[Federal Register Volume 76, Number 192 (Tuesday, October 4, 2011)]
[Proposed Rules]
[Pages 61532-61554]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2011-25324]



[[Page 61531]]

Vol. 76

Tuesday,

No. 192

October 4, 2011

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; 90-Day Finding on a 
Petition To List 10 Subspecies of Great Basin Butterflies as Threatened 
or Endangered With Critical Habitat; Proposed Rule

  Federal Register / Vol. 76 , No. 192 / Tuesday, October 4, 2011 / 
Proposed Rules  

[[Page 61532]]


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DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17

[FWS-R8-ES-2010-0097; 92210-1111-0000-B2]


Endangered and Threatened Wildlife and Plants; 90-Day Finding on 
a Petition To List 10 Subspecies of Great Basin Butterflies as 
Threatened or Endangered With Critical Habitat

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Notice of petition finding and initiation of status review.

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SUMMARY: We, the U.S. Fish and Wildlife Service (Service), announce a 
90-day finding on a petition to list 10 subspecies of Great Basin 
butterflies in Nevada and California as threatened or endangered under 
the Endangered Species Act of 1973, as amended (Act), and designate 
critical habitat. Based on our review, we find that the petition 
presents substantial scientific or commercial information indicating 
that listing the following 4 of the 10 subspecies as threatened or 
endangered may be warranted: Baking Powder Flat blue butterfly, 
bleached sandhill skipper, Steptoe Valley crescentspot, and White River 
Valley skipper. Therefore, with the publication of this notice, we are 
initiating a review of the status of these four subspecies to determine 
if listing these subspecies is warranted. To ensure that this status 
review is comprehensive, we are requesting scientific and commercial 
data and other information regarding these four subspecies. Based on 
the status review, we will issue a 12-month finding on these four 
subspecies, which will address whether the petitioned action is 
warranted under the Act.
    We find that the petition does not present substantial scientific 
or commercial information indicating that listing the remaining 6 of 
the 10 subspecies as threatened or endangered may be warranted: Carson 
Valley silverspot, Carson Valley wood nymph, Mattoni's blue butterfly, 
Mono Basin skipper, and the two Railroad Valley skipper subspecies. 
However, we ask the public to submit to us any new information that 
becomes available concerning the status of, or threats to, these four 
subspecies or their habitat at any time.

DATES: To allow us adequate time to conduct this review, we request 
that we receive information on or before December 5, 2011. Please note 
that if you are using the Federal eRulemaking Portal (see ADDRESSES 
section, below), the deadline for submitting an electronic comment is 
11:59 p.m. Eastern Standard Time on this date. After December 5, 2011, 
you must submit information directly to the Field Office (see FOR 
FURTHER INFORMATION CONTACT section below). Please note that we might 
not be able to address or incorporate information that we receive after 
the above requested date.

ADDRESSES: You may submit information by one of the following methods:
     Federal eRulemaking Portal: http://www.regulations.gov. 
Follow the instructions for submitting comments to Docket No. FWS-R8-
ES-2010-0097. Check the box that reads ``Open for Comment/Submission,'' 
and then click the Search button. You should then see an icon that 
reads ``Submit a Comment.'' Please ensure that you have found the 
correct rulemaking before submitting your comment.
     U.S. mail or hand-delivery: Public Comments Processing, 
Attn: Docket No. FWS-R8-ES-2010-0097; Division of Policy and Directives 
Management; U.S. Fish and Wildlife Service; 4401 N. Fairfax Drive, MS 
2042-PDM; Arlington, VA 22203.
    We will post all information we receive on http://www.regulations.gov. This generally means that we will post any 
personal information you provide us (see the Request for Information 
section below for more details).

FOR FURTHER INFORMATION CONTACT: Jill A. Ralston, Acting State 
Supervisor, Nevada Fish and Wildlife Office, U.S. Fish and Wildlife 
Service, 1340 Financial Blvd., Suite 234, Reno, NV 89502, 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: We announce a 90-day finding on a petition 
to list 10 subspecies of Great Basin butterflies in Nevada and 
California as threatened or endangered under the Act and designate 
critical habitat. The petitioners had requested that we list following 
10 subspecies of Great Basin butterflies in Nevada and California as 
threatened or endangered under the Act and designate critical habitat: 
Baking Powder Flat blue butterfly (Euphilotes bernardino minuta), Mono 
Basin skipper (Hesperia uncas giulianii), bleached sandhill skipper 
(Polites sabuleti sinemaculata), Railroad Valley skipper (Hesperia 
uncas fulvapalla), Carson Valley silverspot (Speyeria nokomis 
carsonensis), Railroad Valley skipper (Hesperia uncas reeseorum), 
Carson Valley wood nymph (Cercyonis pegala carsonensis), Steptoe Valley 
crescentspot (Phyciodes cocyta arenacolor), Mattoni's blue butterfly 
(Euphilotes pallescens mattonii), and White River Valley skipper 
(Hesperia uncas grandiose).
    Based on our review, we find that the petition presents substantial 
scientific or commercial information indicating that listing 4 of the 
10 subspecies as threatened or endangered may be warranted, and we find 
that the petition does not present substantial scientific or commercial 
information indicating that listing the remaining 6 of the 10 
subspecies as threatened or endangered may be warranted.

Request for Information

    When we make a finding that a petition presents substantial 
information indicating that listing a species may be warranted, we are 
required to promptly review the status of the species (status review). 
For the status review to be complete and based on the best available 
scientific and commercial information, we request information on the 
four subspecies of butterflies from governmental agencies, Native 
American Tribes, the scientific community, industry, and any other 
interested parties. We seek information on:
    (1) The species' biology, range, and population trends, including:
    (a) Habitat requirements for feeding, breeding, and sheltering;
    (b) Genetics and taxonomy;
    (c) Historical and current range including distribution patterns;
    (d) Historical and current population levels, and current and 
projected trends; and
    (e) Past and ongoing conservation measures for the species, its 
habitat or both.
    (2) The factors that are the basis for making a listing 
determination for a species under section 4(a) of the Act (16 U.S.C. 
1531 et seq.), which are:
    (a) The present or threatened destruction, modification, or 
curtailment of its habitat or range;
    (b) Overutilization for commercial, recreational, scientific, or 
educational purposes;
    (c) Disease or predation;
    (d) The inadequacy of existing regulatory mechanisms; or
    (e) Other natural or manmade factors affecting its continued 
existence.
    If, after the status review, we determine that listing any of the 
six subspecies is warranted, we will propose critical habitat (see 
definition in section 3(5)(A) of the Act), under

[[Page 61533]]

section 4 of the Act, to the maximum extent prudent and determinable at 
the time we propose to list the species. Therefore, within the 
geographical range currently occupied by the six subspecies, we request 
data and information on:
    (1) What may constitute ``physical or biological features essential 
to the conservation of the species'';
    (2) Where these features are currently found; and
    (3) Whether any of these features may require special management 
considerations or protection.
    In addition, we request data and information on ``specific areas 
outside the geographical area occupied by the species'' that are 
``essential to the conservation of the species.'' Please provide 
specific comments and information as to what, if any, critical habitat 
you think we should propose for designation if any of the six 
subspecies are proposed for listing, and why such habitat meets the 
requirements of section 4 of the Act.
    Please include sufficient information with your submission (such as 
scientific journal articles or other publications) to allow us to 
verify any scientific or commercial information you include.
    Submissions merely stating support for or opposition to the action 
under consideration without providing supporting information, although 
noted, will not be considered in making a determination. Section 
4(b)(1)(A) of the Act directs that determinations as to whether any 
species is an endangered or threatened species must be made ``solely on 
the basis of the best scientific and commercial data available.''
    You may submit your information concerning this status review by 
one of the methods listed in the ADDRESSES section. If you submit 
information via http://www.regulations.gov, your entire submission--
including any personal identifying information--will be posted on the 
Web site. If you submit a hardcopy that includes personal identifying 
information, you may request at the top of your document that we 
withhold this personal identifying information from public review. 
However, we cannot guarantee that we will be able to do so. We will 
post all hardcopy submissions on http://www.regulations.gov.
    Information and supporting documentation that we received and used 
in preparing this finding is available for you to review at http://www.regulations.gov, or you may make an appointment during normal 
business hours at the U.S. Fish and Wildlife Service, Nevada Fish and 
Wildlife Office (see FOR FURTHER INFORMATION CONTACT).

Background

    Section 4(b)(3)(A) of the Act requires that we make a finding on 
whether a petition to list, delist, or reclassify a species presents 
substantial scientific or commercial information indicating that the 
petitioned action may be warranted. We are to base this finding on 
information provided in the petition, supporting information submitted 
with the petition, and information otherwise available in our files. To 
the maximum extent practicable, we are to make this finding within 90 
days of our receipt of the petition and publish our notice of the 
finding promptly in the Federal Register.
    Our standard for substantial scientific or commercial information 
within the Code of Federal Regulations (CFR) with regard to a 90-day 
petition finding is ``that amount of information that would lead a 
reasonable person to believe that the measure proposed in the petition 
may be warranted'' (50 CFR 424.14(b)). If we find that substantial 
scientific or commercial information was presented, we are required to 
promptly review the status of the species, which is subsequently 
summarized in our 12-month finding.

Petition History

    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 threatened or 
endangered and critical habitat be designated under the Act. The 
petition clearly identified itself as such and included the requisite 
identification information for the petitioner, as required by 50 CFR 
424.14(a). In a March 26, 2010, letter to the petitioner, WildEarth 
Guardians, 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. We 
also stated that while we are required to complete a significant number 
of listing and critical habitat actions in Fiscal Year 2010 pursuant to 
court orders, judicially approved settlement agreements, and other 
statutory deadlines, we were able to secure funding in Fiscal Year 2010 
to begin work on the initial finding to determine whether the petition 
provides substantial information indicating that the action may be 
warranted. This finding addresses the petition.

Previous Federal Actions

    On May 22, 1984, we added Mattoni's blue butterfly as Euphilotes 
(=Shijimiaeoides) rita mattonii to our list of candidate species as a 
Category 2 candidate species (49 FR 21664). This subspecies is 
currently known as Euphilotes pallescens mattonii. This subspecies was 
again included in our Category 2 candidate list for November 21, 1991 
(56 FR 58804), at which time we added the remaining nine petitioned 
subspecies as Category 2 candidate species. 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. These nine subspecies included the Carson Valley wood 
nymph (Cercyonis pegala ssp.), now known as Cercyonis pegala 
carsonensis. The Baking Powder Flat blue butterfly was added as 
Euphilotes battoides ssp., now known as Euphilotes bernardino minuta. 
The two Railroad Valley skippers, the White River Valley skipper, and 
the Mono Basin skipper were added as Hesperia uncas ssp. and are now 
known as Hesperia uncas fulvapalla,  Hesperia uncas reeseorum, Hesperia 
uncas grandiosa, and Hesperia uncas giulianii, respectively. The 
Steptoe Valley crescentspot was added as Phyciodes pascoensis ssp. and 
is now known as Phyciodes cocyta arenacolor. The bleached sandhill 
skipper was added under a different common name, Denio sandhill skipper 
(Polites sabuleti sinemaculata). The Carson Valley silverspot was added 
as Speyeria nokomis ssp. and is now known as Speyeria nokomis 
carsonensis. All of these subspecies were maintained as Category 2 
candidates in our November 15, 1994 list (59 FR 58982). Please see 
Table 1.

[[Page 61534]]



    Table 1--Petitioned Great Basin Butterflies, With Their Previous and Current Common and Scientific Names
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                                                                  Previous scientific
         Previous common name            Current common name              name           Current scientific name
----------------------------------------------------------------------------------------------------------------
Mattoni's blue butterfly.............  Mattoni's blue           Euphilotes               Euphilotes pallescens
                                        butterfly.               (=Shijimiaeoides) rita   mattonii.
                                                                 mattonii.
Carson Valley wood nymph.............  Carson Valley wood       Cercyonis pegala ssp...  Cercyonis pegala
                                        nymph.                                            carsonensis.
Baking Powder Flat blue butterfly....  Baking Powder Flat blue  Euphilotes battoides     Euphilotes bernardino
                                        butterfly.               ssp..                    minuta.
Railroad Valley skipper..............  Railroad Valley skipper  Hesperia uncas ssp.....  Hesperia uncas
                                                                                          fulvapalla.
Railroad Valley skipper..............  Railroad Valley skipper  Hesperia uncas ssp.....  Hesperia uncas
                                                                                          reeseorum.
Railroad Valley skipper/White River    White River Valley       Hesperia uncas ssp.....  Hesperia uncas
 Valley skipper.                        skipper.                                          grandiosa.
Railroad Valley skipper/Mono Basin     Mono Basin skipper.....  Hesperia uncas ssp.....  Hesperia uncas
 skipper.                                                                                 giulianii.
Steptoe Valley crescentspot..........  Steptoe Valley           Phyciodes pascoensis     Phyciodes cocyta
                                        crescentspot.            ssp..                    arenacolor.
Denio sandhill skipper...............  Bleached sandhill        Polites sabuleti         Polites sabuleti
                                        skipper.                 sinemaculata.            sinemaculata.
Carson Valley silverspot.............  Carson Valley            Speyeria nokomis ssp...  Speyeria nokomis
                                        silverspot.                                       carsonensis.
----------------------------------------------------------------------------------------------------------------

    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, the Service no longer 
considered Category 2 species as candidates, including the 10 
petitioned butterfly subspecies, and did not include them in the 1996 
list or any subsequent CNORs. The decision to stop considering 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.

Evaluation of Information for This Finding

    Section 4 of the Act (16 U.S.C. 1533) and its implementing 
regulations at 50 CFR 424 set forth the procedures for adding a species 
to, or removing a species from, the Federal Lists of Endangered and 
Threatened Wildlife and Plants. A species may be determined to be an 
endangered or threatened species due to one or more of the five factors 
described in section 4(a)(1) of the Act:
    (a) The present or threatened destruction, modification, or 
curtailment of its habitat or range;
    (b) Overutilization for commercial, recreational, scientific, or 
educational purposes;
    (c) Disease or predation;
    (d) The inadequacy of existing regulatory mechanisms; or
    (e) Other natural or manmade factors affecting its continued 
existence.
    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 threatened or endangered 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 may not be sufficient to 
compel a finding that listing may be warranted. The information shall 
contain evidence sufficient to suggest that these factors may be 
operative threats that act on the species to the point that the species 
may meet the definition of threatened or endangered under the Act.
    In making this 90-day finding, we evaluated whether information 
regarding threats to the 10 butterfly subspecies as presented in the 
petition and other information available in our files, is substantial, 
thereby indicating that the petitioned action may be warranted. Our 
evaluation of this information is presented below.

