,
Vol. 1 & Vol. 2; see Factor E discussion for the Pacific sheath-tailed
bat for summary).
Although we do not have specific information on the impacts of the
effects of climate change to the mao, increased ambient temperature and
precipitation, and increased severity of hurricanes, would likely
exacerbate other threats to this species as well as provide additional
stresses on its habitat. 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). The mao is limited by its restricted range and low
numbers of individuals. Therefore, we expect this species to be
particularly vulnerable to the environmental effects of climate change
and subsequent impacts to its habitat, even though the specific and
cumulative effects of climate change on the mao are presently unknown
and we are not able to determine the magnitude of this future threat
with confidence. Based on the above information, we conclude that
habitat impacts resulting from the effects of climate change are not a
current threat but are likely to become a threat to the mao in the
future.
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 of hurricanes and low numbers of
individuals that negatively impact the mao. However, the completion of
a recovery plan, basic research on the mao's life-history requirements,
population monitoring, and cooperation between the governments of
American Samoa and Samoa contribute to the conservation of the mao.
Proposed Determination for the Mao
We have carefully assessed the best scientific and commercial
information available regarding the past, present, and future threats
to mao. This large honeyeater endemic to the Samoan archipelago is
vulnerable to extinction
[[Page 61589]]
because of the loss and degradation of its forested habitat, predation
by nonnative mammals, and the impact of stochastic events to species
that are reduced to small population size and limited distribution.
The threat of habitat destruction and modification from
agriculture, logging, and development, nonnative plants, and nonnative
ungulates is occurring throughout the range of the mao, and is not
likely to be reduced in the future (Factor A). The threat of predation
from nonnative predators such as rats and feral cats is ongoing and
likely to continue in the future (Factor C). Existing regulatory
mechanisms do not address the threats to this species (Factor D).
Additionally, the low numbers of individuals and populations of the mao
render the species vulnerable to environmental catastrophes such as
hurricanes, demographic stochasticity, and inbreeding depression
(Factor E). These factors pose threats to the mao whether we consider
their effects individually or cumulatively. All of these threats are
likely to continue in the future.
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 the mao is presently in
danger of extinction throughout its entire range based on the severity
and immediacy of threats currently impacting the species.
Therefore, on the basis of the best available scientific and
commercial information, we propose listing mao as endangered in
accordance with sections 3(6) and 4(a)(1) of the Act. We find that the
mao is presently in danger of extinction throughout its entire range
based on the severity and immediacy of the ongoing and projected
threats described above. The loss and degradation of its forested
habitat, predation by nonnative mammals, limited distribution, the
effects of small population size, and stochastic events such as
hurricanes render this species in its entirety highly susceptible to
extinction as a consequence of these imminent threats; the species' low
reproductive rate reduces its ability to recover from impacts of
multiple threats and their cumulative effects.
Under the Act and our implementing regulations, a species may
warrant listing if it is in danger of extinction or likely to become so
throughout all or a significant portion of its range. Because we have
determined that the mao is endangered throughout all of its range, no
portion of its range can be ``significant'' for purposes of the
definitions of ``endangered species'' 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, July 1,
2014).
American Samoa Population of the Friendly Ground-Dove, Gallicolumba
stairi, Tuaimeo
The genus Gallicolumba is distributed throughout the Pacific and
Southeast Asia and is represented in the oceanic Pacific by six
species. Three species are endemic to Micronesian islands or
archipelagos, two are endemic to island groups in French Polynesia, and
Gallicolumba stairi is endemic to Samoa, Tonga, and Fiji (Sibley and
Monroe 1990, p. 206). The species name used here, the friendly ground-
dove, was derived from ``Friendly Islands'' (i.e., Tonga), where it is
purported to have been first collected (Watling 2001, p. 118). Because
of its shy and secretive habits, this species is also often referred to
as the shy ground-dove (Pratt et al. 1997, pp. 194-195). Some authors
recognize two subspecies of the friendly ground-dove: One, slightly
smaller, in the Samoan archipelago (G. s. stairi), and the other in
Tonga and Fiji (G. s. vitiensis) (Mayr 1945, pp. 131-132). However,
morphological differences between the two are slight (Watling 2001, p.
117), and no genetic or other studies have validated the existence of
separate subspecies.
We accept the current taxonomic treatment of the friendly ground-
dove as Gallicolumba stairi as described in the IOC World Bird List
Version 5.1 compiled by the International Ornithologists Union
Committee on Nomenclature (Gill and Donsker 2015) and ITIS (2015b).
However, recent molecular analyses suggest that the species ascribed to
Gallicolumba are not monophyletic, and recommend reinstalling the name
Alopecoenas for some Gallicolumba species, including G. stairi, thus
including it in a monophyletic radiation of ten species distributed in
New Guinea, the Lesser Sundas, and Oceania (Jonsson et al. 2011, pp.
541-542; Moyle et al. 2013, pp. 1,064-1,065). This recommendation also
parallels the natural divide based on plumage patterns of birds
distributed on either side of New Guinea: The ``bleeding hearts'' with
a red-orange breast patch, which occur in the Philippines and are
recommended to remain in Gallicolumba, and the other ground-doves with
a white or gray breast and head, which occur on Pacific Islands and New
Guinea and are recommended for placement in Alopecoenas (Jonsson et al.
2011, p. 538). Nevertheless, at this time, there is lack of consensus
for the generic change from Gallicolumba to Alopecoenas, as well as the
lack of evidence for validation of a subspecies, G. s.stairi,
restricted to the Samoan archipelago. Therefore, we are evaluating the
status of G. stairi in this proposed rule.
The friendly ground-dove is a medium-sized dove, approximately 10
in (26 cm) long. Males have rufous-brown upperparts with a bronze-green
iridescence, the crown and nape are grey, the wings rufous with a
purplish luster, and the tail is dark brown. The abdomen and belly are
dark brown-olive, while the breast shield is dark pink with a white
border. Immature birds are similar to adults but are uniformly brown.
Females are dimorphic in Fiji and Tonga, where a brown phase (tawny
underparts and no breast shield) and pale phase (similar to males but
duller) occur. In Samoa and American Samoa, only the pale phase is
known to occur (Watling 2001, p. 117).
In American Samoa, the friendly ground-dove is typically found on
or near steep, forested slopes, particularly those with an open
understory and fine scree or exposed soil (Tulafono 2006, in litt.).
Elsewhere the species is known to inhabit brushy vegetation or native
forest on offshore islands, native limestone forest (Tonga), and forest
habitats on large, high islands (Steadman and Freifeld 1998, p. 617;
Clunie 1999, pp. 42-43; Freifeld et al. 2001, p. 79; Watling 2001, p.
118). This bird spends most of its time on the ground, and feeds on
seeds, fruit, buds, snails, and insects (Clunie 1999, p. 42; Craig
2009, p. 125). The friendly ground-dove typically builds a nest of
twigs several feet from the ground or in a tree fern crown, and lays
one or two white eggs (Clunie 1999, p. 43).
The friendly ground-dove is uncommon or rare throughout its range
in Fiji, Tonga, Wallis and Futuna, Samoa, and American Samoa (Steadman
and Freifeld 1998, p. 626; Schuster et al. 1999, pp. 13, 70; Freifeld
et al. 2001, pp. 78-79; Watling 2001, p. 118; Steadman 1997, pp. 745,
747), except for on some small islands in Fiji (Watling 2001, p. 118).
The status of the species as a whole is not monitored closely
throughout its range, but based on available information, the friendly
ground-dove persists in very small numbers in Samoa (Schuster et al.
1999, pp. 13, 70; Freifeld et al. 2001, pp. 78-79), and is considered
to be among the most endangered of native Samoan bird
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species (Watling 2001, p. 118). In Tonga, the species occurs primarily
on small, uninhabited islands and in one small area of a larger island
(Steadman and Freifeld 1998, pp. 617-618; Watling 2001, p. 118). In
Fiji, the friendly ground-dove is thought to be widely distributed but
uncommon on large islands and relatively common on some small islands
(Watling 2001, p. 118).
In American Samoa, the species was first reported on Ofu in 1976
(Amerson et al. 1982, p. 69), and has been recorded infrequently on Ofu
and more commonly on Olosega since the mid-1990s (Amerson et al. 1982,
p. 69; Seamon 2004a, in litt.; Tulafono 2006, in litt.). Amerson et al.
(1982, p. 69) estimate a total population of about 100 birds on Ofu and
possibly Olosega. Engbring and Ramsey (1989, p. 57) described the
population on Ofu as ``very small,'' but did not attempt a population
estimate. More than 10 ground-doves were caught on Olosega between 2001
and 2004, suggesting that numbers there are greater than on Ofu, but
birds may move between the two islands (Seamon 2004a, in litt.), which
once were a single land mass and are today connected by a causeway that
is roughly 490 feet (ft) (150 meters (m)) long. No current population
estimate is available; the secretive habits of this species make
monitoring difficult. Monitoring surveys over the last 10 years do not,
however, suggest any change in the relative abundance of the friendly
ground-dove (Seamon 2004a, in litt.). The DMWR biologists regularly
observe this species at several locations on Ofu and Olosega (DMWR
2013, in litt.), and have initiated a project to color band the
population in order to better describe their distribution and status on
the two islands (Miles 2015b, in litt.).
Distinct Population Segment (DPS) Analysis
Under the Act, we have the authority to consider for listing any
species, subspecies, or for vertebrates, any distinct population
segment (DPS) of these taxa if there is sufficient information to
indicate that such action may be warranted. To guide the implementation
of the DPS provisions of the Act, we and the National Marine Fisheries
Service (National Oceanic and Atmospheric Administration--Fisheries),
published the Policy Regarding the Recognition of Distinct Vertebrate
Population Segments Under the Endangered Species Act (DPS Policy) in
the Federal Register on February 7, 1996 (61 FR 4722). Under our DPS
Policy, we use two elements to assess whether a population segment
under consideration for listing may be recognized as a DPS: (1) The
population segment's discreteness from the remainder of the species to
which it belongs and (2) the significance of the population segment to
the species to which it belongs. If we determine that a population
segment being considered for listing is a DPS, then the population
segment's conservation status is evaluated based on the five listing
factors established by the Act to determine if listing it as either
endangered or threatened is warranted. Below, we evaluate the American
Samoa population of the friendly ground-dove to determine whether it
meets the definition of a DPS under our Policy.
Discreteness
Under our DPS Policy, a population segment of a vertebrate taxon
may be considered discrete if it satisfies either one of the following
conditions: (1) It is markedly separated from other populations of the
same taxon as a consequence of physical, physiological, ecological, or
behavioral factors. Quantitative measures of genetic or morphological
discontinuity may provide evidence of this separation; (2) It is
delimited by international governmental boundaries within which
differences in control of exploitation, management of habitat,
conservation status, or regulatory mechanisms exist that are
significant in light of section 4(a)(1)(D) of the Act.
The American Samoa population of the friendly ground-dove, a
cryptic, understory-dwelling dove not noted for long-distance
dispersal, is markedly separate from other populations of the species.
The genus Gallicolumba is widely distributed in the Pacific, but
populations of the friendly ground-dove are restricted to a subset of
islands (often small, offshore islets) in any archipelago where they
occur, or even to limited areas of single islands in Polynesia
(Steadman and Freifeld 1998, pp. 617-618; Freifeld et al. 2001, p. 79;
Watling 2001, p. 118). Unlike other Pacific Island columbids, this
species does not fly high above the canopy; it is an understory species
that forages largely on the ground and nests near the ground (Watling
2001, p. 118). Furthermore, members of the genus that are restricted to
individual archipelagos, single islands, or offshore islets, are
presumed to be relatively sedentary, weak, or reluctant fliers, with
inter-island flights rarely observed (Baptista et al. 1997, pp. 95,
179-187, Freifeld et al. 2001, p. 79). Therefore, there is a low
likelihood of frequent dispersal or immigration over the large
distances that separate the American Samoa population on Ofu and
Olosega islands from the other populations in Samoa (118 miles mi (190
km)), Tonga (430 mi (690 km)), and Fiji (more than 625 mi (1,000 km)).
In addition, the American Samoan island of Tutuila lies between the
American Samoa population and the nearest population in Samoa, and no
Tutuila records of the friendly ground-dove exist. For these reasons,
it is likely that populations of the friendly ground-dove, which occur
in three archipelagos, are ecologically isolated from each other (i.e.,
the likelihood is low that a population decimated or lost would be
rebuilt by immigration from another population), although some level of
exchange on an evolutionary timescale likely occurs.
