Federal Register, Volume 77 Issue 171 (Tuesday, September 4, 2012) 2012 Federal Register, 77 FR 54293-54329; Centralized Library: U.S. Fish and Wildlife Service -

[Federal Register Volume 77, Number 171 (Tuesday, September 4, 2012)]
[Proposed Rules]
[Pages 54293-54329]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2012-21243]

[[Page 54293]]

Vol. 77

Tuesday,

No. 171

September 4, 2012

Part III

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; 12-Month Finding on a
Petition To List Four Subspecies of Great Basin Butterflies as
Endangered or Threatened Species; Proposed Rule

Federal Register / Vol. 77 , No. 171 / Tuesday, September 4, 2012 /
Proposed Rules

[[Page 54294]]

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DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17

[Docket No. FWS-R8-ES-2012-0058; 4500030113]

Endangered and Threatened Wildlife and Plants; 12-Month Finding
on a Petition To List Four Subspecies of Great Basin Butterflies as
Endangered or Threatened Species

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Notice of 12-month petition finding.

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SUMMARY: We, the U.S. Fish and Wildlife Service (Service), announce a
12-month finding on a petition to list four subspecies of Great Basin
butterflies (White River Valley skipper (Hesperia uncas grandiosa),
Steptoe Valley crescentspot (Phyciodes cocyta arenacolor), Baking
Powder Flat blue butterfly (Euphilotes bernardino minuta), and bleached
sandhill skipper (Polites sabuleti sinemaculata)) in Nevada as
endangered or threatened species and designate critical habitat under
the Endangered Species Act of 1973, as amended (Act). After review of
the best available scientific and commercial information, we find that
listing these four butterfly and skipper subspecies is not warranted at
this time. However, we ask the public to submit to us any new
information that becomes available concerning the threats to the White
River Valley skipper, Steptoe Valley crescentspot, Baking Powder Flat
blue butterfly, and bleached sandhill skipper or their habitats at any
time.

DATES: The finding announced in this document was made on September 4,
2012.

ADDRESSES: This finding is available on the internet at http://www.regulations.gov at Docket Number FWS-R8-ES-2012-0058. The
supporting documentation we used in preparing this finding is available
for public inspection, by appointment, during normal business hours at
the U.S. Fish and Wildlife Service, Nevada Fish and Wildlife Office,
1340 Financial Boulevard, Suite 234, Reno, NV 89502. Please submit any
new information, materials, comments, or questions concerning this
finding to the above address.

FOR FURTHER INFORMATION CONTACT: Edward D. Koch, State Supervisor,
Nevada Fish and Wildlife Office (see ADDRESSES); by telephone (775-861-
6300), or by facsimile (775-861-6301). If you use a telecommunications
device for the deaf (TDD), please call the Federal Information Relay
Service (FIRS) at 800-877-8339.

SUPPLEMENTARY INFORMATION:

Background

Section 4(b)(3)(B) of the Act (16 U.S.C. 1531 et seq.), requires
that, for any petition to revise the Lists of Endangered and Threatened
Wildlife and Plants that contains substantial scientific or commercial
information that the listing may be warranted, we make a finding within
12 months of the date of the receipt of the petition. In this finding,
we will determine that the petitioned action is either: (1) Not
warranted, (2) warranted, or (3) warranted, but the immediate proposal
of a regulation implementing the petitioned action is precluded by
other pending proposals to determine whether species are an endangered
or threatened species, and expeditious progress is being made to add or
remove qualified species from the Lists of Endangered and Threatened
Wildlife and Plants. Section 4(b)(3)(C) of the Act requires that we
treat a petition for which the requested action is found to be
warranted but precluded as though resubmitted on the date of such
finding; that is, requiring a subsequent finding to be made within 12
months. We must publish these 12-month findings in the Federal
Register.

Previous Federal Actions

These four subspecies were included in our Category 2 candidate
list for November 21, 1991 (56 FR 58804). A Category 2 candidate
species was a species for which we had information indicating that a
proposal to list it as threatened or endangered under the Act may be
appropriate, but for which additional information on biological
vulnerability and threat was needed to support the preparation of a
proposed rule. Please see Table 1 to cross reference the names on the
1991 Category 2 candidate list with the names of the four subspecies
petitioned for listing.

Table 1--Four Great Basin, NV, butterflies: Previous and Current Common and Scientific Names
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Common name Scientific name
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Previous Current Previous Current
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White River Valley skipper........... White River Valley Hesperia uncas ssp..... Hesperia uncas
skipper. grandiosa
Steptoe Valley crescentspot.......... Steptoe Valley Phyciodes pascoensis Phyciodes cocyta
crescentspot. ssp. arenacolor
Baking Powder Flat blue butterfly.... Baking Powder Flat blue Euphilotes battoides Euphilotes bernardino
butterfly. ssp. minuta
Denio sandhill skipper............... Bleached sandhill Polites sabuleti Polites sabuleti
skipper. sinemaculata. sinemaculata
----------------------------------------------------------------------------------------------------------------

In the February 28, 1996, Candidate Notice of Review (CNOR) (61 FR
7595), we adopted a single category of candidate species defined as
follows: ``Those species for which the Service has on file sufficient
information on biological vulnerability and threat(s) to support
issuance of a proposed rule to list but issuance of the proposed rule
is precluded.'' In previous CNORs, species meeting this definition were
known as Category 1 candidates for listing. Thus, as of the 1996 CNOR,
the Service no longer considered Category 2 species as candidates,
including the four petitioned butterfly and skipper subspecies, and did
not include them in the 1996 candidate list or any subsequent CNORs.
The decision to no longer consider Category 2 species as candidates was
designed to reduce confusion about the status of these species and to
clarify that we no longer regarded these species as candidates for
listing.
On January 29, 2010, we received a petition dated January 25, 2010,
from WildEarth Guardians requesting that 10 subspecies of Great Basin
butterflies in Nevada and California be listed as endangered or
threatened species with critical habitat under the Act. The 10
subspecies of Great Basin butterflies are: White River Valley skipper,
Steptoe Valley crescentspot, Baking Powder Flat blue butterfly,
bleached sandhill skipper, Carson Valley silverspot (Speyeria nokomis
carsonensis), Carson Valley wood nymph (Cercyonis pegala carsonensis),
Mono Basin skipper (Hesperia uncas giulianii), Railroad Valley skipper
(Hesperia uncas fulvapalla), Railroad Valley skipper (Hesperia uncas
reeseorum), and Mattoni's blue butterfly (Euphilotes

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pallescens mattonii). In a March 26, 2010, letter to the petitioner, we
responded that we had reviewed the information presented in the
petition and determined that issuing an emergency regulation
temporarily listing the 10 subspecies as per section 4(b)(7) of the Act
was not warranted, although this was not requested in the petition. On
October 4, 2011, we made our 90-day finding that the petition did not
present substantial scientific or commercial information indicating
that listing 6 of the 10 subspecies (Carson Valley silverspot, Carson
Valley wood nymph, Mattoni's blue butterfly, Mono Basin skipper, and
the two Railroad Valley skipper subspecies) may be warranted (76 FR
61532). However, we determined that the petition presented substantial
scientific or commercial information indicating that listing of the
other four subspecies (White River Valley skipper, Steptoe Valley
crescentspot, Baking Powder Flat blue butterfly, and bleached sandhill
skipper) may be warranted, and we initiated a status review for these
subspecies. This notice constitutes the 12-month finding on the January
29, 2010, petition to list the White River Valley skipper, Steptoe
Valley crescentspot, Baking Powder Flat blue butterfly, and bleached
sandhill skipper as endangered or threatened species and designate
critical habitat under the Act.

Summary of Procedures for Determining the Listing Status of Species

Review of Status Based on Five Factors
Section 4 of the Act (16 U.S.C. 1533) and its implementing
regulations (50 CFR 424) set forth the procedures for adding a species
to, removing species from, or reclassifying species on the Federal
Lists of Endangered and Threatened Wildlife and Plants. Under section
4(a)(1) of the Act, a species may be determined to be an endangered or
threatened species based on 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.
In making this finding, information pertaining to the White River
Valley skipper, Steptoe Valley crescentspot, Baking Powder Flat blue
butterfly, and bleached sandhill skipper in relation to the five
factors provided in section 4(a)(1) of the Act is discussed below. 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. If there is exposure
and the species responds negatively, the factor may be a threat, and we
then attempt to determine how significant a threat it is. If the threat
is significant, it may drive or contribute to the risk of extinction of
the species such that the species may warrant listing as an endangered
or threatened species as those terms are defined by the Act. This does
not necessarily require empirical proof of a threat. The combination of
exposure and some corroborating evidence of how the species is likely
impacted could suffice. The mere identification of factors that could
impact a species negatively is not sufficient to compel a finding that
listing is appropriate; we require evidence that these factors are
operative threats that act on the species to the point that the species
may meet the definition of an endangered or threatened species under
the Act.

Evaluation of the Status of Each of the Four Butterfly and Skipper
Subspecies

For each of the four butterfly and skipper subspecies, we provide a
description of the subspecies and its habitat and biology, an
evaluation of listing factors for that subspecies, and our finding as
to whether the petitioned action is warranted or not for that
subspecies.
The four butterfly and skipper subspecies evaluated in this finding
are invertebrates endemic to the Great Basin region of Nevada. The four
subspecies are from the phylum Arthropoda, class Insecta, and order
Lepidoptera. Taxonomic families for the four subspecies are:
Hesperiidae, Nymphalidae, and Lycaenidae.
The petition provides information regarding the four subspecies'
rankings according to NatureServe, which considers the butterflies and
skippers at the subspecies taxonomic level and ranks each as
``critically imperiled'' or ``imperiled'' at the global, national, or
State level (WildEarth Guardians 2010, pp. 3-4). While the petition
states that these ``definitions of `critically imperiled' and
`imperiled' are at least equivalent to definitions of `endangered' or
`threatened' under the [Act],'' this is not an appropriate comparison.
According to its own Web site, NatureServe's assessment of any species
``does not constitute a recommendation by NatureServe for listing [that
species]'' under the Act (NatureServe 2008, p. 1). In addition,
NatureServe's assessment procedures include ``different criteria,
evidence requirements, purposes and taxonomic coverage [from those of]
government lists of endangered and threatened species, and therefore
these two types of lists should not be expected to coincide''
(NatureServe 2008, p. 1).

Species Information for the White River Valley Skipper

Taxonomy and Species Description

We accept the characterization of the White River Valley skipper
(Hesperia uncas grandiosa) as a valid subspecies based on its
description by Austin and McGuire (1998, p. 778). This subspecies is in
the Hesperiidae family (Austin 1998a, p. 838). Male wingspans range
from 0.63 to 0.7 inch (in) (16.0-17.6 millimeters (mm)). The upperside
of the wings are clay color. The forewing margin is blackish. The apex
has a large yellowish macule (spot, patch). The stigma (patch of scent
scales) is broad and black with a silver central line. The hindwing has
a black costa and narrow outer margin. The fringes of both wings are
pale gray. The underside of the forewing is paler than the upperside.
The apical macules are white. The area beneath the stigma and wing base
is black. The hindwing is olive-gray colored. The postmedian and sub-
basal macules are white. The veins are white medially and extend to the
outer margin (Austin and McGuire 1998, p. 778). Females range from 0.74
to 0.82 in (18.8-20.7 mm). The upperside of the wings is similar to
that of the males but is darker. The outer margin is broader than that
of the males. The apical macules are paler. The hindwing is blacker
than the male's hindwing. The fringes of both wings are very pale gray.
The underside of the wing is similar to that of the male, but it is
more blackish medially on the forewing. The hindwing postmedial macules
are larger and the white on the hindwing veins extend to the outer
margin usually (Austin and McGuire 1998, p. 778). Please refer to
Austin and McGuire (1998, p. 778) for a more detailed description of
this subspecies.

Distribution and Habitat

Descriptions of locations where the White River Valley skipper has
been found are rather vague. The White River Valley skipper's type
locality (location where the specimen from which a species is described
and named was collected) is a narrow marshy area in the

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White River channel, White River Valley, located 1 mile (mi) (1.6
kilometer (km)) north of the Nye County boundary in White Pine County,
Nevada (Austin and McGuire 1998, p. 778; Nevada Natural Heritage
Program (NNHP) 2010) (on private and Bureau of Land Management (BLM)
administered lands). This area is approximately 1.5 mi (2.4 km)
southwest of the Ruppes/Boghole area (White Pine County), where this
subspecies has also been observed on BLM and private lands (NNHP 2006,
p. 47). The subspecies is known from alkaline Distichlis spicata (salt
grass) flats in the White River Valley from Sunnyside (includes the
Flag Springs area) (Nye County) north to the type locality, a distance
of about 20 mi (32 km) (on unspecified BLM and private lands), and from
Big Smoky Valley at unspecified locations (northwestern Nye County)
(Austin and McGuire 1998, p. 778). This subspecies was also found at
Kirch Wildlife Management Area (WMA) (two areas at south ends of Tule
and Adams-McGill Reservoirs (on State lands) (Nye County) (Boyd, pers.
comm. 2012a, p. 2; b, p. 1) and at Moorman Springs (Nye County) (Boyd,
pers. comm. 2012b, p. 1) (on BLM and private lands).
A specimen that may be this subspecies was collected 1 mi (1.6 km)
south of Blind Spring, Spring Valley (White Pine County) (Austin and
McGuire 1998, p. 785). In 1998, Austin and McGuire (1998, pp. 778-779)
tentatively included populations from Spring Valley (based on one male
specimen) and Lake Valley (based on two male specimens with no site
specificity given) (Lincoln County), Nevada, within the range of this
subspecies. During a general terrestrial invertebrate survey conducted
in 2006 at 76 locations in eastern Nevada, a single male was
encountered east of Cleve Creek in Spring Valley (White Pine County)
(Ecological Sciences, Inc. 2007, p. 28) and was attributed to this
subspecies. This location is near other areas (not specified by
authors) where the subspecies has been previously documented, and is
not considered to be a significant range extension (Ecological
Sciences, Inc. 2007, p. 28). The size of each known occupied site or
the extent of this subspecies' host plant(s), or host plant abundance,
has not been reported.

Biology

The White River Valley skipper flies during June, July, and August
(Austin and McGuire 1998, p. 778; Austin et al., in litt. 2000, p. 4).
Though adult nectar sources have not been reported, it is possible that
they nectar on a variety of plants that are in flower during their
flight period. The apparent larval host plant is Juncus mexicanus
(Mexican rush) (Austin and Leary 2008, p. 11). This perennial plant
species occurs in moist habitats (Kartesz 1987, p. 1503; Reed 1988, pp.
8, 10; Austin and Leary 2008, p. 11). In Nevada, it is known from
western and southern counties, including Nye County (Kartesz 1987, p.
1503; http://www plants.usda.gov Web site accessed April 24, 2012). In
the western United States, in addition to Nevada, it occurs in Oregon,
California, Arizona, New Mexico, Colorado, and Texas (http://www
plants.usda.gov Web site accessed April 24, 2012).
There is little biological information available at the subspecies
level, but some inferences can be made from biological information from
related species at the species level. Information for the white-vein
skipper (Hesperia uncus) indicates eggs are pale greenish-white and are
laid singly on or near the host plant (Scott 1986, p. 435). Larvae eat
leaves, and they live in tied-leaf nests (Scott 1986, p. 435). Males
perch during the day on small hill tops seeking females (Scott 1986, p.
435).
The best available information does not include surveys documenting
this subspecies' population dynamics, nor its overall abundance, number
or size of populations, number of extirpated populations, if any, or
population trends.

Five-Factor Evaluation for the White River Valley Skipper

Information pertaining to the White River Valley skipper in
relation to the five factors provided in section 4(a)(1) of the Act is
discussed below.

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

Potential factors that may affect the habitat or range of the White
River Valley skipper are discussed in this section, including: (1)
Water development, (2) land development, (3) livestock grazing, (4)
nonnative plant invasion, (5) agriculture, (6) mining and energy
development, and (7) climate change.
Water Development
Riparian communities and associated springs, seeps, and small
streams comprise a small area of the Great Basin and Mojave Desert
regions, but provide habitat for 70 percent of the butterfly species in
these regions (Brussard and Austin 1993, cited in Brussard et al. 1998,
p. 508). The petition suggests that the historical range for the
petitioned butterfly and skipper subspecies has been reduced (WildEarth
Guardians 2010, p. 6), but specific supporting information is not
provided. Habitat associated with riparian and aquatic habitats,
including springs and seeps, has been reduced in Nevada due to various
purposes such as water diversions, development, livestock grazing,
recreation, mining, and power generation (Sada et al. 1992, p. 76; Noss
et al. 1995, p. 76; Brussard et al. 1998, pp. 531-532; Sada et al.
2001, pp. 11-16; Sada 2008, pp. 49-50). Commitments of water resources
beyond perennial yield may result in detrimental impacts to habitats in
a designated basin. Groundwater extraction that exceeds aquifer
recharge may result in surface water level decline, spring drying and
degradation, or the loss of aquatic habitat (Zektser et al. 2005, pp.
396-397).
The Nevada State Engineer (NSE) approves and permits groundwater
rights in Nevada and defines perennial yield as ``The amount of usable
water of a groundwater reservoir that can be withdrawn and consumed
economically each year for an indefinite period of time. It cannot
exceed the sum of the Natural Recharge, the Artificial (or Induced)
Recharge, and the Incidental Recharge without causing depletion of the
groundwater reservoir'' (Nevada Division of Water Planning (NDWP)
undated, p. 236). The NSE estimates perennial yield for 256 basins and
sub-basins (areas) in Nevada, and may ``designate'' a groundwater
basin, meaning the basin's ``* * * permitted ground water rights
approach or exceed the estimated average annual recharge and the water
resources are being depleted or require additional administration''
(NDWP undated, p. 81). In the interest of public welfare, the NSE may
declare preferred uses (such as municipal water supply, irrigation, or
minimum stream flows) within such basins (NDWP, undated, pp. 81-82).
Table 2 shows the perennial yield and committed groundwater rights for
selected basins in Nevada applicable to this finding (Southern Nevada
Water Authority (SNWA), in litt. 2011, p. 4).

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Table 2--Perennial Yield and Committed Groundwater Rights for Selected
Basins in Nevada (SNWA, in litt. 2011, p. 4)
------------------------------------------------------------------------
Committed
Perennial yield in groundwater rights
Hydrographic area acre-feet/year in acre-feet/year
(cubic meters/year) (cubic meters/year)
------------------------------------------------------------------------
Cave Valley................. 5,000-13,700 47-51 (57,974-
(6,167,409-16,898,7 62,908)
01).
Lake Valley................. 12,000 (14,801,782). 17,062 (21,045,667)
Spring Valley............... 80,000-94,800 21,702-22,507
(98,678,548-116,934 (26,769,023-27,761,
,080). 976)
Steptoe Valley.............. 70,000 (86,343,730). 114,144
(140,794,553)
White River Valley.......... 37,000 (45,638,829). 33,077 (40,799,879)
------------------------------------------------------------------------

The petition and others suggest that water development may impact
the White River Valley skipper (Austin et al., in litt. 2000, p. 4;
NatureServe 2009a, p. 2; WildEarth Guardians 2010, pp. 38-40). Lowering
of the groundwater table could impact the White River Valley skipper by
adversely impacting Juncus mexicanus, the apparent host plant for this
subspecies. This plant species grows in moist habitats such as wetlands
(Reed 1988, pp. 8, 10; Austin and Leary 2008, p. 11).
The NNHP estimates that approximately 50 percent of the springs and
brooks in both the upper White River (which includes Ruppes Place/
Boghole, where the subspecies has been located) and lower White River
(which includes Sunnyside, where the subspecies has been located) has
been eliminated, converted to other land uses, or degraded due to
various activities including water development (NNHP 2007, p. 44). The
NNHP estimates that approximately 60 percent of wetlands, springs, and
brooks in Big Smoky Valley (where the subspecies has been observed) has
been eliminated, converted to other land uses, or degraded by various
activities including water development (NNHP 2007, p. 35). However, the
NNHP (2007) does not delineate these areas on a map or define them in
terms of acreage; therefore, the amount of White River Valley skipper
habitat or the total number of occupied sites (made difficult because
locations where the skipper has been seen are not specific) that may
occur within these broad, vague areas and may be impacted by the
various activities are not documented. The extent to which the various
land use practices have degraded or converted these areas is also not
individually delineated or quantified by NNHP (2007). Therefore, we are
not able to determine the amount of overlap between the estimated
wetland impacts identified by the NNHP and the distribution of the
White River Valley skipper.
The White River Valley and Lake Valley hydrographic areas are
``designated'' basins by the NSE and permitted groundwater rights
approach or exceed the estimated average annual recharge of the basin
(Table 2; Nevada Department of Conservation and Natural Resources Web
site accessed at http://dcnr.nv.gov on May 15 and July 24, 2012). As a
``designated'' basin, the NSE has authority under NRS Sec. 534.120 to
establish additional rules, regulations, or orders to protect that
basin's water resources (SNWA, in litt. 2011, p. 41). If such
additional rules, regulations, or orders are established in the future,
they may also provide some protection to species dependent on these
water resources, such as the White River Valley skipper. The NSE can
declare preferred uses (such as domestic, municipal, industrial,
irrigation, or other uses) in a designated groundwater basin. To date,
neither the White River Valley nor Lake Valley hydrographic area has
preferred uses identified.
Specifically, the petition identifies the Southern Nevada Water
Authority (SNWA) proposed groundwater pumping project in central
eastern Nevada as a threat to the White River Valley skipper and other
butterflies (WildEarth Guardians 2010, p. 39). The following
information on the SNWA groundwater pumping project is also relevant to
and incorporated by this reference into the discussions of the Steptoe
Valley crescentspot and the Baking Powder Flat blue butterfly later in
this document.
The proposed Clark, Lincoln, and White Pine Counties Groundwater
Development Project Draft Environmental Impact Statement (EIS) (BLM
2011a) addresses SNWA's proposed project to construct and operate a
system of groundwater conveyance facilities, including pipelines,
pumping stations, power lines, a substation, pressure reduction
stations, an underground reservoir, a treatment plant, and associated
ancillary facilities to import up to 176,655 acre-feet/year (afy)
(217,900,737 cubic meters/year (m\3\y)) from central eastern Nevada
(Lincoln and White Pine Counties) to Las Vegas Valley (Clark County)
(BLM 2011a, pp. 1-2; Executive Summary (ES)-1).
Valleys that may be affected by the project's groundwater drawdowns
and that may also support three of the four petitioned subspecies,
including the White River Valley Skipper, are Cave Valley, Lake Valley,
Spring Valley, Steptoe Valley, and White River Valley. Currently, some
specific features of the proposed project are known (e.g., main
pipeline and associated facilities (power transmission, pump stations))
(BLM 2011a, p. 2-5). Locations of future facilities for groundwater
development including number and location of wells, routes and lengths
of collector pipelines, distribution lines, and access roads are not
yet known (BLM 2011a, p. 2-5). The impacts of future facility
development and groundwater withdrawal, which is analyzed conceptually
in BLM's draft EIS, will be specifically addressed in subsequent
National Environmental Policy Act (NEPA) analyses (BLM 2011a, p. 2-5).
This project is also contingent on the approval of SNWA's water
rights applications by the NSE (BLM 2011a, p. ES-14). On March 22,
2012, the NSE issued four rulings on SNWA's water right applications
for their proposed project totaling up to approximately 84,000 afy
(103,612,476 m\3\y) (Nevada Department of Conservation and Natural
Resources Web site accessed at http://dcnr.nv.gov on April 12, 2012);
this amount is a reduction from SNWA's recent request of approximately
105,000 afy (129,515,595 m\3\y). These four rulings are for Spring,
Cave, Dry Lake, and Delamar Valleys. Each of these applications is
subject to a minimum of 2 years of biological and hydrological data
collection prior to exportation; a hydrological monitoring, mitigation,
and management program; a biological monitoring plan, and a computer
groundwater flow model that must be updated to assist in predicting
impacts. If unanticipated impacts to existing water rights, conflicts
with existing domestic wells, or pumping is harmful to the public
interest or is not environmentally sound, SNWA would