Summary of Common Information on Species

    The 10 butterfly subspecies included in the petition and evaluated 
in this finding are invertebrates endemic to the Great Basin region of 
Nevada and California. All of the petitioned butterflies are from the 
phylum Arthropoda, class Insecta, order Lepidoptera. Taxonomic families 
for the 10 subspecies are: Hesperiidae (5), Nymphalidae (3), and 
Lycaenidae (2). In specific subspecies sections below, we have included 
a short summary of available population and life-history information 
for each subspecies, as provided in the petition, its references, and 
our files.
    The petition provides information regarding the 10 subspecies' 
rankings according to NatureServe (WildEarth Guardians 2010, pp. 3-4). 
The petitioned butterflies are considered at the subspecies taxonomic 
level and all are ranked as critically impaired or impaired at the 
global, national, or State level (WildEarth Guardians 2010, pp. 3-4). 
While the petition states that the ``definitions of `critically 
impaired' and `impaired' 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 
2010). 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 2010). We found the information related to 
the 10 Great Basin butterflies provided by NatureServe to be limited in 
its usefulness for determining that there is substantial information 
indicating that these species may be warranted for listing under the 
Act.
Summary of Common Threats
    The petition identifies several threats as common to many of the 
petitioned butterfly subspecies using general information applicable to 
most butterfly species: Water development (diversions

[[Page 61535]]

and groundwater pumping), livestock grazing, agriculture, pesticides 
(herbicides and insecticides), inadequate regulatory mechanisms, and 
climate change (WildEarth Guardians 2010, pp. 6-10). In addition, the 
petition claims that all of the subspecies may be biologically 
vulnerable due to limited distribution and small population size or 
numbers of populations (WildEarth Guardians 2010, pp. 6, 10-11). The 
common threats presented in the petition are often associated with 
habitats or general areas that could be suitable for butterfly species, 
but the petition frequently does not associate the threats to actual 
locations known to be occupied by the petitioned subspecies. The 
threats are generally described in the petition, but with little or no 
information on existing or probable impacts to the individual 
petitioned subspecies. We have little to no information available in 
our files to identify potential common threats and connect them to 
existing or probable impacts to the 10 petitioned subspecies. In this 
section, we summarize these common threats to the petitioned subspecies 
as presented in the petition.
    Our conclusion for each subspecies as it relates to each of the 
five factors is based on this summary, in addition to any specific 
threat information provided in the petition or available in our files. 
Our conclusion regarding whether there is substantial scientific or 
commercial information available to indicate that the petitioned action 
is warranted or not is indicated in specific subspecies sections below.
Factor A. The Present or Threatened Destruction, Modification, or 
Curtailment of its Habitat or Range
Water Development
    The petition (WildEarth Guardians 2010, p. 6) suggests that the 
historical range for some of the petitioned butterflies has been 
reduced due to loss and mismanagement of riparian and aquatic habitats, 
including springs and seeps, in northern Nevada (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), and California (Dahl 1990 
cited by Noss et al. 1995, p. 74).
    The petition claims that water development, such as the large 
groundwater pumping project proposed by the Southern Nevada Water 
Authority (SNWA) in Nevada and western Utah, threatens to lower 
aquifers and will likely reduce or eliminate springs and wetlands and 
their associated habitats (Deacon et al. 2007, p. 689). Proposals by 
SNWA would pump 180,800 acre-feet per year (afy) (223,000,000 cubic-
meters per year (m\3\/year)) of groundwater from southern, central, and 
eastern Nevada to the Las Vegas Valley (Deacon et al. 2007, p. 692). 
Other communities are pursuing rights to an additional 870,487 afy 
(1,073,750,000 m\3\/year) of groundwater (Deacon et al. 2007, p. 693). 
In Nevada, this groundwater pumping proposal could lower water tables 
in some valleys from a few feet to several hundred feet (Schaefer and 
Harrill 1995, p. 1; Myers 2006, p. 75). Models have predicted 
groundwater declines of about 1 to 1,600 feet (ft) (0.3 to 488 meters 
(m)) throughout 78 basins from Utah to California (Deacon et al. 2007, 
p. 692). Pumping is expected to reduce flow of regional springs 2 to 14 
percent in the first 100 years, with continued declines over the next 
100 years (Deacon et al. 2007, p. 692). Groundwater withdrawal can 
result in direct and indirect effects to the water table and is likely 
to impact the discharge amount from seeps and springs (Sanford 2006, p. 
400).
    The petition indicates 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 cites a few instances where habitat loss or 
degradation due to water development has occurred at historical 
locations of the petitioned subspecies, or where it is occurring at 
locations currently known to be occupied. However, the petition more 
typically associates water development with habitat types or general 
areas that may be used by the petitioned subspecies.
    Our files include information regarding groundwater development as 
it relates to perennial yield versus committed water resources within 
some hydrographic basins where petitioned butterflies occur or may 
occur. This file information is from the Nevada Division of Water 
Resources' (NDWR) database (http://water.nv.gov/), which we accessed 
and reviewed on January 12, 2010, saving hard copies of groundwater 
information for various basins in Nevada. Where we discuss perennial 
yield and committed water resources and effects of groundwater 
development within this finding, we are referring to information we 
have reviewed from the NDWR database.
    The Nevada State Engineer (NSE) approves and permits groundwater 
rights in Nevada and defines perennial yield as ``the amount of usable 
water from a ground-water aquifer that can be economically withdrawn 
and consumed each year for an indefinite period of time. It cannot 
exceed the natural recharge to that aquifer and ultimately is limited 
to maximum amount of discharge that can be utilized for beneficial 
use.'' The NSE estimates perennial yield for 256 basins and sub-basins 
(areas) in Nevada, and may ``designate'' a groundwater basin, meaning 
the basin ``is being depleted or is in need of additional 
administration, and in the interest of public welfare, [the NSE may] 
declare preferred uses (such as municipal, domestic) in such basins.'' 
Some of the hydrographic areas in which the petitioned butterflies 
occur are ``designated'' by the NSE and permitted groundwater rights 
approach or exceed the estimated average annual recharge. Such 
commitments of water resources beyond perennial yield may result in 
detrimental impacts to habitats for some of the petitioned subspecies 
in the designated basins. When groundwater extraction exceeds aquifer 
recharge, it may result in surface water level decline, spring drying 
and degradation, or the loss of aquatic habitat (Zektser et al. 2005, 
pp. 396-397).
    Determining whether groundwater development is a threat to springs, 
streams or wetlands or not depends upon: (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) 
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) springs, streams or 
wetlands are too far away from proposed pumping projects to be impacted 
(Welch et al. 2007, pp. 71-79). Specific information on water 
development impacts pertaining to a particular petitioned subspecies is 
included in specific subspecies sections below as appropriate.
Agriculture
    The petition provides a general discussion of butterfly use of 
agricultural areas. It claims that agricultural practices are 
eliminating suitable habitat, resulting in losses of butterfly species. 
Fleishman et al. (1999, pp. 214-215) is referenced as stating 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

[[Page 61536]]

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 claims that agriculture is a threat to some of the 
petitioned subspecies, but it does not present specific information to 
support the claim that this potential threat is impacting the 
petitioned subspecies, their host plants, or nectar sources, or is 
likely to in the future. The petition does not present information 
regarding which types of agricultural practices may be threats, nor is 
information presented concerning past, present, or projected acreage or 
intensity of these operations in or near occupied or suitable 
locations. The petition also does not report loss of populations or 
reduction in numbers of these butterfly subspecies related directly to 
agricultural practices. We have little to no information in our files 
related to agricultural practices impacting the petitioned subspecies. 
Specific information on agriculture pertaining to a particular 
subspecies is included in specific subspecies sections below as 
appropriate.
Pesticide Use
    The petition claims that pesticide use is a threat to the 
petitioned butterfly subspecies (WildEarth Guardians 2010, p. 7). Use 
of pesticides (including drift) can impact butterfly habitat by killing 
butterfly nectaring and host plant species (Selby 2007, pp. 3, 30). 
This threat can be serious for those species that specialize in one 
host plant species (WildEarth Guardians 2010, p. 7). Use of 
insecticides on pastureland or croplands adjacent to butterfly habitat 
can be a direct threat to butterfly survival (Selby 2007, p. 30).
    The petition does not present any specific supporting information 
that this potential threat may be impacting the subspecies or is likely 
to in the future. The petition does not present specific information 
concerning past, present, or projected intensity of pesticide use in or 
near occupied or suitable locations. The petition does not present 
specific information as to whether this potential threat has, is, or is 
likely to affect the subspecies, their host plants, or nectar sources. 
The petition also does not report loss of populations or reductions in 
numbers of these subspecies to pesticide use. We have no information in 
our files related to pesticide use impacting any of the petitioned 
subspecies or their habitats. Specific information regarding pesticide 
use and impacts to a particular petitioned subspecies is included in 
specific subspecies sections below as appropriate.
Livestock Grazing
    The petition states that livestock grazing in general impacts 
riparian areas, wetlands, seeps, and springs by removing native 
vegetation, and by reducing cover, biomass, and the productivity of 
herbaceous and woody species. It also claims that trampling by 
livestock destroys vegetation and compacts the soil, increasing erosion 
and runoff, and that grazing spreads nonnative plant species (Fleishner 
1994, pp. 631-635; Belsky et al. 1999, pp. 8-11; Sada et al. 2001, p. 
15). Inappropriate livestock grazing can also trample butterfly larvae 
and 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). The petition indicates that 
light or moderate grazing can assist in maintaining butterfly habitats 
(WildEarth Guardians 2010, p. 23), but heavy grazing is considered 
incompatible with the conservation of some butterflies (Sanford 2006, 
p. 401; Selby 2007, pp. 3, 29, 33, 35).
    The petition indicates that the threat from livestock grazing is 
occurring over widespread general habitat areas where the petitioned 
subspecies could be occurring, with a few site-specific instances. The 
petition provides little to no specific supporting information to 
indicate this potential threat may be impacting the petitioned 
subspecies or is likely to in the future. The petition provides little 
to no information related to the level of grazing utilization that has 
or may be occurring at occupied or suitable locations, or that it may 
increase in intensity in the future. The petition does not present 
information that indicates the degree, if any, that invasive plants are 
spreading in the petitioned subspecies' occupied habitats as a result 
of grazing activities. The petition does not report loss of populations 
or reduction in numbers of these petitioned subspecies due to livestock 
grazing. We have little to no information available in our files 
related to livestock grazing impacting the petitioned subspecies. 
Specific information related to livestock grazing and impacts to a 
particular subspecies is included in specific subspecies sections below 
as appropriate.
Climate Change
    The petition claims that climate change in the Great Basin is a 
threat to the petitioned subspecies. The average temperature in the 
Great Basin has increased 0.6 to 1.1 degrees Fahrenheit (0.3 to 0.6 
degrees Celsius) during the last 100 years (Chambers 2008a, p. 29) and 
is expected to increase by 3.6 to 9 degrees Fahrenheit (2 to 5 degrees 
Celsius) over the next century (Cubashi et al. 2001 cited by Chambers 
2008a, p. 29).
    The petition indicates that climate change is expected to affect 
the timing and flow of streams, springs, and seeps in the Great Basin 
(Chambers 2008b, p. 20) which support the moist meadows upon which some 
petitioned 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 2008a, p. 29). Potential changes in 
the bloom date of meadow plants used by butterflies due to climate 
change could affect their use (WildEarth Guardians 2010, p. 9). The 
petition indicates that 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 
(CO2) may favor invasion of annual grasses such as the 
nonnative Bromus tectorum (cheat grass) (Smith et al. 2000, pp. 79, 
81). Increased temperatures and CO2 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).
    According to Loarie et al. (2009, p. 1052), as referenced in the 
petition, species and ecosystems will need to shift northward an 
average of 0.3 mile (mi) (0.42 kilometer (km)) per year to avoid the 
effects of increasing temperatures associated with climate change. 
Loarie et al. (2009, p. 1053) also states 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 states that it is unlikely that small, 
isolated populations of butterflies in the Great Basin, dependent on 
reduced

[[Page 61537]]

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). Species and habitats already stressed 
by other factors may be less able to cope with climate change 
(WildEarth Guardians 2010, p. 10). The petition did not provide climate 
change or drought information specific to Nevada or California, or the 
general areas known to be occupied by any of the 10 petitioned 
butterflies, or on the specific detrimental effects of climate change 
or drought to each subspecies.
    Based on information in our files, 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 (United States Environmental Protection Agency 1998, pp. 1-4; 
Chambers and Pellant 2008, pp. 29-33).
    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). Thus, while the 
information in the petition and our files indicates that climate change 
has the potential to affect vegetation and habitats used by butterflies 
in the Great Basin in the long term, there is much uncertainty 
regarding which habitat attributes could be affected, and the timing, 
magnitude, and rate of their change as it relates to the 10 petitioned 
butterflies. Specific information pertaining to climate change and a 
particular petitioned subspecies is included in specific subspecies 
sections below as appropriate.
Factor B. Overutilization for Commercial, Recreational, Scientific, or 
Educational Purposes
    The petition states that individuals of all of the petitioned 
butterfly subspecies have been collected by scientists and amateur 
collectors over the years, but it is not known whether collection is a 
threat to any of the subspecies as a whole (WildEarth Guardians 2010, 
p. 8). The petition does not provide information that overutilization 
has led to the loss of butterfly populations or a significant reduction 
in numbers of individuals for any of the petitioned butterflies.
    We do not have information in our files to suggest overutilization 
as a threat to any of the petitioned subspecies. This discussion 
provides the basis for our determinations in specific subspecies 
sections below.
Factor C. Disease or Predation
    The petition indicates that disease is not known to be a threat to 
any of the petitioned butterflies (WildEarth Guardians 2010, p. 8). A 
general statement is made in the petition that larvae and adult 
butterflies are subject to predation from a variety of wildlife; 
however, it is not known whether predation is a threat to any of the 
petitioned subspecies (WildEarth Guardians 2010, p. 8).
    We do not have information in our files suggesting disease or 
predation as a threat to the petitioned butterfly subspecies. This 
discussion provides the basis for our determinations in specific 
subspecies sections below.
Factor D. The Inadequacy of Existing Regulatory Mechanisms
    The petition considers the inadequacy of existing regulatory 
mechanisms to be a threat for all 10 petitioned subspecies (WildEarth 
Guardians 2010, p. 40). The petition claims that no Federal or State 
programs exist to manage sensitive invertebrate species in Nevada or 
the Great Basin, but it does not address existing regulatory mechanisms 
in California (WildEarth Guardians 2010, p. 8). Information provided in 
the petition's referenced material suggests that the general habitats 
that could be used by the petitioned subspecies may occur on lands 
under various combinations of private, State, tribal, and Federal 
management. The petition presents little to no specific information to 
support the claim that potential threats are associated with inadequate 
existing regulatory mechanisms, nor does the petition connect 
inadequate existing regulatory mechanisms by Bureau of Land Management 
(BLM) or other Federal agencies to impacts to or losses of populations 
or declining population trends of the petitioned subspecies.
    All of the petitioned butterfly subspecies, with the exception of 
the Carson Valley wood nymph and Railroad Valley skipper (Hesperia 
uncas reeseorum), are included under the referenced 2007 BLM list of 
sensitive species (BLM 2007a, pp. J6-J7, J37). In 2008, BLM policy and 
guidance for species of concern occurring on BLM-managed land was 
updated under BLM's 6840 Manual, ``Special Status Species Management'' 
(BLM 2008a). 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 2008a, p. 3). Inclusion 
as a BLM sensitive species does provide consideration of conservation 
measures for the subspecies under the National Environmental Policy 
Act.
    Based on information presented in the petition and available in our 
files, Nevada does not have the ability to protect invertebrates under 
its current State law. The Nevada Department of Wildlife is limited in 
its ability to protect insects under its current regulations (Nevada 
Revised Statutes (NRS)). Nevada State law protects species that the 
Wildlife Commission determines to be imperiled (NRS 503.585 cited in 
WildEarth Guardians 2010, p. 8). While some invertebrates such as 
mollusks and crustaceans may be protected because they can be 
classified under wildlife (NRS 501.110 cited in WildEarth Guardians 
2010, p. 8), butterflies are not covered under this statute (WildEarth 
Guardians 2010, p. 8). No butterfly species are currently protected by 
State law in Nevada (Nevada Administrative Code 503.020-503.080). The 
California Department of Fish and Game is unable to protect insects 
under its current regulations (P. Bontadelli, in litt., 1990).
    The petition presents little to no specific information supporting 
the claim that threats are associated with inadequate existing 
regulatory mechanisms. Additionally, the petition provides little to no 
specific supporting information to associate losses of butterfly 
populations or declining population trends to inadequate existing 
regulatory mechanisms by State wildlife agencies or other State 
agencies.
    We have little to no information available in our files to suggest 
that inadequacy of existing regulatory mechanisms may be threatening 
the petitioned subspecies. For most of these subspecies, we have no 
information in our files related to this potential threat; however, for 
a few there is some

[[Page 61538]]

information in our files to suggest a potential threat due to the 
inadequacy of existing regulatory mechanisms. Specific information 
pertaining to the inadequacy of existing regulatory mechanisms and a 
particular subspecies is included in specific subspecies sections below 
as appropriate.
Factor E. Other Natural or Manmade Factors Affecting its Continued 
Existence
    The petition states that all of the petitioned butterflies may be 
susceptible to the effects of biological vulnerability, which may 
increase the likelihood of extinction (WildEarth Guardians 2010, pp. 6, 
10). 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). The petition further asserts that many of the butterflies 
included in the petition occur as single populations or a few disparate 
ones, and that the number of populations may be more important than 
population size when assessing the status of a butterfly (Sanford 2006, 
p. 401). Some of the petitioned butterflies occur in isolated 
populations in patchy environments (WildEarth Guardians 2010, p. 11), 
and the 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). 
Overall, the petition provides little information related to the 
distribution, numbers of populations, size of populations, or 
population trends for the 10 petitioned butterfly subspecies. However, 
the petition and its references indicate that most of the 10 subspecies 
are known to have more than one population. The petition provides 
little to no specific information that indicates that biological 
vulnerability may be a threat to any of the petitioned subspecies.
    General biological information in our files indicates that 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 distribution and small population 
numbers or sizes are considered in determining whether the petition 
provides substantial information regarding a natural or anthropogenic 
threat, or a combination of threats, that 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 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).
    We have little to no additional information related to the overall 
abundance, distribution, number and size of populations, or population 
trends for any of the 10 subspecies in our files. We do not have 
additional information in our files related to biological vulnerability 
as a threat to any of the petitioned butterfly subspecies. Specific 
information pertaining to biological vulnerability and a particular 
subspecies is included in specific subspecies sections below as 
appropriate.

