Federal Register, Volume 74 Issue 174 (Thursday, September 10, 2009)

[Federal Register Volume 74, Number 174 (Thursday, September 10, 2009)]
[Proposed Rules]
[Pages 46551-46557]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E9-21762]

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DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17

[FWS-R8-ES-2009-0047]
[MO 92210530083-B2]

Endangered and Threatened Wildlife and Plants; 90-Day Finding on
a Petition to List the Amargosa Toad (Bufo nelsoni) as Threatened or
Endangered

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Notice of 90-day 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 the Amargosa toad (Bufo nelsoni)
as threatened or endangered under the Endangered Species Act of 1973,
as amended (Act). We find that the petition presents substantial
scientific or commercial information indicating that listing this
species may be warranted. Therefore, with the publication of this
notice, we are initiating a status review to determine if listing the
Amargosa toad is warranted. To ensure that the status review is
comprehensive, we are soliciting scientific and commercial data and
other information regarding this species.

DATES: We made the finding announced in this document on September 10,
2009. To allow us adequate time to conduct this review, we request that
we receive information on or before November 9, 2009.

ADDRESSES: You may submit information by one of the following methods:
Federal eRulemaking Portal: http://www.regulations.gov. Follow the instructions for submitting comments.
U.S. mail or hand-delivery: Public Comments Processing,
Attn: FWS-R8-ES-2009-0047; Division of Policy and Directives
Management; U.S. Fish and Wildlife Service; 4401 N. Fairfax Drive,
Suite 222; Arlington, VA 22203.
We will not accept e-mail or faxes. We will post all information
received on http://www.regulations.gov. This generally means that we
will post any personal information you provide us (see the Information
Solicited section below for more details).

FOR FURTHER INFORMATION CONTACT: Robert D. Williams, Field Supervisor,
Nevada Fish and Wildlife Office, 4701 North Torrey Pines Drive, Las
Vegas, NV 89130, by telephone (702-515-5230), or by facsimile (702-515-
5231). Persons who use a telecommunications device for the deaf (TDD)
may call the Federal Information Relay Service (FIRS) at 800-877-8339.

SUPPLEMENTARY INFORMATION:

Information Solicited

When we make a finding that a petition presents substantial
information indicating that listing a species may be warranted, we are
required to promptly commence a review of the status of the species. To
ensure that the status review (12-month finding) is complete and based
on the best available scientific and commercial information, we are
soliciting information concerning the status of the Amargosa toad. We
request information from the public, other concerned governmental
agencies, Native American Tribes, the scientific community, industry,
or any other interested parties concerning the status of the Amargosa
toad. We are seeking information regarding:
(1) The species' historical and current status and distribution,
its biology and ecology, and ongoing conservation measures for the
species and its habitat.
(2) Information relevant to 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:

[[Page 46552]]

(a) The present or threatened destruction, modification, or
curtailment of the species' 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.
(3) Any proposed projects or development plans that may result in
increased water use in the Oasis Valley.
(4) Information on methods to control crayfish (Procambarus spp.)
in desert riparian systems.
(5) Information on effects of mosquitofish on eggs and larvae of
the Amargosa toad or other species of toad where mosquitofish are not
native.
(6) Data on surface water quality or groundwater monitoring in the
Oasis Valley, including transport or movement of environmental
contaminants from mining operations and the Nevada Test Site.
(7) Information on whether or not UV-B radiation is increasing in
the Oasis Valley and, if so, the effects of this increase on Amargosa
toads.
(8) Information as to any other threats to Amargosa toads asserted
in the petition.
If we determine that listing the Amargosa toad is warranted, it is
our intent to propose critical habitat to the maximum extent prudent
and determinable at the time we propose to list the species. Therefore,
with regard to areas within the geographical range currently occupied
by the Amargosa toad, we also request data and information on what may
constitute physical or biological features that are essential to the
conservation of the species, where these features are currently found,
and whether any of these features may require special management
considerations or protection. In addition, we request data and
information regarding whether or not there are 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 the species is proposed for listing, and why
such habitat meets the requirements of the Act.
Please note that submissions merely stating support for or
opposition to the action under consideration without providing
supporting information, although noted, will not be considered in
making a determination, as section 4(b)(1)(A) of the Act directs that
determinations as to whether any species is an endangered or threatened
species must be made ``solely on the basis of the best scientific and
commercial data available.'' Based on the status review, we will issue
a 12-month finding on the petition, as provided in section 4(b)(3)(B)
of the Act.
You may submit your information concerning this status review by
one of the methods listed in the ADDRESSES section. We will not
consider submissions sent by e-mail or fax or to an address not 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 website. If your submission is made via a hardcopy
that includes personal identifying information, you may request at the
top of your document that we withhold this 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 materials we receive, as well as supporting
documentation we used in preparing this finding, will be available for
public inspection on http://www.regulations.gov, or by appointment
during normal business hours, at the U.S. Fish and Wildlife Service,
4701 North Torrey Pines Drive, Las Vegas, NV.