[[Page 54298]]

be required to take measures to mitigate the impacts which could
include pumping curtailment. The proposed project's main pipeline is
scheduled for phased construction from 2013 to 2023 (BLM 2011a, pp. ES-
14-ES-15, ES-19). The entire project is scheduled to be constructed and
operational by approximately 2050 (BLM 2011a, p. 2-30).
Determining whether groundwater development is a threat to springs,
streams, or wetlands and therefore a potential threat to those
petitioned subspecies whose habitats are associated with moist areas
depends upon whether: (1) The basins in which withdrawals are occurring
or proposed exceed perennial yield or have a hydrologic connection to
springs and groundwater flow systems; (2) the springs, streams, or
wetlands are upgradient and outside of the zone of influence of the
carbonate aquifer (i.e., they occur in the alluvial aquifer or mountain
block aquifer instead); or (3) the springs, streams, or wetlands are
too far away from proposed pumping to be impacted (Welch et al. 2007,
pp. 71-79). Simply comparing permitted groundwater or surface water
rights to the perennial yield of a hydrographic area is inadequate to
determine if a site or biotic entity will be impacted as additional
factors should be considered as indicated above (SNWA, in litt. 2011,
p. 5). There needs to be hydraulic connectivity between groundwater
pumping and the site. If there is no hydraulic connectivity, a site
will not be impacted. A site may only be lightly impacted if the
distance is great or the transmissivity is low.
Hydraulic connectivity is influenced by hydrogeologic conditions
(groundwater flow systems, groundwater flow paths, flow direction, flow
barriers, etc.) (SNWA, in litt. 2011, p. 5). Comparing the amount of
permitted groundwater rights to a basin's estimated recharge or
perennial yield does not indicate that pumping exceeds the recharge or
that resources are being threatened (SNWA, in litt. 2011, p. 5). Permit
holders may not pump their entire amount due to self-imposed
restrictions, agreements, or permit requirements (SNWA, in litt. 2011,
p. 5). The manner and purpose of the water right use can also influence
potential impacts from groundwater or surface withdrawal (SNWA, in
litt. 2011, p. 6). A permit for agricultural use will not consume the
entire amount since a portion is returned to the groundwater system
through irrigation itself or through the inefficiency of the conveyance
system (SNWA, in litt. 2011, p. 6). Management of groundwater
development, monitoring, and conservation and mitigation measures can
reduce impacts of water withdrawal to a site and species (SNWA 2011, p.
6).
Groundwater flow modeling efforts for SNWA's proposed project are
described in BLM's draft EIS (BLM 2011a, pp. 3.3-80-3.3-85), as well as
the uncertainties and limitations expected with regional groundwater
flow models that cover a large area with complex hydrogeologic
conditions (BLM 2011a, pp. 3.3-85-3.3-87). While the model is a
reasonable tool for regional-scale drawdown trends (BLM 2011a, p. 3.3-
86), it is not an accurate predictor for site-specific changes in flow
for streams or springs (BLM 2011a, p. 3.3-87).
Two stipulations related to SNWA's proposed project were reached
between SNWA and four Department of the Interior bureaus (the Service,
the Bureau of Indian Affairs (BIA), the BLM, and the National Park
Service (NPS)) in 2006 and 2008 (SNWA, in litt. 2011, p. 8). The goals
of the Spring Valley Stipulation (BIA et al. 2006, p. 4) are to (1)
manage SNWA groundwater development in Spring Valley to avoid
unreasonable adverse effects to groundwater-influenced ecosystems
(e.g., springs) and maintain the biological integrity and ecological
health of the area of interest over the long-term, and (2) avoid
effects to groundwater-influenced ecosystems within the boundary of
Great Basin National Park. The goals of the Delamar Valley, Dry Lake
Valley, and Cave Valley (DDC) Stipulation (BIA et al. 2008, Exhibit A,
p. 2) are to manage the development of groundwater by SNWA in Delamar
Valley, Dry Lake Valley, and Cave Valley hydrographic areas without
causing (1) injury to Federal water rights and (2) any unreasonable
adverse effects to Federal resources and special status species within
the area of interest as a result of groundwater withdrawals in those
basins by SNWA; and (3) to take actions that protect and recover
special status species that are currently listed pursuant to the Act
and that avoid listing of currently non-listed special-status species.
Both stipulations have a list of requirements related to management,
creation of technical and management teams, a consensus-based
decisionmaking process, and monitoring and mitigation which, if the
SNWA project is constructed, will benefit and avoid and minimize
threats relevant to the White River Valley skipper, Steptoe Valley
crescentspot, and the Baking Powder Flat blue butterfly (SNWA, in litt.
2011, pp. 8-10).
In addition to the two stipulations, an Adaptive Management Plan
has been prepared by SNWA for its proposed project. It includes a list
of measures that can be implemented based on the environmental resource
impacted, the severity, and likely cause(s) (BLM 2011a, Appendix E,
Appendix A, pp. A-46-A-57). The Adaptive Management Plan acknowledges
the uncertainties in predicting effects of groundwater withdrawal on
hydrologic flow systems. The plan will identify and implement
practicable adaptive management measures to address adverse
environmental impacts relevant to the three butterfly and skipper
subspecies including avoiding, minimizing, or mitigating: (1) Adverse
environmental impacts to groundwater-dependent ecosystems and their
biological communities, (2) effects of actions that could contribute to
listing of species under the Act, and (3) adverse environmental impacts
to water features that support fish and wildlife species. Specific
actions to be implemented would be determined at a later date based on
data collection and monitoring results.
The proposed project construction and operation may impact White
River Valley skipper habitat (BLM 2011a, p. 3.6-27). The White River
Valley skipper was not detected in the project's ROW surveys of
groundwater development areas (BLM 2011a, pp. 3.6-18-3.6-19; 3.6-94).
Based on the groundwater flow model estimate for 200 years post full
buildout, the skipper's occupied areas at Ruppes Place/Boghole (SNWA,
in litt. 2011, p. 17) and areas at the Flag Springs Complex/Sunnyside/
Kirch Wildlife Management Area (SNWA, in litt. 2011, p. 19) are located
outside of the greater than 10-foot (3.0-m) drawdown contour (or any
other contour range) (BLM 2011a, p. 3.3-102). However, based on the
model estimate, there is a potential 17 percent flow decrease at 200-
years post full buildout at Flag Springs 3 (BLM 2011a, p. 3.3-108). The
Flag Springs Complex and Sunnyside Creek are biological monitoring
sites under the DDC Stipulation and are hydrologic monitoring sites
under the Hydrologic Monitoring and Mitigation Plan for Delamar, Dry
Lake, and Cave Valleys (Exhibit A of the DDC Stipulation (BIA et al.
2008,)) (SNWA, in litt. 2011, p. 19), which would be monitored for
early signs of impacts to these areas with mitigating measures
available to reduce adverse impacts to the area and thus to the White
River Valley skipper. While the Service recognizes that uncertainties
remain regarding potential impacts to water resources, all but one
location occupied by White River Valley skipper

[[Page 54299]]

occur outside of the estimated drawdown contour in the White River
Valley.
Based on the groundwater flow model estimate for 200 years post
full buildout (BLM 2011a, p. 3.3-102), an unknown portion of this
skipper's occupied habitat is located within the greater than 10-foot
(3.0-m) drawdown contour and could be impacted at Blind Spring in
Spring Valley. Because its apparent larval host plant, Juncus
mexicanus, is a wetland species, habitat for the White River Valley
skipper could be affected by the SNWA water development project (BLM
2011a, p. 3.6-74). Though monitoring is occurring using surface-water
gages, groundwater monitoring wells, and a piezometer on or near Cleve
Creek (Spring Valley), possible future project impacts to White River
Valley skipper in Spring Valley are unclear (SNWA, in litt. 2011, p.
20). As indicated earlier, there is uncertainty whether the White River
Valley skipper is actually found in Spring Valley (Austin and McGuire
1998, pp. 778-779).
Based on the recent water right application rulings issued by the
NSE for reduced pumping amounts in Spring Valley (Nevada Department of
Conservation and Natural Resources Web site accessed at http://dcnr.nv.gov on April 12, 2012), it appears that potential impacts at
Blind Spring would be reduced. Additionally, these recent rulings
require that the pumping in Spring Valley occur in stages with an
initial pumping of 38,000 afy (46,872,311.0 m\3\y) for 8 years and the
full amount of approximately 61,000 afy (75,242,393.2 m\3\y) being
pumped only if previous stages indicate it is appropriate based on data
collection and management plans indicated above (biological and
hydrological data collection; hydrological monitoring, mitigation, and
management program; biological monitoring plan, and a computer
groundwater flow model) (Nevada Department of Conservation and Natural
Resources Web site accessed at http://dcnr.nv.gov on April 12, 2012).
Lake Valley is also shown to be impacted by pumping (BLM 2011a, p.
3.3-102; SNWA, in litt. 2011, pp. 20-21), but as described in the
Distribution and Habitat section, there is uncertainty whether the
White River Valley skipper occurs in Lake Valley (Austin and McGuire
1998, pp. 778-779). Without specific locations indicated for specimens
collected in Lake Valley, it is difficult to determine possible impacts
to this subspecies from SNWA's proposed project in this valley. We
conclude that SNWA's proposed groundwater development project would not
impact populations of this subspecies in Big Smoky Valley as these
populations occur too far west of the proposed project area and occur
outside of the area(s) that would be affected by the groundwater
project.
While human water demands have impacted wetland areas in the White
River and Big Smoky Valleys, the White River Valley skipper is rather
widespread throughout its known distribution in these valleys. Other
locations (Spring Valley and Lake Valley) where the subspecies may be
found are tentative locations based on Austin and McGuire (1998, pp.
778-779). The possible host plant for the White River Valley skipper,
Juncus mexicanus, has not been confirmed as the host plant at any
location where the skipper has been observed (Austin and Leary 2008, p.
11). Because of these uncertainties related to some of the subspecies'
reported locations as well as its host plant, overall potential impacts
due to SNWA's proposed project are difficult to determine. However,
based on the possible impact to only one occupied White River Valley
skipper location (Flag Springs 3), the recent water right application
rulings issued by the NSE for reduced pumping amounts in Spring Valley
and the presumed reduction in potential impacts at Blind Spring as well
as the initial staged pumping in Spring Valley (Nevada Department of
Conservation and Natural Resources Web site accessed at http://dcnr.nv.gov on April 12, 2012), we do not anticipate major impacts to
the White River Valley skipper from SNWA's proposed project.
In addition, the SNWA water project has multiple design features
developed to reduce adverse effects to groundwater-influenced
ecosystems. The Spring Valley Stipulation (BIA et al. 2006, Exhibit A,
p. 10), which was negotiated between SNWA, the Service, BIA, BLM, and
the NPS, requires an adaptive management approach in implementation of
the water development project, monitoring, mitigation (may include
geographic redistribution, reduction, or cessations in groundwater
withdrawals; provision of consumptive water supply requirements using
surface and groundwater sources; augmentation of water supply for
Federal water rights and resources using surface and groundwater
sources; and other measures agreed to by the parties or the NSE
consistent with the stipulation), creation of technical and management
teams, and a consensus-based decisionmaking process. These project
design features will likely result in reduced potential effects of the
project on habitat suitability for the White River Valley skipper.
While water development has occurred in parts of the White River
Valley skipper's range (White River Valley and Big Smoky Valley), we
found no information indicating effects from past water development
have resulted in loss or degradation of White River Valley skipper
habitat. The SNWA water project could affect groundwater flow in
certain parts of the White River Valley skipper's known and possible
range (White River Valley, Spring Valley, and Lake Valley), but not in
other parts of its range (Big Smoky Valley). The SNWA water project
also has multiple design features developed to reduce adverse effects
to groundwater-influenced ecosystems. At this time, the best available
information does not indicate that water development is modifying the
White River Valley skipper's habitat to the extent that it represents a
threat to this subspecies now or in the future.
Land Development
Different levels of development can greatly alter the amount of
larval host plants and adult nectar sources for butterflies, affecting
directly the distribution and abundance of individual species and
indirectly the microclimate (Blair and Launer 1997, p. 119). Blair and
Launer (1997, p. 116) found the abundance of the 23 butterfly species
included in their California study varied across the development
gradient from natural to urban. The butterfly community contained fewer
species in more developed sites compared to the relatively undeveloped
oak-woodland community (Blair and Launer 1997, p. 117). Species
richness and diversity was greatest at moderately disturbed sites while
the relative abundance decreased from the natural to the urban areas
(Blair and Launer 1997, p. 113).
Bock et al. (2007, pp. 40-41) found that low-density housing
developments in former ranch lands of Arizona impacted butterfly
species abundance and variety to a lesser degree than in developed
urban or suburban landscapes as documented elsewhere by others.
Summerville and Crist (2001) studied the effects of habitat
fragmentation on patch use by butterflies and skippers. They found that
butterflies and skippers select habitat based on quantity (size) and
quality (flower availability); moderately-sized patches of high quality
may function equally to larger patches of lower quality (Summerville
and Crist 2001, p. 1367). Species did not respond

[[Page 54300]]

equally to fragmentation, with rare species no longer using patches
where less than 40 percent of the habitat remained (Summerville and
Crist 2001, p. 1365). While some common species appeared unaffected by
fragmentation, other common species were significantly affected
(Summerville and Crist 2001, p. 1365).
The petition suggests that land development may impact this
subspecies (WildEarth Guardians 2010, pp. 38-40). A portion of the
springs and wetlands in the upper and lower White River and Big Smoky
Valleys have been eliminated, converted, or degraded due to land uses,
such as land development (NNHP 2007, pp. 35, 44). The NNHP (2007) does
not delineate these areas in terms of location, acreage, or by land use
practice. Although the White River Valley skipper is known to occur in
several locations within these valleys, the number of sites or the
amount of White River Valley skipper habitat that may be impacted by
land development is not documented.
The best available information does not indicate that land
development is occurring in habitat that is occupied by the White River
Valley skipper. We did not receive any information as a result of our
90-day petition finding notice, nor did we locate information
indicating that land development is negatively impacting the habitat or
the known populations of the White River Valley skipper. Therefore, the
best available information does not indicate that land development is
modifying the subspecies' habitat to the extent that it represents a
threat to this subspecies now or in the future.
Livestock Grazing
Potential impacts of livestock grazing include selective grazing
for native plant species and reducing cover, trampling of plants and
soil, damage to soil crusts, reduction of mycorrhizal fungi, increases
in soil nitrogen, increases in erosion and runoff, increases in fire
frequency, and contribution to nonnative plant introductions (Fleishner
1994, pp. 631-635; Belsky et al. 1999, pp. 8-11; Paige and Ritter 1999,
pp. 7-8; Belsky and Gelbard 2000, pp. 12-18; Sada et al. 2001, p. 15).
In relation to butterflies, as noted in the petition, livestock
grazing can impact host plants as well as nectar sources, trample
larvae and the host or nectar plants, degrade habitats, and assist in
the spread of nonnative plant species that can dominate or replace
native plant communities and thereby impact larval host and adult
nectar species (WildEarth Guardians 2010, pp. 22-23). While the
petition states that light or moderate grazing can assist in
maintaining butterfly habitats (WildEarth Guardians 2010, p. 23), heavy
grazing is considered incompatible with the conservation of some
butterflies (Sanford 2006, p. 401; Selby 2007, pp. 3, 29, 33, 35).
Kruess and Tscharntke (2002, p. 1570) found an increase of species
richness and abundance from pastures to ungrazed grasslands in Germany
for grasshoppers, butterflies, bees, and wasps. Decreased grazing on
pastures resulted in increased species richness and abundance for adult
butterflies. Vogel et al. (2007, p. 78) evaluated three restoration
practices in prairie habitat in Iowa on butterfly communities and found
that the total butterfly abundance was highest in areas restored
through burning and grazing, and was lowest in areas that were only
burned. Species richness did not differ among the practices. Species
diversity was highest in areas that were only burned. Individual
butterfly species responses to the restoration practices were variable.
BLM regulatory authority for grazing management is provided at 43
CFR part 4100 (Regulations on Grazing Administration Exclusive of
Alaska). Livestock grazing permits and leases contain terms and
conditions determined by BLM to be appropriate to achieve management
and resource condition objectives on the public lands and other lands
administered by the BLM, and to ensure that habitats are, or are making
significant progress toward, being restored or maintained for BLM
special status species (43 CFR 4180.1(d)). Grazing practices and
activities include the development of grazing-related portions of
implementation or activity plans, establishment of terms and conditions
of permits, leases, and other grazing authorizations, and range
improvement activities such as vegetation manipulation, fence
construction, and development of water for livestock.
BLM grazing administration standards for a particular state or
region must address habitat for endangered, threatened, proposed,
candidate, or special status species, and habitat quality for native
plant and animal populations and communities (43 CFR 4180.2(d)(4) and
(5)). The guidelines must address restoring, maintaining, or enhancing
habitats of BLM special status species to promote their conservation,
and maintaining or promoting the physical and biological conditions to
sustain native populations and communities (43 CFR 4180.2(e)(9) and
(10)).
The petition and others suggest that livestock grazing may impact
this subspecies (NatureServe 2009a, p. 2; WildEarth Guardians 2010, pp.
38-40), but specific information supporting this claim is not provided.
A portion of the springs and wetlands in the upper and lower White
River and Big Smoky Valleys have been eliminated, converted, or
degraded due to other land uses, such as livestock grazing (NNHP 2007,
pp. 35, 44). The NNHP (2007) does not delineate these areas in terms of
location, acreage, or by land use practice. The type locality (1 mi
(1.6 km) north of the Nye County line) is on private and BLM lands. It
is not known how livestock grazing is managed on the private lands, but
general knowledge of the area indicates it is not heavily grazed during
the late spring to early summer period (Lowrie in litt. 2012, p. 1).
The Ruppes/Boghole location is on private and BLM lands. It is not
known how grazing is managed on the private lands, but the area has
been grazed in the past (Lowrie in litt. 2012, p. 7), and the site
appears to continue to provide suitable habitat for the skipper (Lowrie
in litt. 2012, p. 7).
The type locality and the Ruppes/Boghole sites are surrounded by
three BLM grazing allotments (Dee Gee Spring to the east, North Cove to
the west; and Swamp Cedar to the northwest) (Lowrie in litt. 2012, p.
1), which may support limited suitable habitat (Lowrie in litt. 2012,
pp. 5-6). The allotments are permitted for cattle grazing during the
late winter to early summer, though none are grazed the entire period
(Lowrie in litt. 2012, pp. 1-3). The animal unit months have generally
been reduced since 1999 for all three allotments; each allotment has
received growing season rest in various years since 1999 (Lowrie in
litt. 2012, pp. 3-5).
The Kirch WMA encompasses about 14,800 ac (5,989 ha) of public
State lands with five major reservoirs (www.NDOW.org, p. 6; accessed
April 27, 2012). Based on observations in 2005 when the White River
Valley skipper was observed on the WMA, Boyd (pers. comm. 2012b, p. 1)
thought grazing by feral horses may have occurred at the south end of
Tule Reservoir. The area is primarily a recreational area with limited
fishing, hunting, camping, and OHV use during certain times.
The presumed larval host plant, Juncus mexicanus, is common and can
be found in several Nevada counties in moist habitats. The adults
likely feed on a variety of plants flowering during their flight
period. The best available information does not indicate declines in
larval or adult plant species in

[[Page 54301]]

occupied White River Valley skipper habitat due to livestock grazing.
Activities involving grazing management within any suitable White River
Valley skipper habitat on BLM lands are addressed in consideration of
the Ely District Record of Decision and Approved Resource Management
Plan (RMP) (BLM 2008a) (see Factor D discussion under White River
Valley skipper), BLM's authority under Regulations on Grazing
Administration Exclusive of Alaska, BLM's 6840 Manual (BLM 2008b) (see
Factor D discussion under White River Valley skipper), and possibly
NEPA.
We did not receive any additional information as a result of our
90-day petition finding notice, nor did we locate information
indicating that livestock grazing is negatively impacting the habitat
or White River Valley skipper populations. Thus, the best available
information does not indicate that livestock grazing is modifying the
subspecies' habitat to the extent that it represents a threat to this
subspecies now or in the future.
Nonnative Plant Invasion
Nonnative species can present a range of threats to native
ecosystems, including extinction of native species, alteration of
ecosystem functions, and introduction of infectious diseases
(Schlaepfer et al. 2011, p. 429). However, not all nonnative species
cause economic or biological harm and only a small percentage become
established and result in harmful effects (Williamson and Fitter 1996
and Davis 2009, cited in Schlaepfer et al. 2011, p. 429). Nonnative
species can provide a conservation value, for example, by providing
food or habitat for rare species (Schlaepfer et al. 2011, p. 431).
The introduction of nonnative or invasive plant species or types of
vegetation (forbs, shrubs, grasses, etc.) can threaten butterfly
populations because these introduced species may compete with and
decrease the quantity and quality of larval host plants and adult
nectar sources (76 FR 12667, March 8, 2011). This competition resulting
in loss of host plants and nectar sources has been observed with the
Quino checkerspot butterfly (Euphydryas editha quino) (62 FR 2313,
January 16, 1997) and Fender's blue butterfly (Icaricia icarioides
fenderi) (65 FR 3875, January 25, 2000). However, Graves and Shapiro
(2003, p. 430) found that California butterflies use numerous nonnative
plant species positively and negatively. Some of them are using these
nonnative plant species for depositing eggs and feeding, which has led
to range expansions, increased population size, extension of the
breeding season as well as the opportunity to remain in an area where
the native host plant species has been lost. Nonnative plant species
have also allowed butterfly species from outside the State to invade
and breed in California. There are also instances where egg laying has
occurred on a nonnative plant species that is toxic to the larvae.
There has been an increased focus on the roles that State, county,
and private entities have in controlling invasive plants. For example,
the Noxious Weed Control and Eradication Act of 2004 is intended to
assist eligible weed management entities to control or eradicate
harmful nonnative weeds on both public and private lands and is an
amendment to the Plant Protection Act of 2000 (1 U.S.C. 7701 et seq.,
p. 1) which, in part, determined that detection, control, eradication,
suppression, prevention, and retardation of the spread of noxious weeds
is necessary to protect the agriculture, environment, and economy in
the United States. Additionally, Executive Order 13112 was signed on
February 3, 1999, establishing an interagency National Invasive Species
Council in charge of creating and implementing a National Invasive
Species Management Plan. The Management Plan directs Federal efforts,
including overall strategy and objectives, to prevent, control, and
minimize invasive species and their impacts (National Invasive Species
Council 2008, p. 5). However, the Executive Order also directs the
Council to encourage planning and action at local, tribal, state,
regional, and ecosystem levels to achieve the goals of the National
Invasive Species Management Plan, in cooperation with stakeholders
(e.g., private landowners, states) and existing organizations
addressing invasive species.
Noxious and invasive weed treatments on BLM lands involving
reseeding can occur through the Emergency Stabilization and Burned Area
Rehabilitation Program, a program available to BLM districts (including
Ely and Winnemucca Districts) which evaluates conditions following
wildland fire. Actions can be taken to protect soils, riparian areas,
cultural resources, as well as to reduce potential invasive plant
species spread. Invasive plant species control is a management
objective stated in many RMPs, including the RMPs for Ely and
Winnemucca Districts.
BLM commonly uses herbicides on lands to control invasive plant
species. In 2007, BLM completed a programmatic EIS (BLM 2007a) and
Record of Decision (BLM 2007b) for vegetation treatments on BLM-
administered lands in the western United States. This program approves
the use of 4 new herbicides, provides updated analyses of 18 currently
used herbicides, and identifies herbicides that the BLM will no longer
use on public lands. Information is unavailable on how frequently the
programmatic EIS has been used for most states or whether actions
implemented under this EIS have been effective; and while not
authorizing any specific on-the-ground actions, it guides the use of
herbicides for field-level planning. Site-specific NEPA analysis is
still required at the project level (BLM 2007a, pp. ES-1- ES-2).
A portion of the springs and wetlands in the upper and lower White
River and Big Smoky Valleys has been eliminated, converted, or degraded
due to other land uses, such as nonnative species invasion (NNHP 2007,
pp. 35, 44). It is likely nonnative and invasive plant species occur to
some extent because numerous nonnative and invasive plant species occur
in Nevada, though this has not been quantified within the habitat of
the White River Valley skipper. The White River Valley skipper is
possibly associated with Juncus mexicanus as its larval host plant
which is common in the White River Valley and other moist habitats in
Nevada. Nonnative plant species do not appear to be competing with
Juncus mexicanus, causing its decline or the decline of potential adult
nectar plants.
Activities involving nonnative plant species management within the
White River Valley skipper habitat on BLM lands would be addressed in
consideration of the Ely District Record of Decision and Approved RMP
(BLM 2008a), BLM's authority under Regulations on Grazing
Administration Exclusive of Alaska, the Plant Protection Act of 2000,
BLM's programmatic EIS for vegetation treatments on BLM's administered
lands in the western United States (BLM 2007a), BLM's 6840 Manual (BLM
2008b), and possibly NEPA (see Factor D). Activities involving
nonnative plant species management and control on private lands within
the White River Valley habitat could also be addressed in consideration
of the Plant Protection Act of 2000. We did not receive any information
as a result of the 90-day petition finding notice, nor did we locate
information indicating that nonnative plant species in general, or that
a specific nonnative or invasive plant species, actually occur in and
are negatively impacting the habitat and

[[Page 54302]]

populations of the White River Valley skipper. Consequently, the best
available information does not indicate that nonnative plant species
are modifying the subspecies' habitat to the extent that it represents
a threat to this subspecies now or in the future.
Agriculture
Agricultural practices can eliminate suitable habitat, resulting in
losses of butterfly species. Fleishman et al. (1999, pp. 214-215)
states that artificial riparian areas such as irrigated croplands
support fewer butterfly species than native habitats; that most
butterfly species found in agricultural sites are widespread
generalists often found in disturbed sites; that less common species,
as well as those restricted in native larval host plants, are less
likely to or do not occur in agricultural sites, and though agriculture
can provide habitat for some butterfly species, these modified habitats
cannot replace the natural undisturbed riparian ecosystems.
The petition and others suggest that the White River Valley skipper
may be impacted by agriculture (NatureServe 2009a, p. 2; WildEarth
Guardians 2010, pp. 38-40), though specific information is not provided
to support this claim. A portion of the springs and wetlands in the
upper and lower White River and Big Smoky Valleys has been eliminated,
converted, or degraded due to other land uses, including agriculture
(NNHP 2007, pp. 35, 44). The best available information does not
indicate that agriculture is occurring in areas that are occupied by
the White River Valley skipper. We did not receive any information as a
result of the 90-day petition finding notice, nor did we locate
information that indicates agriculture is negatively impacting the
White River Valley skipper populations, host plants, or nectar sources.
Thus, the best available information does not indicate that agriculture
is modifying the subspecies' habitat to the extent that it represents a
threat to this subspecies now or in the future.
Mining and Energy Development
Possible impacts to butterflies due to mining exploration and
development, renewable and nonrenewable energy exploration and
development, as well as associated power line installation include loss
of habitat, habitat fragmentation, increased dispersal barriers,
increases in predators, and disturbance due to human presence.
The Federal Land Policy and Management Act of 1976 (FLPMA) (43
U.S.C. 1701 et seq.) is the primary Federal law governing most land
uses on BLM administered lands. Section 102(a)(8) of FLPMA specifically
recognizes that wildlife and fish resources are included as uses for
which these lands are to be managed. BLM has management and permitting
authorities to regulate and condition oil and gas lease permits under
FLPMA and the Mineral Leasing Act of 1920, as amended (30 U.S.C. 181 et
seq.). BLM usually incorporates stipulations as a condition of issuing
leases. The BLM's planning handbook has program-specific guidance for
fluid materials (including oil and gas) that specifies that RMP
decision-makers will consider restrictions on areas subject to leasing,
including closures, and lease stipulations (BLM 2000, Appendix C, p.
16). The handbook also specifies that all stipulations must have
waiver, exception, or modification criteria documented in the plan, and
indicates that the least restrictive constraint to meet the resource
protection objective should be used (BLM 2000, Appendix C, p. 16).
There are specific, major power line installation projects in
eastern Nevada. The Southwest Intertie Project, proposed by Idaho Power
Company, involves installation of an approximately 520-mi (836.7-km)
500-kilovolt (kV) transmission line from Shoshone, Idaho, to Las Vegas,
Nevada (BLM 1993, p. 1; 2008c, p. 1). Though the White River Valley
skipper is known from the project area, impacts to it from this project
were not identified (BLM 1993, pp. 3-75-3-89). The Record of Decision
approving this action was published in 2008 (BLM 2008c). The One Nevada
Transmission Line Project, proposed by NV Energy, involves construction
of a 236-mile (252.3-km) 500-kV transmission line with
telecommunication and appurtenant facilities, construction and
expansion of substations, and a loop in the existing Falcon-Gonder
transmission line in White Pine, Nye, Lincoln, and Clark Counties (BLM
2010c, p. ES-2). The White River Valley skipper was not observed during
wildlife surveys conducted for this project (BLM 2010c, Appendix 3D,
Table 2, pp. 1-5). A Record of Decision approving this project was
published in 2011 (BLM 2011b).
A Programmatic EIS for the Designation of Energy Corridors on
Federal Land in the 11 Western States was published in 2008 (Department
of Energy (DOE) and BLM 2008). This EIS addresses section 368 of the
Energy Policy Act of 2005, which directs the designation of corridors
for oil, gas, and hydrogen pipelines, and electricity transmission and
distribution facilities on Federal lands. Federal agencies are required
to conduct environmental reviews to complete the designation and
incorporate the designated corridors into agency land use and RMPs or
equivalent plans. This EIS proposes only designation of corridors, and
no environmental impacts are attributed to this action. Section 368
does not require agencies to consider or approve specific projects,
applications for ROW, or other permits within any designated corridor,
nor does section 368 direct, license, or permit any activity on the
ground. Any interested applicant would need to apply for a ROW
authorization, and the agency would consider each application under the
requirements of various laws and related regulations (DOE and BLM 2008,
pp. S-1-S-2). The proposed action would designate more than 6,000 mi
(9,600 km) with an average width of 3,500 ft (1 km) of energy corridors
across the West (DOE and BLM 2008, p. S-17). Federal land not presently
in transportation or utility rights-of-way is proposed for use in
Nevada (373 mi or 600 km) (DOE and BLM 2008, p. S-18). The Record of
Decision for this action was published in 2009 (BLM 2009b). BLM RMPs
will be amended as appropriate to address these issues (BLM 2009b, pp.
31-34).
The White River Valley skipper may be impacted by mining and energy
development according to the petition (WildEarth Guardians 2010, p.
39), though specific information is not provided to support this claim.
The NNHP indicates that a portion of the springs and wetlands in the
upper and lower White River and Big Smoky Valleys have been eliminated,
converted, or degraded due to other land uses, including mining and
energy development, but these areas were not delineated (NNHP 2007, pp.
35, 44). Actions involving mineral and energy development within White
River Valley skipper habitat on BLM-administered lands would be
addressed in consideration of the Ely District Record of Decision and
Approved RMP (BLM 2008a), the FLPM A of 1976, the Mineral Leasing Act
of 1920, BLM's 6840 Manual (BLM 2008b), and NEPA. The best available
information does not indicate that mining and energy development are
occurring in occupied White River Valley skipper habitat. We did not
receive any information as a result of the 90-day petition finding
notice, nor did we locate information that indicates mining or energy
development is negatively impacting the subspecies' habitat or White
River Valley skipper populations. Thus, the best available information
does not