Based on the our review of the available information, we have
determined that the American Samoa population of the friendly ground-
dove is markedly separate from other populations of the species due to
geographic (physical) isolation from friendly ground-dove populations
in Samoa, Tonga, and Fiji (Fig. 1). The geographic distance between the
American Samoa population and other populations coupled with the low
likelihood of frequent long-distance exchange between populations
further separate the American Samoa population from other populations
of this species throughout its range. Therefore, we have determined
that the American Samoa population of friendly ground-dove meets a
condition of our DPS policy for discreteness.
Significance
Under our DPS Policy, once we have determined that a population
segment is discrete, we consider its biological and ecological
significance to the larger taxon to which it belongs. This
consideration may include, but is not limited to: (1) Evidence of the
persistence of the discrete population segment in an ecological setting
that is unusual or unique for the taxon, (2) evidence that loss of the
population segment would result in a significant gap in the range of
the taxon, (3) evidence that the population segment represents the only
surviving natural occurrence of a taxon that may be more abundant
elsewhere as an introduced population outside its historical range, or
(4) evidence that the discrete population segment differs markedly from
other populations of the species in its genetic characteristics. One of
these criteria is met. We have found substantial evidence that loss of
the American Samoa population of the friendly ground-dove would
constitute a
[[Page 61591]]
significant gap in the range of this species, and thus this population
meets our criteria for significance under our Policy.
The American Samoa population of the friendly ground-dove
represents the easternmost distribution of this species. The loss of
this population would truncate the species' range by approximately 100
mi (161 km), or approximately 15 percent of the linear extent of its
range, which trends southwest-to-northeast from Fiji to Tonga to Wallis
and Futuna, Samoa, and American Samoa. Unlike other Pacific Island
columbids, this species does not fly high above the canopy; it is an
understory species that forages largely on the ground and nests near
the ground (Watling 2001, p. 118). Because of its flight limitations,
the friendly ground-dove is unlikely to disperse over the long
distances between American Samoa and the nearest surrounding
populations. Therefore, the loss of the American Samoa population
coupled with the low likelihood of recolonization from the nearest
source populations in Samoa, Fiji, and Tonga, would create a
significant gap in the range of the friendly ground-dove.
Summary of DPS Analysis Regarding the American Samoa Population of the
Friendly Ground-Dove
Given that both the discreteness and the significance elements of
the DPS policy are met for the American Samoa population of the
friendly ground-dove, we find that the American Samoa population of the
friendly ground-dove is a valid DPS. Therefore, the American Samoa DPS
of friendly ground-dove is a listable entity under the Act, and we now
assess this DPS's conservation status in relation to the Act's
standards for listing, (i.e., whether this DPS meets the definition of
an endangered or threatened species under the Act).
BILLING CODE 4333-15-C
[GRAPHIC] [TIFF OMITTED] TP13OC15.007
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Summary of Factors Affecting the American Samoa DPS of the Friendly
Ground-Dove
A. The Present or Threatened Destruction, Modification, or Curtailment
of Its Habitat or Range
Habitat Destruction and Modification by Agriculture and Development
The loss or modification of lowland and coastal forests has been
implicated as a limiting factor for populations of the friendly ground-
dove and has likely pushed this species into more disturbed areas or
forested habitat at higher elevations (Watling 2001, p. 118). Several
thousand years of subsistence agriculture and more recent, larger-scale
agriculture has resulted in the alteration and great reduction in area
of forests at lower elevations in American Samoa (see Factor A
discussion for the mao). On Ofu, the coastal forest where the ground-
dove has been recorded, and which may be the preferred habitat for this
species range-wide (Watling 2001, p. 118), largely has been converted
to villages, grasslands, or coconut plantations (Whistler 1994, p.
127). However, none of the land-clearing or development projects
proposed for Ofu or Olosega in recent years has been approved or
initiated in areas known to be frequented by friendly ground-doves
(Tulafono 2006, in litt.; Stein et al. 2014, p. 25). Based on the above
information, we find that agriculture and development have caused
substantial destruction and modification of the habitat of the friendly
ground-dove in American Samoa, potentially resulting in the curtailment
of its range in American Samoa. Habitat destruction and modification by
agriculture is expected to continue into the future, but probably at a
low rate; the human population on Ofu and Olosega has been declining
over recent decades and was estimated at 176 (Ofu) and 177 (Olosega) in
2010 (American Samoa Government 2013, p. 8). However, because any
further loss of habitat to land-clearing will further isolate the
remaining populations of this species in American Samoa, we conclude
that habitat destruction and modification by agriculture is a current
threat to the American Samoa DPS of the friendly ground-dove that will
continue in the future.
Conservation Efforts To Reduce Habitat Destruction, Modification, or
Curtailment of Its Range
The National Park of American Samoa (NPSA) was established to
preserve and protect the tropical forest and archaeological and
cultural resources, to maintain the habitat of flying foxes, to
preserve the ecological balance of the Samoan tropical forest, and,
consistent with the preservation of these resources, to provide for the
enjoyment of the unique resources of the Samoan tropical forest by
visitors from around the world (Public Law 100-571, Public Law 100-
336). Under a 50-year lease agreement between local villages, the
American Samoa Government, and the Federal Government, approximately 73
ac (30 ha) on Ofu Island are located within park boundaries (NPSA Lease
Agreement 1993). While the majority of the park's land area on Ofu
consists of coastal and beach habitat, approximately 30 ac (12 ha) in
the vicinity of Sunuitao Peak may provide forested habitat for the
friendly ground-dove.
Summary of Factor A
Past clearing for agriculture and development has resulted in the
significant destruction and modification of coastal forest habitat for
the American Samoa DPS of the friendly ground-dove. Land-clearing for
agriculture is expected to continue in the future, but likely at a low
rate. However, the degraded and fragmented status of the remaining
habitat for the ground-dove is likely to be exacerbated by hurricanes.
Therefore, we consider habitat destruction and modification to be a
threat to this DPS.
B. Overutilization for Commercial, Recreational, Scientific, or
Educational Purposes
Pigeon-catching was a traditional practice in ancient Samoan
society (Craig 2009, p. 104). Hunting of terrestrial birds and bats in
American Samoa primarily for subsistence purposes continued until the
documented decline of wildlife populations led to the enactment of a
hunting ban and formal hunting regulations (Craig et al. 1994, pp. 345-
346). The bird species most commonly taken were the Pacific pigeon or
lupe (Ducula ducula) and the purple-capped fruit-dove or manutagi
(Ptilinopus porphyraceus). Although the many-colored fruit dove or
manuma (Ptilinopus perousii) is too rare to be sought by hunters, a few
may have been killed each year by hunters in search of the Pacific
pigeon or purple-capped fruit-dove (Craig 2009, p. 106). The incidental
shooting of the friendly ground-dove by hunters in pursuit of other
bird species (during a sanctioned hunting season; see Factor D) has the
potential to occur. Poaching is not considered a threat to the friendly
ground-dove in American Samoa (Seamon 2004a, in litt.; 2004b, in
litt.). In addition, the use of firearms on the islands of Ofu and
Olosega has rarely, if ever, been observed (Caruso 2015a, in litt.). In
summary, based on the best available scientific and commercial
information, we do not consider overutilization for commercial,
recreational, scientific, or educational purposes to be a threat to the
American Samoa DPS of the friendly ground-dove.
C. Disease or Predation
Disease
Research suggests that avian malaria may be indigenous and non-
pathogenic in American Samoa, and, therefore, is unlikely to limit
populations of the friendly ground-dove (Jarvi et al. 2003, p. 636;
Seamon 2004a, in litt.). Although other blood parasites are common in
many bird species in American Samoa, none have been reported to date in
friendly ground-dove samples (Atkinson et al. 2006, p. 232). The best
available information does not show there are other avian diseases that
may be affecting this species.
Predation
Depredation by introduced mammalian predators is the likely cause
of widespread extirpation of the friendly ground-dove throughout
portions of its range (Steadman and Freifeld 1998, p. 617; Watling
2001, p. 118). Three species of rats occur in American Samoa and are
likely to be present on the islands of Ofu and Olosega: the Polynesian
rat, Norway rat, and black rat (Atkinson 1985, p. 38; DMWR 2006, p. 22;
Caruso 2015b, in litt.). Domestic cats are widespread on Ofu and have
been observed in the proximity of areas where friendly ground-doves
have been detected (Arcilla 2015, in litt.). Feral cats are likely to
occur on Olosega because of its physical connection to Ofu.
Predation by rats is well known to have caused population decline
and extirpation in many island bird species (Atkinson 1977, p. 129;
1985, pp. 55-70; O'Donnell et al. 2015, pp. 24-26), especially species
that nest on or near the ground or in burrows (Bertram and Nagorsen
1995, pp. 6-10; Flint 1999, p. 200; Carlile et al. 2003, p. 186). For
example, black rats were responsible for the near extirpation of the
burrow-nesting Galapagos petrel on Floreana Island (Cruz and Cruz 1987,
pp. 3-13), and for the extinction of the ground-nesting Laysan rail
(Porzana palmeri), which had been translocated to Midway Atoll prior to
the loss of the Laysan population (Fisher and Baldwin 1946, p. 8). The
best available information is not specific to rat predation on the
[[Page 61593]]
American Samoa DPS of the friendly ground-dove, but the pervasive
presence of rats throughout American Samoa makes it is likely that they
play a role in limiting populations of this species.
Predation by cats has been directly responsible for the extinction
of numerous birds on oceanic islands (Medina et al. 2011, p. 6). Native
mammalian carnivores are absent from oceanic islands because of their
low dispersal ability, but once introduced by humans, they become
significant predators on native animals such as seabirds and landbirds
that are not adapted to predation by terrestrial carnivores (Nogales et
al. 2013, p. 804; Scott et al. 1986, p. 363; Ainley et al. 1997, p. 24;
Hess and Banko 2006, in litt.). Domestic cats have been observed in
remote areas known to be frequented by ground-doves and may prey on
friendly ground-doves and other species that nest on or near the ground
(Arcilla 2015, in litt.). Therefore, the threat of predation by feral
cats could potentially have a significant influence on this species,
particularly given that the American Samoa DPS of the friendly ground-
dove population appears to be very small and limited to small areas on
the islands of Ofu and Olosega.
In summary, based on the best available scientific and commercial
information, we conclude that disease is not a factor in the continued
existence of the friendly ground-dove. Because island birds such as the
friendly ground-dove are extremely vulnerable to predation by nonnative
predators, the threat of predation by rats and feral cats is likely to
continue and is considered a threat to the continued existence of this
DPS.
D. The Inadequacy of Existing Regulatory Mechanisms
The Act requires that the Secretary assess available regulatory
mechanisms in order to determine whether existing regulatory mechanisms
may be inadequate as designed to address threats to the species being
evaluated (Factor D). Under this factor, we examine whether existing
regulatory mechanisms are inadequate to address the potential threats
to the American Samoa DPS of the friendly ground-dove discussed under
other factors. In determining whether the inadequacy of regulatory
mechanisms constitutes a threat to the friendly ground-dove, we
analyzed the existing Federal and Territorial laws and regulations that
may address the threats to this species or contain relevant protective
measures. Regulatory mechanisms, if they exist, may preclude the need
for listing if we determine that such mechanisms adequately address the
threats to the species such that listing is not warranted.
In American Samoa no existing Federal laws, treaties, or
regulations specify protection of the friendly ground-dove's habitat
from the threat of deforestation, or address the threat of predation by
nonnative mammals such as rats and feral cats. However, some existing
Territorial laws and regulations have the potential to afford the
species some protection but their implementation does not achieve that
result. The DMWR is given statutory authority to ``manage, protect,
preserve, and perpetuate marine and wildlife resources'' and to
promulgate rules and regulations to that end (American Samoa Code
Annotated (ASCA), title 24, chapter 3). This agency conducts monitoring
surveys, conservation activities, and community outreach and education
about conservation concerns. However, to our knowledge, the DMWR has
not used this authority to undertake conservation efforts for the
friendly ground-dove such as habitat protection and control of
nonnative predators such as rats and cats (DMWR 2006, pp. 79-80).
The Territorial Endangered Species Act provides for appointment of
a Commission with the authority to nominate species as either
endangered or threatened (ASCA, title 24, chapter 7). Regulations
adopted under the Coastal Management Act (ASCA Sec. 24.0501 et seq.)
also prohibit the taking of threatened or endangered species (ASAC
Sec. 26.0220.I.c). However, the ASG has not listed the friendly
ground-dove as threatened or endangered so these regulatory mechanisms
do not provide protection for this species.
