Federal Register, Volume 83 Issue 71 (Thursday, April 12, 2018)

[Federal Register Volume 83, Number 71 (Thursday, April 12, 2018)]
[Proposed Rules]
[Pages 15900-15936]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2018-07347]

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Vol. 83

Thursday,

No. 71

April 12, 2018

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; Endangered Status for
the Island Marble Butterfly and Designation of Critical Habitat;
Proposed Rule

Federal Register / Vol. 83 , No. 71 / Thursday, April 12, 2018 /
Proposed Rules

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DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17

[Docket No. FWS-R1-ES-2016-0145; 4500030113]
RIN 1018-BB96

Endangered and Threatened Wildlife and Plants; Endangered Status
for the Island Marble Butterfly and Designation of Critical Habitat

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 the island marble butterfly (Euchloe ausonides insulanus) as an
endangered species and designate critical habitat under the Endangered
Species Act of 1973, as amended (Act). In total, approximately 812
acres (329 hectares) on the south end of San Juan Island, San Juan
County, Washington, fall within the boundaries of the proposed critical
habitat designation. If we finalize this rule as proposed, it would
extend the Act's protections to this species and its critical habitat.
The effect of this rule will be to add this species to the List of
Endangered and Threatened Wildlife and to designate critical habitat
for the island marble butterfly under the Act. We also announce the
availability of a draft economic analysis (DEA) of the proposed
designation of critical habitat for the island marble butterfly.

DATES: We will accept comments received or postmarked on or before June
11, 2018. 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 May 29, 2018.

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-2016-0145,
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-2016-0145; 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: Eric V. Rickerson, State Supervisor,
Washington Fish and Wildlife Office, 510 Desmond Drive, Suite 102,
Lacey, WA 98503; telephone 360-753-9440; or facsimile 360-534-9331. If
you use a telecommunications device for the deaf (TDD), please call the
Federal Relay Service 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.
This rule proposes the listing of the island marble butterfly
(Euchloe ausonides insulanus) as an endangered species and the
designation of critical habitat. The island marble butterfly is a
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 rule was
precluded by other higher priority listing activities. This proposed
rule reassesses all available information regarding the status of and
threats to the island marble butterfly.
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. The island marble butterfly faces the following
threats:
Habitat loss and degradation from plant succession and
invasion by plants that displace larval host plants; browsing by black-
tailed deer, European rabbits, and brown garden snails; and storm
surges;
Predation by native spiders and nonnative wasps, and
incidental predation by black-tailed deer; and
Vulnerabilities associated with small population size and
environmental and demographic stochasticity, and other chance events
that increase mortality or reduce reproductive success.
Existing regulatory mechanisms and conservation efforts do
not address the threats to the island marble butterfly to the extent
that listing is not warranted.
Under the Endangered Species Act, any species that is determined to
be an endangered or threatened species shall, to the maximum extent
prudent and determinable, have habitat designated that is considered to
be critical habitat. Section 4(b)(2) of the Endangered Species Act
states that the Secretary shall designate and make revisions to
critical habitat on the basis of the best available scientific data
after taking into consideration the economic impact, the impact on
national security, and any other relevant impact of specifying any
particular area as critical habitat. The Secretary may exclude an area
from critical habitat if he determines that the benefits of such
exclusion outweigh the benefits of specifying such area as part of the
critical habitat, unless he determines, based on the best scientific
data available, that the failure to designate such area as critical
habitat will result in the extinction of the species.
We prepared an economic analysis of the proposed designation of
critical habitat. In order to consider economic impacts, we prepared an
analysis of the economic impacts of the proposed critical habitat
designation. We hereby announce the availability of the draft economic
analysis and seek public review and comment.
Peer review. We have requested comments from independent
specialists to ensure that we based our proposed listing determination
and critical habitat designation on scientifically sound data,
assumptions, and analyses. Because we will consider all comments and
information we receive during the comment period, our final
determinations may differ from this proposal.

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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 other concerned governmental agencies,
Native American tribes, the scientific community, industry, or any
other interested parties concerning this proposed rule. We particularly
seek comments concerning:
(1) The species' biology, range, and population trends, including:
(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 the species, its
habitat, or both.
(2) Factors that may affect the continued existence of the 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 this species and existing regulations
that may be addressing those threats.
(4) Additional information concerning the historical and current
status, range, distribution, and population size of this species,
including the locations of any additional populations of this species.
(5) The reasons why we should or should not designate habitat as
``critical habitat'' under section 4 of the Act (16 U.S.C. 1531 et
seq.) including whether there are threats to the species from human
activity, the degree of which can be expected to increase due to the
designation, and whether that increase in threat outweighs the benefit
of designation such that the designation of critical habitat may not be
prudent.
(6) Specific information on:
(a) The amount and distribution of the island marble butterfly
habitat,
(b) What areas, that were occupied at the time of listing and that
contain the physical or biological features essential to the
conservation of the species, should be included in the designation and
why,
(c) Special management considerations or protection that may be
needed in critical habitat areas we are proposing, including managing
for the potential effects of climate change, and
(d) What areas not occupied at the time of listing are essential
for the conservation of the species and why.
(7) Land use designations and current or planned activities in the
subject areas and their possible impacts on proposed critical habitat.
(8) Information on the projected and reasonably likely impacts of
climate change on the island marble butterfly and proposed critical
habitat.
(9) Any probable economic, national security, or other relevant
impacts of designating any area that may be included in the final
designation, and the benefits of including or excluding areas that may
be impacted.
(10) Information on the extent to which the description of
potential economic impacts in the draft economic analysis is a
reasonable estimate of the likely economic impacts.
(11) Whether any specific areas we are proposing for critical
habitat designation should be considered for exclusion under section
4(b)(2) of the Act, and whether the benefits of potentially excluding
any specific area outweigh the benefits of including that area under
section 4(b)(2) of the Act.
(12) The likelihood of adverse social reactions to the designation
of critical habitat, as discussed in the associated documents of the
draft economic analysis, and how the consequences of such reactions, if
likely to occur, would relate to the conservation and regulatory
benefits of the proposed critical habitat designation.
(13) Whether we could improve or modify our approach to designating
critical habitat in any way to provide for greater public participation
and understanding, or to better accommodate public concerns and
comments.
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 an endangered or threatened
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 ADDRESSES. We request that you
send comments only by the one of the methods described in ADDRESSES.
If you submit information via http://www.regulations.gov, your
entire submission--including any personal identifying information--will
be posted on the website. 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.
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, Washington 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 by the date
listed above in DATES and 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.

Peer Review

In accordance with our joint policy on peer review published in the
Federal Register on July 1, 1994 (59 FR 34270), we have sought the
expert opinions of at least three appropriate and independent
specialists regarding this proposed rule. The purpose of peer review is
to ensure that we base our listing determination and critical habitat
designation on scientifically sound data, assumptions, and analyses.
The peer reviewers have expertise in the biology, habitat, and
stressors to the island marble butterfly. We have invited comment from
the peer reviewers during this public comment period; these reviews
will be available on http://www.regulations.gov under Docket No. FWS-
R1-ES-2016-0145, along with other public comments on this proposed
rule.

Previous Federal Actions

In 2006, we published a 90-day finding (71 FR 7497, February 13,
2006),

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and a 12-month not-warranted finding (71 FR 66292, November 14, 2006)
on a 2002 petition from the Xerces Society for Invertebrate
Conservation (Xerces), Center for Biological Diversity, Friends of the
San Juans, and Northwest Ecosystem Alliance. The history of that
petition and previous Federal actions in response to that petition are
summarized in our 2006 12-month finding.
On August 24, 2012, we received a second petition from Xerces dated
August 22, 2012, requesting that we emergency list the island marble
butterfly as an endangered species and that we designate critical
habitat concurrently with the listing. The petition clearly identified
itself as such and included the requisite identification information
from the petitioner, required (at that time) at 50 CFR 424.14(a).
Included in the petition was supporting information regarding the
subspecies' taxonomy, ecology, historical and current distribution,
current status, and what the petitioner identified as actual and
potential causes of decline.
On March 6, 2013, we received a notice of intent to sue from Xerces
for failure to complete the finding on the petition within 90 days. On
January 28, 2014, we entered into a settlement agreement with Xerces
stipulating that we would complete the 90-day finding before September
30, 2014. The Service published a 90-day finding in the Federal
Register on August 19, 2014 (79 FR 49045). In that finding, we
concluded that the petition presented substantial scientific
information indicating that listing the island marble butterfly may be
warranted. The settlement agreement did not specifically stipulate a
deadline for a subsequent 12-month finding.
We received a notice of intent to sue from Xerces dated September
5, 2014, stating Xerces' intent to file suit to compel the Service to
issue a finding pursuant to 16 U.S.C. 1533(b)(3)(B) (a ``12-month
finding'') as to whether the listing of the island marble butterfly is
warranted, not warranted, or warranted but precluded. We entered into a
settlement agreement with Xerces on April 6, 2015, stipulating that we
would submit a 12-month finding to the Federal Register for publication
on or before March 31, 2016. Our 12-month finding that determined
listing of the island marble butterfly was warranted but precluded by
higher priority listing actions was published in the Federal Register
on April 5, 2016 (81 FR 19527). Therefore, the island marble butterfly
was added to the list of candidate species with a listing priority
number (LPN) of 3 based on our finding that the species faces threats
that are imminent and of high magnitude.

Background

Species Information

Taxonomy and Species Description
The island marble butterfly (Euchloe ausonides insulanus) is a
subspecies of the large marble butterfly (E. ausonides) in the Pieridae
family, subfamily Pierinae, which primarily consists of yellow and
white butterflies. The island marble butterfly was formally described
in 2001, by Guppy and Shepard based on 14 specimens collected between
1859 and 1908 on or near Vancouver Island, British Columbia, Canada,
and is geographically isolated from all other E. ausonides subspecies.
The taxonomic status of the island marble butterfly is not in dispute.
Euchloe ausonides insulanus is recognized as a valid subspecies by the
Integrated Taxonomic Information System (ITIS 2015a, entire) based on
the phenotypic differences documented in Guppy and Shepard 2001. In
this document, we refer to the island marble butterfly as a species
because subspecies are treated as species for the purposes of
evaluating taxa for listing under the Act.
Island marble butterflies are approximately 1.75 inches (in) (4.5
centimeters (cm)) long (Pyle 2002, p. 142) and are differentiated from
other subspecies of the large marble butterfly by their larger size and
the expanded marbling pattern of yellow and green on the underside of
the hindwings and forewings (Guppy and Shepard 2001, p. 159). Immature
stages of the island marble butterfly have distinctly different
coloration and markings from Euchloe ausonides; specifically, the third
and fourth larval instars (instars are the larval stages between
molting events) have a white spiracular stripe (a stripe that runs
along the side of a caterpillar) subtended (bordered below) by a
yellow-green subspiracular stripe and a green-yellow ventral area,
which is different from the stripe colors and patterns described for E.
ausonides (James and Nunnallee 2011, pp. 102-103; Lambert 2011, p. 15).
The island marble butterfly is also behaviorally distinct; large marble
butterflies pupate (enter the final stage of larval development before
transforming into a butterfly) directly on their larval host plants,
whereas the island marble butterflies leave their host plants to find a
suitable pupation site up to 13 feet (ft) (4 meters (m)) away from
their larval host plants (Lambert 2011, p. 19).
Distribution
The island marble butterfly was historically known from just two
areas along the southeast coast of Vancouver Island, British Columbia,
Canada, based on 14 museum records: the Greater Victoria area at the
southern end of Vancouver Island; and near Nanaimo and on adjacent
Gabriola Island, approximately 56 miles (mi) (90 kilometers (km)) north
of Victoria. The last known specimen of the island marble butterfly
from Canada was collected in 1908 on Gabriola Island, and the species
is now considered extirpated from the province (COSEWIC 2010, p. 6).
Reasons for its disappearance from Canada are unknown. Hypotheses
include increased parasitoid loads (the number of individual deadly
parasites within an individual caterpillar) associated with the
introduction of the cabbage white butterfly (Shepard and Guppy 2001, p.
38) or heavy grazing of natural meadows by cattle and sheep, which
severely depressed its presumed larval food plant (SARA 2015).
After 90 years without a documented occurrence, the island marble
butterfly was rediscovered in 1998 on San Juan Island, San Juan County,
Washington, at least 9 mi (15 km) east of Victoria across the Haro
Strait. Subsequent surveys in suitable habitat across Southeast
Vancouver Island and the Gulf Islands in Canada (see COSEWIC 2010, p.
5), as well as the San Juan Islands and six adjacent counties in the
United States (Whatcom, Skagit, Snohomish, Jefferson, Clallam, and
Island Counties), revealed only two other occupied areas. One of these
occupied areas was centered on San Juan Island and the other on Lopez
Island, which is separated from San Juan Island by just over 0.5 mi (1
km) at its closest point. These occupied areas were eventually
determined to comprise five populations, as described in detail in our
2006 12-month finding (71 FR 66292, November 14, 2006). Since 2006, the
number and distribution of populations has declined. Four of the five
populations that once spanned San Juan and Lopez Islands have not been
detected in recent years, and the species is now observed only in a
single area centered on American Camp, a part of San Juan Island
National Historical Park that is managed by the National Park Service
(NPS). The island marble butterfly likely also uses the lands adjoining
or near American Camp, as there have been at least two observations of
island marble butterflies flying along the boundaries of these

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adjoining lands in 2015 (Potter 2015a, in litt.).
No current records exist of any life-history stage of the island
marble butterfly except at or near American Camp at San Juan Island
National Historical Park. Therefore, we consider only American Camp and
the immediately adjacent areas to be occupied at the time of this
proposed listing. However, because of the island marble butterfly's
cryptic nature and its dispersal ability, its distribution is somewhat
uncertain, and we seek any new information regarding the island marble
butterfly's distribution (see Information Requested, above).
Survey Effort
Extensive surveys have been conducted in British Columbia, Canada,
since 2001, with an estimated 500 survey hours conducted by
professional surveyors and 2,000 survey hours by volunteer butterfly
enthusiasts (COSEWIC 2010, p. v). During these surveys, neither the
island marble butterfly nor suitable habitat was detected (COSEWIC
2010, p. vi). The species has been considered extirpated in British
Columbia since 1910, and was formally designated extirpated in 1999 by
the Canadian Government (COSEWIC 2000, p. iii).
In the United States, surveys for the island marble butterfly have
also been extensive. In 2005 and 2006, we partnered with NPS,
Washington Department of Fish and Wildlife (WDFW), Washington
Department of Natural Resources (WDNR), the University of Washington,
and the Xerces Society to survey for the presence of the island marble
butterfly during the adult flight period (when eggs are laid and larvae
are active; early April-late June). Qualified surveyors conducted
approximately 335 individual surveys at more than 160 sites in
potentially suitable habitat across 6 counties (Clallam, Jefferson,
Island, San Juan, Skagit, and Whatcom) and on 16 islands (Miskelly and
Potter 2005, pp. 5, 7-16; Miskelly and Fleckenstein 2007, pp. 4, 10-
19). Outside of American Camp, sites were defined primarily by
ownership, although some exceptionally large sites were subdivided and
received unique site names. All surveys followed a set of standardized
protocols to ensure they were conducted when butterflies had the
highest likelihood of being detected (see Miskelly and Potter 2005, p.
4). Island marble butterflies were considered present at sites where
eggs, larvae, or adults of the species were detected. These surveys
documented five populations distributed across San Juan and Lopez
Islands, including the single population persisting today centered on
American Camp (Miskelly and Fleckenstein 2007, pp. 4-5).
Annual surveys conducted outside of American Camp from 2007-2012
focused on areas with suitable habitat on San Juan and Lopez Islands.
These surveys generally included previously occupied sites, when
accessible, in order to document whether or not island marble
butterflies persisted at the sites where they were detected in 2005 and
2006. After years of observing a rangewide decline in available island
marble butterfly habitat and dwindling island marble butterfly
detections, WDFW determined that there was not enough suitable habitat
remaining outside of American Camp to warrant continued widespread
survey efforts on San Juan and Lopez Islands. Therefore, surveys in
2013 and 2014 focused solely on assisting with monitoring at American
Camp and surveying lands directly adjacent to the park (Potter 2015a in
litt.). Surveys to monitor the status of the population centered on
American Camp have been conducted annually from 2004 to 2015, although
the effort has varied through time (see ``Abundance,'' below, for
additional information).
In 2015, in addition to annual population monitoring at American
Camp, the Service funded an extensive survey of sites on San Juan
Island outside of American Camp. Areas surveyed included those sites
where island marble butterflies had previously been detected, as well
as areas with suitable habitat with no prior detections. Researchers
conducted 134 individual surveys at a total of 48 sites, including 24
sites where the island marble butterfly had been previously documented.
The survey yielded no detections of the island marble butterfly outside
of American Camp.
Multiple years of extensive surveys conducted across formerly
occupied sites have failed to detect the species. However, it is
possible that the island marble butterfly continues to exist at a
handful of small isolated sites where surveyors were not granted access
or were unable to survey during suitable conditions (Miskelly and
Potter 2005, entire; Miskelly and Fleckenstein 2007, entire; Miskelly
and Potter 2009, entire; Hanson et al. 2009, entire; Hanson et al.
2010, entire; Potter et al. 2011, entire; Vernon and Weaver 2012,
entire; Weaver and Vernon 2014, entire; Potter 2015a in litt.; Vernon
2015a, entire).
Abundance
In our 2006 12-month finding, we estimated the abundance of island
marble butterflies to be ``probably less than 500 butterflies, and
possibly as low as 300 individuals'' (71 FR 66292, November 14, 2006,
p. 66295). These numbers were based on limited data, and their accuracy
is uncertain. Since 2006, there have been several efforts to either
directly estimate population size or evaluate changes in relative
abundance through time (described below). In addition, captive-rearing
and release of butterflies was initiated in 2013, and since that time,
301 captive-raised butterflies have been released at American Camp to
supplement the population (see the discussions of conservation efforts
under Factors A and C, below, for more details).
Site Occupancy--The number of sites where the island marble
butterfly is detected each year is a useful indicator of coarse-scale
changes in abundance. The island marble butterfly has been recorded at
a total of 63 individual sites since rangewide surveys began in 2005:
The species was found at 37 sites in and around American Camp and 26
sites outside of American Camp (Miskelly and Potter 2005, pp. 7-14;
Miskelly and Fleckenstein 2007, pp. 14-19; Miskelly and Potter 2009,
pp. 7-8, 10-11; Hanson et al. 2009, pp. 10-11, 24-28; Hanson et al.
2010, pp. 12-13, 26-30; Potter et al. 2011, pp. 10-23, 15-23; Potter
2012, unpublished; Potter 2013, unpublished; Vernon and Weaver 2012,
pp. 4-7; Weaver and Vernon 2014, pp. 5-8). The number of occupied sites
recorded at American Camp is somewhat confounded by changes in survey
methods and effort through time (see ``Survey Effort,'' above). We
recognize this as a potential source of uncertainty, but note that both
transect data and anecdotal observations suggest a population decline
at American Camp since monitoring began in 2004 (see Transect Counts,
below).
The largest number of concurrently occupied sites reported was 25
in 2007, 10 of which were outside of American Camp (Miskelly and Potter
2009, pp. 7-8, 10-11; Potter et al. 2011, pp. 15-16). The number of
occupied sites declined every year from 2007 to 2011, with the species
detected at only seven sites in 2011, only one of which was outside of
American Camp. In 2015, adult island marble butterflies were detected
at only four of the regularly monitored sites at American Camp, the
fewest occupied sites ever recorded, and no adults, eggs, or larvae
were detected outside of the greater American Camp area (Potter 2015a
in litt., NPS 2015a, entire; Vernon 2015b, entire), although there were
two observations of single adult butterflies flying just beyond the
boundary of the park that were not recorded in formal

[[Page 15904]]

surveys by NPS (Potter 2015a, in litt.). Island marble butterflies were
detected as eggs in six additional research plots at American Camp
(Lambert 2015d, p. 4), but none of the eggs tracked in the research
plots survived to the fifth larval instar (Lambert 2015d, p. 13). In
2016, larval habitat for the island marble butterfly at American Camp
increased substantially, and survivorship of individuals tracked from
eggs through fifth instar larvae increased from zero in 2015 to 3
percent in 2016 (Lambert 2016a, pp. 10, 21).
The reasons for the precipitous decline in the number of occupied
sites since 2005 are not known with certainty, but the near-complete
loss of habitat outside of American Camp in some years is likely a
principal cause. Habitat loss has been caused by road maintenance,
mowing, cultivation of land, intentional removal of host plants,
improperly timed restoration activities, development, landscaping, deer
browse, and livestock grazing (Miskelly and Potter 2006, p. 6; Miskelly
and Fleckenstein 2007, p. 6; Miskelly and Potter 2009, p. 9; Hanson et
al. 2009, p. 18; Hanson et al. 2010, p. 21; Potter et al. 2011, p. 13).
Transect Counts--Counts along transects can provide a measure of
relative abundance, which can be useful in assessing changes in the
population among sites and through time (Peterson 2010, pp. 12-13).
From 2004 to 2008, Lambert (2009) counted adult island marble
butterflies along transects at American Camp (14 established in 2004
and an additional 2 (for a total of 16) established in 2005), finding a
consistent and significant decline in the number of adults observed:
They counted 270 in 2004, 194 in 2005, 125 in 2006, 71 in 2007, and 63
in 2008 (Lambert 2009, p. 5). These raw counts were also translated to
relative encounter rates that account for differences in survey effort
across years, and these encounter rates also showed a marked decline
until 2016 (USFWS 2016). Four of these transects were monitored by NPS
almost continuously from 2004 to 2016 (one transect was not monitored
from 2009 to 2011), and relative encounter rates were calculated that
accounted for transect length and the number of times the transect was
surveyed each year. The relative encounter rate on these transects
declined substantially between 2004 and 2015, from almost 2 butterflies
per 100 meters surveyed in 2004 to approximately 0.3 butterflies per
100 meters in 2015 (USFWS 2016). Survey results for 2016 improved
across the three transects consistently monitored at American Camp,
with approximately 0.6 butterflies per 100 meters. While an observation
of 0.6 butterflies per 100 meters reflects an improvement from recent
years, this improvement does not reverse the overall decline observed
since monitoring began in 2004.
Mark-Release-Recapture--Mark-release-recapture (MRR) studies were
conducted at American Camp in 2008 and 2009 (and at one additional site
on San Juan Island--the Pear Point Gravel Quarry, which is no longer
occupied) (Peterson 2009, 2010; entire). These studies sought to
address several demographic questions and to assess whether transect
counts were a reliable method to estimate changes in the population
through time (Peterson 2009, p. 3). MRR population estimates were
generated for three focal areas at American Camp in 2009: The west end
of American Camp (estimated 50 individuals), American Camp below the
Redoubt (estimated 39 individuals), and the dunes at American Camp
(estimated 24 individuals). However, because American Camp was not
surveyed in its entirety, these areas represent an unquantified
fraction of the occupied habitat at American Camp; therefore, we cannot
extrapolate from this information to estimate the rangewide population.
In summary, monitoring efforts have varied since 2008, but reports
from NPS indicate an ongoing decrease in the relative abundance of the
island marble butterfly at American Camp, suggesting that total numbers
continue to decline (Vernon and Weaver 2012, pp. 5-6; Weaver and Vernon
2014, p. 6). While reliable and precise rangewide population estimates
have not been produced for this species, the available evidence
suggests that the species has a very small population that has declined
substantially since monitoring began in 2004.
Habitat
The island marble butterfly has three known host plants, all in the
mustard family (Brassicaceae). One is native, Lepidium virginicum var.
menziesii (Menzies' pepperweed), and two are nonnative: Brassica rapa
(no agreed-upon common name, but sometimes called field mustard;
hereafter referred to as field mustard for the purposes of this
document) (ITIS 2015b, entire), and Sisymbrium altissimum L. (tumble
mustard) (Miskelly 2004, pp. 33, 38; Lambert 2011, p. 2).
All three larval host plants occur in open grass- and forb-
dominated vegetation systems, but each species is most robust in one of
three specific habitat types: Menzies' pepperweed at the edge of low-
lying coastal lagoon habitat; field mustard in upland prairie habitat,
disturbed fields, and disturbed soils, including soil piles from
construction; and tumble mustard in sand dune habitat (Miskelly 2004,
p. 33; Lambert 2011, pp. 24, 121-123). While each larval host plant can
occur in the other habitat types, female island marble butterflies
select specific host plants in each of the three habitat types
referenced above, likely because certain host plants are more robust in
each habitat type during the flight season (Miskelly 2004, p. 33;
Lambert 2011, pp. 24, 41, 50, 54-57, 121-123).
Adults primarily nectar (forage) on their larval host plants
(Potter 2015e, pers. comm.), but use a variety of other nectar plants
including:
Abronia latifolia (yellow sand verbena),
Achillea millefolium (yarrow),
Amsinckia menziesii (small-flowered fiddleneck),
Cakile edentula (American sea rocket),
Cerastium arvense (field chickweed),
Erodium cicutarium (common stork's bill),
Geranium molle (dovefoot geranium),
Hypochaeris radicata (hairy cat's ear),
Lomatium utriculatum (common lomatium),
Lupinus littoralis (seashore lupine),
Myosotis discolor (common forget-me-not),
Ranunculus californicus (California buttercup),
Rubus ursinus (trailing blackberry),
Taraxacum officinale (dandelion),
Toxicoscordion venenosum (death camas, formerly known as
Zigadenus venenosus), and
Triteleia grandiflora (Howell's brodiaea, formerly
Brodiaea howellii) (Miskelly 2004, p. 33; Pyle 2004, pp. 23-26, 33;
Miskelly and Potter 2005, p. 6; Lambert 2011, p. 120; Vernon and Weaver
2012, Appendix 12; Lambert 2015a, p. 2, Lambert 2015b, in litt.). Of
these additional nectar resources, island marble butterflies are most
frequently observed feeding on yellow sand verbena, small-flowered
fiddleneck, and field chickweed (Potter 2015e, pers. comm.). Adults
primarily use low-statured, white flowering plants such as field
chickweed as mating sites (Lambert 2014b, p. 17).
Biology
The island marble butterfly life cycle comprises four distinct
developmental phases: Egg, larva, chrysalis, and butterfly. Development
from egg to chrysalis takes approximately 38 days and includes five
instars (phases of

