[Federal Register Volume 75, Number 138 (Tuesday, July 20, 2010)]
[Proposed Rules]
[Pages 42040-42054]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2010-17647]


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DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17

[FWS-R8-ES-2009-0047]
[92210-1111-0000 B2]


Endangered and Threatened Wildlife and Plants; 12-Month Finding 
on a Petition to List the Amargosa Toad as Threatened or Endangered

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Notice of 12-month petition finding.

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SUMMARY: We, the U.S. Fish and Wildlife Service (Service), announce a 
12-month finding on a petition to list the Amargosa toad (Anaxyrus 
nelsoni) as threatened or endangered and to designate critical habitat 
under the Endangered Species Act of 1973, as amended. After review of 
all available scientific and commercial information, we find that 
listing the Amargosa toad is not warranted at this time. However, we 
ask the public to submit to us any new information that becomes 
available concerning the threats to the Amargosa toad or its habitat at 
any time.

DATES: The finding announced in this document was made on July 20, 
2010.

ADDRESSES: This finding is available on the Internet at http://www.regulations.gov at Docket Number FWS-R8-ES-2009-0047. Supporting 
documentation we used in preparing this finding is available for public 
inspection, by appointment, during normal business hours at the U.S. 
Fish and Wildlife Service, Nevada Fish and Wildlife Office, 4701 N. 
Torrey Pines Dr., Las Vegas, NV. Please submit any new information, 
materials, comments, or questions concerning this finding to the above 
address.

FOR FURTHER INFORMATION CONTACT: Robert D. Williams, State Supervisor, 
Nevada Fish and Wildlife Office; by mail (see ADDRESSES); by telephone 
at 775-861-6300; or by facsimile at 775-861-6301mailto:. Persons who 
use a telecommunications device for the deaf (TDD) may call the Federal 
Information Relay Service (FIRS) at 800-877-8339.

SUPPLEMENTARY INFORMATION:

Background

    Section 4(b)(3)(B) of the Endangered Species Act of 1973, as 
amended (Act) (16 U.S.C. 1531 et seq.) requires that, for any petition 
to revise the Federal Lists of Endangered and Threatened Species that 
contains substantial scientific or commercial information that listing 
the species may be warranted, we make a finding within 12 months of the 
date of receipt of the petition. In this finding, we will determine 
that the petitioned action is: (1) Not warranted, (2) warranted, or (3) 
warranted, but the immediate proposal of a regulation implementing the 
petitioned action is precluded by other pending proposals to determine 
whether species are threatened or endangered, and expeditious progress 
is being made to add or remove qualified species from the Federal Lists 
of Endangered and Threatened Species. Section 4(b)(3)(C) of the Act 
requires that we treat a petition for which the requested action is 
found to be warranted but precluded as though resubmitted on the date 
of such finding, that is, requiring a subsequent finding to be made 
within 12 months. We must publish these 12-month findings in the 
Federal Register.

Previous Federal Actions

    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, we assigned the Amargosa toad as a category 1 
candidate species under the Act in 1982 (47 FR 58454, December 30, 
1982) and 1994 (59 FR 58982, November 15, 1994); and designated it as a 
category 2 candidate in 1985 (50 FR 37958, September 18, 1985); 1989 
(54 FR 554, January 6, 1989); and 1991 (56 FR 58804, November 21, 
1991). 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, 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).
    On February 27, 2008, we received a petition from the Center for 
Biological Diversity (CBD) and Public Employees for Environmental 
Responsibility (PEER), hereinafter referred to as ``petitioners,'' 
requesting that the Amargosa toad be listed as endangered or threatened 
and that critical habitat be designated 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 and we anticipated making an initial finding 
on the petition during Fiscal Year 2008. On March 11, 2009, we received 
a 60-day notice of intent to sue from CBD alleging violations of the 
Act because we did not publish our 12-month finding within 12 months of 
receiving the petition. On September 10, 2009, we published a 90-day 
finding stating the petition contained substantial information to 
indicate the petitioned action may be warranted, and we announced the 
initiation of a status review of the species (74 FR 46551).
    On April 26, 2010, CBD amended its Complaint in Center for 
Biological Diversity v. Salazar, U.S. Fish and Wildlife Service, Case 
No.: 1:10-cv-230-PLF (D.D.C.), adding an allegation that the Service 
failed to issue its 12-month petition finding on the Amargosa toad 
within the mandatory statutory timeframe. This notice constitutes the 
12-month finding on the February 27, 2008, petition to list the 
Amargosa toad as threatened or endangered with critical habitat.