[[Page 54303]]

indicate that mining and energy development are modifying the
subspecies' habitat to an extent that they represent a threat to this
subspecies now or in the future.
Climate Change
The effects on species and ecosystems due to climate change are
numerous. For example, there are direct effects due to different
temperatures on the physiology of an organism (McCarty 2001, p. 321).
Precipitation amounts directly affect vegetation distribution (McCarty
2001, p. 321). Climate can also have indirect effects on species
through the sensitivity of habitats or food supply to temperature and
precipitation (McCarty 2001, p. 321).
Climate change is expected to affect the timing and flow of
streams, springs, and seeps in the Great Basin (Chambers 2008a, p. 20),
which support the moist meadows upon which some butterflies depend
(WildEarth Guardians 2010, p. 9). Earlier spring snowmelt appears to be
affecting the date of blooming for some plants in the Great Basin
(Chambers 2008b, p. 29). As stated in the petition, potential changes
in the bloom date of meadow plants due to climate change could affect
the use of these plants by butterflies (WildEarth Guardians 2010, p.
9). Drought in the Great Basin could negatively affect riparian
habitats, moist meadows, and similar habitats, especially those already
stressed by other factors (Major 1963 cited by West 1983, p. 344). As
climate changes, droughts may become more common in the Great Basin
(Chambers et al. 2008, p. 3) and American Southwest (Seager et al.
2007, pp. 1181-1183), modifying future precipitation (WildEarth
Guardians 2010, p. 8). Increased carbon dioxide may favor invasion of
annual grasses such as the nonnative Bromus tectorum (cheatgrass)
(Smith et al. 2000, pp. 79, 81). Increased temperatures and carbon
dioxide levels have various effects on plant growth and chemistry,
which may affect insect abundance and persistence (Stiling 2003, pp.
486-488). Increasing temperatures can also affect insect development
and reproduction (Sehnal et al. 2003, pp. 1117-1118).
The rate at which a species can adapt and change its boundaries may
be vital to understanding how species will respond to climate change
(McCarty 2001, p. 327). Studies of groups of species show most are
responding to climate change; what is also important is to study those
that do not seem to be responding (McCarty 2001, pp. 327-328). These
species may be less sensitive to temperature, or they may be unable to
respond to current moderate increases in temperature (McCarty 2001, p.
328).
According to Loarie et al. (2009, p. 1052), species and ecosystems
will need to shift northward an average of 0.3 mi (0.42 km) per year to
avoid the effects of increasing temperatures associated with climate
change. Loarie et al. (2009, p. 1053) also state that distances may be
greater for species in deserts and xeric (dry habitat) shrublands,
where climate change is predicted to have greater effect than in some
other ecosystems. The petition asserts that it is unlikely that small,
isolated populations of butterflies in the Great Basin, dependent on
reduced habitats, will be able to shift to other habitats in the face
of climate change (WildEarth Guardians 2010, p. 9). Many species in the
Great Basin have specialized habitat requirements and limited mobility,
which influence their ability to adapt to anthropogenic environmental
change (Fleishman 2008, p. 61). The petition states that species and
habitats already stressed by other factors may be less able to cope
with climate change (WildEarth Guardians 2010, p. 10).
Certain butterflies have shown an ability to adjust to changing
climatic conditions. Parmesan (2006, p. 643) reported that butterflies
frequently show a correlation between spring temperatures and dates of
first appearance. According to Forister and Shapiro (2003 cited in
Parmesan 2006, p. 643), 70 percent of 23 species of central California
butterflies advanced their first flight date by an average of 24 days
over 31 years. Parmesan (1996, pp. 765-766) showed a range shift for
Edith's checkerspot butterfly (Euphydryas edithia); this butterfly's
``population extinctions'' occurred in relation to both latitude and
elevation showing a shift of extant population locations northward and
upward.
The average temperature in the Great Basin has increased 0.6-1.1
degrees Fahrenheit (0.3-0.6 degrees Celsius) during the last 100 years
(Chambers 2008b, p. 29) and is expected to increase by 3.6-9.0 degrees
Fahrenheit (2-5 degrees Celsius) over the next century (Cubashi et al.
2001, cited Chambers 2008b, p. 29).
Recent projections of climate change in the Great Basin over the
next century include: Increased temperatures, with an increased
frequency of extremely hot days in summer; more variable weather
patterns and more severe storms; more winter precipitation in the form
of rain, with potentially little change or decreases in summer
precipitation; and earlier, more rapid snowmelt (U.S. Environmental
Protection Agency 1998, pp. 1-4; Chambers and Pellant 2008, pp. 29-33).
While the petition asserts that climate change may impact this
subspecies (WildEarth Guardians 2010, pp. 38-40), it is difficult to
predict local climate change impacts, due to substantial uncertainty in
trends of hydrological variables, limitations in spatial and temporal
coverage of monitoring networks, and differences in the spatial scales
of global climate models and hydrological models (Bates et al. 2008, p.
3).
We found no information on how climate change may impact the White
River Valley skipper's potential host plant, Juncus mexicanus, or adult
nectar sources. In general, increasing temperatures and drought
frequency, more winter precipitation in the form of rain, possible
decreases in summer rain, and earlier, rapid snowmelt could impact the
host plant by causing physiological stress, altering phenology,
reducing recruitment events, and reducing seed establishment. However,
at this time, it is difficult to predict local climate change impacts
to Juncus mexicanus or to White River Valley skipper's adult nectar
sources, and how individual plant species will react to climate change.
Thus, while information indicates that climate change has the potential
to affect vegetation and habitats used by the White River Valley
skipper in the Great Basin, there is much uncertainty regarding which
habitat attributes could be affected, and the timing, magnitude, and
rate of their change as it relates to this subspecies.
We did not receive any information as a result of our 90-day
petition finding notice, nor did we locate specific information that
indicates climate change is negatively impacting White River Valley
skipper populations or their habitats. Therefore, the best available
information does not indicate that climate change is modifying the
subspecies' habitat to an extent that it represents a threat to this
subspecies now or in the future.
Summary of Factor A
While several activities such as water and land development,
livestock grazing, nonnative species invasion, agriculture, and mining
and energy development may be impacting a portion of wetland areas in
White River and Big Smoky Valleys, available information does not
indicate that these impacts are occurring in occupied White River
Valley skipper habitat. The available information does not indicate
that these activities or climate change are negatively impacting White
River Valley skipper populations. Since the White River Valley skipper
may be associated with wetland areas, impacts

[[Page 54304]]

from water development could impact the subspecies; however, all but
one occupied skipper locations are outside the greater than 10-foot
(3.0-m) drawdown contour for the SNWA proposed project, and major
impacts are not anticipated for this subspecies in White River Valley.
Other locations in Spring and Lake Valleys that may support the
subspecies are located within the greater than 10-foot (3.0-m) drawdown
contour for the SNWA proposed project but potential impacts from
groundwater pumping would be reduced due to the recent NSE rulings.
While information indicates that climate change has the potential to
affect vegetation used by this subspecies, much uncertainty remains
regarding which plant attributes may be affected, and the timing,
magnitude, and rate of their change.
We conclude based on the best scientific and commercial information
available that the present or threatened destruction, modification, or
curtailment of its habitat or range does not currently pose a threat to
the White River Valley skipper, nor is it likely to become a threat to
the subspecies in the future.

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

Rare butterflies and moths are prized by collectors, and an
international trade exists for insect specimens for both live and
decorative markets, as well as the specialist trade that supplies
hobbyists, collectors, and researchers (Morris et al. 1991, pp. 332-
333; Williams 1996, pp. 30-37). The specialist trade differs from both
the live and decorative market in that it concentrates on rare and
threatened species (U.S. Department of Justice 1993, pp. 2-3). In
general, the rarer the species, the more valuable it is (Morris et al.
1991, p. 333).
Collecting can be a threat to some butterfly species, such as the
Fender's blue butterfly (65 FR 3875). Generally, small populations are
at the highest risk. Overcollecting and repeated handling and marking
of females for scientific purposes in low abundance years can
negatively impact populations through loss of reproductive individuals
and genetic variability (65 FR 3875). Collection of dispersing females
can also reduce the probability that new colonies will be founded.
Collectors may serve as a threat because they may not recognize when
butterfly populations are becoming depleted below a threshold necessary
for survival or recovery (65 FR 3875).
We are unaware of any studies analyzing impacts of removal of
individuals from populations of the White River Valley skipper.
According to Austin and McGuire (1998, p. 778), 20 males and 14 females
were collected between 1984 and 1989 at one site. No additional
information is known about the numbers of specimens collected in the
past, and we are not aware of any ongoing or current collecting of this
subspecies. Given the low number of individuals collected over this 6-
year period, the length of time since the collections were made, and
the lack of information about the relative impact to the populations,
the available information does not indicate that collection may be a
threat to this subspecies.
We found no information indicating that overutilization has led to
the loss of populations or a significant reduction in numbers of
individuals for this subspecies. Therefore, we conclude based on the
best scientific and commercial information available that
overutilization for commercial, recreational, scientific, or
educational purposes does not currently pose a threat to the White
River Valley skipper, nor is it likely to become a threat in the
future.

Factor C. Disease or Predation

We found no information on the incidence of disease in the White
River Valley skipper.
We assume predation by other species, such as birds or insects, on
eggs, larvae, pupae, or adult White River Valley skipper occurs, but we
found no information indicating that predation levels are any greater
than levels typical of the biological community in which the White
River Valley skipper occurs.
Available information does not indicate that there are impacts from
disease or predation on the White River Valley skipper. Therefore, we
conclude based on the best scientific and commercial information
available that disease or predation does not currently pose a threat to
the White River Valley skipper, nor is either likely to become a threat
to the subspecies in the future.

Factor D. The Inadequacy of Existing Regulatory Mechanisms

This discussion under Factor D applies to all four subspecies and
is incorporated by this reference into the Factor D discussion for
Steptoe Valley crescentspot, Baking Powder Flat blue butterfly, and
bleached sandhill skipper.
Nevada does not have the ability to protect invertebrates under
current State law pertaining to wildlife. The Nevada Department of
Wildlife is limited in its ability to protect insects under current
regulations (Nevada Revised Statutes (NRS)). Nevada State law protects
species that the Wildlife Commission determines to be imperiled (NRS
503.585). While some invertebrates such as mollusks and crustaceans may
be protected because they can be classified under wildlife (NRS
501.110), butterflies are not covered under this statute. No butterfly
or skipper species are currently protected by State law in Nevada
(Nevada Administrative Code 503.020-503.080). Therefore, no regulatory
protection is offered under Nevada State law for the White River Valley
skipper, Steptoe Valley crescentspot, Baking Powder Flat blue
butterfly, or bleached sandhill skipper. Although not protected by
State law, the best available information, as discussed in Factor B,
does not indicate that collection or other forms of overutilization is
a threat to the White River Valley skipper.
As discussed earlier under Factor A, the NSE approves and permits
groundwater rights in Nevada. A basin's perennial yield is considered
during this process, and the NSE may ``designate'' a groundwater basin
indicating that the water resources in that basin are being depleted or
require additional administration. The White River Valley and the Lake
Valley hydrographic areas are ``designated'' basins, and the NSE has
authority to establish additional rules, regulations, or orders to
protect the basin's water resources. These additional rules,
regulations, or orders, if established in the future, may provide some
protection to species dependent on these water resources, such as the
White River Valley skipper. The best available information does not
indicate that water development is impacting White River Valley skipper
populations.
As discussed above, a portion of habitat for the White River Valley
skipper occurs on lands administered by BLM, a Federal land-management
agency within the U.S. Department of the Interior. Numerous laws,
regulations, and policies have been developed to assist the agency in
management of these lands.
All Federal agencies are required to adhere to NEPA for projects
they fund, authorize, or carry out. The Council on Environmental
Quality's regulations for implementing NEPA (40 CFR 1500-1518) state
that agencies shall include a discussion on the environmental impacts
of the various project alternatives, any adverse environmental effects
which cannot be avoided, and any irreversible or irretrievable
commitments of resources involved (40 CFR 1502). Additionally,
activities on non-Federal lands are subject to NEPA

[[Page 54305]]

if there is a Federal nexus. NEPA is a disclosure law and does not
require subsequent minimization or mitigation measures by the Federal
agency involved. Although Federal agencies may include conservation
measures for sensitive species as a result of the NEPA process, any
such measures are typically voluntary in nature and are not required by
the statute.
BLM's RMPs are the basis for all actions and authorizations
involving BLM-administered land and resources. They establish allowable
resource uses; resource conditions, goals, and objectives to be
attained; program constraints and general management practices needed
to attain the goals and objectives; general implementation sequences;
and intervals and standards for monitoring and evaluating each plan to
determine its effectiveness and the need for amendment or revision (43
CFR 1601.0-5(k)).
RMPs provide a framework and programmatic guidance for site-
specific activity plans. These plans address livestock grazing, oil and
gas field development, travel management (managing vehicle routes and
access), wildlife habitat management, and other activities. Actions
potentially affecting the White River Valley skipper, as well as the
Steptoe Valley skipper and Baking Powder Flat blue butterfly, would be
addressed under the Ely District Record of Decision and Approved RMP
(BLM 2008a); actions potentially affecting the bleached sandhill
skipper would be addressed under the Winnemucca District RMP and EIS
(BLM 2010a). Activity plan decisions normally also require NEPA (42
U.S.C. 4321 et seq.) analysis.
BLM policy and guidance for species of concern occurring on BLM-
administered land is addressed under BLM's 6840 Manual ``Special Status
Species Management'' (BLM 2008b). This manual provides agency policy
and guidance for the conservation of special status plants and animals
and the ecosystems on which they depend, but it is not a regulatory
document. The objectives for BLM special status species are ``to
conserve and/or recover ESA-listed species and the ecosystems on which
they depend so that ESA protections are no longer needed for these
species and to initiate proactive conservation measures that reduce or
eliminate threats to Bureau sensitive species to minimize the
likelihood of and need for listing of these species under the ESA.''
(BLM 2008b, p. 3). All four of the butterfly and skipper subspecies
addressed in this finding are designated BLM sensitive species (BLM
2007a, pp. J-6, J-7, J-37).
BLM also operates under its Regulations on Grazing Administration
Exclusive of Alaska, codified at 43 CFR part 4100, which include
requirements that grazing administration standards address habitat for
special status species and habitat quality for native plant and animal
populations and communities (43 CFR 4180.2(d)(4) and (5)) that
livestock grazing permits and leases contain terms and conditions
determined by BLM to be appropriate to achieve management and resource
condition objectives on the public lands. See discussion under
Livestock Grazing, above.
These BLM policies and guidance address species of concern, actions
covered by RMPs, and regulatory authority for grazing and oil and gas
leasing and operating activities. As discussed under Factor A, the best
available information does not indicate that activities, such as
livestock grazing, nonnative species control, and mining and energy
development that are regulated by various policies, guidance, and laws
on Federal lands, are impacting White River Valley skipper populations.
We conclude based on the best scientific and commercial information
available that the inadequacy of existing regulatory mechanisms does
not currently pose a threat to the White River Valley skipper, nor is
it likely to become a threat to the subspecies in the future.

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

Potential other natural or manmade factors that may affect the
continued existence of the White River Valley skipper are discussed in
this section and include: (1) Limited range and (2) small population
size(s).
A limited range or small population size(s) can be a threat for
some species that may increase the likelihood of extinction.
Characteristic butterfly population fluctuations and short generation
times, combined with small populations, can influence genetic diversity
and long-term persistence (Britten et al. 2003, pp. 229, 233). Concern
may arise for butterflies that occur as single populations or in a few
disjunct populations, and the number of populations may be more
important than population size when assessing the status of a butterfly
(Sanford 2006, p. 401). Lack of dispersal corridors or resistance to
barriers to dispersal may inhibit gene flow between populations, and
increase the likelihood of extinction (Wilcox and Murphy 1985, pp. 882-
883). The combination of few populations, small ranges, and restricted
habitats can make a species susceptible to extinction or extirpation
from portions of its range due to random events such as fire, drought,
disease, or other occurrences (Shaffer 1987, pp. 71-74; Meffe and
Carroll 1994, pp. 190-197).
Limited range and small population numbers or sizes are considered
in determining whether a natural or anthropogenic threat, or a
combination of threats, may be affecting a particular subspecies.
However, in the absence of information identifying chance events, other
threats, the potential for such chance events to occur in occupied
habitats, and connecting these threats to a restricted geographic range
of a subspecies, we generally do not consider chance events, restricted
geographic range, or rarity by themselves to be threats to a
subspecies. In addition, butterfly populations are highly dynamic and
from year to year butterfly distributions can be highly variable (Weiss
et al. 1997, p. 2); and desert species seem prone to dramatic
fluctuations in number (Scott 1986, p. 109).
As indicated earlier, the White River Valley skipper is known from
the White River Valley in White Pine and Nye Counties and from Big
Smoky Valley in Nye County. It may also occupy areas in Spring and Lake
Valleys in White Pine and Lake Valley Counties, respectively. The
aerial extent of each occupied site or of the subspecies' apparent host
plant has not been reported. Little information is available related to
its distribution and numbers of populations, and no information is
available related to population sizes, loss of populations, if any, or
population trends for the White River Valley skipper. The best
available information does not include comprehensive surveys for this
subspecies, though researchers have recommended these surveys to
determine if additional populations exist.
Without data to indicate population trends, it is difficult to
support claims of adverse impacts to the White River Valley skipper. We
found no information on connections between chance events and
population impacts for the White River Valley skipper. Since this
subspecies is distributed over several populations, potential impacts
due to stochastic events may be reduced. In the absence of chance
events connected to known populations, we do not consider small
population numbers or restricted range by themselves to be threats to
this subspecies. The best available information does not indicate the
White River Valley skipper is negatively

[[Page 54306]]

impacted by limited range or small population numbers. We conclude
based on the best scientific and commercial information available that
other natural or manmade factors do not currently pose a threat to the
White River Valley skipper, nor are they likely to become a threat to
the subspecies in the future.

Synergistic Interactions Between Threat Factors

We have evaluated individual threats to the White River Valley
skipper. This subspecies faces potential threats from water
development, land development, livestock grazing, nonnative plant
invasion, agriculture, mining and energy development, climate change,
limited range, and small population size. In considering whether the
threats to a species may be so great as to warrant listing under the
Act, we must look beyond the possible impacts of potential threats in
isolation and consider the potential cumulative impacts of all of the
threats facing a species.
In making this finding, we considered whether there may be
cumulative effects to the White River Valley skipper from the combined
impacts of the existing stressors such that even if each stressor
individually does not result in population-level impacts, that
cumulatively the effects may be significant. We considered whether the
combined effects of water development, land development, and mining and
energy development may result in a significant impact to the White
River Valley skipper because these potential impacts have the potential
to result in some level of habitat loss. However, we conclude that
synergistic effects between water development, land development, and
mining and energy development are unlikely to result in a significant
overall population impact to the White River Valley skipper because the
water development activities have been ongoing in the valleys and the
proposed water development project is not anticipated to cause major
impacts because only one known occupied White River Valley skipper
location may be impacted to some unknown extent. Impacts from land
development and mining and energy development were not found to be
occurring in the subspecies' habitat.
While livestock grazing and nonnative plant invasion could impact
the White River Valley skipper and its habitat, livestock grazing and
nonnative plant species invasion are not known to be resulting in
population declines of either host plants or nectar plants in occupied
locations. We conclude that livestock grazing and nonnative plant
species invasion combined with potential impacts from water development
would not be of sufficient severity, frequency, or geographic scope to
result in significant habitat impacts or cause population-level impacts
to the White River Valley skipper. Agriculture was not found to occur
within this subspecies' habitat, and therefore, will not have a
cumulative impact on the White River Valley skipper.
Limited range and small population size could make the White River
Valley skipper more vulnerable to potential threats discussed above.
However, we cannot conclude that synergistic effects between limited
range and small population size and other potential threats are
operative threats to the continued existence of the White River Valley
skipper given the lack of information on the range and population size
of this butterfly. There is no information on population size or change
in population abundance for the White River Valley skipper, and the
limited information on occurrence (distribution) is insufficient to
define this skipper's range.
Synergistic interactions are possible between effects of climate
change and effects of other potential threats such as water
development, livestock grazing, and nonnative plant invasion. Increases
in carbon dioxide and temperature and changes in precipitation are
likely to affect vegetation, and the White River Valley skipper is
closely associated with the presence of vegetation. However, it is
difficult to project how climate change will affect vegetation because
certain plant species may increase in cover while other species may
decrease. Uncertainty about how different plant species will respond
under climate change, combined with uncertainty about how changes in
plant species composition would affect suitability of White River
Valley skipper habitat, make projecting possible synergistic effects of
climate change on the White River Valley skipper too speculative.

Finding for the White River Valley Skipper

As required by the Act, we considered the five factors in assessing
whether the White River Valley skipper is an endangered or threatened
species throughout all of its range. We examined the best scientific
and commercial information available regarding the past, present, and
future threats faced by this subspecies.
Factors potentially affecting the White River Valley skipper,
including water development, land development, livestock grazing,
nonnative species invasion, agriculture, mining and energy development,
or climate change, and limited range and small population size, are
either limited in scope or lack documentation that they are occurring
in occupied habitat and adversely impacting the subspecies. Though
climate change may be affecting the White River Valley skipper and its
habitats, and effects are likely to increase in the future, available
information does not support a determination that climate change has or
will result in a population-level impact to this subspecies. Available
information does not indicate that overutilization, disease, or
predation are threats to the White River Valley skipper. The available
information also does not indicate that existing regulatory mechanisms
are inadequate to protect the subspecies from potential threats.
Furthermore, there is no information to suggest that the combined
factors acting together are a threat to the White River Valley skipper.
Based on our review of the best scientific and commercial information
available, we find these potential stressors, either singly or in
combination with one another, are not threats to the White River Valley
skipper or its habitat.
We found no information to indicate that threats are of sufficient
imminence, intensity, or magnitude such that the White River Valley
skipper is in danger of extinction (endangered) or likely to become
endangered within the foreseeable future (threatened), throughout all
of its range. Therefore, we find that listing the White River Valley
skipper as an endangered or threatened species is not warranted
throughout its range.