[[Page 15905]]

larval development between molts) (Lambert 2011, p. 7). Female island
marble butterflies produce a single brood per year, and prefer to lay
their eggs individually on the unopened terminal flower buds of their
larval host plants (Lambert 2011, pp. 9, 48, 51). Gravid female
butterflies appear to select plants with many tightly grouped flower
buds over host plants with fewer buds, and they tend to avoid laying
eggs on inflorescences (flower heads) where other island marble
butterflies already have deposited eggs (Lambert 2011, p. 51). However,
the number of eggs laid on a single host plant has been observed to
vary with the density and distribution of host plants and may also be
affected by host plant robustness as well as the age of the individual
female butterfly (Parker and Courtney 1984, entire; Lambert 2011, pp.
9, 53, 54).
First instar larvae are able to feed only on tender portions of the
host plant, such as developing flower buds and new growth, and
initially move no more than a few centimeters from where they hatch
before they must feed; thus, larvae that hatch from eggs located more
than a few centimeters from a host plant's flower heads often starve
before reaching a suitable food source (Lambert 2011, pp. 12-13). The
limited locomotion of newly hatched larvae and their reliance on tender
flower buds as a food resource leads to a concentration of early-instar
larvae near the tips of their larval host plants (Lambert 2011, p. 13).
Larvae become more mobile in later instars, and their better developed
mouthparts allow them to consume older, tougher plant material.
Eventually, they may move to stems of other nearby host plants to
forage (Lambert 2011, pp. 15-17).
The fifth (last) instar larvae ``wander'' through standing
vegetation, never touching the ground, as they search for a suitable
site to pupate (form a chrysalis) (Lambert 2011, p. 20). The greatest
distance a fifth instar larva has been observed to move from its final
larval host plant was 4 meters, but few observations exist (Lambert
2011, p. 19). Fifth instar larvae select slender dry stems in the lower
canopy of moderately dense vegetation as sites for pupation and
entering diapause, a state of suspended development (Lambert 2011, p.
21).
Island marble butterflies spend the largest portion of their annual
life cycle in diapause as chrysalids. They enter diapause in midsummer
and emerge as butterflies in the spring of the following year. One
island marble chrysalis remained in diapause for 334 days (11 months)
(Lambert 2011, p. 22). Extremely low survivorship at early life-history
stages has been found in recent years (e.g., of 136 and 226 individual
eggs tracked in 2014 and 2015, respectively, zero survived to pupation;
Lambert 2015d, p. 13).
Adult island marble butterflies emerge from early April to mid-June
and live an estimated 6 to 9 days (Lambert 2011, pp. 50, 180). Males
emerge 4 to 7 days before females and patrol hillsides in search of
mates (Lambert 2011, p. 47). Male island marble butterflies are
attracted to white (ultraviolet-reflecting) objects that may resemble
females and have been observed to investigate white flowers (e.g.,
field chickweed and yarrow), white picket fences, and white lines
painted on the surface of roads (Lambert 2011, p. 47). When a male
locates a receptive female, mating may occur hundreds of meters from
the nearest larval host plant, increasing the potential extent of adult
habitat to include a varied array of plants and vegetative structure
(Lambert 2011, p. 48). Individual adult island marble butterflies
seldom disperse distances greater than 0.4 mi (0.6 km), with the
greatest documented dispersal distance being 1.2 mi (1.9 km) (Peterson
2010, pp. 3, 12).
Island marble butterflies exhibit strong site fidelity and low
dispersal capacity and, when considered on the whole, exist as a group
of spatially separated populations that interact when individual
members move from one occupied location to another (Miskelly and Potter
2009, p. 14; Lambert 2011, p. 147). For the island marble butterfly, a
population is defined as a group of occupied sites close enough for
routine genetic exchange between individuals. Thus, occupied areas
separated by distances greater than 3 mi (4.8 km) with no intervening
suitable habitat and a low likelihood of genetic exchange are
considered to be separate populations (Miskelly and Potter 2009, p.
12). Five potential populations of island marble butterflies were
identified and described in detail in the 2006 12-month finding (71 FR
66292, November 14, 2006, p. 66294): American Camp and vicinity, San
Juan Valley, Northwest San Juan Island, Central Lopez Island, and West
Central Lopez Island. As described previously, only the population at
American Camp has been detected since 2012.

Summary of Factors Affecting the Species

Section 4 of the Act (16 U.S.C. 1533) and its implementing
regulations in title 50 of the Code of Federal Regulations (50 CFR part
424) set forth the procedures for determining whether a species is an
endangered species or threatened species. The Act defines an endangered
species as ``in danger of extinction throughout all or a significant
portion of its range,'' and a threatened species as ``likely to become
an endangered species within the foreseeable future throughout all or a
significant portion of its range.'' Section 4(a)(1) requires the
Secretary to determine whether a species is an endangered species or
threatened species because of any of the following 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.
To inform the determination, we complete a status assessment in
relation to the five factors using the best available scientific and
commercial data. The status assessment provides a thorough description
and analysis of the stressors, regulatory mechanisms, and conservation
efforts affecting individuals, populations, and the species. We use the
terms ``stressor'' and ``threat'' interchangeably, along with other
similar terms, to describe anything that may have a negative effect on
the island marble butterfly. In considering what factors might
constitute threats, we must look beyond the mere exposure of the
species to the factor to determine whether the species responds to the
factor in a way that causes actual impacts to the species. If there is
exposure to a factor, but no response, or only a positive response,
that factor is not a threat. The mere identification of threats that
could affect the island marble butterfly is not sufficient to compel a
finding that listing is appropriate. Rather, we evaluate the effects of
the threats in light of the exposure, timing, and scale of the threats,
both individually and cumulatively, and any existing regulatory
mechanisms or conservation efforts that may ameliorate or exacerbate
the threats in order to determine if the species meets the definition
of an endangered species or threatened species.

Factor A. The Present or Threatened Destruction, Modification, or
Curtailment of Its Habitat or Range

Since we first analyzed stressors to the island marble butterfly's
habitat on San Juan and Lopez Islands in 2006, the species'
distribution has contracted, and it is now known only from American
Camp and the immediate vicinity on

[[Page 15906]]

San Juan (see ``Distribution,'' above). Island marble butterfly larval
habitat in natural landscapes, such as that found at American Camp, is
patchy at best, making it difficult to estimate the acreage of larval
host plants. Additionally, larval host plants are early successional
species that thrive in disturbed habitats. This can result in larval
habitat patches that may be present one year and gone the next,
depending on the level of disturbance present on the landscape.
Development
Residential development occurs on both San Juan and Lopez Islands,
primarily on private lands. Habitat loss from development affects the
island marble butterfly by reducing the availability of secure habitat
that will persist long enough for the island marble butterfly to
complete its life cycle. Development may also affect the known occupied
range of the island marble butterfly by constraining the amount of
stepping-stone habitat (patches of habitat too small to maintain an
established population, but large enough to allow for connectivity
between larger suitable patches) for dispersal. In addition, mowing or
removal of host plants (e.g., for landscaping around developments) may
also remove habitat or prevent its establishment. Because female island
marble butterflies selectively lay their eggs on the inflorescences
(flowering head) of tall, robust plants (Lambert 2011, p. 55), mowing
host plants reduces the availability of suitable oviposition (egg
laying) sites for the island marble butterfly.
Within American Camp, which is protected by NPS regulations (see
Factor D discussion, below), development is not a threat to the island
marble butterfly. However, residential development was a threat to
island marble butterfly habitat in the Cattle Point Estate and Eagle
Cove developments adjacent to American Camp. These areas accounted for
199 ac (81 ha) of island marble butterfly habitat, or 18 percent of
occupied habitat in 2006, which are now unoccupied due to habitat loss
(Potter 2015a, in litt.) associated with development (e.g., mowing,
landscaping, or removal of host plants) (Miskelly and Potter 2005, p.
6; Miskelly and Fleckenstein 2007, p. 6; Hanson et al. 2009, p. 9).
In 2006, we noted that development was occurring less rapidly in
the areas to the north and west of American Camp and on Lopez Island
where lands comprised small, rural farms with pastures and low-density
residential properties. We concluded that these areas, containing about
361 ac (146 ha), or 32 percent of the occupied habitat as of 2006,
would be managed in a way that was compatible with island marble
butterfly habitat. Since that time, the amount of farmland in San Juan
County has decreased, with the greatest loss of farmland in San Juan
County attributed to the subdivision of larger farms into smaller
parcels, which have then been developed (San Juan County Agricultural
Resources Committee 2011, p. 23). While there are no estimates of the
amount of potential habitat for the island marble butterfly lost
specifically to development, habitat loss outside of American Camp from
a variety of sources has been substantial (Miskelly and Potter 2005, p.
6; Miskelly and Fleckenstein 2007, p. 6; Miskelly and Potter 2009, p.
9; Hanson et al. 2009, pp. 18-19; Potter et al. 2011, pp. 13-14; Potter
2015a, in litt.). In addition to development of former agricultural
lands, perhaps more significant are the management practices on these
lands that effectively preclude recolonization by island marble
butterflies or create population sinks (habitat patches that attract
dispersing individuals, but do not allow them to complete their life
cycle and reproduce) (see ``Agricultural Practices,'' below). We
conclude that development has substantively contributed to the
extirpation of the island marble butterfly outside of American Camp and
remains one of several factors impeding successful recolonization of
previously occupied habitats; however, because American Camp is
protected from development by NPS regulations and is where the species
solely occurs, development is not a threat currently acting on the
remaining extant population of the species.
Road Construction
In our 2006 12-month finding (71 FR 66292, November 14, 2006), we
evaluated the impact of a planned road relocation project (Cattle Point
Road relocation project) through American Camp. Cattle Point Road is
the only point of access for residents at the southeast tip of San Juan
Island and traverses the slope of Mount Finlayson, effectively
bisecting occupied island marble butterfly habitat at the park. We
estimated that the relocation would cause temporary loss of as much as
13 ac (5 ha) of island marble butterfly habitat due to clearing and
removal of larval host plants, although there was no known breeding
habitat along the highway at that time. We concluded that the road
realignment was likely to proceed with little mortality to the island
marble butterfly.
Since 2006, we have worked closely with NPS and the Federal Highway
Administration (FHA) to ensure that project impacts were avoided or
minimized. Once the project began, in 2015, the Service, NPS, and WDFW
actively surveyed the road alignment to remove host plants before they
could attract oviposition by female island marble butterflies and to
rescue island marble butterfly eggs and larva from any larval host
plants that might have been overlooked. Island marble butterfly larval
habitat in natural landscapes, such as that found at American Camp, is
patchy at best, making it difficult to estimate the acreage of larval
host plants. While the area affected by road construction was estimated
to be 13 ac (5 ha), larval host plants did not occur in dense patches
across the construction site. As a result of these efforts, far less
suitable habitat for island marble butterflies was temporarily lost
than we anticipated in 2006, and impacts to the island marble butterfly
population were significantly reduced and potentially completely
avoided.
Habitat restoration will continue for several years; once it is
completed, we anticipate that the project will be a net benefit to the
quantity and quality of island marble butterfly habitat in the project
area due to early coordination with the FHA and the proactive
conservation measures they implemented throughout the process. These
conservation measures included the proactive removal of all larval host
plants from the footprint of the project described above (so that
butterflies do not lay eggs on plants bound to be destroyed) and the
reseeding of larval and nectar host plant species in the disturbed
areas as their revegetation strategy. These measures will both increase
the quantity and improve the quality of the habitat surrounding the
finished project. In conclusion, road construction is not currently a
threat to the island marble butterfly.
Road Maintenance
Road maintenance that destroys or negatively affects island marble
butterfly larval host plants has been a concern since 2005, when it was
documented as destroying occupied larval habitat both on San Juan and
Lopez Islands (Miskelly and Potter 2005, p. 6). For example, in 2005,
at Fisherman's Bay tombolo (a narrow beach landform that connects the
mainland to an island) on Lopez Island, road maintenance crews
deposited a quantity of sand on occupied larval host plants in an
effort to reduce the fire

[[Page 15907]]

hazard of the vegetation in preparation for a Fourth of July fireworks
display. In addition to the deposition of sand on occupied habitat, the
remainder of the site was mowed by road maintenance crews, removing all
remaining larval host plants. There were no detections of the island
marble butterfly in 2006, a single detection at the tombolo in 2007,
and none since (Miskelly and Potter 2009, p. 21; Potter et al. 2011, p.
16; Potter 2015a, in litt.).
Roadside maintenance has resulted in the destruction of suitable
habitat on Lopez Island and outside of American Camp on San Juan Island
(Miskelly and Potter 2005, p. 6). Despite changes in roadside
maintenance practices to address habitat loss, these protections were
not implemented uniformly throughout San Juan County, nor were they
implemented with the immediacy necessary to allow for widespread
persistence of island marble habitat along roadsides (Potter 2016,
pers. comm.). However, because roadside maintenance at American Camp
will be conducted in close coordination with the Service, we conclude
that whereas habitat loss associated with road maintenance activities
could be one of several factors impeding successful recolonization of
previously occupied habitats, it likely will have only minor impacts on
the island marble butterfly, given its current distribution. We do not
expect these impacts to change within American Camp in the future.
Vegetation Management
The island marble butterfly is present year round and largely
stationary while in its early developmental phases, becoming most
visible when it becomes a winged adult. The cryptic egg, larval, and
chrysalis forms make island marble butterflies vulnerable to land
management and restoration practices when those practices overlap
occupied areas. For example, in 2005, NPS conducted a prescribed fire
intended to restore native prairie, and this fire burned through the
occupied habitat during the butterfly's developmental stage and likely
killed all eggs and larvae within the affected area. Similarly, the use
of herbicides for the purpose of vegetation restoration in occupied
island marble butterfly habitat has been documented (Potter et al.
2011, p. 14). Although the direct effects of herbicides on island
marble butterflies have not been studied, indiscriminate application of
herbicides in areas occupied by eggs or larvae is likely to result in
mortality through elimination of larval host plants and primary food
resources.
Since 2010, the Service, NPS, WDFW, and other partners have
cooperated closely to achieve vegetation management and restoration
goals while also conserving the island marble butterfly and its
habitat, including nonnative larval host plants. As a result,
vegetation management has not resulted in significant harm to island
marble butterflies since 2010. The island marble butterfly is
vulnerable to vegetation management or restoration practices that are
improperly timed or poorly sited. However, this vulnerability does not,
by itself, result in impacts to the species. Currently, vegetation
management does not have a significant impact on the species because
the ongoing collaboration between cooperating partners has adequately
minimized the impacts of vegetation management actions at American
Camp.
Agricultural Practices
Agricultural activities that include tilling of the soil have been
identified as a stressor for the island marble butterfly (Potter et al.
2011, p. 14). Removal or destruction of habitat by conversion from an
agricultural condition that provides suitable habitat (e.g., old field
pasture) for island marble butterfly to an agricultural condition that
does not allow the island marble butterfly to complete its life cycle
(e.g., active cropping) has likely led to the decline of occupied
island marble butterfly habitat outside of American Camp and continues
to contribute to the curtailment of the former range of the species.
The species has not been detected since 2012 at any previously occupied
agricultural sites that have been surveyed (Potter et al. 2011, pp. 15-
16; Potter 2012, unpublished data; Potter 2013, unpublished data;
Vernon 2015b in litt., entire). In addition, no new occupied sites in
agricultural areas have been detected during surveys conducted in 2015
(Vernon 2015a, entire).
Practices on San Juan and Lopez Islands that require tilling the
soil, such as grain farming, can promote growth of the host plant field
mustard during the island marble flight period if tilling takes place
during fall and winter months (e.g., December through February)
allowing field mustard seeds in the seed bank to germinate and mature
in synchrony with the needs of the island marble butterfly. Because
cereal crops compete with field mustard, the array of established
plants can result in a diffuse number of larval host plants at a
density attractive to female island marble butterflies searching for an
oviposition site. When actively cropped agricultural areas with larval
host plants occur near occupied habitat, they can create an
``ecological trap'' if dispersing females lay eggs where the larvae do
not have adequate time to complete their life cycle before the crop is
harvested and the site is tilled for replanting the following spring
(Hanson et al. 2009, pp. 18-19; Miskelly and Potter 2009, p. 14).
Similarly, grazing can produce an ecological trap if females lay
eggs in suitable habitat that is then consumed by livestock (see
``Livestock Herbivory,'' below). However, since the 1980s, farming on
San Juan Island has trended toward small market gardens, and large,
livestock-based farms have been reduced (San Juan County Agricultural
Resources Committee 2011, p. 16). Livestock grazing does not currently
overlap any areas known to be occupied by the island marble butterfly;
thus, it is not currently a threat to the species, although it could
become a threat in the future if the island marble butterfly were to
become reestablished in areas where grazing takes place. The best
available scientific and commercial information does not indicate that
agricultural practices currently affect the island marble butterfly
because the known population occurs on NPS lands that are not managed
for agricultural use.
Plant Succession and Competition With Invasive Species
All of the known larval host plants for the island marble butterfly
are annual mustard species that are dependent on open, early-
successional conditions for germination (Lambert 2011, p. 149).
Disturbance or active management maintains these conditions; otherwise,
plant succession and invasion by weedy native and nonnative plants
greatly inhibit germination and growth of larval host plants. These
processes of vegetation change thus degrade and reduce the availability
of habitat required by the island marble butterfly to complete its life
cycle.
Succession of open, low-statured vegetation to woody plants is a
natural process in the absence of anthropogenic burning or other forms
of disturbance. The cessation of Native American burning in the mid-
1800s resulted in the loss of prairie habitat in western Washington,
including the San Juan archipelago, due to tree and shrub encroachment
(Hamman et al., 2011, p. 317). Prairies were repeatedly burned during
historical times by Native Americans for a variety of reasons, and
areas used for cultivation of food plants, such as Camassia leichtlinii
or C. quamash (great camas and common camas, respectively) may have
been

[[Page 15908]]

burned on an annual basis (Beckwith 2004, pp. 54-55; Boyd 1999, entire;
Chappell and Kagan 2001, p. 42).
Early estimates of the size of the prairie at American Camp suggest
it may have been as large as 1,500 acres (ac) (607 hectares (ha)) when
the first Europeans arrived (Douglas 1853, entire). Today, the prairie
is estimated to be 695 ac (281 ha) due, in part, to succession and
encroachment of Douglas-fir trees (Pseudotsuga menziesii) and other
woody vegetation (Rochefort et al. 2012, p. 9). Reclaiming and
maintaining open prairie habitat at American Camp requires active
management to control Douglas-fir trees and other woody species
(Rochefort et al. 2012, p. 4).
Two of the three known larval hosts for the island marble butterfly
are introduced species that self-propagate into open, disturbed areas:
Field mustard and tumble mustard. In the absence of active restoration
or disturbance, other weedy plant species, as well as woody plants and
trees, are likely to colonize the site, eventually outcompeting the
early-successional host plants. At American Camp, where remnant prairie
habitat persists, weedy species such as Elymus repens (quack grass),
Holcus lanatus (velvet grass), Cirsium arvense (Canada thistle), and
Vicia sativa (common vetch), among others, outcompete the larval host
plants in the absence of disturbance.
Competition with nonnative species also affects host plants in sand
dune habitat. The sand dunes represent a unique habitat type for the
island marble butterfly that includes open, shifting sands easily
colonized by the larval host plant, tumble mustard (Lambert 2011, p.
42). While Menzies' pepperweed and field mustard also occasionally
occur in dune habitat, tumble mustard is the host plant that occurs
there most commonly, is most robust in this habitat type, and can
create continuous stands of larval host plants under optimal conditions
(Lambert 2011, pp. 42, 65). When nonnative species such as Canada
thistle, hairy cat's ear, and Rumex acetosella (sheep sorrel) colonize
the sandy dune habitat, the dunes become increasingly stable and the
effect is a reduction in the available germination sites for tumble
mustard (Weaver and Vernon 2014, pp. 5, 9). Canada thistle has the
greatest potential to negatively affect dune habitat where it is
stabilizing the sand and facilitating establishment of grasses, which,
in turn, displace tumble mustard (Rochefort 2010, p. 28; Weaver and
Vernon 2014, p. 9).
Conditions for larval host plants continue to be degraded through
plant succession and invasion throughout the range of the island marble
butterfly. Loss of habitat conditions favorable for larval host plants,
and thus habitat loss for the island marble butterfly, occurs in at
least two of three habitat types at American Camp, the only area where
the island marble butterfly is currently known to persist (Weaver and
Vernon 2014, pp. 5, 9). Loss of potentially suitable but not currently
occupied habitat resulting from succession also occurs in any areas
outside of American Camp where these processes take place. Due to the
extremely limited numbers and range of the island marble butterfly, any
further loss of habitat may lead to further decline of the species and
preclude its establishment in new areas.
Herbivory
Herbivory by Deer: Black-tailed deer (Odocoileus hemionus
columbianus) are common in the San Juan Island archipelago. At the
single occupied site where island marble butterfly is currently known
to exist, black-tailed deer numbers appear to be increasing (Lambert
2014a, p. 3). Browsing deer prefer flowering plants when available, and
tend to select stems on the tops or sides of plants over the stems that
emerge lower on the stalk (Anderson 1994; p. 107; Lambert 2015c, in
litt., Thomas 2015, pers. obs.). Specifically, at study sites where
island marble butterflies exist, deer browse selectively on robust
larval host plants with several inflorescences of compact flower buds--
the same plant characteristics preferred by female island marble
butterflies as egg-laying sites (Lambert 2011, p. 103). The effect of
deer browse on larval host plants is three-fold. First, it destroys
suitable egg-laying habitat; second, it stimulates rapid growth of
lateral (side) stems on the plant, rendering the plant less likely to
support an individual butterfly from egg to late-instar larva; and
third, continual browsing of the flowering portion of the plant reduces
seed production, resulting in fewer larval host plants over time
(Lambert 2011, p. 10; Lambert 2014a, p. 10; Lambert 2015d, p. 17). Deer
browse, which stimulates rapid lateral stem growth, results in
increased mortality when eggs are laid on the flowers of lateral stems
on the larval host plants (Lambert 2011, p. 10). Immobile, early-instar
larvae of island marble butterfly present on these stems are left
behind as the stems grow away from them. When the larvae can no longer
access the tender tissues at the developing tips of the plant that they
require for survival, they die from starvation (Lambert 2011, p. 10,
Lambert 2015e, in litt.).
The destructive effects of deer browse on larval habitat are common
where surveys have taken place throughout the known range of the island
marble butterfly (Miskelly and Fleckenstein 2007, p. 6; Miskelly and
Potter 2009, pp. 11, 15; Hanson et al. 2009, pp. 4, 13, 19-20; Hanson
et al. 2010, pp. 21-22; Potter et al. 2011, pp. 5, 13; Lambert 2011, p.
104; Lambert 2014a, entire; Weaver and Vernon 2014, p. 10; Vernon and
Weaver 2012, p. 9; Lambert 2015d, pp. 17-18). At American Camp,
herbivory by deer has affected 95 percent of field mustard plants in
some years (Lambert 2011, p. 127). Deer exclusion fencing has been
erected to protect suitable habitat at American Camp to counteract the
impacts of deer browse, but the fencing has not been fully effective at
excluding deer, and deer have continued to consume occupied larval host
plants (see ``Habitat Conservation and Restoration,'' below).
Habitat loss attributable to herbivory by deer is ongoing and
extensive throughout the current and former range of the island marble
butterfly, and may be increasing, with substantial impacts to the
species (Lambert 2011, pp. 85-104; Lambert 2014a, p. 3; Lambert 2015d,
pp. 14-18). The effect of habitat loss due to deer herbivory is
compounded by the effect of inadvertent predation when the larval host
plants are occupied by eggs or larvae (see ``Incidental Predation''
under the Factor C discussion, below).
Herbivory by Livestock: Livestock readily consume field mustard,
which is often cultivated in pastures as a way to improve forage for
cows and sheep (Smart et al. 2004, p. 1; McCartney et al. 2009, p.
436). There is no livestock grazing at American Camp, but livestock
pastures are present on San Juan and Lopez Islands in areas that may
contain suitable habitat for dispersing island marble butterflies. When
cattle or sheep are present on lands where field mustard is grown, they
readily consume the flower heads, stems, and stalk of the plant,
destroying suitable island marble butterfly habitat (Miskelly and
Potter 2009, p. 15; Hanson et al. 2009, p. 20; Hanson et al. 2010, p.
21). Like conversion of old field pastures to active cropping,
cultivation of field mustard as a forage species for livestock
potentially creates an ecological trap for the island marble butterfly
when cultivation takes place within dispersal distance of an occupied
site, and female island marble butterflies lay eggs in a patch of field
mustard that is later consumed or trampled by livestock before any
larvae can complete their life cycle (see