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 at
the time we make the determination. 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 commence a status review of the species.
On February 27, 2008, we received a petition dated February 26,
2008, from the Center for Biological Diversity and Public Employees for
Environmental Responsibility (PEER; hereinafter referred to as
``petitioners'') requesting that the Amargosa toad be listed as
endangered or threatened under the Act. The petition clearly identified
itself as such and included the requisite identification information
for the petitioners, as required in 50 CFR 424.14(a). In a letter to
the petitioners dated May 1, 2008, we responded that we had reviewed
the petition and found that an emergency listing was not warranted. We
also stated that, although we were currently required to complete a
significant number of listing and critical habitat actions, we
anticipated making an initial finding on the petition during Fiscal
Year 2008. However, due to unforeseen delays, we were not able to
complete the finding at that time. This notice constitutes our initial
finding on the petition.

Previous Federal Actions

On August 2, 1977, the Service included the Amargosa toad on a list
of amphibians that we were reviewing to determine whether those species
should be proposed for listing as endangered or threatened (42 FR
39121). Subsequently, beginning in 1982, we assigned the Amargosa toad
as either a category 1 or category 2 candidate species under the Act
(47 FR 58454, December 30, 1982; 50 FR 37958, September 18, 1985; 54 FR
554, January 6, 1989; 56 FR 58804, November 21, 1991; 59 FR 58982,
November 15, 1994). A category 1 species was a taxon for which the
Service has substantial information on hand to support the biological
appropriateness of proposing to list as endangered or threatened under
the Act. A category 2 species was a taxon for which the Service has
information indicating that proposing to list the species as endangered
or threatened is possibly appropriate, but that information is not
conclusive data on biological vulnerability or threats that would
support a proposed listing.
On September 21, 1994, the Service received a petition from the
Biodiversity Legal Foundation of Boulder, Colorado, requesting
emergency listing of the Amargosa toad as endangered. At the time we
received the petition, the Amargosa toad was a category 1 candidate
species. On March 23, 1995, we announced our 90-day finding that the
petitioned action may be warranted and initiated a status review of the
species (60 FR 15280). On July 26, 1995,

[[Page 46553]]

the Service recommended removal of the Amargosa toad from category 1
candidate status based on information we obtained during the status
review. On February 28, 1996 (61 FR 7596), we removed the Amargosa toad
from candidate status. On March 1, 1996, we announced our 12-month
finding that listing the Amargosa toad as endangered or threatened was
not warranted (61 FR 8018).

Species Information

Taxonomy and Description

The Amargosa toad is a member of the family Bufonidae which
includes North American true toads. Stejneger (1893, cited in Lannoo
2005, p. 427) described the Amargosa toad as Bufo boreas nelsoni, a
subspecies of the western toad (Bufo boreas). Savage (1959, pp. 251-
254) was the first to refer to the Amargosa toad as Bufo nelsoni in
accordance with the rules of the International Code of Zoological
Nomenclature. Feder (1997, cited in Lannoo 2005, p. 428) diagnosed Bufo
nelsoni by allozymic data and was the first to publish species rank for
the Amargosa toad. Mitochondrial DNA analyses by Goebel (1996, cited in
Lannoo 2005, p. 429) are consistent with species status for the
Amargosa toad. In 2002, Bufo nelsoni was listed as a full species on
the Integrated Taxonomic Information System database compiled by the
Smithsonian Institution with the highest credibility rating by their
Taxonomic Working Group (Lannoo 2005, p. 427).
Adult male Amargosa toads are typically 1.6 to 2.7 inches (in.) (42
to 68 millimeters (mm)) snout-vent length, females typically 1.8 to 3.5
in. (46 to 89 mm) snout-vent length (Nevada Department of Wildlife
[NDOW] 2000a, p. A-2). The dorsal body of the Amargosa toad has three
paired rows of tubercles, or wart-like skin projections, with brown
center coloration. The back has black speckling or asymmetrical spots.
Background coloration ranges from almost black to brownish or buffy
olive and may vary considerably among individual toads in the same
population. A light mid-dorsal stripe occurs along the backbone. The
large, wart-like parotid glands located behind the eye are tawny to
olive. Underneath, the Amargosa toad is whitish or pale olive with
scattered black spots that merge above the legs to form the appearance
of ``pants.''