Significant Portion of the Range

Having determined that the White River Valley skipper does not meet
the definition of an endangered or a threatened species, we must next
consider whether there are any significant portions of the range where
the White River Valley skipper is in danger of extinction or is likely
to become endangered in the foreseeable future. The Act defines
``endangered species'' as any species which is ``in danger of
extinction throughout all or a significant portion of its range,'' and
``threatened species'' as any species which is ``likely to become an
endangered species within the foreseeable future throughout all or a
significant portion of its range.'' 16 U.S.C. 1532(6) and 1532(20). The
definition of ``species'' is also relevant to this discussion. The Act
defines ``species'' as follows: ``The term `species' includes any
subspecies of fish

[[Page 54307]]

or wildlife or plants, and any distinct population segment of any
species of vertebrate fish or wildlife which interbreeds when mature.''
16 U.S.C. 1532(16). The phrase ``significant portion of its range''
(SPR) is not defined by the statute, and we have never addressed in our
regulations: (1) The consequences of a determination that a species is
either endangered or likely to become so throughout a significant
portion of its range, but not throughout all of its range; or (2) what
qualifies a portion of a range as ``significant.''
Two recent district court decisions have addressed whether the SPR
language allows the Service to list or protect less than all members of
a defined ``species'': Defenders of Wildlife v. Salazar, 729 F. Supp.
2d 1207 (D. Mont. 2010), concerning the Service's delisting of the
Northern Rocky Mountains gray wolf (74 FR 15123, April 2, 2009); and
WildEarth Guardians v. Salazar, 2010 U.S. Dist. LEXIS 105253 (D. Ariz.
September 30, 2010), concerning the Service's 2008 finding on a
petition to list the Gunnison's prairie dog (73 FR 6660, February 5,
2008). The Service had asserted in both of these determinations that,
under the Act, it had authority, in effect, to protect only some
members of a ``species,'' as defined by the Act (i.e., species,
subspecies, or DPS). Both courts ruled that the determinations were
arbitrary and capricious on the grounds that this approach violated the
plain and unambiguous language of the Act. The courts concluded that
reading the SPR language to allow protecting only a portion of a
species' range is inconsistent with the Act's definition of
``species.'' The courts concluded that once a determination is made
that a species (i.e., species, subspecies, or DPS) meets the definition
of ``endangered species'' or ``threatened species,'' it must be placed
on the list in its entirety and the Act's protections applied
consistently to all members of that species throughout its range
(subject to modification of protections through special rules under
sections 4(d) and 10(j) of the Act).
Consistent with that interpretation, and for the purposes of this
finding, we interpret the phrase ``significant portion of its range''
in the Act's definitions of ``endangered species'' and ``threatened
species'' to provide an independent basis for listing. Thus there are
two situations (or factual bases) under which a species would qualify
for listing: A species may be endangered or threatened throughout all
of its range, or a species may be endangered or threatened in only a
significant portion of its range. If a species is in danger of
extinction throughout an SPR, it, the species, is an ``endangered
species.'' The same analysis applies to ``threatened species.'' Based
on this interpretation and supported by existing case law, the
consequence of finding that a species is endangered or threatened in
only a significant portion of its range is that the entire species
shall be listed as endangered or threatened, respectively, and the
Act's protections shall be applied across the species' entire range.
We conclude, for the purposes of this finding, that interpreting
the SPR phrase as providing an independent basis for listing is the
best interpretation of the Act because it is consistent with the
purposes and the plain meaning of the key definitions of the Act; it
does not conflict with established past agency practice (i.e., prior to
the 2007 Solicitor's Opinion), as no consistent, long-term agency
practice has been established; and it is consistent with the judicial
opinions that have most closely examined this issue. Having concluded
that the phrase ``significant portion of its range'' provides an
independent basis for listing and protecting the entire species, we
next turn to the meaning of ``significant'' to determine the threshold
for when such an independent basis for listing exists.
Although there are potentially many ways to determine whether a
portion of a species' range is ``significant,'' we conclude, for the
purposes of this finding, that the significance of the portion of the
range should be determined based on its biological contribution to the
conservation of the species. For this reason, we describe the threshold
for ``significant'' in terms of an increase in the risk of extinction
for the species. We conclude that a biologically based definition of
``significant'' best conforms to the purposes of the Act, is consistent
with judicial interpretations, and best ensures species' conservation.
Thus, for the purposes of this finding, and as explained further below,
a portion of the range of a species is ``significant'' if its
contribution to the viability of the species is so important that,
without that portion, the species would be in danger of extinction.
We evaluate biological significance based on the principles of
conservation biology using the concepts of redundancy, resiliency, and
representation. Resiliency describes the characteristics of a species
and its habitat that allow it to recover from periodic disturbance.
Redundancy (having multiple populations distributed across the
landscape) may be needed to provide a margin of safety for the species
to withstand catastrophic events. Representation (the range of
variation found in a species) ensures that the species' adaptive
capabilities are conserved. Redundancy, resiliency, and representation
are not independent of each other, and some characteristic of a species
or area may contribute to all three. For example, distribution across a
wide variety of habitat types is an indicator of representation, but it
may also indicate a broad geographic distribution contributing to
redundancy (decreasing the chance that any one event affects the entire
species), and the likelihood that some habitat types are less
susceptible to certain threats, contributing to resiliency (the ability
of the species to recover from disturbance). None of these concepts is
intended to be mutually exclusive, and a portion of a species' range
may be determined to be ``significant'' due to its contributions under
any one or more of these concepts.
For the purposes of this finding, we determine if a portion's
biological contribution is so important that the portion qualifies as
``significant'' by asking whether, without that portion, the
representation, redundancy, or resiliency of the species would be so
impaired that the species would have an increased vulnerability to
threats to the point that the overall species would be in danger of
extinction (i.e., would be ``endangered''). Conversely, we would not
consider the portion of the range at issue to be ``significant'' if
there is sufficient resiliency, redundancy, and representation
elsewhere in the species' range that the species would not be in danger
of extinction throughout its range if the population in that portion of
the range in question became extirpated (extinct locally).
We recognize that this definition of ``significant'' (a portion of
the range of a species is ``significant'' if its contribution to the
viability of the species is so important that, without that portion,
the species would be in danger of extinction) establishes a threshold
that is relatively high. On the one hand, given that the consequences
of finding a species to be endangered or threatened in an SPR would be
listing the species throughout its entire range, it is important to use
a threshold for ``significant'' that is robust. It would not be
meaningful or appropriate to establish a very low threshold whereby a
portion of the range can be considered ``significant'' even if only a
negligible increase in extinction risk would result from its loss.
Because nearly any portion of a species' range can be said to
contribute some increment to a species'

[[Page 54308]]

viability, use of such a low threshold would require us to impose
restrictions and expend conservation resources disproportionately to
conservation benefit: Listing would be rangewide, even if only a
portion of the range of minor conservation importance to the species is
imperiled. On the other hand, it would be inappropriate to establish a
threshold for ``significant'' that is too high. This would be the case
if the standard were, for example, that a portion of the range can be
considered ``significant'' only if threats in that portion result in
the entire species' being currently endangered or threatened. Such a
high bar would not give the SPR phrase independent meaning, as the
Ninth Circuit held in Defenders of Wildlife v. Norton, 258 F.3d 1136
(9th Cir. 2001).
The definition of ``significant'' used in this finding carefully
balances these concerns. By setting a relatively high threshold, we
minimize the degree to which restrictions will be imposed or resources
expended that do not contribute substantially to species conservation.
But we have not set the threshold so high that the phrase ``in a
significant portion of its range'' loses independent meaning.
Specifically, we have not set the threshold as high as it was under the
interpretation presented by the Service in the Defenders litigation.
Under that interpretation, the portion of the range would have to be so
important that current imperilment there would mean that the species
would be currently imperiled everywhere. Under the definition of
``significant'' used in this finding, the portion of the range need not
rise to such an exceptionally high level of biological significance.
(We recognize that if the species is imperiled in a portion that rises
to that level of biological significance, then we should conclude that
the species is in fact imperiled throughout all of its range, and that
we would not need to rely on the SPR language for such a listing.)
Rather, under this interpretation, we ask whether the species would be
endangered everywhere without that portion (i.e., if that portion were
completely extirpated). In other words, the portion of the range need
not be so important that even the species being in danger of extinction
in that portion would be sufficient to cause the species in the
remainder of the range to be endangered; rather, the complete
extirpation (in a hypothetical future) of the species in that portion
would be required to cause the species in the remainder of the range to
be endangered.
The range of a species can theoretically be divided into portions
in an infinite number of ways. However, there is no purpose to
analyzing portions of the range that have no reasonable potential to be
significant or to analyzing portions of the range in which there is no
reasonable potential for the species to be endangered or threatened. To
identify only those portions that warrant further consideration, we
determine whether there is substantial information indicating that: (1)
The portions may be ``significant,'' and (2) the species may be in
danger of extinction there or likely to become so within the
foreseeable future. Depending on the biology of the species, its range,
and the threats it faces, it might be more efficient for us to address
the significance question first or the status question first. Thus, if
we determine that a portion of the range is not ``significant,'' we do
not need to determine whether the species is endangered or threatened
there; if we determine that the species is not endangered or threatened
in a portion of its range, we do not need to determine if that portion
is ``significant.'' In practice, a key part of the determination that a
species is in danger of extinction in a significant portion of its
range is whether the threats are geographically concentrated in some
way. If the threats to the species are essentially uniform throughout
its range, no portion is likely to warrant further consideration.
Moreover, if any concentration of threats to the species occurs only in
portions of the species' range that clearly would not meet the
biologically based definition of ``significant,'' such portions will
not warrant further consideration.
We evaluated the current range of the White River Valley skipper to
determine if there is any apparent geographic concentration of the
primary stressors potentially affecting the subspecies including water
and land development, livestock grazing, nonnative species invasion,
agriculture, mining and energy development, climate change, and limited
range and small population size. On the basis of our review, we found
no geographic concentration of potential threats either on public or
private lands to suggest that the White River Valley skipper may be in
danger of extinction in that portion of its range. We found no area
within the range of the White River Valley skipper where the potential
threats are significantly concentrated or substantially greater than in
other portions of its range. We also found that lost historical range
does not constitute a significant portion of the range for the White
River Valley skipper because there is no information indicating that
there has been a range contraction for this subspecies. Therefore, we
find factors affecting the subspecies are essentially uniform
throughout its range, indicating no portion of the skipper's range
warrants further consideration of possible status as an endangered or
threatened species under the Act.
We found no information to indicate that the White River Valley
skipper is in danger of extinction now, nor is it likely to become
endangered within the foreseeable future, throughout all or a
significant portion of its range. Therefore, listing the White River
Valley skipper as an endangered or threatened species under the Act is
not warranted at this time.
We request that you submit any new information concerning the
status of, or threats to, the White River Valley skipper to our Nevada
Fish and Wildlife Office (see ADDRESSES section) whenever it becomes
available. New information will help us monitor the White River Valley
skipper and encourage its conservation. If an emergency situation
develops for the White River Valley skipper or any other species, we
will act to provide immediate protection.

Species Information for the Steptoe Valley Crescentspot

Taxonomy and Species Description

We accept the characterization of the Steptoe Valley crescentspot
(Phyciodes cocyta arenacolor) as a valid subspecies based on its
description by Austin (1998b, p. 577) and recent updated nomenclature
(NatureServe 2009b, p. 1; A. Warren, pers. comm., cited in WildEarth
Guardians 2010, p. 34). This subspecies was described by Austin (1998b,
p. 577) from specimens collected in Steptoe Valley at Warm Springs,
White Pine County, Nevada. This subspecies is in the Nymphalidae family
(Austin 1998a, p. 843). Male wingspan ranges from 0.67 to 0.74 in
(17.0-18.8 mm). The upperside is orange and black. The margin is
broadly black with a marginal spot. The hindwing has a broad black
margin. The submargin (on the wing, just inside marginal zone) has a
series of black dots. The fringes of both wings are dark grayish and
not distinctly checkered with white. The underside of the forewing is
paler (yellower) than the upperside. The margin and submargin are
brownish and interrupted with some yellow areas. The hindwing is
yellowish. A small brownish patch occurs along the middle of the outer

[[Page 54309]]

margin, which also has a distinct submarginal crescent (Austin 1998b,
p. 577). Females are slightly larger and range from 0.72 to 0.79 in
(18.2-20.0 mm). The upperside is a paler orange than the male's with a
forewing that is cream colored postmedian and creamy-orange on the
submargin. The black is more extensive than on the male. The hindwing
is like that of the male but the black is broader, separating the rows
of dots. The underside of the forewing is like that of the male's but
the postmedian is pale as on the upperside. The underside of the
hindwing is whitish (Austin 1998b, p. 577). Please refer to Austin
(1998b, p. 577) for a more detailed description of this subspecies.

Distribution and Habitat

Descriptions of locations where the Steptoe Valley crescentspot has
been found are vague. Austin (1993, pp. 8-9) and others (Austin 1998b,
p. 577; Austin and Leary 2008, p. 102) found the Steptoe Valley
crescentspot in the moist flats adjacent to Duck Creek from Warm
Springs (the type locality (Austin 1998b, p. 577)) south to northwest
of McGill (in unspecified locations) in Steptoe Valley, White Pine
County, Nevada. This is a distance of approximately 18 mi (29 km) where
both private and BLM lands occur along Duck Creek. More specific
locations include Bassett Lake (private lands) located along Duck Creek
Slough (Austin 1993, p. 9; NNHP 2010). Occurrences have been reported
by NNHP (2006, p. 42) at Monte Neva Hot Springs (on private and BLM
lands) and near McGill (on private and BLM lands), White Pine County,
Nevada. Monte Neva Hot Springs is located about 1 mi (1.6 km) west of
Warm Springs and about 1 mi (1.6 km) west of Duck Creek. A population
may be located near the Ruby Mountains (unspecified locations) (Boyd,
pers. comm. 2012a, p. 2). The NNHP (2009, p. 7) indicates three Nevada
occurrences, but the locations are not identified. The size of each
known occupied site and the extent of this subspecies' host plant, or
host plant abundance, has not been reported.

Biology

Adults are known to fly as one brood (Austin 1993, p. 9) during
early July to mid-August (Austin 1993, p. 9; 1998b, p. 577). Though
adult nectar sources have not been reported, it is possible that they
nectar on a variety of plants that are in flower during their flight
period. Aster ascendens (western aster, longleaf aster), now known as
Symphyotrichum ascendens (http://en.wikipedia.org Web site accessed
April 25, 2012), has been documented as a larval host plant (Austin and
Leary 2008, p. 102). This perennial forb occurs in most counties in
Nevada, including Elko, Eureka, White Pine, Nye, and Lincoln (http://www.plants.udsa.gov Web site accessed April 24, 2012). It can be found
throughout the western United States (http://www.plants.udsa.gov Web
site accessed April 24, 2012). It grows in many habitats including
meadows and disturbed areas (Hickman 1993, p. 206; http://en.wikipedia.org Web site accessed April 25, 2012).
There is little biological information available at the subspecies
level, but some inferences can be made from biological information from
related species at the species level. Information for the orange
crescent (Phyciodes cocyta=pascoensis) indicates eggs are pale green
and are laid in clusters under host plant leaves (Scott 1986, p. 310;
NatureServe 2009b, p. 1). Larvae eat leaves, and no nests are
constructed (Scott 1986, p. 311). Adults are local and sip flower
nectar and mud, and males patrol during the day near host plants in
valley bottoms seeking females (Scott 1986, p. 311).
The best available information does not include surveys documenting
this subspecies' population dynamics, its overall abundance, number or
size of populations, number of extirpated populations, if any, or
population trends.

Five-Factor Evaluation for the Steptoe Valley Crescentspot

Information pertaining to the Steptoe Valley crescentspot in
relation to the five factors provided in section 4(a)(1) of the Act is
discussed below.

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

Potential factors that may affect the habitat or range of the
Steptoe Valley crescentspot are discussed in this section, including:
(1) Water development, (2) livestock grazing, (3) nonnative plant
invasion, (4) agriculture, (5) mining and energy development, and (6)
climate change.
Water Development
For general background information on water development, please
refer to the Water Development section under Factor A. The Present or
Threatened Destruction, Modification, or Curtailment of Its Habitat or
Range in the Five-Factor Evaluation for the White River Valley Skipper.
Austin (1993, pp. 9-10) and Austin et al. (in litt. 2000, p. 2)
state that water table changes may impact the Steptoe Valley
crescentspot; however, specific information is not provided to support
this claim. Since the Steptoe Valley crescentspot is associated with
moist flats near wetland areas, potential adverse impacts to aquatic
habitat could result in adverse impacts to the butterfly's habitat
(e.g., drying of moist habitat and reductions in larval or nectar plant
abundance). The NNHP (2007, p. 42) states that various wetland areas in
Steptoe Valley have been degraded or converted to other land uses,
including water development (including Bassett Lake--25 percent; Duck
Creek--30 percent, two of several locations where this subspecies has
been observed). The NNHP (2007) does not delineate these various areas
in Steptoe Valley on a map or define them in terms of acreage;
therefore, the amount of Steptoe Valley crescentspot habitat or the
total number of occupied sites that may occur (made difficult because
locations where the skipper has been seen are not specific) within
these areas and may be impacted are not documented. The extent to which
the various land use practices have degraded or converted these various
areas is also not individually delineated or quantified by NNHP (2007).
Therefore, we cannot determine the amount of overlap between the
estimated wetland impacts identified by the NNHP and the distribution
of the Steptoe Valley crescentspot.
Bassett Lake is a manmade reservoir (about 10 ac (4 ha) in size)
constructed years ago with water control capabilities (Mabey 2012,
pers. comm.). The amount of Steptoe Valley crescentspot habitat that
may have been impacted at the time of construction is unknown, and it
is unknown whether this subspecies' habitat near Bassett Lake and along
Duck Creek has been enhanced due to a more consistent water supply
provided by Bassett Lake and its flow releases. The Monte Neva Hot
Springs is about 5 to 10 ac (2-4 ha) in size with approximately 250 to
300 ac (101-121 ha) of associated habitat; the springs are located on
private land. Water from the hot springs has been diverted for at least
40 years (NNHP in litt., 2007, p. 2). The amount of habitat used by the
subspecies in this area is not known.
The Steptoe Valley hydrographic area is a ``designated'' basin by
the NSE and permitted groundwater rights approach or exceed the
estimated average annual recharge of the basin (Table 2). As a
``designated'' basin, the NSE has authority under NRS Sec. 534.120 to
establish additional rules, regulations, or orders to protect the
basin's water resources (SNWA, in litt. 2011, p. 41). If such
additional rules, regulations, or orders are established, they may also

[[Page 54310]]

provide some protection to species dependent on these water resources,
such as the Steptoe Valley crescentspot. A preferred use for industrial
(power generation) has been identified for this basin.
The petition raises concerns about the effects of the proposed SNWA
water development project in central eastern Nevada on the Steptoe
Valley crescentspot (WildEarth Guardians 2010, p. 36). The butterfly
could be impacted by the proposed project due to its habitat being
impacted by project construction or operation (BLM 2011a, p. 3.6-27).
However, the Steptoe Valley crescentspot was not detected during the
project's ROW surveys (BLM 2011a, pp. 3.6-18-3.6-19). Based on the
groundwater flow model estimate for 200 years post full buildout (BLM
2011a, p. 3.3-102), this butterfly's occupied areas are located outside
of the greater than 10-foot (3.0-m) drawdown contour (or any other
contour range). While the Service recognizes that uncertainties remain
regarding potential impacts to water resources from SNWA's project,
within and outside of the 10-foot (3.0-m) drawdown, there are currently
no anticipated impacts to the Steptoe Valley crescentspot from SNWA's
proposed project.
Human water demands have impacted wetland areas in Steptoe Valley
over the decades. However, the best available information does not
indicate that impacts due to water development activities are
negatively impacting this subspecies. Actions regarding water
management in Steptoe Valley crescentspot habitat in the future would
be addressed in consideration of Nevada water law. We did not receive
any information as a result of our 90-day petition finding notice, nor
did we locate information indicating that water development, either in
general or specifically from the SNWA proposed project, is impacting
the subspecies' habitat. Therefore, the best available information does
not indicate that water development is modifying the subspecies'
habitat to an extent that it represents a threat to this subspecies now
or in the future.
Livestock Grazing
For general background information on livestock grazing, please
refer to the Livestock Grazing section under Factor A. The Present or
Threatened Destruction, Modification, or Curtailment of Its Habitat or
Range in the Five-Factor Evaluation for the White River Valley Skipper.
Austin (1993, pp. 9-10) and Austin et al. (in litt. 2000, p. 2)
state that overgrazing (including trampling) may impact the Steptoe
Valley crescentspot; however, specific information is not provided to
support this claim. The NNHP (2007, p. 42) states that a portion of
wetland areas in Steptoe Valley have been degraded or converted to
other land uses, including livestock grazing. A site visit by a BLM
employee in 1992 reported cattle grazing on private land west of Duck
Creek Slough; the slough did not appear to be heavily impacted by
cattle and looked in good condition (Barber in litt. 1992a, p. 1).
Locations for the Steptoe Valley crescentspot occur on or near BLM's
Steptoe Allotment (BLM 2010b, Appendix II, p. 10; Lichtler, 2012, pers.
comm.), Duck Creek Flat Allotment (Barber in litt. 1993, p. 1;
Lichtler, 2012, pers. comm.), and the Heuser Mountain Allotment (Barber
in litt. 1993, p. 2; Lichtler, 2012, pers. comm.), but also occur on
private land. It is not known how livestock grazing is managed on
private land, but general knowledge of these areas indicate they are
not heavily grazed and habitat conditions are good (Mabey 2012, pers.
comm.). Current range conditions on BLM allotments that may support
Steptoe Valley crescentspot habitat have improved in the last 5 years
through grazing permit renewals with implementation of terms and
conditions and lower utilization rates, and this would improve any
habitat for the Steptoe Valley crescentspot (Mabey 2012, pers. comm.).
Livestock grazing occurs at the Monte Neva Hot Springs area; about 30
head of cattle and a few domestic horses have access to the area,
likely year-round (NNHP in litt., 2007, p. 1).
The best available information does not indicate declines in the
larval host plant Aster ascendens or adult nectar plant species in
occupied Steptoe Valley crescentspot habitat due to livestock grazing.
The larval host plant is widely distributed in Nevada and other western
States and grows in a wide variety of habitats, including disturbed
sites (see Biology section). One potential adult nectar plant species,
Castilleja salsuginosa (Monte Neva paintbrush), is thriving at Monte
Neva Hot springs and is apparently not being adversely affected by
livestock grazing (NNHP in litt., 2007, p. 1). Activities involving
grazing management within the Steptoe Valley crescentspot habitat on
BLM lands are addressed in consideration of the Ely District Record of
Decision and Approved RMP (BLM 2008a), BLM's authority under
Regulations on Grazing Administration Exclusive of Alaska, BLM's 6840
Manual (BLM 2008b), and possibly NEPA, per our discussion of these
authorities in our analysis above for the White River Valley skipper.
We did not receive any additional information as a result of the 90-day
petition finding notice, nor did we locate information indicating that
livestock grazing is negatively impacting the habitat or populations of
the Steptoe Valley crescentspot. Thus, the best available information
does not indicate that livestock grazing is modifying the subspecies'
habitat to the extent that it represents a threat to this subspecies
now or in the future.
Nonnative Plant Invasion
For general background information on nonnative plant invasion,
please refer to the Nonnative Plant Invasion section under Factor A.
The Present or Threatened Destruction, Modification, or Curtailment of
Its Habitat or Range in the Five-Factor Evaluation for the White River
Valley Skipper.
The NNHP (2007, p. 42) states that a portion of Steptoe Valley's
wetland areas have been degraded or converted to other land uses,
including nonnative species invasion. Although they are likely to occur
to some extent within the range of the Steptoe valley crescentspot,
nonnative invasive plant species are not known to be a problem in
Steptoe Valley crescentspot habitat (Mabey 2012, pers. comm.). There is
no information indicating that nonnative plants are adversely affecting
the Steptoe Valley crescentspot's larval host plant, Aster ascendens,
or the butterfly's adult nectar plants. Activities involving nonnative
plant species management within the Steptoe Valley crescentspot habitat
on BLM lands would be addressed in consideration of the Ely District
Record of Decision and Approved RMP (BLM 2008a), BLM's authority under
Regulations on Grazing Administration Exclusive of Alaska, the Plant
Protection Act of 2000, BLM's programmatic EIS for vegetation
treatments on BLM's administered lands in the western United States
(BLM 2007a), BLM's 6840 Manual (BLM 2008b), and possibly NEPA, as these
authorities are discussed in our analysis for White River Valley
skipper, above. Activities involving nonnative plant species management
and control on private lands within the Steptoe Valley crescentspot
habitat could also be addressed in consideration of the Plant
Protection Act of 2000. We did not receive any further information as a
result of our 90-day petition finding notice, nor did we locate
information indicating that nonnative or invasive plant species are
negatively impacting populations of the Steptoe Valley crescentspot.
Thus, the best available information does not indicate that

[[Page 54311]]

nonnative plant species are modifying the subspecies' habitat to the
extent that it represents a threat to this subspecies now or in the
future.
Agriculture
For general background information on agriculture, please refer to
the Agriculture section under Factor A. The Present or Threatened
Destruction, Modification, or Curtailment of Its Habitat or Range in
the Five-Factor Evaluation for the White River Valley Skipper.
The NNHP (2007, p. 42) states that a portion of Steptoe Valley's
wetland areas have been degraded or converted to other land uses,
including agriculture. Although agriculture (hayfields) is known to
occur near the Duck Creek-Bassett Lake and Monte Neva sites,
agriculture does not occur within Steptoe Valley crescentspot habitat
as the soils are not suitable because they are too moist and saline
(Mabey 2012, pers. comm.). The best available information does not
indicate that agriculture is occurring in areas that are occupied by
the Steptoe Valley crescentspot. We did not receive any information as
a result of the 90-day petition finding notice, nor did we locate
information that indicates agriculture is negatively impacting Steptoe
Valley crescentspot populations, host plants, or nectar sources.
Therefore, the best available information does not indicate that
agriculture is modifying the subspecies' habitat to the extent that it
represents a threat to this subspecies now or in the future.
Mining and Energy Development
For general background information on mining and energy
development, please refer to the Mining and Energy Development section
under Factor A. The Present or Threatened Destruction, Modification, or
Curtailment of Its Habitat or Range in the Five-Factor Evaluation for
the White River Valley Skipper.
The NNHP (2007, p. 42) states that a portion of wetland areas in
Steptoe Valley have been degraded or converted to other land uses,
including mining and energy development. A copper ore smelter,
concentrator, and tailings facility was constructed in McGill in the
early 1900s and operated until the early 1980s (http://www.mii.org Web
site accessed April 26, 2012). It is not known the amount, if any, of
Steptoe Valley crescentspot habitat that may have been impacted at the
time of the facility's construction. During the late 1980s and early
1990s the site was reclaimed; the tailings area was reclaimed as
pasture for livestock grazing (http://www.mii.org Web site accessed
April 26, 2012).
Though the Steptoe Valley crescentspot is known from the project
area for the Southwest Intertie Project, impacts to it were not
identified (BLM 1993, pp. 3-75-3-89). This subspecies was also not
observed during wildlife surveys conducted for the One Nevada
Transmission Line Project (BLM 2010c, Appendix 3D, Table 2, pp. 1-5).
Actions involving mineral and energy development within Steptoe Valley
crescentspot habitat on BLM-administered lands would be addressed in
consideration of the Ely District Record of Decision and Approved RMP
(BLM 2008a), the FLPMA of 1976, the Mineral Leasing Act of 1920, BLM's
6840 Manual (BLM 2008b), and NEPA, per our analysis of these
authorities above for the White River Valley skipper. The best
available information does not indicate energy development is impacting
Steptoe Valley crescentspot habitat or populations. We did not receive
any additional information as a result of our 90-day petition finding
notice, nor did we locate information indicating that mining or energy
development is negatively impacting the subspecies' habitat. Thus, the
best available information does not indicate that mining or energy
development is modifying the subspecies' habitat to an extent that they
represent a threat to this subspecies now or in the future.
Climate Change
For general background information on climate change, please refer
to the Climate Change section under Factor A. The Present or Threatened
Destruction, Modification, or Curtailment of Its Habitat or Range in
the Five-Factor Evaluation for the White River Valley Skipper.
While the petition asserts that climate change may impact Steptoe
Valley crescentspot (WildEarth Guardians 2010, p. 40), it is difficult
to predict local climate change impacts, due to substantial uncertainty
in trends of hydrological variables, limitations in spatial and
temporal coverage of monitoring networks, and differences in the
spatial scales of global climate models and hydrological models (Bates
et al. 2008, p. 3). We found no information on how climate change may
impact the Steptoe Valley crescentspot's host plant, Symphyotrichum
ascendens, or adult nectar sources. In general, increasing temperatures
and drought frequency, more winter precipitation in the form of rain,
possible decreases in summer rain, and earlier, rapid snowmelt could
impact the host plant by causing physiological stress, altering
phenology, reducing recruitment events, and reducing seed
establishment. However, at this time, it is difficult to predict local
climate change impacts to Symphyotrichum ascendens or Steptoe Valley
crescentspot's adult nectar sources and how individual plant species
will react to climate change. Thus, while information indicates that
climate change has the potential to affect vegetation and habitats used
by the Steptoe Valley crescentspot in the Great Basin, there is much
uncertainty regarding which habitat attributes could be affected, and
the timing, magnitude, and rate of their change as it relates to this
subspecies.
We did not receive any information as a result of our 90-day
petition finding notice, nor did we locate specific information that
indicates climate change is negatively impacting Steptoe Valley
crescentspot populations or their habitats. Therefore, the best
available information does not indicate that climate change is
modifying the subspecies' habitat to an extent that it represents a
threat to this subspecies now or is likely to in the future.
Summary of Factor A
While activities such as water development, livestock grazing,
nonnative species invasion, agriculture, and mining and energy
development may be impacting a portion of wetland areas in Steptoe
Valley, available information does not indicate that these impacts are
negatively impacting occupied Steptoe Valley crescentspot habitat. The
available information does not indicate that these activities, or
climate change, are negatively impacting populations of Steptoe Valley
crescentspot. Since the Steptoe Valley crescentspot is associated with
wetland areas, impacts from water development could impact the
subspecies; however, known occupied locations are outside the greater
than 10-foot (3.0-m) drawdown contour for the SNWA proposed project,
and impacts are not anticipated. While information indicates that
climate change has the potential to affect vegetation used by this
subspecies, much uncertainty remains regarding which plant attributes
may be affected, and the timing, magnitude, and rate of their change.
We conclude based on the best scientific and commercial information
available that the present or threatened destruction, modification, or
curtailment of its habitat or range does not currently pose a threat to
the Steptoe Valley crescentspot, nor is it likely to become a threat to
the subspecies in the future.