Species Information

    In addition to the information provided below, refer to the 90-day 
finding (74 FR 46551) for additional information on the Amargosa toad.

[[Page 42041]]

Taxonomy and Species 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 concluded that the Amargosa toad warrants 
species status. 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 in 
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). Frost et al. (2006) 
moved North American toads from Bufo to Anaxyrus (Tschudi 1845, cited 
in Frost et al. 2006, p. 363), which was accepted in 2008 by the 
Committee on Standard and Scientific Names (Committee; Crother 2008, 
pp. 2-4). The Committee, sanctioned by the Society for the Study of 
Amphibians and Reptiles, the American Society of Ichthyologists and 
Herpetologists, and The Herpetologists' League, is tasked to develop 
standard English names and publish a list of the current scientific 
names of North American herpetofauna. This is considered the official 
list for those societies.
    Adult male Amargosa toads typically have a snout-vent length of 1.6 
to 2.7 inches (in.) (42 to 68 millimeters (mm)); for females it is 
typically 1.8 to 3.5 in. (46 to 89 mm) (Nevada Department of Wildlife 
(NDOW) 2000, p. A-2). The dorsal body of the Amargosa toad has three 
paired rows of wart-like skin projections called tubercles. Their backs 
have black speckling or asymmetrical spots. Background coloration 
ranges from almost black to brownish or pale yellow-brown or 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.''

Current and Historic Ranges

    Amargosa toads are endemic to the Amargosa River drainage in 
southwestern Nevada (Goebel et al. 2009, p. 210). Available historic 
accounts (Maciolek 1983a, p. 11) do not provide any specific indication 
of wider distribution. Toads that occur in downstream reaches of the 
Amargosa River corridor (e.g., Ash Meadows area) anecdotally exhibit 
some taxonomic similarities; however, they have not been identified as 
Amargosa toads. The area occupied by the Amargosa toad is isolated, 
with no known or probable connections to members of the western toad 
complex (NDOW 2000, p. A-1). The nearest known record for a western 
toad is approximately 35 linear miles (mi) (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 occurs within Oasis Valley, along an 
approximately 10-mi (16-km) stretch of the Amargosa River and nearby 
spring systems, roughly between the towns of Springdale and Beatty. 
Oasis Valley occurs along U.S. Highway 95 between Bullfrog Hills and 
the Nevada Test Site.
    In 2007, the Amargosa Toad Working Group (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_species/amargosa_toad.html. The total amount of 
known and potential Amargosa toad habitat delineated by the ATWG is 
approximately 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, and areas of dense vegetation (NDOW 
2000, p. A-2). Adult toads also require adjacent vegetated uplands for 
nocturnal foraging. 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 2000, p. A-2). Toads can be abundant in irrigated and 
disturbed areas.
    The breeding season for the Amargosa toad begins in mid-February 
and may extend into July, during which time adults congregate at 
breeding sites. A female toad may produce over 6,000 eggs in a single 
reproduction event (Altig 1987, p. 277; Heinrich 1995, p. 2). Amargosa 
toad tadpoles require relatively open water that persists long enough 
for the completion of metamorphosis and development into toadlets, 
which occur over approximately 30 days. Predation and early desiccation 
of wetlands needed for breeding may destroy an entire breeding effort. 
Although Amargosa toads typically live 4 to 5 years, individual toads 
are known to live up to 17 years based on data from NDOW's population 
monitoring program (Hobbs 2010, p. 1.).