Historical and Current Range

Amargosa toads are endemic to Oasis Valley in southern Nye County,
Nevada. The area occupied by the Amargosa toad is isolated with no
known or probable connections to members of the western toad complex
(NDOW 2000a, p. A-1). The nearest known record for a western toad is
approximately 35 linear miles (56 kilometers (km)) away at Furnace
Creek in Death Valley National Park, California, where an introduced
population of western toad occurs. The historical and current range of
the Amargosa toad is estimated to be a 10-mile (16-km) stretch of the
Amargosa River and nearby spring systems roughly between the towns of
Springdale and Beatty. In 1996, the Amargosa Toad Working Group (ATWG)
was organized to provide recommendations for management and
conservation of the Amargosa toad. The ATWG consists of representatives
of the Service, NDOW, Nevada Department of Conservation and Natural
Resources, Bureau of Land Management (BLM), Nye County and local
community, the University of Nevada at Reno, and other stakeholders. In
2007, the ATWG prepared a map of all known and potential habitat for
the species, including potential movement corridors, and posted the map
on the Internet at: http://www.fws.gov/nevada/nv%5Fspecies/amargosa_toad.html. The total amount of known and potential Amargosa toad
habitat delineated on the ATWG map is 8,440 acres (ac) (3,416 hectares
(ha)).

Life History and Ecology

Amargosa toad habitat requirements for breeding and population
recruitment include the presence of open, ponded or flowing water, with
riparian vegetative cover in an early to intermediate successional
stage to form a partial canopy for shade with minimal emergent
vegetation at the water's edges. Immature (metamorphs or toadlets) and
adult Amargosa toads are dependent upon the areas described above as
well as areas they can use for shelter, including burrows, debris
piles, spaces under logs or rocks, or areas of dense vegetation (NDOW
2000a, p. A-2). Adult toads also require adjacent vegetated uplands for
nocturnal foraging. Upland habitat typically consists of Mojave and
Great Basin desert vegetation with leaf litter, rock outcrops, rodent
burrows, woody debris, and open areas that are sparsely vegetated.
Dense vegetation and advanced successional stages of riparian
vegetation appear to limit habitat suitability and occupancy by all
life stages, particularly where open water is not present (NDOW 2000a,
p. A-2).
The breeding season for the Amargosa toad begins in mid-February
and may extend into July during which time adults congregate at
breeding sites. Jones (2004, p. 19) found 82 percent of clutches were
laid from February 27 to March 23 in the 2001 season. Eggs are
deposited in strings among vegetation in shallow water. A female may
lay up to 6,000 eggs in a single clutch. The eggs typically develop
into larvae (tadpoles) within 1 to 2 weeks, but as quickly as 3 days in
thermal waters (NDOW 2000a, p. A-2). Larvae are blackish with silvery
speckles, rounded tail tips, and translucent tail fins. Larvae feed on
algae, decaying plant material, and organic detritus that is suspended
in the water column or on the substrate. Larvae may be swept downstream
if a current is present. Larval mortality may be very high, although
recruitment estimates have not been made (CBD and PEER 2008, p. 10).
Amargosa toad tadpoles require relatively open water that persists long
enough for the completion of metamorphosis and development into
toadlets at which time they leave the water. Tadpoles metamorphose into
toadlets in about 4 to 8 weeks, though development is highly variable
depending on water temperature and site conditions (Jones 2004, p. 7).
Predation and early desiccation of wetlands needed for breeding may
destroy an entire breeding effort. Amargosa toads are believed to
typically live 3 to 4 years in the wild, but a toad marked in 1998 was
recaptured in 2008.
Amargosa toads may be active any time of the year. Toads eat
invertebrates including spiders, scorpions, ants, harvester ants,
wasps, beetles, flies, grasshoppers, stink bugs, water striders, damsel
flies, mosquitoes, mites, and snails. They use their sticky tongue to
grab prey items in a sit-and-wait predator strategy (CBD and PEER 2008,
p. 11).
The mean home range of adult Amargosa toads has been studied at the
Torrance Ranch site and at Amargosa River Narrows. Home ranges at these
sites are estimated to be approximately 1.5 ac (0.6 ha), with no
difference between males and females (Jones 2004, p. 48). Rare
movements occur over 0.8 mile (1.3 km) between breeding sites along the
Amargosa River and 0.5 mile (0.8 km) across uplands (NDOW 2000b, p. 9).
During rain events, toad movements are not always confined to riparian
corridors and reports exist of Amargosa toads moving over upland ridges
(Jones 2004, p. 49). However, significant genetic differentiation of
Amargosa toads among sites suggests Amargosa toads do not make
extensive use of upland habitat for movement or migration (Simandle
2006, p. 38). Amargosa toads are attracted to