[[Page 15909]]

``Incidental Predation'' under Factor C, below, for further
discussion). In conclusion, loss of potential habitat to livestock
grazing can prevent reestablishment and persistence of suitable habitat
for the species outside of American Camp. However, because livestock
grazing is not permitted on American Camp where the species occurs,
herbivory by livestock is not a threat currently acting on the
remaining population of the species.
Herbivory by Rabbits: The European rabbit, Oryctolagus cuniculus,
is a common invasive species in the San Juan Islands (Hall 1977,
entire; Burke Museum 2015). At American Camp, European rabbits have
been established for more than a century, following their introduction
to San Juan Island during the late 1800s (Couch 1929, p. 336). Grazing
by European rabbits, when they proliferate, affects both vegetative
structure and composition, reducing both the number and kind of plant
species near their warrens (network of burrows) (Eldridge and Myers
2001, pp. 329, 335). Herbivory by European rabbits negatively affects
the recruitment and establishment of larval host plants; where rabbits
occur at American Camp, few larval host plants for the island marble
butterfly persist due to the intense grazing pressure (Radmer 2015, in
litt.). When larval host plants do germinate near European rabbit
warrens, they are consumed before the plants are large enough for
female island marble butterflies to recognize and use them.
Population monitoring of European rabbits has been conducted at
American Camp from 1985 to 2015, documenting an estimated population
high of approximately 1,750 rabbits in 2006, and a low of fewer than
100 in 2012. From 2009 through 2012, the population was estimated to be
100 animals or fewer, and the condition of vegetation in the affected
area had ``changed dramatically'' with the reduction in rabbit grazing
pressure (West 2013, pp. 2, 4). The most recent population estimate, in
2015, was approximately 500 animals, indicating that the rabbit
population at American Camp is currently on the rise (West 2015, in
litt.). If European rabbits remain uncontrolled at American Camp, their
population is likely to fluctuate but continue expanding overall in the
next decade, similar to the patterns documented in the past 30 years of
monitoring data. The majority of the European rabbit population has
been, and may continue to be, centered on a single large field near the
middle of American Camp, surrounded by areas that include island marble
butterfly habitat. As their population grows, we expect the impacts of
European rabbits to expand, encroaching upon and destroying additional
island marble butterfly habitat.
Herbivory by Brown Garden Snails: The nonnative brown garden snail
(Cornu aspersum, formerly Helix aspersa) is a generalist herbivore that
has been reported to occur in great numbers in some areas where island
marble butterfly previously occurred (e.g., Pear Point Gravel Pit or
`La Farge' and San Juan Valley), where it feeds on field mustard and
tumble mustard, the two most common larval host plants for the island
marble butterfly (Hanson et al. 2010, p. 18; Potter et al. 2011, p.
13). State biologists removed hundreds of snails that were feeding on
larval host plants at Pear Point in 2010, when the island marble
butterfly still occupied this site (Potter et al. 2011, p. 13). The
brown garden snail has extremely high reproductive potential; it
matures within 2 years and can produce more than 100 eggs five or six
times each year (Vernon 2015c, p. 1). The number of brown garden snails
observed on San Juan Island has increased substantially between the
years of 2009 and 2015 (Potter et al. 2011, p. 13; Vernon 2015c in
litt., entire).
In 2015, the brown garden snail was observed in San Juan Valley, a
site formerly occupied by the island marble butterfly, and in 2016, the
brown garden snail was documented in the South Beach area at American
Camp by a Service biologist (Vernon 2015c in litt., entire; Vernon
2015a, p. 4; Reagan 2016, pers. obs.). High numbers of brown garden
snails have been documented in highly disturbed sites previously
occupied by island marble butterfly, and since our 2016 12-month
finding (81 FR 19527) was published, they have been found invading the
natural areas in American Camp currently occupied by the island marble
butterfly and its host plants (Shrum 2017, pers. comm.). This most
recent development indicates that brown garden snail is now well
established within American Camp and the habitat currently used by the
island marble butterfly, raising the likelihood that herbivory by the
brown garden snail will result in habitat loss or degradation to an
extent that can affect the butterfly's survival and reproductive
success. While there are no documented accounts of snails directly
consuming island marble butterfly eggs or larvae, the brown garden
snail poses a threat to the island marble butterfly by consuming larval
host plants, whether those plants are occupied or not. Therefore,
herbivory by brown garden snails is detrimental to the butterfly's
overall survival and reproductive success because it can both reduce
the quantity of suitable host plants available and cause incidental
mortality of individuals.
Storm Surges
The nearshore lagoon habitat for island marble butterfly is close
to sea level. Three intermittently occupied sites are in lagoons along
the northeastern edge of American Camp, where they are partially
protected from tidal surges that arrive from the west. One of these
lagoons had the highest relative encounter rate of all monitored
transects at American Camp in 2015, and raw counts at this site
represented roughly 50 percent of the adult island marble butterflies
recorded during annual monitoring for that year. Storm surges,
attributable to the combined forces of high tides and high-wind storm
events, inundate these low-lying lagoon areas intermittently, as
evidenced by the deposition of driftwood logs along the shoreline.
These events have occurred with some regularity through time, but the
most recent episodes of inundation have been particularly destructive
of nearshore island marble butterfly habitat. A storm surge event in
the winter of 2006 resulted in the deposition of gravel substrate and
driftwood over an island marble butterfly research plot where the one
native larval host plant, Menzies' pepperweed, had been established,
reducing the number of plants by more than 50 percent (Lambert 2011,
pp. 145-146). This same storm surge likely destroyed any butterflies
that were overwintering in nearshore habitat as chrysalids and had a
local population-level impact; low numbers of individual island marble
butterflies, eggs, and larvae were detected at the site for several
years following the event (Lambert 2011, p. 99; Lambert 2015f, in
litt.).
The frequency of storm surges large enough to inundate the lagoons
and destroy island marble butterfly habitat has previously been
relatively low, but since 2006, at least one storm surge event (in
2009) was strong enough to inundate the low-lying habitat (Whitman and
MacLennan 2015, in litt.). The frequency of these events is expected to
increase with sea-level rise associated with climate change (see Factor
E discussion, below). In turn, we anticipate a concomitant increase in
the potential for destruction of low-lying habitat for the island
marble butterfly--approximately 15 to 20 percent of the species'
habitat in American Camp (Lambert 2011, p. 145; Adeslman et al. 2012,
pp. 79-86; Whitman and

[[Page 15910]]

MacLennan 2015, in litt.; NOAA 2015a, entire; NOAA 2015b, entire).
The Menzies' pepperweed (the native host plant) occurs almost
exclusively in the low-lying nearshore habitat, and female island
marble butterflies have been observed to deposit eggs on only a single
species of larval host plant at any one site. (Despite close
observations of ovipositing females, researchers have not observed
females depositing eggs on more than one type of larval host plant at
any one site.) Therefore, if this habitat type is lost, an unknown
proportion of diversity--in habitat use or adaptive potential--in the
island marble butterfly could be lost as well. Furthermore, low-lying
habitat comprises an estimated 15-20 percent of habitat for the species
at American Camp, a considerable proportion of the restricted range of
the species. Due to the small size of the remaining known population of
the island marble butterfly and the importance of this low-lying
habitat demonstrated by high encounter rates during surveys, loss or
degradation of this habitat will likely lead to a further decline of
the species.
Habitat Conservation and Restoration
San Juan Island National Historical Park has been implementing
conservation measures for the island marble butterfly since shortly
after its rediscovery in 1998. From 2003 through 2006, the NPS created
experimental prairie disturbances and vegetation plots to better
understand how to manage the prairie and create island marble butterfly
habitat. This work resulted in recommendations for the best method of
reducing the cover of invasive grasses by using prescribed fire
followed by herbicide treatment (Lambert 2006, p. 110). However, the
work was not reproduced at larger scales, nor was it continued in ways
sufficient to maintain adequate habitat on the landscape over time.
In 2006, we finalized a conservation agreement with NPS for the
island marble butterfly that contained several conservation actions
that would be applied to manage habitat for the species into the
future. The agreement, which expired in September of 2016, committed
NPS to: (1) Restore native grassland ecosystem components of the
landscape at American Camp through active management, including the use
of prescribed fire, and create a mosaic of early-successional
conditions by restoring up to 10 acres per year; and (2) avoid impacts
to island marble butterflies, eggs, larvae, and host plants during the
implementation of all NPS management actions by working in habitat that
was not occupied by island marble butterflies. All vegetation treatment
would be conducted in the fall after the island marble butterfly has
entered diapause. NPS is working with the Service to extend the
conservation agreement. We expect the history of collaborative
conservation of the island marble butterfly by NPS and the Service to
continue for the foreseeable future.
From 2007 through 2011, NPS managed encroaching plant species using
multiple methods to open up areas where larval host plants could
naturally germinate from the seed bank (NPS 2013, pp. 7-11). NPS also
planted more than 100,000 native grass plugs in mechanically treated
areas (NPS 2013, p. 7), which improved the native composition of the
prairie grassland features but did not result in increased cover of the
larval host plants needed to support the island marble butterfly. The
Service continued to work collaboratively with NPS to develop annual
work plans each year from 2013 through 2016; these work plans are
addenda to the 2006 conservation agreement for the island marble
butterfly. The goals and actions identified in the work plans have
changed, sometimes annually, in response to new information, adaptive
management needs, available funding, and other concerns. The 2013-2016
work plans identified and enacted several conservation actions to
address threats related to the destruction, modification, and
curtailment of island marble butterfly habitat at American Camp.
Prescribed fire, deer fencing of essential habitat, management of
invasive species, and experimental habitat restoration were all
implemented per annual work plans during this period.
These work plans initially included the use of prescribed fire in
small blocks (up to one acre) to disturb grassland habitat in an effort
to encourage larval host plant patches to establish from the seed bank.
These prescribed fire events resulted in very low germination of the
larval host plants, leading NPS to conclude that few larval host plant
seeds persist in the seed bank. In response, later annual work plans
recommended seeding the larval host plant species after a prescribed
burn. The 2016 annual work plan also included recommendations for the
development of novel methods for creating island marble butterfly
habitat. Despite the temporary lapse of the conservation agreement with
NPS, the Service and NPS continue to work together to conserve the
island marble butterfly and a work plan for 2017 is currently under
development.
In 2013, the Service funded the installation of deer exclusion
fencing at American Camp in an effort to reduce deer herbivory on
larval host plants (and the incidental consumption of eggs and larvae;
see discussion in Factor E) and to increase suitable oviposition sites.
Deer fencing was included in each year's annual work plan since 2013
and continues to be employed as an exclusion technique. Approximately
23 acres have been fenced since deer exclusion efforts began in 2013
(Shrum 2015a, in litt.).
The various forms of deer exclusion fencing that have been used
have resulted in mixed success in preventing deer from consuming larval
host plants. For example, in 2015, electrified fencing alone proved
ineffective at excluding deer at three of five research sites at
American Camp (Lambert 2015d, p. 17). However, electric and wire-mesh
fencing combined have reduced deer herbivory on larval host plants when
compared to years when exclusion fencing was not employed (Lambert
2015d, p. 17). In one large expanse of habitat at American Camp, the
distribution of field mustard was essentially limited to the fenced
areas in 2015, although environmental conditions shifted substantively
in 2016, allowing for a large flush of persistent field mustard beyond
the fenced areas (Lambert 2014a, p. 23; Lambert 2015a, p. 5; Lambert
2015d, p. 17; Lambert 2016, p. 35). Despite these challenges, deer
exclusion fencing remains an important tool for protecting island
marble butterfly habitat, especially early in the flight season when we
expect survivorship to be the highest (Lambert 2015d, p. 19). For
example, in 2016 (after the publication of our 12-month finding on
April 5, 2016 (81 FR 19527)), deer were completely excluded from
research sites at American Camp for the first time, resulting in a
quarter acre of restored habitat for host plants, and increased
survival in island marble butterflies on field mustard than in previous
years (Lambert 2016, p. 11).
The annual work plans have also included efforts to control weedy
native and nonnative species and encroaching woody plants.
Specifically, NPS has removed hundreds of Douglas-fir trees and dozens
of acres of Rubus armeniacus, R. laciniatus (blackberry),
Symphoricarpos albus (snowberry), and Crataegus monogyna (one-seeded
hawthorn) from the American Camp prairie. These actions have slowed the
invasion of native and nonnative species and encroachment by woody
plants and created early-successional conditions that likely provided
some

[[Page 15911]]

nectaring habitat for the island marble butterfly. However, few larval
host plants germinated from the seed bank in the areas cleared of
encroaching plants. Another area of focus under the work plan for
controlling invasive species is herbicide treatment of Canada thistle
in the dunes.
NPS, in collaboration with the Service and other partners, has
supported experimental research into the active establishment of island
marble butterfly habitat since 2003. In 2014, an experimental approach
for establishing oviposition and larval habitat was proposed. The
Service, in coordination with NPS, WDFW, and two local island
conservation organizations (San Juan Preservation Trust (SJPT) and San
Juan County Land Bank (SJCLB)), developed a plan to determine whether
habitat patches for the island marble butterfly could be developed in a
way that could be scaled up efficiently in a landscape context (Lambert
2014b, entire). Thirty habitat patches were created on park property at
American Camp between 2014 and 2016, and 10 more will be created in
2017 (Lambert 2016a, p. 59). Early results from this work indicate that
habitat can be created quickly and that island marble butterflies
readily use these patches for egg laying and larval development if
larval host plants germinate in time to provide oviposition sites for
early-flying butterflies (Lambert 2015d, pp. 9-12).
Each year since 2013, NPS has collected and reared a small number
of eggs and larvae in a captive-rearing program (see discussion under
Factor C, below, for more information). In 2015, the captive
individuals emerged from diapause much later than the wild population.
Despite the use of the experimental plots for oviposition by these
late-flying, captive-reared females, none of the eggs and larvae
tracked in the experimental plots survived. The high mortality was
attributed to increased predation pressure by late-season spiders and
wasps (Lambert 2015d, p. 14) (see ``Direct Predation'' under Factor C,
below). Results of captive-rearing were better in 2016, when captive-
reared island marble butterflies emerged in synchrony with the wild
population. Survivorship from egg to fifth instar larvae was also
higher in the experimental plots in 2016; three percent of the tracked
larvae survived to the fifth instar, which is a relatively high
survival rate for the island marble butterfly.
The Service, in coordination with NPS, supports habitat
conservation efforts by funding local conservation groups to establish
habitat patches on three conserved sites across the former range of the
island marble butterfly. Two of these experimental habitat patches were
established outside of American Camp in 2015 and one in 2016. Each
experimental patch has been fully fenced to exclude herbivores
(primarily deer) and allow the larval host plants to grow without
herbivory pressure (also see Factor C, ``Incidental Predation,''
below).
Education and Outreach
In 2009, the Service provided funding to WDFW for the creation of a
species fact sheet and informational handout for the public about the
biology and conservation needs of the island marble butterfly. This
pamphlet provided outreach to interested parties and increased the
awareness of the public about the decline of the island marble
butterfly. The pamphlet provided basic information about how to protect
and support habitat essential to the island marble butterfly. In 2011,
the Service collaborated with NPS, WDFW, researchers from the
University of Washington, and the Center for Natural Lands Management
to reach out to the community in a local Island Prairie Educational
Symposium to present information on current approaches to prairie
management. Information gained through years of prairie conservation
efforts in other north and south Puget Sound prairie landscapes was
shared with the local island community. Information about the island
marble butterfly and the educational materials developed were well
distributed within the community; however, this effort did not lead to
the protection or restoration of habitat adequate to ameliorate the
threat of habitat loss for island marble butterfly. Despite
considerable advances in habitat restoration, new habitat
establishment, captive-rearing, herbivore exclusion, and outreach and
education, the number of individual island marble butterflies remains
small in the single remaining population.
Summary of Habitat or Range Destruction, Modification, or Curtailment
Habitat supporting the remaining population at American Camp is
protected from development and agriculture, but is exposed to the
threats of plant succession and invasive plant species; herbivory by
deer, rabbits, and brown garden snails; and storm surges. Habitat loss
is likely a major factor impeding the recolonization of areas outside
of American Camp. Outside of American Camp, removal of larval host
plants by mowing; roadside maintenance; road, residential, or urban
development; certain agricultural practices (such as tilling, cropping,
and grazing); and landscaping activities has substantially reduced the
amount of habitat available for recolonization by the island marble
butterfly, either temporarily (e.g., mowing, tilling, cropping, or
grazing) or permanently (e.g., road, residential, and urban
development), since the island marble butterfly was rediscovered
(Miskelly and Fleckenstein 2007, p. 6; Miskelly and Potter 2009, p. 9;
Hanson et al. 2009, p. 18; Vernon 2015b in litt., p. 5). This habitat
removal is a primary factor in the loss of all the remaining
populations of this species outside of American Camp since 2006.
Since 2011, NPS has made substantial and sustained efforts to
expand island marble butterfly habitat and to improve the composition
and structure of the plant community to become more suitable for the
island marble butterfly. Due to challenges in establishing suitable
habitat and protecting it from the threats described above, only a few
acres of high-quality habitat for island marble butterfly have been
restored on the American Camp landscape. Many more acres within
American Camp have been improved by restoration actions or protected
from deer herbivory, but are not yet considered high quality or fully
secure from herbivory by deer. To date, these efforts may have resulted
in a small positive response in the island marble butterfly population,
as evidenced by the 3 percent increase in survivorship from the fourth
to fifth instar in 2016. However, the number of those individuals that
will successfully pupate and emerge as winged adults in the spring
remains to be seen. Conservation efforts by NPS have also resulted in
significant contributions to our understanding of island marble
butterfly habitat and threats to that habitat. Outside of American
Camp, the only conservation efforts that specifically create habitat
for the species are the small island marble butterfly habitat plots
established by SJPT and SJCLB. These efforts will be crucial to
establishing new populations of island marble butterfly in the future,
but the achievement is too recent for their effectiveness to be
evaluated, especially in the context of the extensive, ongoing habitat
loss from changing land use, changing agricultural practices, and other
factors that inhibit recolonization by island marble butterflies
outside of American Camp.
Despite successful habitat restoration experiments, continued use
of deer exclusion fencing, and the removal of woody plants and
nonnative and native weedy species, the increase in the total area of
currently suitable habitat within

[[Page 15912]]

American Camp has not been fully quantified, though it remains small
(on the scale of quarters of acres). Despite these minor gains in
habitat as a result of restoration since we published our 12-month
finding on April 5, 2016 (81 FR 19527), the range of the species--the
number of sites within American Camp where it is observed--has
continued to contract, and the number of island marble butterflies
observed each year remains low. Conservation measures will need to
continue into the future, with monitoring to assess their long-term
value to the island marble butterfly. Until measureable changes to the
island marble butterfly population have been documented, it will be
difficult to determine whether the implemented measures are effecting
positive change in the status of the island marble butterfly. Based on
the analysis above, we conclude that plant succession and competition
with invasive species, herbivory by deer and brown garden snails, and
storm surges are likely to have population-level impacts on the island
marble butterfly.

Factor B. Overutilization for Commercial, Recreational, Scientific, or
Educational Purposes

Overutilization for Commercial or Recreational Purposes
Under NPS regulations, collection of living or dead wildlife, fish,
or plants, or products thereof, is prohibited on lands under the
jurisdiction of NPS without a permit (36 CFR 2.1(a)(1)(i) and
(a)(1)(ii)), but there are no State or County regulations that prohibit
recreational collection of the island marble butterfly at this time.
Rare butterflies and moths are highly prized by collectors, and an
international trade exists in specimens for both live and decorative
markets, as well as the specialist trade that supplies researchers
(Collins and Morris 1985, pp. 155-179; Morris et al. 1991, pp. 332-334;
Rieunier and Associates 2013, entire). Before the island marble
butterfly was formally described, collectors may have exerted little
pressure on the taxon because it was unknown and because it occurs in
remote islands that had been little-surveyed for butterflies. Following
formal description of the species in 2001, at least three inquiries
about potential for collection were made to WDFW, which is responsible
for managing fish and wildlife in the State of Washington, and one with
NPS at American Camp, which requires a permit for the collection of any
plant or animal from park property (Reagan 2015, in litt.). WDFW has
discouraged collection, and NPS rejected the single permit request for
collection it received (Reagan 2015, in litt.; Weaver 2015a, in litt.).
In addition to these permit requests, we are aware of one specimen of
the island marble butterfly purportedly being listed for sale on a
website devoted to trade in butterfly species (Nagano 2015, pers.
obs.), although the origin and authenticity of this specimen could not
be verified.
Even limited collection of butterfly species with small populations
could have deleterious effects on the reproductive success and genetic
variability within those populations and could thus contribute
eventually to extinction or local extirpation (Singer and Wedlake 1981,
entire; Gall 1984, entire). Capture and removal of females dispersing
from a population also can reduce the probability that new populations
will be established or that metapopulation structure will be developed
or maintained. (A metapopulation is a group of spatially separated
populations that interact when individual members move from one
population to another.) Collectors pose a potential threat because they
may not be aware of other collection activities, and are unlikely to
know, and may not care, whether or not they are depleting numbers below
the threshold necessary for long-term persistence of populations and
the species (Martinez 1999, in litt.). This is especially true if
collectors lack adequate biological training or if they visit a
collection area for only a short period of time (Collins and Morris
1985, p. 165). In addition, collectors often target adult individuals
in perfect condition, including females that have not yet mated or had
the opportunity to lay all of their eggs. Some collectors go to the
length of collecting butterfly eggs in order to rear perfect specimens
(USDOJ 1995, p. 2).
Collection of the island marble butterfly, which is prohibited on
NPS lands, could potentially occur without detection because occupied
areas are not continuously patrolled and adult butterflies do move
outside of protected areas onto adjoining lands where collection is not
currently prohibited. Consequently, the potential for collection of
adult island marble butterflies, and especially surreptitious
collection of early stages (eggs, larvae, and pupae), exists, and such
collection could go undetected, despite the protection provided on NPS
lands. Taking into consideration the small remaining population,
illegal collection could have strong detrimental effects on the known
population, were it to occur. However, no illegal collection efforts
for this species have been documented to date.
Scientific Overutilization
The widespread surveys that took place in the period 2005-2012
included capturing and releasing butterflies when necessary for
positive identification, as specified in Miskelly and Fleckenstein 2007
(p. 4). Although a limited number of individuals may have been injured
or killed during handling, no data exist on the number of individuals
captured, injured, or killed. To our knowledge, there have been three
documented instances of island marble butterfly collection or handling
for scientific purposes since the rediscovery of the species. In 2005,
two male specimens were collected by WDFW surveyors as vouchers to
document newly discovered island marble sites (Miskelly and Potter
2005, pp. 4, 5; Potter 2016, in litt.). In 2008, a mark-release-
recapture (MRR) study of the species' demography involved the capture
and marking of 97 individual adult island marble butterflies and
recapture of 56 butterflies across four separate sites, and some
individuals were recaptured more than once (Peterson 2009, entire;
Peterson 2010, entire). A single individual butterfly was collected as
a voucher specimen under a WDFW scientific collection permit in 2008
for the MRR study (Potter 2016, in litt.). The other scientific use of
the island marble butterfly of which the Service is aware took place in
2013, when two adult butterflies were collected by WDFW for a genetic
assessment of the island marble butterfly, the results of which were
inconclusive (Potter 2015b, in litt.).
The handling of adult butterflies for scientific purposes has been
evaluated for effects on populations elsewhere in western North America
(Singer and Wedlake 1981; Gall 1984). Murphy (1988, p. 236) reported
that MRR work by others resulted in about 10 percent mortality to the
endangered mission blue butterfly (Icaricia icarioides missionensis);
however, studies by Singer and Wedlake (1981, entire) with other
butterflies resulted in less than 2 percent of the marked butterflies
being recaptured, suggesting that mortality from handling the
butterflies may have been a factor.
Peterson's 2008 MRR study may have resulted in unintended injury or
mortality to island marble butterfly individuals, but we have no
evidence to suggest that the study resulted in population- or species-
level effects. Surveyors were unable to recapture 38 percent of the
handled individuals during the short duration of this

[[Page 15913]]

research, but whether this research directly increased mortality for
the handled individuals is unknown. Several outcomes could have led to
this low recapture rate: The butterflies may have fully matured after
completing their life cycle and died during this period; they may have
been injured during handling and died following release; they may have
become more susceptible to other stressors after handling (e.g.,
predation); or they may have simply eluded recapture. Based on the
relative encounter rate for the island marble butterfly that was
measured during subsequent years (see ``Abundance,'' above, for
additional information), this research does not appear to have
contributed to a constriction in the range of the species or a decline
in the abundance of individuals.
The probability of numerous future collections of live island
marble butterflies for research purposes is low because all researchers
who study the island marble butterfly work collaboratively with the
Service, NPS, and WDFW and are aware of the very low and declining
number of individual butterflies. Any research proposal requiring the
collection and removal of live island marble butterflies from the
population is carefully reviewed to determine whether the conservation
benefit to the species outweighs the loss of individuals.
Summary of Overutilization for Commercial, Recreational, Scientific, or
Educational Purposes
We continue to find that overutilization does not have a
population-level impact on the island marble butterfly for the
following reasons: The lack of evidence of commercial or recreational
collection of island marble butterflies; our conclusion that handling
of the species during the 2008 MRR study did not result in documented
negative effects to island marble butterfly populations; and the small
number of individuals collected for genetic evaluation.