Population Status and Trends

    In 1998, NDOW initiated a long-term population monitoring program 
for the Amargosa toad using mark-recapture methods at 11 sites of the 
18 known sites occupied by toads. The 11 sites are grouped into 4 
spatial areas described below (see distribution map available at http://www.fws.gov/nevada/nv_species/amargosa_toad.html). The monitoring 
program was identified in the Amargosa Toad Conservation Agreement and 
Strategy (CAS) as an conservation action (NDOW 2000, p. A-11) and 
involves capture and marking (with implanted tags) of all juvenile to 
adult age-class Amargosa toads found that are 2 in. (50 mm) or greater 
in length. The NDOW maintains a database on Amargosa toad population 
monitoring data as prescribed in the CAS (NDOW 2000, pp. A-12 and 13). 
As of November 2009, a total of 6,739 Amargosa toads had been captured 
and tagged. In 2009, captures increased 77 percent over 2008, with a 
total of 768 toads captured and tagged, 519 of which were captured for 
the first time. The 2009 population estimate for monitored sites is 
1,623, which is 13.6 percent less than the average of 1,826 for the 
period 1998 through 2008 (Hobbs 2009, p. 1). Unsuitable weather 
conditions during the 2007 and 2008 surveys may have resulted in lower 
than average toad activity (Figure 1; Hobbs 2009, p. 2). Habitat 
improvements and disturbance of aquatic systems at monitored sites have 
resulted in increases in toad captures and reproduction (Hobbs 2009, 
pp. 2-4; Saving Toads thru Off-Road Racing, Ranching, and Mining in 
Oasis Valley (STORM-OV) 2009b, p. 1).

[[Page 42042]]

[GRAPHIC] [TIFF OMITTED] TP20JY10.020

    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. Metapopulations can be 
expected to have local extirpations in some patches, resulting in the 
existence of empty but suitable habitat that subsequently may be 
recolonized in the future (Simandle 2006, p. 8). Events such as floods 
may simultaneously destroy existing occupied habitat, create new 
suitable habitat, and facilitate infrequent movement among different 
sites. Habitat conditions and the number of toads that occur at 
specific sites and metapopulations change from year to year, thus 
requiring site-specific management strategies.
Population Groups
    The 11 monitored sites occupied by the Amargosa toad occur in three 
groups: Harlan-Keal, Amargosa River, and Spicer/Mullin/Torrance; and 
Angel's, a single site outside the three groups. The sites associated 
with each group are discussed below.

Harlan-Keal Group

    The Harlan-Keal Group consists of four sites: 5 ac (2 ha) of 
private land (Harlan-Keal), including an irrigated garden area and 200-
square foot (ft\2\) (18.6-square meter (m\2\)) pond; a spring and 
associated pond (Crystal Spring); and two seeps named Trespass and Wild 
Burro. Crystal Spring and the two seeps occur on lands administered by 
the BLM.
    The Harlan-Keal pond was restored in 2003-2004, and has early 
successional habitat where toad reproduction occurs and may serve as a 
source population. The 2009 population estimate for the Harlan-Keal 
Group was 156, which was 22 percent below the 12-year average for this 
group of sites (Hobbs 2009, p. 2). Because of its elevation, ambient 
air temperatures at this site are always cooler than at other sites. 
This will likely affect the number of toads captured during surveys.
    The Crystal Spring site consists of a spring, pond, and outflow on 
BLM land. In 1995, a wild burro exclosure was constructed around 
Crystal Spring to reduce trampling and overuse of the spring. This 
caused an increase in emergent vegetation that has reduced the extent 
of open water, which in turn resulted in few toads remaining at the 
site. Historically, this site was maintained by ranchers and other 
private efforts which removed sediment and excess vegetation that 
maintained open water in the pond. Planning is under way to 
rehabilitate this site in 2010 to benefit Amargosa toads (STORM-OV 
2009a, pp. 1-3).
    Trespass Seep is a low-flow spring site without any substantial 
ponded area that has never supported many toads. During surveys, the 
highest number of toads captured at Trespass Seep was 12 in 1998. In 
August 2009, improvements were made to Trespass Seep by a private 
landowner that resulted in a substantial increase in ponded surface 
water and toad habitat. Within a few weeks after improvements to the 
seep, Amargosa tadpoles were observed at the site (STORM-OV 2009b, p. 
1).
    Wild Burro seep consists of a low-flow spring, an excavation with 
groundwater exposed, and wet meadow. In 1998, 12 ac (4.9 ha) 
surrounding the seep was fenced by BLM to exclude wild burros that 
overused the site. Currently this site provides little habitat for the 
Amargosa toad, with only a few toads documented at this site each year. 
In November 2009, STORM-OV submitted a plan to the BLM to create and 
enhance toad habitat at this site (STORM-OV, 2009c, pp. 1-6). STORM-OV 
is a local nonprofit organization representing the off-road, ranching, 
and mining interests, dedicated to Amargosa toad conservation projects.