[[Page 46554]]

disturbed areas where they forage and breed (NDOW 2000b, pp. 7-8 and
19), and seemingly co-exist with humans as indicated by survey data
collected at developed study sites (urban and residential).
Predators of toads include common raven (Corvus corax), white-faced
ibis (Plegadis chihi), great egret (Ardea alba), snowy egret (Egretta
thula), great blue heron (Ardea herodias), red-tailed hawk (Buteo
jamaicensis), red-shouldered hawk (Buteo lineatus), spotted sandpiper
(Actitis macularius), American robin (Turdus migratorius), American
badger (Taxidea taxus), crayfish (Procambarus spp.), and various fish
species (CBD and PEER 2008, p. 11).

Status

Since 1998, the Amargosa toad has been classified as a Protected
Species by the State of Nevada. No Federal protection is currently
afforded the species other than designation as a Special Status Species
by the BLM. Conservation and management oversight for the Amargosa toad
is provided through the ATWG. The ATWG is comprised mostly of
biologists, managers, and private landowners with a common interest in
Amargosa toad conservation. The Amargosa Toad Conservation Agreement
and Strategy was completed in 2000 (CA/S) (NDOW 2000a, pp. 1-12) and
provides management and conservation guidance for the Amargosa toad.
Efforts to update the CA/S were initiated at the November 7, 2007,
meeting of the ATWG.
In 1998, the Nevada Department of Wildlife (NDOW) initiated a long-
term population monitoring program for the Amargosa toad using mark/
recapture methods at key sites. The study involves capture and marking
(with implanted tags) of all adult Amargosa toads found that are 2 in.
(50 mm), or greater in length. As of November 2007, a total of 5,666
Amargosa toads had been captured and tagged since 1998. The 2007
estimate for the number of toads 2 in. (50 mm) or greater in length
from all surveyed sites is 5,179, which is 13 percent less than the
estimate for 1998 through 2006 (Hobbs 2007, p. 1). Further, additional
populations of toads may occur on unsurveyed sites on private land
(NDOW 2000b, p. 18).
Simandle (2006, p. 42) determined that Amargosa toads meet the
criteria and expectations of metapopulations. This means that occupied
habitats, unoccupied but suitable habitats, and intervening habitat
that may be occasionally used during infrequent migration events should
all be considered as conservation priorities. Rare events such as
intense floods demonstrate that these are dynamic, disturbance-
dependent ecological systems upon which the Amargosa toad depends.
Events such as floods may simultaneously destroy existing occupied
habitat, create new suitable habitat, and facilitate infrequent
movement among different sites.

Five Factor Evaluation

Section 4 of the Act, and its implementing regulations at 50 CFR
424, set forth the criteria and procedures for adding species to the
Federal Lists of Endangered and Threatened Wildlife and Plants. The
Service determines whether a species is an endangered or threatened
species due to one or more of the following 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 making this 90-day finding, we evaluated whether information
regarding the Amargosa toad, as presented in the petition and other
information available in our files at the time of the petition review,
meets the definition of substantial information as stated in 50 CFR
424.14(b)(1), indicating that the petitioned action may be warranted.
Our evaluation of this information is presented below.

Factor A.

Present or Threatened Destruction, Modification, or Curtailment of the
Species' Habitat or Range