Species for Which Substantial Information Was Not Presented

    In this section, the butterfly subspecies are listed in 
alphabetical order by their common name.
Carson Valley silverspot (Speyeria nokomis carsonensis)
    We accept the characterization of the Carson Valley silverspot as a 
valid subspecies based on its description by Austin (1998c, pp. 573-
574). The Carson Valley silverspot's larval host plant is the violet, 
Viola nephrophylla (Austin et al. 2000, p. 2; Austin and Leary 2008, p. 
97), and the primary nectar sources are Cirsium sp. (Austin et al. 
2000, p. 2). A single brood flies during mid-July to mid-October 
(Austin 1998c, p. 574; Austin et al. 2000, p. 2).
    The Carson Valley silverspot occurs in wet meadows along the east 
side of the Carson Range from southern Washoe County, Nevada, south to 
northern Alpine County, California. It occurs along the Carson River 
drainage in Douglas County, Nevada, and Alpine County, California. It 
also occurs in the Pine Nut Mountains of Douglas County, Nevada, and 
the Sweetwater Mountains (Austin 1998c, p. 574; Austin et al. 2000, p. 
2; The Nature Conservancy 2009, p. 1), Pine Grove Hills, and Smith 
Valley of Lyon County, Nevada (Austin and Leary 2008, p. 97). 
Populations have been found along the Walker River drainage in Mono 
County, California (Austin et al. 2000, p. 2; The Nature Conservancy 
2009, p. 1). The largest known colony occurs at Scossa Ranch, Douglas 
County, Nevada (Austin et al. 2000, p. 2). The subspecies has been 
documented from the Carson Range North, Washoe County; Snow Valley, 
Carson City County; and Mineral Valley, Pine Nut Creek, and Sugar Loaf, 
Douglas County (NNHP 2006, pp. 21-22, 36-37). The petition indicates 
there are 13 Nevada occurrences in the NNHP (NNHP 2009, p. 8) database, 
but location information is not indicated. However, review of the 
complete Nevada database, which we have in our files, includes 
additional locations at Davis Creek Park, Kingsbury Grade, Thompson 
Canyon, Dangberg Reservoir near Gardnerville, Daggett Pass, Veceey 
Canyon area, Haines Canyon, Thomas Creek, and Kings Canyon (NNHPD 
2008). The petition notes that this subspecies may currently occur at 
37 sites (M. Sanford, pers. comm., cited in WildEarth Guardians 2010, 
p. 18), but location information was not provided. The petition states 
that the subspecies is reduced from historical abundance (M. Sanford 
pers. comm., cited in WildEarth Guardians 2010, p. 17).

    Factor A:
Information Provided in the Petition
    The petition asserts that water development; land development; 
agriculture; livestock grazing; nonnative plant species invasion, such 
as by Lepidium latifolium (tall whitetop); and pesticide use may impact 
this subspecies (WildEarth Guardians 2010, p. 19). The petition 
indicates that these types of activities can eliminate, degrade, and 
fragment butterfly habitat (WildEarth Guardians 2010, p. 19). The 
petition adds that heavy livestock grazing on public and private land 
in the Sierra Nevada, Pine Nut Mountains, and Sweetwater Mountains has 
degraded habitat for the Carson Valley silverspot (WildEarth Guardians 
2010, p. 20). The annual grazing removes vegetation from seep- and 
spring-fed meadows, and water diversions for grazing have dried up 
meadows, eliminating silverspot habitat (WildEarth Guardians 2010, p. 
20). The petition mentions that climate change may result in the drying 
out of moist habitats in the Carson Valley (WildEarth Guardians 2010, 
p. 20).
    According to the petition, most of the Carson Valley silverspot 
populations occur in habitats associated with the Carson River and its 
tributaries in ``Carson Valley'' (WildEarth Guardians 2010, p. 18). The 
petition indicates that the NNHP has ranked the Carson River among the 
26 highest priority wetland areas in the State (NNHP 2007, p. 8).

[[Page 61539]]

Many other associated areas, including tributaries, riparian areas, wet 
meadows, marshes, ponds, and ephemeral pools in Carson Valley, Nevada, 
are also listed (NNHP 2007, pp. 12-14). According to NNHP (2007, p. 36) 
and The Nature Conservancy (2008, p. 31), numerous areas associated 
with these sites and others along the Middle Carson River have been 
degraded or converted to other lands uses. Moderate to high stressors 
impacting these areas in Carson Valley include water development and 
diversions, groundwater pumping, hydrogeomorphic modification, land 
development, agriculture, livestock grazing, recreation, fire 
suppression, wetland leveling, and nonnative species invasions. The 
petition implies these activities are negatively impacting the Carson 
Valley silverspot.
Evaluation of Information Provided in the Petition and Our Files
    The petition does not provide specific, supporting information to 
indicate that the Carson Valley silverspot may be impacted from water 
development, land development, agriculture, livestock grazing, 
nonnative plant species invasion, pesticide use, or climate change at 
occupied locations in Nevada or California. The petition does not 
provide additional information or discussion regarding possible impacts 
to the Carson Valley silverspot from recreation, fire suppression, and 
wetland leveling. The petition does not provide specific, supporting 
information regarding past, present, or future conditions of these 
threats or their scope, immediacy, or intensity at occupied or suitable 
habitats in Nevada or California. The petition emphasizes habitat 
impacts along the Middle Carson River in Nevada; however, there are a 
number of populations located in several counties in both Nevada and 
California. Little to no information regarding habitat impacts to these 
additional populations is indicated. We have information in our files 
that indicate habitat disturbances such as water table changes may 
adversely impact larval food availability (Austin et al. 2000, p. 2), 
but details are not provided. Grazing has been associated with 
population declines (M. Sanford, pers. comm., cited in WildEarth 
Guardians 2010, p. 19), but details are not provided. We do not have 
any further specific, supporting information in our files regarding 
potential threats or resulting negative impacts to Carson Valley 
silverspot populations in Nevada or California. Also see the ``Summary 
of Common Threats'' section for information pertaining to water 
development, agriculture, livestock grazing, pesticide use, and climate 
change as potential threats.
    While the petition reports losses of Carson Valley silverspot 
populations from their historical abundance (M. Sanford, pers. comm., 
cited in WildEarth Guardians 2010, p. 17), which could suggest a 
negative response to these potential threats, details regarding these 
losses and the reason(s) for them are not provided. The petition does 
not present specific information related to population numbers, size, 
or trends for the Carson Valley silverspot over any period of time. The 
petition does not provide additional information related to the 
reported population declines, regarding their locations, number of 
populations, or magnitude of them. We do not have this information in 
our files. As a result, it is not possible to put these reported 
declines into context to determine whether populations of the Carson 
Valley silverspot may be experiencing declines or not or their possible 
severity. These declines might 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).
    Based on our evaluation of the information provided in the petition 
and in our files, we have determined that the petition does not present 
substantial information to indicate that listing the Carson Valley 
silverspot may be warranted due to the present or threatened 
destruction, modification, or curtailment of its habitat or range.

    Factors B and C:
Information Provided in the Petition
    The petition states that it is unknown whether overutilization, 
disease, or predation are threats to this subspecies (WildEarth 
Guardians 2010, p. 8). Based on information referenced in the petition, 
numerous individuals (432 males, 224 females) of this subspecies have 
been collected by several collectors between 1964 and 1989 at Scossa 
Ranch, Douglas County, Nevada (Austin 1998c, p. 574). Based on these 
total numbers over the 25-year time period, an average of 17 males and 
9 females were collected per year. Ranges of individuals collected 
during a single day in a particular year were 1 to 39 for males and 1 
to 54 for females. In some years, multiple collections occurred, and in 
some years collections occurred on consecutive days (Austin 1998c, p. 
574).
Evaluation of Information Provided in the Petition and Our Files
    The petition does not provide information that overutilization, 
disease, or predation has negatively impacted the subspecies. We have 
no information in our files related to overutilization, disease, or 
predation for this subspecies. According to Austin et al. (2000, p. 2), 
Scossa Ranch remains the largest known colony for this subspecies. As 
indicated earlier, there are also multiple populations of this 
subspecies occurring elsewhere in Nevada and California. We do not know 
if or to what extent these other populations have been impacted by 
collection efforts. The available information does not indicate 
collection efforts are negatively impacting the Carson Valley 
silverspot. Also see the ``Summary of Common Threats'' section for 
information pertaining to overutilization, disease, and predation as 
potential threats.
    Based on our evaluation of the information provided in the petition 
and in our files, we have determined that the petition does not present 
substantial information to indicate that listing the Carson Valley 
silverspot may be warranted due to Factor B (overutilization for 
commercial, recreational, scientific, or educational purposes) or 
Factor C (disease or predation).

    Factor D:
Information Provided in the Petition
    The petition asserts that inadequate existing regulatory mechanisms 
are a threat to this subspecies (WildEarth Guardians 2010, pp. 8, 40). 
This butterfly is listed as a BLM sensitive species (BLM 2007a, p. J6). 
This designation can offer it some conservation consideration. The 
petition also indicates that some populations of the Carson Valley 
silverspot, as well as potential habitat, occur on properties covered 
by conservation easements (WildEarth Guardians 2010, p. 19). These 
easements may be protected from land development, but they are not 
protected from other activities such as groundwater pumping, invasive 
species, livestock grazing, and agricultural use (WildEarth Guardians 
2010, p. 19).
Evaluation of Information in the Petition and Our Files
    The petition does not provide specific information to support the 
assertion that existing regulatory mechanisms are inadequate to protect 
the subspecies from potential threats because it does not provide 
substantial information to support their assertion that threats are

[[Page 61540]]

occurring under the other factors. The petition does not connect 
inadequate existing regulatory mechanisms to losses of Carson Valley 
silverspot populations or declining population trends. We do not have 
information in our files related to the inadequacy of existing 
regulatory mechanisms for this subspecies. Also see the ``Summary of 
Common Threats'' section for information pertaining to the inadequacy 
of regulatory mechanisms as a potential threat.
    Based on our evaluation of the information provided in the petition 
and in our files, we have determined that the petition does not present 
substantial information to indicate that listing the Carson Valley 
silverspot may be warranted due to the inadequacy of existing 
regulatory mechanisms.

    Factor E:
Information Provided in the Petition
    The petition indicates that this subspecies may be vulnerable to 
reduced population numbers (WildEarth Guardians 2010, p. 40) due to the 
observed subspecies' reduction in numbers from historical abundance (M. 
Sanford pers. comm., cited in WildEarth Guardians 2010, p. 17).
Evaluation of Information in the Petition and Our Files
    The petition did not present, nor do we have, specific information 
in our files related to population numbers, size, or trends for the 
Carson Valley silverspot. The petition does not provide additional 
information related to the reported population declines, regarding the 
location, number of populations, magnitude of declines, or reasons for 
them. The petition does not provide information on chance events or 
other threats to the subspecies and connect them to small population 
numbers or size, or the potential for such threats to occur in occupied 
habitats in the future. Since this subspecies is distributed over a 
number of populations in two States, its extinction vulnerability due 
to stochastic events may be reduced. In the absence of specific 
information and connection, we do not consider small population numbers 
alone to be a threat to this subspecies. Also see the ``Summary of 
Common Threats'' section for information pertaining to small population 
size as a potential threat.
    Based on evaluation of the information provided in the petition and 
our files, we have determined that the petition does not present 
substantial information to indicate that listing the Carson Valley 
silverspot may be warranted due to other natural or manmade factors 
affecting the subspecies' continued existence.
Carson Valley Wood Nymph (Cercyonis pegala carsonensis)
    We accept the characterization of the Carson Valley wood nymph as a 
valid subspecies, based on its description by Austin (1992, pp. 10-11). 
The larval host plant is a grass or sedge species (Austin et al. 2000, 
p. 1). Adults nectar on a variety of white and yellow flowers from the 
families Apiaceae (carrot) and the Asteraceae (sunflower) (Austin 1992, 
p. 11). The single brood flies from early July to early September 
(Austin 1992, p. 11).
    The Carson Valley wood nymph occurs in marshes of the western Great 
Basin along the base of the Carson Range, especially in Carson Valley 
from Carson City, Nevada, south to east-central Alpine County, 
California, and the Gardnerville area of Douglas County, Nevada, with a 
few northern specimens from the Reno area, Washoe County, Nevada 
(Austin 1992, p. 11). Austin et al. (2000, p. 1) mention unidentified 
localities in Lyon County, Nevada. The petition indicates there are 14 
Nevada occurrences recorded in the NNHP database, but occurrence 
locations are not identified (NNHP 2009, p. 6). However, review of the 
complete Nevada database, which we have in our files, shows additional 
locations near Minden, Daggett Pass, Centerville, Genoa, and along the 
Carson River, with Cradlebaugh Bridge being a named location (NNHPD 
2008). The largest colony occurs at Scossa Ranch, Douglas County 
(Austin et al. 2000, p. 1). According to the petition, populations 
appear to be declining between 10 to 30 percent in the short term with 
possible extirpation of populations in Washoe County (NatureServe 
2009c, p. 2). Surveys conducted between 2001 and 2006 showed that some 
populations of the Carson Valley wood nymph have been extirpated (M. 
Sanford, pers. comm., cited in WildEarth Guardians 2010, p. 22).

    Factor A:
Information Provided in the Petition
    The petition asserts in general that water development; land 
development; agriculture; livestock grazing; invasion by nonnative 
plant species, such as Lepidium latifolium; and pesticide use may 
adversely affect Carson Valley wood nymph habitat (WildEarth Guardians 
2010, pp. 22-23, 40). The petition indicates that these types of 
actions can eliminate, degrade, and fragment butterfly habitat 
(WildEarth Guardians 2010, p. 23). Threats mentioned by other sources 
pertaining specifically to this subspecies include land development, 
overgrazing, and lowering of the water table (NatureServe 2009c, p. 2).
    The petition indicates that the NNHP (2007, pp. 8, 12-14) has 
ranked the Carson River in Nevada among the 26 highest priority wetland 
areas in the State, and many associated areas--including tributaries, 
riparian areas, wet meadows, marshes, ponds, and ephemeral pools in 
Carson Valley, Nevada--are also included. According to NNHP (2007, p. 
36) and The Nature Conservancy (2008, p. 31), numerous areas associated 
with these habitats and others along the Middle Carson River have been 
degraded or converted to other land uses, and moderate to high 
stressors impacting these areas include water development and 
diversions, groundwater pumping, hydrogeomorphic modification, land 
development, agriculture, livestock grazing, recreation, fire 
suppression, wetland leveling, and nonnative species invasion.
Evaluation of Information in the Petition and Our Files
    The petition does not provide specific, supporting information to 
indicate the Carson Valley wood nymph may be impacted from water 
development, land development, agriculture, livestock grazing, invasive 
plants, or pesticide use at occupied locations in Nevada or California. 
The petition does not provide additional information or discussion 
regarding possible impacts to the Carson Valley wood nymph from 
recreation, fire suppression, and wetland leveling. The petition does 
not provide specific, supporting information regarding past, present, 
or future conditions of these threats or their scope, immediacy, or 
intensity at occupied or suitable habitats in Nevada or California. The 
petition emphasizes habitat impacts along the Middle Carson River in 
Nevada; however, there are additional Carson Valley wood nymph 
populations located in several counties in both Nevada and California. 
No information is included to indicate habitat impacts to these 
additional populations. We have information in our files (Austin et al. 
2000, p. 1) indicating, in general, that land development, overgrazing, 
and lowering of the water table could reduce or destroy habitat of the 
Carson Valley wood nymph, but further details are not provided. We do 
not have any further specific, supporting information in our files 
regarding other potential impacts or resulting adverse impacts to 
Carson Valley wood nymph populations in Nevada or California. Also see 
the

[[Page 61541]]

``Summary of Common Threats'' section for information pertaining to 
water development, agriculture, livestock grazing, and pesticide use as 
potential threats.
    While the petition reports a loss of Carson Valley wood nymph 
populations with some possible extirpations (M. Sanford, pers. comm., 
cited in WildEarth Guardians 2010, p. 22), which could suggest a 
negative response to these potential threats, details regarding these 
losses and the reasons for them are not provided. The petition does not 
present specific information related to population numbers, size, or 
trends for the Carson Valley wood nymph over any period of time, 
including the 2001 to 2006 period. The petition does not provide 
additional information related to the reported population declines, 
regarding their locations, number of populations, or the magnitude of 
them. The context for the reported 10 to 30 percent decline between 
2001 and 2006 is not clear as we do not know how many populations this 
range should apply or whether it is over the entire 5-year period or a 
portion of it. The identification of the possibly extirpated 
populations, their locations in Nevada or California, or the number of 
them are not provided. We do not have this information in our files. As 
a result, it is not possible to put these reported declines or 
extirpations into context to determine whether populations of the 
Carson Valley wood nymph may be experiencing declines or not or their 
possible severity. These declines might 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).
    Based on our evaluation of the information provided in the petition 
and in our files, we have determined that the petition does not present 
substantial information to indicate that listing the Carson Valley wood 
nymph may be warranted due to the present or threatened destruction, 
modification, or curtailment of its habitat or range.