Under ASCA, title 24, chapter 08 (Noxious Weeds), the Territorial
DOA has the authority to ban, confiscate, and destroy species of plants
harmful to the agricultural economy. Similarly, under ASCA, title 24,
chapter 06 (Quarantine), the director of DOA has the authority to
promulgate agriculture quarantine restrictions concerning animals.
These laws may provide some protection against the introduction of new
nonnative species that may have negative effects on the friendly
ground-dove's habitat or become predators of the species, but these
regulations do not require any measures to control invasive nonnative
plants or animals that already are established and proving harmful to
native species and their habitats (DMWR 2006, p. 80) (see Factor D for
the Pacific sheath-tailed bat, above).
As described above, the Territorial Coastal Management Act
establishes a land use permit (LUP) system for development projects and
a Project Notification Review System (PNRS) for multi-agency review and
approval of LUP applications (ASAC Sec. 26.0206). The standards and
criteria for review of LUP applications include requirements to protect
Special Management Areas (SMA), Unique Areas, and ``critical habitats''
(ASCA Sec. 24.0501 et. seq.). To date, the SMAs that have been
designated (Pago Pago Harbor, Leone Pala, and Nuuuli Pala; ASAC Sec.
26.0221), are all on Tutuila and do not provide habitat for the
friendly ground-dove, which occurs only on the islands of Ofu and
Olosega. The only Unique Area designated to date, the Ottoville
Rainforest (American Samoa Coastal Management Program 2011, p. 52),
also is on Tutuila and does not provide habitat for the friendly
ground-dove. These laws and regulations are designed to ensure that
``environmental concerns are given appropriate consideration,'' and
include provisions and requirements that could address to some degree
threats to native forest habitat required by the friendly ground-dove,
even though individual species are not named (ASAC Sec. 26.0202 et
seq.). Because the implementation of these regulations has been minimal
and review of permits is not rigorous, issuance of permits may not
provide the habitat protection necessary to provide for the
conservation of the friendly ground-dove and instead result in loss of
native habitat important to this and other species as a result of land
clearing for agriculture and development (DMWR 2006, p. 71). We
conclude that the implementation of the Coastal Management Act and its
PNRS is inadequate to address the threat of habitat destruction and
degradation to the friendly ground-dove (see Factor D for the Pacific
sheath-tailed bat for further details).
Summary of Factor D
In summary, existing Territorial laws and regulatory mechanisms
have the potential to offer some level of protection for the American
Samoa DPS of the friendly ground-dove and its habitat but are not
currently implemented in a manner that would do so. The DMWR has not
exercised its statutory authority to address threats to the ground-dove
such as predation by nonnative predators, the species is not listed
pursuant to the Territorial Endangered Species Act, and the Coastal
Management Act and its implementing regulations have the potential to
address the threat of habitat loss to deforestation more substantively,
but this law is inadequately
[[Page 61594]]
implemented. Based on the best available information, some existing
regulatory mechanisms have the potential to offer some protection of
the friendly ground-dove and its habitat, but their implementation does
not reduce or remove threats to the species such as habitat destruction
or modification or predation by nonnative species. For these reasons,
we conclude that existing regulatory mechanisms do not address the
threats to the American Samoa DPS of the friendly ground-dove.
E. Other Natural or Manmade Factors Affecting Its Continued Existence
Hurricanes
Hurricanes may cause the direct and indirect mortality of the
friendly ground-dove, as well as modify its already limited habitat
(see Factor A above). This species has likely coexisted with hurricanes
for millennia in American Samoa, and if the friendly ground-dove was
widely distributed in American Samoa, had ample habitat and sufficient
numbers, and was not under chronic pressure from anthropogenic threats
such as habitat loss and introduced predators, it might recover from
hurricane-related mortality and the temporary loss or redistribution of
resources in the wake of severe storms. However, this species' current
status in American Samoa makes it highly vulnerable to chance events,
such as hurricanes.
Low Numbers of Individuals and Populations
Species with a low total number of individuals, restricted
distributions, and small, isolated populations are often more
susceptible to extinction as a result of natural catastrophes,
demographic fluctuations, or inbreeding depression (Shaffer 1981, p.
131; see Factor E discussion for the Pacific sheath-tailed bat, above).
The American Samoa DPS of the friendly ground-dove is at risk of
extinction because of its probable low remaining number of individuals
and distribution restricted to small areas on the islands of Ofu and
Olosega, conditions that render this DPS vulnerable to the small-
population stressors listed above. These stressors include
environmental catastrophes, such as hurricanes, which could immediately
extinguish some or all of the remaining populations; demographic
stochasticity that could leave the species without sufficient males or
females to be viable; and inbreeding depression or loss of adaptive
potential that can be associated with loss of genetic diversity and
result in eventual extinction. These small-population stressors are a
threat to the American Samoa DPS of the friendly ground-dove, and this
threat is exacerbated by habitat loss and degradation (Factor A) and
predation by nonnative mammals (Factor C).
Climate Change
Our analyses under the Act include consideration of ongoing and
projected changes in climate (see Factor E discussion for the Pacific
sheath-tailed bat). The magnitude and intensity of the impacts of
global climate change and increasing temperatures on western tropical
Pacific island ecosystems are currently unknown. In addition, there are
no climate change studies that address impacts to the specific habitats
of the American Samoa DPS of the friendly ground-dove. The scientific
assessment completed by the Pacific Science Climate Science Program
provides general projections or trends for predicted changes in climate
and associated changes in ambient temperature, precipitation,
hurricanes, and sea level rise for countries in the western tropical
Pacific region including Samoa (Australian BOM and CSIRO 2011, Vol. 1
and 2; used as a proxy for American Samoa) (see Factor E discussion for
the Pacific sheath-tailed bat).
Although we do not have specific information on the impacts of
climate change to the American Samoa DPS of the friendly ground-dove,
increased ambient temperature and precipitation, increased severity of
hurricanes, and sea level rise and inundation would likely exacerbate
other threats to its habitat. Although hurricanes are part of the
natural disturbance regime in the tropical Pacific, and the friendly
ground-dove has evolved in presence of this disturbance, the projected
increase in the severity of hurricanes resulting from climate change is
expected to exacerbate the hurricane-related impacts such as habitat
destruction and modification and availability of food resources of the
friendly ground-dove, whose diet consists mainly of seeds, fruit, buds,
and young leaves and shoots (Watling 2001, p. 118). For example,
Hurricanes Heta (in January 2004) and Olaf (in February 2005) virtually
destroyed suitable habitat for the friendly ground-dove at one of the
areas on Olosega where this species was most frequently encountered;
detections of ground-doves in other, less storm-damaged areas
subsequently increased, suggesting they had moved from the area
affected by the storms (Seamon 2005, in litt.; Tulafono 2006, in
litt.). The probability of species extinction as a result of climate
change impacts increases when a species' range is restricted, its
habitat decreases, and its numbers are declining (IPCC 2007, p. 8). The
friendly ground-dove is limited by its restricted range, diminished
habitat, and small population size. Therefore, we expect the friendly
ground-dove to be particularly vulnerable to the environmental impacts
of projected changes in climate and subsequent impacts to its habitat.
Based on the above information, we conclude that habitat impacts
resulting from the effects of climate change are not a current threat
but are likely to become a threat to the American Samoa DPS of the
friendly ground-dove in the future.
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 of hurricanes and low numbers of
individuals that negatively impact the American Samoa DPS of the
friendly-ground-dove.
Proposed Determination for the American Samoa DPS of the Friendly
Ground-Dove
We have carefully assessed the best scientific and commercial
information available regarding the past, present, and future threats
to the American Samoa DPS of the friendly ground-dove. The American
Samoa DPS of the friendly ground-dove is vulnerable to extinction
because of its reduced population size and distribution, habitat loss,
and probable depredation by nonnative mammals.
The habitat of the American Samoa DPS of the friendly ground-dove
remains degraded and destroyed by past land-clearing for agriculture,
and hurricanes exacerbate the poor status of this habitat, a threat
that is likely to continue in the future (Factor A) and worsen under
the projected effects of climate change. The threat of predation by
nonnative mammals such as rats and cats is likely to continue in the
future (Factor C). Current Territorial wildlife laws and regulations do
not address the threats to this DPS (Factor D). The DPS of the friendly
ground-dove persists in low numbers of individuals and in few and
disjunct populations (Factor E), a threat that interacts
synergistically with other threats. These factors pose threats to the
American Samoa DPS of the friendly ground-dove, whether we consider
their effects individually or cumulatively. These threats will continue
in the future.
The Act defines an endangered species as any species that is ``in
danger of extinction throughout all or a
[[Page 61595]]
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 the friendly ground-dove is presently in danger of extinction
throughout its entire range based on the severity and immediacy of
threats currently impacting the species.
Therefore, on the basis of the best available scientific and
commercial information, we propose listing the American Samoa DPS of
the friendly ground-dove as endangered in accordance with sections 3(6)
and 4(a)(1) of the Act. We find that the American Samoa DPS of the
friendly ground-dove is presently in danger of extinction throughout
its entire range based on the severity and immediacy of the ongoing and
projected threats described above. The friendly ground-dove is
restricted to the islands of Ofu and Olosega, where it exists in low
numbers and is subject to predation by nonnative animals. The ground-
dove's remaining habitat is limited and at risk from ongoing
degradation by hurricanes. Habitat loss and degradation and the
imminent threats of predation, the effects of small population size,
and stochastic events such as hurricanes render the American Samoa DPS
of the friendly ground-dove highly susceptible to extinction.
Under the Act and our implementing regulations, a species may
warrant listing if it is in danger of extinction or likely to become so
throughout all or a significant portion of its range. Because we have
determined that the DPS of the friendly ground-dove is endangered
throughout all of its range, no portion of its range can be
``significant'' for purposes of the definitions of ``endangered
species'' 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, July 1, 2014).
Snails
Eua zebrina
Eua zebrina, a tropical tree snail in the family Partulidae, occurs
solely on the islands of Tutuila and Ofu in American Samoa. Snails in
this family (which includes three genera: Eua, Partula, and Samoana)
are widely distributed throughout the high islands of Polynesia,
Melanesia, and Micronesia in the south- and west-Pacific basin (Johnson
et al. 1986a, pp. 161-177; Goodacre and Wade 2001, p. 6; Lee et al.
2014, pp. 2, 6-8). Many of the roughly 120 or more partulid species,
including Eua zebrina, are restricted to single islands or isolated
groups of islands (Kondo 1968, pp. 75-77; Cowie 1992, p. 169). The
Samoan partulid tree snails in the genera Eua and Samoana are a good
example of this endemism. Cowie's (1998) taxonomic work is the most
recent and accepted taxonomic treatment of this species.
Eua zebrina varies in color ranging from almost white to pale-
brown, to dark brown or purplish; with or without a zebra-like pattern
of flecks and lines (Cowie and Cooke 1999, pp. 29-30). Most E. zebrina
shells have transverse patterning (distinct coloration perpendicular to
whorls) with a more flared aperture (i.e., tapered or wide-rimmed shell
lip) than species of the related genus Samoana (Cowie et al. in prep.).
Adult Tutuila snail shells usually fall between 0.7 and 0.8 in (18 to
21 mm) in height and between 0.4 and 0.5 in (11 to 13 mm) in width.
The biology of Samoan partulid snails has not been extensively
studied, but there is considerable information on the partulid snails
of the Mariana Islands (Crampton 1925a, pp. 1-113; Cowie 1992, pp. 167-
191; Hopper and Smith 1992, pp. 77-85) and Society Islands (Crampton
1925b, pp. 5-35; Crampton 1932, pp. 1-194; Murray et al. 1982, pp. 316-
325; Johnson et al. 1986a, pp. 167-177; Johnson et al. 1986b, pp. 319-
327). Snails in the family Partulidae are predominantly nocturnal,
arboreal herbivores that feed mainly on partially decayed and fresh
plant material (Murray 1972 cited in Cowie 1992, p. 175; Murray et al.
1982, p. 324; Cowie 1992, pp. 167, 175; Miller 2014, pers. comm.).