The petition outlines numerous assertions regarding the present or
threatened destruction, modification, or curtailment of the Amargosa
toad's habitat or range. Several assertions point to Amargosa toad
habitat being threatened by proposed Federal land sales and by
development projects on private land. The petitioners claim that
federal land proposed for sale and private lands subject to development
encompass the majority of the range of the Amargosa toad (CBD and PEER
2008, pp. 3, 19, and 29). The petition states that threats to the
Amargosa toad resulting from federal land sales are the development
that would take place on these and the surrounding private lands, and
the increased demand for groundwater to support that development (CBD
and PEER 2008, pp. 3, 17, and 20).
The petition raises the issue of potential development plans for
the Town of Rhyolite that would include the need for water (CBD and
PEER 2008, p. 20). Indian Spring has been identified as a potential
water extraction site that would support Rhyolite development. The
petition states that if this were to occur, it would likely adversely
affect the water table at that site.
The petition also states that the proposed Reward Mine on BLM land
has the potential to affect groundwater in the area. The Reward Mine is
approximately 3 miles (4.8 km) southeast of the Amargosa River at the
Narrows, south of Beatty. The mine operations would use up to 287 acre-
feet of groundwater per year over a period of 6 years (John Shomaker
and Associates, Inc. 2008, p. 1). The petitioners claim that proposed
water withdrawal potentially may create a cone of depression that could
lower water levels upstream and impact toad habitat. The February 2008
analysis provided by BLM on the Reward Mine indicates water for
operations would be provided by a well in alluvium next to the Amargosa
River (John Shoemaker & Associates Inc. 2008, p. 1). The petitioners
assert the combination of river water and local groundwater extracted
from the well could lower groundwater levels in Oasis Valley
(particularly southern Oasis Valley); however, the petitioner did not
provide any support for these assertions.
The petitioners assert that lowering of the water table from
increased groundwater use could seriously impact toad habitat (CBD and
PEER 2008, p. 17). Further, they claim that portions of the Amargosa
River may have become dewatered from overuse by humans (CBD and PEER
2008, p. 17). A detailed analysis of the impacts of groundwater and
surface water withdrawals on water levels in the Amargosa River would
be required to demonstrate the above effects. There is no indication in
our files or submitted with the petition that such an analysis has been
completed. However, we have in our files a 1998 ruling on an
application for groundwater withdrawal in the Oasis Valley issued by
the Nevada State Engineer (NSE). This ruling recognized a high degree
of connection between groundwater and surface water in Oasis Valley
(NSE Ruling 4669). The NSE found that combined groundwater and surface
water allocations significantly exceeded the current estimate of
perennial yield in the basin. Proposed land uses and development in and
near the area of Oasis Valley could lead to additional groundwater
allocations, accompanied by a reduction in

[[Page 46555]]

Amargosa toad habitat through a lowering of local groundwater levels. A
small decrease in groundwater levels in Oasis Valley could lead to a
significant reduction in the area of open pools of water at springs,
along spring branches, or along the Amargosa River (particularly during
dry summer months), all of which provide habitat for the Amargosa toad
(Braumiller 2008, p. 1). Therefore existing and future water use in the
Oasis Valley may pose a threat to the Amargosa toad.
Other potential threats identified by the petitioners include
alterations of the riparian corridor that may affect toad movements and
habitat connectivity; habitat loss and fragmentation resulting from
proposed projects including flood control projects, a railroad, and a
mineral material site; overgrowth of vegetation as a result of fencing;
feral burro and livestock effects on springs and toads; direct
mortality associated with roads and highways; and off-highway vehicle
(OHV) use.
The petitioners generally describe the potential effects that could
result from flood control projects (CBD and PEER 2008, pp. 17 and 20).
However, the petitioners do not provide information on any specific
flood control projects that may threaten the species or its habitat,
and the Service is unaware of any proposed flood control actions that
would alter the Amargosa River.
The petitioners state that construction of a new railroad, as
proposed by the U.S. Department of Energy to transport nuclear waste to
Yucca Mountain, may cross the northernmost portion of the Oasis Valley,
north of Colson pond, disturbing approximately 20 ac (8 ha) of Amargosa
toad habitat (CBD and PEER 2008, p. 18). Although habitat is suitable,
Amargosa toads are not known to occur in this area (ATWG 2006, pp. 1-
2).
Vegetation overgrowth and use of springs by feral burros and cattle
are other land management issues raised by the petitioners that may
result in degraded habitat and depressed Amargosa toad numbers (CBD and
PEER 2008, pp. 17-18, 21 and 23-25). Fencing has been installed at the
Crystal and Indian springs sites to exclude feral burros. While burros
and livestock (ungulates) may trample Amargosa toad eggs and larvae,
light to moderate disturbance is important to Amargosa toads (ATWG
2005, p. 2). In the absence of disturbance, vegetation grows
uncontrolled and reduces open areas necessary for Amargosa toads.
Intensive and uncontrolled use of Amargosa toad habitat by ungulates
may threaten the species by resulting in habitat degradation and
potential loss of individual Amargosa toads; however, light to moderate
use may be beneficial to the Amargosa toad. Targeted grazing on the
Torrance Ranch by The Nature Conservancy improved habitat, and Amargosa
toads responded positively as indicated by use of the area by Amargosa
toads for feeding and breeding. Complete removal of ungulates could
lead to overgrowth of vegetation, and may pose a more serious threat to
the Amargosa toad than moderate ungulate use.
The petitioners claim that OHV activity has been increasing around
the Beatty area and results in decreased habitat quality, loss of
riparian habitats, and direct mortality of Amargosa toads (CBD and PEER
2008, pp. 21 and 27). Most OHV use in the Beatty area, including the
Terrible's 200 Las Vegas to Reno race, occurs during the daytime when
toads are likely sheltering. OHVs are used by community residents
within the town limits of Beatty mostly along existing roads and
trails. However, OHV travel within the river corridor, washes, or other
areas used by toads for breeding or for sheltering during daylight
hours may impact Amargosa toads, particularly eggs and tadpoles that
are known to occur in road depressions. Although the extent of impacts
to the Amargosa toad as a result of OHV use is largely unknown, we
believe this current OHV use could pose a threat to the Amargosa toad.
In summary, we find that the information provided in the petition,
as well as information in our files, presents substantial scientific or
commercial information indicating that listing the Amargosa toad as
threatened or endangered may be warranted due to the present or
threatened destruction, modification, or curtailment of its habitat or
range, including existing and future water development, use of
groundwater to support land development, overgrowth of vegetation,
excessive habitat use by ungulates, and OHV use in toad habitat. We
will investigate whether there are additional potential threats to the
Amargosa toad related to Factor A during our status review.