Factor C. Disease or Predation

Disease
There is a single report of disease affecting the island marble
butterfly (Miskelly 2004, p. 35). We discussed this observation with
the author and discovered that this was an isolated event and that the
mortality was likely attributable to causes other than disease
(Miskelly 2015a, in litt.). Therefore, there is no evidence to suggest
that disease is currently a threat to the island marble butterfly.
Direct Predation
Predation is a risk for island marble butterflies during all stages
of their life cycle, although mortality is highest during the earliest
stages of life: Egg to first instar (Lambert 2011, p. 92). A study
conducted from 2005 through 2008 on survivorship of the island marble
butterfly identified high levels of mortality attributable to predation
by spiders and, to a lesser extent, paper wasps (Polistes sp.) (Lambert
2011, p. 117). Two species of spider, Pardosa distincta and Zelotes
puritanus, both native to Washington State, prey on adult island marble
butterflies and may also account for a large proportion of the
predation on eggs and larvae (Lambert 2011, p. 100; Crawford 2016, in
litt.). The paper wasp common to American Camp is the nonnative
Polistes dominula (Miskelly 2015b, in litt.), discovered in the State
of Washington in 1998 (Landolt and Antonelli 1999, entire).
Direct predation of eggs and larvae was the greatest source of
mortality in this 4-year study, affecting 47 percent of all individuals
tracked (Lambert 2011, p. 99). Mortality levels attributable to direct
predation varied depending on the larval host plant used, with almost
80 percent mortality attributable to direct predation on Menzies'
pepperweed and approximately 40 percent on field mustard (Lambert 2011,
p. 117). These differences are likely attributable to variation in the
structure and growth form of the larval host plants that can facilitate
access by predators (Lambert 2011, p. 100).
In addition, predation on island marble butterfly larvae by spiders
and wasps increases as the season advances (Lambert 2015d, p. 14). This
increase is likely because: (a) As spiders mature, they are more
effective at locating and consuming the larvae; and (b) wasps increase
in number as the season progresses (Reeve 1991, pp. 104-106), and the
predation pressure they exert on their prey species increases with
these increased numbers. Later emergence of island marble butterflies
has been observed to correlate closely with increased predation
pressure on island marble larvae; in the 2015 field season, when
emergence was notably late, none of the 329 individuals tracked from
egg through their larval development survived to form a chrysalis
(Lambert 2015d, p. 14) (see Cumulative Effects, below, for additional
discussion). Predation on adult island marble butterflies by birds and
spiders has been observed anecdotally, although no effort has been made
to quantify mortality attributable to predation on adults (Lambert
2011, p. 90; Vernon and Weaver 2012, p. 10). We found no evidence to
suggest that predation by small mammals or other vertebrate predators
presents a threat.
Direct predation of island marble butterfly eggs and larvae is
ongoing where the species occurs (at American Camp) and is expected to
continue into the future. Direct predation of eggs and larvae is a
significant cause of mortality for the island marble butterfly,
consistently accounting for more than 45 percent of deaths for tracked
individuals (Lambert 2011, p. 99; Lambert 2015d, p. 14). Native spiders
are responsible for a significant proportion of observed predation, and
the island marble butterfly presumably coexisted for hundreds or
thousands of years with these spiders. However, the small and declining
numbers of island marble butterflies, under pressure from habitat loss
and other threats, cannot now tolerate what may once have been a
sustainable rate of natural predation. The threat of direct predation
affects the island marble butterfly at the individual, population, and
species levels (see Factor E discussion, below, for more information).
Incidental Predation
Incidental predation by browsing black-tailed deer also is a common
source of mortality for island marble butterfly eggs and larvae
(Lambert 2011, pp. 93-97; Lambert 2015d, pp. 17-18). As discussed under
Factor A, female island marble butterflies select oviposition sites on
or near the tips of the inflorescences of the larval host plants, which
is the same portion of the plant that deer prefer to browse (Lambert
2015c, in litt.). Similar to rates of direct predation, each species of
larval host plant is correlated with differing levels of mortality
attributable to deer browse. Incidental predation by deer was highest
on field mustard, which accounted for slightly more than 40 percent of
mortality tracked for this larval host plant over the course of the 4-
year study (Lambert 2011, p. 117). Mortality attributable to deer
browse was less than 10 percent for both Menzies' pepperweed and tumble
mustard (Lambert 2011, p. 117).
In nearly every report provided to the Service, deer browse has
been identified as particularly problematic for the island marble
butterfly at American Camp as well as throughout the species' former
range, where browsing deer continue to degrade the butterfly's habitat
(Miskelly and Fleckenstein 2007, p. 6; Miskelly and Potter 2009, pp.
11, 15; Hanson et al. 2009, pp. 4, 13, 20; Hanson et al. 2010, pp. 21-
22; Potter et

[[Page 15914]]

al. 2011, pp. 5, 13; Lambert 2011, p. 104; Lambert 2014a, entire;
Vernon and Weaver 2012, p. 9; Weaver and Vernon 2014, p. 10; Lambert
2014a, p. 3; Lambert 2015d, pp. 17-18; Vernon 2015a, p. 12). Incidental
predation by deer is a significant cause of mortality of the island
marble butterfly at American Camp (Lambert 2014a, p. 3). Incidental
predation by deer is a threat of increasing severity within American
Camp, where it affects the island marble butterfly at the individual,
population, and species level; outside American Camp, this source of
habitat degradation is ongoing throughout the formerly occupied range
of the species because of the apparent increase in deer numbers
throughout the San Juan Islands (Milner 2015, in litt.; McCutchen 2016,
in litt.).
Although incidental predation by other herbivores has not been as
rigorously quantified as it has been for black-tailed deer, the
negative effects of livestock on occupied larval host plants cannot be
discounted (Miskelly and Fleckenstein 2007, p. 5; Miskelly and Potter
2009, pp. 9, 11, 15; Hanson et al. 2009, pp. 18, 20; Hanson et al.
2010, pp. 5, 16, 21; Potter et al. 2011, p. 13; Vernon 2015c in litt.,
entire). Incidental predation by livestock, brown garden snails, and
European rabbits is possible where the range of the island marble
butterfly overlaps with these species. However, in the case of European
rabbits, only two documented instances exist of rabbits consuming
plants with eggs or larva on them (Lambert 2015d, p. 17). Suitable
island marble butterfly larval habitat is closely monitored at American
Camp, so while consumption of occupied larval host plants by European
rabbits does occasionally take place, it is currently rare,
geographically circumscribed, and does not have a population-level
impact to the species. The existing information does not indicate that
incidental predation by livestock, brown garden snails, and European
rabbits is occurring at a rate that currently causes population-level
impacts to the island marble butterfly.
Conservation Efforts To Reduce Disease or Predation
As described above under ``Habitat Conservation and Restoration,''
the Service and NPS installed deer exclusion fencing in American Camp
from 2013 to 2016 to reduce browsing by black-tailed deer on the larval
host plants field mustard and tumble mustard. The fencing was placed to
reduce incidental predation, as well, by protecting areas where larval
host plants are most likely to be occupied by island marble butterfly
eggs and larvae.
The Service has supported ongoing research into the effects of deer
exclusion fencing on island marble butterfly survival. The first deer
exclusion fencing was erected in three locations of American Camp in
2013. Areas immediately adjacent to the fenced habitat with similar
structure, quality, and connectivity as the fenced habitat were left
unfenced as control plots. First-year monitoring of deer exclusion
areas showed that 74 percent of eggs tracked survived to first instar
in the fenced area compared with 41 percent survival to first instar in
the control plots (Lambert 2014a, p. 6). In 2014, additional deer
exclusion fencing was installed and different types of exclusion
fencing were compared. Wire-mesh fencing was found to be effective at
preventing incidental predation by deer, while electric fencing was
determined to be largely ineffective at excluding deer, although
mortality from deer in electric-fenced areas was lower than in previous
years (Lambert 2015d, pp. 17-18). Deer exclusion fencing has emerged as
an important tool for protecting eggs and early instar larvae from
consumption by deer, especially early in the flight season when
survivorship is expected to be the highest (Lambert 2015d, p. 19;
Lambert 2016, pp. 3, 27).
Summary of Disease and Predation
The best available information does not indicate that disease is a
threat to the island marble butterfly. However, a substantial amount of
research completed since 2006 clearly documents the effects of
predation. Direct and incidental predation rates, together, account for
the vast majority of the recorded deaths of island marble butterfly
eggs and larvae at American Camp. Although deer exclusion fencing at
American Camp has been an important tool for reducing mortality due to
incidental consumption since 2013, the number of island marble
butterflies observed continues to be low. No conservation measures have
yet been identified to address the threat of predation from paper wasps
and spiders. Taken together, all forms of predation have pervasive,
population-level impacts on the island marble butterfly.

Factor D. The Inadequacy of Existing Regulatory Mechanisms

Under this factor, we examine whether existing regulatory
mechanisms ameliorate or exacerbate the threats to the species
discussed under the other factors. Section 4(b)(1)(A) of the Act
requires the Service to take into account ``those efforts, if any,
being made by any State or foreign nation, or any political subdivision
of a State or foreign nation, to protect such species. . . .'' In
relation to Factor D under the Act, we interpret this language to
require the Service to consider relevant Federal, State, and tribal
laws, regulations, and other such mechanisms that may ameliorate or
exacerbate any of the threats we describe in threat analyses under the
other four factors, or otherwise enhance conservation of the species.
We give strongest weight to statutes and their implementing regulations
and to management direction that stems from those laws and regulations.
An example would be State governmental actions enforced under a State
statute or constitution, or Federal action under statute.
Federal Laws and Regulations
American Camp, as part of San Juan Island National Historical Park,
is managed under the National Park Service's Organic Act and
implementing regulations. The National Park Service Organic Act of
1916, as amended (54 U.S.C. 100101 et seq.), states that the National
Park Service ``shall promote and regulate the use of the National Park
System . . . to conserve the scenery, natural and historic objects, and
wild life in the System units and to provide for the enjoyment of the
scenery, natural and historic objects, and wild life in such manner and
by such means as will leave them unimpaired for the enjoyment of future
generations'' (54 U.S.C. 100101(a)). Further, 36 CFR 2.1(a)(1)(i) and
(a)(1)(ii) specifically prohibits collection of living or dead
wildlife, fish, or plants, or parts or products thereof, on lands under
NPS jurisdiction. This prohibition on collection extends to the island
marble butterfly where it exists on NPS-managed lands. In addition,
under the general management plan for San Juan Island National
Historical Park, NPS is required to follow the elements of the
conservation agreement (NPS 2008, p. 73). This includes restoring
native grassland ecosystem components at American Camp, avoiding
management actions that would destroy host plants, avoiding vegetation
treatments in island marble butterfly habitat when early life-stages
are likely to be present, and implementing a monitoring plan for the
species (Pyle 2006, pp. 10-12).
The Bureau of Land Management (BLM) owns the 27-ac (11-ha) Cattle
Point Lighthouse property east of American Camp and Cattle Point
Natural Resource Conservation Area. This site was formerly occupied by
island marble butterflies, is proximal to occupied habitat on American
Camp,

[[Page 15915]]

and contains suitable habitat for the species. The Cattle Point
Lighthouse property is part of the San Juan Islands National Monument
established by Presidential proclamation on March 25, 2013, under the
American Antiquities Act of 1906 (54 U.S.C. 320301 et seq.). Under this
proclamation, the monument is being managed as part of the National
Landscape Conservation System, requiring that the land be managed ``in
a manner that protects the values for which the components of the
system were designated'' (16 U.S.C. 7202(c)(2)). The first resource
management plan for the National Monument is still in development, so
specific regulatory protections for the species and its habitat have
not yet been established. Nevertheless, anthropogenic threats at this
site are unlikely given its current designation as a National Monument.
The island marble butterfly is also listed as a sensitive species
for the purposes of the BLM's Sensitive Species Policy (BLM 2008, p. 3;
USFS 2015, entire). This policy directs the BLM to initiate
conservation measures that reduce or eliminate threats and minimize the
likelihood of listing under the Act, but until the resource management
plan for the National Monument is complete, the BLM has not identified
the required conservation measures. At this time, it is unclear what
protections, if any, these existing regulatory mechanisms will confer
to the island marble butterfly.
State Laws and Regulations
State laws and regulations that apply across San Juan and Lopez
Islands include provisions to limit collection of butterflies for
scientific purposes, but no specific protections to island marble
butterfly habitats. The island marble butterfly is currently classified
as a candidate species by the State of Washington (WDFW 2015a, p. 2).
Candidates are those species considered by Washington State to be
sensitive and potentially in need of protection through the process of
designation as endangered, following procedures established by the
Washington Administrative Code (WAC) (232-12-297). However, candidates
are not afforded any specific regulatory protections (Potter 2015c, in
litt.). The island marble butterfly is afforded limited State
regulatory protections from overcollection as the State of Washington
requires a scientific collection permit for handling or collecting any
fish, or wildlife, their nests, or eggs for scientific purposes (WAC
220-20-045; Revised Code of Washington (RCW) 77.32.240).
The island marble butterfly was identified as critically imperiled
in the Washington State Comprehensive Wildlife Conservation Strategy
(WDFW 2005, pp. 219, 314, 336-337). Since 2005, WDFW has retired the
Comprehensive Wildlife Conservation Strategy and incorporated it into
Washington's State Wildlife Action Plan (SWAP). Although the SWAP
addresses the island marble butterfly's conservation status, identifies
it as a ``species of greatest conservation need,'' and recommends
conservation actions (WDFW 2015b, pp. 3-39), the SWAP is not a
regulatory mechanism.
WDNR owns the Cattle Point Natural Resources Conservation Area
consisting of 112 acres directly to the east of American Camp, a
portion of which provides potentially suitable habitat for island
marble butterflies. Natural resource conservation areas are managed to
protect outstanding examples of native ecosystems; habitat for
endangered, threatened, and sensitive plants and animals; and scenic
landscapes. Removal of any plants or soil is prohibited unless written
permission is obtained from WDNR (WAC 332-52-115).
Local Laws and Regulations
American Camp is the only area known to be occupied by the island
marble butterfly, and because the area is managed by NPS under the
National Park Service's Organic Act and implementing regulations, local
laws and regulations governing land use do not apply. However, the
following local laws and regulations may provide some benefit to the
island marble butterfly, should the species expand its range or
recolonize suitable habitat areas outside American Camp.
The Washington State Growth Management Act of 1990 (GMA) requires
all jurisdictions in the State to designate and protect critical areas.
The State defines five broad categories of critical areas, including:
(1) Wetlands; (2) areas with a critical recharging effect on aquifers
used for potable water; (3) fish and wildlife habitat conservation
areas; (4) frequently flooded areas; and (5) geologically hazardous
areas. The upland prairie habitat type that island marble butterflies
may use, but are not restricted to, is considered both a fish and
wildlife habitat conservation area and an area with a critical
recharging effect on aquifers under the GMA. Identification as a fish
and wildlife habitat conservation area mandates that each county within
Washington State preserve and protect the fish and wildlife associated
with each habitat conservation area by developing policies and
regulations to protect the functions and values of critical areas.
Within counties, the mandate to protect and regulate critical areas
applies to all unincorporated areas. In addition, incorporated cities
within counties are required to address critical areas within their
``urban growth area'' (UGA; the area in which urban growth is
encouraged by the municipal government) independently. The only
incorporated city within San Juan County is Friday Harbor, which is
located outside of NPS-owned land on San Juan Island and outside of
habitat currently occupied by the island marble butterfly. The Friday
Harbor Comprehensive Plan provides no protections for animal species
that are not listed as ``threatened or endangered.''
San Juan County encompasses the range of the island marble
butterfly. The County regulates critical areas through a Critical Areas
Ordinance, which mandates protection for species listed under the Act
through San Juan County Critical Areas Ordinance (section 18.30.160,
Fish and Wildlife Habitat Conservation Areas). The Critical Areas
Ordinance also identifies species of local importance, including the
island marble butterfly (San Juan County 2015, p. 26), and provides
protection for the island marble butterfly by requiring that
development applications for areas determined to be occupied by the
island marble butterfly develop a habitat management plan consistent
with County recommendations for the conservation of the island marble
butterfly prior to permitting. The San Juan County Comprehensive Plan
recommends that property owners with occupied island marble butterfly
habitat avoid the use of insecticides and herbicides, limit grazing and
agricultural disturbance, and protect areas with larval host plants
during the development process (San Juan County 2015, pp. 40, 45).
However, the conservation recommendations are not comprehensive enough
to prevent local extirpation of the island marble butterfly because
they do not address all of the stressors influencing its persistence
(e.g., landscaping, permanent landscape conversion, mowing, etc.), as
evidenced by the complete loss of occupied island marble butterfly
habitat within areas developed since 2006 (see ``Development,'' above,
under Factor A).
In addition, the San Juan County Comprehensive Plan concentrates
urban density within UGAs in order to preserve the rural nature of the
San Juan archipelago (San Juan County 2010, entire). We considered the
plan in our

[[Page 15916]]

2006 12-month finding (71 FR 66292, November 14, 2006), concluding that
the restriction of high-density development would lead to the
maintenance of suitable habitat on Lopez and San Juan Islands. While
preserving the low-density agricultural environment on San Juan and
Lopez Islands partially prevents the direct conversion of suitable
island marble butterfly habitat to other incompatible uses (e.g.,
impermeable surfaces, manicured lawns, residential housing), new
evidence indicates that, despite these planning efforts, island marble
butterfly habitat has been severely curtailed rangewide since 2006, due
to a variety of factors (e.g., mowing, landscaping, or removal of host
plants) (Miskelly and Potter 2005, p. 6; Miskelly and Fleckenstein
2007, p. 6; Potter 2015a, in litt.).
Summary of Existing Regulatory Mechanisms
The island marble butterfly and its host plant are afforded
substantial regulatory protections from anthropogenic threats at
American Camp through NPS regulations and the current general
management plan for San Juan Island National Historical Park. In
addition, State- and County-level regulatory mechanisms that influence
development and zoning on San Juan and Lopez Islands are generally
beneficial to suitable habitat that could be occupied by the island
marble butterfly in the future. In summary, the existing Federal,
State, and local regulatory mechanisms provide some benefits to the
island marble butterfly and its habitat, but do not sufficiently
ameliorate all the threats to the species.

Factor E. Other Natural or Manmade Factors Affecting Its Continued
Existence

Under Factor E, we evaluate the island marble butterfly's small
population size and its vulnerability to stochastic events, vehicular
collisions, insecticide application, and climate change.
Small Population Size and Vulnerability to Stochastic Events
Since its rediscovery in 1998, the island marble butterfly has been
documented to have a narrow distribution, which has become increasingly
constrained as secure habitat has been reduced or destroyed throughout
its range (Miskelly and Potter 2005, entire; Miskelly and Fleckenstein
2007, entire; Miskelly and Potter 2009, entire; Hanson et al. 2009,
entire; Hanson et al. 2010, entire; Potter et al. 2011, entire; Vernon
and Weaver 2012, entire; Weaver and Vernon 2014, entire; Potter 2015a,
in litt.; Vernon 2015a, entire). Declining numbers for the island
marble butterfly have been documented during annual monitoring at
American Camp that has taken place from 2004 through 2015 (see
``Abundance,'' above), and the species now appears to be restricted to
a single known population centered on American Camp.
Compared to large populations, small populations are
disproportionately affected by environmental, demographic, and genetic
stochasticity, and thus face greater risk of extinction (Frankham 1996,
p. 1506; Saccheri et al. 1998, entire; Harper et al. 2003, pp. 3349,
3354). Environmental stochasticity is the variation in birth and death
rates from one season to the next in response to weather, disease,
competition, predation, or other factors external to the population
(Shaffer 1981, p. 131). For example, drought or predation, in
combination with a low population year, could result in extirpation,
and butterflies are known to be sensitive to environmental variation,
increasing the influence of this factor (Weiss et al. 1993, pp. 267-
269). Stochastic environmental events can be natural or human-caused.
Demographic stochasticity refers to random variability in survival
or reproduction among individuals within a population (Shaffer 1981, p.
131). This random variability has a proportionately large effect on
small populations, such that any loss of beneficial alleles (genes that
provide for more successful reproduction and survival) may result in a
rapid reduction in fitness, making small populations much more likely
to go extinct than large populations (Frankham 1996, p. 1507). Genetic
stochasticity, or genetic drift, describes random changes in the
genetic composition of a population that are not related to systemic
forces such as natural selection, inbreeding, or migration. In small
populations, genetic stochasticity is more likely to result in reduced
fitness and ultimately a lower number of individuals contributed to
each successive generation. Small, narrowly distributed populations
generally have lower genetic diversity than larger populations, which
can result in less resilience to changing environmental conditions.
Because the island marble butterfly persists in low numbers, loss
of a portion of the remaining population could have disproportionately
negative effects. Storm surges that destroy nearshore habitat
containing overwintering island marble butterfly chrysalids may further
deplete the genetic diversity of the island marble butterfly.
Similarly, in grassland habitat, a poorly timed or uncontrolled fire
could destroy a large portion of the remaining population. The effect
of predation, which has always been at least a baseline limiting factor
for the island marble butterfly, is magnified when there are so few
individuals left. Additional stochastic events that could potentially
be devastating include a late-spring weather abnormality, such as an
extended hard freeze or a powerful storm during the flight season; a
year in which predator populations were unusually high; or introduction
of a novel predator. Given that the very small population at American
Camp is likely the only remaining population of the species, we
conclude that small population size makes it particularly vulnerable to
a variety of likely stochastic events, and this constitutes a threat to
the island marble butterfly at the individual, population, and species
levels.
Vehicular Collisions
Habitat occupied by the island marble butterfly within American
Camp is bisected by Cattle Point Road, a highway that is the only point
of access for a small residential community at the southeastern tip of
San Juan Island (approximately 100-150 housing units) and, as such, is
routinely driven by the residents. The highway runs along the shoulder
of Mount Finlayson, a landscape feature that male island marble
butterflies typically follow when patrolling for females (Lambert
2016b, pers. comm.). While there have been no specific reports of
island marble butterfly road kills, the presence of the highway within
occupied habitat exposes the species to potential vehicle collisions.
Few studies provide detail on the scale of vehicle-caused mortality for
invertebrate species, and even fewer specifically examine butterfly
mortality or the effects of traffic on individual butterfly species
(Seibert and Conover 1991, p. 163; Munguira and Thomas 1992, entire;
Rao and Girish 2007, entire).
One peer-reviewed study that examined vehicular mortality for
butterflies found that a species in the same family as the island
marble butterfly, Pieris rapae, was more likely to be struck and killed
by vehicles in comparison to the other more sedentary species in the
study, with 7 percent of a local population killed by cars in a 44-day
period (Munguira and Thomas 1992, p. 325). The study was conducted
along ``main roads'' in the United Kingdom that connected relatively
large