Partulids are slow growing and hermaphroditic (Cowie 1992, pp. 167,
174). Eggs develop within the maternal body and hatch within or
immediately after extrusion; they may or may not receive nourishment
directly from the parent prior to extrusion (Cowie 1992, p. 174). Some
species in the family are known to be self-fertile, but most partulids
rely predominantly on out-crossing (Cowie 1992, pp. 167, 174). Adult
partulids generally live about 5 years and give birth about every 20
days, producing about 18 offspring per year (Cowie 1992, pp. 174, 179-
180).
Partulids can have a single preferred host plant or multiple host
plants, in addition to having preference toward anatomical parts of the
plant (i.e., leaves, branch, or trunk). Habitat partitioning may occur
among three partulids on Tutuila (Murray et al. 1982, pp. 317-318;
Cooke 1928, p. 6). Cooke (1928, p. 6) observed that Samoana conica and
S. abbreviata were commonly found on trunks and branches, and Eua
zebrina was commonly found on leaves, but could also be found on trunks
and branches, as well as on the ground in the leaf litter. A similar
partitioning of habitat has been reported for the Partula of the
Society Islands (Murray et al. 1982, p. 316). The snails are typically
found scattered on understory vegetation in forest with intact canopy
33 to 66 ft (10 to 20 m) above the ground (Cowie and Cook 1999, pp. 47-
49; Cowie 2001, p. 219). The importance of native forest canopy and
understory for Samoan land snails cannot be underestimated; all live
snails were found on understory vegetation beneath intact forest canopy
(Miller 1993, p. 16).
Review of long-term changes in the American Samoa land snail fauna
based on surveys from 1975 to 1998 and pre-1975 collections
characterized 3 of 12 species as being stable in numbers, with the rest
described as declining in numbers, including E. zebrina (Solem 1975, as
cited in Cowie 2001, pp. 214-216; Christensen 1980, p. 1; Miller 1993,
p. 13; Cowie 2001, p. 215). Eua zebrina was historically known only
from the island of Tutuila (Cowie and Cook 2001, p. 49), and until
1975, it was considered widespread and common (Cowie 2001, p. 215). The
large number of collections (927) of this species from Tutuila between
the 1920s and 1960s indicate this species was clearly widely
distributed and abundant; some collections included hundreds of
specimens (Cowie and Cook 2001, p. 154). In addition, the enormous
number of shells of this species used in hotel chandeliers also
suggests its previous abundance (Cowie 1993, p. 1). Then, in 1993, only
34 live individuals of E. zebrina were found at 2 of 9 sites on
Tutuila, with only shells found at 4 other sites (Miller 1993, pp. 11-
13). In a 1998 survey, E. zebrina was seen alive at 30 of 87 sites
surveyed for land snails on Tutuila, and at 1 of 58 sites surveyed in
the Manua Islands (Ofu, Olosega, and Tau), where it was observed for
the first time on Ofu (Cowie and Cook 1999, pp. 13, 22; Cowie 2001, p.
215). During the 1998 survey, 1,102 live E. zebrina were recorded on
Tutuila, and 88 live E. zebrina were recorded on Ofu (Cowie and Cook
1999, p. 30). The uneven distribution of the 1,102 live snails on
Tutuila suggest an overall decline in distribution and abundance; 479
live snails were recorded at 3 survey sites in one area, 165 live
snails were recorded at 7 survey sites, and fewer than 10 snails were
recorded at each of the remaining 20 sites (Cowie and Cook 1999, p.
30). On Tutuila, the survey sites with the highest numbers of E.
zebrina
[[Page 61596]]
(except one site, Amalau) are concentrated in the central area of the
National Park of American Samoa: Toa Ridge, Faiga Ridge, and eastwards
to the Vatia powerline trail and along Alava Ridge in these areas
(Cowie and Cook 1999, p. 30). We are unaware of any systematic surveys
conducted for E. zebrina since 1998; however, E. zebrina are still
periodically observed by American Samoan field biologists (Miles 2015c,
in litt.). Because the island of Ofu in the Manua Islands does not yet
have the predatory snail, Euglandina rosea (see Factor C. Disease or
Predation), the population of Eua zebrina on Ofu is of major
conservation significance (Cowie 2001, p. 217).
Summary of Factors Affecting Eua zebrina
A. The Present or Threatened Destruction, Modification, or Curtailment
of Its Habitat or Range
Habitat Destruction and Modification by Nonnative Plant Species
Nonnative plant species can seriously modify native habitat and
render it unsuitable for native snail species (Hadfield 1986, p. 325).
Although some Hawaiian tree snails have been recorded on nonnative
vegetation, it is more generally the case that native snails throughout
the Pacific are specialized to survive only on the native plants with
which they have evolved (Cowie 2001, p. 219). Cowie (2001, p. 219)
reported few observations of native snails, including Eua zebrina, in
disturbed habitats on Tutuila.
The native flora of the Samoan archipelago (plant species that were
present before humans arrived) consisted of approximately 550 taxa, 30
percent of which were endemic (species that occur only in the American
Samoa and Samoa) (Whistler 2002, p. 8). An additional 250 plant species
have been intentionally or accidentally introduced and have become
naturalized with 20 or more of these considered invasive or potentially
invasive in American Samoa (Whistler 2002, p. 8; Space and Flynn 2000,
pp. 23-24). Of these approximately 20 or more nonnative pest plant
species, at least 10 have altered or have the potential to alter the
habitat of the species proposed for listing as endangered or threatened
species (Atkinson and Medeiros 2006, p. 18; Craig 2009, pp. 94, 97-98;
ASCC 2010, p. 15).
Nonnative plants can degrade native habitat in Pacific island
environments by: (1) Modifying the availability of light through
alterations of the canopy structure; (2) altering soil-water regimes;
(3) modifying nutrient cycling; (4) ultimately converting native-
dominated plant communities to nonnative plant communities; and (5)
increasing the frequency of landslides and erosion (Smith 1985, pp.
217-218; Cuddihy and Stone, 1990, p. 74; Matson 1990, p. 245; D'Antonio
and Vitousek 1992, p. 73; Vitousek et al. 1997, pp. 6-9; Atkinson and
Medeiros 2006, p. 16). Nonnative plant species often exploit the
disturbance caused by other factors such as hurricanes, agriculture and
development, and feral ungulates, and thus, in combination reinforce or
exacerbate their negative impacts to native habitats. Although the
areas within the National Park of American Samoa (NPSA) on the islands
of Tutuila, Ofu, and Tau contain many areas that are relatively free of
human disturbance and alien invasion and largely represent pre-contact
vegetation, the threat of invasion and further spread by nonnative
plant species poses immense cause for concern (Atkinson and Medeiros
2006, p. 17; ASCC 2010, p. 22).
For brief descriptions of the nonnative plants that impose the
greatest negative impacts to the native habitats in American Samoa, see
the list provided in Habitat Destruction and Modification by Nonnative
Plants for the mao, above.
In summary, based on the potential invasion and habitat-modifying
impacts of nonnative plant species, habitat destruction and
modification by nonnative plant species is and will continue to be a
threat to Eua zebrina.
Habitat Destruction and Modification by Agriculture and Development
Several thousand years of subsistence agriculture and more recent
plantation agriculture has resulted in the alteration and great
reduction in area of forests at lower elevations (Whistler 1994, p. 40;
Mueller-Dombois and Fosberg 1998, p. 361). The threat of land
conversion to unsuitable habitat will accelerate if the human
population continues to grow or if the changes in the economy shift
toward commercial agriculture (DMWR 2006, p. 71). On the island of
Tutuila, agriculture and urban development covers approximately 24
percent of the island, and up to 60 percent of the island contains
slopes of less than 30 percent where additional land-clearing is
feasible (ASCC 2010, p. 13; DWMR 2006, p. 25). Farmers are increasingly
encroaching into some of the steep forested areas as a result of
suitable flat lands already being occupied with urban development and
agriculture (ASCC 2010, p. 13). Consequently, agricultural plots on
Tutuila have spread from low elevations up to middle and some high
elevations on Tutuila, significantly reducing the forest area and thus
reducing the resilience of the native forest and populations of native
snails. In addition, substantial housing increases are also projected
to occur in some rural forests along the northern coastline of Tutuila,
and in a few scattered areas near existing population bases with
established roads (Stein et al. 2014, p. 24). These areas are outside
of known snail locations within NPSA, but they do include forested
habitat where snails may occur.
The development of roads, trails, and utility corridors has also
caused habitat destruction and modification in or adjacent to existing
populations of Eua zebrina on Tutuila (Cowie and Cook 1999, pp. 3, 30).
Development and agriculture along the Alava Ridge road and in the areas
surrounding the Amalau inholding within NPSA pose a threat to
populations of E. zebrina in these areas (Whistler 1994, p. 41; Cowie
and Cook 1999, pp. 48-49). In addition, construction activities,
regular vehicular and foot trail access, and road maintenance
activities cause erosion and the increased spread of nonnative plants
resulting in further destruction or modification of habitat (Cowie and
Cook 1999, pp. 3, 47-48). However, in spite of the incidence of
encroachment by development and agriculture in certain areas, the NPSA
provides approximately 2,533 ac (1,025 ha) of forested habitat on
Tutuila that is largely protected from clearing for agriculture and
development and managed under a 50-year lease agreement with the
American Samoa Government and multiple villages (NPSA Lease Agreement
1993). In addition, areas of continuous, undisturbed native forest on
northwestern Tutuila outside of the NPSA boundaries may support
additional populations of E. zebrina, however, survey data for these
areas are lacking. In summary, agriculture and development have
contributed to habitat destruction and modification, and continue to be
a threat to E. zebrina on Tutuila. The available information does not
indicate that agriculture and development are a current threat to the
single known population of E. zebrina on Ofu. However, because the vast
majority of individuals and populations of this species occur on
Tutuila, we consider agriculture and development to be a current and
ongoing threat to E. zebrina.
Habitat Destruction or Modification by Feral Pigs
Feral pigs are known to cause deleterious impacts to ecosystem
processes and functions throughout their worldwide distribution (Aplet
et
[[Page 61597]]
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. Pigs are a
major vector for the establishment and spread of 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 serve 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,
alteration of plant nutrient status, and increasing the likelihood of
landslides (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).
Feral pigs have been present in American Samoa since antiquity
(American Samoa Historic Preservation Office 2015, in litt.). In the
past, hunting pressure kept their numbers down, however, increasing
urbanization and increasing availability of material goods has resulted
in the decline in the practice of pig hunting to almost nothing
(Whistler 1992, p. 21; 1994, p. 41). Feral pigs are moderately common
to abundant in many forested areas, where they spread invasive plants,
damage understory vegetation, and destroy riparian areas by their
feeding and wallowing behavior (DMWR 2006, p. 23; ASCC 2010, p. 15).
Feral pigs are a serious problem in the NPSA because of the damage they
cause to native vegetation through their rooting and wallowing
(Whistler 1992, p. 21; 1994, p. 41; Hoshide 1996, p. 2; Cowie and Cook
1999, p. 48; Togia pers. comm. in Loope et al. 2013, p. 321). Pig
densities have been reduced in some areas (Togia 2015, in litt.), but
without control methods that effectively reduce feral pig populations,
are likely to persist and remain high in areas that provide habitat for
E. zebrina (Hess et al. 2006, p. 53; ASCC 2010, p. 15). Based on the
reliance of E. zebrina on understory vegetation under native forest
canopy, as well as its potential to feed on the ground in the leaf
litter, rooting, wallowing, and trampling, the associated impacts to
native vegetation and soil caused by feral pigs will negatively impact
the habitat of E. zebrina and are a current threat to the species.
Conservation Efforts To Reduce Habitat Destruction, Modification, or
Curtailment of Its Range
Several programs and partnerships to address the threat of habitat
modification by nonnative plant species and feral pigs have been
established and are ongoing within areas that provide habitat for E.
zebrina (see Factor A discussion for the mao). In addition,
approximately 2,533 ac (1,025 ha) of forested habitat within the
Tutuila Unit of the NPSA are protected and managed under a 50-year
lease agreement with the American Samoa Government and multiple
villages contributing to the conservation of E. zebrina (NPSA Lease
Agreement 1993).
Summary of Factor A
In summary, based on the best available scientific and commercial
information, we consider the threats of destruction, modification, and
curtailment of the species habitat and range to be ongoing threats to
Eua zebrina. The decline of the native land snails in American Samoa
has resulted, in part, from the loss of native habitat to agriculture
and development, disturbance by feral pigs, and the establishment of
nonnative plant species; these threats are ongoing and are of moderate
influence, and are likely exacerbated by impacts to native forest
structure from hurricanes. All of the above threats are ongoing and
interact to exacerbate the negative impacts and increase the
vulnerability of extinction of E. zebrina.