Factor B.

Overutilization for Commercial, Recreational, Scientific, or
Educational Purposes

The petitioners state that there is no evidence that scientific
research has resulted in negative consequences on studied populations
of the Amargosa toad (CBD and PEER 2008, p. 22). We have no information
in our files that indicates overutilization for commercial,
recreational, scientific, or educational purposes is a threat to the
Amargosa toad. However, we will further investigate whether
overutilization for commercial, recreational, scientific, or
educational purposes is a potential threat to the toad during our
status review.

Factor C.

Disease or Predation

The petitioners did not present evidence, and no evidence exists in
our files, that disease may be a threat to the Amargosa toad at this
time. However, we will further investigate whether disease is a
potential threat to the toad during our status review.
The petitioners claim that exotic species or nonnative predators
and competitors, including nonnative crayfish (Procambarus spp.),
largemouth bass (Micropterus salmoides), nonnative trout (Oncorhynchus
spp.), black bullhead catfish (Ictalurus melas), mosquitofish (Gambusia
affinis), and nonnative bullfrogs (Rana catesbeiana), are a serious
threat to the Amargosa toad. Since their introduction in the mid-1980s,
nonnative crayfish have become established along most of the Amargosa
River and springs occupied by the Amargosa toad, and occur in large
numbers (CBD and PEER 2008, p. 3). Crayfish consume toad eggs and
larvae, and were located in 7 of 11 sites surveyed during a study (CBD
and PEER 2008, p. 23; Jones 2004, pp. 24-25). Bass are known to occur
in at least one pond on private property in Oasis Valley, but there is
no information in our files to support the claim that trout currently
occur in Oasis Valley. Black bullhead catfish are known at one pond
that is also occupied by Amargosa toads. Catfish and toads have co-
occurred at this site for at least 9 years. Mosquitofish have been
introduced into waters of Oasis Valley and occur at most sites occupied
by toads. Mosquitofish have been observed to remove and consume eggs of
the arroyo toad (Bufo californicus; Lannoo 2005, p. 399) and may also
prey on Amargosa toad eggs. It is conceivable that nonnative predators
have an impact on Amargosa toads; however, the overall effects of these
introduced aquatic species specifically to the Amargosa toad are
unknown.
In summary, we find that the information provided in the petition,
as well as information in our files, presents substantial scientific or
commercial information indicating that listing the Amargosa toad may be
warranted due to the threat of predation by introduced species.

[[Page 46556]]

Factor D.