Amargosa River Group

    The Amargosa River consists of three monitored segments 
characterized by riparian vegetation interspersed with flowing, open 
water. Amargosa toad population monitoring occurs along a 2-mi (3.2-km) 
section of the Amargosa

[[Page 42043]]

River that is mostly perennial, from just north of the Stagecoach 
Casino and Hotel to the Narrows, south of Beatty, Nevada (see 
distribution map available at http://www.fws.gov/nevada/nv_species/amargosa_toad.html). Land ownership is a mosaic of private, local, and 
Federal (BLM) lands. Most habitat for the Amargosa toad exists along 
this monitored section of the river, and most toads are found along the 
river corridor where perennial water occurs and bullfrogs (Lithobates 
(=Rana) catesbeiana) and crayfish (Procambarus sp.) are few or absent. 
In a typical year, tens or hundreds of thousands of Amargosa toad 
tadpoles are produced within the Amargosa River. The 2009 population 
estimate for this group was 14 percent lower than the 12-year average 
(Hobbs 2009, p. 3). This lower population estimate for the Amargosa 
River may be the result of low detectability of Amargosa toads due to 
dense vegetation, no substantial habitat improvements during the last 
few years, and predation from bullfrogs and crayfish.

Spicer/Mullin/Torrance Group

    This group consists of three privately held properties which 
include the Spicer site (320 ac; 129 ha); Mullin site (80 ac; 32 ha); 
and Torrance Ranch (130 ac; 52 ha). The Torrance Ranch was purchased by 
The Nature Conservancy (TNC) in 1999 to protect the Amargosa toad and 
to provide a site for experimental habitat management to benefit the 
Amargosa toad. All three sites are contiguous or in close proximity to 
each other, which allows movement of Amargosa toads among all three 
sites. The 2009 population estimate for this group was 86 percent above 
the 12-year average for these sites. All three property owners are 
conservation partners with the Service and NDOW, and have accomplished 
or cooperated on numerous toad habitat improvement projects.

Angel's Site

    This 296-ac (120-ha) site consists of a single location on private 
property. A spring-fed, cement lined pond that has an outflow to a 
wetland pasture provides breeding and oviposition habitat for the 
Amargosa toad. No habitat changes have been observed in at this site 
since monitoring efforts began in the mid-1990s. The pond was dry in 
2007 and no evidence of reproduction was observed in 2008. The 
population estimate for this site declined 33 percent in 2009 compared 
to 2008, and 23 percent below the 12-year average for this site (Hobbs 
2009, p. 5). Crayfish and bullfrogs occur at this site.