B. Overutilization for Commercial, Recreational, Scientific, or
Educational Purposes
Tree snails can be found around the world in tropical and
subtropical regions and have been valued as collectibles for centuries.
For example, the endemic Hawaiian tree snails within the family
Achatinellidae were extensively collected for scientific and
recreational purposes by Europeans in the 18th to early 20th centuries
(Hadfield 1986, p. 322). During the 1800s, collectors sometimes took
more than 4,000 snails in several hours (Hadfield 1986, p. 322).
Repeated collections of hundreds to thousands of individuals may have
contributed to decline in these species by reduction of reproductive
potential (removal of breeding adults) as well as by reduction of total
numbers (Hadfield 1986, p. 327). In the Hawaiian genus Achatinella,
noted for its colorful variations, 22 species are now extinct and the
remaining 19 species endangered (Hadfield 1986, p. 320). In American
Samoa, thousands of partulid tree snail shells (mostly E. zebrina) have
been collected and used for decorative purposes (e.g., chandeliers)
(Cowie 1993, pp. 1, 9).
In general, the collection of tree snails persists to this day, and
the market for rare tree snails serves as an incentive to collect them.
A recent search of the Internet found a Web site advertising the sale
of E. zebrina as well as three other Partulid species (Conchology, Inc.
2015, in litt.). Based on the history of collection of E. zebrina, the
evidence of its sale on the Internet, and the vulnerability of the
small remaining populations of this species, we consider over-
collection to be a threat to the continued existence of E. zebrina.
C. Disease or Predation
Disease
We are not aware of any threats to Eua zebrina that would be
attributable to disease.
Predation by Nonnative Snails
At present, the major existing threat to long-term survival of the
native snail fauna in American Samoa is predation by the nonnative rosy
wolf snail (Euglandina rosea), the most commonly recommended biological
control agent of the giant African snail (Achatina fulica), which also
is an invasive nonnative species in American Samoa. In 1980, the rosy
wolf snail was released on Tutuila to control the giant African snail
(Lai and Nakahara 1980 as cited in Miller 1993, p. 9). By 1984, the
rosy wolf snail was considered to be well established on Tutuila,
having reached the mountains (Eldredge 1988, pp. 122, 124-125), and by
2001 was reported as widespread within the National Park of American
Samoa on Tutuila (Cowie and Cook 2001, pp. 156-157). While there are no
records of introduction of the rosy wolf snail to the Manua Islands
(Ofu, Olosega, and Tau), this species has been reported on Tau (Miller
1993, p. 10). The absence of the rosy wolf snail on the islands of Ofu
and Olosega is
[[Page 61598]]
significant because E. zebrina is present on Ofu (Miller 1993, p. 10,
Cowie and Cook 2001, p. 143; Cowie et al. 2003, p. 39).
Numerous studies show that the rosy wolf snail feeds on endemic
island snails and is a major agent in their declines and extinctions
(Hadfield and Mountain 1981, p. 357; Howarth 1983, p. 240, 1985, p.
161, 1991, p. 489; Clarke et al. 1984, pp. 101-103; Hadfield 1986, p.
327; Murray et al. 1988, pp. 150-153; Hadfield et al. 1993, pp. 616-
620; Cowie 2001, p. 219). Live individuals of the rosy wolf snail have
been observed within meters of partulids on Tutuila, including E.
zebrina and Samoana conica (Miller 1993, p. 10). Shells of E. zebrina
and S. conica were found on the ground at several of the locations
surveyed on Tutuila, along with numerous shells and an occasional live
individual of the rosy wolf snail (Miller 1993, pp. 13, 23-28). The
population of E. zebrina on Nuusetoga Island, a small islet off the
north shore of Tutuila, was probably isolated from an ancestral parent
population on Tutuila in prehistoric time (Miller 1993, p, 13). No live
rosy wolf snails were found on this offshore islet in 1992, and E.
zebrina on the islet were deemed safe from predatory snails at that
time (Miller 1993, p. 13). Due to the widespread presence of the rosy
wolf snail on Tutuila and the high probability of its unintentional
introduction into additional areas within the range of E. zebrina,
predation by the rosy wolf snail is a current threat to E. zebrina that
will continue into the future.
Predation by several other nonnative carnivorous snails, Gonaxis
kibweziensis, Streptostele musaecola, and Gulella bicolor, has been
suggested as a potential threat to Eua zebrina and other native land
snails. Species of Gonaxis, also widely introduced in the Pacific in
attempts to control Achatina fulica, have been implicated, though less
strongly, in contributing to the decline of native snail species in the
region (Cowie and Cook 1999, p. 46). Gonaxis kibweziensis was
introduced on Tutuila in American Samoa in 1977 (Eldredge 1988, p.
122). This species has only been reported from Tutuila (Miller 1993, p.
9, Cowie and Cook 1999, p. 36), and is not as common as the rosy wolf
snail (Miller 1993, p. 11). However, the two other predatory snails
have been recorded on the Manua Islands: S. musaecola from Tutuila,
Tau, and Ofu; and G. bicolor on Ofu (Cowie and Cook 1999, pp. 36-37).
The potential impacts of these two species on the native fauna are
unknown; both are much smaller than the rosy wolf snail and G.
kibweziensis, and were rarely observed during surveys (Cowie and Cook
1999, pp. 36-37, 46). However, Solem (1975 as cited in Miller 1993, p.
16) speculated that S. musaecola might have a role in the further
decline of native species, and Miller (1993, p. 16) considered that it
``undoubtedly had a negative impact.'' Despite the lack of current
information on the abundance of G. kibweziensis, but because of its
predatory nature and the declining trend and small remaining
populations of E. zebrina, we consider this species to be a threat to
the continued existence E. zebrina. However, because of their
previously observed low abundance and comparatively small size, and the
lack of specific information regarding their impacts to E. zebrina, we
do not consider predation by G. bicolor or S. musaecola to be threats
to the continued existence of E. zebrina.
In summary, predation by nonnative snails, especially the rosy wolf
snail, is a current threat to E. zebrina and will continue into the
future.
Predation by the New Guinea or Snail-Eating Flatworm
Predation by the nonnative New Guinea or snail-eating flatworm
(Platydemus manokwari) is a threat to E. zebrina. The extinction of
native land snails on several Pacific Islands has been attributed to
this terrestrial flatworm, native to western New Guinea (Ohbayashi et
al. 2007, p. 483; Sugiura 2010, p. 1,499). The New Guinea flatworm was
released in an unsanctioned effort to control the giant African snail
(Achatina fulica) in Samoa in the 1990s (Cowie and Cook 1999, p. 47).
In 2002, this species was likely present within the Samoan archipelago
but was not yet introduced to American Samoa (Cowie 2002, p. 18).
However, by 2004, this predatory flatworm had been found on the islands
of Tutuila and Tau (Craig 2009, p. 84).
The New Guinea flatworm has contributed to the decline of native
tree snails due to its ability to ascend into trees and bushes (Sugiura
and Yamaura 2009, p. 741). Although mostly ground-dwelling, the New
Guinea flatworm has also been observed to climb trees and feed on
partulid tree snails (Hopper and Smith 1992, p. 82). Areas with
populations of the flatworm usually lack partulid tree snails or have
declining numbers of snails (Hopper and Smith 1992, p. 82). Because E.
zebrina feeds on the ground as well as in shrubs and trees, it faces
increased risk of predation by the New Guinea flatworm (Cooke 1928, p.
6). In summary, due to the presence of the New Guinea flatworm on
Tutuila, and the high probability of its accidental introduction to the
islands of Ofu and Olosega, predation by the New Guinea flatworm is a
current threat to E. zebrina that will continue into the future.
Predation by Rats
Rats are likely 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 arboreal snails endemic to Pacific islands and can devastate
populations (Hadfield et al. 1993, p. 621). Rat predation on tree
snails has 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.). Three species of
rats are present in the American Samoa: The Polynesian rat, probably
introduced by early Polynesian colonizers, and Norway and black rats,
both introduced subsequent to western contact (Atkinson 1985, p. 38;
Cowie and Cook 1999, p. 47; DMWR 2006, p. 22). Polynesian and Norway
rats are considered abundant in American Samoa but insufficient data
exist on the populations of black rats (DMWR 2006, p. 22).
Evidence of predation by rats on E. zebrina was observed at several
locations on Tutuila (Miller 1993, pp. 13, 16). Shells of E. zebrina
were damaged in a fashion that is typical of rat predation; the shell
is missing a large piece of the body whorl or the apex (Miller 1993, p.
13). Old shells may be weathered in a similar fashion, except that the
fracture lines are not sharp and angular. Frequent evidence of
predation by rats was also observed on native land snails during
subsequent surveys (Cowie and Cook 1999, p. 47). In summary, based on
the presence of rats on Tutuila and Ofu, evidence of predation, and the
effects on rats on native land snail populations, predation by rats is
a threat to E. zebrina that is likely to continue in the future.
Conservation Efforts To Reduce Disease or Predation
We are unaware of any conservation actions planned or implemented
at this time to abate the threats of predation by rats, nonnative
snails or flatworms to E. zebrina.
Summary of Factor C
In summary, based on the best available scientific and commercial
information, we consider predation by the rosy wolf snail, Gonaxis
kibweziensis, New Guinea flatworm, and rats to be a threat to E.
zebrina that will continue in the future.
[[Page 61599]]
D. The Inadequacy of Existing Regulatory Mechanisms
The Act requires that the Secretary assess available regulatory
mechanisms in order to determine whether existing regulatory mechanisms
may be inadequate as designed to address threats to the species being
evaluated (Factor D). Under this factor, we examine whether existing
regulatory mechanisms are inadequate to address the potential threats
to E. zebrina discussed under other factors. In determining whether the
inadequacy of regulatory mechanisms constitutes a threat to E. zebrina,
we analyzed the existing Federal, Territorial, and international laws
and regulations that may address the threats to this species or contain
relevant protective measures. Regulatory mechanisms, if they exist, may
preclude the need for listing if we determine that such mechanisms
adequately address the threats to the species such that listing is not
warranted.
No existing Federal laws, treaties, or regulations specify
protection of E. zebrina's habitat from the threat of deforestation, or
address the threat of predation by nonnative species such as rats, the
rosy wolf snail, and the New Guinea flatworm. Some existing Territorial
laws and regulations have the potential to afford E. zebrina some
protection but their implementation does not achieve that result. The
DMWR is given statutory authority to ``manage, protect, preserve, and
perpetuate marine and wildlife resources'' and to promulgate rules and
regulations to that end (American Samoa Code Annotated (ASCA), title
24, chapter 3). This agency conducts monitoring surveys, conservation
activities, and community outreach and education about conservation
concerns. However, to our knowledge, the DMWR has not used this
authority to undertake conservation efforts for E. zebrina such as
habitat protection and control of nonnative molluscs and rats (DMWR
2006, pp. 79-80).
The Territorial Endangered Species Act provides for appointment of
a Commission with the authority to nominate species as either
endangered or threatened (ASCA, title 24, chapter 7). Regulations
adopted under the Coastal Management Act (ASCA Sec. 24.0501 et seq.)
also prohibit the taking of threatened or endangered species (ASAC
Sec. 26.0220.I.c). However, the ASG has not listed E. zebrina as
threatened or endangered so these regulatory mechanisms do not provide
protection for this species.
Under ASCA, title 24, chapter 08 (Noxious Weeds), the Territorial
DOA has the authority to ban, confiscate, and destroy species of plants
harmful to the agricultural economy. Similarly, under ASCA, title 24,
chapter 06 (Quarantine), the director of DOA has the authority to
promulgate agriculture quarantine restrictions concerning animals.
These laws may provide some protection against the introduction of new
nonnative species that may have negative effects on E. zebrina's
habitat or become predators of the species, but these regulations do
not require any measures to control invasive nonnative plants or
animals that already are established and proving harmful to native
species and their habitats (DMWR 2006, p. 80) (see Factor D for the
Pacific sheath-tailed bat, above).
As described above, the Territorial Coastal Management Act
establishes a land use permit (LUP) system for development projects and
a Project Notification Review System (PNRS) for multi-agency review and
approval of LUP applications (ASAC Sec. 26.0206). The standards and
criteria for review of LUP applications include requirements to protect
Special Management Areas (SMA), Unique Areas, and ``critical habitats''
(ASCA Sec. 24.0501 et seq.). To date, the SMAs that have been
designated (Pago Pago Harbor, Leone Pala, and Nuuuli Pala; ASAC Sec.