[[Page 54312]]

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

For general background information on overutilization, please refer
to the discussion on collecting under Factor B. Overutilization for
Commercial, Recreational, Scientific, or Educational Purposes in the
Five-Factor Evaluation for the White River Valley Skipper.
We are unaware of any studies analyzing impacts of removal of
individuals from populations of the Steptoe Valley crescentspot. Austin
(1998b, p. 577) indicates 39 males and 10 females were collected
between 1981 and 1989 at one site. No additional information is known
about the numbers of specimens collected in the past, and we are not
aware of any ongoing or current collecting of this subspecies. Given
the low number of individuals collected over this 8-year period, the
length of time since the collections were made, and the lack of
information about the relative impact to the populations, the available
information does not indicate that collection may be a threat to this
subspecies.
There has been no information presented that documents that
overutilization has led to the loss of populations or a significant
reduction in numbers of individuals for this subspecies. Therefore, we
conclude based on the best scientific and commercial information
available that overutilization for commercial, recreational,
scientific, or educational purposes does not currently pose a threat to
the Steptoe Valley crescentspot, nor is it likely to become a threat to
the subspecies in the future.

Factor C. Disease or Predation

We found no information on the incidence of disease in the Steptoe
Valley crescentspot.
Predation by other species, such as birds or insects, on eggs,
larvae, pupae, or adult Steptoe Valley crescentspots is assumed, but we
found no information indicating that predation levels are any greater
than naturally occurring levels typical of the biological community in
which the Steptoe Valley crescentspot occurs.
Available information does not indicate that there are impacts from
disease or predation on the Steptoe Valley crescentspot. Therefore, we
conclude that the best scientific and commercial information available
does not indicate that disease or predation currently pose a threat to
the Steptoe Valley crescentspot, nor is either likely to become a
threat to the subspecies in the future.

Factor D. The Inadequacy of Existing Regulatory Mechanisms

The discussion of existing regulatory mechanisms under Factor D for
the White River Valley skipper is hereby incorporated into this
discussion for the Steptoe Valley crescentspot. As discussed above
under Factor D for the White River Valley skipper, Nevada State law
pertaining to wildlife does not offer protection to the Steptoe Valley
crescentspot specifically because it is an invertebrate species not
classified as wildlife. Although not protected by State wildlife law,
the best available information, as discussed in Factor B, does not
indicate that collection or other forms of overutilization is a threat
to the Steptoe Valley crescentspot. In addition, the State's water law
may offer some protection to species dependent on water resources such
as the Steptoe Valley crescentspot as it occurs in a ``designated''
basin with a preferred use identified.
A portion of habitat for the Steptoe Valley crescentspot occurs on
Federal lands administered by BLM. Numerous policies, guidance, and
laws have been developed to assist the agency in management of these
lands (see Factor D discussion under White River Valley skipper). BLM
policies and guidance address species of concern, actions covered by
RMPs, and regulatory authority for grazing and oil and gas leasing and
operating activities. As discussed under Factor A, the best available
information does not indicate that activities such as livestock
grazing, nonnative species invasion, and mining and energy development
that are regulated by various policies, guidance, and laws on Federal
lands are negatively impacting Steptoe Valley crescentspot populations.
We conclude based on the best scientific and commercial information
available that the inadequacy of existing regulatory mechanisms does
not currently pose a threat to the Steptoe Valley crescentspot, nor is
it likely to become a threat to the subspecies in the future.

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

Potential other natural or manmade factors that may affect the
continued existence of the Steptoe Valley crescentspot are discussed in
this section and include: (1) Limited range and (2) small population
size(s).
For general background information on other natural or manmade
factors which could affect the Steptoe Valley crescentspot, please
refer to the discussion on limited distribution and population size
under Factor E. Other Natural or Manmade Factors Affecting Its
Continued Existence in the Five-Factor Evaluation for the White River
Valley Skipper.
As indicated earlier, the Steptoe Valley crescentspot occurs at
locations along Duck Creek and at Monte Neva Hot Springs in Steptoe
Valley and possibly near the Ruby Mountains. Little information is
available related to its distribution and numbers of populations, and
no information is available regarding population sizes, loss of
populations, if any, or population trends for the Steptoe Valley
crescentspot. Information pertaining to the aerial extent of habitat or
populations is not available. The best available information does not
include comprehensive surveys for this subspecies. Without data to
indicate population trends, it is difficult to support claims of
adverse impacts to the Steptoe Valley crescentspot. We found no
information on connections between chance events and population impacts
for the Steptoe Valley crescentspot. Since this subspecies is
distributed over different areas, potential impacts due to stochastic
events is reduced. In the absence of chance events connected to known
populations, we do not consider small population numbers or limited
range by themselves to be threats to this subspecies. The best
available information does not indicate the Steptoe Valley crescentspot
is negatively impacted by limited range or small population numbers. We
conclude based on the best scientific and commercial information
available that other natural or manmade factors do not currently pose a
threat to the Steptoe Valley crescentspot, nor are they likely to
become a threat to the subspecies in the future.

Synergistic Interactions Between Threat Factors

We have evaluated individual threats to the Steptoe Valley
crescentspot. This subspecies faces potential threats from water
development, livestock grazing, nonnative plant invasion, agriculture,
mining and energy development, limited range, small population size,
and climate change. In considering whether the threats to a species may
be so great as to warrant listing under the Act, we must look beyond
the possible impacts of potential threats in isolation and consider the
potential cumulative impacts of all of the threats facing a species.
In making this finding, we considered whether there may be
cumulative effects to the Steptoe Valley crescentspot from the combined
impacts of the existing

[[Page 54313]]

stressors such that even if each stressor individually does not result
in population-level impacts, that cumulatively the effects may be
significant. We considered whether the combined effects of water
development and mining and energy development may result in a
significant impact to the Steptoe Valley crescentspot because these
potential impacts have the potential to result in some level of habitat
loss. However, we conclude that synergistic effects between water
development and mining and energy development are unlikely to result in
a significant overall population impact to the Steptoe Valley
crescentspot because water development activities have been ongoing in
the valley, and the proposed SNWA water development project is not
anticipated to cause impacts to this subspecies because sites occupied
by the butterfly are located outside of the estimated project impact
area. Also, impacts from mining and energy development are not found to
be occurring in the butterfly's habitat.
While livestock grazing and nonnative plant invasion could impact
the Steptoe Valley crescentspot and its habitat, observations of
private land within the subspecies' habitat that are being grazed look
to be in good condition; changes in livestock grazing management on BLM
sites that may be occupied by the butterfly have improved habitat
conditions for this subspecies; and nonnative plant species invasion is
not known to be a concern on either private or public lands. We
conclude that livestock grazing and nonnative plant species invasion
impacts combined with impacts from water development would not be of
sufficient severity, frequency, or geographic scope to result in
significant habitat impacts or cause population-level impacts to the
Steptoe Valley crescentspot. Agriculture and mining and energy
development were not found to occur within this subspecies' habitat
and, therefore, will not have a cumulative impact on the Steptoe Valley
crescentspot.
Limited range and small population size could make the Steptoe
Valley crescentspot more vulnerable to potential threats discussed
above. However, we cannot conclude that synergistic effects between
limited range and small population size and other potential threats are
operative threats to the continued existence of the Steptoe Valley
crescentspot given the lack of information on the range and population
size of this butterfly. There is no information on population size or
change in population abundance for the Steptoe Valley crescentspot, and
the limited information on occurrence (distribution) is insufficient to
define this butterfly's range.
Synergistic interactions are possible between effects of climate
change and effects of other potential threats such as livestock grazing
and nonnative plant invasion. Increases in carbon dioxide and
temperature and changes in precipitation are likely to affect
vegetation, and the Steptoe Valley crescentspot is closely associated
with the presence of vegetation. However, it is difficult to project
how climate change will affect vegetation because certain plant species
may increase in cover while other species may decrease. Uncertainty
about how different plant species will respond under climate change,
combined with uncertainty about how changes in plant species
composition would affect suitability of Steptoe Valley crescentspot
habitat, make projecting possible synergistic effects of climate change
on the Steptoe Valley crescentspot too speculative.

Finding for the Steptoe Valley Crescentspot

As required by the Act, we considered the five factors is assessing
whether the Steptoe Valley crescentspot is an endangered or threatened
species throughout all of its range. We examined the best scientific
and commercial information available regarding the past, present, and
future threats faced by this subspecies.
Factors potentially affecting the Steptoe Valley crescentspot,
including water development, livestock grazing, nonnative species
invasion, agriculture, mining and energy development, or climate
change, and limited range and small population size, are either limited
in scope or lack documentation that they are occurring in occupied
habitat and adversely impacting the subspecies. Though climate change
may be affecting the Steptoe Valley crescentspot and its habitats and
effects are likely to increase in the future, available information
does not support a determination that climate change has or will result
in a population-level impact to this subspecies. Available information
does not indicate that overutilization, disease, or predation is a
threat to the Steptoe Valley crescentspot. Lastly, the available
information does not indicate that existing regulatory mechanisms are
inadequate to protect the subspecies from potential threats.
Furthermore, there is no evidence to indicate that the combined factors
acting together are a threat to the Steptoe Valley crescentspot. Based
on our review of the best scientific and commercial information
available, we find these stressors, either singly or in combination
with one another, are not threats to the Steptoe Valley crescentspot or
its habitat.
We found no information to indicate that threats are of sufficient
imminence, intensity, or magnitude such that the Steptoe Valley
crescentspot is in danger of extinction (endangered) or likely to
become endangered within the foreseeable future (threatened),
throughout all of its range. Therefore, we find that listing the
Steptoe Valley crescentspot as an endangered or threatened species is
not warranted throughout its range.

Significant Portion of the Range

Having determined that the Steptoe Valley crescentspot does not
meet the definition of an endangered or a threatened species, we must
next consider whether there are any significant portions of the range
where the Steptoe Valley crescentspot is in danger of extinction or is
likely to become endangered in the foreseeable future. The Act defines
``endangered species'' as any species which is ``in danger of
extinction throughout all or a significant portion of its range,'' and
``threatened species'' as any species which is ``likely to become an
endangered species within the foreseeable future throughout all or a
significant portion of its range.'' 16 U.S.C. 1532(6) and 1532(20). The
definition of ``species'' is also relevant to this discussion. The Act
defines ``species'' as follows: ``The term `species' includes any
subspecies of fish or wildlife or plants, and any distinct population
segment of any species of vertebrate fish or wildlife which interbreeds
when mature.'' 16 U.S.C. 1532(16). The phrase ``significant portion of
its range'' (SPR) is not defined by the statute, and we have never
addressed in our regulations: (1) The consequences of a determination
that a species is either endangered or likely to become so throughout a
significant portion of its range, but not throughout all of its range;
or (2) what qualifies a portion of a range as ``significant.''
Two recent district court decisions have addressed whether the SPR
language allows the Service to list or protect less than all members of
a defined ``species'': Defenders of Wildlife v. Salazar, 729 F. Supp.
2d 1207 (D. Mont. 2010), concerning the Service's delisting of the
Northern Rocky Mountains gray wolf (74 FR 15123, April 2, 2009); and
WildEarth Guardians v. Salazar, 2010 U.S. Dist. LEXIS 105253 (D. Ariz.
September 30, 2010), concerning the Service's 2008 finding on a
petition to list the

[[Page 54314]]

Gunnison's prairie dog (73 FR 6660, February 5, 2008). The Service had
asserted in both of these determinations that, under the Act, it had
authority, in effect, to protect only some members of a ``species,'' as
defined by the Act (i.e., species, subspecies, or DPS). Both courts
ruled that the determinations were arbitrary and capricious on the
grounds that this approach violated the plain and unambiguous language
of the Act. The courts concluded that reading the SPR language to allow
protecting only a portion of a species' range is inconsistent with the
Act's definition of ``species.'' The courts concluded that once a
determination is made that a species (i.e., species, subspecies, or
DPS) meets the definition of ``endangered species'' or ``threatened
species,'' it must be placed on the list in its entirety and the Act's
protections applied consistently to all members of that species
throughout its range (subject to modification of protections through
special rules under sections 4(d) and 10(j) of the Act).
Consistent with that interpretation, and for the purposes of this
finding, we interpret the phrase ``significant portion of its range''
in the Act's definitions of ``endangered species'' and ``threatened
species'' to provide an independent basis for listing. Thus there are
two situations (or factual bases) under which a species would qualify
for listing: A species may be endangered or threatened throughout all
of its range, or a species may be endangered or threatened in only a
significant portion of its range. If a species is in danger of
extinction throughout an SPR, it, the species, is an ``endangered
species.'' The same analysis applies to ``threatened species.'' Based
on this interpretation and supported by existing case law, the
consequence of finding that a species is endangered or threatened in
only a significant portion of its range is that the entire species
shall be listed as endangered or threatened, respectively, and the
Act's protections shall be applied across the species' entire range.
We conclude, for the purposes of this finding, that interpreting
the SPR phrase as providing an independent basis for listing is the
best interpretation of the Act because it is consistent with the
purposes and the plain meaning of the key definitions of the Act; it
does not conflict with established past agency practice (i.e., prior to
the 2007 Solicitor's Opinion), as no consistent, long-term agency
practice has been established; and it is consistent with the judicial
opinions that have most closely examined this issue. Having concluded
that the phrase ``significant portion of its range'' provides an
independent basis for listing and protecting the entire species, we
next turn to the meaning of ``significant'' to determine the threshold
for when such an independent basis for listing exists.
Although there are potentially many ways to determine whether a
portion of a species' range is ``significant,'' we conclude, for the
purposes of this finding, that the significance of the portion of the
range should be determined based on its biological contribution to the
conservation of the species. For this reason, we describe the threshold
for ``significant'' in terms of an increase in the risk of extinction
for the species. We conclude that a biologically based definition of
``significant'' best conforms to the purposes of the Act, is consistent
with judicial interpretations, and best ensures species' conservation.
Thus, for the purposes of this finding, and as explained further below,
a portion of the range of a species is ``significant'' if its
contribution to the viability of the species is so important that,
without that portion, the species would be in danger of extinction.
We evaluate biological significance based on the principles of
conservation biology using the concepts of redundancy, resiliency, and
representation. Resiliency describes the characteristics of a species
and its habitat that allow it to recover from periodic disturbance.
Redundancy (having multiple populations distributed across the
landscape) may be needed to provide a margin of safety for the species
to withstand catastrophic events. Representation (the range of
variation found in a species) ensures that the species' adaptive
capabilities are conserved. Redundancy, resiliency, and representation
are not independent of each other, and some characteristic of a species
or area may contribute to all three. For example, distribution across a
wide variety of habitat types is an indicator of representation, but it
may also indicate a broad geographic distribution contributing to
redundancy (decreasing the chance that any one event affects the entire
species), and the likelihood that some habitat types are less
susceptible to certain threats, contributing to resiliency (the ability
of the species to recover from disturbance). None of these concepts is
intended to be mutually exclusive, and a portion of a species' range
may be determined to be ``significant'' due to its contributions under
any one or more of these concepts.
For the purposes of this finding, we determine if a portion's
biological contribution is so important that the portion qualifies as
``significant'' by asking whether, without that portion, the
representation, redundancy, or resiliency of the species would be so
impaired that the species would have an increased vulnerability to
threats to the point that the overall species would be in danger of
extinction (i.e., would be ``endangered''). Conversely, we would not
consider the portion of the range at issue to be ``significant'' if
there is sufficient resiliency, redundancy, and representation
elsewhere in the species' range that the species would not be in danger
of extinction throughout its range if the population in that portion of
the range in question became extirpated (extinct locally).
We recognize that this definition of ``significant'' (a portion of
the range of a species is ``significant'' if its contribution to the
viability of the species is so important that, without that portion,
the species would be in danger of extinction) establishes a threshold
that is relatively high. On the one hand, given that the consequences
of finding a species to be endangered or threatened in an SPR would be
listing the species throughout its entire range, it is important to use
a threshold for ``significant'' that is robust. It would not be
meaningful or appropriate to establish a very low threshold whereby a
portion of the range can be considered ``significant'' even if only a
negligible increase in extinction risk would result from its loss.
Because nearly any portion of a species' range can be said to
contribute some increment to a species' viability, use of such a low
threshold would require us to impose restrictions and expend
conservation resources disproportionately to conservation benefit:
Listing would be rangewide, even if only a portion of the range of
minor conservation importance to the species is imperiled. On the other
hand, it would be inappropriate to establish a threshold for
``significant'' that is too high. This would be the case if the
standard were, for example, that a portion of the range can be
considered ``significant'' only if threats in that portion result in
the entire species' being currently endangered or threatened. Such a
high bar would not give the SPR phrase independent meaning, as the
Ninth Circuit held in Defenders of Wildlife v. Norton, 258 F.3d 1136
(9th Cir. 2001).
The definition of ``significant'' used in this finding carefully
balances these concerns. By setting a relatively high threshold, we
minimize the degree to which restrictions will be imposed or resources
expended that do not contribute substantially to species conservation.
But we have not set the

[[Page 54315]]

threshold so high that the phrase ``in a significant portion of its
range'' loses independent meaning. Specifically, we have not set the
threshold as high as it was under the interpretation presented by the
Service in the Defenders litigation. Under that interpretation, the
portion of the range would have to be so important that current
imperilment there would mean that the species would be currently
imperiled everywhere. Under the definition of ``significant'' used in
this finding, the portion of the range need not rise to such an
exceptionally high level of biological significance. (We recognize that
if the species is imperiled in a portion that rises to that level of
biological significance, then we should conclude that the species is in
fact imperiled throughout all of its range, and that we would not need
to rely on the SPR language for such a listing.) Rather, under this
interpretation, we ask whether the species would be endangered
everywhere without that portion (i.e., if that portion were completely
extirpated). In other words, the portion of the range need not be so
important that even the species being in danger of extinction in that
portion would be sufficient to cause the species in the remainder of
the range to be endangered; rather, the complete extirpation (in a
hypothetical future) of the species in that portion would be required
to cause the species in the remainder of the range to be endangered.
The range of a species can theoretically be divided into portions
in an infinite number of ways. However, there is no purpose to
analyzing portions of the range that have no reasonable potential to be
significant or to analyzing portions of the range in which there is no
reasonable potential for the species to be endangered or threatened. To
identify only those portions that warrant further consideration, we
determine whether there is substantial information indicating that: (1)
The portions may be ``significant,'' and (2) the species may be in
danger of extinction there or likely to become so within the
foreseeable future. Depending on the biology of the species, its range,
and the threats it faces, it might be more efficient for us to address
the significance question first or the status question first. Thus, if
we determine that a portion of the range is not ``significant,'' we do
not need to determine whether the species is endangered or threatened
there; if we determine that the species is not endangered or threatened
in a portion of its range, we do not need to determine if that portion
is ``significant.'' In practice, a key part of the determination that a
species is in danger of extinction in a significant portion of its
range is whether the threats are geographically concentrated in some
way. If the threats to the species are essentially uniform throughout
its range, no portion is likely to warrant further consideration.
Moreover, if any concentration of threats to the species occurs only in
portions of the species' range that clearly would not meet the
biologically based definition of ``significant,'' such portions will
not warrant further consideration.
We evaluated the current range of the Steptoe Valley crescentspot
to determine if there is any apparent geographic concentration of the
primary stressors potentially affecting the subspecies, including water
development, livestock grazing, nonnative species invasion,
agriculture, mining and energy development, climate change, limited
range, and small population size. On the basis of our review, we found
no geographic concentration of threats either on public or private
lands to suggest that the Steptoe Valley crescentspot may be in danger
of extinction in that portion of its range. We found no area within the
range of the Steptoe Valley crescentspot where the potential threats
are significantly concentrated or substantially greater than in other
portions of its range. We also found that lost historical range does
not constitute a significant portion of the range for the Steptoe
Valley crescentspot because there is no information indicating that
there has been a range contraction for this subspecies. Therefore, we
find factors affecting the subspecies are essentially uniform
throughout its range, indicating no portion of the butterfly's range
warrants further consideration of possible status as an endangered or
threatened species under the Act.
We found no information to indicate that the Steptoe Valley
crescentspot is in danger of extinction now, nor is it likely to become
endangered within the foreseeable future, throughout all or a
significant portion of its range. Therefore, listing the Steptoe Valley
crescentspot as an endangered or threatened species under the Act is
not warranted at this time.
We request that you submit any new information concerning the
status of, or threats to, the Steptoe Valley crescentspot to our Nevada
Fish and Wildlife Office (see ADDRESSES section) whenever it becomes
available. New information will help us monitor the Steptoe Valley
crescentspot and encourage its conservation. If an emergency situation
develops for the Steptoe Valley crescentspot or any other species, we
will act to provide immediate protection.

Species Information for Baking Powder Flat Blue Butterfly

Taxonomy and Species Description

We accept the characterization of the Baking Powder Flat blue
butterfly (Euphilotes bernardino minuta) as a valid subspecies based on
its description by Austin (1998c, p. 549). This subspecies is in the
Lycaenidae family (Austin 1998c, p. 539; 1998b, p. 841) and was an
unnamed segregate of the E. battoides complex in Nevada (Austin 1998c,
p. 549). The male's wingspan ranges from 0.35 to 0.40 inch (in) (9.0-
10.2 mm). The upper side of the male is purplish-blue with a black
outer margin (wing edge) of moderate width. Veins are black distally
(away from the point of attachment) on both wings. Submarginal orange
often occurs in posterior (behind or at the rear) cells on the
hindwing. Wing fringes are white and lightly checkered with gray. The
underside of the male's wings is grayish-white; there is a slight
posterior gray flush on the forewing and the hindwing has an orange
aurora (colored marginal band of hindwing) of moderate width (Austin
1998c, p. 549). The female's wingspan ranges from 0.43 to 0.97 in (9.7-
11.0 mm). The upper side of the wing is a dark brownish-gray and
slightly grayer basally. The hindwing has an orange aurora of moderate
width and is outlined with blackish marginal spots distally. Wing
fringes and the undersides are like that of the male (Austin 1998c, p.
549). Please refer to Austin (1998c, p. 549) for a more detailed
description of this subspecies.

Distribution and Habitat

Descriptions of locations where the Baking Powder Flat blue
butterfly has been found are vague, but this subspecies is only known
from the Baking Powder Flat area (on BLM lands) in Spring Valley, in
Lincoln and White Pine Counties, Nevada, a flat valley bottom with
scattered sand dunes (Austin 1998c, p. 550; Austin and Leary 2008, pp.
68-69). The type locality is located approximately 1.0 mi (1.6 km) from
Blind Spring in Baking Powder Flat (Spring Valley, White Pine County)
(Austin 1998c, p. 550). The Baking Powder Flat area also contains areas
of wetland-type habitats (wetlands, springs, seeps). The Baking Powder
Flat area contains the largest known contiguous habitat for the Baking
Powder Flat blue butterfly (BLM 2009a,

[[Page 54316]]

p. 20). In 1993, Austin (1993, p. 5) reported two occupied sites for
the Baking Powder Flat blue butterfly in the Baking Powder Flat area in
southern Spring Valley, and also suggested that other areas could
support the host plant (Austin 1993, pp. 5-6), indicating a possible
wider distribution of this butterfly. The only documented host plant,
Eriogonum shockleyi (Shockley's buckwheat), which the Baking Powder
Flat blue butterfly uses for both larval and adult life stages (see
Biology section below), is a perennial forb (http://www.plants.usda.gov, accessed January 6, 2012) and grows on relatively
hard and bare areas between the sand dunes in the Baking Powder Flat
area (Austin 1993, p. 5; 1998c, p. 550). In this area the plants occur
in large, open, loose mats (Kartesz 1987, pp. 282-283).
Throughout its range, Eriogonum shockleyi grows mostly on gravelly,
clayey, or sandy soils, or on rocky outcrops and ledges, in association
with Sarcobatus sp. (greasewood), Atriplex sp. (shadscale), and
Artemisia sp. (sagebrush) (Kartesz 1987, p. 282); it is not a wetland-
dependent species. The host plant (E. shockleyi) is common in Nevada,
occurring in Mineral, Esmeralda, Nye, Lincoln, Clark, White Pine, and
Elko Counties (Kartesz 1987, p. 282). It is also known to occur in
California, Idaho, Utah, Colorado, New Mexico, and Arizona (Kartesz
1987, p. 283; http://www.plants.usda.gov, accessed January 6, 2012).
Searches of nearby areas in southern Spring Valley did not reveal
additional colonies of the subspecies or its host plant (Austin 1993,
p. 5; 1998c, p. 550); however, Austin and Leary (2008, pp. 68-69) list
what appear to be seven discrete locations in the Baking Powder Flat
area where this subspecies (adults and larvae) has been seen between
1969 and 2002.
The NNHP database (2010) also indicates that this subspecies occurs
in the Baking Powder Flat area near Blind Spring. The site was visited
seven times between 1969 and 2002 (Austin and Leary 2008, pp. 68-69).
The other six sites identified by Austin and Leary (2008, pp. 68-69)
were visited once (five of the sites) or three times (one site) between
the late 1980s and early 2000s. During a general terrestrial
invertebrate survey conducted in 2006 at 76 sites in eastern Nevada,
including 37 sites in Spring Valley (2 of which could be in or near
known locations for this subspecies), the Baking Powder Flat blue
butterfly was not encountered (Ecological Sciences, Inc. 2007, pp. 80-
82). The aerial extent of each occupied site or the host plant, or host
plant abundance, has not been reported. The Baking Powder Flat Area of
Critical Environmental Concern (ACEC) encompasses most, if not all, of
the known Baking Powder Flat blue butterfly locations. A few of the
locations may occur outside of the ACEC as all of the site descriptions
are not clear.