Other Sites

    A 2.6 mi (4.2 km) stretch of the Amargosa River north of the 
Stagecoach Hotel and Casino, has intermittent and perennial flow in 
sections, mostly associated with spring outflow. Land ownership is a 
mosaic of private and BLM lands. Cursory surveys conducted in this area 
by NDOW biologists have detected Amargosa toads. Several private 
properties are known to have suitable Amargosa toad habitat. Surveys 
have not been conducted on these properties; however, anecdotal 
observations of toads have been reported (Maciolek 1983a, pp. 9-10; 
1983b, pp. 4, A1-4). In 1993 and 1994, Heinrich (1995, p. 8) documented 
toads at eight sites, including the Manley property (spring and 
outflow), Parker Ranch (Ute Spring), and LaFleur Spring site (Roberts 
Field). No population size estimates or trends have been made for these 
other sites. Amargosa toads at these sites are not included in the 
rangewide population estimates.
    LaFleur Spring is a historic site for Amargosa toads near the 
northern range limit of the species. Altig (1987, p. 277) found up to 
74 toads at this site during 5 visits to the site in 1981. Altig 
further concluded that the toad population at the LaFleur site is 
small, with no recruitment observed in 1980 or 1981. No surveys have 
been conducted at this site since the 1980s. The Springdale site 
provides approximately 1 ac of (2.5 ha) toad habitat; toads were 
reported to be present in July and August 1983 by Maciolek (1983a, p. 
8). Habitat improvements have occurred, including the removal of salt 
cedar. The Springdale site is not included in the population monitoring 
program for Amargosa toads.
    Parker Ranch (24 ac; 212 ha) was purchased by TNC in December 2000, 
with assistance from the State of Nevada, the National Fish and 
Wildlife Foundation, and the U.S. Department of Agriculture, Natural 
Resource Conservation Service (NRCS), to protect and restore unique 
biological resources, including Amargosa toad habitat. Parker Ranch is 
approximately 4 mi (6.4 km) north of Beatty and includes Ute Spring. 
Parker Ranch is currently being grazed by 74 cattle by a local rancher 
to reduce the amount of emergent wetland vegetation to increase open 
water areas (Moore 2010, p. 3). The spring source was fenced off and 
outflow stream channels were reconstructed in recent years to prevent 
damage to stream banks (Moore 2010, p. 3). The NRCS is monitoring the 
vegetation condition to determine when cattle should be moved to other 
properties in Oasis Valley. The newly constructed stream channel and 
toad pond system has been dry for almost 2 years due to insufficient 
water and overgrowth of emergent wetland vegetation near the spring. 
Amargosa toads continue to breed in the fenced-off spring and outflow 
channel on the 6-ac (2.5-ha) private inholding. No population estimates 
are available for this area.
    The Indian Springs Complex consists of Upper, Middle, and Lower 
Indian Springs. Lower Indian Spring consists of two springs, Lower 
Indian and Cave Springs. Upper Indian Spring is the location of a 
municipal well that provides water to the town of Beatty. Middle Indian 
Spring is mostly dry, with several mature cottonwood trees. Little if 
any toad habitat currently occurs at either Upper or Middle Indian 
Springs. At Lower Indian Spring, an approximate 10-ac (4-ha) wild 
burro/livestock exclosure that surrounds two springs was constructed by 
the BLM in 1994, along with a water pipe and trough outside the 
exclosure to provide water to burros, livestock, and wildlife. 
Currently, this site is nearly dry, with no water exiting the 
exclosure. Toads have been captured at Lower Indian Spring as recently 
as 1996. No population estimates are available for this area. Attempts 
to restore toad habitat at this site in 1998 were unsuccessful, but new 
techniques have been developed, and the ATWG proposed habitat 
rehabilitation in 2010.
    Other private lands have been or could be occupied by Amargosa 
toads. Revert Spring (303 ac; 123 ha) is privately owned by the owner 
of the Stagecoach Hotel and Casino. Revert Spring is an important water 
source for Amargosa toad habitat in the river. Although Maciolek 
(1983a, p. 10) documented Amargosa toads at Revert Spring in July and 
August 1983, the current status of toads at the Revert Spring site is 
unknown. Coffer Ranch (900 ac; 364 ha) occurs at the northernmost edge 
of the range of the Amargosa toad and is owned and managed by a cattle 
company. Maciolek (1983b, p. A-1) reported that Amargosa toads were 
present at the Coffer Ranch, and suitable Amargosa toad habitat was 
present. However, no population estimates are available for these or 
other privately owned lands where Amargosa toads may occur.

Amargosa Toad Working Group (ATWG) and Amargosa Toad Conservation 
Agreement and Strategy (CAS)

    In 1996, the ATWG was organized to provide recommendations for

[[Page 42044]]