[[Page 15917]]

cities (Munguira and Thomas 1992, p. 317); thus, it is likely they had
more traffic than the highway at American Camp. While the authors of
the study did not find the percentage of the population killed by
vehicles to be significant in comparison to mortality caused by other
natural factors affecting their survival (Munguira and Thomas 1992, p.
316), the loss of individual island marble butterflies could have
disproportionately large negative effects on the species as a whole
because of its restricted range and small population size.
Male island marble butterflies are attracted to white (ultraviolet-
reflecting) objects that may resemble females and have been observed to
investigate white flowers (e.g., field chickweed and yarrow), white
picket fences, and white lines painted on the surface of roads (Lambert
2011, p. 47). The highway through American Camp has fog lines that are
painted white that could be attractive to adult butterflies, thereby
increasing their risk of being killed by vehicles. The centerlines on
the highway are painted yellow.
Given the presence of a highway within the single remaining site
occupied by island marble butterflies, and their attraction to white
road stripes that are present along the Cattle Point Road edges, we
expect that some vehicular mortality is likely. However, we cannot
estimate the severity of this stressor, as vehicular mortality has not
been specifically studied for the island marble butterfly or documented
at American Camp. Therefore, while there is the potential for mortality
resulting from vehicular collisions, the best available information
does not indicate that vehicular collision currently has an individual,
population, or species-level impact to the island marble butterfly.
Insecticide Application
The best available information does not indicate any insecticide
use in proximity to areas that are currently known to be occupied by
the island marble butterfly at American Camp. However, remnant patches
of potentially suitable habitat for the species are located within a
matrix of rural agricultural lands and low-density residential
development, where insecticides may be used. One such insecticide that
has the potential to adversely affect the island marble butterfly if
applied during its larval phase is Bacillus thuringiensis var. kurstaki
(Btk). This insecticide, derived from a common soil bacterium, is used
in a wide range of settings, including organic agriculture, for the
control of lepidopteran (butterfly and moth) pest species (National
Pesticide Information Center 2015, p. 1; Oregon Health Authority 2015,
p. 1). In forestry, it is used broadly for the control of the Asian and
European gypsy moth species (Lymantria dispar, and L. dispar dispar,
respectively) (see WSDA 2015, entire). Btk is also more generally
applied for other lepidopteran pest species, such as tent caterpillars
(Malacosoma spp.).
Btk has the potential to kill the island marble butterfly larvae if
applied in close proximity and upwind of an occupied site. Spraying of
Btk has had adverse effects to nontarget butterfly and moth species
(Severns 2002, p. 169; Wagner and Miller 1995, p. 19), with butterfly
diversity, richness, and abundance (density) reduced for up to 2 years
following the application of Btk (Severns 2002, p. 168). One study
demonstrated that most nontarget lepidopteran species may be more
susceptible to Btk than target species such as Asian and European gypsy
moths or western tent caterpillars (Haas and Scriber 1998). For
nontarget lepidopterans, the early instar stages of larvae are the most
susceptible stage (Wagner and Miller 1995, p. 21).
Large-scale application of Btk in Washington State is done in a
targeted fashion in response to positive trapping of pest species. In
most years, Btk application is conducted at the scale of hundreds of
acres per year, although in years when detection of pest species are
high, such as in 2015, application of Btk may be scaled up to thousands
of acres in response (WSDA 2015, p. 1). Large-scale application of Btk
does not normally overlap with areas where the island marble butterfly
is known to occur within American Camp, although if pest species were
detected in close proximity and if the target species is active at the
same time as larvae of the island marble butterfly, the effect of Btk
treatment could be detrimental. Because the island marble butterfly
produces a single brood per year, has a spring flight season, and has
developing larvae during the summer insecticide application period,
this species is more likely to be susceptible to the adverse effects of
Btk than butterfly species with later flight and developmental periods
or those that produce multiple broods per year. Btk is commonly used to
control tent caterpillars and is likely to have been used on San Juan
Island (Potter 2015d, in litt.), although the effect on the island
marble butterfly at American Camp is not documented. At this time, the
best available information does not indicate that Btk has been applied
at or adjacent to any location where island marble butterflies are
known to occur.
We recognize that the use of insecticides could have a negative
impact on larvae of the island marble butterfly if applied in such a
way that individuals were exposed. However, there is no documented
exposure to insecticide use in the island marble butterfly at this
time. While there is the potential for high levels of mortality
resulting from insecticide exposure, we conclude that insecticide use
is not having a known impact on the island marble butterfly,
principally because of the low likelihood of exposure at American Camp.
Late Emergence of Adult Butterflies
Since regular transect surveys for the island marble butterfly
began in 2004, the first date of the flight period has shifted an
average of approximately 9 days later in the year (USFWS 2016
unpublished data). The reason for this change is unclear, and the
existing time-series is too brief to ascertain whether this change is a
trend or part of natural variability on a longer time scale. For
example, no clear correlation exists between average winter
temperatures and the beginning of the island marble flight season and
the shift toward later emergence between 2004 and 2016. Later emergence
cannot currently be attributed to climate change, although temperature
may play a role. When conditions inside the captive-rearing lab for
island marble butterflies were cooler than the ambient temperature in
2015, butterflies emerged later than the wild population (Shrum 2015b,
in litt.). The temperature was increased inside in 2016, and the
captive and wild adults emerged at the same time (Weaver 2015, in
litt.; Shrum 2016, in litt.). Other environmental conditions, including
moisture, likely influence emergence time as well (Bates et al. 2002,
p. 3).
Ongoing research has recently detected a steep increase in
mortality for late-season eggs and larvae compared to the mortality of
early-season eggs, with none of the larvae observed in study plots
surviving to the fifth instar in 2015 (Lambert 2015d, p. 14). Only a
portion of the mortality documented was attributable to starvation (25
percent); the greatest cause of mortality was attributable to direct
predation (60 percent) (Lambert 2015d, p. 14; and see discussion above
under Factor C). The single, small population of island marble
butterflies likely cannot sustain the increased late-season predation
pressure, and probable survival of fewer offspring, over multiple
years.
Climate Change
Our analyses under the Act include consideration of ongoing and
projected

[[Page 15918]]

changes in climate. The majority of climate models for the Pacific
Northwest region predict wetter winters, with an increase in the
proportion of precipitation falling as rain rather than snow due to
increasing ambient temperature, and drier summers as a result of
reduced snowpack and ensuing hydrologic drought (Mote and
Salath[eacute] 2010, p. 48). No downscaled climate models specific to
the San Juan Island archipelago are available, and San Juan Island is
not reliant on snowpack for its water. The portion of San Juan Island
where the known population of the island marble butterfly occurs is in
the rain shadow of mountain ranges on Vancouver Island, Canada, and in
Washington State, resulting in weather patterns commonly drier than
much of the rest of the Pacific Northwest (Mass 2009, entire). While
the San Juan Island archipelago may be subject to the increasing
average annual temperatures associated with climate change, it is
unclear how changing temperatures will affect the island marble
butterfly.
One predicted stressor associated with climate change for
herbivorous (plant-eating) insect species is the potential for the
development of phenological asynchrony (a mismatch in timing) between
insects and their larval host plants (Bale et al. 2002, p. 8). If an
herbivorous insect emerges earlier or later than the optimal stage of
its larval host plant, the insect may not be able to find plants at the
right stage for egg laying, or the insect's larvae may not have
adequate food resources. If the insect emerges earlier than its larval
host plant, the plants may not be detectable, leaving the animal with
no place to lay her eggs, or the plants may be too small to provide
enough forage for larvae, leading to starvation. Conversely, if the
insect emerges when the plant is at a later phenological stage, eggs
may be laid on a larval host plant that has matured to the point that
plant tissues are too tough for the larvae to consume, or the plant may
die before the insect has acquired enough resources to survive to the
pupation stage. The island marble butterfly is an early-flying species,
generally emerging in April and immediately mating and laying eggs on
the larval host plants that are available. This strategy ensures that
the host plants are young enough to provide tender plant tissue for
first instar larvae, which have mouthparts incapable of consuming
anything but the high-moisture flower buds. In the absence of access to
tender buds, early instar larvae die from desiccation (Lambert 2011, p.
12). Although evidence exists that some larvae of late-emerging island
marble butterflies have suffered starvation (Lambert 2015d, p. 14),
perhaps as a result of mismatch between butterfly and food-plant
phenology, no recurring pattern in such mismatch exists now that can be
associated with climate change. However, monitoring of phenology and
survival in the island marble butterfly is ongoing and may shed light
on this relationship in the future.
Sea-level rise associated with climate change is expected to
continue as polar ice melts, leading to an increase in ocean volume
(Adelsman et al. 2012, p. 82). The warming climate is also expected to
lead to rising ocean temperatures resulting in thermal expansion of the
water, which will also increase the volume of the ocean (Dalton et al.
2013, p. 70). Both of these effects of climate change are expected to
lead to rising sea level, which will have the direct effect of
increasing the impacts of storm surges and flooding events in low-lying
areas, such as the nearshore lagoon habitat of the island marble
butterfly (MacLennan et al. 2013, pp. 4-5; Vose et al. 2014, p. 381;
Friends of the San Juans 2014, p. 7; Whitman and MacLennan 2015, in
litt.; NOAA 2015a, entire; NOAA 2015b, entire). Because the nearshore
habitat is barely above sea level, rise in sea level increases the risk
of inundation and direct mortality for island marble butterflies
overwintering as chrysalids in low-lying nearshore habitat. Powerful
storm surges have historically deposited large amounts of coarse
sediment and driftwood in areas occupied by Menzies' pepperweed (an
estimated 5-8 percent of habitat occupied in 2006) and where a number
of island marble butterflies were overwintering as chrysalids, leading
to low numbers of individuals detected in nearshore habitat in years
following a storm surge event (Lambert 2011, pp. 99, 145-146; Lambert
2015f, in litt.). Due to the small number of individuals remaining,
mortality and habitat loss resulting from storm surges likely has a
population-level impact on the island marble butterfly, and we expect
these impacts to increase over time as an effect of global climate
change.
While some effects of global climate change, such as sea-level rise
and storm intensity, are expected to be nearly universal, warming
associated with climate change is expected to be variable or even
patchy, depending on localized weather patterns (e.g., patterns
influenced by oceanographic phenomena such as El Ni[ntilde]o and La
Ni[ntilde]a) (Adelsman et al. 2012, p. 37). The Pacific Northwest
region of the United States abuts the eastern edge of the Pacific
Ocean, which warms and cools in sync with the Pacific Decadal
Oscillation (Mantua and Hare 2002, entire). Given the unclear direction
of climate trends in the San Juan archipelago, we cannot conclude that
the island marble butterfly is exhibiting phenological changes such as
later emergence as a result of climate change, or that the species will
do so in the future.
Climate conditions that affect phenology in a given year can have
important impacts to the species, however. Cooler temperatures are
associated with later emergence of butterflies reared in captivity
(Weaver 2015, in litt.), and late emergence leads to a spike in late-
season predation on island butterfly larvae, when spider and wasp
populations are greatest (see discussions above under Factor C, and
under ``Late Emergence of Adult Butterflies''). Compared with an
abundant species with numerous, well-distributed populations, the
island marble butterfly's small remaining population is far more
vulnerable to such fluctuations in mortality.
Conservation Efforts To Reduce Other Natural or Manmade Factors
Affecting Its Continued Existence
The Service, NPS, and other partners have been implementing
multiple conservation efforts in an attempt to ameliorate the threats
posed by small population size, vulnerability to stochastic events, and
insecticide applications. No conservation efforts currently address
collisions with vehicles or the effects of climate change. Below we
summarize the conservation measures that have been implemented by NPS,
WDFW, University of Washington researchers, and conservation partners
on San Juan Island to address the threats to the island marble
butterfly described above under Factor E.
The Service, NPS, and other partners have conducted conservation
efforts to address the effects of small population size and
vulnerability to stochastic events on the island marble butterfly since
2008. Specifically, NPS and other partners began exploring methods for
captive-rearing island marble butterflies in 2008. In 2009, 16 island
marble butterfly individuals were rescued from a construction site,
reared to emergence as adult butterflies, and released in the spring of
2010 (Vernon 2015d, p. 2). In 2010, more individuals were reared as
part of a food preference experiment (Trapp and Weaver 2010, entire),
and 32 adults were released in 2011 (Vernon 2011, p. 5). These
opportunistic events demonstrated that rescue, rearing, and

[[Page 15919]]

releasing of island marble butterflies could be successful. A handbook
based on these captive-rearing events and more recent efforts was
developed to guide captive-rearing and release efforts for the island
marble butterfly (Vernon 2015d, entire).
In 2013, continued decline in the number of island marble
butterflies observed in the wild led to the rescue, captive-rearing,
and release of the species in an effort to improve survivorship and
reverse the trend of declining numbers, and provide a safety net
against stochastic events. Forty-seven individuals successfully formed
chrysalids, and 40 adult island marble butterflies emerged in the
spring of 2014, and were released at American Camp (85 percent
survival) (Vernon 2015d, p. 3). NPS has scaled up and streamlined the
captive-rearing program. In 2014, NPS converted an outbuilding into a
rearing facility, and 89 eggs and larvae were brought in for captive-
rearing. Of those, 75 adult island marble butterflies emerged (84
percent survival) in the spring of 2015, and were released at American
Camp (Silahua 2015, in litt.). In 2015, 126 eggs and larvae were
brought in for captive-rearing, 114 of which survived to become
chrysalids (Silahua 2015, in litt.).
Although the number of adult island marble butterflies recorded
during annual surveys remains small (fewer than 30 butterflies were
observed each year during monitoring for the 2014 and 2015 flight
seasons), the captive-rearing effort has likely provided crucial
support to the population remaining in the wild and will remain
necessary in the future. However, this ongoing conservation effort to
address small population size and vulnerability to stochastic events is
not without risk and does not ameliorate other threats to the species
in the long term. For example, in 2015, individuals reared in captivity
emerged late in the flight season (on or around May 13) (Weaver 2015b,
in litt.), and available data suggest that the majority of the
offspring of these captive-reared individuals died as a result of high
late-season predation rates (Lambert 2015d, p. 14; see discussion under
Factor C, above). In 2016, the date of emergence in the captive-rearing
facility was better calibrated to ambient environmental temperatures by
adjusting the temperature in the rearing facility to match those of the
surrounding outdoor area, but there are likely to be other unforeseen
challenges to successful captive-rearing.
Conservation efforts to reduce natural or manmade factors include
efforts to reduce the application of the insecticide Btk in close
proximity to sites occupied by the island marble butterfly. The final
decision over the use of insecticide for control of invasive moths and
butterflies has been, and will continue to be, made by the Washington
State Department of Agriculture after coordination with the Service and
WDFW. All pesticide used by the State of Washington is applied in
compliance with label instructions, which are designed to reduce
overspray, drift, and other negative impacts to nontarget organisms and
areas.
Summary of Other Natural or Manmade Factors Affecting Its Continued
Existence
The small population size of the island marble butterfly makes the
species highly vulnerable to stochastic events (such as storm surges
and climate anomalies) that directly or indirectly affect survival and
reproductive success or the extent of habitat. Storm surges, which can
cause direct mortality of island marble butterflies and habitat loss,
are likely to increase with climate change. Although successful
captive-rearing and release of island marble butterflies is an
important achievement that has supplemented numbers at American Camp
since 2013, threats to the species and its habitat continue. The range
of the island marble butterfly has continued to contract at American
Camp, and the number of island marble butterflies observed annually has
continued to decline. These conservation efforts will need to be
continued into the future and be monitored to assess their long-term
conservation value to the island marble butterfly before we can
determine their efficacy.

Cumulative Effects

In our analysis of the five factors, we found that the island
marble butterfly is likely to be affected by loss and degradation of
habitat, direct and incidental predation, and vulnerabilities
associated with small population size. Multiple stressors acting in
combination have greater potential to affect the island marble
butterfly than each factor alone. For example, increased sea level
resulting from climate change may enhance the impacts of storm surges
and flooding on low-lying coastal habitat where the one native larval
host plant for the species occurs. The combined effects of
environmental and demographic stochasticity, 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 a small, isolated population. Thus, factors that, by
themselves, may not have a significant effect on the island marble
butterfly, may affect the species when considered in combination.

Determination of Species' Status

Section 4 of the Act (16 U.S.C. 1533), and its implementing
regulations at 50 CFR part 424, set forth the procedures for
determining whether a species is an endangered species or threatened
species and should be included on the Federal Lists of Endangered and
Threatened Wildlife and Plants. Under section 4(a)(1) of the Act, we
evaluate all of the following factors to determine whether listing may
be warranted: (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.
As required by the Act, we have carefully assessed the best
scientific and commercial information available regarding the past,
present, and future threats to the island marble butterfly. Since the
species was discovered in the San Juan Islands in 1998, the species'
range has contracted from five populations on two islands (San Juan and
Lopez) to a single population, at American Camp on San Juan Island,
today. The causes of these extirpations are not well understood, but
likely include habitat loss outside American Camp from a combination of
sources. Within the single remaining population at American Camp, the
number of sites where island marble butterflies are detected during
surveys declined from 25 in 2007, to 4 in 2015. Encounter rates for
adult butterflies calculated from survey data have declined each year,
from almost 2 per 100 meters in 2004, to about 0.3 per 100 meters in
2015. The slight increase in this rate in 2016, to 0.6 per 100 meters,
does not reverse the overall trend of decline. Captive rearing and
release of the island marble butterfly shows promise for bolstering the
remaining population of the species. However, the potential for this
species to recolonize areas within its historical range is uncertain
due to ongoing, pervasive habitat degradation that results from
herbivory by deer and other animals on larval host plants, from plant
succession and invasion by nonnative plants that render habitat
unsuitable for

[[Page 15920]]

larval host plants, and potentially from cultivation and other land
uses. The widespread occurrence of native (spiders) and nonnative
(wasps) predators of eggs and larvae is also an ongoing threat that may
hamper or prevent potential recolonizations. Furthermore, the source
for any recolonizations consists of a single, small population already
vulnerable to these threats and to stochastic sources of mortality,
such as severe storms and other climate anomalies.
In summary, we have identified the following threats to the island
marble butterfly: (1) Habitat loss and degradation from plant
succession and competition with invasive species that displace larval
host plants; herbivory by deer, European rabbits, and brown garden
snails; and storm surges (Factor A); (2) direct predation by spiders
and wasps and incidental predation by deer (Factor C); (3) small
population size and vulnerability to stochastic events (Factor E); and
(4) the cumulative effects of small population size and the restricted
range combined with any stressor that removes individuals from the
population or decreases the species' reproductive success (Factor E).
These threats affect the island marble butterfly throughout the
entirety of its range and are ongoing and likely to persist into the
foreseeable future. These factors pose threats to the island marble
butterfly whether considered individually or cumulatively. The existing
regulatory mechanisms (Factor D) and ongoing conservation efforts are
not currently sufficient to ameliorate the impact of these threats;
despite intense focused efforts to conserve the species, population
numbers continue to decline.
The ongoing threats of habitat loss and degradation, predation, the
effects of small population size, and stochastic events that cause
mortality or reduce reproductive success render this species in its
entirety presently in danger of extinction throughout all of its range.
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.'' The ongoing threats of habitat loss
and degradation, predation, the effects of small population size, and
stochastic events that cause mortality or reduce reproductive success
render this species in its entirety presently in danger of extinction.
We find that threatened species status is not appropriate for the
island marble butterfly because of its already contracted range and
single remaining population, because the threats are ongoing and
affecting the entirety of the species, and because these threats are
expected to continue into the future.
Therefore, on the basis of the best available scientific and
commercial information, we propose listing the island marble butterfly
as an endangered species 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 endangered or threatened throughout all or
a significant portion of its range. Because we have determined that the
island marble butterfly is endangered throughout all of its range, we
do not need to conduct an analysis of whether there is any significant
portion of its range where the species is in danger of extinction or
likely to become so in the foreseeable future. This is consistent with
the Act because when we find that a species is currently in danger of
extinction throughout all of its range (i.e., meets the definition of
an ``endangered species''), the species is experiencing high-magnitude
threats across its range or threats are so high in particular areas
that they severely affect the species across its range. Therefore, the
species is in danger of extinction throughout every portion of its
range and an analysis of whether there is any significant portion of
the range that may be in danger of extinction or likely to become so
would not result in a different outcome.

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, Tribal, 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,
preparation of a draft and final recovery plan, and revisions to the
plan as significant new information becomes available. 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 also identifies recovery criteria for review of when a
species may be ready for downlisting (i.e., reclassification from
endangered to threatened status) or delisting (i.e., removal from the
List of Endangered and Threatened Wildlife or List of Endangered and
Threatened Plants) 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. We
intend to make a recovery outline available to the public concurrent
with the final listing rule, if listing continues to be warranted. When
completed, the recovery outline, draft recovery plan, and the final
recovery plan will be available on our website (http://www.fws.gov/endangered), or from our Washington Fish and Wildlife Office (see FOR
FURTHER INFORMATION CONTACT).
Implementation of recovery actions generally requires the
participation of a broad range of partners, including other Federal
agencies, States, 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

[[Page 15921]]

requires cooperative conservation efforts on all lands.
If the island marble butterfly is 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, the State of Washington
would be eligible for Federal funds to implement management actions
that promote the protection or recovery of the island marble butterfly.
Information on our grant programs that are available to aid species
recovery can be found at: http://www.fws.gov/grants.
Although the island marble butterfly is only proposed for listing
under the Act at this time, please let us know if you are interested in
participating in recovery efforts for this species. Additionally, we
invite you to submit any new information on this species whenever it
becomes available and any information you may have for recovery
planning purposes (see FOR FURTHER INFORMATION CONTACT).
Section 7(a) of the Act requires Federal agencies to evaluate their
actions with respect to any species that is 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.
Federal agency actions within the species' habitat that may require
conference or consultation or both as described in the preceding
paragraph include management and any other landscape-altering
activities on Federal lands administered by the Bureau of Land
Management, Farm Service Agency, Federal Highway Administration,
National Park Service, U.S Army Corps of Engineers, U.S. Fish and
Wildlife Service, U.S. Department of Agriculture, and the U.S. Coast
Guard.
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, make it illegal for any person subject to the
jurisdiction of the United States to take (which includes harass, harm,
pursue, hunt, shoot, wound, kill, trap, capture, or collect; or to
attempt any of these) endangered wildlife within the United States or
on the high seas. In addition, it is unlawful to import; export;
deliver, receive, carry, transport, or ship in interstate or foreign
commerce in the course of commercial activity; or sell or offer for
sale in interstate or foreign commerce any listed species. It is also
illegal to possess, sell, deliver, carry, transport, or ship any such
wildlife that has been taken illegally. Certain exceptions apply to
employees of the Service, the National Marine Fisheries Service, other
Federal land management agencies, 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. There
are also certain statutory exemptions from the prohibitions, which are
found in sections 9 and 10 of the Act.
Our policy, as published in the Federal Register on July 1, 1994
(59 FR 34272), is 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. Based on the best available information, the
following activities could potentially result in a violation of section
9 of the Act; this list is not comprehensive:
(1) Unauthorized collecting, handling, possessing, selling,
delivering, carrying, or transporting of island marble butterflies,
including import or export across State lines and international
boundaries, except for properly documented antique specimens at least
100 years old, as defined by section 10(h)(1) of the Act;
(2) Introduction of nonnative species that compete with or prey
upon the island marble butterfly or its host and nectar plants, for
example, the introduction of competing, nonnative plants or animals to
the San Juan Islands or the State of Washington;
(3) The unauthorized release of biological control agents that
attack any life stage of the island marble butterfly, for example, Btk
release in the range of the species;
(4) Unauthorized modification of the soil profiles or the
vegetation components on sites known to be occupied by island marble
butterflies; or
(5) Intentional disturbance of butterflies or their larvae, or
mowing or burning of occupied habitats during the breeding season.
Questions regarding whether specific activities would constitute a
violation of section 9 of the Act should be directed to the Washington
Fish and Wildlife Office (see FOR FURTHER INFORMATION CONTACT).