    Factors B and C:
Information Provided in the Petition
    The petition states that it is unknown if overutilization, disease, 
or predation are threats to this subspecies. Austin (1992, p. 11) 
reports numerous individuals (475 males, 428 females) of this 
subspecies were collected by several individuals between 1964 and 1989 
at Scossa Ranch, Douglas County, Nevada, as referenced in the petition. 
Based on these total numbers over the 25-year time period, an average 
of 19 males and 17 females were collected per year. Ranges of 
individuals collected during a single day in a particular year were 1 
to 108 for males and 1 to 80 for females. In some years, multiple 
collections occurred, and in some years collections occurred on 
consecutive days (Austin 1992, p. 11).
Evaluation of Information in the Petition and Our Files
    The petition does not provide information that overutilization, 
disease, or predation has negatively impacted the subspecies. We do not 
have information in our files related to overutilization, disease, or 
predation for this subspecies. According to Austin et al. (2000, p. 1), 
Scossa Ranch remains the largest known colony for this subspecies. As 
indicated earlier, there are also multiple populations of this 
subspecies occurring elsewhere in Nevada and California. We do not know 
if or to what extent these other populations have been impacted by 
collection efforts. The available information does not indicate that 
collection efforts are negatively impacting the Carson Valley wood 
nymph. Also see the ``Summary of Common Threats'' section for 
information pertaining to overutilization, disease, and predation as 
potential threats.
    Based on our evaluation of the information provided in the petition 
and our files, we have determined that the petition does not present 
substantial information to indicate that listing of the Carson Valley 
wood nymph may be warranted due to Factor B (overutilization for 
commercial, recreational, scientific, or educational purposes) or 
Factor C (disease or predation).

    Factor D:
Information Provided in the Petition
    The petition asserts that existing regulatory mechanisms are 
inadequate to protect this subspecies (WildEarth Guardians 2010, pp. 8, 
40). The petition also indicates that most of the known or potential 
populations of the Carson Valley wood nymph do not occur on properties 
covered by conservation easements (WildEarth Guardians 2010, p. 23). 
While land under a conservation easement may be protected from land 
development, the area may not necessarily be protected from other 
activities such as groundwater pumping, invasive species, livestock 
grazing, and agricultural use (WildEarth Guardians 2010, p. 22). The 
petition states that the Carson Valley wood nymph is a BLM sensitive 
species (WildEarth Guardians 2010, p. 22); however, upon review, it is 
not included in the referenced document (BLM 2007a).
Evaluation of Information in the Petition and Our Files
    The petition does not provide specific information to support the 
assertion that existing regulatory mechanisms are inadequate to protect 
the subspecies from potential threats because it does not provide 
substantial information to support their assertion that threats are 
occurring under the other factors. The petition does not connect 
inadequate existing regulatory mechanisms to losses of Carson Valley 
wood nymph populations or declining population trends. We do not have 
information in our files related to the inadequacy of existing 
regulatory mechanisms for this subspecies. Also see the ``Summary of 
Common Threats'' section for information pertaining to the inadequacy 
of regulatory mechanisms as a potential threat.
    Based on our evaluation of the information provided in the petition 
and in our files, we have determined that the petition does not present 
substantial information to indicate that listing the Carson Valley wood 
nymph may be warranted due to the inadequacy of existing regulatory 
mechanisms.

    Factor E:
Information Provided in the Petition
    The petition indicates that this subspecies may be vulnerable to 
small populations (WildEarth Guardians 2010, pp. 21, 40) due to the 
possible decline and extirpations of Carson Valley wood nymph 
populations (M. Sanford, pers. comm., cited in WildEarth Guardians 
2010, p. 22).
Evaluation of Information in the Petition and Our Files
    The petition does not present additional information about the 
surveys conducted between 2001 and 2006, such as the locations, 
numbers, or causes of these presumed extirpations. We do not have 
information in our files related to population numbers, sizes, or 
trends. The petition does not provide information on chance events or 
other threats to the subspecies, nor does it connect these factors to 
small population numbers or size, or the potential for such chance 
events to occur in occupied habitats in the future. In the absence of 
this information and connection, we do not consider small population 
numbers alone to be a threat to this subspecies. Since the information 
indicates this subspecies is distributed over more than one population 
in two States, its vulnerability to extinction

[[Page 61542]]

due to stochastic events may be reduced. Also see the ``Summary of 
Common Threats'' section for information pertaining to small population 
size as a potential theat.
    Based on our evaluation of the information provided in the petition 
and our files, we have determined that the petition does not present 
substantial information to indicate that listing the Carson Valley wood 
nymph may be warranted due to other natural or manmade factors 
affecting the subspecies' continued existence.
Mattoni's Blue Butterfly (Euphilotes pallescens mattonii)
    We accept the characterization of Mattoni's blue butterfly as a 
valid subspecies based on its initial description by Shields (1975, p. 
20) and its subsequent reclassification as indicated by Austin (1998a, 
p. 633). This subspecies' host plant, Eriogonum microthecum var. 
laxiflorum (slender buckwheat), flowers between June and October 
(Shields 1975, pp. 20-21). Adults fly during July (Shields 1975, p. 20; 
Austin and Leary 2008, p. 76). Female Euphilotes lay their eggs on 
young flowers of Erigonum sp., and the larvae feed on pollen and later 
developing seeds (Pratt 1994, p. 388).
    Mattoni's blue butterfly is known from the west fork of Beaver 
Creek (Shields 1975, p. 20), west of Charleston Reservoir (Austin 
1998a, p. 633; Nevada Natural Heritage Program Database (NNHPD) 2008), 
west of Pequop Summit (Austin and Leary 2008, p. 76; NNHPD 2008), and 
the Pilot-Thousand Springs, Long-Ruby Valleys, and Bruneau River 
watersheds in Elko County, Nevada (NNHPD 2008; NatureServe 2009a, p. 
2). Shields (1975, p. 21) stated that since the host plant was common 
between 5,000 and 10,500 ft (1,524 to 3,200 m) in elevation in the 
western United States, Mattoni's blue butterfly may be more widespread 
than was known at that time. Austin et al. (2000, p. 3) indicate that 
this subspecies is ``apparently rare where it is found * * *.''

    Factor A:
Information Provided in the Petition
    The petition asserts that land use, livestock grazing and 
trampling, and climate change may affect this subspecies' habitat 
(WildEarth Guardians 2010, pp. 25, 40). The petition also states that 
land use and other factors could hinder dispersal (WildEarth Guardians 
2010, p. 25).
Evaluation of Information Provided in the Petition and in Our Files
    The petition provides no specific supporting information to 
indicate that Mattoni's blue butterfly is or may become impacted from 
land use, livestock grazing or trampling, or dispersal problems at any 
of its occupied sites in Elko County. The petition does not provide 
specific supporting information how climate change is or may impact 
this subspecies or its habitat. The petition does not provide 
supporting information regarding past, present, or future conditions of 
these threats or their scope, immediacy, or intensity at occupied or 
suitable habitats. The petition does not report loss of populations or 
reduction in numbers of this butterfly subspecies which could suggest a 
negative response to threats such as those claimed. Although we have a 
letter from a contractor indicating that any habitat disturbance could 
theoretically adversely affect this subspecies (Austin et al. 2000, p. 
3), we do not have specific information in our files to support the 
assertion that land use, livestock grazing or trampling, or climate 
change is impacting Mattoni's blue butterfly populations. Evaluation of 
the available information indicates that there is not sufficient 
evidence to suggest that these potential threats are occurring in 
occupied areas to the extent that they may be affecting this 
subspecies' status such that it may warrant listing under the Act. Also 
see the ``Summary of Common Threats'' section for information 
pertaining to livestock grazing and climate change as potential 
threats.
    Based on our evaluation of the information provided in the petition 
and in our files, we have determined that the petition does not present 
substantial information to indicate that listing Mattoni's blue 
butterfly may be warranted due to the present or threatened 
destruction, modification, or curtailment of its habitat or range.

    Factors B and C:
Information Provided in the Petition
    The petition states that it is not known whether overutilization, 
disease, or predation are threats to this subspecies (WildEarth 
Guardians 2010, p. 8). Information referenced in the petition indicates 
that one female and one male are known to have been collected in 1969 
(Austin 1998a, p. 633).
Evaluation of Information Provided in the Petition and in Our Files
    The petition does not provide information that overutilization, 
disease, or predation has negatively impacted the subspecies. We have 
no information in our files related to overutilization, disease, or 
predation for this subspecies. Also see the ``Summary of Common 
Threats'' section for information pertaining to overutilization, 
disease, and predation as potential threats.
    Based on our evaluation of the information provided in the petition 
and in our files, we have determined that the petition does not present 
substantial information to indicate that listing the Mattoni's blue 
butterfly may be warranted due to Factor B (overutilization for 
commercial, recreational, scientific, or educational purposes) or 
Factor C (disease, or predation).

    Factor D:
Information Provided in the Petition
    The petition asserts that inadequate existing regulatory mechanisms 
are a threat to the subspecies (WildEarth Guardians 2010, pp. 8, 40). 
Mattoni's blue butterfly is listed as a sensitive species by BLM (BLM 
2007a, p. J-7) which may offer some conservation consideration.
Evaluation of Information Provided in the Petition and in Our Files
    The petition does not provide information to support the assertion 
that existing regulatory mechanisms are inadequate to protect the 
subspecies from potential threats because it does not provide 
substantial information to support their assertion that threats are 
occurring under the other factors. The petition does not connect 
inadequate existing regulatory mechanisms to losses of Mattoni's blue 
butterfly populations or declining population trends. We do not have 
information in our files related to the inadequacy of existing 
regulatory mechanisms for this subspecies. Also see the ``Summary of 
Common Threats'' section for information pertaining to the inadequacy 
of existing regulatory mechanisms as a potential threat.
    Based on our evaluation of the information provided in the petition 
and in our files, we have determined that the petition does not present 
substantial information to indicate that listing Mattoni's blue 
butterfly may be warranted due to the inadequacy of existing regulatory 
mechanisms.

    Factor E:
Information Provided in the Petition
    The petition indicates that this subspecies may be vulnerable due 
to limited range (WildEarth Guardians

[[Page 61543]]

2010, pp. 10-11, 40). The petition asserts that Mattoni's blue 
butterfly may be restricted to its habitat in Elko County, Nevada 
(WildEarth Guardians 2010, p. 25). If the subspecies is dependent on 
its specific host plant, it may not be able to disperse far enough to 
other locations where the host plant can be found (Shields and Reveal 
1988, p. 80). The petition also indicates Austin et al. (2000, p. 3) 
said that this subspecies is ``apparently rare where it is found * * 
*.''
Evaluation of Information in the Petition and Our Files
    The petition does not present, nor do we have information in our 
files, related to population numbers, size, or trends for Mattoni's 
blue butterfly. The petition does not provide information on chance 
events or other threats to the subspecies and connect them to a 
possibly restricted range or small numbers for the subspecies or the 
potential for such chance events to occur in occupied habitats in the 
future. In the absence of specific information identifying threats to 
the subspecies and connecting them to a restricted geographic range or 
small numbers of the subspecies, or the potential for such events to 
occur in occupied habitats, we do not consider a restricted geographic 
range or rarity by themselves to be threats to this subspecies. Many 
naturally rare species have persisted for long periods within small 
geographic areas. The fact that a species is rare does not necessarily 
indicate that it may meet the definition of threatened or endangered 
under the Act. Also see the ``Summary of Common Threats section'' for 
information pertaining to limited distribution and small population 
size as potential threats.
    Therefore, based on our evaluation of the information provided in 
the petition and in our files, we have determined that the petition 
does not present substantial information to indicate that listing 
Mattoni's blue butterfly may be warranted due to other natural or 
manmade factors affecting the subspecies' continued existence.
Mono Basin Skipper (Hesperia uncas giulianii)
    We accept the characterization of the Mono Basin skipper as a valid 
subspecies based on its description by McGuire (1998, pp. 461-462). The 
Mono Basin skipper flies from May to mid-July (Austin and McGuire 1998, 
p. 780; Davenport et al. 2007, p. 8). Females lay their eggs on Stipa 
sp. (needlegrass) (McGuire 1998, p. 463).
    The type locality for the Mono Basin skipper is the Adobe Hills 
area in Mono County, California (McGuire 1998, p. 462). Habitat at the 
type locality for the Mono Basin skipper is described as gently rolling 
hills with sandy soil between 6,800 and 7,500 ft (2,072 and 2,286 m) in 
elevation (McGuire 1998, p. 462). The vegetation consists of Pinus 
monophylla (singleleaf pi[ntilde]on) woodlands and Great Basin 
sagescrub with Artemisia tridentata (big sagebrush), Chrysothamnus 
viscidiflorus (yellow rabbitbrush), Eriogonum umbellatum ssp. 
(sulphurflower buckwheat), Lupinus argenteus (silvery lupine), and 
Stipa sp., including Stipa pinetorum (pinewoods needlegrass). At least 
one population was described as using ``open, sparse sage flats'' 
(McGuire 1998, p. 462). Individuals were seen within this area at 
Granite and Glass Mountains; near Bodie; and near Laws (McGuire 1998, 
p. 462). McGuire (1998, p. 462) indicates this subspecies may occur 
elsewhere in similar Adobe Hills habitat. The Adobe Hills extend into 
western Mineral County, Nevada, where a similar skipper phenotype was 
discovered (Austin and McGuire 1998, p. 780; McGuire 1998, pp. 462-
463).

    Factor A:
Information Provided in the Petition
    The petition asserts that livestock grazing and its associated 
effects and climate change are threats to the subspecies (WildEarth 
Guardians 2010, pp. 28, 40). The petition also claims that unnatural 
fires that result from invasive plants spread by grazing eliminate 
shrub steppe habitat (WildEarth Guardians 2010, p. 28).
Evaluation of Information Provided in the Petition and in Our Files
    The petition does not provide specific supporting information that 
livestock grazing is impacting the Mono Basin skipper in the Adobe 
Hills. The petition does not provide any information that would 
indicate past, current, or future livestock grazing practices have, 
are, or may negatively impact the Mono Basin skipper or its habitat. We 
do not have additional information in our files related to livestock 
grazing in the Adobe Hills. The petition does not present, nor do we 
have in our files, any specific, supporting information that indicates 
invasive plants are spreading in the Adobe Hills and that unnatural 
fire is resulting from invasive plants or that unnatural fire is 
eliminating shrub-steppe habitat. The petition does not present, nor do 
we have in our files, specific supporting information related to 
impacts due to climate change for the Mono Basin skipper. The petition 
does not report loss of populations or reduction in numbers of this 
subspecies which could suggest a negative response to threats such as 
those claimed. Evaluation of the available information does not 
establish that these potential threats are occurring in occupied areas 
and may be impacting this subspecies. Also see the ``Summary of Common 
Threats'' section for information pertaining to livestock grazing and 
climate change as potential threats.
    Based on our evaluation of the information provided in the petition 
and in our files, we have determined that the petition does not present 
substantial information to indicate that listing the Mono Basin 
butterfly may be warranted due to the present or threatened 
destruction, modification, or curtailment of its habitat or range.