management and conservation of the Amargosa toad. The ATWG consists of 
representatives of the Service, NDOW, TNC, Nevada Department of 
Conservation and Natural Resources, Bureau of Land Management (BLM), 
Nye County, Beatty Town Board, Beatty Habitat Committee, The Amargosa 
Conservancy, private landowners in the Beatty community, the University 
of Nevada at Reno, and others. The ATWG meets semiannually to present 
and exchange information on the toad and its habitat, including the 
status of habitat conditions and ongoing habitat projects, potential 
threats to the toad, and population monitoring data, and to identify 
new conservation tasks.
    In 2000, the ATWG completed the Amargosa Toad CAS (NDOW 2000, pp. 
1-12), which provides management and conservation guidance for the 
Amargosa toad. The CAS informs management of the conservation needs of 
the toad, prioritizes tasks, and provides an implementation schedule. 
The ATWG is currently updating the CAS to include accomplishments and 
updated conservation needs for the toad.
    The CAS was developed to expedite toad conservation over a period 
of 10 years by providing guidance and a framework for implementation of 
cooperative long-term conservation actions to benefit the toad and co-
occurring species. Signatories to the CAS include NDOW, Nye County 
Department of Natural Resources, the Service, BLM, TNC, the Nevada 
Natural Heritage Program, and the University of Nevada at Reno. The 
signatories provide representatives to the ATWG. The signatories and 
ATWG are committed to implementing specific conservation actions 
(tasks) which identify, reduce, or eliminate threats to the species, 
and maintain and enhance a properly functioning ecosystem for the 
Amargosa toad and other indigenous species of Oasis Valley. The ATWG 
meets semiannually to plan Amargosa toad conservation actions. Most 
conservation actions in the CAS are implemented by local private land 
owners, and land and resource managers.
    Many of the conservation actions implemented by the ATWG and its 
various partners are a direct result of the commitments made in the CAS 
for the Amargosa toad (NDOW 2000, pp. 1-12). The goals of the CAS are 
to manage threats, maintain habitats, monitor populations, and test and 
evaluate habitat manipulations. Completed conservation actions 
identified in the CAS have addressed threats identified in Factors A, 
B, C, and E (see below). We consider the CAS successful if considerable 
progress is made towards achieving these goals. CAS accomplishments 
that have contributed towards success include 12 years of population 
monitoring and maintaining population data in a database; salt cedar 
removal; habitat rehabilitation and enhancement; research; public 
education and outreach; and habitat acquisition as discussed in Factor 
A. Other CAS accomplishments include control of predators through 
habitat manipulation and work with the local community to achieve 
conservation such as an open space plan. The CAS signatories and the 
ATWG, in cooperation with local landowners, have planned and initiated 
multiple projects to protect, restore, and enhance toad habitat, and 
create new habitat. Overall success is measured by population 
monitoring data that show that rangewide, Amargosa toad populations are 
relatively stable and respond promptly and positively to habitat 
improvements. Previous habitat improvements on the Amargosa River, 
Harlan-Keal, Mullin, and Spicer sites have all resulted in substantial 
population increases of toads. In 2005, vegetation was removed by NDOT 
at the U.S. 95 Highway bridge over the Amargosa River in Beatty. This 
resulted in a positive response by toads as shown by a large 
reproductive event and a 2006 population estimate of 1,854 for the 
river which was the highest on record (ATWG 2005, p. 2; Wixson 2006, p. 
3). Again in 2005, vegetation was cleared from the pond at the Harlan-
Keal site with funding from the Service and NDOW which resulted in an 
estimated 90 percent increase in the population in 2006 over the 2005 
estimate (Wixson 2006, p. 2).
    The ATWG is in the process of updating the CAS and anticipates a 
revised CAS by the end of 2010. The revised CAS will acknowledge 
accomplishments and identify the conservation needs of the toad for the 
next 10 years. The revised CAS will operate in a similar manner as the 
existing one. The CAS has proven, based on its 10 year track record, to 
be an effective tool in furthering the long-term conservation of the 
species.

Summary of Information Pertaining to the Five Factors

    Section 4 of the Act (16 U.S.C. 1533) and implementing regulations 
(50 CFR part 424) set forth procedures for adding species to the 
Federal Lists of Endangered and Threatened Wildlife and Plants. Under 
section 4(a)(1) of the Act, a species may be determined to be 
endangered or threatened based on any of the following five factors:
    (1) The present or threatened destruction, modification, or 
curtailment of its habitat or range; (2) overutilization for 
commercial, recreational, scientific, or educational purposes; (3) 
disease or predation; (4) the inadequacy of existing regulatory 
mechanisms; or (5) other natural or manmade factors affecting its 
continued existence. In making this finding, information pertaining to 
the Amargosa toad in relation to the five factors provided in section 
4(a)(1) of the Act is discussed below.
    In making our 12-month finding on a petition to list the Amargosa 
toad, we considered and evaluated the best available scientific and 
commercial information. The analysis of potential threats to the 
Amargosa toad discussed below includes those identified in the petition 
and those that we considered to be substantial in our 90-day finding 
(74 FR 46551).