Critical Habitat

Background

Critical habitat is defined in section 3 of the Act as:
(1) The specific areas within the geographical area occupied by the
species, at the time it is listed in accordance with the Act, on which
are found those physical or biological features
(a) Essential to the conservation of the species, and
(b) Which may require special management considerations or
protection; and
(2) Specific areas outside the geographical area occupied by the
species at the time it is listed, upon a determination that such areas
are essential for the conservation of the species.
Our regulations at 50 CFR 424.02 define the geographical area
occupied by the species as: An area that may generally be delineated
around species' occurrences, as determined by the Secretary (i.e.,
range). Such areas may include those areas used throughout all or part
of the species' life cycle, even if not used on a regular basis (e.g.,
migratory corridors, seasonal habitats, and habitats used periodically,
but not solely by vagrant individuals).
Conservation, as defined under section 3 of the Act, means to use
and the use of all methods and procedures that are necessary to bring
an endangered or threatened species to the point at which the measures
provided

[[Page 15922]]

pursuant to the Act are no longer necessary. Such methods and
procedures include, but are not limited to, all activities associated
with scientific resources management such as research, census, law
enforcement, habitat acquisition and maintenance, propagation, live
trapping, and transplantation, and, in the extraordinary case where
population pressures within a given ecosystem cannot be otherwise
relieved, may include regulated taking.
Critical habitat receives protection under section 7 of the Act
through the requirement that Federal agencies ensure, in consultation
with the Service, that any action they authorize, fund, or carry out is
not likely to result in the destruction or adverse modification of
critical habitat. The designation of critical habitat does not affect
land ownership or establish a refuge, wilderness, reserve, preserve, or
other conservation area. Such designation does not allow the government
or public to access private lands. Such designation does not require
implementation of restoration, recovery, or enhancement measures by
non-Federal landowners. Where a landowner requests Federal agency
funding or authorization for an action that may affect a listed species
or critical habitat, the consultation requirements of section 7(a)(2)
of the Act would apply, but even in the event of a destruction or
adverse modification finding, the obligation of the Federal action
agency and the landowner is not to restore or recover the species, but
to implement reasonable and prudent alternatives to avoid destruction
or adverse modification of critical habitat.
Under the first prong of the Act's definition of critical habitat,
areas within the geographical area occupied by the species at the time
it was listed are included in a critical habitat designation if they
contain physical or biological features (1) which are essential to the
conservation of the species and (2) which may require special
management considerations or protection. For these areas, critical
habitat designations identify, to the extent known using the best
scientific and commercial data available, those physical or biological
features that are essential to the conservation of the species (such as
space, food, cover, and protected habitat). In identifying those
physical or biological features within an area, we focus on the
specific features that support the life-history needs of the species,
including but not limited to, water characteristics, soil type,
geological features, prey, vegetation, symbiotic species, or other
features. A feature may be a single habitat characteristic, or a more
complex combination of habitat characteristics. Features may include
habitat characteristics that support ephemeral or dynamic habitat
conditions. Features may also be expressed in terms relating to
principles of conservation biology, such as patch size, distribution
distances, and connectivity.
Under the second prong of the Act's definition of critical habitat,
we can designate critical habitat in areas outside the geographical
area occupied by the species at the time it is listed, upon a
determination that such areas are essential for the conservation of the
species. We determine whether unoccupied areas are essential for the
conservation of the species by considering the life-history, status,
and conservation needs of the species. This is further informed by any
generalized conservation strategy, criteria, or outline that may have
been developed for the species to provide a substantive foundation for
identifying which features and specific areas are essential to the
conservation of the species and, as a result, the development of the
critical habitat designation.
Section 4 of the Act requires that we designate critical habitat on
the basis of the best scientific data available. Further, our Policy on
Information Standards Under the Endangered Species Act (published in
the Federal Register on July 1, 1994 (59 FR 34271)), the Information
Quality Act (section 515 of the Treasury and General Government
Appropriations Act for Fiscal Year 2001 (Pub. L. 106-554; H.R. 5658)),
and our associated Information Quality Guidelines, provide criteria,
establish procedures, and provide guidance to ensure that our decisions
are based on the best scientific data available. They require our
biologists, to the extent consistent with the Act and with the use of
the best scientific data available, to use primary and original sources
of information as the basis for recommendations to designate critical
habitat.
When we are determining which areas should be designated as
critical habitat, our primary source of information is generally the
information developed during the listing process for the species.
Additional information sources may include any generalized conservation
strategy, criteria, or outline that may have been developed for the
species, the recovery plan for the species, articles in peer-reviewed
journals, conservation plans developed by States and counties,
scientific status surveys and studies, biological assessments, other
unpublished materials, or experts' opinions or personal knowledge.
Habitat is dynamic, and species may move from one area to another
over time. We recognize that critical habitat designated at a
particular point in time may not include all of the habitat areas that
we may later determine are necessary for the recovery of the species.
For these reasons, a critical habitat designation does not signal that
habitat outside the designated area is unimportant or may not be needed
for recovery of the species. Areas that are important to the
conservation of the species, both inside and outside the critical
habitat designation, will continue to be subject to: (1) Conservation
actions implemented under section 7(a)(1) of the Act; (2) regulatory
protections afforded by the requirement in section 7(a)(2) of the Act
for Federal agencies to ensure their actions are not likely to
jeopardize the continued existence of any endangered or threatened
species; and (3) section 9 of the Act's prohibitions on taking any
individual of the species, including taking caused by actions that
affect habitat. Federally funded or permitted projects affecting listed
species outside their designated critical habitat areas may still
result in jeopardy findings in some cases. These protections and
conservation tools will continue to contribute to recovery of this
species. Similarly, critical habitat designations made on the basis of
the best available information at the time of designation will not
control the direction and substance of future recovery plans, habitat
conservation plans (HCPs), or other species conservation planning
efforts if new information available at the time of these planning
efforts calls for a different outcome.

Prudency Determination

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 shall 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. In determining whether a designation would not be
beneficial, the factors the

[[Page 15923]]

Service may consider include but are not limited to: Whether the
present or threatened destruction, modification, or curtailment of a
species' habitat or range is not a threat to the species, or whether
any areas meet the definition of ``critical habitat.''
As discussed above, there is currently no imminent threat of take
attributed to collection or vandalism identified under Factor B for
this species, and identification and mapping of critical habitat is not
expected to initiate any such threat. In the absence of finding that
the designation of critical habitat would increase threats to a
species, we next determine whether such designation of critical habitat
would not be beneficial to the species. In our proposed listing
determination, above, we determined that there are habitat-based
threats to the island marble butterfly identified under Factor A.
Therefore, we find that the designation of critical habitat would be
beneficial to the island marble butterfly through the provisions of
section 7 of the Act. Because we have determined that the designation
of critical habitat will not likely increase the degree of threat to
the species and would be beneficial, we find that designation of
critical habitat is prudent for the island marble butterfly.

Critical Habitat Determinability

Having determined that designation is prudent, under section
4(a)(3) of the Act we must find whether critical habitat for the island
marble butterfly is determinable. Our regulations at 50 CFR
424.12(a)(2) state that critical habitat is not determinable when one
or both of the following situations exist:
(i) Data sufficient to perform required analyses are lacking, or
(ii) The biological needs of the species are not sufficiently well
known to identify any area that meets the definition of ``critical
habitat.''
When critical habitat is not determinable, the Act allows the
Service an additional year to publish a critical habitat designation
(16 U.S.C. 1533(b)(6)(C)(ii)).
We reviewed the available information pertaining to the biological
needs of the species and habitat characteristics where these species
are located. This and other information represent the best scientific
data available and led us to conclude that the designation of critical
habitat is determinable for the island marble butterfly.

Physical or Biological Features

In accordance with section 3(5)(A)(i) of the Act and regulations at
50 CFR 424.12(b), in determining which areas within the geographical
area occupied by the species at the time of listing to designate as
critical habitat, we consider the physical or biological features that
are essential to the conservation of the species and which may require
special management considerations or protection. For example, physical
features might include gravel of a particular size required for
spawning, alkali soil for seed germination, protective cover for
migration, or susceptibility to flooding or fire that maintains
necessary early-successional habitat characteristics. Biological
features might include prey species, forage grasses, specific kinds or
ages of trees for roosting or nesting, symbiotic fungi, or a particular
level of nonnative species consistent with conservation needs of the
listed species. The features may also be combinations of habitat
characteristics and may encompass the relationship between
characteristics or the necessary amount of a characteristic needed to
support the life history of the species. In considering whether
features are essential to the conservation of the species, the Service
may consider an appropriate quality, quantity, and spatial and temporal
arrangement of habitat characteristics in the context of the life-
history needs, condition, and status of the species. These
characteristics include, but are not limited to space for individual
and population growth and for normal behavior; food, water, air, light,
minerals, or other nutritional or physiological requirements; cover or
shelter; sites for breeding, reproduction, or rearing (or development)
of offspring; and habitats that are protected from disturbance.
We derive the specific physical or biological features essential to
the conservation of the island marble butterfly from studies of this
species' habitat, ecology, and life history as described below. We have
determined that the following physical or biological features are
essential to the conservation of the island marble butterfly:
Space for Individual and Population Growth and for Normal Behavior
The island marble butterfly has previously been documented as
having as many as five core populations across San Juan and Lopez
Islands in the San Juan archipelago, but of those five, there is only
one location where it has been consistently detected on an annual basis
since its rediscovery in 1998 at American Camp, part of San Juan Island
National Historical Park. The long-term occupancy of American Camp
indicates that one or more aspects of this site provide the combination
of habitat factors needed by the species. American Camp encompasses
multiple small populations within large expanses of diverse habitat,
including open south-facing slopes, varied broad-scale topographic
features, and low-statured plant communities (Lambert 2011, pp. 151-
152; Lambert 2016a, p. 4). Surface topography (slope and aspect) and
landscape features that have topographic relief (slopes, bluffs, sand
banks, or driftwood berms) are critical to the movement and dispersal
of the island marble butterfly (Lambert 2011, p. 152).
The portion of the park where the island marble butterfly persists
contains an open expanse of prairie and dune habitat greater than 700
ac (283 ha) and is bounded on two sides by marine shoreline. The island
marble butterfly uses landscape features to fly low across the land,
following shallow ridgelines associated with sand dunes, road cuts, and
coastal bluffs. We surmise that the island marble butterfly uses the
lee of rolling hills or hollows in broader expanses of prairie and dune
habitats to facilitate their movements. Therefore, we determine habitat
areas large enough to include broad topographic features (e.g.,
ridgelines, hills, and bluffs) to be physical or biological features
for the island marble butterfly.
At a rangewide scale, the island marble butterfly exhibits
metapopulation dynamics, while on a local scale, ``patchy'' population
dynamics best describes the movement of individuals between suitable
habitat patches (Lambert 2011, pp. 147-148). Specifically, the island
marble butterfly tends to occupy multiple habitat patches within a
larger, heterogeneous area, with some small amount of movement between
suitable habitat patches. Individual butterflies rarely move distances
greater than 0.4 mi (600 m) (Peterson 2010, p. 3). Marked individuals
are nearly always recaptured at the sites where they were marked, with
a single exception when a marked individual was recaptured 1.2 mi (1.9
km) from its site of origin (Peterson 2010, p. 3). Within the last
known occupied site, smaller occupied patches have been observed to
undergo local extirpation events, but the close proximity of nearby
populations within the larger contiguous area has allowed for
recolonization (Lambert 2011, p. 155). Areas large enough to contain
multiple small populations of island marble butterfly that allow for
population connectivity and re-establishment are essential to the
conservation of the species. Therefore, we conclude that areas large
enough to

[[Page 15924]]

support multiple small populations of the species to be a physical or
biological feature essential to the island marble butterfly.
Island marble butterflies tend to fly close to the ground, along
the edges of treed areas or along marine shorelines. Therefore, forest
and open water create natural barriers to movement (Lambert 2011, pp.
49, 50). Male island marble butterflies fly low (approximately 5 ft
(1.5 m) above the ground) and follow ridgelines, bluffs, road-cuts,
trail edges, fence lines, and shrub or forest edges in search of mates
(Lambert 2011, pp. 47-48). Female island marble butterflies have been
observed to fly in low (approximately 3 ft (1 m) above the ground),
wide (330-980 ft (100-500 m)) circles above the ground searching for
suitable host plants upon which to lay their eggs (Lambert 2011, p.
49). We conclude that large open areas with few trees are a physical or
biological feature for the island marble butterfly.
Based on the best information available, we estimate that the
conservation of the island marble butterfly is best supported by open,
primarily treeless areas with short-statured forb- and grass-dominated
vegetation. Areas should be large enough to allow for the inclusion of
diverse topographic features and habitat types, including sites for
mating, egg laying, feeding, refugia (places to safely harbor), and
diapause locations, and should support multiple discrete occupied
habitat patches, which increases the likelihood of recolonization if
local extinction takes place. Therefore, we conclude that open,
primarily treeless habitat areas that are large enough to support
multiple, small populations and that include broad topographic features
such as ridgelines, hills, and bluffs are physical or biological
features essential to the conservation of the island marble butterfly.
Food, Water, Air, Light, Minerals, or Other Nutritional or
Physiological Requirements
The island marble butterfly needs larval and adult food resources
in order to complete its life cycle: Larval host plants (food plants
required by the immature stages of the butterfly) and nectar plants for
the adults. The island marble butterfly has three known larval host
plants, all in the mustard family (Brassicaceae). One is native,
Menzies' pepperweed, and two are nonnative--field mustard and tumble
mustard (Miskelly 2004, pp. 33, 38; Lambert 2011, p. 2). These three
larval host plants are essential components of habitat for the island
marble butterfly.
All three larval host plants occur in open grass- and forb-
dominated plant communities, but each species is most robust in one of
three specific habitat types, with little overlap: Menzies' pepperweed
at the edge of low-lying coastal lagoon habitat; field mustard in
upland prairie habitat, disturbed fields, and disturbed soils,
including soil piles from construction; and tumble mustard in sand dune
habitat (Miskelly 2004, p. 33; Miskelly and Potter 2009, p. 9; Lambert
2011, pp. 24, 121-123). While each larval host plant can occur in each
of the three habitat types referenced above, female island marble
butterflies typically lay eggs on only the most robust host plants in
each aforementioned habitat type (Miskelly 2004, p. 33; Lambert 2011,
pp. 24, 41, 50, 55-57, 121-123).
We conclude that the presence of Menzies' pepperweed, field
mustard, or tumble mustard is a physical or biological feature upon
which the island marble butterfly depends.
Adults primarily forage for nectar on their larval host plants
(Potter 2015e, pers. Comm.). They also use a variety of other nectar
plants that flower during the island marble butterfly's flight period,
which is generally from mid-April to mid- to late-June. Adults have
been observed to nectar on yellow sand verbena, yarrow, small-flowered
fiddleneck, American sea rocket, field chickweed, common stork's bill,
dovefoot geranium, hairy cat's ear, common lomatium, seashore lupine,
common forget-me-not, California buttercup, trailing blackberry,
dandelion, death camas, and Howell's Brodiaea (Miskelly 2004, p. 33;
Pyle 2004, pp. 23-26, 33; Miskelly and Potter 2005, p. 6; Lambert 2011,
p. 120; Vernon and Weaver 2012, Appendix 12; Lambert 2015a, p. 2,
Lambert 2015b, in litt.). Of these additional nectar resources, island
marble butterflies are most frequently observed feeding on yellow sand
verbena, small-flowered fiddleneck, and field chickweed (Potter 2015e,
pers. comm.). We conclude that adult nectar resources, including, but
not limited to those listed here, are a physical or biological feature
upon which the island marble butterfly depends.
Like many animals that rely on external sources of body heat
(ectotherms), the island marble butterfly is more active at warmer
temperatures; for this species, this generally means temperatures that
are higher than 55 degrees Fahrenheit (F) (13 degrees Celsius (C)).
This leads to adult (winged) island marble butterflies being most
active between the hours of 10 a.m. and 4 p.m. The island marble
butterfly relies upon solar radiation for the warmth that drives their
development, mate-finding, and reproduction. We conclude that exposure
to the sun provided by open, primarily treeless areas with some south-
facing slopes and short-statured vegetation is a physical or biological
feature upon which the island marble butterfly depends.
We consider open sunlit areas containing at least one species of
larval host plant, Menzies' pepperweed, field mustard, and/or tumble
mustard with both flower buds and blooms between the months of May
through July to be physical or biological features of island marble
butterfly habitat. We additionally consider the presence of adult
nectar plants in flower to be a physical or biological feature of
island marble butterfly habitat.
Sites for Breeding, Reproduction, or Rearing (or Development) of
Offspring
Male island marble butterflies are attracted to white and may
investigate white picket fences, white lines on surface roads, or other
white objects while searching for a mate (Lambert 2011, p. 47). The
island marble butterfly primarily uses short-statured, white-flowering
plants such as field chickweed as sites for mate attraction and mating
(Lambert 2014b, p. 17). We conclude that the presence of short-
statured, white-flowering plants during the flight period (generally
from mid-April to mid- to late-June) for the island marble butterfly to
be a physical or biological feature of the island marble butterfly
habitat.
Once mated, gravid female island marble butterflies seek out larval
host plants at an optimal growth stage for egg laying (recently hatched
caterpillars require tender plant parts, such as immature flower buds,
because their mouthparts are not developed enough to eat hardened plant
matter) (Lambert 2011, pp. 9-10). Larval host plant flowering phenology
(timing of flower opening) is important for island marble butterflies.
If the plants emerge too early, there may not be enough tissue at the
right stage available for the larvae to go through their developmental
phases. If the plants emerge too late, female butterflies may not
recognize the larval host plants as suitable sites to lay eggs.
Female island marble butterflies carefully gauge the suitability of
each larval host plant, preferentially selecting plants that possess
both flowers and buds to lay eggs on. Plants with greater than 50
percent of their flowers in bloom are more likely to be selected than
plants in an earlier (less than 50 percent of flowers in bloom) or
later

[[Page 15925]]

developmental stage (Lambert 2011, pp. 59-60). Female island marble
butterflies tend to lay eggs singly on the immature buds of the flowers
of their larval host plants, rarely laying eggs on inflorescences that
are already occupied by eggs or larvae (Lambert 2011, pp. 51-57).
Female island marble butterflies prefer larval host plants growing in
low-density patches with less than one plant per meter square and tend
to choose plants that are along the outer edge of a patch of larval
host plants rather than in areas with a high density of host plants
(Lambert 2011, pp. 53, 68-69; Lambert 2015d, p. 9). Additionally, host
plant phenology (timing of development) plays a significant role in
determining where females lay eggs. Low- to medium-density larval host
plants for egg-laying and larval development, with both flower buds and
blooms on them between the months of May through July, are a physical
or biological feature of island marble butterfly habitat.
After hatching, larvae of the island marble butterfly rapidly
progress through five instars (larval growth stages) and have been
documented to then move up to 13 ft (4 m) from their larval host plant
to nearby standing vegetation (usually tall grasses) to pupate (Lambert
2011, p. 19). Island marble butterfly larvae use nearby vegetation as
bridges to other plants and appear to avoid being close to the ground
while searching for a safe site to form a chrysalis (pupal casing)
(Lambert 2011, pp. 20-21). Therefore, we find that the presence of
larval host plants, in complement with tall, standing vegetation that
provides the structure necessary to allow mature larvae to cross to a
safe pupation site, is a physical or biological feature of island
marble butterfly habitat.
Habitats That Are Protected From Disturbance or Are Representative of
the Historical, Geographical, and Ecological Distributions of a Species
The island marble butterfly spends approximately 300 days in
diapause (a form of dormancy) as a chrysalis (pupa) before undergoing
metamorphosis to emerge as a winged adult the following spring. Unlike
other butterfly species that may diapause underground or,
alternatively, rapidly advance from egg to winged-adult and over-winter
in an adult phase, the island marble butterfly enters diapause
aboveground and very close to where it hatched. During diapause, the
island marble butterfly is vulnerable to any activity such as
trampling, mowing, harvesting, grazing, or plowing that may disturb or
destroy the vegetative structure to which a larva has attached its
pupal casing. The larval host plants for the island marble butterfly
are annual (or biennial) and habitat patches for the island marble
butterfly do not tend to persist in the same area continuously over
time. Leaving the vegetation near where larval host plants established
in the spring until mid-summer the following year provides a safe place
for the island marble butterfly chrysalids to harbor until they emerge.
Therefore, we find that sufficient areas of undisturbed vegetation
surrounding larval host plants that are left standing for a sufficient
period of time in order for the island marble butterfly to complete its
life cycle is a physical or biological feature of island marble
butterfly habitat.
Summary of Essential Physical or Biological Features
We have determined that the following physical or biological
features of the areas on San Juan Island, Washington, that are
essential to the conservation of the island marble butterfly are:
(a) Open, primarily treeless areas with short-statured forb- and
grass-dominated vegetation that include diverse topographic features
such as ridgelines, hills, and bluffs for patrolling, dispersal
corridors between habitat patches, and some south-facing terrain. Areas
must be large enough to allow for the development of patchy-population
dynamics, allowing for multiple small populations to establish within
the area.
(b) Low- to medium-density larval host plants for egg-laying and
larval development, with both flower buds and blooms on them between
the months of May through July. Larval host plants may be any of the
following: Brassica rapa, Sisymbrium altissimum, or Lepidium
virginicum.
(c) Adult nectar resources in flower and short-statured, white-
flowering plants in bloom used for mate-finding, which may include, but
are not limited to Abronia latifolia (yellow sand verbena), Achillea
millefolium (yarrow), Amsinckia menziesii (small-flowered fiddleneck),
Cakile edentula (American sea rocket), Cerastium arvense (field
chickweed), Erodium cicutarium (common stork's bill), Geranium molle
(dovefoot geranium), Hypochaeris radicata (hairy cat's ear), Lomatium
utriculatum (common lomatium), Lupinus littoralis (seashore lupine),
Myosotis discolor (common forget-me-not), Ranunculus californicus
(California buttercup), Rubus ursinus (trailing blackberry), Taraxacum
officinale (dandelion), Toxicoscordion venenosum (death camas, formerly
known as Zigadenus venenosus), and Triteleia grandiflora (Howell's
Brodiaea, formerly Brodiaea howellii).
(d) Areas of undisturbed vegetation surrounding larval host plants
sufficient to provide secure sites for diapause and pupation. The
vegetation surrounding larval host plants must be left standing for a
sufficient period of time for the island marble butterfly to complete
its life cycle.

Special Management Considerations or Protection

When designating critical habitat, we assess whether the specific
areas within the geographical area occupied by the species at the time
of listing contain features which are essential to the conservation of
the species and which may require special management considerations or
protection. Because the island marble butterfly depends on vegetation
that requires disturbance and open areas to establish, special
management may be necessary to both maintain low-level disturbance and
to prevent the invasion of weedy native and nonnative plant species,
such as Douglas fir, Mediterranean pasture grasses, and thistle.
Beneficial special management activities could include annual burning
to remove standing vegetation and seedlings and reduce seed set of
nonnative plant species. Additionally, the application of selective
herbicides to combat specific invasive plants may also prove useful in
vegetation management. For some weedy species, hand-pulling can be an
effective vegetation management tool, if staffing and resources allow.
Special management considerations within the proposed critical
habitat unit may include protection of larval host plants from
herbivory by browsing deer, European rabbits, and brown garden snails.
These herbivores constitute the primary threat to the larval host
plants upon which the island marble butterfly depends in the proposed
designation. Special management actions that could ameliorate the
threat of herbivory by deer, European rabbits, and brown garden snails
could include lethal control methods, such as targeted hunting or
professional removal. For deer, exclusion fencing increases the
survivorship of both larval host plants and the island marble butterfly
in the fenced areas, but the fences are difficult to erect and maintain
and provide a host of other challenges for the land management
agencies. Additionally, exclusion fencing does nothing to reduce the
number of deer, which is the primary cause of the intense browsing
pressure on the larval host plants for the island marble butterfly
(Lambert 2011,

[[Page 15926]]

pp. 85-104, 127; Lambert 2014a, p. 3; Lambert 2015d, pp. 14-18).
Fencing is not effective against European rabbits and brown garden
snails.

Criteria Used To Identify Critical Habitat

As required by section 4(b)(2) of the Act, we use the best
scientific data available to designate critical habitat. When we are
determining which areas should be designated as critical habitat, our
primary source of information is generally the information developed
during the listing process for the species. Additional information
sources may include the recovery plan for the species, articles in
peer-reviewed journals, conservation plans developed by States and
counties, scientific status surveys and studies, biological
assessments, other unpublished materials, or experts' opinions or
personal knowledge. In this case, we used existing occurrence data for
the island marble butterfly and information on the habitat and
ecosystems upon which it depends. These sources of information
included, but were not limited to:
(1) Data used to prepare the proposed rule to list the species;
(2) Information from biological surveys;
(3) Various agency reports and databases;
(4) Information from NPS and other cooperators;
(5) Information from species experts;
(6) Data and information presented in academic research theses; and
(7) Regional Geographic Information System (GIS) data (such as
species occurrence data, land use, topography, aerial imagery, soil
data, and land ownership maps) for area calculations and mapping.