26.0221), all are in coastal and mangrove habitats on the south shore
of Tutuila that don't provide habitat for E. zebrina. The only Unique
Area designated to date is the Ottoville Rainforest (American Samoa
Coastal Management Program 2011, p. 52), also on Tutuila's south shore,
which hypothetically may provide habitat for E. zebrina, but it is a
relatively small island of native forest in the middle of the heavily
developed Tafuna Plain (Trail 1993, p. 4). These laws and regulations
are designed to ensure that ``environmental concerns are given
appropriate consideration,'' and include provisions and requirements
that could address to some degree threats to native forest habitat
required by E. zebrina on Tutuila and Ofu, even though individual
species are not named (ASAC Sec. 26.0202 et seq.). Because the
implementation of these regulations has been minimal and review of
permits is not rigorous, issuance of permits may not provide the
habitat protection necessary to provide for the conservation of E.
zebrina and instead result in loss of native habitat important to this
and other species as a result of land clearing for agriculture and
development (DMWR 2006, p. 71). We conclude that the implementation of
the Coastal Management Act and its PNRS is inadequate to address the
threat of habitat destruction and degradation to E. zebrina (see Factor
D for the Pacific sheath-tailed bat for further details).
Summary of Factor D
In summary, existing Territorial laws and regulatory mechanisms
have the potential to offer some level of protection for E. zebrina and
its habitat but are not currently implemented in a manner that would do
so. The DMWR has not exercised its statutory authority to address
threats to the ground-dove such as predation by nonnative predators,
the species is not listed pursuant to the Territorial Endangered
Species Act, and the Coastal Management Act and its implementing
regulations have the potential to address the threat of habitat loss to
deforestation more substantively, but this law is inadequately
implemented. Based on the best available information, some existing
regulatory mechanisms have the potential to offer some protection of E.
zebrina and its habitat, but their implementation does not reduce or
remove threats to the species such as habitat destruction or
modification or predation by nonnative species. For these reasons, we
conclude that existing regulatory mechanisms do not address the threats
to E. zebrina.
E. Other Natural or Manmade Factors Affecting Its Continued Existence
Hurricanes
Hurricanes are a common natural disturbance in the tropical Pacific
and have occurred in American Samoa with varying frequency and
intensity (see Factor E discussion for the Pacific sheath-tailed bat).
Hurricanes may adversely impact the habitat of E. zebrina by destroying
vegetation, opening the canopy, and thus modifying the availability of
light and moisture, and creating disturbed areas conducive to invasion
by nonnative plant species (Elmqvist et al. 1994, p. 387; Asner and
Goldstein 1997, p. 148; Harrington et al. 1997, pp. 539-540; Lugo 2008,
pp. 373-375, 386). Such impacts destroy or modify habitat elements
(e.g., stem, branch, and leaf surfaces, undisturbed ground, and leaf
litter) required to meet the snails' basic life-history requirements.
In addition, high winds and intense rains from hurricanes can also
dislodge individual snails from the leaves and branches of their host
plants and deposit them on the forest floor where they may be crushed
by falling vegetation or exposed to predation by nonnative rats and
snails (see ``Disease
[[Page 61600]]
or Predation,'' above) (Hadfield 2011, pers. comm.).
The negative impact on E. zebrina caused by hurricanes was strongly
suggested by surveys that failed to detect any snails in areas
bordering agricultural plots or in forest areas that were severely
damaged by three hurricanes (1987, 1990, and 1991) (Miller 1993, p.
16). Under natural conditions, loss of forest canopy to hurricanes did
not pose a great threat to the long-term survival of these snails
because there was enough intact forest with healthy populations of
snails that would support dispersal back into newly regrown canopy
forest. Similarly, forest damage may only be temporary and limited to
defoliation or minor canopy damage, and vary depending on the aspect of
forested areas in relation to the direction of approaching storms
(Pierson et al. 1992, pp. 15-16). In general, forests in American
Samoa, having evolved with the periodic disturbance regime of
hurricanes, show remarkable abilities for regeneration and recovery,
apart from catastrophic events (Webb et al. 2011, pp. 1,248-1,249).
Nevertheless, the destruction of native vegetation and forest
canopy, and modification of light and moisture conditions both during
and in the months and possibly years following hurricanes can
negatively impact the populations of E. zebrina. In addition, today,
the impacts of habitat loss and degradation caused by other factors
such as nonnative plant species (see ``Habitat Destruction and
Modification by Nonnative Plant Species'' above), agriculture and urban
development (see ``Habitat Destruction and Modification by Agriculture
and Development'' above) and feral pigs (see ``Habitat Destruction and
Modification by Feral Pigs''), are exacerbated by hurricanes. As snail
populations decline and become increasingly isolated, future hurricanes
are more likely to lead to the loss of populations or the extinction of
species such as this one that rely on the remaining canopy forest.
Therefore, we consider the threat of hurricanes to be a factor in the
continued existence of E. zebrina.
Low Numbers of Individuals and Populations
Species that undergo significant habitat loss and degradation and
other threats resulting in decline and range reduction are inherently
highly vulnerable to extinction resulting from localized catastrophes
such as severe storms or disease outbreaks, climate change effects, and
demographic stochasticity (Gilpin and Soul[eacute] 1986, pp. 24-34;
Pimm et al. 1988, p. 757; Mangel and Tier 1994, p. 607). Conditions
leading to this level of vulnerability are easily reached by island
species that face numerous threats such as those described above for
for E. zebrina. Small, isolated populations that are diminished by
habitat loss, predation, and other threats can exhibit reduced levels
of genetic variability, which can diminish the species' capacity to
adapt to environmental changes, thereby increasing the risk of
inbreeding depression and reducing the probability of long-term
persistence (Shaffer 1981, p. 131; Gilpin and Soul[eacute] 1986, pp.
24-34; Pimm et al. 1988, p. 757). The problems associated with small
occurrence size and vulnerability to random demographic fluctuations or
natural catastrophes are further magnified by interactions with other
threats, such as those discussed above (see Factor A, Factor B, and
Factor C, above).
We consider E. zebrina vulnerable to extinction because of threats
associated with low numbers of individuals and low numbers of
populations. This species has suffered a serious decline and is limited
by its slow reproduction and growth (Cowie and Cook 1999, p. 31).
Threats to E. zebrina include: Habitat destruction and modification by
hurricanes, agriculture and development, nonnative plant species and
feral pigs; collection and overutilization; and predation by the rosy
wolf snail, Gonaxis kibweziensis, and the New Guinea flatworm. The
effects of these threats are compounded by the current low number of
individuals and populations of E. zebrina.
Climate Change
Our analyses under the Act include consideration of ongoing and
projected changes in climate (see Factor E discussion for the Pacific
sheath-tailed bat). The magnitude and intensity of the impacts of
global climate change and increasing temperatures on western tropical
Pacific island ecosystems currently are unknown. In addition, there are
no climate change studies that address impacts to the specific habitats
of E. zebrina. The scientific assessment completed by the Pacific
Science Climate Science Program (Australian BOM and CSIRO 2011, Vol. 1
and Vol. 2) provides general projections or trends for predicted
changes in climate and associated changes in ambient temperature,
precipitation, hurricanes, and sea level rise for countries in the
western tropical Pacific region including Samoa (used as a proxy for
American Samoa) (see Factor E discussion for the Pacific sheath-tailed
bat for additional discussion).
Although we do not have specific information on the impacts of the
effects of climate change to E. zebrina, increased ambient temperature
and precipitation and increased severity of hurricanes would likely
exacerbate other threats to this species as well as provide additional
stresses on its habitat. 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). Eua zebrina is limited by its restricted range in small
areas on two islands and small total population size. Therefore, we
expect this species to be particularly vulnerable to environmental
impacts of climate change and subsequent impacts to its habitat. Based
on the above information, we conclude that habitat impacts resulting
from the effects of climate change are not a current threat but are
likely to become a threat to E. zebrina in the future.
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 of hurricanes and low numbers of
individuals that negatively impact E. zebrina.
Proposed Determination for Eua zebrina
We have carefully assessed the best scientific and commercial
information available regarding the past, present, and future threats
to E. zebrina. This endemic partulid tree snail restricted to the
islands of Tutuila and Ofu in American Samoa has declined dramatically
in abundance and is expected to continue along this declining trend in
the future.
The threat of habitat destruction and modification from agriculture
and development, nonnative plant species, and feral pigs is occurring
throughout the range of E. zebrina, and is not likely to be reduced in
the future (Factor A). The threat of overutilization for scientific and
commercial purposes has likely contributed to the historical decline of
E. zebrina, is a current threat to the species, and is likely to
continue into the future (Factor B). The threat of predation from
nonnative snails, a nonnative predatory flatworm, and rats is of the
highest magnitude, and likely to continue in the future (Factor C).
Current Territorial wildlife laws do not address the threats to the
species (Factor D). Additionally, the low numbers of individuals and
populations of E.
[[Page 61601]]
zebrina are likely to continue (Factor E), and these small isolated
populations face increased risk of extinction from stochastic events
such as hurricanes. Small population threats are compounded by the
threats of habitat destruction and modification, overutilization,
predation, and regulatory mechanisms that do not address the threats to
the species. These factors pose threats to E. zebrina whether we
consider their effects individually or cumulatively.
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 Eua zebrina is presently
in danger of extinction throughout its entire range based on the
severity and immediacy of the ongoing and projected threats described
above. The loss and degradation of its habitat, predation by nonnative
snails and flatworms, small number of individuals, limited
distribution, the effects of small population size, and stochastic
events such as hurricanes render this species in its entirety highly
susceptible to extinction as a consequence of these imminent threats.
Therefore, on the basis of the best available scientific and
commercial information, we propose listing Eua zebrina as endangered in
accordance with sections 3(6) and 4(a)(1) of the Act. We find that a
threatened species status is not appropriate for Eua zebrina because
the threats are occurring rangewide and are not localized, and because
the threats are ongoing and expected to continue into the future.
Under the Act and our implementing regulations, a species may
warrant listing if it is in danger of extinction or likely to become so
throughout all or a significant portion of its range. Because we have
determined that the snail E. zebrina is endangered throughout all of
its range, no portion of its range can be ``significant'' for purposes
of the definitions of ``endangered species'' 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, July 1, 2014).
Ostodes strigatus
Ostodes strigatus, a light tan- to cream-colored tropical ground-
dwelling snail in the family Poteriidae, is endemic to the island of
Tutuila in American Samoa (Girardi 1978, pp. 193, 214; Miller 1993, p.
7). Ostodes strigatus is a member of the superfamily Cyclophoroidea and
the family Poteriidae (= Neocyclotidae) (Cowie 1998, p. 24; Girardi
1978, p. 192; Vaught 1989, p. 16; ITIS 2015c). The family Poteriidae
consists of tropical land snails throughout Central America, the
northern end of South America, and the South Pacific. The genus Ostodes
is endemic to the Samoan archipelago (Girardi 1978, pp. 191, 242). The
defining characteristics of species within the family Poteriidae
include a pallium cavity (lung-like organ) and an operculum (a shell
lid or ``trap door'' used to close the shell aperture when the snail
withdraws inward, most commonly found in marine snails) (Girardi 1978,
pp. 214, 222-;224; Vaught 1989, p. 16; Barker 2001, pp. 15, 25).
Ostodes strigatus has a white, turbinate (depressed conical) shell
with 4 to 5 whorls and distinctive parallel ridges, reaching a size of
0.3 to 0.4 in (7 to 11 mm) in height, 0.4 to 0.5 in (9 to 12 mm) in
diameter at maturity (Girardi 1978, pp. 222-223; Abbott 1989, p. 43).
Its operculum is acutely concave to cone-shaped, with broad, irregular
spirals from center to edge (Girardi 1978, pp. 198, 213, 222-224). True
radial patterning is seldom found on the upper shell surface, and never
on the ventral surface, which is usually entirely smooth (Girardi 1978,
p. 223).