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

Private Land Development
    The petition identified several potential residential or commercial 
developments on private land that could adversely affect the Amargosa 
toad or its habitat. However, based on information provided by TNC 
during our review (Moore 2010, pp. 1-3), none of the proposed 
developments appear to be viable. Real estate and development markets 
in nearby Pahrump and Las Vegas influence markets in the Beatty area, 
and each of these three areas have experienced a downturn in both the 
general economy and the housing market. Plans for a shooting range 
across from Torrance Ranch have been abandoned and the property was 
recently sold to an individual who plans to build a home on the 40-ac 
(16-ha) site (Moore 2010, p. 3). A geothermal project at a hot spring 
on private lands identified by CBD as a threat (2009, p. 2) has been 
abandoned (Moore 2010, pp. 1-3). Although development may occur within 
the range of the Amargosa toad over the near term, it is difficult to 
predict the scope of that development based on the available 
information. Furthermore, humans and Amargosa toads have coexisted in 
the Beatty area since the early 1900s. Amargosa toads at the Harlan-
Keal site and other sites where residential or commercial development 
and toads co-occur demonstrate that toad and human interface can be 
compatible. Toads occur in most disturbed and developed areas with 
surface water and may be locally abundant. During our review, we

[[Page 42045]]

found no indication that the economic growth of Beatty will change 
substantially in the foreseeable future. Due to the absence of 
potential developments identified in the petition and the ability of 
toads to coexist with humans in developed and disturbed areas, we 
conclude habitat loss as a result of development on private land is not 
a substantial threat to the Amargosa toad now or in the foreseeable 
future.
    Groundwater Development and Extraction
    The petitioners provided information that claimed existing and 
future water uses and developments are important threats that reduce 
surface water available for Amargosa toads in Oasis Valley and that 
result in habitat loss. The majority of water right allocations within 
the basin are spring diversions for irrigation and livestock watering. 
Priority dates for groundwater rights, including those of Beatty Water 
and Sanitation District (BWSD), range from the 1920s to 1996, with the 
majority dating to the late 1980s or earlier. The priority dates are 
the dates the application are submitted and determine the seniority of 
the water right relative to other water rights in the affected basin. 
Spring diversions are located primarily along or near the Amargosa 
River channel. Groundwater rights are limited to approximately one 
sixth of water right allocations in the valley (by volume), 85 percent 
of which are held by the BWSD as a source of supply for homes and 
businesses in the town of Beatty. The BWSD holds water rights for three 
wells in the town of Beatty and two wells several miles northwest of 
town (including one at Indian Springs), in addition to a groundwater 
right at the Barrick Mine in Amargosa Valley (Nevada Division of Water 
Resources, http://water.nv.gov/). Other groundwater rights in Oasis 
Valley (a total of 8) are for irrigation, recreation, livestock 
watering, and minor commercial and mining activities, most in the 
amount of 20 acre-feet per year (afy) or less.
    Currently, TNC is negotiating purchase of the water rights (500 
afy) at Revert Spring with the owner of the Stagecoach Hotel and Casino 
to establish long-term protection measures for the water flowing from 
the spring source into the Amargosa River. Acquisition of this 
important water source can reduce the threat of its use for commercial 
purposes and enable TNC to meet its commitment in the CAS to work with 
private landowners to pursue conservation actions such as acquisitions 
and easements (NDOW 2000, p. A-20). However, we recognize that this 
transaction has yet to be completed, and cannot be certain that these 
rights will be secured.
    Groundwater level records for Oasis Valley, which are both recent 
and long enough to assess trends (e.g., over the last 10 years or 
more), are limited to monthly and bimonthly measurements collected by 