Areas Occupied at the Time of Listing

In accordance with the Act and our implementing regulations at 50
CFR 424.12(b) we reviewed available information pertaining to the
habitat requirements of the species, identified specific areas within
the geographical area occupied by the species at the time of listing
and examined whether we could identify any specific areas outside the
geographical area occupied by the species to be considered for
designation as critical habitat. In this case, since we are proposing
listing concurrently with the proposed designation of critical habitat,
all areas presently occupied by the island marble butterfly constitute
those areas occupied at the time of listing.
We plotted the known locations of the island marble butterfly where
they occur in Washington using 2015 National Agriculture Imagery
Program (NAIP) digital imagery in ArcGIS, version 10.4 (Environmental
Systems Research Institute, Inc.), a computer geographic information
system program, and determined that the currently occupied areas
contain the physical or biological features needing special management,
as discussed above. We also analyzed the appropriate quantity and
spatial arrangement of these features in the context of the life
history, status and conservation needs of the species.
Survey effort for the island marble butterfly has not been
consistent spatially or temporally. Island-wide surveys of San Juan and
Lopez Islands were discontinued by WDFW in 2012, due to decreased
detections and the lack of larval host plants in previously occupied
areas across both islands. In 2015, the Service funded an island-wide
survey of San Juan, and no occurrences were documented outside of the
known occupied area centered on American Camp at the south end of San
Juan Island. The last survey of Lopez Island was conducted in 2012, and
a single larva was observed. There have been no reports of island
marble butterflies from Lopez Island since 2012.
Therefore, the Service considers areas to be occupied at the time
of listing if there are occurrence records within those areas within
the last 5 years or if areas adjacent to known occupied areas have the
physical or biological features upon which the island marble butterfly
depends and there are no barriers to dispersal. It is reasonable to
conclude that the species regularly occurs in such areas because of the
species' population dynamics and frequent movement between habitat
patches, as discussed above. Occurrence records are deemed credible if
recorded by a Federal, State, or contract biologist, or a qualified
surveyor for the island marble butterfly.
We have also determined that all of these occupied areas (areas
with documented occurrences as well as adjacent areas containing
suitable habitat and where there are no barriers to dispersal) contain
one or more of the essential physical or biological features. For these
reasons and due to the restricted range of the island marble butterfly,
we determined that all known occupied areas should be proposed for
critical habitat designation. The only known occupied area is centered
on American Camp at San Juan Island National Historical Park and
includes adjacent lands to the east and the west of the National Park
that are owned and managed by BLM, WDNR, San Juan County, Washington
State Parks and Recreation, and private individuals.
In summary, we are proposing for designation of critical habitat
lands that we have determined are occupied at the time of listing and
contain one or more of the physical or biological features to support
life-history processes essential to the conservation of the species.
The one unit proposed for designation contains all of the identified
physical or biological features and supports multiple life-history
processes.
When determining the proposed critical habitat boundary, we made
every effort to avoid including developed areas such as lands covered
by buildings, pavement (such as parking lots and roads), and other
structures because such lands lack physical or biological features
necessary for the island marble butterfly. The scale of the map we
prepared under the parameters for publication within the Code of
Federal Regulations may not reflect the exclusion of such developed
lands. Any such lands inadvertently left inside critical habitat
boundaries shown on the map of this proposed rule have been excluded by
text in the proposed rule and are not proposed for designation as
critical habitat. Therefore, if the critical habitat is finalized as
proposed, a Federal action involving these lands would not trigger
section 7 consultation with respect to critical habitat and the
requirement of no adverse modification unless the specific action would
affect the physical or biological features in the adjacent critical
habitat. Please note that we specifically include road margins and
shoulders in the critical habitat designation, as the island marble
butterfly larval host plants often establish in these disturbed areas
and may be used by the island marble butterfly for egg-laying and
development. Special management considerations for road margins and
shoulders may apply.
The critical habitat designation is defined by the map, as modified
by any accompanying regulatory text, presented at the end of this
document in the Proposed Regulation Promulgation section. We include
more detailed information on the boundaries of the critical habitat
designation in the preamble of this document. We will make the
coordinates or plot points or both on which the map is based available
to the public on http://www.regulations.gov at Docket No. FWS-R1-ES-
2016-0145, on our website at https://www.fws.gov/wafwo/, and by
appointment at the Service's Washington Fish and Wildlife Office (see
FOR FURTHER INFORMATION CONTACT, above).

[[Page 15927]]

Areas Outside of the Geographic Range at the Time of Listing

We are not currently proposing to designate any areas outside the
geographical area occupied by the species. While we know the
conservation of the species will depend on increasing the number and
distribution of populations of the island marble butterfly, not all of
its historical range will be essential to the conservation of the
species, and we are unable to delineate the specific unoccupied areas
that are essential at this time. Sites both within and outside of the
central valleys of San Juan and Lopez Islands were previously occupied
by the island marble butterfly. A number of areas within and outside of
these valleys continue to contain some or could develop many of the
physical and biological features upon which the species depends, though
the best available scientific data indicate all these areas are
currently unoccupied. The areas of the central valleys with the
potential to support the physical and biological features continue to
be important to the overall conservation strategy for the island marble
butterfly. However, due to the ephemeral and patchy nature of island
marble butterfly habitat, only some of these areas within these larger
central valley landscapes will likely be essential to the species'
long-term persistence and conservation because of the ease with which
field mustard recruits and the uncertainty associated with habitat
patch longevity at any one site.
In addition, the specific areas essential to the species'
conservation within these broader landscapes are not identifiable at
this time. This is due to our current limited understanding regarding
the ideal configuration for the development of future habitat patches
to support the island marble butterfly's persistence, the ideal size
and number of these habitat patches, and how these habitat patches may
naturally evolve within and persist on the landscape. Finally, the
specific areas needed for conservation will depend in part on landowner
willingness to restore and maintain the species' habitat in these
areas.
Consequently, the Service is considering proposing the future
establishment of one or more experimental populations (such as, but not
limited to, those provided for under section 10(j) of the Act) within
these broad geographic areas should the island marble butterfly be
listed under the Act. Section 10(j) of the Act authorizes the Service,
by rulemaking, to establish new populations of listed species that are
within the species' historical range but outside its current natural
range. If designated a nonessential population, a special rule may
minimize restrictions on landowners. Any such regulation would, to the
maximum extent practicable, represent an agreement between the Service
and affected landowners and government agencies (50 CFR 17.82(d)).
Additionally, the Service, in collaboration with WDFW and private
landowners, is working on the development of a programmatic candidate
conservation agreement with assurances (CCAA). A CCAA is a voluntary
conservation program to encourage willing landowners to partner with us
to create, enhance, and maintain habitat that could be used by island
marble butterfly on their lands while providing enrolled landowners
with regulatory assurances should the species be listed. For more
information, please contact the Washington Fish and Wildlife Office
Listing and Recovery Division Manager (360-753-9440).

Proposed Critical Habitat Designation

The proposed critical habitat area described below constitutes our
current best assessment of the areas that meet the definition of
critical habitat for the island marble butterfly. The island marble
butterfly critical habitat unit is currently occupied and therefore
considered occupied at the time of listing.

Table 1--Proposed Critical Habitat for the Island Marble Butterfly
[Area estimates reflect all land within critical habitat unit
boundaries]
------------------------------------------------------------------------
Size of unit
Critical habitat unit Land ownership by in acres
type (hectares)
------------------------------------------------------------------------
Island marble butterfly proposed NPS................. 718 (291)
critical habitat. BLM................. 19 (8)
DHS................. 5 (2)
WDNR and SJCLB...... 1 (0.4)
WDNR................ 37 (15)
SJCPD............... 30 (12)
Private............. 2 (0.8)
---------------
Total......................... .................... 812 (329)
------------------------------------------------------------------------
Note: Area sizes may not sum due to rounding. NPS = National Park
Service, BLM = Bureau of Land Management, DHS = Department of Homeland
Security (Coast Guard), WDNR = Washington Department of Fish and
Wildlife, SJCLB = San Juan County Land Bank, SJCPD = San Juan County
Parks Department.

The proposed critical habitat designation consists of 812 ac (329
ha) of land at the south end of San Juan Island, with San Juan Island
National Historical Park (NPS) being the largest landholder of 718 ac
(291 ha). The Bureau of Land Management (BLM) owns and manages 19 ac (8
ha), Washington Department of Natural Resources (WDNR) owns and manages
37 ac (15 ha) at Cattle Point, the Department of Homeland Security owns
5 ac (2 ha), WDNR and the San Juan County Land Bank (SJCLB) jointly own
1 ac (0.4 ha), San Juan County Parks Department owns 30 ac (12 ha), and
approximately 2 ac (0.8 ha) is in private ownership. The proposed
critical habitat designation is centered on the American Camp portion
of San Juan Island National Historical Park, which is owned and managed
by the National Park Service, but includes adjacent lands both to the
east and the west of National Park Service lands. Boundaries for the
critical habitat unit follow the open, generally treeless habitat that
the island marble butterfly relies upon during its flight period for
mate-finding, reproduction, feeding, and dispersal.
The entirety of the proposed critical habitat unit is within the
geographical area occupied at the time of listing. The proposed
designation contains all of the physical or biological features
required to support the island marble butterfly.

[[Page 15928]]

The proposed critical habitat designation is almost entirely conserved
for use by or for the benefit of the public and is heavily used for
recreation, primarily in the form of day hiking on easy trails. NPS has
maintained a conservation agreement for the island marble butterfly
with the Service since 2006, although the most recent conservation
agreement has lapsed and the next version has not yet been signed by
both parties. Regardless, as the largest landholder within the proposed
critical habitat unit, NPS continues to support and participate in
ongoing research integral to the conservation of the island marble
butterfly. BLM, DHS, WDNR, SJCLB, and San Juan County Parks are all
engaged in the conservation of the island marble butterfly and meet
with the Service multiple times annually to coordinate conservation
efforts.
Within the proposed critical habitat designation, all of the
current threats to the island marble butterfly are present. Please see
Determination of Species' Status, above, for a summary of the threats
and Special Management Considerations or Protection for additional
recommendations.

Effects of Critical Habitat Designation

Section 7 Consultation

Section 7(a)(2) of the Act requires Federal agencies, including the
Service, to ensure that any action they fund, authorize, or carry out
is not likely to jeopardize the continued existence of any endangered
species or threatened species or result in the destruction or adverse
modification of designated critical habitat of such species. In
addition, section 7(a)(4) of the Act requires Federal agencies to
confer with the Service on any agency action which is likely to
jeopardize the continued existence of any species proposed to be listed
under the Act or result in the destruction or adverse modification of
proposed critical habitat.
We published a final regulation with a new definition of
destruction or adverse modification on February 11, 2016 (81 FR 7214).
Destruction or adverse modification means a direct or indirect
alteration that appreciably diminishes the value of critical habitat
for the conservation of a listed species. Such alterations may include,
but are not limited to, those that alter the physical or biological
features essential to the conservation of a species or that preclude or
significantly delay development of such features.
If a Federal action may affect a listed species or its critical
habitat, the responsible Federal agency (action agency) must enter into
consultation with us. Examples of actions that are subject to the
section 7 consultation process are actions on State, tribal, local, or
private lands that require a Federal permit (such as a permit from the
U.S. Army Corps of Engineers under section 404 of the Clean Water Act
(33 U.S.C. 1251 et seq.) or a permit from the Service under section 10
of the Act) or that involve some other Federal action (such as funding
from the Federal Highway Administration, Federal Aviation
Administration, or the Federal Emergency Management Agency). Federal
actions not affecting listed species or critical habitat, and actions
on State, tribal, local, or private lands that are not federally funded
or authorized, do not require section 7 consultation.
Section 7 consultation concludes with issuance of:
(1) A concurrence letter for Federal actions that may affect, but
are not likely to adversely affect, listed species or critical habitat;
or
(2) A biological opinion for Federal actions that are likely to
adversely affect listed species or critical habitat.
If we issue a biological opinion concluding that a project is
likely to jeopardize the continued existence of a listed species and/or
destroy or adversely modify critical habitat, we provide reasonable and
prudent alternatives to the project, if any are identifiable, that
would avoid the likelihood of jeopardy and/or destruction or adverse
modification of critical habitat. We define ``reasonable and prudent
alternatives'' (at 50 CFR 402.02) as alternative actions identified
during consultation that:
(1) Can be implemented in a manner consistent with the intended
purpose of the action,
(2) Can be implemented consistent with the scope of the Federal
agency's legal authority and jurisdiction,
(3) Are economically and technologically feasible, and
(4) Would, in the Director's opinion, avoid the likelihood of
jeopardizing the continued existence of the listed species and/or avoid
the likelihood of destroying or adversely modifying critical habitat.
Reasonable and prudent alternatives can vary from slight project
modifications to extensive redesign or relocation of the project. Costs
associated with implementing a reasonable and prudent alternative are
similarly variable.
Regulations at 50 CFR 402.16 require Federal agencies to reinitiate
consultation on previously reviewed actions in instances where we have
listed a new species or subsequently designated critical habitat that
may be affected and the Federal agency has retained discretionary
involvement or control over the action (or the agency's discretionary
involvement or control is authorized by law). Consequently, Federal
agencies sometimes may need to request reinitiation of consultation
with us on actions for which formal consultation has been completed, if
those actions with discretionary involvement or control may affect
subsequently listed species or designated critical habitat.

Application of the ``Adverse Modification'' Standard

The key factor related to the adverse modification determination is
whether, with implementation of the proposed Federal action, the
affected critical habitat would continue to serve its intended
conservation role for the species. Activities that may destroy or
adversely modify critical habitat are those that result in a direct or
indirect alteration that appreciably diminishes the value of critical
habitat for the conservation of the island marble butterfly. Such
alterations may include, but are not limited to, those that alter the
physical or biological features essential to the conservation of this
species or that preclude or significantly delay development of such
features. As discussed above, the role of critical habitat is to
support physical or biological features essential to the conservation
of a listed species and provide for the conservation of the species.
Section 4(b)(8) of the Act requires us to briefly evaluate and
describe, in any proposed or final regulation that designates critical
habitat, activities involving a Federal action that may destroy or
adversely modify such habitat, or that may be affected by such
designation.
Activities that may affect island marble butterfly critical
habitat, when carried out, funded, or authorized by a Federal agency,
would result in consultation. These activities may include, but are not
limited to:
(1) Actions that destroy the habitat within the critical habitat
unit. Such activities could include, but are not limited to, new
infrastructure developments, planting forests in historical prairie, or
large paving projects. These activities could disrupt dispersal, mate
finding, and patchy population dynamics, as well as prevent the
recruitment of future habitat.
(2) Actions that would temporarily or permanently remove host
plants from areas within the critical habitat unit that

[[Page 15929]]

were otherwise phenologically and spatially available for use by the
species. Such activities could include, but are not limited to, mowing,
burning, or applying herbicide to host plants leading up to or during
the flight season. These activities could reduce the quantity or
distribution of oviposition sites available to the species.
(3) Actions that would temporarily or permanently remove nectar
resources or plants used for mate finding from areas within the
critical habitat unit that were otherwise phenologically and spatially
available for use by the species. Such activities could include, but
are not limited to, mowing, burning, or applying herbicide to nectar or
mate-finding plants leading up to or during the flight season. These
activities could reduce nectaring opportunities or disrupt mate
finding, both of which could reduce fecundity.
(4) Actions that would physically disturb appropriate areas for
diapause and pupation. Such activities could include, but are not
limited to, mowing, trampling, grazing, or burning between flight
seasons. These activities could also kill island marble butterflies in
diapause as pupae.

Exemptions

Application of Section 4(a)(3) of the Act

Section 4(a)(3)(B)(i) of the Act (16 U.S.C. 1533(a)(3)(B)(i))
provides that: ``The Secretary shall not designate as critical habitat
any lands or other geographic areas owned or controlled by the
Department of Defense, or designated for its use, that are subject to
an integrated natural resources management plan [INRMP] prepared under
section 101 of the Sikes Act (16 U.S.C. 670a), if the Secretary
determines in writing that such plan provides a benefit to the species
for which critical habitat is proposed for designation.'' There are no
Department of Defense lands with a completed INRMP within the proposed
critical habitat designation.

Consideration of Impacts Under Section 4(b)(2) of the Act

Section 4(b)(2) of the Act states that the Secretary shall
designate and make revisions to critical habitat on the basis of the
best available scientific data after taking into consideration the
economic impact, national security impact, and any other relevant
impact of specifying any particular area as critical habitat. The
Secretary may exclude an area from critical habitat if he determines
that the benefits of such exclusion outweigh the benefits of specifying
such area as part of the critical habitat, unless he determines, based
on the best scientific data available, that the failure to designate
such area as critical habitat will result in the extinction of the
species. In making that determination, the statute on its face, as well
as the legislative history, are clear that the Secretary has broad
discretion regarding which factor(s) to use and how much weight to give
to any factor. We are not proposing any areas for exclusion from this
critical habitat designation.

Consideration of Economic Impacts

Section 4(b)(2) of the Act and its implementing regulations require
that we consider the economic impact that may result from a designation
of critical habitat. To assess the probable economic impacts of a
designation, we must first evaluate specific land uses or activities
and projects that may occur in the area of the critical habitat. We
then evaluate the impacts that a specific critical habitat designation
may have on restricting or modifying specific land uses or activities
for the benefit of the species and its habitat within the areas
proposed. We then identify which conservation efforts may be the result
of the species being listed under the Act versus those attributed
solely to the designation of critical habitat for this particular
species. The probable economic impact of a proposed critical habitat
designation is analyzed by comparing scenarios both ``with critical
habitat'' and ``without critical habitat.'' The ``without critical
habitat'' scenario represents the baseline for the analysis, which
includes the existing regulatory requirements imposed on landowners,
managers, or other resource users potentially affected by the
designation of critical habitat (e.g., under the Federal listing as
well as other Federal, State, and local regulations). The baseline,
therefore, represents the costs of all efforts attributable to the
listing of the species under the Act (i.e., conservation of the species
and its habitat incurred regardless of whether critical habitat is
designated). The ``with critical habitat'' scenario describes the
incremental impacts associated specifically with the designation of
critical habitat for the species. The incremental conservation efforts
and associated impacts would not be expected without the designation of
critical habitat for the species. In other words, the incremental costs
are those attributable solely to the designation of critical habitat,
above and beyond the baseline costs. These are the costs we use when
evaluating the benefits of inclusion and exclusion of particular areas
from the final designation of critical habitat should we choose to
conduct a discretionary 4(b)(2) exclusion analysis.
For this particular designation, we developed an Incremental
Effects Memorandum (IEM) considering the probable incremental economic
impacts that may result from this proposed designation of critical
habitat. The information contained in our IEM was then used to develop
a screening analysis of the probable effects of the designation of
critical habitat for the island marble butterfly (Industrial Economics,
Incorporated 2017). We began by conducting a screening analysis of the
proposed designation of critical habitat in order to focus our analysis
on the key factors that would be most likely to result in incremental
economic impacts. The purpose of the screening analysis is to filter
out the geographic areas in which the critical habitat designation is
unlikely to result in probable incremental economic impacts. In
particular, the screening analysis considers baseline costs (i.e.,
absent critical habitat designation) and includes probable economic
impacts where land and water use may be subject to conservation plans,
land management plans, best management practices, or regulations that
protect the habitat area as a result of the Federal listing status of
the species. The screening analysis filters out particular areas of
critical habitat that are already subject to such protections and are,
therefore, unlikely to incur incremental economic impacts. Ultimately,
the screening analysis allows us to focus our analysis on evaluating
the specific areas or sectors that may incur incremental economic
impacts as a result of the designation. The screening analysis also
assesses whether units are unoccupied by the species and may require
additional management or conservation efforts as a result of the
critical habitat designation for the species which may incur
incremental economic impacts. This screening analysis combined with the
information contained in our IEM are what we consider our draft
economic analysis (DEA) of the proposed critical habitat designation
for the island marble butterfly and is summarized in the narrative
below.
Executive Orders (E.O.s) 12866 and 13563 direct Federal agencies to
assess the costs and benefits of available regulatory alternatives in
quantitative (to the extent feasible) and qualitative terms. Consistent
with the E.O. regulatory analysis requirements, our effects analysis
under the Act may take into consideration impacts to both directly and
indirectly affected entities, where practicable and reasonable. If

[[Page 15930]]

sufficient data are available, we assess to the extent practicable the
potential impacts to both directly and indirectly affected entities. As
part of our screening analysis, we considered the types of economic
activities that are likely to occur within the areas likely affected by
the critical habitat designation. In our evaluation of the potential
incremental economic impacts that may result from the proposed
designation of critical habitat for the island marble butterfly, first
we identified, in the IEM dated July 5, 2017, potential incremental
economic impacts associated with the following categories of
activities: (1) Federal lands management (by National Park Service and
Bureau of Land Management): Prairie restoration, island marble
butterfly habitat restoration, island marble butterfly recovery
projects, transportation management, and new facility construction; (2)
State lands including lands jointly managed with the San Juan County
Land Bank: Native prairie restoration, habitat restoration projects to
benefit island marble butterfly prairie habitat, potential future
infrastructure projects such as resurfacing of trail/pathways, and
replacement of interpretive signs; and (3) County-owned lands:
Transportation projects/road work. We considered each industry or
category individually. Additionally, we considered whether these
activities have any Federal involvement. Critical habitat designation
generally will not affect activities that do not have any Federal
involvement; under the Act, designation of critical habitat only
affects activities conducted, funded, permitted, or authorized by
Federal agencies. If we finalize the proposed listing of this species,
Federal agencies will be required to consult with the Service under
section 7 of the Act on activities they fund, permit, or implement that
may affect the species in areas where the island marble butterfly is
present. If we finalize this proposed critical habitat designation,
consultations to avoid the destruction or adverse modification of
critical habitat would be incorporated into the consultation process.
In our IEM, we attempted to clarify the distinction between the
effects that will result from the species being listed and those
attributable to the critical habitat designation (i.e., difference
between the jeopardy and adverse modification standards) for the island
marble butterfly's critical habitat. The following specific
circumstances in this case help to inform our evaluation: (1) The
essential physical or biological features identified for critical
habitat are the same features essential for the life requisites of the
species and (2) any actions that would result in effects that would
likely jeopardize the island marble butterfly would also be likely to
adversely affect the essential physical or biological features of
critical habitat. The IEM further explains these circumstances. This
evaluation of the incremental effects has been used as the basis to
evaluate the potential incremental economic impacts of this proposed
designation of critical habitat.
The proposed critical habitat designation for the island marble
butterfly is comprised of a single unit and is considered occupied. We
are not proposing to designate any units of unoccupied habitat. The
proposed critical habitat designation consists of 812 ac (329 ha) and
is owned and managed by NPS, BLM, DHS, WDNR, San Juan County, and
private landowners. In these areas, any actions that may affect the
species or its habitat would also affect designated critical habitat
and it is unlikely that any additional conservation efforts would be
recommended to address the adverse modification standard over and above
those recommended as necessary to avoid jeopardizing the continued
existence of the island marble butterfly. Therefore, the potential
incremental economic impacts of the island marble butterfly critical
habitat designation are expected to be limited to administrative costs.
The entities most likely to incur incremental costs are parties to
section 7 consultations, including Federal action agencies and, in some
cases, third parties, most frequently State agencies or municipalities.
Our analysis of economic impacts makes the following assumptions about
consultation activity over the next 20 years, most of which are more
likely to overstate than understate potential impacts: Two programmatic
consultations will occur with NPS; two programmatic consultations will
occur with BLM; one formal or informal consultation will occur with
either NPS or BLM annually; one formal or informal programmatic intra-
Service consultation for funding conservation efforts on State lands
will occur; and two formal or informal consultations with the Federal
Highway Administration will occur related to roads on County-owned
lands.
This may overstate the number of consultations that will occur
given available information on forecast activity. As stated above, we
anticipate that conservation efforts needed to avoid adverse
modification are likely to be the same as those needed to avoid impacts
to the species itself. As such, costs of critical habitat designation
for the island marble butterfly are anticipated to be limited to
administrative costs. We anticipate that the incremental administrative
costs of addressing adverse modification of the island marble butterfly
critical habitat in a section 7 consultation will be minor.
Total annualized incremental costs of critical habitat designation
for the island marble butterfly are anticipated to be less than
$150,000 over the next 20 years, or approximately $10,000 annually. The
incremental administrative burden resulting from the designation of
critical habitat for the island marble butterfly is not anticipated to
reach $100 million in any given year based on the anticipated annual
number of consultations and associated consultation costs, which are
not expected to exceed $10,000 in most years.
As we stated earlier, we are soliciting data and comments from the
public on the DEA, as well as all aspects of the proposed rule and our
required determinations. We may revise the proposed rule or supporting
documents to incorporate or address information we receive during the
public comment period. In particular, we may exclude an area from
critical habitat if we determine that the benefits of excluding the
area outweigh the benefits of including the area, provided the
exclusion will not result in the extinction of this species.

Exclusions

Exclusions Based on Economic Impacts

Under section 4(b)(2) of the Act, we consider the economic impacts
of specifying any particular area as critical habitat. In order to
consider economic impacts, we prepared an analysis of the probable
economic impacts of the proposed critical habitat designation and
related factors. Potential land-use sectors that may be affected
include conservation and recreation lands. In our DEA, we did not
identify any ongoing or future actions that would warrant additional
recommendations or project modifications to avoid adversely modifying
critical habitat above those we would recommend for avoiding jeopardy
to the species, and we anticipate minimal change in management at San
Juan Island National Historical Park due to the designation of critical
habitat for the island marble butterfly.
During the development of a final designation, we will consider any
additional economic impact information we receive during the public
comment period, and as such, areas may be

[[Page 15931]]

excluded from the final critical habitat designation under section
4(b)(2) of the Act and our implementing regulations at 50 CFR 424.19.