    Factors B and C:
Information Provided in the Petition
    The petition states that it is not known whether overutilization, 
disease, or predation are threats to this subspecies (WildEarth 
Guardians 2010, p. 8). Information referenced in the petition indicates 
that 17 males and 3 females are known to have been collected between 
1978 and 1986 (McGuire 1998, p. 462).
Evaluation of Information Provided in the Petition and in Our Files
    The petition does not provide information that overutilization, 
disease, or predation has negatively impacted the subspecies. While the 
petition's referenced material provides some information about known 
numbers of collections, the petition does not provide any information 
about the population sizes or trends during this time period. Given the 
low number of individuals collected over an 8-year time span, the 
length of time since these collections were made, and the lack of 
information about the relative impact to the population, the petition 
does not provide substantial information to indicate that collection 
may be a threat to the subspecies. We have no information in our files 
related to overutilization, disease, or predation for this subspecies. 
Also see the ``Summary of Common Threats'' section for information 
pertaining to overutilization, disease, and predation as potential 
threats.
    Based on our evaluation of the information provided in the petition 
and in our files, we have determined that the petition does not present 
substantial information to indicate that listing the Mono Basin skipper 
may be warranted due to Factor B (overutilization for commercial, 
recreational, scientific, or educational

[[Page 61544]]

purposes) or Factor C (disease or predation).

    Factor D:
Information Provided in the Petition
    The petition asserts that inadequate existing regulatory mechanisms 
are a threat to this subspecies (WildEarth Guardians 2010, pp. 8, 40). 
The BLM lists the Mono Basin skipper as a sensitive species in Nevada 
(where it is not known to occur) but not in California (where it is 
known to occur) (BLM 2007a, p. J-37). This designation, where it is 
applied, can offer some conservation consideration.
Evaluation of Information Provided in the Petition and in Our Files
    The petition does not provide specific information to support the 
assertion that existing regulatory mechanisms are inadequate to protect 
the subspecies from potential threats because it does not provide 
substantial information to support their assertion that threats are 
occurring under the other factors. The petition does not associate 
inadequate existing regulatory mechanisms to losses of Mono Basin 
skipper populations or declining population trends. We do not have 
information in our files related to the inadequacy of existing 
regulatory mechanisms for this subspecies. Also see the ``Summary of 
Common Threats'' section for information pertaining to the inadequacy 
of regulatory mechanisms as a potential threat.
    Based on our evaluation of the information provided in the petition 
and in our files, we have determined that the petition does not present 
substantial information to indicate that listing the Mono Basin skipper 
may be warranted due to the inadequacy of existing regulatory 
mechanisms.

    Factor E:
Information Provided in the Petition
    The petition asserts that the Mono Basin skipper may be vulnerable 
due to limited range and small population numbers (WildEarth Guardians 
2010, pp. 10-11, 40).
Evaluation of Information in the Petition and Our Files
    The petition does not present, nor do we have information in our 
files related to, population numbers, size, or trends for the Mono 
Basin skipper. The petition does not provide information on chance 
events or other threats to the subspecies and connect them to a 
possibly restricted range for this subspecies or the potential for such 
threats to occur in occupied habitats in the future. In the absence of 
specific information identifying such threats to the subspecies and 
connecting them to a restricted geographic range or small population 
numbers of the subspecies, or the potential for such events to occur in 
occupied habitats, we do not consider restricted geographic range or 
small population numbers by themselves to be threats to this 
subspecies. In addition, this subspecies, as indicated above, is 
distributed over more than one population thereby reducing its 
extinction vulnerability due to stochastic (random) events. Also see 
the ``Summary of Common Threats'' section for information pertaining to 
limited distribution and small population size as potential threats.
    Therefore, based on our evaluation of the information provided in 
the petition and in our files, we have determined that the petition 
does not present substantial information to indicate that listing the 
Mono Basin skipper may be warranted due to other natural or manmade 
factors affecting the subspecies' continued existence.
Railroad Valley Skipper (Hesperia uncas fulvapalla)
    Because two of the petitioned subspecies share the same common 
name, Railroad Valley skipper, we also include their scientific name 
throughout the analyses for clarity.
    We accept the characterization of the Railroad Valley skipper 
(Hesperia uncas fulvapalla) as a valid subspecies based on its 
description by Austin and McGuire (1998, p. 777). A single brood flies 
from mid June to mid July (Austin and McGuire 1998, p. 777). Adults 
have been documented nectaring on thistles (Cirsium sp.) (Austin and 
McGuire 1998, p. 777).
    The Railroad Valley skipper's (H. u. fulvapalla) type locality is 
Lockes Ponds, a grassy alkaline meadow near Lockes in Railroad Valley, 
Nye County, Nevada (Austin and McGuire 1998, p. 777). The Nevada 
Natural Heritage Program (NNHP) (2006, p. 38; NNHPD 2008) indicates the 
subspecies has been documented near three spring sites (Currant, 
Duckwater, and Lockes) in Railroad Valley, Nye County. Austin and 
McGuire (1998, p. 777) indicate this subspecies is also known from 
other alkaline meadows in Railroad Valley and the Calleo area, Juab 
County, Utah. However, according to the petition, subsequent literature 
does not report this subspecies from Utah (WildEarth Guardians 2010, p. 
29).

    Factor A:
Information Provided in the Petition
    The petition asserts that water development, agriculture, livestock 
grazing, energy production, and climate change may impact this 
subspecies (WildEarth Guardians 2010, pp. 30-31, 40). The petition 
provides information indicating that both Duckwater and Lockes Springs 
are considered ``highest conservation priority'' areas, while Currant 
Springs is considered a companion site (NNHP 2006, pp. 10-11). The NNHP 
includes Railroad Valley springs and marshes in general as one of the 
State's 26 highest priority wetland areas (NHHP 2007, p. 8), and they 
are considered 80 percent degraded and 20 percent converted to other 
uses (NNHP 2007, p. 41). Moderate to high stressors--activities, 
events, or other stimuli that cause stress to a species or 
environment--impacting these general wetland areas in Railroad Valley 
include water diversion and development, groundwater pumping, 
hydrogeomorphic modification, agriculture, livestock grazing, 
recreation, nonnative species invasion, and energy development (NNHP 
2007, p. 41). The petition implies that these stressors impacting the 
general wetland areas are negatively impacting the Railroad Valley 
skipper (H. u. fulvapalla).
    The petition claims that SNWA's proposal to pump groundwater in 
central Nevada is likely to affect spring discharges in Railroad 
Valley, including discharges for Duckwater and Lockes Springs (Deacon 
et al. 2007, p. 693). Current pumping plus water rights sought for 
future pumping represent 265 percent of the estimated groundwater 
perennial yield for Railroad Valley (Deacon et al. 2007, p. 691). The 
petition references information related to groundwater pumping 
simulations for SNWA's proposed project, and pumping could lower water 
levels in northern and southern Railroad Valley (Schaeffer and Harrill 
1995, p. 29). The simulated drawdowns for Duckwater, occurring in the 
central part of northern Railroad Valley, are a few tenths of a foot in 
upper and lower cell layers (Schaeffer and Harrill 1995, p. 29) and are 
not demonstrated until simulated pumping occurs during phase four, 
decades later (Schaeffer and Harrill 1995, pp. 31-32). The simulated 
drawdowns in the southern part of Railroad Valley are more substantial, 
reaching about 100 ft (30.5 m) in upper and lower cell layers 
(Schaeffer and Harrill 1995, p. 29). Because pumping wells are to be 
placed primarily in the southern part of Railroad Valley, pumping will 
have a

[[Page 61545]]

greater impact in the south than in the north (Schaeffer and Harrill 
1995, p. 29).
    In addition, most of Nevada's oil production comes from several 
small oil fields in Railroad Valley (WildEarth Guardians 2010, p. 30), 
and this type of development may also affect spring aquifers in 
Railroad Valley (Deacon Williams and Williams 1989, p. 466).
Evaluation of Information Provided in the Petition and in Our Files
    Although we have one letter from a contractor indicating that 
lowering the water table and overgrazing could theoretically threaten 
the subspecies (Austin et al. 2000, p. 3), our evaluation of all 
available information indicates that these threats are unlikely to 
impact the subspecies. Based on information in our files, the Railroad 
Valley skipper (H. u. fulapalla) occurs in the Railroad Valley Northern 
hydrographic area (173B) (NDWR 2010). The perennial yield of 
the Railroad Valley Northern hydrographic area is 75,000 afy 
(92,510,000 m\3\/year), and there are 24,943 afy (30,770,000 m\3\/year) 
committed; thus, the permitted groundwater rights do not approach or 
exceed the estimated average annual recharge in this hydrographic area.
    Furthermore, Service files provide information about native habitat 
restoration efforts conducted at both Duckwater Springs and Lockes 
Springs. In 2006 and 2008, restoration efforts were conducted at Big 
Warm Spring and Little Warm Spring on the Duckwater Indian Reservation 
to reduce impacts from water diversion (Poore 2008a, pp. 1-4). Big Warm 
Spring and Little Warm Spring are offered some protections through 
long-term Partners for Fish and Wildlife Program grant agreements, 
funding through section 6 of the Act, and a Safe Harbor Agreement (Fish 
and Wildlife Service and Duckwater Shoshone Tribe 2007, pp. 1-25; Fish 
and Wildlife Service 2009, pp. 1-36). These agreements should prevent 
future threats from spring development, water pollution, recreation, 
and overgrazing. In 2005, Lockes Ranch (where the Lockes Springs occur) 
was purchased by the State of Nevada through a Recovery Lands 
Acquisition grant for protection of the Railroad Valley springfish 
(Crenichthys nevadae), a federally listed threatened fish with 
designated critical habitat. While there is no formal protection for 
butterflies in the State of Nevada, this purchase and associated 
conservation measures for the springfish provides some protection to 
riparian habitat, spring systems, and associated wildlife. The State 
actively manages recreation and grazing or has eliminated these 
activities from portions of Lockes Ranch such that potential past 
threats to the subspecies have been reduced. In 2008, the four springs 
(Big, North, Hay Corral, and Reynolds) on Lockes Ranch underwent 
restoration, including re-creation of a sinuous channel, improvements 
to other existing channels, elimination of an irrigation ditch, and 
removal of nonnative vegetation from the spring systems (Poore 2008b, 
pp. 1-10). The land acquisition and the restoration activities have 
reduced impacts from livestock grazing and recreation, and eliminated 
impacts from spring diversion at these sites. While these restoration 
activities at both Duckwater and Lockes Ranch are directed at improving 
habitat conditions for the Railroad Valley springfish, they may also 
have provided habitat benefits to the Railroad Valley skipper (H. u. 
fulvapalla) (if it occurs in the immediate vicinity); this suggests 
that potential threats to the skipper from water diversions, livestock 
grazing, and invasive species have been significantly reduced for the 
long-term.
    The information presented in the petition for this subspecies does 
not provide supporting information that groundwater development has or 
may affect habitat for the Railroad Valley skipper (H. u. fulvapalla). 
Information in our files demonstrates that the assertion that water 
development may impact the butterfly is likely unfounded, because the 
subspecies occurs in northern Railroad Valley where groundwater does 
not appear to be overcommitted. Information in our files indicates that 
SNWA's proposed project may result in only minor, if any, water table 
lowering in the area that the subspecies occurs, and that recent 
conservation efforts have significantly reduced threats.
    The petition does not provide specific supporting information that 
the Railroad Valley skipper (H. u. fulvapalla) may be impacted by 
agriculture, livestock grazing, energy production, or climate change at 
occupied locations. The petition does not provide specific supporting 
information regarding past, present, or future conditions of these 
threats or their scope, immediacy, or intensity at occupied or suitable 
habitat. The petition does not report loss of populations or reduction 
in numbers of this subspecies to these potential threats, which could 
suggest a negative response to a threat such as those claimed. We do 
not have in our files specific information to support the concern of 
potential threats from agriculture, grazing, energy development, or 
climate change to impacts to Railroad Valley skipper (H. u. fulvapalla) 
populations or its habitat. Also see the ``Summary of Common Threats'' 
section for information pertaining to water development, agriculture, 
livestock grazing, and climate change as potential threats.
    Based on our evaluation of the information provided in the petition 
and in our files, we have determined that the petition does not present 
substantial information to indicate that listing the Railroad Valley 
skipper (H. u. fulvapalla) may be warranted due to the present or 
threatened destruction, modification, or curtailment of its habitat or 
range.

    Factors B and C:
Information Provided in the Petition
    The petition states that it is not known whether overutilization, 
disease, or predation are threats to this subspecies (WildEarth 
Guardians 2010, p. 8). Information referenced in the petition indicates 
that 105 males and 75 females were collected between 1984 and 1990 
(Austin and McGuire 1998, p. 777).
Evaluation of Information Provided in the Petition and in Our Files
    The petition does not provide information that overutilization, 
disease, or predation has negatively impacted this subspecies. While 
the petition's referenced material provides some information about 
known numbers of collections, the petition does not provide any 
information about the population sizes or trends during this time 
period. Given the low number of individuals collected over a 6-year 
time span, the length of time since these collections were made, and 
the lack of information about the relative impact to the population, 
the petition does not provide substantial information to indicate that 
collection may be a threat to the subspecies. We have no information in 
our files related to overutilization, disease, or predation for this 
subspecies. Also see the ``Summary of Common Threats'' section for 
information pertaining to overutilization, disease, and predation as 
potential threats.
    Based on our evaluation of the information provided in the petition 
and in our files, we have determined that the petition does not present 
substantial information to indicate that listing the Railroad Valley 
skipper (H. u. fulvapalla) may be warranted due to Factor B 
(overutilization for commercial, recreational, scientific, or 
educational purposes) or Factor C (disease or predation).

    Factor D:

[[Page 61546]]

Information Provided in the Petition
    The petition asserts that inadequate existing regulatory mechanisms 
are a threat to this subspecies (WildEarth Guardians 2010, p. 40). The 
BLM lists the Railroad Valley skipper (H. u. fulvapalla) as a sensitive 
species (BLM 2007a, p. J-37). This designation can offer it some 
conservation consideration.
Evaluation of Information Provided in the Petition and in Our Files
    The petition does not provide information to support the assertion 
that existing regulatory mechanisms are inadequate to protect the 
subspecies from potential threats because it does not provide 
substantial information to support their assertion that threats are 
occurring under the other factors. The petition does not associate 
inadequate existing regulatory mechanisms to losses of Railroad Valley 
skipper (H. u. fulvapalla) populations or declining population trends. 
We do not have information in our files related to the inadequacy of 
existing regulatory mechanisms for this subspecies. Also see the 
``Summary of Common Threats'' section for information pertaining to the 
inadequacy of existing regulatory mechanisms as a potential threat.
    Based on our evaluation of the information provided in the petition 
and in our files, we have determined that the petition does not present 
substantial information to indicate that listing the Railroad Valley 
skipper (H. u. fulvapalla) may be warranted due to the inadequacy of 
existing regulatory mechanisms.