Biology

The Baking Powder Flat blue butterfly is associated with Eriogonum
shockleyi on which both larvae and adults are found (Austin 1993, p. 5;
Austin and Leary 2008, pp. 68-69). Larvae of this subspecies are tended
by ants (Formica obtusopilosa) (Shields 1973 cited by Austin 1993, p.
5). Pupae are likely formed in and protected by litter that is in and
beneath the host plant (Austin 1993, p. 5). Adults fly between mid and
late June (Austin 1993, p. 6; 1998c, p. 550), and there is one brood
(Austin 1993, p. 6).
There is little biological information available at the subspecies
level, but some inferences can be made from biological information from
related species at the species level. Information for the buckwheat
blue (Euphilotes battoides) indicates eggs are pale bluish-white,
turning white, and they are laid singly on the host plant's flowers
(Scott 1986, p. 403). Larvae eat flowers and fruit and are attended by
ants (Scott 1986, p. 403). No nests are constructed (Scott 1986, p.
403). Adults sip flower nectar and mud, and males patrol around the
host plant during the day seeking females (Scott 1986, p. 403).
The best available information does not include surveys documenting
this subspecies' population dynamics, nor its overall abundance, number
or size of populations, number of extirpated populations or sites, if
any, or population trends.

Five-Factor Evaluation for the Baking Powder Flat Blue Butterfly

Information pertaining to the Baking Powder Flat blue butterfly in
relation to the five factors provided in section 4(a)(1) of the Act is
discussed below.

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

Potential factors that may affect the habitat or range of the
Baking Powder Flat blue butterfly are discussed in this section,
including: (1) Water development, (2) fire, (3) livestock grazing, (4)
nonnative plant invasion, (5) agriculture, (6) recreation (off-highway
vehicles), (7) mining and energy development, (8) plant collection, and
(9) climate change.
Water Development
For general background information on water development, please
refer to the Water Development section under Factor A. The Present or
Threatened Destruction, Modification, or Curtailment of Its Habitat or
Range in the Five-Factor Evaluation for the White River Valley Skipper.
The NNHP (2007, p. 42) estimates that about 30 percent of the
Baking Powder Flat playa/ephemeral pool/spring pool complex has been
degraded or converted to other land uses, including by water
development. The NNHP (2007) does not delineate this area on a map or
define it in terms of acreage; therefore, the amount of Baking Powder
Flat blue butterfly habitat that may occur within this area and may be
impacted by various land use practices, if any, is not documented.
However, it is important to note that the Baking Powder Flat blue
butterfly's host plant occurs in dry areas and not within wetland
areas. The extent to which the various land use practices have degraded
or converted this area is also not individually delineated or
quantified by NNHP (2007).
Concerns have been raised regarding SNWA's proposed water
development project and its potential impacts to the Baking Powder Flat
area and the Baking Powder Flat ACEC (Charlet 2006, p. 19; BLM 2009a,
pp. 20-21). During ROWs surveys for various facilities associated with
the SNWA project (i.e., powerlines, pipelines), the Baking Powder Flat
blue butterfly was not observed (BLM 2011a, pp. 3.6-19; 3.14-4), but
all facility locations have not yet been determined (BLM 2011a, p. 2-
5). The butterfly has been recorded from Spring Valley within the
proposed groundwater development area within the ACEC (BLM 2011a, pp.
3.6-22; 3.14-4); this location is in reference to the site near Blind
Spring. The Baking Powder Flat blue butterfly and its habitat could be
impacted during construction and facility maintenance activities by
direct mortality resulting from construction or vehicles, disruption of
breeding success, temporary or permanent loss of habitat, and habitat
fragmentation (BLM 2011a, p. 3.6-70). However, BLM mitigation
recommendation GW-WL-6 has been included in the proposed project (BLM
2011a, p. 3.6-70). This mitigation recommendation involves pre-
construction surveys and the avoidance of Baking Powder Flat blue
butterfly occurrence sites and habitat during facility siting to the
extent practicable (BLM 2011a, p. 3.6-71). Because the ACEC is large
(13,640 ac (5,520 ha)) (72 FR 67748, November 30, 2007), any

[[Page 54317]]

facilities constructed, if approved, would impact a small percentage of
the ACEC's area. This is in addition to the restoration requirements
provided for in the BLM's Ely RMP (BLM 2011a, p. 3.6-70) and BLM's
determination for the Baking Powder Flat ACEC that an issuance of a ROW
permit will result in minimal conflict with identified resource values
and that impacts can be mitigated.
In addition to possible construction impacts, the groundwater flow
model estimate for 200 years post full buildout (BLM 2011a, p. 3.3-102)
shows Blind Spring within the project's greater than 10-foot (3.0-m)
drawdown contour. Blind Spring is located in the ACEC and within 1 mi
(1.6 km) of some Baking Powder Flat blue butterfly observations (Austin
and Leary 2008, pp. 68-69). As stated earlier, the host plant,
described as common in Baking Powder Flat (BLM 2009a, p. 20), grows on
relatively hard and bare areas between sand dunes (Austin 1998c, p.
550) and mostly on gravelly, clayey, or sandy soils, or on rocky
outcrops and ledges in association with upland plants (Kartesz 1987, p.
282); it is not a wetland-dependent species. Therefore, it is unlikely
SNWA's proposed water development project will indirectly impact the
Baking Powder Flat blue butterfly in Spring Valley through groundwater
drawdowns. The Baking Powder Flat blue butterfly habitat is not
specifically considered in the Spring Valley Stipulation because the
subspecies and its habitat are not considered to be at risk from
groundwater development (SNWA, in litt. 2011, p. 36).
Because the Baking Powder Flat blue butterfly's host plant grows in
dry areas and not within the Baking Powder Flat wetland areas, it is
unlikely that current groundwater rights or SNWA's proposed water
development project which have been and are considered under Nevada
water law will indirectly impact the butterfly through groundwater
drawdowns. The host plant is considered common in the Baking Powder
Flat area, and the butterfly has been documented in several areas in
the ACEC, and possibly outside it as some butterfly location
descriptions are unclear. Any facilities constructed in the ACEC would
impact a small percentage (unknown at this time) of the ACEC's total
area and would be mitigated by SNWA project mitigations or BLM
requirements. At this time, the best available information does not
indicate that water development is modifying the subspecies' habitat or
that its habitat may be modified through SNWA's proposed project to the
extent that it represents a threat to this subspecies now or in the
future.
Fire
Butterflies have specialized habitat requirements (Thomas 1984, p.
337). Changes in the structure and composition of vegetation due to
natural or other means can threaten butterfly populations as these
changes can disrupt specific habitat requirements (Thomas 1984, pp.
337-341). The effects of fire on the landscape depend on the
composition of plant species present, and the size, frequency, and
intensity of fire. Burning can also allow invasive species, such as
Bromus tectorum, to increase (Stewart and Hull 1949 and Wright and
Britton 1976, cited in Yensen 1982, p. 28).
Fleischman (2000, pp. 688-689) found that a prescribed fire in a
watershed in Nevada did not appear to affect butterfly species richness
or composition between burned areas and their paired controls. Vogel et
al. (2007, p. 78) evaluated three restoration practices in prairie
habitat on butterfly communities and found that the total butterfly
abundance was highest in areas restored through burning and grazing,
and was lowest in areas that were only burned. Species richness did not
differ among the practices. Species diversity was highest in areas that
were only burned. Individual butterfly species responses to the
restoration practices were variable.
The petition mentions fire as a potential threat to the Baking
Powder Flat blue butterfly (Bruce Boyd, pers. comm. cited in Wild Earth
Guardians 2010, p. 14) though it does not provide specific information
to support this claim. Fires have occurred in many areas of Nevada over
the years and will occur in the future. The best available information
does not indicate that fire has occurred in areas that are occupied by
the Baking Powder Flat blue butterfly (Podborny 2012, pers. comm.). The
Baking Powder Flat area occurs in a valley bottom with sandy soils and
widespread vegetation, thus the amount and distribution of vegetation
needed to support a fire through this area are not available (Podborny
2012, pers. comm.). In addition, the host plant, Eriogonum shockleyi,
remains common in the Baking Powder Flat area (BLM 2009a, p. 20).
Actions regarding fire management within Baking Powder Flat blue
butterfly habitat would be addressed in consideration of the Ely
District Record of Decision and Approved RMP (BLM 2008a), BLM's 6840
Manual (BLM 2008b) (see our discussion of these authorities in the
analysis of the White River Valley skipper), the Emergency
Stabilization and Burned Area Rehabilitation Program, Baking Powder
Flat ACEC restrictions, and possibly NEPA. We did not receive any
information as a result our 90-day petition finding notice, nor did we
locate information indicating that fire is impacting the habitat or
populations of the Baking Powder Flat blue butterfly. Consequently, the
best available information does not indicate that fire is modifying the
subspecies' habitat to the extent that it is a threat to this
subspecies now or in the future.
Livestock Grazing
For general background information on livestock grazing, please
refer to the Livestock Grazing section under Factor A. The Present or
Threatened Destruction, Modification, or Curtailment of Its Habitat or
Range in the Five-Factor Evaluation for the White River Valley Skipper.
The NNHP (2007, p. 42) indicates that a portion of the Baking
Powder Flat playa/ephemeral pool/spring pool complex has been degraded
or converted to other land uses, including livestock grazing. The
petition indicates that livestock will graze Eriogonum shockleyi
(WildEarth Guardians 2010, p. 13), but disturbance to this host plant
from trampling and soil compaction from livestock was mentioned in the
petition and by others as a greater potential threat (Austin 1993, p.
7; Austin et al., in litt. 2000, p. 3; NatureServe 2009c, p. 2; B.
Boyd, pers. comm. cited in WildEarth 2010, p. 13), though specific
information to support this concern is not provided. Injury to or loss
of host plant populations would negatively impact larvae and adults as
both life stages utilize this plant for food and shelter. Livestock
grazing is occurring over widespread general habitat areas where the
Baking Powder Flat blue butterfly is either known to occur or could be
occurring. In the early 1990s, there were reports of grazing at the
site near Blind Spring; in 1992, heavy cattle grazing and trampling was
reported (Barber, in litt. 1992b, p. 1), while 2 years later, in 1994,
light use and minimal trampling by cattle was noted at this one site
(Barber, in litt. 1994, p. 1). Currently, grazing is authorized within
the Baking Powder Flat ACEC and is controlled through grazing permit
terms and conditions (BLM 2007c, pp. 2.4-101; 2.4-106). BLM has
indicated that some (undefined) areas of the ACEC can be ``heavily
impacted'' by livestock grazing (BLM 2009a, p. 21). Over 70 percent of
the ACEC is within the South Spring Valley Allotment (SNWA, in litt.
2011, p. 37).

[[Page 54318]]

However, the host plant is not known to be heavily grazed upon or
preferred by livestock within the ACEC (Podborny 2012, pers. comm.).
While livestock can and do move through the ACEC, concentrations in the
butterfly's habitat do not occur as water is not readily available to
them (Podborny 2012, pers. comm.). Thus, trampling of the host plant by
livestock is not likely. The best available information indicates that
the host plant, Eriogonum shockleyi, remains common in the Baking
Powder Flat area (BLM 2009a, p. 20), and injury to or declines in the
host plant species, larvae, or adults due to livestock grazing
practices have not been documented. Activities involving grazing
management within the Baking Powder Flat blue butterfly habitat would
be addressed in consideration of the Ely District Record of Decision
and Approved RMP (BLM 2008a), BLM's authority under Regulations on
Grazing Administration Exclusive of Alaska, BLM's 6840 Manual (BLM
2008b), Baking Powder Flat ACEC restrictions, and possibly NEPA (see
our discussion of these authorities in the above analysis for the White
River Valley skipper and below, with respect to the Baking Power Flat
ACEC). We did not receive any information as a result of our 90-day
petition finding notice, nor did we locate information indicating that
livestock grazing is negatively impacting the habitat or populations of
the Baking Powder Flat blue butterfly. Thus, the best available
information does not indicate that livestock grazing is modifying the
subspecies' habitat to the extent that it represents a threat to this
subspecies now or in the future.
Nonnative Plant Invasion
For general background information on nonnative plant invasion,
please refer to the Nonnative Plant Invasion section under Factor A.
The Present or Threatened Destruction, Modification, or Curtailment of
Its Habitat or Range in the Five-Factor Evaluation for the White River
Valley Skipper.
The NNHP (2007, p. 42) indicates that a portion of the Baking
Powder Flat playa/ephemeral pool/spring pool complex has been degraded,
including by nonnative species invasion. The petition states that
nonnative plant species invasion may be a potential threat to the
Baking Powder Flat blue butterfly (B. Boyd, pers. comm. cited by
WildEarth 2010, p. 14) though specific information to support this
claim is not provided. Because numerous nonnative and invasive plant
species occur in Nevada, it is likely that nonnative and invasive plant
species occur to some extent, though this has not been quantified,
within the ACEC and the habitat of the Baking Powder Flat blue
butterfly. However, the issue of nonnative plant species invasion is
not known to be a concern in the ACEC (Podborny 2012, pers. comm.).
Though the Baking Powder Flat blue butterfly is associated with only
one plant species for its life-history requirements, nonnative plant
species do not appear to be competing with it and causing it to
decline, as the host plant remains common in the Baking Powder Flat
area and ACEC.
Activities involving nonnative plant species management within the
Baking Powder Flat blue butterfly habitat would be addressed in
consideration of the Ely District Record of Decision and Approved RMP
(BLM 2008a), BLM's authority under Regulations on Grazing
Administration Exclusive of Alaska, the Plant Protection Act of 2000,
BLM's programmatic EIS for vegetation treatments on BLM's administered
lands in the western United States (BLM 2007a), BLM's 6840 Manual (BLM
2008b), Baking Powder Flat ACEC restrictions, and possibly NEPA (see
our discussion of these authorities above in the analysis of the White
River Valley skipper, and below with respect to the Baking Power Flat
ACEC). We did not receive any information as a result of our 90-day
petition finding notice, nor did we locate information indicating that
nonnative or invasive plant species are negatively impacting occupied
habitat or populations of the Baking Powder Flat blue butterfly.
Therefore, the best available information does not indicate that
nonnative plant species are modifying the subspecies' habitat to the
extent that it represents a threat to this subspecies now or in the
future.
Agriculture
The NNHP (2007, p. 42) indicates that a portion of the Baking
Powder Flat playa/ephemeral pool/spring pool complex has been degraded
or converted to other land uses, including agriculture. Although
impacts of agriculture were mentioned in the petition as a potential
threat to the Baking Powder Flat blue butterfly (WildEarth Guardians
2010, p. 13), information was not provided to support this claim.
Agriculture does not occur in the ACEC (Podborny 2012, pers. comm.).
The best available information does not indicate agriculture is
occurring in areas occupied by the Baking Powder Flat blue butterfly.
We did not receive any information as a result of our 90-day petition
finding notice, nor did we locate information that indicates
agriculture is impacting occupied habitat or populations of the Baking
Powder Flat blue butterfly. Thus, the best available information does
not indicate that agriculture is modifying this subspecies' habitat to
the extent that it represents a threat to Baking Powder Flat blue
butterfly populations, their host plants, or nectar sources, now or in
the future.
Recreation (Off-Highway Vehicles)
Off-highway vehicle (OHV) impacts on wildlife can include habitat
loss and fragmentation, patch size reduction, and an increase in the
ratio of edge to the interior (U.S. Geological Survey (USGS) 2007, p.
16). These effects can influence population dynamics, predator-prey
relationships, and animal movements (e.g., dispersal, recolonization,
gene flow). Even narrow roads and trails can create a barrier to animal
movements. Additionally, OHV roads can facilitate range extensions or
invasions of nonnative and opportunistic species, direct mortality
through collisions, and nest and burrow damage or destruction, and they
create noise. These factors can lead ultimately to reduced survivorship
of a species.
One study involving butterflies found wide highways did not affect
movement with open populations (immigration and emigration continues to
occur), but did slightly impact those with closed populations (Munguira
and Thomas 1992, cited in USGS 2007, p. 18). Another study found some
butterfly species may not attempt to fly across roads possibly due to
the microclimate over roads (van der Zande 1980, cited in USGS 2007, p.
18).
In 2008, BLM designated a portion of Baking Powder Flat (13,640
acres (ac)) (5,520 hectares (ha)) as the Baking Powder Flat ACEC to
protect the Baking Powder Flat blue butterfly (72 FR 67748; 73 FR
55867, September 26, 2008; BLM 2009a, p. 20). According to BLM (2009b,
p. 20), an ACEC is defined as an area ``within the public lands where
special management attention is required (when such areas are developed
or used or where no development is required) to protect and prevent
irreparable damage to important historic, cultural, or scenic values,
fish and wildlife resources, or other natural systems or processes, or
to protect life and safety from natural hazards.'' The Baking Powder
Flat ACEC is managed as an ``avoidance area [* * *.] [G]ranting rights-
of-way (surface, subsurface, aerial) within the area will be avoided,
but rights-of-way may be granted if there is minimal conflict with
identified resource values and impacts can be mitigated.''
Limited OHV use is authorized within the Baking Powder Flat ACEC on

[[Page 54319]]

designated roads and trails (72 FR 67748; BLM 2007c, pp. 2.4-101, 2.4-
106). Austin (1993, p. 7) and Austin et al. (in litt. 2000, p. 3)
indicate that soil compaction or direct destruction of host plants from
vehicles may impact the Baking Powder Flat blue butterfly, however, no
additional information was provided to support this claim. A site visit
to the occupied location near Blind Spring found evidence of one
motorcycle going through the area as reported by a BLM employee in 1994
(Barber in litt. 1994, p. 1). Today, with use limited to designated
roads and trails, this recreational activity is not considered a
concern in the ACEC (Podborny 2012, pers. comm.). Activities involving
OHV use within the Baking Powder Flat blue butterfly habitat would be
addressed in consideration of the Ely District Record of Decision and
Approved RMP (BLM 2008a), BLM's 6840 Manual (BLM 2008b), Baking Powder
Flat ACEC restrictions, and possibly NEPA (see also our discussion of
several of these authorities in our analysis of the White River Valley
skipper, above). We did not receive additional information as a result
of our 90-day petition finding notice, nor did we locate information
indicating that OHV use is damaging this subspecies' habitat.
Consequently, the best available information does not indicate that OHV
use is modifying this subspecies' habitat to the extent that it
represents a threat to Baking Powder Flat blue butterfly populations or
their habitats now or in the future.
Mining and Energy Exploration and Development, Power Lines
The NNHP (2007, p. 42) indicates that a portion of the Baking
Powder Flat playa/ephemeral pool/spring pool complex has been degraded
or converted to other land uses, including energy development. Baking
Powder Flat blue butterfly habitat was not identified within the study
area for Southwest Intertie Project (BLM 1993, p. 3-65). The Baking
Powder Flat blue butterfly was also not observed during wildlife
surveys conducted for the One Nevada Transmission Line Project (BLM
2010c, Appendix 3D, Table 2, pp. 1-5).
There are closures or limits on mineral development within the
Baking Powder Flat ACEC to protect the unique cultural values, and
special status plants and animals, which includes the Baking Powder
Flat blue butterfly (72 FR 67748; BLM 2007c, p. 2.4-101), and these
types of projects are not occurring in the ACEC (Podborny 2012, pers.
comm.). Additionally, actions involving mineral and energy development
within Baking Powder Flat blue butterfly habitat would be addressed in
consideration of the Ely District Record of Decision and Approved RMP
(BLM 2008a), the FLPMA of 1976, the Mineral Leasing Act of 1920, BLM's
6840 Manual (BLM 2008b), and NEPA (see our discussion of these
authorities above in our analysis of the White River Valley skipper).
The available information does not indicate that mineral and energy
development are occurring in areas occupied by the Baking Powder Flat
blue butterfly. We did not receive additional information as a result
of our 90-day petition finding notice, nor did we locate information
that indicates mining or energy development, or transmission line
installation is impacting the Baking Powder Flat blue butterfly
habitat. Thus, the best available information does not indicate that
mining and energy development are modifying the subspecies' habitat or
impacting Baking Powder Flat blue butterfly populations to an extent
that they represent a threat to this subspecies now or in the future.
Plant Collection
Plant collecting is authorized within the Baking Powder Flat ACEC
(72 FR 67748; BLM 2007c, p. 2.4-101). Plant materials, including common
species, require a permit to be collected (BLM 2007c, pp. 2.4-101; 2.4-
106). There have been no permit requests for collection of the host
plant, Eriogonum shockleyi, for any purpose (Podborny 2012, pers.
comm.). As indicated earlier, this host plant remains common in the
Baking Powder Flat area (BLM 2009a, p. 20), and declines in this plant
species have not been documented. Actions involving plant collection
within Baking Powder Flat blue butterfly habitat would be addressed in
consideration of the Ely District Record of Decision and Approved RMP
(BLM 2008a), BLM's 6840 Manual (BLM 2008b), the Baking Powder Flat
ACEC, and possibly the Plant Protection Act of 2000 and NEPA (see our
discussion of these authorities above in the analysis of the White
River Valley skipper). We did not receive any information as a result
of our 90-day petition finding notice, nor did we locate information
that indicates plant collecting in the ACEC, specifically for the host
plant or in general, is occurring in occupied Baking Powder Flat blue
butterfly habitat. Therefore, the best available information does not
indicate that plant collecting is modifying the subspecies' habitat to
an extent that it represents a threat to this subspecies now or in the
future.
Climate Change
Recent projections of climate change in the Great Basin over the
next century include: Increased temperatures, with an increased
frequency of extremely hot days in summer; more variable weather
patterns and more severe storms; more winter precipitation in the form
of rain, with potentially little change or decreases in summer
precipitation; and earlier, more rapid snowmelt (U.S. Environmental
Protection Agency 1998, pp. 1-4; Chambers and Pellant 2008, pp. 29-33).
While the petition asserts that climate change may impact this
subspecies (WildEarth Guardians 2010, p. 40), it is difficult to
predict local climate change impacts, due to substantial uncertainty in
trends of hydrological variables, limitations in spatial and temporal
coverage of monitoring networks, and differences in the spatial scales
of global climate models and hydrological models (Bates et al. 2008, p.
3).
We found no information on how climate change may impact the Baking
Powder Flat blue butterfly's host plant, Eriogonum shockleyi. In
general, increasing temperatures and drought frequency could impact the
host plant by causing physiological stress, altering phenology,
reducing recruitment events, and reducing seed establishment. However,
at this time, it is difficult to predict local climate change impacts
to Eriogonum Shockleyi and how individual plant species will react to
climate change, especially for a species which grows in dry, warm sites
and thus has adaptations for such conditions.
Thus, while information indicates that climate change has the
potential to affect vegetation and habitats used by the Baking Powder
Flat blue butterfly in the Great Basin, there is much uncertainty
regarding which habitat attributes could be affected, and the timing,
magnitude, and rate of their change as it relates to this subspecies.
The available information does not indicate that climate change is
affecting occupied Baking Powder Flat blue butterfly habitat. We did
not receive any further information as a result of our 90-day petition
finding notice, nor did we locate specific information that indicates
climate change is impacting Baking Powder Flat blue butterfly
populations or their habitats. Thus, the best available information
does not indicate that climate change is modifying the subspecies'
habitat to an extent that it represents a threat to this subspecies now
or in the future.
Summary of Factor A
While several activities such as water development, fire, livestock
grazing, nonnative species invasion, agriculture, mining and energy
development may be

[[Page 54320]]

impacting a portion of the Baking Powder Flat wetland complex according
to NNHP (2007 p. 42), available information does not indicate that
these impacts are occurring in and negatively impacting occupied Baking
Powder Flat blue butterfly habitat, which occurs outside of wetland
areas. The available information does not indicate that these
activities, or additional activities such as OHV use, plant collecting,
or climate change, are negatively impacting Baking Powder Flat blue
butterfly habitat or populations. The subspecies' larval host plant and
adult nectar source (Eriogonum shockleyi) does not occur in wetland
areas and is unlikely to be indirectly impacted by current or proposed
water development activities. The host plant remains common in the
Baking Powder Flat area (BLM 2009a, p. 20). In addition to the larval
host plant not being a wetland species, any direct impacts to the plant
through proposed SNWA water development facility construction
activities, if approved, should be minor due to the commitment to
implement avoidance, reduction, and mitigation measures. While
information indicates that climate change has the potential to affect
vegetation used by this subspecies, much uncertainty remains regarding
which plant attributes may be affected, and the timing, magnitude, and
rate of their change. We conclude based on the best scientific and
commercial information available that the present or threatened
destruction, modification, or curtailment of its habitat or range does
not currently pose a threat to the Baking Powder Flat blue butterfly,
nor is it likely to become a threat to the subspecies in the future.