Exclusions Based on National Security Impacts or Homeland Security
Impacts

Under section 4(b)(2) of the Act, we consider whether there are
lands owned or managed by the Department of Defense where a national
security impact might exist. Department of Homeland Security currently
owns 5 ac (2 ha) of land that is surrounded by land owned and managed
by BLM and lies within the proposed critical habitat boundary.
Specifically, these lands include a lighthouse facility that is managed
by the U.S. Coast Guard. The U.S. Coast Guard is in the process of
transferring ownership of these lands to BLM, and, therefore, we
anticipate no impact on national security from the inclusion of these
lands in the proposed critical habitat designation. Consequently, the
Secretary is not intending to exercise his discretion to exclude any
areas from the final designation based on impacts on national security.

Exclusions Based on Other Relevant Impacts

Under section 4(b)(2) of the Act, we consider any other relevant
impacts, in addition to economic impacts and impacts on national
security. We consider a number of factors including whether there are
permitted conservation plans covering the species in the area such as
HCPs, safe harbor agreements, or candidate conservation agreements with
assurances, or whether there are non-permitted conservation agreements
and partnerships that would be encouraged by designation of, or
exclusion from, critical habitat. In addition, we look at the existence
of tribal conservation plans and partnerships and consider the
government-to-government relationship of the United States with tribal
entities. We also consider any social impacts that might occur because
of the designation.
We are not considering any exclusions at this time from the
proposed critical habitat designation under section 4(b)(2) of the Act
based on partnerships, management, or protection afforded by
cooperative management efforts. Although there are no tribally owned
lands within the proposed designation, some areas within the proposed
critical habitat boundary include tribal trust resources under article
five of the Point Elliott treaty of 1855. The treaty of Point Elliott
states the following, ``The right of taking fish at usual and
accustomed grounds and stations is further secured to said Indians in
common with all citizens of the Territory, and of erecting temporary
houses for the purpose of curing, together with the privilege of
hunting and gathering roots and berries on open and unclaimed lands.''
We have initiated coordination with tribes regarding the proposed
critical habitat designation and will continue to offer government-to-
government consultation with them throughout development of the final
rulemaking. In this proposed rule, we are seeking input from the public
as to whether or not the Secretary should exclude any areas from the
final critical habitat designation. (Please see ADDRESSES, above, for
instructions on how to submit comments).
Private or Other Non-Federal Conservation Plans or Agreements and
Partnerships, in General
We sometimes exclude specific areas from critical habitat
designations based in part on the existence of private or other non-
Federal conservation plans or agreements and their attendant
partnerships. A conservation plan or agreement describes actions that
are designed to provide for the conservation needs of a species and its
habitat, and may include actions to reduce or mitigate negative effects
on the species caused by activities on or adjacent to the area covered
by the plan. Conservation plans or agreements can be developed by
private entities with no Service involvement, or in partnership with
the Service.
We evaluate a variety of factors to determine how the benefits of
any exclusion and the benefits of inclusion are affected by the
existence of private or other non-Federal conservation plans or
agreements and their attendant partnerships when we undertake a
discretionary 4(b)(2) exclusion analysis. A non-exhaustive list of
factors that we will consider for non-permitted plans or agreements is
shown below. These factors are not required elements of plans or
agreements, and all items may not apply to every plan or agreement.
(i) The degree to which the plan or agreement provides for the
conservation of the species or the essential physical or biological
features (if present) for the species;
(ii) Whether there is a reasonable expectation that the
conservation management strategies and actions contained in a
management plan or agreement will be implemented;
(iii) The demonstrated implementation and success of the chosen
conservation measures;
(iv) The degree to which the record of the plan supports a
conclusion that a critical habitat designation would impair the
realization of benefits expected from the plan, agreement, or
partnership;
(v) The extent of public participation in the development of the
conservation plan;
(vi) The degree to which there has been agency review and required
determinations (e.g., State regulatory requirements), as necessary and
appropriate;
(vii) Whether National Environmental Policy Act (NEPA; 42 U.S.C.
4321 et seq.) compliance was required; and
(viii) Whether the plan or agreement contains a monitoring program
and adaptive management to ensure that the conservation measures are
effective and can be modified in the future in response to new
information.
Private or Other Non-Federal Conservation Plans Related to Permits
Under Section 10 of the Act
HCPs for incidental take permits under section 10(a)(1)(B) of the
Act provide for partnerships with non-Federal entities to minimize and
mitigate impacts to listed species and their habitat. In some cases,
HCP permittees agree to do more for the conservation of the species and
their habitats on private lands than designation of critical habitat
would provide alone. We place great value on the partnerships that are
developed during the preparation and implementation of HCPs.
CCAAs and safe harbor agreements (SHAs) are voluntary agreements
designed to conserve candidate and listed species, respectively, on
non-Federal lands. In exchange for actions that contribute to the
conservation of species on non-Federal lands, participating property
owners are covered by an ``enhancement of survival'' permit under
section 10(a)(1)(A) of the Act, which authorizes incidental take of the
covered species that may result from implementation of conservation
actions, specific land uses, and, in the case of SHAs, the option to
return to a baseline condition under the agreements. The Service also
provides enrollees assurances that we will not impose further land-,
water-, or resource-use restrictions, or require additional commitments
of land, water, or finances, beyond those agreed to in the agreements.
When we undertake a discretionary 4(b)(2) exclusion analysis, we
will always consider areas covered by an approved CCAA/SHA/HCP, and
generally exclude such areas from a designation of critical habitat if
three conditions are met:

[[Page 15932]]

1. The permittee is properly implementing the CCAA/SHA/HCP, and is
expected to continue to do so for the term of the agreement. A CCAA/
SHA/HCP is properly implemented if the permittee is, and has been,
fully implementing the commitments and provisions in the CCAA/SHA/HCP,
implementing agreement, and permit.
2. The species for which critical habitat is being designated is a
covered species in the CCAA/SHA/HCP, or very similar in its habitat
requirements to a covered species. The recognition that the Services
extend to such an agreement depends on the degree to which the
conservation measures undertaken in the CCAA/SHA/HCP would also protect
the habitat features of the similar species.
3. The CCAA/SHA/HCP specifically addresses the habitat of the
species for which critical habitat is being designated and meets the
conservation needs of the species in the planning area.
There are currently no CCAA/SHA/HCPs in the area proposed for
designation, nor are we aware of any other non-federal conservation
plans in the area. However, should such plan(s) be developed prior to
publication of a final decision on critical habitat, we would consider
whether exclusion of the area covered by such plan(s) may be warranted
under section 4(b)(2) of the Act.

Required Determinations

Regulatory Planning and Review (Executive Orders 12866 and 13563)

Executive Order 12866 provides that the Office of Information and
Regulatory Affairs (OIRA) will review all significant rules. The Office
of Information and Regulatory Affairs has determined that this rule is
not significant.
Executive Order (E.O.) 13563 reaffirms the principles of E.O. 12866
while calling for improvements in the nation's regulatory system to
promote predictability, to reduce uncertainty, and to use the best,
most innovative, and least burdensome tools for achieving regulatory
ends. The executive order directs agencies to consider regulatory
approaches that reduce burdens and maintain flexibility and freedom of
choice for the public where these approaches are relevant, feasible,
and consistent with regulatory objectives. E.O. 13563 emphasizes
further that regulations must be based on the best available science
and that the rulemaking process must allow for public participation and
an open exchange of ideas. We have developed this rule in a manner
consistent with these requirements.

Executive Order 13771

This rule is not an E.O. 13771 (``Reducing Regulation and
Controlling Regulatory Costs'') (82 FR 9339, February 3, 2017)
regulatory action because this rule is not significant under E.O.
12866.

Regulatory Flexibility Act (5 U.S.C. 601 et seq.)

Under the Regulatory Flexibility Act (RFA; 5 U.S.C. 601 et seq.),
as amended by the Small Business Regulatory Enforcement Fairness Act of
1996 (SBREFA; 5 U.S.C. 801 et seq.), whenever an agency is required to
publish a notice of rulemaking for any proposed or final rule, it must
prepare and make available for public comment a regulatory flexibility
analysis that describes the effects of the rule on small entities
(i.e., small businesses, small organizations, and small government
jurisdictions). However, no regulatory flexibility analysis is required
if the head of the agency certifies the rule will not have a
significant economic impact on a substantial number of small entities.
The SBREFA amended the RFA to require Federal agencies to provide a
certification statement of the factual basis for certifying that the
rule will not have a significant economic impact on a substantial
number of small entities.
According to the Small Business Administration, small entities
include small organizations such as independent nonprofit
organizations; small governmental jurisdictions, including school
boards and city and town governments that serve fewer than 50,000
residents; and small businesses (13 CFR 121.201). Small businesses
include manufacturing and mining concerns with fewer than 500
employees, wholesale trade entities with fewer than 100 employees,
retail and service businesses with less than $5 million in annual
sales, general and heavy construction businesses with less than $27.5
million in annual business, special trade contractors doing less than
$11.5 million in annual business, and agricultural businesses with
annual sales less than $750,000. To determine if potential economic
impacts to these small entities are significant, we considered the
types of activities that might trigger regulatory impacts under this
designation as well as types of project modifications that may result.
In general, the term ``significant economic impact'' is meant to apply
to a typical small business firm's business operations.
The Service's current understanding of the requirements under the
RFA, as amended, and following recent court decisions, is that Federal
agencies are only required to evaluate the potential incremental
impacts of rulemaking on those entities directly regulated by the
rulemaking itself, and, therefore, not required to evaluate the
potential impacts to indirectly regulated entities. The regulatory
mechanism through which critical habitat protections are realized is
section 7 of the Act, which requires Federal agencies, in consultation
with the Service, to ensure that any action authorized, funded, or
carried out by the agency is not likely to destroy or adversely modify
critical habitat. Therefore, under section 7, only Federal action
agencies are directly subject to the specific regulatory requirement
(avoiding destruction and adverse modification) imposed by critical
habitat designation. Consequently, it is our position that only Federal
action agencies will be directly regulated by this designation. There
is no requirement under RFA to evaluate the potential impacts to
entities not directly regulated. Moreover, Federal agencies are not
small entities. Therefore, because no small entities are directly
regulated by this rulemaking, the Service certifies that, if
promulgated, the proposed critical habitat designation will not have a
significant economic impact on a substantial number of small entities.
In summary, we have considered whether the proposed designation
would result in a significant economic impact on a substantial number
of small entities. For the above reasons and based on currently
available information, we certify that, if promulgated, the proposed
critical habitat designation would not have a significant economic
impact on a substantial number of small business entities. Therefore,
an initial regulatory flexibility analysis is not required.

Energy Supply, Distribution, or Use--Executive Order 13211

Executive Order 13211 (Actions Concerning Regulations That
Significantly Affect Energy Supply, Distribution, or Use) requires
agencies to prepare Statements of Energy Effects when undertaking
certain actions. In our economic analysis, we did not find that the
designation of this proposed critical habitat would significantly
affect energy supplies, distribution, or use due to the absence of any
energy supply or distribution lines from the proposed critical habitat
designation. Therefore, this action is not a significant energy

[[Page 15933]]

action, and no Statement of Energy Effects is required.

Unfunded Mandates Reform Act (2 U.S.C. 1501 et seq.)

In accordance with the Unfunded Mandates Reform Act (2 U.S.C. 1501
et seq.), we make the following findings:
(1) This rule would not produce a Federal mandate. In general, a
Federal mandate is a provision in legislation, statute, or regulation
that would impose an enforceable duty upon State, local, or tribal
governments, or the private sector, and includes both ``Federal
intergovernmental mandates'' and ``Federal private sector mandates.''
These terms are defined in 2 U.S.C. 658(5)-(7). ``Federal
intergovernmental mandate'' includes a regulation that ``would impose
an enforceable duty upon State, local, or tribal governments'' with two
exceptions. It excludes ``a condition of Federal assistance.'' It also
excludes ``a duty arising from participation in a voluntary Federal
program,'' unless the regulation ``relates to a then-existing Federal
program under which $500,000,000 or more is provided annually to State,
local, and tribal governments under entitlement authority,'' if the
provision would ``increase the stringency of conditions of assistance''
or ``place caps upon, or otherwise decrease, the Federal Government's
responsibility to provide funding,'' and the State, local, or tribal
governments ``lack authority'' to adjust accordingly. At the time of
enactment, these entitlement programs were: Medicaid; Aid to Families
with Dependent Children work programs; Child Nutrition; Food Stamps;
Social Services Block Grants; Vocational Rehabilitation State Grants;
Foster Care, Adoption Assistance, and Independent Living; Family
Support Welfare Services; and Child Support Enforcement. ``Federal
private sector mandate'' includes a regulation that ``would impose an
enforceable duty upon the private sector, except (i) a condition of
Federal assistance or (ii) a duty arising from participation in a
voluntary Federal program.''
The designation of critical habitat does not impose a legally
binding duty on non-Federal Government entities or private parties.
Under the Act, the only regulatory effect is that Federal agencies must
ensure that their actions do not destroy or adversely modify critical
habitat under section 7. While non-Federal entities that receive
Federal funding, assistance, or permits, or that otherwise require
approval or authorization from a Federal agency for an action, may be
indirectly impacted by the designation of critical habitat, the legally
binding duty to avoid destruction or adverse modification of critical
habitat rests squarely on the Federal agency. Furthermore, to the
extent that non-Federal entities are indirectly impacted because they
receive Federal assistance or participate in a voluntary Federal aid
program, the Unfunded Mandates Reform Act would not apply, nor would
critical habitat shift the costs of the large entitlement programs
listed above onto State governments.
(2) We do not believe that this rule would significantly or
uniquely affect small governments because the area included in the
proposed critical habitat designation is largely owned by Federal and
State agencies (greater than 95 percent). None of these government
entities fits the definition of ``small government jurisdiction.''
Therefore, a Small Government Agency Plan is not required.

Takings--Executive Order 12630

In accordance with E.O. 12630 (Government Actions and Interference
with Constitutionally Protected Private Property Rights), we have
analyzed the potential takings implications of designating critical
habitat for the island marble butterfly in a takings implications
assessment. The Act does not authorize the Service to regulate private
actions on private lands or confiscate private property as a result of
critical habitat designation. Designation of critical habitat does not
affect land ownership, or establish any closures, or restrictions on
use of or access to the designated areas. Furthermore, the designation
of critical habitat does not affect landowner actions that do not
require Federal funding or permits, nor does it preclude development of
habitat conservation programs or issuance of incidental take permits to
permit actions that do require Federal funding or permits to go
forward. However, Federal agencies are prohibited from carrying out,
funding, or authorizing actions that would destroy or adversely modify
critical habitat. A takings implications assessment has been completed
and concludes that this proposed designation of critical habitat for
the island marble butterfly would not pose significant takings
implications for lands within or affected by the designation.

Federalism--Executive Order 13132

In accordance with E.O. 13132 (Federalism), this proposed rule does
not have significant Federalism effects. A federalism summary impact
statement is not required. In keeping with Department of the Interior
and Department of Commerce policy, we request information from, and
coordinated development of this proposed critical habitat designation
with, appropriate State resource agencies in Washington. From a
federalism perspective, the designation of critical habitat directly
affects only the responsibilities of Federal agencies. The Act imposes
no other duties with respect to critical habitat, either for States and
local governments, or for anyone else. As a result, the rule does not
have substantial direct effects either on the States, or on the
relationship between the national government and the States, or on the
distribution of powers and responsibilities among the various levels of
government. The designation may have some benefit to these governments
because the areas that contain the features essential to the
conservation of the species are more clearly defined, and the physical
or biological features of the habitat necessary to the conservation of
the species are specifically identified. This information does not
alter where and what federally sponsored activities may occur. However,
it may assist these local governments in long-range planning (because
these local governments no longer have to wait for case-by-case section
7 consultations to occur).
Where State and local governments require approval or authorization
from a Federal agency for actions that may affect critical habitat,
consultation under section 7(a)(2) would be required. While non-Federal
entities that receive Federal funding, assistance, or permits, or that
otherwise require approval or authorization from a Federal agency for
an action, may be indirectly impacted by the designation of critical
habitat, the legally binding duty to avoid destruction or adverse
modification of critical habitat rests squarely on the Federal agency.

Civil Justice Reform--Executive Order 12988

In accordance with Executive Order 12988 (Civil Justice Reform),
the Office of the Solicitor has determined that the rule does not
unduly burden the judicial system and that it meets the requirements of
sections 3(a) and 3(b)(2) of the Order. We have proposed designating
critical habitat in accordance with the provisions of the Act. To
assist the public in understanding the habitat needs of the species,
the proposed rule identifies the elements of physical or biological
features essential to the conservation of the species. The areas
proposed to be designated as critical habitat are presented on a map,
and the proposed

[[Page 15934]]

rule provides several options for the interested public to obtain more
detailed location information, if desired.

Paperwork Reduction Act of 1995 (44 U.S.C. 3501 et seq.)

This rule does not contain any new collections of information that
require approval by the Office of Management and Budget (OMB) under the
Paperwork Reduction Act of 1995 (44 U.S.C. 3501 et seq.). This rule
will not impose recordkeeping or reporting requirements on State or
local governments, individuals, businesses, or organizations. An agency
may not conduct or sponsor, and a person is not required to respond to,
a collection of information unless it displays a currently valid OMB
control number.

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).
It is also our position that, outside the jurisdiction of the U.S.
Court of Appeals for the Tenth Circuit, we do not need to prepare
environmental analyses pursuant to the National Environmental Policy
Act (NEPA; 42 U.S.C. 4321 et seq.) in connection with designating
critical habitat under the Act. This position was upheld by the U.S.
Court of Appeals for the Ninth Circuit (Douglas County v. Babbitt, 48
F.3d 1495 (9th Cir. 1995), cert. denied 516 U.S. 1042 (1996)).

Government-to-Government Relationship With Tribes

In accordance with the President's memorandum of April 29, 1994
(Government-to-Government Relations with Native American Tribal
Governments; 59 FR 22951), Executive Order 13175 (Consultation and
Coordination With Indian Tribal Governments), and the Department of the
Interior's manual at 512 DM 2, we readily acknowledge our
responsibility to communicate meaningfully with recognized Federal
Tribes on a government-to-government basis. In accordance with
Secretarial Order 3206 of June 5, 1997 (American Indian Tribal Rights,
Federal-Tribal Trust Responsibilities, and the Endangered Species Act),
we readily acknowledge our responsibilities to work directly with
tribes in developing programs for healthy ecosystems, to acknowledge
that tribal lands are not subject to the same controls as Federal
public lands, to remain sensitive to Indian culture, and to make
information available to tribes.
We determined that there are no tribally owned lands that are
occupied by the island marble butterfly at the time of listing that
contain the features essential for conservation of the species, and no
tribally owned lands unoccupied by the island marble butterfly that are
essential for the conservation of the species. While there are no
tribally owned lands within the proposed critical habitat designation,
some areas within the proposed critical habitat boundary may include
tribal trust resources under article five of the Point Elliott treaty
of 1855 (see Exclusions Based on Other Relevant Impacts, above, for
further information). We have sought government-to-government
consultation with these tribes during the development of this proposed
rule. We will consider these areas for exclusion from the final
critical habitat designation to the extent consistent with the
requirements of 4(b)(2) of the Act.

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.

References Cited

A complete list of references cited is available on the internet at
http://www.regulations.gov and upon request from the Washington Fish
and Wildlife Office (see FOR FURTHER INFORMATION CONTACT).

Authors

The primary authors of this proposed rule are the staff members of
the Washington 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--ENDANGERED AND THREATENED WILDLIFE AND PLANTS

0
1. The authority citation for part 17 continues to read as follows:

Authority: 16 U.S.C. 1361-1407; 1531-1544; and 4201-4245, unless
otherwise noted.

0
2. In Sec. 17.11(h), add an entry for ``Butterfly, island marble'' in
alphabetical order under ``INSECTS'' to the List of Endangered and
Threatened Wildlife to read as follows:

Sec. 17.11 Endangered and threatened wildlife.

* * * * *
(h) * * *

----------------------------------------------------------------------------------------------------------------
Listing
citations and
Common name Scientific name Where listed Status applicable
rules
----------------------------------------------------------------------------------------------------------------

* * * * * * *
----------------------------------------------------------------------------------------------------------------
Insects
----------------------------------------------------------------------------------------------------------------

[[Page 15935]]

* * * * * * *
Butterfly, island marble.... Euchloe Wherever found................ E............... [Federal
ausonides Register
insulanus. citation of
the final
rule]

* * * * * * *
----------------------------------------------------------------------------------------------------------------

* * * * *
0
3. In Sec. 17.95, amend paragraph (i) by adding an entry for ``Island
marble butterfly (Euchloe ausonides insulanus),'' in the same
alphabetical order that the species appears in the table at Sec.
17.11(h), to read as follows:

Sec. 17.95 Critical habitat--fish and wildlife.

* * * * *
(i) Insects.
* * * * *
Island marble butterfly (Euchloe ausonides insulanus)
(1) Critical habitat is depicted for San Juan County, Washington,
on the map below.
(2) Within the critical habitat area on San Juan Island,
Washington, the physical or biological features essential to the
conservation of the island marble butterfly consist of:
(i) Open, primarily treeless areas with short-statured forb- and
grass-dominated vegetation that include diverse topographic features
such as ridgelines, hills, and bluffs for patrolling, dispersal
corridors between habitat patches, and some south-facing terrain. Areas
must be large enough to allow for the development of patchy-population
dynamics, allowing for multiple small populations to establish within
the area.
(ii) Low- to medium-density larval host plants for egg-laying and
larval development, with both flower buds and blooms on them between
the months of May through July. Larval host plants may be any of the
following: Brassica rapa, Sisymbrium altissimum, or Lepidium
virginicum.
(iii) Adult nectar resources in flower and short-statured, white-
flowering plants in bloom used for mate-finding, which may include, but
are not limited to Abronia latifolia (yellow sand verbena), Achillea
millefolium (yarrow), Amsinckia menziesii (small-flowered fiddleneck),
Cakile edentula (American sea rocket), Cerastium arvense (field
chickweed), Erodium cicutarium (common stork's bill), Geranium molle
(dovefoot geranium), Hypochaeris radicata (hairy cat's ear), Lomatium
utriculatum (common lomatium), Lupinus littoralis (seashore lupine),
Myosotis discolor (common forget-me-not), Ranunculus californicus
(California buttercup), Rubus ursinus (trailing blackberry), Taraxacum
officinale (dandelion), Toxicoscordion venenosum (death camas, formerly
known as Zigadenus venenosus), and Triteleia grandiflora (Howell's
Brodiaea, formerly Brodiaea howellii).
(iv) Areas of undisturbed vegetation surrounding larval host plants
sufficient to provide secure sites for diapause and pupation. The
vegetation surrounding larval host plants must be left standing for a
sufficient period of time for the island marble butterfly to complete
its life cycle.
(3) Critical habitat does not include manmade structures (such as
buildings, aqueducts, runways, roads, and other paved areas) and the
land on which they are located existing within the legal boundaries on
the effective date of this rule.
(4) Critical habitat map unit. Data layers defining the map were
created using 2015 National Agriculture Imagery Program (NAIP) digital
imagery in ArcGIS, version 10.4 (Environmental Systems Research
Institute, Inc.), a computer geographic information system program. The
map in this entry, as modified by any accompanying regulatory text,
establishes the boundaries of the critical habitat designation. The
coordinates or plot points or both on which the map is based are
available to the public at the Service's internet site (https://www.fws.gov/wafwo/), at http://www.regulations.gov at Docket No. FWS-
R1-ES-2016-0145, and at the field office responsible for this
designation. You may obtain field office location information by
contacting one of the Service regional offices, the addresses of which
are listed at 50 CFR 2.2.
(5) Island marble butterfly critical habitat, San Juan County,
Washington.
(i) Island marble butterfly critical habitat consists of 812 acres
(ac) (329 hectares (ha)) on San Juan Island in San Juan County,
Washington, and is composed of lands in Federal (742 ac (301 ha)),
State (37 ac (15 ha)), State/County joint (1 ac (0.4 ha)), County (30
ac (12 ha)), and private (2 ac (0.8 ha)) ownership.
(ii) Map of island marble butterfly critical habitat follows:

[[Page 15936]]

[GRAPHIC] [TIFF OMITTED] TP12AP18.001

* * * * *

Dated: December 3, 2017.
James W. Kurth,
Deputy Director, U.S. Fish and Wildlife Service, Exercising the
Authority of the Director, U.S. Fish and Wildlife Service.

Editorial Note: The Office of the Federal Register received
this document on April 5, 2018.

[FR Doc. 2018-07347 Filed 4-11-18; 8:45 am]
BILLING CODE 4333-15-P