    Factor E:
Information Provided in the Petition
    The petition indicates the subspecies may be vulnerable due to 
small population numbers (WildEarth Guardians 2010, pp. 10-11, 40). 
Austin (1985, pp. 125-126) indicates Hesperia uncas spp. appear to be 
restricted to the valleys where they occur. The petition suggests that 
isolated populations of the Railroad Valley skipper (H. u. fulvapalla) 
are probably unable to disperse to suitable habitat or interconnect 
with other populations especially where habitat fragmentation has 
occurred due to various factors such as land use, water development, 
and climate change (WildEarth Guardians 2010, p. 30).
Evaluation of Information Provided in the Petition and in Our Files
    The petition does not present, nor do we have specific information 
in our files, related to population sizes, numbers, or trends for the 
Railroad Valley skipper (H. u. fulvapalla). The petition does not 
provide information on chance events or other threats to the subspecies 
and connect them to potential small population size or restricted range 
or the potential for such chance events to occur in occupied habitats 
in the future. In the absence of specific information identifying such 
threats to the subspecies and connecting them to small populations or 
restricted range of the subspecies, or the potential for such events to 
occur in occupied habitats, we do not consider small population numbers 
or restricted range by themselves to be threats to this subspecies. In 
addition, this subspecies is distributed over more than one population 
thereby reducing its extinction vulnerability due to stochastic events. 
Also see the ``Summary of Common Threats'' section for information 
pertaining to limited distribution and small population size as 
potential threats.
    Therefore, based on our evaluation of the information provided in 
the petition and in our files, we have determined that the petition 
does not present substantial information to indicate that listing the 
Railroad Valley skipper (H. u. fulvapalla) may be warranted due to 
other natural or manmade factors affecting the subspecies' continued 
existence.
Railroad Valley Skipper (Hesperia uncas reeseorum)
    Because two of the subspecies share the same common name, Railroad 
Valley skipper, we also include their scientific name throughout the 
analyses for clarity.
    We accept the characterization of the Railroad Valley skipper 
(Hesperia uncas reeseorum) as a valid subspecies based on its 
description by Austin and McGuire (1998, p. 776). This subspecies flies 
as a single brood during mid June to early August (Austin and McGuire 
1998, p. 776). Adults have been documented using thistle (Cirsium spp.) 
for nectar (Austin and McGuire 1998, p. 776). The larval host plant is 
Sporobolus airoides (alkali sacaton) (Austin and Leary 2008, p. 11).
    The Railroad Valley skipper (H. u. reeseorum) is known from the 
Reese River and Mason Valleys in central (Lander County) and western 
Nevada (Lyon County), respectively, where it occurs in alkaline, 
Distichlis spicata (saltgrass) flats (Austin and McGuire 1998, p. 776). 
The type locality is located along Nevada State Route 722 (previously 
State Route 2) approximately 4 mi (6.4 km) east-northeast of the Reese 
River in an extensive alkaline flat in the river's floodplain (Austin 
and McGuire 1998, p. 776).

    Factor A:
Information Provided in the Petition
    The petition asserts that water development, agriculture, livestock 
grazing, and climate change may impact this subspecies (WildEarth 
Guardians 2010, pp. 33-34, 40). The petition provides information 
indicating that the NNHP ranks the Mason Valley/Walker River riparian 
zone among the 26 highest priority wetlands in Nevada (NNHP 2007, p. 
25). In this category, 100 percent of the wetland areas have been 
converted to other land uses or degraded (NNHP 2007, p. 38). Moderate 
to high stressors impacting wetlands in the Mason Valley/Walker River 
riparian zone include water diversion/development, groundwater pumping, 
hydrogeomorphic modifications, land development, agriculture, livestock 
grazing, mining, and nonnative species invasion (NNHP 2007, p. 38). In 
the lower Reese River Valley, 80 percent of the ``priority wetland 
areas'' have been converted to other land uses or degraded (NNHP 2007, 
p. 41). Moderate to high stressors impacting the wetlands in the lower 
Reese River Valley include water diversion/development, groundwater 
pumping, land development, agriculture, livestock grazing, and 
nonnative species invasion (NNHP 2007, p. 41). The petition implies 
that these activities which occur generally in wetland areas in Mason 
Valley/Walker River and lower Reese River Valley are impacting the 
Railroad Valley skipper (H. u. reeseorum).
Evaluation of Information Provided in the Petition and Our Files
    The petition does not provide, nor do we have in our files, 
specific locations where this subspecies has been observed other than 
the type locality. The petition does not provide specific, supporting 
information to indicate that the Railroad Valley skipper (H. u. 
reeseorum) may be impacted by water development, agriculture, livestock 
grazing, or climate change. The petition does not provide supporting 
information regarding past, present, or future condition of these 
threats or their scope, immediacy, or intensity at occupied or suitable 
habitat. The petition does not report loss of populations or reduction 
in numbers of this subspecies which could suggest a negative response 
to threats such as those claimed. We do not have information in our 
files related to potential threats from water development, agriculture, 
livestock

[[Page 61547]]

grazing, or climate change to Railroad Valley skipper (H. u. reeseorum) 
populations or its habitat. Also see the ``Summary of Common Threats'' 
section for information pertaining to water development, agriculture, 
livestock grazing, and climate change as potential threats.
    Based on our evaluation of the information provided in the petition 
and our files, we have determined that the petition does not present 
substantial information to indicate that listing the Railroad Valley 
skipper (H. u. reeseorum) may be warranted due to the present or 
threatened destruction, modification, or curtailment of its habitat or 
range.

    Factors B and C:
Information Provided in the Petition
    The petition states that it is not known whether overutilization, 
disease, or predation are threats to this subspecies (WildEarth 
Guardians 2010, p. 8). Based on information referenced in the petition, 
138 male and 82 female specimens were collected between 1969 and 1984 
(Austin and McGuire 1998, p. 776).
Evaluation of Information Provided in the Petition and Our Files
    The petition does not provide information that overutilization, 
disease, or predation has negatively impacted the subspecies. While the 
petition's referenced material provides some information about known 
numbers of collections, the petition does not provide any information 
about the population sizes or trends during this time period. Given the 
low number of individuals collected over a 15-year time span, the 
length of time since these collections were made, and the lack of 
information about the relative impact to the population, the petition 
does not provide substantial information to indicate that collection 
may be a threat to the subspecies. We have no information in our files 
related to overutilization, disease, or predation for this subspecies. 
Also see the ``Summary of Common Threats'' section for information 
pertaining to overutilization, disease, and predation as potential 
threats.
    Based on our evaluation of the information provided in the petition 
and our files, we have determined that the petition does not present 
substantial information to indicate that listing the Railroad Valley 
skipper (H. u. reeseorum) may be warranted due to Factor B 
(overutilization for commercial, recreational, scientific, or 
educational purposes) or Factor C (disease or predation).

    Factor D:
Information Provided in the Petition
    The petition asserts that inadequate existing regulatory mechanisms 
are a threat to this subspecies (WildEarth Guardians 2010, pp. 8, 40). 
The BLM does not list this subspecies as a sensitive species (BLM 
2007a).
Evaluation of Information Provided in the Petition and in Our Files
    The petition does not provide information to support the assertion 
that existing regulatory mechanisms are inadequate to protect the 
subspecies from potential threats because it does not provide 
substantial information to support their assertion that threats are 
occurring under the other factors. The petition does not associate 
inadequate existing regulatory mechanisms to losses of Railroad Valley 
skipper (H. u. reeseorum) populations or declining population trends. 
We do not have information in our files related to the inadequacy of 
existing regulatory mechanisms for this subspecies. Also see the 
``Summary of Common Threats'' section for information pertaining to the 
inadequacy of existing regulatory mechanisms as a potential threat.
    Based on our evaluation of the information provided in the petition 
and our files, we have determined that the petition does not present 
substantial information to indicate that listing the Railroad Valley 
skipper (H. u. reeseorum) may be warranted due to the inadequacy of 
existing regulatory mechanisms.

    Factor E:
Information Provided in the Petition
    The petition indicates that this subspecies may be vulnerable due 
to small population numbers (WildEarth Guardians 2010, pp. 10-11, 40). 
Austin (1985, pp. 125-126) indicates Hesperia uncas spp. appear to be 
restricted to the valleys where they occur. The petition suggests that 
isolated populations of this subspecies of the Railroad Valley skipper 
(H. u. reeseorum) are probably unable to disperse to suitable habitat 
or interconnect with other populations especially where land use, water 
development, or climate change fragment habitat (WildEarth Guardians 
2010, pp. 33).
Evaluation of Information Provided in the Petition and in Our Files
    The petition does not present, nor do we have specific information 
in our files related to population numbers, size, or trends for the 
Railroad Valley skipper (H. u. reeseorum). The petition did not provide 
information on chance events or other threats to the subspecies and 
connect them to small population numbers or restricted range or the 
potential for such chance events to occur in occupied habitats in the 
future. In the absence of specific information identifying such threats 
to the subspecies and connecting them to small population numbers or 
restricted range of the subspecies, or the potential for such events to 
occur in occupied habitats, we do not consider small population numbers 
or restricted range by themselves to be threats to this subspecies. In 
addition, this subspecies is distributed over more than one population, 
thereby reducing its extinction vulnerability due to stochastic events. 
Also see the ``Summary of Common Threats'' section for information 
pertaining to limited distribution and small population size as 
potential threats.
    Therefore, based on our evaluation of the information provided in 
the petition and our files, we have determined that the petition does 
not present substantial information to indicate that listing the 
Railroad Valley skipper (H. u. reeseorum) may be warranted due to other 
natural or manmade factors affecting the subspecies' continued 
existence.
Species for Which Substantial Information Was Presented
    In this section, the butterfly subspecies are listed in 
alphabetical order by their common names.
Baking Powder Flat Blue Butterfly (Euphilotes bernardino minuta)
    We accept the characterization of the Baking Powder Flat blue 
butterfly as a valid subspecies based on its description by Austin 
(1998b, p. 549). The Baking Powder Flat blue butterfly is exclusively 
associated with Eriogonum shockleyi (Shockley's buckwheat), 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; 1998a, p. 550), and there is one brood (Austin 
1993, p. 6).
    The Baking Powder Flat blue butterfly is only known from Baking 
Powder Flat in Spring Valley, in Lincoln and White Pine Counties, 
Nevada, a flat valley bottom with scattered sand dunes (Austin 1998b, 
p. 550; Austin and Leary 2008, pp. 68-69). Baking Powder Flat contains 
the largest known contiguous

[[Page 61548]]

habitat for the Baking Powder Flat blue butterfly (BLM 2009, p. 20). In 
1993, Austin (1993, p. 5) reported two colonies in southern Spring 
Valley, and also suggested that other areas could support the host 
plant (Austin 1993, p. 6). Eriogonum shockleyi grows on relatively hard 
and bare areas between the sand dunes (Austin 1998b, p. 550). Searches 
of nearby areas in southern Spring Valley did not reveal additional 
colonies of the subspecies or its host plant (Austin 1993, p. 5; 1998b, 
p. 550); however, Austin and Leary (2008, pp. 68-69) list what appear 
to be seven discrete locations where this subspecies (adults and 
larvae) has been seen between 1969 and 2002. The NNHPD (2008) indicates 
that this subspecies occurs in the Baking Powder Flat area near Blind 
Spring. 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).

    Factor A:
Information Provided in the Petition
    The petition asserts that water development, fire, nonnative plant 
invasion, livestock grazing, and climate change may impact this 
subspecies (WildEarth Guardians 2010, pp. 13-14, 40). The petition 
indicates that the NNHP has ranked the Baking Powder Flat playa/
ephemeral pool/spring pool complex among the 26 highest priority 
wetland areas in the State (NNHP 2007, p. 8). The moderate- to-high 
stressors impacting the complex include water diversion and 
development, groundwater pumping, livestock grazing, agriculture, 
mining, and nonnative species invasion (NNHP 2007, p. 42). It is 
estimated that about 30 percent of the wetland area has been degraded 
or converted to other land uses (NHHP 2007, p. 42). The petition 
implies that these stressors impacting the wetland complex are 
negatively impacting the Baking Powder Flat blue butterfly.
    The petition raises concerns about SNWA's proposal to pump and 
transfer approximately 91,200 afy (112,500,000 m\3\/year) of 
groundwater from Spring Valley (Meyers 2006, p. 6) to Las Vegas, 
Nevada. This proposed project could lower the water table in Spring 
Valley by 200 ft (61 m) in 100 years, and 300 ft (91 m) in 1,000 years 
(Meyers 2006, p. 75), and Charlet (2006, p. 19) predicted that 
desertification of Baking Powder Flat would result. The SNWA's proposed 
project may directly impact the Baking Powder Flat area, including the 
Baking Powder Flat Area of Critical Environmental Concern (ACEC), due 
to monitoring and facility installation and construction activities 
(BLM 2009, pp. 20-21). The ACEC was established in 2008 (72 FR 67748, 
p. 67749; 73 FR 55867) to protect the Baking Powder Flat blue butterfly 
(BLM 2009, p. 20).
    According to the petition, additional threats to this subspecies 
and its habitat include fire in the surrounding sagebrush habitat and 
subsequent nonnative plant species invasion (B. Boyd, pers. comm. cited 
by WildEarth 2010, p. 14) and climate change. The petition also 
mentions disturbance to this subspecies' host plant from trampling, and 
soil compaction from livestock grazing (B. Boyd, pers. comm. cited in 
WildEarth 2010, p. 13, NatureServe 2009b, p. 2). According to the 
petition, three grazing allotments appear to overlap with the Baking 
Powder Flat ACEC (BLM 2007b, Map 2.4 16-1). Areas of the ACEC can be 
``heavily impacted'' by livestock grazing (BLM 2009, p. 21). In 
addition to livestock grazing, plant collecting and limited off-road 
vehicle use are also authorized within the ACEC (BLM 2007b, p. 2.4-
101).
Evaluation of Information Provided in the Petition and Our Files
    While several activities as listed above (water diversion and 
development, groundwater pumping, livestock grazing, agriculture, 
mining, and nonnative species invasion) may be impacting a portion (30 
percent) of the Baking Powder Flat wetland complex, the petition does 
not provide supporting information that these activities are occurring 
in occupied Baking Powder Flat blue butterfly habitat and are 
negatively impacting it, especially since the subspecies' host plant 
does not occur in wetland areas. Adults and larvae utilize Eriogonum 
shockleyi to meet life-history requirements. This plant grows on 
relatively hard and bare areas between the sand dunes in Baking Powder 
Flat (Austin 1998b, p. 550) and mostly on gravelly, clayey, or sandy 
soils, or on rocky outcrops and ledges, in association with Sarcobatus 
(greasewood), Atriplex (shadscale), and Artemisia (sagebrush) (Kartesz 
1987, p. 282). It has been described by BLM as common in Baking Powder 
Flat (BLM 2009, p. 20). We have information in our files that indicates 
the permitted groundwater rights in the Spring Valley hydrographic area 
(184) exceed the estimated average annual recharge; the 
perennial yield of the Spring Valley hydrographic area is 80,000 afy 
(98,680,000 m\3\/year), and there are 86,085 afy (106,200,000 m\3\/
year) committed (NDWR 2010). However, because the host plant grows in 
dry areas and not within the Baking Powder Flat wetland complex, it is 
unlikely that current overcommitted groundwater rights or SNWA's 
proposed water development project are or will indirectly impact the 
host plant, and thus the Baking Powder Flat blue butterfly, through 
possible lowering of the water table.
    We have information in our files (Austin et al. 2000, p. 3; Austin 
1993, p. 7) that indicates that soil compaction or direct destruction 
of host plants from activities such as livestock trampling and vehicles 
may impact the Baking Powder Flat blue butterfly, though no further 
specific, supporting information is provided.
    For the other threats mentioned (fire and climate change), the 
petition and information in our files do not present specific 
supporting information regarding past, present, or future conditions of 
these potential threats or their scope, immediacy, or intensity at 
occupied or suitable habitats. The petition does not report loss of 
populations or reduction in numbers of this subspecies which could 
suggest a negative response to these threats. Also see ``Summary of 
Common Threats'' section for information pertaining to water 
development, livestock grazing, and climate change as potential 
threats.
    Based on our evaluation of the information provided in the petition 
and in our files, we have determined that the petition does not present 
substantial information to indicate that listing the Baking Powder Flat 
blue butterfly may be warranted due to the present or threatened 
destruction, modification, or curtailment of its habitat or range from 
water development, fire, nonnative species invasion, or climate change.
    However, due to potential adverse impacts from livestock grazing 
and disturbance to the host plant from trampling and soil compaction 
from livestock grazing and vehicles, we have determined that 
information in the petition and our files does present substantial 
information to indicate that the Baking Powder Flat blue butterfly may 
warrant listing due to the present or threatened destruction, 
modification, or curtailment of its habitat or range from livestock 
grazing and vehicle use. Injury to or loss of the host plant, Eriogonum 
shockleyi, populations would negatively impact larvae and adults as 
both life stages utilize this plant for food and shelter. During our 
status review for this subspecies, we

[[Page 61549]]

will further investigate these potential threats.

