[Federal Register Volume 76, Number 192 (Tuesday, October 4, 2011)]
[Proposed Rules]
[Pages 61532-61554]
From the Federal Register Online via the Government Printing 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
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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.
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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