Inadequacy of Existing Regulatory Mechanisms

The petitioners cite BLM's failure to protect the Amargosa toad
through designation of important toad habitat as an Area of Critical
Environmental Concern (ACEC) or through provision of a comparable level
of protection through other means (CBD and PEER 2008, pp. 19 and 27).
Further, they claim that the Town of Beatty and Nye County have failed
to cooperate in local community efforts to develop a conservation area
in Oasis Valley (CBD and PEER 2008, p. 20), and, therefore, that
Amargosa toad habitat on private land is threatened by potential
development which may proceed without conservation for the Amargosa
toad (CBD and PEER 2008, p. 19). Finally, the petitioners assert that
the State of Nevada fails to provide adequate protection for the
Amargosa toad through existing statutes particularly regarding permit
exemptions for residential groundwater use up to 1,800 gallons per day
and habitat threats on private lands (CBD and PEER 2008, pp. 20 and
28).
The petitioners also claim that BLM allows OHV racing near the
Crystal Springs exclosure and in a wash potentially used by Amargosa
toads. They further state that BLM usually does not enforce OHV
exclusion from riparian areas in Oasis Valley (CBD and PEER 2008, p.
27).
Finally, the petition claims that BLM failed to follow through with
habitat projects (CBD and PEER 2008, pp. 20 and 25) and the CA/S has
failed at protecting toad habitat and increasing toad populations (CBD
and PEER 2008, p. 27).
Water development may adversely affect areas occupied by Amargosa
toad. The State of Nevada permits exemptions for up to 1,800 gallons
per day for residential use, which may collectively result in a
substantial volume of groundwater withdrawal. The structure of State
water regulations and absence of sufficient data on groundwater and
surface water to support development without affecting toad habitat
constitutes a potential threat to the Amargosa toad. Further, the
Service is unaware of a final master plan that guides community
planning in concert with toad conservation. The Service acknowledges
that activities and potential development on private lands within Oasis
Valley are significant threats to the toad.
Near the Crystal Spring exclosure, BLM has approved OHV events that
occur over a 2-day period during the daytime when Amargosa toads are
sheltering. The BLM imposes permit conditions to minimize impacts to
the area. The Service is unaware of any information that indicates
these events or casual OHV use are threats to the Amargosa toad or that
BLM fails to enforce OHV exclusion from riparian areas. In 2008, BLM
chose an alternate route away from toad habitat for OHV events near
Crystal Spring.
Following a recent review of the CA/S, the ATWG concluded that
implementation of the CA/S was an overall success. While some projects
have not been completed, a number of important activities not
identified in the CA/S have been conducted. The updated CA/S will
include information on all accomplishments that benefit the toad. The
petition asserts that several habitat enhancement projects proposed in
the CA/S (CBD and PEER 2008, p. 20) were not completed, but these
projects will be revisited in the upcoming review of CA/S.
In summary, we find that the information provided in the petition,
as well as information in our files, does present substantial
scientific or commercial information indicating that listing the
Amargosa toad may be warranted due to the inadequacy of the existing
regulatory mechanisms, particularly State regulations that allow for
residential groundwater use up to 1,800 gallons per day without the
need for a permit and the lack of a final master plan for the Oasis
Valley.

Factor E.

Other Natural or Manmade Factors Affecting the Species' Continued
Existence

The petitioners assert that the Amargosa toad is particularly
vulnerable to extinction due to its exceedingly small range and small
population size; most of its range has been impacted by humans
(Simandle 2006, p. 14; Petition, pp. 16 and 29), and small populations
are particularly vulnerable to genetic drift. Information in our files
also suggests that the historical and current range of the Amargosa
toad is small, i.e., approximately 10 miles (16 km) long consisting of
8,440 ac (3,416 ha) centered on the Amargosa River and including
movement corridors among adjacent spring sites and the river. Small
population size and range, compounded by threats under Factor A, could
threaten the Amargosa toad. Therefore, we find that the information in
the petition and in our files presents substantial information that
small range and population size may be an important threat to the
Amargosa toad when combined with potential threats from development
identified in Factor A.
The petition states that species found in few locations, such as
the Amargosa toad, are susceptible to stochastic events such as fire or
floods (CBD and PEER 2008, p. 22). Controlled burns conducted on
Torrance Ranch in 2008 were successful at reducing vegetation and
improving toad habitat; toad reproduction was documented immediately
following the burn (ATWG 2008, p. 1). Flood events are a natural
disturbance and may benefit the Amargosa toad through periodic habitat
disturbances. We will further investigate whether susceptibility to
stochastic events is a potential threat to the toad during our status
review.
Radiation poisoning through groundwater contamination (from atomic
testing on the Nevada Test Site) was also cited by the petitioners (CBD
and PEER 2008, p. 21). The petitioners also assert that pollution of
unknown levels on private land is a threat to the Amargosa toad (CBD
and PEER 2008, p. 25). No information on groundwater connections or the
types, amounts, infiltration speed, or locations of pollution was
provided in the petition or exists in our files to support this claim
as an important threat to the Amargosa toad. However, we will further
investigate whether radiation poisoning through groundwater
contamination is a potential threat to the toad during our status
review.
Environmental factors, including global warming, were identified by
the petitioners as factors that could decrease habitat for the Amargosa
toad through drought. The petitioners also mentioned increased UV-B
radiation, which could weaken the Amargosa toad's immune system and
result in mortality from disease (CBD and PEER 2008, p. 22). As
acknowledged in the petition (CBD and PEER 2008, p. 23), disease has
not been observed in Amargosa toads, and no field observations of
Amargosa toad mortalities suggesting disease have been reported.
We acknowledged in Factor A that management of water resources to
meet the needs of the Amargosa toad is important for Amargosa toad
conservation. Environmental changes due to climate change, including
drought, could exacerbate the threats under Factor A. Therefore, we
find that the information in the petition and in our files presents
substantial information to indicate environmental changes due to
climate change could exacerbate threats under Factor A and combine to
threaten the Amargosa toad.