    Factors B and C:
Information Provided in the Petition
    The petition states that it is not known whether overutilization, 
disease, or predation are threats to this subspecies (WildEarth 
Guardians 2010, p. 8). According to Austin (1998b, p. 550) as 
referenced in the petition, 61 males and 41 females of this subspecies 
were collected between 1978 and 1980.
Evaluation of Information Provided in the Petition and Our Files
    The petition does not provide information that overutilization, 
disease, or predation has negatively impacted the subspecies. While the 
petition's referenced material provides some information about known 
numbers of collections, the petition does not provide any information 
about the population sizes or trends during this time period. Given the 
relatively low number of individuals collected over a 2-year period, 
the length of time since the collections were made, and the lack of 
information about the relative impact to the population, the petition 
does not provide substantial information to indicate that collection 
may be a threat to this subspecies. We have no information in our files 
related to overutilization, disease, or predation for this subspecies. 
Also see ``Summary of Common Threats'' section for information 
pertaining to overutilization, disease, and predation as potential 
threats.
    Based on our evaluation of the information provided in the petition 
and our files, we have determined that the petition does not present 
substantial information to indicate that listing the Baking Powder Flat 
blue butterfly may be warranted due to Factor B (overutilization for 
commercial, recreational, scientific, or educational purposes) or 
Factor C (disease or predation). However, during our status review for 
this subspecies, we will further investigate these potential threats.

    Factor D:
Information Provided in the Petition
    The petition asserts that inadequate existing regulatory mechanisms 
are a threat to this subspecies (WildEarth Guardians 2010, pp. 8, 40). 
The petition states that this subspecies is a BLM sensitive species 
(BLM 2007a, p. J6), which can afford it some conservation 
consideration. In addition, BLM has designated a portion of the Baking 
Powder Flat area as an ACEC (72 FR 67748, p. 67749; 73 FR 55867 
entire). Livestock grazing, plant collecting, and limited off-road 
vehicle use are authorized within the Baking Powder Flat ACEC (BLM 
2007b, p. 2.4-101). According to BLM (2009, 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.''
Evaluation of Information Provided in the Petition and Our Files
    According to information in our files, the Baking Powder Flat ACEC 
does not appear to cover the entire area where Baking Powder Flat blue 
butterflies have been known to occur (BLM 2008b, p. C-14). Also see the 
``Summary of Common Threats'' section for information pertaining to the 
inadequacy of existing regulatory mechanisms as a potential threat.
    We have determined that livestock grazing and vehicle use may be 
threats to the Baking Powder Flat blue butterfly, as discussed in 
Factor A. Thus, we have determined that the information in the petition 
and our files presents substantial information indicating that existing 
regulatory mechanisms may be inadequate as they relate to livestock 
grazing and vehicle use, in general on BLM lands, and also in relation 
to the ACEC. During our status review for this subspecies, we will 
further investigate these and other potential threats and whether 
existing regulatory mechanisms may be inadequate.

    Factor E:
Information Provided in the Petition
    The petition indicates that the Baking Powder Flat Blue butterfly 
may be vulnerable due to limited range and small population numbers 
(WildEarth Guardians 2010, pp. 10-11, 40).
Evaluation of Information in the Petition and Our Files
    The petition does not present, nor do we have in our files, 
information related to population numbers, size, or trends for the 
Baking Powder Flat blue butterfly. The petition does not provide 
information on chance events or other threats to the subspecies and 
connect them to a restricted range or small population number or the 
potential for such threats to occur in occupied habitats in the future. 
Since this subspecies is distributed over more than one population, its 
extinction vulnerability due to stochastic events may be reduced. In 
the absence of this information and connection, we do not consider 
restricted geographic range or small population numbers by themselves 
to be threats to this subspecies. Also see the ``Summary of Common 
Threats'' section for information pertaining to limited distribution 
and small population size as potential threats.
    Therefore, based on the information provided in the petition and 
our files, we have determined that the petition does not present 
substantial information to indicate that listing the Baking Powder Flat 
blue butterfly may be warranted due to other natural or manmade factors 
affecting the subspecies' continued existence. However, during our 
status review of this subspecies, we will further investigate whether 
biological vulnerability is a threat to this subspecies.
Bleached sandhill skipper (Polites sabuleti sinemaculata)
    We accept the characterization of the bleached sandhill skipper as 
a valid subspecies based on its description by Austin (1987, pp. 7-8). 
Distichlis spicata may serve as the larval host plant (Austin 1987, p. 
8). Adults have been seen nectaring on white and yellow composites 
(Asteraceae) (Austin 1987, p. 8). 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. 2000, p. 4).
    The bleached sandhill skipper is known from one location (Baltazor 
Hot Spring) near Denio Junction, Humboldt County, Nevada (Austin 1987, 
p. 8; Austin et al. 2000, p. 4; NNHPD 2008; B. Boyd, pers. comm. cited 
in WildEarth Guardians 2010, p. 15). The area is a salt flat near a hot 
spring and is densely covered with Distichlis spicata (Austin 1987, p. 
8). 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 to 3 years ago (B. Boyd, 
pers. comm. cited in WildEarth Guardians 2010, p. 15). We have no 
information in the petition or our files about this subspecies 
population dynamics to

[[Page 61550]]

know if this level of population decline is unusual.

    Factor A:
Information Provided in the Petition
    The petition provides information indicating that the Baltazor 
Meadow-Continental Lake wetland area has been identified as a priority 
wetland in Nevada, and where 20 percent of this wetland area has been 
degraded or converted to other land uses (NHHP 2007, p. 36). The 
moderate-to-high stressors in this area include water diversion/
development, groundwater pumping, livestock grazing, and energy 
development (NHHP 2007, p. 36). The petition implies these activities 
are adversely impacting the bleached sandhill skipper.
Evaluation of Information Provided in the Petition and Our Files
    The petition suggests that threats (water development, livestock 
grazing, and energy development) to the Baltazor Meadow-Continental 
Lake wetland area could impact the bleached sandhill skipper; however, 
no additional information is provided. The petition does not provide 
specific supporting information regarding past, present, or future 
conditions of these threats or their scope, immediacy, or intensity at 
occupied or suitable habitat. The petition does not indicate the 
acreage of this occupied location. We do not we have information in our 
files indicating whether this location is large or small. The petition 
does indicate a recent reduction in numbers of the bleached sandhill 
skipper, which could suggest a negative response to these threats, but 
details regarding this decline and the reason(s) for it are not 
provided. The petition does not present information related to 
population numbers, size, or trends for the bleached sandhill skipper. 
The petition does not elaborate on when the apparent population decline 
occurred, its magnitude, or reasons for it. It is unknown whether this 
decline 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). However, we are concerned with this potential decline 
in the only known population for this subspecies. Our files also 
include a statement that the bleached sandhill skipper could be 
impacted by water table changes (Austin et al. 2000, p. 4), but there 
is no specific supporting information related to this potential threat 
or resulting negative impacts to this subspecies. The SNWA's proposed 
water development project is not expected to impact groundwater in 
Humboldt County, located in northwest Nevada, where this species 
occurs. Also see the ``Summary of Common Threats'' section for 
information pertaining to water development and livestock grazing as 
potential threats.
    Based on our evaluation of the information provided in the petition 
and in our files, we have determined that the petition does present 
substantial information to indicate that listing the bleached sandhill 
skipper may be warranted due to the present or threatened destruction, 
modification, or curtailment of its habitat or range resulting from 
water development (other than SNWA's proposed project) due to a 
reported possible decline in numbers of the bleached sandhill skipper 
known from a single location. During our status review for this 
subspecies, we will further investigate this and other potential 
threats.

    Factors B and C:
Information Provided in the Petition
    The petition states that it is not known whether overutilization, 
disease, or predation are threats to this subspecies (WildEarth 
Guardians 2010, p. 8). According to Austin (1987, p. 8), referenced in 
the petition, 27 males and 14 females were collected between 1984 and 
1985.
Evaluation of Information Provided in the Petition and Our Files
    The petition does not provide information that overutilization, 
disease, or predation has negatively impacted the subspecies. While the 
petition's referenced material provides some information about known 
numbers of collections, the petition does not provide any information 
about the population sizes or trends during this time period. Given the 
low number of individuals collected, the length of time since the 
collections were made, and the lack of information about the relative 
impact to the population, the petition does not provide substantial 
information to indicate that collection may be a threat to the 
subspecies. We have no information in our files related to 
overutilization, disease, or predation for this subspecies. Also see 
the ``Summary of Common Threats'' section for information pertaining to 
overutilization, disease, and predation as potential threats.
    Based on our evaluation of the information provided in the 
petition, we have determined that the petition does not present 
substantial information to indicate that listing the bleached sandhill 
skipper may be warranted due to Factor B (overutilization for 
commercial, recreational, scientific, or educational purposes) or 
Factor C (disease or predation). However, during our status review for 
this subspecies, we will further investigate these potential threats.

    Factor D:
Information Provided in the Petition
    The petition asserts that existing regulatory mechanisms are 
inadequate (WildEarth Guardians 2010, pp. 8, 40). The petition states 
that the BLM lists the bleached sandhill skipper as a sensitive species 
in Nevada (BLM 2007a, p. J-37), a status that can offer it some 
conservation consideration.
Evaluation of Information Provided in the Petition and in Our Files
    The petition does not provide specific supporting information 
connecting the potential threats indicated under Factor A, or the 
extent of these threats, to adverse effects to the known population of 
the bleached sandhill skipper, except to indicate a recent reduction in 
the number of individuals of this subspecies, which could suggest a 
negative response to potential threats. The details of this decline and 
the cause(s) of it were not described. We do not have information 
available in our files related to the inadequacy of existing regulatory 
mechanisms for this subspecies. Also see the ``Summary of Common 
Threats'' section for information pertaining to the inadequacy of 
existing regulatory mechanisms as a potential threat.
    Based on our evaluation of the information provided in the petition 
suggesting that a reduction in the number of individuals of bleached 
sandhill skipper may have occurred at the single known population, 
possibly due to water development we have determined that the petition 
does present substantial information to indicate that listing the 
bleached sandhill skipper may be warranted due to the inadequacy of 
existing regulatory mechanisms. During our status review for this 
subspecies, we will further investigate these and other potential 
threats and whether existing regulatory mechanisms may be inadequate.

    Factor E:
Information Provided in the Petition
    The petition indicates that this subspecies is known from only one 
area; although thousands had been seen in the past, a decline appears 
to have occurred 2 to 3 years ago (A. Warren, pers. comm. and B. Boyd 
pers. comm., cited in WildEarth Guardians 2010, p. 15). Therefore, the 
petition asserts

[[Page 61551]]

this subspecies may be vulnerable due to limited distribution and small 
population numbers (WildEarth Guardians 2010, pp. 10-11, 40).
Evaluation of Information Provided in the Petition and in Our Files
    The petition does not present detailed information, nor do we have 
information in our files, related to population numbers, size, or 
trends for the bleached sandhill skipper. The petition does not 
elaborate on when the apparent population decline occurred, its 
magnitude, or reasons for it. The petition does not indicate the size 
of this site. A small area may be at higher risk of extinction than a 
large site. The petition does not provide information on chance events 
or other threats to the subspecies and connect them to a restricted 
range or small population size, or the potential for such chance events 
to occur in occupied habitats in the future. In the absence of this 
information and connection, we do not consider restricted geographic 
range or small population numbers by themselves to be threats to this 
subspecies. Also see the ``Summary of Common Threats'' section for 
information pertaining to limited distribution and small population 
size as potential threats. However, due to the single known occupied 
location and reported decline in numbers, any other potential threat to 
the subspecies in addition to the possible threat due to water 
development could exacerbate this situation.
    Therefore, based on the information provided in the petition and in 
our files, we have determined that the petition does present 
substantial information to indicate that listing the bleached sandhill 
skipper may be warranted due to other natural or manmade factors 
affecting the subspecies' continued existence due to the reported 
decline of its single known population. During our status review, we 
will further investigate this potential threat.
Steptoe Valley Crescentspot (Phyciodes cocyta arenacolor)
    We accept the characterization of the Steptoe Valley crescentspot 
as a valid subspecies based on its description by Austin (1998c, p. 
577) and recent updated nomenclature (NatureServe 2009d, p. 1; A. 
Warren, pers. comm. cited in WildEarth Guardians 2010, p. 34). Adults 
are known to fly as one brood (Austin 1993, p. 9) during early July to 
mid-August (Austin 1993, p. 9; Austin 1998c, p. 577). Aster ascendens 
(long-leaved aster) has been documented as a larval host plant (Austin 
and Leary 2008, p. 102).
    The Steptoe Valley crescentspot occurs at Warm Springs in Steptoe 
Valley, White Pine County, Nevada (Austin 1998c, p. 577; Austin and 
Leary 2008, p. 102). Austin (1993, pp. 8-9) found this subspecies in 
the moist flats adjacent to the Duck Creek drainage in Steptoe Valley 
from Warm Springs to northwest of McGill. Specific locations include 
along Duck Creek and near Bassett Lake (Austin 1993, p. 9; NNHPD 2008). 
Occurrences have been reported at Monte Neva Hot Springs and near 
McGill, White Pine County, Nevada (NNHP 2006, p. 42). The NNHP (2009, 
p. 7) database indicates three Nevada occurrences, but the locations 
are not identified.

    Factor A:
Information Provided in the Petition
    The petition asserts that water development and climate change may 
impact the Steptoe Valley crescentspot (WildEarth Guardians 2010, pp. 
36, 40). Information provided in the petition indicates that the NNHP 
considers Monte Neva Hot Springs of ``highest conservation priority'' 
(NNHP 2006, p. 11). The McGill site is considered a companion site 
associated with other higher priority conservation sites (NNHP 2006, p. 
11). In 2007, the NNHP included Steptoe Valley, with a number of 
wetland areas found within the Valley, in the list of the 26 highest 
priority wetlands in the State (NNHP 2007, p. 42). The moderate-to-high 
stressors impacting this valley's wetland areas include water 
diversion/development, groundwater pumping, agriculture, grazing, 
nonnative species invasion, and energy development (NNHP 2007, p. 42). 
The petition implies these activities may impact the Steptoe Valley 
crescentspot.
    Deacon (2009, p. 6), as referenced in the petition, states that 
SNWA's proposed groundwater development project could lower the water 
table by 700 ft (213.4 m) in several valleys, including Steptoe Valley, 
adversely impacting spring-fed habitats (WildEarth Guardians 2010, p. 
36).
Evaluation of Information Provided in the Petition and Our Files
    The petition does not provide specific supporting information to 
indicate that the Steptoe Valley crescentspot is impacted from 
livestock grazing, trampling and clearing of vegetation, agricultural 
pollution, or climate change. The petition does not provide specific 
supporting information regarding past, present, or future conditions of 
these threats, or their scope, immediacy, or intensity at occupied or 
suitable habitats. However, there is some information provided in the 
petition and in our files to suggest that water development may impact 
this subspecies due to overcommitment of groundwater in Steptoe Valley 
and this overcommitment's potential for adverse impacts to aquatic 
habitat. 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 reduction in larval or nectar plant 
abundance). Information in our files indicates that the Steptoe Valley 
hydrographic area (179) has been classified as a ``Designated 
Groundwater Basin'' by the NSE and that permitted groundwater rights 
exceed the estimated average annual recharge; the perennial yield of 
Steptoe Valley is 70,000 afy (86,340,000 m\3\/year); however, 
approximately 97,000 afy (119,600,000 m\3\/year) is committed for use 
(NDWR 2010). When groundwater extraction exceeds aquifer recharge, the 
result may be surface water-level decline, spring drying, and 
degradation or loss of aquatic habitat (Zektser et al. 2005, pp. 396-
397). Our files also include information indicating that habitat 
alterations, particularly water table changes and overgrazing (Austin 
et al. 2000, p. 2), may impact the Steptoe Valley crescentspot; 
however, this information is not specific. Austin (1993, pp. 9-10) 
indicates that potential threats to the subspecies appear to be habitat 
disturbance and destruction, such as overgrazing, trampling and 
clearing of vegetation, water diversion, and agricultural pollution; 
however, no specific supporting information is provided. We do not have 
specific supporting information in our files regarding the other 
potential impacts or any resulting adverse impacts to Steptoe Valley 
crescentspot populations. Also see the ``Summary of Common Threats'' 
section for information pertaining to water development, agriculture, 
livestock grazing, and climate change as potential threats.
    Therefore, based on our evaluation of the information in the 
petition and our files, we have determined that the petition does 
present substantial information to indicate that listing the Steptoe 
Valley crescentspot may be warranted due to the present or threatened 
destruction, modification, or curtailment of its habitat or range 
resulting from water development. During our status review of this 
subspecies, we will further investigate these and other potential 
threats.