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

We are unaware of any studies analyzing impacts of removal of
individuals from populations of the Baking Powder Flat blue butterfly.
According to Austin (1998c, p. 550), 61 males and 41 females of this
subspecies were collected between 1978 and 1980 at one site. No
additional information is known about the numbers of specimens
collected in the past, and we are not aware of any ongoing or current
collecting of this subspecies. Given the relatively low number of
individuals collected over this 3-year period, the length of time since
the collections were made, and the lack of information about the
relative impact to the population, the available information does not
indicate that collection may be a threat to this subspecies.
We found no information indicating that overutilization has led to
the loss of populations or a significant reduction in numbers of
individuals for this subspecies. Therefore, we conclude based on the
best scientific and commercial information available that
overutilization for commercial, recreational, scientific, or
educational purposes does not currently pose a threat to the Baking
Powder Flat blue butterfly, nor is it likely to become a threat to the
subspecies in the future.

Factor C. Disease or Predation

We found no information on the incidence of disease in the Baking
Powder Flat blue butterfly.
Predation by other species, such as birds or insects, on eggs,
larvae, pupae, or adult Baking Powder Flat blue butterflies is assumed,
but we found no information indicating that predation levels are any
greater than naturally occurring levels typical of the biological
community in which the Baking Powder Flat blue butterfly occurs.
Available information does not indicate that there are impacts from
disease or predation on the Baking Powder Flat blue butterfly.
Therefore, we conclude based on the best scientific and commercial
information available that disease or predation does not currently pose
a threat to the Baking Powder Flat blue butterfly, nor is either likely
to become a threat to the subspecies in the future.

Factor D. The Inadequacy of Existing Regulatory Mechanisms

The discussion of existing regulatory mechanisms under Factor D for
the White River Valley skipper is hereby incorporated into this
discussion for the Baking Power Flat blue butterfly. As discussed above
under Factor D for the White River Valley skipper, Nevada State law
pertaining to wildlife does not offer protection to the Baking Powder
Flat blue butterfly specifically because it is an invertebrate species
not classified as wildlife. Although not protected by State wildlife
law, the best available information, as discussed in Factor B, does not
indicate that collection or other forms of overutilization is a threat
to the Baking Powder Flat blue butterfly.
A large portion of habitat for the Baking Powder Flat blue
butterfly occurs on Federal lands administered by BLM. Numerous
policies, guidance, and laws have been developed to assist the agency
in management of these lands (see Factor D discussion under White River
Valley skipper). BLM policies and guidance address species of concern,
actions covered by RMPs, and regulatory authority for grazing and oil
and gas leasing and operating activities. As discussed under Factor A,
the best available information does not indicate that activities such
as livestock grazing, nonnative plant control, mining and energy
exploration and development, and recreational activities that are
regulated by various policies, guidance, and laws on Federal lands are
impacting Baking Powder Flat blue butterfly populations. After
reviewing the best available commercial and scientific information, we
conclude that the inadequacy of existing regulatory mechanisms does not
currently pose a threat to the Baking Powder Flat blue butterfly, nor
is it likely to become a threat to the subspecies in the future.

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

Potential other natural or manmade factors that may affect the
continued existence of the Baking Powder Flat blue butterfly are
discussed in this section and include: (1) Limited range and (2) small
population size(s).
For general background information on other natural or manmade
factors which could affect the Baking Powder Flat blue butterfly,
please refer to the discussion on limited range and population size
under Factor E. Other Natural or Manmade Factors Affecting Its
Continued Existence in the Five-Factor Evaluation for the White River
Valley Skipper.
The Baking Powder Flat blue butterfly is known from seven discrete
areas in the Baking Powder Flat area in Spring Valley, in Lincoln and
White Pine Counties, Nevada (Austin 1998c, p. 550; Austin and Leary
2008, pp. 68-69). As indicated earlier, the host plant species,
Eriogonum shockleyi, is common in Nevada and occurs in several other
states. For the Baking Powder Flat blue butterfly, little information
is available related to its distribution and numbers of populations,
and no information is available about size of populations, loss of
populations, if any, or population trends. Information pertaining to
the aerial extent of habitat or populations is also not available.
Available information does not include comprehensive surveys for this
subspecies, though researchers have recommended these surveys to
determine if additional populations exist. Without data to indicate
population trends, it is difficult to support claims of adverse impacts
to the Baking Powder Flat blue butterfly.
We found no information on connections between chance events and
population impacts for the Baking Powder Flat blue butterfly. This
subspecies is distributed over several

[[Page 54321]]

areas in the Baking Powder Flat area, and as mentioned above,
recommendations have been made for surveys to determine if it is more
widespread than currently known. Potential impacts due to stochastic
events are reduced because it occurs in several areas. In the absence
of chance events connected to known populations, we do not consider
restricted geographic range or small population numbers by themselves
to be threats to this subspecies. The best available information does
not indicate the Baking Powder Flat blue butterfly is negatively
impacted by limited range or small population numbers. Therefore, we
conclude based on the best available scientific and commercial
information that other natural or manmade factors do not currently pose
a threat to the Baking Powder Flat blue butterfly, nor are they likely
to become a threat to the subspecies in the future.

Synergistic Interactions Between Threat Factors

We have evaluated individual threats to the Baking Powder Flat blue
butterfly. This subspecies faces potential threats from water
development, fire, livestock grazing, nonnative plant invasion,
agriculture, OHV use, mining and energy development, plant collection,
climate change, limited range, and small population size. In
considering whether the threats to a species may be so great as to
warrant listing under the Act, we must look beyond the possible impacts
of potential threats in isolation and consider the potential cumulative
impacts of all of the threats facing a species.
In making this finding, we considered whether there may be
cumulative effects to the Baking Powder Flat blue butterfly from the
combined impacts of the existing stressors such that even if each
stressor individually does not result in population-level impacts, that
cumulatively the effects may be significant. We considered whether the
combined effects of water development and mining and energy development
may result in a significant impact to the Baking Powder Flat blue
butterfly because these potential impacts have the potential to result
in some level of habitat loss. However, we conclude that synergistic
effects between water development and mining and energy development are
unlikely to result in a significant overall population impact to the
Baking Powder Flat blue butterfly because the proposed water
development construction footprint would be small, indirect impacts
from the water development project are not likely, and BLM policies and
mitigation measures ensure that impacts to this subspecies' habitat in
the Baking Powder Flat ACEC will be minimized.
Mining and energy development were not found to occur in the
butterfly's habitat. If mining and energy development projects are
proposed in the future, BLM policies and management offer protection
through limitations for these types of activities within the ACEC.
Livestock grazing, nonnative plant invasion, and OHV use could impact
the Baking Powder Flat blue butterfly and its habitat. However, BLM
policies and management provide terms and conditions for livestock
grazing to protect resources; nonnative plant species invasion is not
known to be a concern in the ACEC; and OHV use is limited to existing
roads and trails in the ACEC.
Therefore, we conclude that livestock grazing, nonnative plant
species invasion, and OHV use impacts combined with potential impacts
from water development and mining and energy development would not be
of sufficient severity, frequency, or geographic scope to result in
significant habitat impacts or cause population-level impacts to the
Baking Powder Flat blue butterfly. Fire is unlikely to occur in Baking
Powder Flat blue butterfly habitat due to the sandy soils and widely
spaced vegetation being unable to support a fire. Agriculture and
collection of the host plant species were not found to occur within
this subspecies habitat and, therefore, will not have a cumulative
impact on the Baking Powder Flat blue butterfly.
Limited range and small population size could make the Baking
Powder Flat blue butterfly more vulnerable to potential threats
discussed above. However, we cannot conclude that synergistic effects
between limited range and small population size and other potential
threats are operative threats to the continued existence of the Baking
Powder Flat blue butterfly given the lack of information on the range
and population size of this butterfly. There is no information on
population size or change in population abundance for the Baking Powder
Flat blue butterfly, and the limited information on occurrence
(distribution) is insufficient to define this butterfly's range.
Synergistic interactions are possible between effects of climate
change and effects of other stressors such as livestock grazing,
nonnative plant invasion, and OHV use. Increases in carbon dioxide and
temperature and changes in precipitation are likely to affect
vegetation, and the Baking Powder Flat blue butterfly is closely
associated with the presence of certain types of vegetation. However,
it is difficult to project how climate change will affect vegetation
because certain plant species may increase in cover while other species
may decrease. Uncertainty about how different plant species will
respond under climate change, combined with uncertainty about how
changes in plant species composition would affect suitability of Baking
Powder Flat blue butterfly habitat, make projecting possible
synergistic effects of climate change on the Baking Powder Flat blue
butterfly too speculative.

Finding for the Baking Powder Flat Blue Butterfly

As required by the Act, we considered the five factors in assessing
whether the Baking Powder Flat blue butterfly is an endangered or
threatened species throughout all of its range. We examined the best
scientific and commercial information available regarding the past,
present, and future threats faced by this subspecies.
Factors potentially affecting the Baking Powder Flat blue
butterfly, including water development, fire, livestock grazing,
nonnative species invasion, agriculture, mining and energy development,
OHV, plant collecting, climate change, and limited range and small
population size, are either limited in scope or lack documentation that
they are occurring in occupied habitat and adversely impacting the
subspecies. Though climate change may be affecting the Baking Powder
Flat blue butterfly and its habitat and effects are likely to increase
in the future, the available information does not support a
determination that climate change has or will result in a population-
level impact to this subspecies. The available information does not
indicate that overutilization, disease, or predation is a threat to the
Baking Powder Flat blue butterfly. The available information also does
not indicate that existing regulatory mechanisms are inadequate to
protect the subspecies from potential threats. Furthermore, there is no
evidence to suggest that the combined factors acting together are a
threat to the Baking Powder Flat blue butterfly. Based on our review of
the best scientific and commercial information available, we find these
stressors, either singly or in combination with one another, are not
threats to the Baking Powder Flat blue butterfly or its habitat.
We found no information to indicate that threats are of sufficient
imminence, intensity, or magnitude such that the Baking Powder Flat
blue butterfly is in danger of extinction (endangered) or likely to
become endangered within the

[[Page 54322]]

foreseeable future (threatened), throughout all of its range.
Therefore, we find that listing the Baking Powder Flat blue butterfly
as an endangered or threatened species throughout its range is not
warranted.

Significant Portion of the Range

Having determined that the Baking Powder Flat blue butterfly does
not meet the definition of an endangered or a threatened species, we
must next consider whether there are any significant portions of the
range where the Baking Powder Flat blue butterfly is in danger of
extinction or is likely to become endangered in the foreseeable future.
The Act defines ``endangered species'' as any species which is ``in
danger of extinction throughout all or a significant portion of its
range,'' and ``threatened species'' as any species which is ``likely to
become an endangered species within the foreseeable future throughout
all or a significant portion of its range.'' 16 U.S.C. 1532(6) and
1532(20). The definition of ``species'' is also relevant to this
discussion. The Act defines ``species'' as follows: ``The term
`species' includes any subspecies of fish or wildlife or plants, and
any distinct population segment of any species of vertebrate fish or
wildlife which interbreeds when mature.'' 16 U.S.C. 1532(16). The
phrase ``significant portion of its range'' (SPR) is not defined by the
statute, and we have never addressed in our regulations: (1) The
consequences of a determination that a species is either endangered or
likely to become so throughout a significant portion of its range, but
not throughout all of its range; or (2) what qualifies a portion of a
range as ``significant.''
Two recent district court decisions have addressed whether the SPR
language allows the Service to list or protect less than all members of
a defined ``species'': Defenders of Wildlife v. Salazar, 729 F. Supp.
2d 1207 (D. Mont. 2010), concerning the Service's delisting of the
Northern Rocky Mountains gray wolf (74 FR 15123, April 2, 2009); and
WildEarth Guardians v. Salazar, 2010 U.S. Dist. LEXIS 105253 (D. Ariz.
September 30, 2010), concerning the Service's 2008 finding on a
petition to list the Gunnison's prairie dog (73 FR 6660, February 5,
2008). The Service had asserted in both of these determinations that,
under the Act, it had authority, in effect, to protect only some
members of a ``species,'' as defined by the Act (i.e., species,
subspecies, or DPS). Both courts ruled that the determinations were
arbitrary and capricious on the grounds that this approach violated the
plain and unambiguous language of the Act. The courts concluded that
reading the SPR language to allow protecting only a portion of a
species' range is inconsistent with the Act's definition of
``species.'' The courts concluded that once a determination is made
that a species (i.e., species, subspecies, or DPS) meets the definition
of ``endangered species'' or ``threatened species,'' it must be placed
on the list in its entirety and the Act's protections applied
consistently to all members of that species throughout its range
(subject to modification of protections through special rules under
sections 4(d) and 10(j) of the Act).
Consistent with that interpretation, and for the purposes of this
finding, we interpret the phrase ``significant portion of its range''
in the Act's definitions of ``endangered species'' and ``threatened
species'' to provide an independent basis for listing. Thus there are
two situations (or factual bases) under which a species would qualify
for listing: A species may be endangered or threatened throughout all
of its range, or a species may be endangered or threatened in only a
significant portion of its range. If a species is in danger of
extinction throughout an SPR, it, the species, is an ``endangered
species.'' The same analysis applies to ``threatened species.'' Based
on this interpretation and supported by existing case law, the
consequence of finding that a species is endangered or threatened in
only a significant portion of its range is that the entire species
shall be listed as endangered or threatened, respectively, and the
Act's protections shall be applied across the species' entire range.
We conclude, for the purposes of this finding, that interpreting
the SPR phrase as providing an independent basis for listing is the
best interpretation of the Act because it is consistent with the
purposes and the plain meaning of the key definitions of the Act; it
does not conflict with established past agency practice (i.e., prior to
the 2007 Solicitor's Opinion), as no consistent, long-term agency
practice has been established; and it is consistent with the judicial
opinions that have most closely examined this issue. Having concluded
that the phrase ``significant portion of its range'' provides an
independent basis for listing and protecting the entire species, we
next turn to the meaning of ``significant'' to determine the threshold
for when such an independent basis for listing exists.
Although there are potentially many ways to determine whether a
portion of a species' range is ``significant,'' we conclude, for the
purposes of this finding, that the significance of the portion of the
range should be determined based on its biological contribution to the
conservation of the species. For this reason, we describe the threshold
for ``significant'' in terms of an increase in the risk of extinction
for the species. We conclude that a biologically based definition of
``significant'' best conforms to the purposes of the Act, is consistent
with judicial interpretations, and best ensures species' conservation.
Thus, for the purposes of this finding, and as explained further below,
a portion of the range of a species is ``significant'' if its
contribution to the viability of the species is so important that,
without that portion, the species would be in danger of extinction.
We evaluate biological significance based on the principles of
conservation biology using the concepts of redundancy, resiliency, and
representation. Resiliency describes the characteristics of a species
and its habitat that allow it to recover from periodic disturbance.
Redundancy (having multiple populations distributed across the
landscape) may be needed to provide a margin of safety for the species
to withstand catastrophic events. Representation (the range of
variation found in a species) ensures that the species' adaptive
capabilities are conserved. Redundancy, resiliency, and representation
are not independent of each other, and some characteristic of a species
or area may contribute to all three. For example, distribution across a
wide variety of habitat types is an indicator of representation, but it
may also indicate a broad geographic distribution contributing to
redundancy (decreasing the chance that any one event affects the entire
species), and the likelihood that some habitat types are less
susceptible to certain threats, contributing to resiliency (the ability
of the species to recover from disturbance). None of these concepts is
intended to be mutually exclusive, and a portion of a species' range
may be determined to be ``significant'' due to its contributions under
any one or more of these concepts.
For the purposes of this finding, we determine if a portion's
biological contribution is so important that the portion qualifies as
``significant'' by asking whether, without that portion, the
representation, redundancy, or resiliency of the species would be so
impaired that the species would have an increased vulnerability to
threats to the point that the overall species would be in danger of
extinction (i.e., would be ``endangered''). Conversely, we would

[[Page 54323]]

not consider the portion of the range at issue to be ``significant'' if
there is sufficient resiliency, redundancy, and representation
elsewhere in the species' range that the species would not be in danger
of extinction throughout its range if the population in that portion of
the range in question became extirpated (extinct locally).
We recognize that this definition of ``significant'' (a portion of
the range of a species is ``significant'' if its contribution to the
viability of the species is so important that, without that portion,
the species would be in danger of extinction) establishes a threshold
that is relatively high. On the one hand, given that the consequences
of finding a species to be endangered or threatened in an SPR would be
listing the species throughout its entire range, it is important to use
a threshold for ``significant'' that is robust. It would not be
meaningful or appropriate to establish a very low threshold whereby a
portion of the range can be considered ``significant'' even if only a
negligible increase in extinction risk would result from its loss.
Because nearly any portion of a species' range can be said to
contribute some increment to a species' viability, use of such a low
threshold would require us to impose restrictions and expend
conservation resources disproportionately to conservation benefit:
Listing would be rangewide, even if only a portion of the range of
minor conservation importance to the species is imperiled. On the other
hand, it would be inappropriate to establish a threshold for
``significant'' that is too high. This would be the case if the
standard were, for example, that a portion of the range can be
considered ``significant'' only if threats in that portion result in
the entire species' being currently endangered or threatened. Such a
high bar would not give the SPR phrase independent meaning, as the
Ninth Circuit held in Defenders of Wildlife v. Norton, 258 F.3d 1136
(9th Cir. 2001).
The definition of ``significant'' used in this finding carefully
balances these concerns. By setting a relatively high threshold, we
minimize the degree to which restrictions will be imposed or resources
expended that do not contribute substantially to species conservation.
But we have not set the threshold so high that the phrase ``in a
significant portion of its range'' loses independent meaning.
Specifically, we have not set the threshold as high as it was under the
interpretation presented by the Service in the Defenders litigation.
Under that interpretation, the portion of the range would have to be so
important that current imperilment there would mean that the species
would be currently imperiled everywhere. Under the definition of
``significant'' used in this finding, the portion of the range need not
rise to such an exceptionally high level of biological significance.
(We recognize that if the species is imperiled in a portion that rises
to that level of biological significance, then we should conclude that
the species is in fact imperiled throughout all of its range, and that
we would not need to rely on the SPR language for such a listing.)
Rather, under this interpretation, we ask whether the species would be
endangered everywhere without that portion (i.e., if that portion were
completely extirpated). In other words, the portion of the range need
not be so important that even the species being in danger of extinction
in that portion would be sufficient to cause the species in the
remainder of the range to be endangered; rather, the complete
extirpation (in a hypothetical future) of the species in that portion
would be required to cause the species in the remainder of the range to
be endangered.
The range of a species can theoretically be divided into portions
in an infinite number of ways. However, there is no purpose to
analyzing portions of the range that have no reasonable potential to be
significant or to analyzing portions of the range in which there is no
reasonable potential for the species to be endangered or threatened. To
identify only those portions that warrant further consideration, we
determine whether there is substantial information indicating that: (1)
The portions may be ``significant,'' and (2) the species may be in
danger of extinction there or likely to become so within the
foreseeable future. Depending on the biology of the species, its range,
and the threats it faces, it might be more efficient for us to address
the significance question first or the status question first. Thus, if
we determine that a portion of the range is not ``significant,'' we do
not need to determine whether the species is endangered or threatened
there; if we determine that the species is not endangered or threatened
in a portion of its range, we do not need to determine if that portion
is ``significant.'' In practice, a key part of the determination that a
species is in danger of extinction in a significant portion of its
range is whether the threats are geographically concentrated in some
way. If the threats to the species are essentially uniform throughout
its range, no portion is likely to warrant further consideration.
Moreover, if any concentration of threats to the species occurs only in
portions of the species' range that clearly would not meet the
biologically based definition of ``significant,'' such portions will
not warrant further consideration.
We evaluated the current range of the Baking Powder Flat blue
butterfly to determine if there is any apparent geographic
concentration of the primary stressors potentially affecting the
subspecies including water development, fire, livestock grazing,
nonnative species invasion, agriculture, mining and energy development,
OHV, plant collecting, climate change, and limited range and small
population size. On the basis of our review, we found no geographic
concentration of threats either on public or private lands to suggest
that the Baking Powder Flat blue butterfly may be in danger of
extinction in that portion of its range. We found no area within the
range of the Baking Powder Flat blue butterfly where the potential
threats are significantly concentrated or substantially greater than in
other portions of its range. We also found that lost historical range
does not constitute a significant portion of the range for the Baking
Powder Flat blue butterfly because there is no information indicating
that there has been a range contraction for this subspecies. Therefore,
we find factors affecting the subspecies are essentially uniform
throughout its range, indicating no portion of the butterfly's range
warrants further consideration of possible status as an endangered or
threatened species under the Act.
We found no information to indicate that the Baking Powder Flat
blue butterfly is in danger of extinction now, nor is it likely to
become endangered within the foreseeable future, throughout all or a
significant portion of its range. Therefore, listing the Baking Powder
Flat blue butterfly as an endangered or threatened species under the
Act is not warranted at this time.
We request that you submit any new information concerning the
status of, or threats to, the Baking Powder Flat blue butterfly to our
Nevada Fish and Wildlife Office (see ADDRESSES section) whenever it
becomes available. New information will help us monitor the Baking
Powder Flat blue butterfly and encourage its conservation. If an
emergency situation develops for the Baking Powder Flat blue butterfly
or any other species, we will act to provide immediate protection.

[[Page 54324]]

Species Information for the Bleached Sandhill Skipper

Taxonomy and Species Description

We accept the characterization of the bleached sandhill skipper
(Polites sabuleti sinemaculata) as a valid subspecies based on its
description by Austin (1987, pp. 7-8). This subspecies is in the
Hesperiidae family (Austin 1998a, p. 838). The male's wingspan ranges
from 0.47 to 0.53 in (11.9-13.4 mm). The upperside is bright golden-
orange with a black stigma on the primaries. The dark margin of the
primaries is absent to faint. The terminal line is black. Wing fringes
are the same as the wing color. The secondaries do not have an outer
marginal border. The black along the costal (leading edge) margin is
narrow, and the base of the wing is lightly dusted with black. The
terminal line and wing fringes are like they are on the primaries. The
underside of the wing is paler than the upperside. The black of the
primaries is restricted to the base of the cell and along the posterior
margin. The secondaries have a faint cobweb pattern (Austin 1987, pp.
7-8). The female's wingspan ranges from 0.52 to 0.59 in (13.1-15.0 mm).
The upperside of the wing is a pale yellow-orange. The postmedial (on
the wing, just past the middle) area of the primaries is whitish-
yellow. The terminal line is dark gray, and fringes are grayish on the
primaries and white on the secondaries. The underside is paler than on
the male. The postmedial areas of the primaries and the postmedian band
and secondaries are ghostly white (Austin 1987, p. 8). Please refer to
Austin (1987, p. 8) for a more detailed description of this subspecies.

Distribution and Habitat

The bleached sandhill skipper is known from one location (Baltazor
Hot Spring) located west of Denio Junction, Humboldt County, located in
northwestern Nevada (Austin 1987, p. 8; Austin et al., in litt. 2000,
p. 4; NNHP 2010; B. Boyd, pers. comm. cited in WildEarth Guardians
2010, p. 15) (on BLM and private lands). Austin (1987, p. 8) indicates
that other areas of the Baltazor Hot Spring drainage system need to be
investigated for possible other populations. The area is a salt flat
near a hot spring and is densely covered with Distichlis spicata (salt
grass) (Austin 1987, p. 8), this subspecies' possible host plant (see
Biology section). The size of the known occupied site or the extent of
this subspecies' host plant(s), or host plant abundance, has not been
reported.

Biology

Distichlis spicata may serve as the larval host plant (Austin 1987,
p. 8); this species is a perennial grass (http://www.plants.usda.gov,
accessed April 24, 2012) and is common and widespread in Nevada
(Kartesz, 1987, p. 1611). This plant can be found in wetland and non-
wetland areas in Nevada (Reed 1988, p. 24). It is common and can be
found throughout most of the United States (http://www.plants.usda.gov,
accessed April 24, 2012). In the western United States, it can be found
in Washington, Oregon, California, Idaho, Montana, Nevada, Utah,
Arizona, and New Mexico (Kartesz, 1987, p. 1611; http://www.plants.usda.gov, accessed April 24, 2012).
Adults have been seen nectaring on white and yellow composites
(Asteraceae) (Sunflower family) (Austin 1987, p. 8), but specific
nectar plant species are not identified. It is possible that adults
nectar on a variety of plants that are in flower during their flight
period. Adults are known to fly during late August to mid September,
and it is unknown if earlier broods occur (Austin 1987, p. 8; Austin et
al., in litt. 2000, p. 4).
There is little biological information available at the subspecies
level, but some inferences can be made from biological information from
related species at the species level. Information for the saltgrass
skipper (Polites sabuleti) indicates eggs are pale bluish-green,
turning cream-colored; eggs are laid singly on the host plant or other
nearby plants or soil (Scott 1986, p. 443). Larvae eat leaves, and they
live in tied-leaf nests (Scott 1986, p. 443). Males perch in low grassy
areas during the day seeking females (Scott 1986, p. 444).
According to the petition, thousands of bleached sandhill skippers
have been seen in the past (A. Warren, pers. comm. cited in WildEarth
Guardians 2010, p. 15), but the population appears to have declined 2-3
years ago (B. Boyd, pers. comm. cited in WildEarth Guardians 2010, p.
15). The cause or potential cause of this apparent decline is not
reported in the petition. The available information does not indicate
whether a population decline, if accurate, is unusual or not as
butterfly populations are highly dynamic from year to year (Weiss et
al. 1997, p. 2). The best available information does not include
surveys documenting population size, number of extirpated populations
or sites, if any, or population trends (other than that mentioned
above).

Five-Factor Evaluation for the Bleached Sandhill Skipper

Information pertaining to the bleached sandhill skipper in relation
to the five factors provided in section 4(a)(1) of the Act is discussed
below.