Ostodes strigatus is found on the ground in rocky areas under
relatively closed canopy with sparse understory plant coverage at
elevations below 1,280 ft (390 m) (Girardi 1978, p. 224; Miller 1993,
pp. 13, 15, 23, 24, 27). Moisture supply is the principal environmental
influence on Ostodes land snails (Girardi 1978, p. 245). The degree of
moisture retention is controlled primarily by vegetation cover, with
heavy forest retaining moisture at ground level longer than open forest
or cleared areas (Girardi 1978, p. 245). Ostodes species were collected
only in areas with heavy tree cover (Solem pers. comm. in Girardi 1978,
p. 245), but the relative importance of rainfall and soil type in
maintaining moisture supply was not assessed in these areas (Girardi
1978, p. 245). Nevertheless, relatively closed canopy or heavy tree
cover and their roles in maintaining moisture supply appears to be an
important habitat factor for O. strigatus.
Although the biology of the genus Ostodes is not well studied, and,
therefore, the exact diet is unknown, it is highly probable that O.
strigatus feeds at least in part on decaying leaf litter and fungus
(Girardi 1978, p. 242; Miller 2014, pers. comm.). The approximate age
at which these snails reach full sexual maturity is unknown (Girardi
1978, p. 194). Once they reach maturity and can successfully reproduce,
it is likely adult snails deposit their eggs into leaf litter where
they develop and hatch.
Ostodes strigatus is known only from the western portion of the
island of Tutuila in American Samoa, including the center and southeast
edge of the central plateau, and the extreme southern coast and
mountain slope near Pago Pago, with an elevation range of 60 to 390 m
(197 to 1,280 ft) (Girardi 1978, p. 224; B. P. Bishop Museum 2015, in
litt.). Until 1975, O. strigatus was considered widespread and common,
but has since declined significantly (Miller 1993, p. 15; Cowie 2001,
p. 215). In 1992, a survey of nine sites on Tutuila reported several
live individuals (and abundant empty shells) from a single site on the
western end of the island (Maloata Valley) and only shells (no live
individuals) at three sites in the central part of the island (Miller
1993, pp. 23-27). At each of the four sites where live O. strigatus or
empty shells were found, the predatory rosy wolf snail was common or
abundant (Miller 1993, p. 23). In 1998, surveys within the newly
established National Park of American Samoa (NPAS) on northern Tutuila
did not detect any live O. strigatus or shells (Cowie and Cook 2001,
pp. 143-159); however, Cowie and Cook (1999, p. 24) note that these
areas were likely outside the range of O. strigatus. We are unaware of
any surveys conducted since 1998; however, local field biologists that
frequent the forest above Maloata Valley for other biological field
work report they have not seen O. strigatus (Miles 2015c, in litt.).
Summary of Factors Affecting Ostodes strigatus
A. The Present or Threatened Destruction, Modification, or Curtailment
of Its Habitat or Range
The threats of nonnative plants, agriculture and development, and
feral pigs negatively impact the habitat of Ostodes strigatus in a
manner similar to that described for Eua zebrina (see Factor A
discussion for Eua zebrina above). In summary, based on the best
available, scientific and commercial information, we consider the
threats of destruction, modification, and curtailment of the species
habitat and range to be significant ongoing threats to Ostodes
strigatus. The decline of the native land snails in American Samoa has
resulted, in part, from the loss of native habitat to agriculture and
development, impacts to native forest structure from hurricanes, the
[[Page 61602]]
establishment of nonnative plant species, and disturbance by feral
pigs; these threats are ongoing and moderate in magnitude. All of the
above threats are ongoing and interact to exacerbate the negative
impacts and increase the vulnerability of extinction of O. strigatus.
Conservation Efforts To Reduce Habitat Destruction, Modification, or
Curtailment of Its Range
Several programs and partnerships to address the threat of habitat
modification by nonnative plant species and feral pigs have been
established and are ongoing within areas that provide habitat for O.
strigatus (see Factor A discussion for the mao). In addition,
approximately 2,533 ac (1,025 ha) of forested habitat within the
Tutuila Unit of the NPSA are protected and managed under a 50-year
lease agreement with the American Samoa Government and multiple
villages within a portion of the range of O. strigatus (NPSA Lease
Agreement 1993).
B. Overutilization for Commercial, Recreational, Scientific, or
Educational Purposes
Collection of land snail shells for commercial, scientific,
recreational, or educational purposes has had a moderate influence in
the decline of Ostodes strigatus (see Factor B discussion for Eua
zebrina). In the past, O. strigatus was collected for basic scientific
purposes such as identification and classification (Girardi 1978, pp.
193-194; B. P. Bishop Museum 2015, in litt.). Currently, low numbers
and awareness of its decline make collection for scientific or
educational purposes unlikely, but the rarity of O. strigatus does not
preclude collection for commercial purposes. In summary, based on the
best available scientific and commercial information, we do not
consider the overutilization for commercial, recreational, scientific,
or educational purposes to be a current threat to O. strigatus because,
although collection may occur, there is no evidence of commercial trade
in the species at the present time.
C. Disease or Predation
Disease
We are not aware of any threats to Ostodes strigatus that would be
attributable to disease.
Predation by Nonnative Snails
The nonnative rosy wolf snail is widespread on Tutuila and has been
shown to contribute to the decline and extinction of native land snails
(see Factor C discussion for Eua zebrina). Several live individuals and
numerous shells of the rosy wolf snail were found in the same sites in
which live individuals (one site) and numerous shells (three sites) of
O. strigatus were found (Miller 1993, pp. 23-27). Due to its widespread
presence on Tutuila, predation by the rosy wolf snail is considered a
threat to O. strigatus.
Predation by several other nonnative carnivorous snails, Gonaxis
kibweziensis, Streptostele musaecola, and Gulella bicolor, has been
suggested as a potential threat to O. strigatus and other native land
snails (see Factor C discussion for Eua zebrina). Despite the lack of
current information on the abundance of G. kibweziensis, but because of
its predatory nature and the declining trend and small remaining
populations of O. strigatus, we consider the predation by G.
kibweziensis to be a threat to O. strigatus. Because of their
previously observed low abundance, comparatively small size, and lack
of specific information regarding impacts to O. strigatus, we do not
consider predation by G. bicolor or S. musaecola as threats to O.
strigatus that will continue in the future. In summary, predation by
nonnative snails, especially the rosy wolf snail, is a current threat
to O. strigatus and will continue into the future.
Predation by New Guinea or Snail-Eating Flatworm
The nonnative New Guinea or snail-eating flatworm has been the
cause of decline and extinction of native land snails (see Factor C
discussion for Eua zebrina). This predatory flatworm is found on
Tutuila. The ground-dwelling habit of O. strigatus and its occurrence
in the leaf litter places O. strigatus at a greater risk of exposure to
the threat of predation by this terrestrial predator. In summary,
predation by P. manokwari is considered a threat to O. strigatus that
will continue in the future.
Predation by Rats
Rats are known to prey upon endemic land snails and can devastate
populations (see Factor C discussion for Eua zebrina). Three rat
species are present in American Samoa and frequent evidence of
predation by rats on the shells of native land snails was reported
during surveys (Miller 1993, p. 16; Cowie and Cook 2001; p. 47). In
summary, based on the presence of rats on Tutuila and evidence that
they prey on native snails, the threat of predation by rats is likely
to continue and is a significant factor in the continued existence of
Ostodes strigatus that will continue in the future.
Conservation Efforts To Reduce Disease or Predation
We are unaware of any conservation actions planned or implemented
at this time to abate the threats of predation by rats, nonnative
snails, or flatworms to O. strigatus.
Summary of Factor C
In summary, based on the best available scientific and commercial
information, we consider predation by the rosy wolf snail, the New
Guinea flatworm, and rats to be a threat to of O. strigatus that will
continue in the future.
D. The Inadequacy of Existing Regulatory Mechanisms
The Act requires that the Secretary assess available regulatory
mechanisms in order to determine whether existing regulatory mechanisms
may be inadequate as designed to address threats to the species being
evaluated (Factor D). Under this factor, we examine whether existing
regulatory mechanisms are inadequate to address the potential threats
to O. strigatus discussed under other factors. In determining whether
the inadequacy of regulatory mechanisms constitutes a threat to O.
strigatus, we analyzed the existing Federal and Territorial laws and
regulations that may address the threats to this species or contain
relevant protective measures. Regulatory mechanisms, if they exist, may
preclude the need for listing if we determine that such mechanisms
adequately address the threats to the species such that listing is not
warranted.
No existing Federal laws, treaties, or regulations specify
protection of the habitat of O. strigatus from the threat of
deforestation, or address the threat of predation by nonnative species
such as rats, the rosy wolf snail, and the New Guinea flatworm. Some
existing Territorial laws and regulations have the potential to afford
O. strigatus some protection but their implementation does not achieve
that result. The DMWR is given statutory authority to ``manage,
protect, preserve, and perpetuate marine and wildlife resources'' and
to promulgate rules and regulations to that end (American Samoa Code
Annotated (ASCA), title 24, chapter 3). This agency conducts monitoring
surveys, conservation activities, and community outreach and education
about conservation concerns. However, to our knowledge, the DMWR has
not used this authority to undertake conservation efforts for O.
strigatus such as habitat protection and control of nonnative molluscs
and rats (DMWR 2006, pp. 79-80).
[[Page 61603]]
The Territorial Endangered Species Act provides for appointment of
a Commission with the authority to nominate species as either
endangered or threatened (ASCA, title 24, chapter 7). Regulations
adopted under the Coastal Management Act (ASCA Sec. 24.0501 et seq.)
also prohibit the taking of threatened or endangered species (ASAC
Sec. 26.0220.I.c). However, the ASG has not listed O. strigatus as
threatened or endangered so these regulatory mechanisms do not provide
protection for this species.
Under ASCA, title 24, chapter 08 (Noxious Weeds), the Territorial
DOA has the authority to ban, confiscate, and destroy species of plants
harmful to the agricultural economy. Similarly, under ASCA, title 24,
chapter 06 (Quarantine), the director of DOA has the authority to
promulgate agriculture quarantine restrictions concerning animals.
These laws may provide some protection against the introduction of new
nonnative species that may have negative effects on the habitat of O.
strigatus or become predators of the species, but these regulations do
not require any measures to control invasive nonnative plants or
animals that already are established and proving harmful to native
species and their habitats (DMWR 2006, p. 80) (see Factor D for the
Pacific sheath-tailed bat, above).
As described above, The Territorial Coastal Management Act
establishes a land use permit (LUP) system for development projects and
a Project Notification Review System (PNRS) for multi-agency review and
approval of LUP applications (ASAC Sec. 26.0206). The standards and
criteria for review of LUP applications include requirements to protect
Special Management Areas (SMA), Unique Areas, and ``critical habitats''
(ASCA Sec. 24.0501 et. seq.). To date, the SMAs that have been
designated (Pago Pago Harbor, Leone Pala, and Nuuuli Pala; ASAC Sec.
26.0221), all are in coastal and mangrove habitats on the south shore
of Tutuila that don't provide habitat for O. strigatus, which is known
only from the interior western portion of the island. The only Unique
Area designated to date is the Ottoville Rainforest (American Samoa
Coastal Management Program 2011, p. 52), also on Tutuila's south shore,
which hypothetically may provide habitat for O. strigatus, but it is a
relatively small island of native forest in the middle of the heavily
developed Tafuna Plain (Trail 1993, p. 4), far from the areas where O.
strigatus has been recorded. These laws and regulations are designed to
ensure that ``environmental concerns are given appropriate
consideration,'' and include provisions and requirements that could
address to some degree threats to native forest habitat required by O.
strigatus, even though individual species are not named (ASAC Sec.
26.0202 et seq.). Because the implementation of these regulations has
been minimal and review of permits is not rigorous, issuance of permits
may not provide the habitat protection necessary to provide for the
conservation of O. strigatus and instead result in loss of native
habitat important to this and other species as a result of land
clearing for agriculture and development (DMWR 2006, p. 71). We
conclude that the implementation of the Coastal Management Act and its
PNRS is inadequate to address the threat of habitat destruction and
degradation to O. strigatus (see Factor D for the Pacific sheath-tailed
bat for further details).
Summary of Factor D
In summary, existing Territorial laws and regulatory mechanisms
have the potential to offer some level of protection for O. strigatus
and its habitat but are not currently implemented in a manner that
would do so. The DMWR has not exercised its statutory authority to
address threats to the ground-dove such as predation by nonnative
predators, the species is not listed pursuant to the Territorial
Endangered Species Act, and the Coastal Management Act and its
implementing regulations have the potential to address the threat of
habitat loss to deforestation more substantively, but this law is
inadequately implemented. Based on the best available information, some
existing regulatory mechanisms have the potential to offer some
protection of O. strigatus and its habitat, but their implementation
does not reduce or remove threats to the species such as habitat
destruction or modification or predation by nonnative species. For
these reasons, we conclude that existing regulatory mechanisms do not
address the threats to O. strigatus.