[[Page 61552]]


    Factors B and C:
Information Provided in the Petition
    The petition states that it is not known whether overutilization, 
disease, or predation is a threat to this subspecies (WildEarth 
Guardians 2010, p. 8). Austin (1998c, p. 577) indicates 39 males and 10 
females were collected between 1981 and 1989, as referenced in the 
petition.
Evaluation of Information Provided in the Petition and Our Files
    The petition does not provide information that overutilization, 
disease, or predation has negatively impacted the subspecies. While the 
petition's referenced material provides some information about known 
numbers of collections, the petition does not provide any information 
about the population sizes or trends during this time period. Given the 
low number of individuals collected over a 8-year time span, the length 
of time since these collections were made, and the lack of information 
about the relative impact to the population, the petition does not 
provide substantial information to indicate that collection may be a 
threat to the subspecies. We have no information in our files related 
to overutilization, disease, or predation for this subspecies. Also see 
the ``Summary of Common Threats'' section for information pertaining to 
overutilization, disease, and predation as potential threats.
    Based on our evaluation of the information provided in the petition 
and our files, we have determined that the petition does not present 
substantial information to indicate that listing the Steptoe Valley 
crescentspot may be warranted due to Factor B (overutilization for 
commercial, recreational, scientific, or educational purposes) or 
Factor C (disease or predation). However, during our status review of 
this subspecies, we will further investigate whether these potential 
threats are impacting the Steptoe Valley crescentspot.

    Factor D:
Information Provided in the Petition
    The petition asserts that existing regulatory mechanisms are 
inadequate to protect this subspecies (WildEarth Guardians 2010, pp. 8, 
40). The petition states that the BLM lists the Steptoe Valley 
crescentspot as a sensitive species (BLM 2007a, p. J-7). This 
designation can offer it some conservation consideration.
Evaluation of Information Provided in the Petition and in Our Files
    We have determined that water development may be a threat to the 
Steptoe Valley crescentspot by adversely impacting its habitat, as 
discussed in Factor A. Thus, we have determined that the petition does 
present substantial information to indicate that listing the Steptoe 
Valley crescentspot may be warranted due to the inadequacy of existing 
regulatory mechanisms pertaining to groundwater permitting and the 
possible overcommitment of groundwater resources in Steptoe Valley. 
Also see the ``Summary of Common Threats'' section for information 
pertaining to the inadequacy of existing regulatory mechanisms as a 
potential threat. During our status review for this subspecies, we will 
further investigate this and other potential threats and whether 
existing regulatory mechanisms may be inadequate.

    Factor E:
Information Provided in the Petition
    The petition mentions limited range and small population numbers as 
threats to this subspecies (WildEarth Guardians 2010, pp. 10-11, 40).
Evaluation of Information Provided in the Petition and in Our Files
    The petition does not present, nor do we have specific information 
in our files related to, population numbers, sizes, or trends for the 
Steptoe Valley crescentspot. The petition does not provide information 
on chance events or other threats to the subspecies and connect them to 
a possibly restricted range or small population numbers or the 
potential for such threats to occur in occupied habitats in the future. 
Since this subspecies is distributed over more than one population, its 
extinction vulnerability due to stochastic events may be reduced. In 
the absence of this information and connection, we do not consider 
small population numbers or limited range by themselves to be threats 
to this subspecies. Also see the ``Summary of Common Threats'' section 
for information pertaining to limited distribution and small population 
size as potential threats.
    Based on the evaluation of the information provided in the petition 
and our files, we have determined that the petition does not present 
substantial information to indicate that listing the Steptoe Valley 
crescentspot may be warranted due to other natural or manmade factors 
affecting the species' continued existence. However, during our status 
review of this subspecies, we will further investigate whether 
biological vulnerability is a threat to the Steptoe Valley 
crescentspot.
White River Valley Skipper (Hesperia uncas grandiosa)
    We accept the characterization of the White River Valley skipper as 
a valid subspecies based on its description by Austin and McGuire 
(1998, p. 778). The White River Valley skipper flies during June, July, 
and August (Austin and McGuire 1998, p. 778; Austin et al. 2000, p. 4). 
The apparent larval host plant is Juncus mexicanus (Mexican rush) 
(Austin and Leary 2008, p. 11).
    The White River Valley skipper's type locality is a narrow marshy 
area in the White River channel located 1 mi (1.6 km) north of the Nye 
County boundary in White Pine County, Nevada (Austin and McGuire 1998, 
p. 778; NNHPD 2008). Other areas where the subspecies is known include 
alkaline Distichlis spicata flats in the White River Valley from 
Sunnyside (Nye County) and from Big Smokey Valley (northern Nye County) 
(Austin and McGuire 1998, p. 778). In 1998, Austin and McGuire (1998, 
pp. 778-779) tentatively included populations from Spring Valley (White 
Pine County) and Lake Valley (Lincoln County), Nevada, in this 
subspecies. The NNHP database (2009, p. 7) indicates one occurrence in 
Nevada, but its location is not identified. The subspecies has been 
observed at Ruppes Place/Boghole, White River Valley, White Pine and 
Nye Counties (NNHP 2006, p. 47). 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 (Ecological Sciences, Inc. 2007, p. 28). This location is near 
other areas where the subspecies has been previously documented, and is 
not considered to be a significant range extension (Ecological 
Sciences, Inc. 2007, p. 28).

    Factor A:
Information Provided in the Petition
    The petition asserts that water development, land development, 
rechannelization of the White River, overgrazing, and climate change 
may impact this subspecies (WildEarth Guardians 2010, pp. 38-40). The 
petition provides information that Ruppes Place/Boghole is considered 
of ``highest conservation priority'' by the NNHP (2006, p. 12). The 
NNHP also identified sites in the upper and lower White River Valley, 
including Ruppes Place/Boghole, as ``priority wetland areas'' (NNHP 
2007, p. 26). Fifty percent of the springs and brooks in the upper 
White River (which includes Ruppes

[[Page 61553]]

Place/Boghole) have been eliminated, converted to other land uses, or 
degraded (NNHP 2007, p. 44). Fifty percent of the springs and brooks in 
the lower White River (which includes Sunnyside) have been converted to 
other land uses or degraded (NNHP 2007, p. 44).
    The petition also provides information that several wetland areas 
in Big Smoky Valley are considered high-priority wetlands by the NNHP 
(2007, p. 25). Wetlands, springs, and brooks in Big Smoky Valley have 
been eliminated, converted to other land uses, or degraded by 60 
percent (NNHP 2007, p. 35). The moderate-to-high stressors impacting 
wetland areas in the White River and Big Smoky Valleys include water 
diversion/development, groundwater pumping, hydrogeomorphic 
modification, land development, agriculture, livestock grazing, mining, 
nonnative species, and energy development (NNHP 2007, pp. 35, 44). The 
petition implies that these activities are negatively impacting the 
White River Valley skipper in the White River and Big Smokey Valleys. 
Threats mentioned by other sources specifically in relation to this 
subspecies include overgrazing, rechannelization of the White River, 
and water table drawdown (NatureServe 2009e, p. 2).
    The proposed SNWA groundwater development project is predicted to 
reduce flow to springs in southern White River Valley by 50 percent in 
15 years (Deacon 2007, p. 1), as referenced in the petition. This 
reduction could impact Juncus mexicanus, the apparent host plant for 
the White River Valley skipper, and which grows in moist habitats 
(Austin and Leary 2008, p. 11; WildEarth Guardians 2010, p. 39).
Evaluation of Information Provided in the Petition and Our Files
    Information provided in the petition and available in our files 
suggests that overcommitment of groundwater could result in adverse 
impacts to aquatic habitats and thus impact the White River Valley 
skipper, especially its apparent larval host plant, Juncus mexicanus, a 
plant usually found in wetlands (Reed 1988, pp. 8, 10). We have 
information in our files that the perennial yield of the White River 
hydrographic area (207) is 37,000 afy (45,640,000 m\3\/year), 
and there are 31,699 afy (39,100,000 m\3\/year) committed (NDWR 2010); 
thus, permitted groundwater rights are approaching but do not exceed 
the estimated average annual recharge. However, SNWA is proposing to 
withdraw groundwater from the Cave Valley hydrographic area 
(180) (SNWA 2008, p. 1-1) (NDWR 2010). There is evidence for a 
hydrologic connection suggesting that groundwater may flow between Cave 
Valley and White River Valley (NDWR 2008, pp. 16-17). When groundwater 
extraction exceeds aquifer recharge, it may result in surface water-
level decline, spring drying, and degradation or loss of aquatic 
habitat (Zektser et al. 2005, pp. 396-397). We have additional 
information in our files that indicates water diversions along the 
White River and other habitat disturbances may impact the White River 
Valley skipper (Austin et al. 2000, p. 4), though no specifics are 
provided.
    The petition does not provide, nor do we have in our files, 
specific, supporting information to indicate that the White River 
Valley skipper is impacted from land development, rechannelization, 
livestock grazing, or climate change in the White River and Big Smokey 
Valleys. Also see the ''Summary of Common Threats'' section for 
information pertaining to water development, agriculture, livestock 
grazing, and climate change as potential threats.
    Based on our evaluation of the information provided in the petition 
and in our files, we have determined that the petition does present 
substantial information to indicate that listing of the White River 
Valley skipper may be warranted due to the present or threatened 
destruction, modification, or curtailment of its habitat or range 
resulting from water development which may negatively impact its larval 
host plant. During our status review for this subspecies, we will 
further investigate these and other potential threats.

    Factors B and C:
Information Provided in the Petition
    The petition states that it is not known whether overutilization, 
disease, or predation is a threat to this subspecies. According to 
Austin and McGuire (1998, p. 778), 20 males and 14 females were 
collected between 1984 and 1989, as referenced in the petition.
Evaluation of Information Provided in the Petition and Available in Our 
Files
    The petition does not provide information that overutilization, 
disease, or predation has negatively impacted the subspecies. While the 
petition's referenced material provides information about known numbers 
of collections, it does not provide any information about the 
population sizes or trends during this time period. Given the low 
number of individuals collected over a 5-year time span, the length of 
time since these collections were made, and the lack of information 
about the relative impact to the population, the petition does not 
provide substantial information to indicate that collection may be a 
threat to the subspecies. We have no information in our files related 
to overutilization, disease, or predation for this subspecies. Also see 
the ``Summary of Common Threats'' section for information pertaining to 
overutilization, disease, and predation as potential threats.
    Based on our evaluation of the information provided in the petition 
and our files, we have determined that the petition does not present 
substantial information to indicate that listing the White River Valley 
skipper may be warranted due to Factor B (overutilization for 
commercial, recreational, scientific, or educational purposes) or 
Factor C (disease or predation). However, during our status review of 
this subspecies, we will further investigate these potential threats.

    Factor D:
Information Provided in the Petition
    The petition asserts that existing regulatory mechanisms are 
inadequate to protect this subspecies (WildEarth Guardians 2010, pp. 8, 
40). The BLM lists this subspecies as a sensitive species (BLM 2007a, 
p. J-37) which can offer it some conservation consideration.
Evaluation of Information Provided in the Petition and in Our Files
    We have determined that water development may be a threat to the 
White River Valley skipper by adversely impacting its habitat as 
discussed in Factor A. Thus, we have determined that the petition and 
our files do present substantial information to indicate that listing 
the White River Valley skipper may be warranted due to the inadequacy 
of existing regulatory mechanisms as they pertain to groundwater 
permitting and the possible overcommitment of groundwater resources in 
White River Valley. Also see the ``Summary of Common Threats'' section 
for information pertaining to the inadequacy of existing regulatory 
mechanisms as a potential threat. During our status review for this 
subspecies, we will further investigate this and other potential 
threats to determine whether existing regulatory mechanisms may be 
inadequate.

    Factor E:

[[Page 61554]]

Information Provided in the Petition
    The petition indicates this subspecies may be vulnerable to small 
population numbers (WildEarth Guardians 2010, p. 40). Austin (1985, pp. 
125-126) indicates Hesperia uncas spp. appear to be restricted to the 
valleys where they occur. The petition suggests that isolated 
populations of the White River Valley skipper are probably unable to 
disperse or interconnect with other populations (WildEarth Guardians 
2010, p. 38).
Evaluation of Information Provided in the Petition and in Our Files
    The petition does not present, nor do we have specific information 
in our files, related to population sizes, numbers, or trends for the 
White River Valley skipper. The petition does not provide information 
on chance events or other threats to the subspecies and connect them to 
small population numbers or restricted range or the potential for such 
threats to occur in occupied habitats in the future. Since this 
subspecies is distributed over more than one population, its extinction 
vulnerability due to stochastic events may be reduced. In the absence 
of this information and connection, we do not consider small population 
numbers or restricted range by themselves to be threats to this 
subspecies. Also see the ``Summary of Common Threats'' section for 
information pertaining to limited distribution and small population 
size as potential threats.
    Based on evaluation of the information provided in the petition and 
our files, we have determined that the petition does not present 
substantial information to indicate that listing the White River Valley 
skipper may be warranted due to other natural or manmade factors 
affecting the species' continued existence. However, during our status 
review for this subspecies, we will further investigate whether 
biological vulnerability is a threat to this subspecies.

Finding

    On the basis of our determination under section 4(b)(3)(A) of the 
Act, we have determined that for 6 of the 10 subspecies (Carson Valley 
silverspot, Carson Valley wood nymph, Mattoni's blue butterfly, Mono 
Basin skipper, and two Railroad Valley skippers--H. u. fulvapalla and 
H. u. reeseorum) the petition does not present substantial scientific 
or commercial information indicating that listing throughout their 
entire range may be warranted.
    On the basis of our determination under section 4(b)(3)(A) of the 
Act, we have determined that for 4 of the 10 Great Basin butterflies 
(Baking Powder Flat blue butterfly, bleached sandhill skipper, Steptoe 
Valley crescentspot, and White River Valley skipper) the petition 
presents substantial scientific or commercial information indicating 
that listing throughout their entire range may be warranted.
    The petition presents substantial information indicating that the 
Baking Powder Flat blue butterfly may warrant listing due to threats 
under Factors A and D. The petition does not present substantial 
information indicating that the Baking Powder Flat blue butterfly may 
warrant listing due to current or future threats under Factors B, C, 
and E.
    The petition presents substantial information indicating that the 
bleached sandhill skipper may warrant listing due to threats under 
Factors A, D, and E. The petition does not present substantial 
information indicating that the bleached sandhill skipper may warrant 
listing due to threats under Factors B and C currently, or in the 
future.
    The petition presents substantial information indicating that the 
Steptoe Valley crescentspot may warrant listing due to threats under 
Factors A and D. The petition does not present substantial information 
indicating that the Steptoe Valley crescentspot may warrant listing due 
to threats under Factors B, C, and E currently, or in the future.
    The petition presents substantial information indicating that the 
White River Valley skipper warrant listing due to threats under Factors 
A and D. The petition does not present substantial information 
indicating that the White River Valley skipper may warrant listing due 
to threats under Factors B, C, and E currently, or in the future.
    Because we found that the petition presents substantial information 
indicating that listing 4 of the 10 Great Basin butterflies may be 
warranted, we are initiating a status review to determine whether 
listing these 4 subspecies under the Act is warranted.
    The ``substantial information'' standard for a 90-day finding 
differs from the Act's ``best scientific and commercial data'' standard 
that applies to a status review to determine whether a petitioned 
action is warranted. A 90-day finding does not constitute a status 
review under the Act. In a 12-month finding, we will determine whether 
a petitioned action is warranted after we have completed a thorough 
status review of the species, which is conducted following a 
substantial 90-day finding. Because the Act's standards for 90-day and 
12-month findings are different, as described above, a substantial 90-
day finding does not mean that the 12-month finding will result in a 
warranted finding.

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 and Ventura Fish and Wildlife Offices (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: September 20, 2011.
Gregory E. Siekaniec,
Acting Director, U.S. Fish and Wildlife Service.
[FR Doc. 2011-25324 Filed 10-3-11; 8:45 am]
BILLING CODE 4310-55-P