[[Page 46557]]

Finally, the petitioners claim that introduced, invasive trees have
become established along stretches of the Amargosa River and springs,
which may reduce prey and microhabitat available for the Amargosa toad
(CBD and PEER 2008, pp. 24 and 26). Since the CA/S was signed in 2000,
removal of invasive trees, tamarisk (Tamarix ramosissima) and Russian
olive (Elaeagnus angustifolia) has been ongoing and successful as a
joint effort involving State, Federal, and private landowners. Amargosa
toads are known to use areas underneath tamarisk and Russian olive
trees for feeding and sheltering. Tamarisk and Russian olive removal
efforts generally include replacement with native riparian species that
will provide the same function. We will further investigate whether
invasive trees are a potential threat to the toad during our status
review.
In summary, we find that the information provided in the petition
and in our files presents substantial scientific or commercial
information indicating that listing the Amargosa toad may be warranted
due to threats from other natural or manmade factors. These factors,
particularly small populations, small range size, and environmental
changes due to climate change, could exacerbate threats identified
under Factor A.

Finding

We have reviewed the petition and the literature cited in the
petition, and evaluated the information to determine whether the
sources cited support the claims made in the petition. We also reviewed
information that was readily available in our files. Based on our
evaluation of the information provided in the petition, and information
in our files, we find that the petition presents substantial scientific
information indicating that listing the Amargosa toad may be warranted.
Our process for making this 90-day finding under section 4(b)(3)(A)
of the Act is limited to a determination of whether the information in
the petition presents ``substantial scientific or commercial
information,'' which is interpreted in our regulations as ``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)).
Section 4(a) of the Act states the Secretary shall, by regulation
promulgated in accordance with subsection (b) of the Act, determine
whether any species is an endangered species or a threatened species
because of any of the five listing factors. Furthermore, regulations at
50 CFR 424.11(c) state a species shall be listed or reclassified if the
Secretary determines, on the basis of the best scientific and
commercial data available after conducting a review of the species'
status, that the species is endangered or threatened because of any one
or a combination of the five listing factors.
As described in our Five-Factor Evaluation above, the petitioners
presented substantial information indicating that the Amargosa toad may
be threatened throughout its entire range due to four of the five
listing factors described in the Act. Therefore, based on our
determination that the petitioned action may be warranted due to
substantial information presented under Factors A, C, D and E, we are
initiating a status review to determine whether listing the Amargosa
toad under the Act is warranted. We will address any other potential
threats during our status review. To ensure that the status review is
comprehensive, we are soliciting scientific and commercial information
regarding the Amargosa toad relevant to all five listing factors.
The ``substantial information'' standard for a 90-day finding
differs from the Act's ``best scientific and commercial data'' standard
that applies to a 12-month finding after a status review to determine
whether a petitioned action is warranted. A 90-day finding is not a
status assessment of the species and does not constitute a status
review under the Act. Our final determination as to whether a
petitioned action is warranted is not made until we have completed a
thorough status review of the species, which is conducted following a
positive 90-day finding. Because the Act's standards for 90-day and 12-
month findings are different, as described above, a positive 90-day
finding does not mean that the 12-month finding also will be positive.

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, Las Vegas, Nevada (see FOR FURTHER INFORMATION
CONTACT).

Author

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

Authority

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

Dated: August 26, 2009.
Daniel M. Ashe,
Acting Director, U.S. Fish and Wildlife Service.
[FR Doc. E9-21762 Filed 9-9- 09; 8:45 am]
BILLING CODE 4310-55-S