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

Potential factors that may affect the habitat or range of the
bleached sandhill skipper are discussed in this section, including: (1)
Water development, (2) livestock grazing, (3) energy development, and
(4) climate change.
Water Development
For general background information on water development, please
refer to the Water Development section under Factor A. The Present or
Threatened Destruction, Modification, or Curtailment of Its Habitat or
Range in the Five-Factor Evaluation for the White River Valley Skipper.
Austin et al. (in litt. 2000, p. 4) state that the bleached
sandhill skipper could be impacted by water table changes, but specific
information is not provided to support this claim. The Baltazor Meadow-
Continental Lake wetland area is estimated to have had 20 percent of
its wetland area degraded or converted to other land uses, such as by
water development (NNHP 2007, p. 36). The Baltazor Meadow-Continental
Lake wetland area includes the Baltazor Hot Spring where the bleached
sandhill skipper is known to occur and an additional area, Continental
Lake, located to the south where the bleached sandhill skipper is not
known to occur. The NNHP (2007) does not delineate these wetland areas
on a map or define them in terms of acreage; therefore, the amount of
bleached sandhill skipper habitat that may occur within these areas and
may be impacted by various activities is not indicated. The extent to
which the various land use practices have degraded or converted these
areas is also not individually delineated or quantified by NNHP (2007).
Therefore, we cannot determine the amount of overlap between the
estimated wetland impacts identified by the NNHP and the distribution
of the bleached sandhill skipper. Bleached sandhill skipper habitat
will not be impacted by the SNWA water development project because the
project is proposed in southern and eastern Nevada and in groundwater
basins not connected to the basin where this skipper occurs.
While it is likely that human water demands have impacted this
drainage system over the decades, pumping of

[[Page 54325]]

the Baltazor Hot Spring does not currently occur (Lawson 2012, per.
comm.). The best available information does not indicate that changes
due to water development have occurred in the area occupied by the
bleached sandhill skipper and are negatively impacting the habitat of
this subspecies. Actions regarding water management in bleached
sandhill skipper habitat in the future would be addressed in
consideration of Nevada water law. We did not receive any additional
information as a result of our 90-day petition finding notice, nor did
we locate information that indicates water development is impacting the
subspecies' habitat. Therefore, the best available information does not
indicate that water development is modifying the subspecies' habitat to
an extent that it represents a threat to the bleached sandhill skipper
population now or in the future.
Livestock Grazing
For general background information on livestock grazing, please
refer to the Livestock Grazing section under Factor A. The Present or
Threatened Destruction, Modification, or Curtailment of Its Habitat or
Range in the Five-Factor Evaluation for the White River Valley Skipper.
A portion of the Baltazor Meadow-Continental Lake wetland area has
been identified as degraded or converted to other land uses, including
livestock grazing (NNHP 2007, p. 36). The Baltazor Hot Spring and most
of the vegetation associated with bleached sandhill skipper habitat
(approximately 100 ac (40.5 ha)) is located within the Continental
Pasture of the Pueblo Mountain Allotment on BLM-administered lands
(Lawson 2012, pers. comm.). The pasture is on a 3-year rotation with
cattle grazing occurring 2 out of every 3 years for 1 month in August;
the permittee usually does not graze the entire month (Lawson 2012,
pers. comm.). The area is not heavily grazed, and the habitat looks to
be in good condition (Lawson 2012, pers. comm.). The possible larval
host plant, Distichlis spicata, is common here and widespread in
Nevada. The Asteraceae Family is a large plant family comprising
numerous species, several of which the adults may be using as nectar
sources. The best available information does not indicate a decline in
either the possible larval host plant or probable adult nectar source
populations within the bleached sandhill skipper's habitat due to
livestock grazing.
Actions involving livestock grazing within bleached sandhill
skipper habitat are addressed in consideration of the Winnemucca
District Record of Decision and Approved RMP (BLM 2010a) (see Factor D
discussion under White River Valley skipper), BLM's authority under
Regulations on Grazing Administration Exclusive of Alaska, BLM's 6840
Manual (BLM 2008b), and possibly NEPA (see our discussion of these
authorities above, under White River Valley skipper). We did not
receive any information as a result of our 90-day petition finding
notice, nor did we locate information indicating that livestock grazing
is negatively impacting the habitat or the known population of the
bleached sandhill skipper. Thus, the best available information does
not indicate that livestock grazing is modifying the subspecies'
habitat to the extent that it represents a threat to this subspecies
now or in the future.
Energy Development
For general background information on energy development, please
refer to the Energy Development section under Factor A. The Present or
Threatened Destruction, Modification, or Curtailment of Its Habitat or
Range in the Five-Factor Evaluation for the White River Valley Skipper.
A portion of the Baltazor Meadow-Continental Lake wetland area has
been identified as degraded or converted to other land uses, including
energy development (NNHP 2007, p. 36). Energy development is not
occurring within the bleached sandhill skipper habitat (Lawson 2012,
pers. comm.). Any actions involving energy development within bleached
sandhill skipper habitat would be addressed in consideration of the
Winnemucca District Record of Decision and Approved RMP (BLM 2010a),
the FLPMA of 1976, BLM's 6840 Manual (BLM 2008b), and NEPA (see our
discussion of these authorities above under White River Valley
skipper). We did not receive any information as a result of our 90-day
petition finding notice, nor did we locate information indicating that
energy development is negatively impacting the bleached sandhill
skipper population or its habitat. Thus, the best available information
does not indicate that energy development is modifying the subspecies'
habitat to the extent that it represents a threat to this subspecies
now or in the future.
Climate Change
For general background information on climate change, please refer
to the Climate Change section under Factor A. The Present or Threatened
Destruction, Modification, or Curtailment of Its Habitat or Range in
the Five-Factor Evaluation for the White River Valley Skipper.
It is difficult to predict local climate change impacts, due to
substantial uncertainty in trends of hydrological variables,
limitations in spatial and temporal coverage of monitoring networks,
and differences in the spatial scales of global climate models and
hydrological models (Bates et al. 2008, p. 3). We found no information
on how climate change may impact the bleached sandhill skipper's
potential host plant, Distichlis spicata, or adult nectar sources. In
general, increasing temperatures and drought frequency, more winter
precipitation in the form of rain, possible decreases in summer rain,
and earlier, rapid snowmelt could impact the host plant by causing
physiological stress, altering phenology, reducing recruitment events,
and reducing seed establishment. However, at this time, it is difficult
to predict local climate change impacts to Distichlis spicata and how
individual plant species will react to climate change, especially for a
species which is common and grows in both wet and dry areas. Thus,
while information indicates that climate change has the potential to
affect vegetation and habitats used by the bleached sandhill skipper in
the Great Basin, there is much uncertainty regarding which habitat
attributes could be affected, and the timing, magnitude, and rate of
their change as it relates to this subspecies.
The best available information does not indicate that climate
change is impacting occupied bleached sandhill skipper habitat. We did
not receive any information as a result of our 90-day petition finding
notice, nor did we locate specific information that indicates climate
change is negatively impacting bleached sandhill skipper habitat.
Therefore, the best available information does not indicate that
climate change is modifying the subspecies' habitat to the extent that
it represents a threat to this subspecies now or in the future.
Summary of Factor A
While a few activities such as water development and livestock
grazing may be impacting a portion of the Baltazor Meadow-Continental
Lake wetland area, the available information does not indicate that
these activities or climate change are negatively impacting the
bleached sandhill skipper population or its habitat. Therefore, we
conclude based on the best scientific and commercial information
available that the present or threatened destruction, modification, or
curtailment of its habitat or range does not currently pose

[[Page 54326]]

a threat to the bleached sandhill skipper, now or is it likely to
become a threat to the subspecies in the future.

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

For general background information on overutilization, please refer
to the discussion on collecting under Factor B. Overutilization for
Commercial, Recreational, Scientific, or Educational Purposes in the
Five-Factor Evaluation for the White River Valley Skipper.
We are unaware of any studies analyzing impacts of removal of
individuals from populations of the bleached sandhill skipper.
According to Austin (1987, p. 8), 27 males and 14 females were
collected between 1984 and 1985 at one site. No additional information
is known about the numbers of specimens collected in the past, and we
are not aware of any ongoing or current collecting of this subspecies.
Given the low number of individuals collected over this 2-year period,
the length of time since the collections were made, and the lack of
information about the relative impact to the populations, the available
information does not indicate that collection may be a threat to this
subspecies.
We found no information indicating that overutilization has led to
the loss of populations or a significant reduction in numbers of
individuals for this subspecies. Therefore, we conclude based on the
best scientific and commercial information available that
overutilization for commercial, recreational, scientific, or
educational purposes does not currently pose a threat to the bleached
sandhill skipper, nor is it likely to become a threat to the subspecies
in the future.

Factor C. Disease or Predation

We found no information on the incidence of disease in the bleached
sandhill skipper.
We assume that predation by other species, such as birds or
insects, on eggs, larvae, pupae, or adult bleached sandhill skippers
occurs, but we found no information indicating that predation levels
are any greater than naturally occurring levels typical of the
biological community in which the bleached sandhill skipper occurs.
Available information does not indicate that there are impacts from
disease or predation on the bleached sandhill skipper. Therefore, we
conclude based on the best scientific and commercial information
available that disease or predation does not currently pose a threat to
the bleached sandhill skipper, nor is either likely to become a threat
to the subspecies in the future.

Factor D. The Inadequacy of Existing Regulatory Mechanisms

The discussion of existing regulatory mechanisms under Factor D for
the White River Valley skipper is hereby incorporated into this
discussion for the bleached sandhill skipper. As discussed above under
Factor D for the White River Valley skipper, Nevada State law
pertaining to wildlife does not offer protection to the bleached
sandhill skipper specifically because it is an invertebrate species not
classified as wildlife. Although not protected by State wildlife law,
the best available information, as discussed in Factor B, does not
indicate that collection or other forms of overutilization is a threat
to the bleached sandhill skipper.
A large portion of habitat for the bleached sandhill skipper occurs
on Federal lands administered by BLM. Numerous policies, guidance, and
laws have been developed to assist the agency in management of these
lands (see Factor D discussion under White River Valley skipper). BLM
policies and guidance address species of concern, actions covered by
RMPs, and regulatory authority for grazing and oil and gas leasing and
operating activities. As discussed under Factor A, the best available
information does not indicate that activities such as livestock grazing
and mining and energy development that are regulated by various
policies, guidance, and laws on Federal lands are impacting the habitat
of the bleached sandhill skipper. We conclude based on the best
available commercial and scientific information that the inadequacy of
existing regulatory mechanisms does not pose a threat to the bleached
sandhill skipper, nor is it likely to become a threat to the subspecies
in the future.

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

Potential other natural or manmade factors that may affect the
continued existence of the bleached sandhill skipper are discussed in
this section and include: (1) Limited range and (2) small population
size(s).
For general background information on other natural or manmade
factors which could affect the bleached sandhill skipper, please refer
to the discussion on limited distribution and population size under
Factor E. Other Natural or Manmade Factors Affecting Its Continued
Existence in the Five-Factor Evaluation for the White River Valley
Skipper.
The bleached sandhill skipper is currently known from only one area
(Baltazor Hot Spring) near Denio Junction, Humboldt County, Nevada (see
Distribution and Habitat section). However, Austin (1987, p. 8)
indicates that other areas of the Baltazor Hot Springs drainage system
need to be investigated for possible other populations. The petition
reports that although thousands had been seen in the past, a decline
appears to have occurred 2-3 years ago (A. Warren, pers. comm. and B.
Boyd, pers. comm., cited in WildEarth Guardians 2010, p. 15), but
details regarding this decline or a reason(s) for it are not provided
in the petition. It is unknown whether or not this decline, if
accurate, can be attributed to the normal natural fluctuations of
butterfly populations. Butterfly populations are highly dynamic, and
numbers and distribution can be highly variable year to year (Weiss et
al. 1997, p. 2).
Little information is available related to population numbers,
size, or trends for the bleached sandhill skipper. Information
pertaining to the aerial extent of habitat or populations is not
available. The available information does not include comprehensive
surveys for this subspecies though researchers have recommended these
surveys to determine if additional populations exist. Without data to
indicate population trends, it is difficult to support claims of
adverse impacts to the bleached sandhill skipper. We found no
information on connections between chance events and population impacts
for the bleached sandhill skipper. In the absence of chance events
connected to known populations, we do not consider restricted
geographic range or small population numbers by themselves to be
threats to a species. The best available information does not indicate
that the bleached sandhill skipper is negatively impacted by limited
range or small population numbers. Therefore, we conclude based on the
best available scientific and commercial information that other natural
or manmade factors do not currently pose a threat to the bleached
sandhill skipper, nor are they likely to become a threat to the
subspecies in the future.

Synergistic Interactions Between Threat Factors

We have evaluated individual threats to the bleached sandhill
skipper. This subspecies faces potential threats from water
development, livestock grazing, energy development, climate change,
limited range, and small population

[[Page 54327]]

size. In considering whether the threats to a species may be so great
as to warrant listing under the Act, we must look beyond the possible
impacts of potential threats in isolation and consider the potential
cumulative impacts of all of the threats facing a species.
In making this finding, we considered whether there may be
cumulative effects to the bleached sandhill skipper from the combined
impacts of the existing stressors such that even if each stressor
individually does not result in population-level impacts, that
cumulatively the effects may be significant. We considered whether the
combined effects of water development and energy development may result
in a significant impact to the bleached sandhill skipper because these
potential impacts have the potential to result in some level of habitat
loss. However, we conclude that synergistic effects between water
development and energy development will not result in a significant
overall population impact to the bleached sandhill skipper because
these activities have not been found to occur within this subspecies'
habitat. While livestock grazing could impact habitat of the bleached
sandhill skipper, BLM policies and management provide terms and
conditions for livestock grazing to protect resources, and we conclude
that livestock grazing is not of sufficient severity, frequency, or
geographic scope to result in significant habitat impacts or cause
population-level impacts to the bleached sandhill skipper.
Limited range and small population size could make the bleached
sandhill skipper more vulnerable to potential threats discussed above.
However, we cannot conclude that synergistic effects between limited
range and small population size and other potential threats are
operative threats to the continued existence of the bleached sandhill
skipper given the lack of information on the range and population size
of this butterfly. There is no information on population size or change
in population abundance for the bleached sandhill skipper, and the
limited information on occurrence (distribution) is insufficient to
define this skipper's range.
Synergistic interactions are possible between effects of climate
change and effects of other stressors such as livestock grazing.
Increases in carbon dioxide and temperature and changes in
precipitation are likely to affect vegetation, and the bleached
sandhill skipper is closely associated with the presence of vegetation.
However, it is difficult to project how climate change will affect
vegetation because certain plant species may increase in cover while
other species may decrease. Uncertainty about how different plant
species will respond under climate change, combined with uncertainty
about how changes in plant species composition would affect suitability
of bleached sandhill skipper habitat, make projecting possible
synergistic effects of climate change on the bleached sandhill skipper
too speculative.

Finding for the Bleached Sandhill Skipper

As required by the Act, we considered the five factors in assessing
whether the bleached sandhill skipper is an endangered or threatened
species throughout all of its range. We examined the best scientific
and commercial information available regarding the past, present, and
future threats faced by this subspecies.
Factors potentially affecting the bleached sandhill skipper
including water development, livestock grazing, energy development, or
climate change, and limited range and small population size, are either
limited in scope or lack documentation that they are occurring in
occupied habitat and adversely impacting the subspecies. Though climate
change may be affecting the bleached sandhill skipper and its habitats,
and effects are likely to increase in the future, the available
information does not support a determination that climate change will
have a population-level impact on this subspecies. The available
information also does not indicate that overutilization, disease, or
predation is negatively impacting the bleached sandhill skipper. There
is also no indication that existing regulatory mechanisms are
inadequate to protect the subspecies from potential threats.
Furthermore, there is no evidence to suggest that the combined
stressors acting together are a threat to the bleached sandhill
skipper. Based on our review of the best scientific and commercial
information available, we find these stressors, either singly or in
combination with one another, are not threats to the bleached sandhill
skipper.
We found no information to indicate that threats are of sufficient
imminence, intensity, or magnitude such that the bleached sandhill
skipper is in danger of extinction (endangered) or likely to become
endangered within the foreseeable future (threatened), throughout all
of its range. Therefore, we find that listing the bleached sandhill
skipper as an endangered or threatened species is not warranted
throughout its range.

Significant Portion of the Range

Having determined that the bleached sandhill skipper does not meet
the definition of an endangered or a threatened species, we must next
consider whether there are any significant portions of the range where
the bleached sandhill skipper is in danger of extinction or is likely
to become endangered in the foreseeable future. The Act defines
``endangered species'' as any species which is ``in danger of
extinction throughout all or a significant portion of its range,'' and
``threatened species'' as any species which is ``likely to become an
endangered species within the foreseeable future throughout all or a
significant portion of its range.'' 16 U.S.C. 1532(6) and 1532(20). The
definition of ``species'' is also relevant to this discussion. The Act
defines ``species'' as follows: ``The term `species' includes any
subspecies of fish or wildlife or plants, and any distinct population
segment of any species of vertebrate fish or wildlife which interbreeds
when mature.'' 16 U.S.C. 1532(16). The phrase ``significant portion of
its range'' (SPR) is not defined by the statute, and we have never
addressed in our regulations: (1) The consequences of a determination
that a species is either endangered or likely to become so throughout a
significant portion of its range, but not throughout all of its range;
or (2) what qualifies a portion of a range as ``significant.''
Two recent district court decisions have addressed whether the SPR
language allows the Service to list or protect less than all members of
a defined ``species'': Defenders of Wildlife v. Salazar, 729 F. Supp.
2d 1207 (D. Mont. 2010), concerning the Service's delisting of the
Northern Rocky Mountains gray wolf (74 FR 15123, April 2, 2009); and
WildEarth Guardians v. Salazar, 2010 U.S. Dist. LEXIS 105253 (D. Ariz.
September 30, 2010), concerning the Service's 2008 finding on a
petition to list the Gunnison's prairie dog (73 FR 6660, February 5,
2008). The Service had asserted in both of these determinations that,
under the Act, it had authority, in effect, to protect only some
members of a ``species,'' as defined by the Act (i.e., species,
subspecies, or DPS). Both courts ruled that the determinations were
arbitrary and capricious on the grounds that this approach violated the
plain and unambiguous language of the Act. The courts concluded that
reading the SPR language to allow protecting only a portion of a
species' range is inconsistent with the Act's definition of

[[Page 54328]]

``species.'' The courts concluded that once a determination is made
that a species (i.e., species, subspecies, or DPS) meets the definition
of ``endangered species'' or ``threatened species,'' it must be placed
on the list in its entirety and the Act's protections applied
consistently to all members of that species throughout its range
(subject to modification of protections through special rules under
sections 4(d) and 10(j) of the Act).
Consistent with that interpretation, and for the purposes of this
finding, we interpret the phrase ``significant portion of its range''
in the Act's definitions of ``endangered species'' and ``threatened
species'' to provide an independent basis for listing. Thus there are
two situations (or factual bases) under which a species would qualify
for listing: A species may be endangered or threatened throughout all
of its range, or a species may be endangered or threatened in only a
significant portion of its range. If a species is in danger of
extinction throughout an SPR, it, the species, is an ``endangered
species.'' The same analysis applies to ``threatened species.'' Based
on this interpretation and supported by existing case law, the
consequence of finding that a species is endangered or threatened in
only a significant portion of its range is that the entire species
shall be listed as endangered or threatened, respectively, and the
Act's protections shall be applied across the species' entire range.
We conclude, for the purposes of this finding, that interpreting
the SPR phrase as providing an independent basis for listing is the
best interpretation of the Act because it is consistent with the
purposes and the plain meaning of the key definitions of the Act; it
does not conflict with established past agency practice (i.e., prior to
the 2007 Solicitor's Opinion), as no consistent, long-term agency
practice has been established; and it is consistent with the judicial
opinions that have most closely examined this issue. Having concluded
that the phrase ``significant portion of its range'' provides an
independent basis for listing and protecting the entire species, we
next turn to the meaning of ``significant'' to determine the threshold
for when such an independent basis for listing exists.
Although there are potentially many ways to determine whether a
portion of a species' range is ``significant,'' we conclude, for the
purposes of this finding, that the significance of the portion of the
range should be determined based on its biological contribution to the
conservation of the species. For this reason, we describe the threshold
for ``significant'' in terms of an increase in the risk of extinction
for the species. We conclude that a biologically based definition of
``significant'' best conforms to the purposes of the Act, is consistent
with judicial interpretations, and best ensures species' conservation.
Thus, for the purposes of this finding, and as explained further below,
a portion of the range of a species is ``significant'' if its
contribution to the viability of the species is so important that,
without that portion, the species would be in danger of extinction.
We evaluate biological significance based on the principles of
conservation biology using the concepts of redundancy, resiliency, and
representation. Resiliency describes the characteristics of a species
and its habitat that allow it to recover from periodic disturbance.
Redundancy (having multiple populations distributed across the
landscape) may be needed to provide a margin of safety for the species
to withstand catastrophic events. Representation (the range of
variation found in a species) ensures that the species' adaptive
capabilities are conserved. Redundancy, resiliency, and representation
are not independent of each other, and some characteristic of a species
or area may contribute to all three. For example, distribution across a
wide variety of habitat types is an indicator of representation, but it
may also indicate a broad geographic distribution contributing to
redundancy (decreasing the chance that any one event affects the entire
species), and the likelihood that some habitat types are less
susceptible to certain threats, contributing to resiliency (the ability
of the species to recover from disturbance). None of these concepts is
intended to be mutually exclusive, and a portion of a species' range
may be determined to be ``significant'' due to its contributions under
any one or more of these concepts.
For the purposes of this finding, we determine if a portion's
biological contribution is so important that the portion qualifies as
``significant'' by asking whether, without that portion, the
representation, redundancy, or resiliency of the species would be so
impaired that the species would have an increased vulnerability to
threats to the point that the overall species would be in danger of
extinction (i.e., would be ``endangered''). Conversely, we would not
consider the portion of the range at issue to be ``significant'' if
there is sufficient resiliency, redundancy, and representation
elsewhere in the species' range that the species would not be in danger
of extinction throughout its range if the population in that portion of
the range in question became extirpated (extinct locally).
We recognize that this definition of ``significant'' (a portion of
the range of a species is ``significant'' if its contribution to the
viability of the species is so important that, without that portion,
the species would be in danger of extinction) establishes a threshold
that is relatively high. On the one hand, given that the consequences
of finding a species to be endangered or threatened in an SPR would be
listing the species throughout its entire range, it is important to use
a threshold for ``significant'' that is robust. It would not be
meaningful or appropriate to establish a very low threshold whereby a
portion of the range can be considered ``significant'' even if only a
negligible increase in extinction risk would result from its loss.
Because nearly any portion of a species' range can be said to
contribute some increment to a species' viability, use of such a low
threshold would require us to impose restrictions and expend
conservation resources disproportionately to conservation benefit:
Listing would be rangewide, even if only a portion of the range of
minor conservation importance to the species is imperiled. On the other
hand, it would be inappropriate to establish a threshold for
``significant'' that is too high. This would be the case if the
standard were, for example, that a portion of the range can be
considered ``significant'' only if threats in that portion result in
the entire species' being currently endangered or threatened. Such a
high bar would not give the SPR phrase independent meaning, as the
Ninth Circuit held in Defenders of Wildlife v. Norton, 258 F.3d 1136
(9th Cir. 2001).
The definition of ``significant'' used in this finding carefully
balances these concerns. By setting a relatively high threshold, we
minimize the degree to which restrictions will be imposed or resources
expended that do not contribute substantially to species conservation.
But we have not set the threshold so high that the phrase ``in a
significant portion of its range'' loses independent meaning.
Specifically, we have not set the threshold as high as it was under the
interpretation presented by the Service in the Defenders litigation.
Under that interpretation, the portion of the range would have to be so
important that current imperilment there would mean that the species
would be currently imperiled everywhere. Under the definition of
``significant'' used in this finding, the portion of the range need not
rise to such an exceptionally high level of

[[Page 54329]]

biological significance. (We recognize that if the species is imperiled
in a portion that rises to that level of biological significance, then
we should conclude that the species is in fact imperiled throughout all
of its range, and that we would not need to rely on the SPR language
for such a listing.) Rather, under this interpretation, we ask whether
the species would be endangered everywhere without that portion (i.e.,
if that portion were completely extirpated). In other words, the
portion of the range need not be so important that even the species
being in danger of extinction in that portion would be sufficient to
cause the species in the remainder of the range to be endangered;
rather, the complete extirpation (in a hypothetical future) of the
species in that portion would be required to cause the species in the
remainder of the range to be endangered.
The range of a species can theoretically be divided into portions
in an infinite number of ways. However, there is no purpose to
analyzing portions of the range that have no reasonable potential to be
significant or to analyzing portions of the range in which there is no
reasonable potential for the species to be endangered or threatened. To
identify only those portions that warrant further consideration, we
determine whether there is substantial information indicating that: (1)
The portions may be ``significant,'' and (2) the species may be in
danger of extinction there or likely to become so within the
foreseeable future. Depending on the biology of the species, its range,
and the threats it faces, it might be more efficient for us to address
the significance question first or the status question first. Thus, if
we determine that a portion of the range is not ``significant,'' we do
not need to determine whether the species is endangered or threatened
there; if we determine that the species is not endangered or threatened
in a portion of its range, we do not need to determine if that portion
is ``significant.'' In practice, a key part of the determination that a
species is in danger of extinction in a significant portion of its
range is whether the threats are geographically concentrated in some
way. If the threats to the species are essentially uniform throughout
its range, no portion is likely to warrant further consideration.
Moreover, if any concentration of threats to the species occurs only in
portions of the species' range that clearly would not meet the
biologically based definition of ``significant,'' such portions will
not warrant further consideration.
We evaluated the current range of the bleached sandhill skipper to
determine if there is any apparent geographic concentration of the
primary stressors potentially affecting the subspecies including water
development, livestock grazing, energy development, climate change, and
limited range and small population size. On the basis of our review, we
found no geographic concentration of threats either on public or
private lands to suggest that the bleached sandhill skipper may be in
danger of extinction in that portion of its range. We found no area
within the range of the bleached sandhill skipper where the potential
threats are significantly concentrated or substantially greater than in
other portions of its range. We also found that lost historical range
does not constitute a significant portion of the range for the bleached
sandhill skipper because there is no information indicating that there
has been a range contraction for this subspecies. Therefore, we find
factors affecting the subspecies are essentially uniform throughout its
range, indicating no portion of the skipper's range warrants further
consideration of possible status as an endangered or threatened species
under the Act.
We found no information to indicate that the bleached sandhill
skipper is in danger of extinction now, nor is it likely to become
endangered within the foreseeable future, throughout all or a
significant portion of its range. Therefore, listing the bleached
sandhill skipper as an endangered or threatened species under the Act
is not warranted at this time.
We request that you submit any new information concerning the
status of, or threats to, the bleached sandhill skipper to our Nevada
Fish and Wildlife Office (see ADDRESSES section) whenever it becomes
available. New information will help us monitor the bleached sandhill
skipper and encourage its conservation. If an emergency situation
develops for the bleached sandhill skipper or any other species, we
will act to provide immediate protection.

References Cited

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

Authors

The primary authors of this notice are the staff members of the
Nevada Fish and Wildlife Office (see FOR FURTHER INFORMATION CONTACT).

Authority

The authority for this action is the Endangered Species Act of
1973, as amended (16 U.S.C. 1531 et seq.).

Dated: August 20, 2012.
Benjamin N. Tuggle,
Acting Director, U.S. Fish and Wildlife Service.
[FR Doc. 2012-21243 Filed 8-31-12; 8:45 am]
BILLING CODE 4310-55-P