E. Other Natural or Manmade Factors Affecting Its Continued Existence
Low Numbers of Individuals and Populations
Species with low numbers of individuals, restricted distributions,
and small, isolated populations are often more susceptible to
extinction as a result of reduced levels of genetic variation,
inbreeding depression, reproduced reproductive vigor, random
demographic fluctuations, and natural catastrophes such as hurricanes
(see Factor E discussion for Eua zebrina, above). The problems
associated with small occurrence size and vulnerability to random
demographic fluctuations or natural catastrophes such as severe storms
or hurricanes are further magnified by interactions with other threats,
such as those discussed above (see Factor A, Factor B, and Factor C,
above).
We consider O. strigatus to be vulnerable to extinction due to
impacts associated with low numbers of individuals and low numbers of
populations because this species has suffered a serious decline in
numbers and has not been observed in recent years (Miller 1993, pp. 23-
27). Threats to O. strigatus include: Habitat destruction and
modification by hurricanes, agriculture and development, nonnative
plant species and feral pigs; and predation by the rosy wolf snail,
Gonaxis kibweziensis, and the New Guinea flatworm. The effects of these
threats are compounded by the current low number of individuals and
populations of O. strigatus.
Climate Change
We do not have specific information on the impacts of the effects
of climate change to O. strigatus, and our evaluation of the impacts of
climate change to this species is the same as that for E. zebrina,
above (and see Factor E discussion for the Pacific sheath-tailed bat).
Increased ambient temperature and precipitation and increased severity
of hurricanes would likely exacerbate other threats to this species as
well as provide additional stresses on its habitat. 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). Ostodes strigatus is limited by its
restricted range in one portion of Tutuila and small population size.
Therefore, we expect this species to be particularly vulnerable to
environmental impacts of climate change and subsequent impacts to its
habitat. We conclude that habitat impacts resulting from the effects of
climate change are not a current threat but are likely to become a
threat to O. strigatus in the future (see Factor E discussion for E.
zebrina, 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 of hurricanes and low numbers of
individuals that negatively impact O. strigatus.
[[Page 61604]]
Proposed Determination for Ostodes strigatus
We have carefully assessed the best scientific and commercial
information available regarding the past, present, and future threats
to Ostodes strigatus. Observations of live individuals at a single
location on western Tutuila more than 20 years ago suggest that this
species has undergone a significant reduction in its range and numbers.
The threat of habitat destruction and modification from agriculture
and development, hurricanes, nonnative plant species, and feral pigs is
occurring throughout the range of O. strigatus and is not likely to be
reduced in the future. The impacts from these threats are cumulatively
of high magnitude (Factor A). The threat of predation from nonnative
snails, rats, and the nonnative predatory flatworm is of the highest
magnitude, and likely to continue in the future (Factor C). Current
Territorial wildlife laws do not address the threats to the species
(Factor D). Additionally, the low numbers of individuals and
populations of O. strigatus, i.e., the possible occurrence of this
species restricted to a single locality where it was observed more than
20 years ago, is likely to continue (Factor E) and is compounded by the
threats of habitat destruction and modification and predation. These
factors pose threats to O. strigatus whether we consider their effects
individually or cumulatively. These threats will continue in the
future.
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 Ostodes strigatus is
presently in danger of extinction throughout its entire range based on
the severity and immediacy of the ongoing and projected threats
described above. The loss and degradation of its habitat, predation by
nonnative snails and flatworms, small number of individuals, limited
distribution, the effects of small population size, and stochastic
events such as hurricanes render this species in its entirety highly
susceptible to extinction as a consequence of these imminent threats.
Therefore, on the basis of the best available scientific and
commercial information, we propose listing Ostodes strigatus as
endangered in accordance with sections 3(6) and 4(a)(1) of the Act. We
find that a threatened species status is not appropriate for O.
strigatus because the threats are occurring rangewide and are not
localized, and because the threats are ongoing and expected to continue
into the future.
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 the
snail O. strigatus is endangered throughout all of its range, no
portion of its range can be ``significant'' for purposes of the
definitions of ``endangered species'' 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, July 1,
2014).
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, Territorial, and local agencies,
private organizations, and individuals. The Act encourages cooperation
with the States 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' 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 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, Tribes, 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.
If these species are listed, 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, U.S. Territory of American Samoa
would be eligible for Federal funds to implement management actions
that promote the protection or recovery of these species. Information
on our grant programs that are available to aid species recovery can be
found at: http://www.fws.gov/grants.
Although these species are only proposed for listing under the Act
at this time, please let us know if you are interested in participating
in recovery efforts for these 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
[[Page 61605]]
planning purposes (see FOR FURTHER INFORMATION CONTACT).
Regulatory Provisions
Section 7(a) of the Act requires Federal agencies to evaluate their
actions with respect to any species that is proposed or 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 species proposed for listing or result in
destruction or adverse modification of proposed 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.
The Act and its implementing regulations set forth a series of
general prohibitions and exceptions that apply to all endangered
wildlife. The prohibitions of section 9(a)(1) of the Act, codified at
50 CFR 17.21 for endangered wildlife, 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) any such species
within the United States or the territorial sea of the United States or
upon the high seas; to import into or export from the United States any
such species; to deliver, receive, carry, transport, or ship in
interstate or foreign commerce, by any means whatsoever and in the
course of commercial activity any such species; or sell or offer for
sale in interstate or foreign commerce any such species. In addition,
prohibitions of section 9(a)(1) of the Act make it unlawful to possess,
sell, deliver, carry, transport, or ship, by any means whatsoever, any
such species taken in violation of the Act. Certain exceptions apply to
agents of the Service and State conservation agencies.
We may issue permits to carry out otherwise prohibited activities
involving endangered and threatened wildlife species under certain
circumstances. Regulations governing permits are codified at 50 CFR
17.22 for endangered species. With regard to endangered wildlife, a
permit may be issued for the following purposes: for scientific
purposes, to enhance the propagation or survival of the species, or for
incidental take in connection with otherwise lawful activities.
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 proposed
listing on proposed and ongoing activities within the range of species
proposed for listing. The following activities could potentially result
in a violation of section 9 of the Act; this list is not comprehensive:
Activities that result in take of any of the five species in
American Samoa by causing significant habitat modification or
degradation such that it causes actual injury by significantly
impairing essential behaviors. This may include, but is not limited to,
introduction of nonnative species in American Samoa that compete with
or prey upon the species or the unauthorized release in the territory
of biological control agents that attack any life-stage of these
species.
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).
Critical Habitat
Section 3(5)(A) of the Act defines critical habitat as (i) the
specific areas within the geographical area occupied by the species, at
the time it is listed . . . on which are found those physical or
biological features (I) essential to the conservation of the species
and (II) which may require special management considerations or
protection; and (ii) specific areas outside the geographical area
occupied by the species at the time it is listed upon a determination
by the Secretary that such areas are essential for the conservation of
the species. Section 3(3) of the Act defines conservation as to use and
the use of all methods and procedures which are necessary to bring any
endangered species or threatened species to the point at which the
measures provided pursuant to the Act are no longer necessary.
Section 4(a)(3) of the Act, as amended, and implementing
regulations (50 CFR 424.12), require that, to the maximum extent
prudent and determinable, the Secretary will designate critical habitat
at the time the species is determined to be an endangered or threatened
species. Our regulations (50 CFR 424.12(a)(1)) state that the
designation of critical habitat is not prudent when one or both of the
following situations exist:
(1) The species is threatened by taking or other human activity,
and identification of critical habitat can be expected to increase the
degree of threat to the species, or
(2) Such designation of critical habitat would not be beneficial to
the species.
Besides the potential for unpermitted collection of the snails Eua
zebrina and Ostodes strigatus by hobbyists, we do not know of any
imminent threat of take attributed to collection or vandalism under
Factor B for these plant and animal species. The available information
does not indicate that identification and mapping of critical habitat
is likely to increase the threat of collection for the snails or
initiate any threat of collection or vandalism for any of the other
four species proposed for listing in this rule. Therefore, in the
absence of finding that the designation of critical habitat would
increase threats to a species, if there are any benefits to a critical
habitat designation, a finding that designation is prudent is
warranted. Here, the potential benefits of designation include: (1)
Triggering consultation under section 7 of the Act, in new areas for
actions in which there may be a Federal nexus where it would not
otherwise occur because, for example, it is unoccupied; (2) focusing
conservation activities on the most essential features and areas; (3)
providing educational benefits to State or county governments or
private entities; and (4) preventing people from causing inadvertent
harm to these species.
Because we have determined that the designation of critical habitat
will not likely increase the degree of threat to the species and may
provide some measure of benefit, we determine that
[[Page 61606]]
designation of critical habitat is prudent for all five species
proposed for listing in this rule.
Our regulations (50 CFR 424.12(a)(2)) further state that critical
habitat is not determinable when one or both of the following
situations exists: (1) Information sufficient to perform required
analysis of the impacts of the designation is lacking; or (2) the
biological needs of the species are not sufficiently well known to
permit identification of an area as critical habitat.
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 these five species' life functions is complex, and complete
data are lacking for most of them. We require additional time to
analyze the best available scientific data in order to identify
specific areas appropriate for critical habitat designation and to
prepare and process a proposed rule. Accordingly, we find designation
of critical habitat for these species in accordance with section
4(3)(A) of the Act to be ``not determinable'' at this time.
Required Determinations
Clarity of the Rule
We are required by Executive Orders 12866 and 12988 and by the
Presidential Memorandum of June 1, 1998, to write all rules in plain
language. This means that each rule we publish must:
(1) Be logically organized;
(2) Use the active voice to address readers directly;
(3) Use clear language rather than jargon;
(4) Be divided into short sections and sentences; and
(5) Use lists and tables wherever possible.
If you feel that we have not met these requirements, send us
comments by one of the methods listed in ADDRESSES. To better help us
revise the rule, your comments should be as specific as possible. For
example, you should tell us the numbers of the sections or paragraphs
that are unclearly written, which sections or sentences are too long,
the sections where you feel lists or tables would be useful, etc.
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 proposed 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.
Proposed Regulation Promulgation
Accordingly, we propose to 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 (South Pacific
subspecies)'' (Emballonura semicaudata semicaudata), in alphabetical
order under MAMMALS, to read as set forth below; and
0
b. By adding an entry for ``Ground-dove, Friendly (American Samoa
DPS)'' (Gallicolumba stairi), and ``Mao (honeyeater)'' (Gymnomyza
samoensis), in alphabetical order under BIRDS, to read as set forth
below; and
0
c. By adding an entry for Eua zebrina and Ostodes strigatus, in
alphabetical order under SNAILS, to read as set forth below:
Sec. 17.11 Endangered and threatened wildlife
* * * * *
(h) * * *
--------------------------------------------------------------------------------------------------------------------------------------------------------
Species Vertebrate population
-------------------------------------------------------------- Historic range where endangered or Status When Critical Special
Common name Scientific name threatened listed habitat rules
--------------------------------------------------------------------------------------------------------------------------------------------------------
* * * * * * *
Mammals
* * * * * * *
Bat, Pacific sheath-tailed (South Emballonura semicaudata U.S.A. (AS), Fiji, Entire................ E NA NA
Pacific subspecies) (= Peapea vai, semicaudata. Tonga, Vanuatu.
American Samoa; =Tagiti, Samoa; =
Bekabeka, Fiji).
* * * * * * *
Birds
* * * * * * *
Ground-dove, Friendly (= Tuaimeo) Gallicolumba stairi.... U.S.A. (AS)........... American Samoa........ E NA NA
(American Samoa DPS).
[[Page 61607]]
* * * * * * *
Mao (= Maomao) (honeyeater)......... Gymnomyza samoensis.... U.S.A. (AS), Samoa.... Entire................ E NA NA
* * * * * * *
Snails
* * * * * * *
Snail [no common name].............. Eua zebrina............ U.S.A. (AS)........... Entire................ E NA NA
Snail [no common name].............. Ostodes strigatus...... U.S.A. (AS)........... Entire................ E NA NA
--------------------------------------------------------------------------------------------------------------------------------------------------------
* * * * *
Dated: Sept. 16, 2015.
James W. Kurth,
Acting Director, U.S. Fish and Wildlife Service.
[FR Doc. 2015-25298 Filed 10-9-15; 8:45 am]
BILLING CODE 4333-15-P