the U.S. Geological Survey (USGS) for the U.S. Department of Energy 
(USDOE) as part of the USDOE Environmental Restoration Program (USGS/
U.S. DOE Cooperative Studies in Nevada, http://nevada.usgs.gov/doe_nv/
). Specifically, groundwater level measurements are available for seven 
wells or nested wells along or near the Amargosa River channel in Oasis 
Valley and a number of additional wells to the north and east within 
the valley and up gradient basins for the period 1998 to late 2009. The 
wells range in depth from 200 ft (61 m) or less in consolidated 
sedimentary deposits to thousands of feet in the volcanic rock aquifer. 
Trends in groundwater levels along the Amargosa River channel from 1998 
to 2009 are mixed, some increasing moderately, some decreasing 
moderately, and some relatively constant on an annual basis. Water 
levels in two of the seven monitoring wells located along or near the 
Amargosa River channel (well ER-OV-03 and the Beatty Wash Terrace Well) 
decreased 1.3 to 1.5 ft (0.4 to 0.5 m) from 2000 to late 2009. However, 
these declines occurred in no clear relation to permitted or 
certificated groundwater rights (pumping at permitted supply wells). 
Rather, they may be indicative of local evapotranspiration responses. 
Elsewhere along the river channel, groundwater levels were unchanged, 
or increased a few tenths of a foot from 2000 to late 2009 (ER-OV04a, 
Springdale Upper Well, ER-OV-02, ER-OV-05, and ER-OV-06a).
    In areas to the north and east which supply groundwater to the 
vicinity of the Amargosa River channel and Amargosa toad habitat in 
Oasis Valley, specifically northeastern Oasis Valley and the area of 
Pahute Mesa (the latter located in the Gold Flat and Forty mile Canyon-
Buckboard Mesa basins) (Laczniak et al. 1996, pp. 18-19; Reiner et al. 
2002, pp. 8-9; Fenelon et al. 2010, pp. 22-23 and Plate 5), water 
levels in USDOE Environment Restoration Program wells increased a few 
tenths of a foot to approximately 1.5 ft over this same period.
    No groundwater level data are available for the vicinity of the 
BWSD supply wells. As such, the effects of BWSD pumping on surface 
water resources cannot be evaluated at this time except as they may be 
judged from the results of biannual Amargosa toad surveys. This 
suggests that any reduction in population is limited to the area of 
Indian Springs. BWSD pumping at the Indian Springs well has decreased 
since the late 1990s, but Indian Springs remains one of three primary 
supply wells in Oasis Valley for the town of Beatty. With respect to 
the potential for additional groundwater pumping in Oasis Valley, 
actual groundwater withdrawals by the BWSD have been limited to 
approximately 10 to 15 percent of their existing rights over most of 
the last decade (Eng 2010, p. 1). Whereas substantially more 
groundwater could be pumped for municipal purposes under existing BWSD 
rights, their pumping within Oasis Valley has been fairly constant. 
Overall demand has decreased approximately 25 percent (coupled with a 
decrease in pumping at the Barrick Mine) over this same period of time 
based on pumping inventories provided by the Nevada State Engineer 
(NSE). Additionally, BWSD demand varies seasonally, with demand at a 
minimum from December through March, the latter of which coincides with 
the beginning of the Amargosa toad breeding season. Moreover, the NSE 
has ruled that the degree of hydraulic connection between groundwater 
and surface water in Oasis Valley is such that they constitute a single 
source (NSE Ruling 4669, 1998) and that no unappropriated water existed 
in the basin as of 1995 (NSE Ruling 4174, 1995), making additional 
allocations, groundwater or surface water, unlikely.
    Excessive groundwater withdrawals have the potential to affect 
springs and rivers that depend on groundwater for recharge or base 
flows. Field reconnaissance and Nevada Division of Water Resources well 
drilling records identified approximately 15 springs and 20 
nonmunicipal wells that supply water to individual homes and ranches in 
Oasis Valley (Reiner et al. 2002, p. 33). A reasonable estimate of 
groundwater withdrawal consumed from each of these sources is 1 afy 
(Reiner et al. 2002, p. 33). Based on this consumption rate and the 
number of supply sources, a reasonable estimate of the nonmunicipal use 
of groundwater from Oasis Valley is 35 afy. Estimates of the total 
annual groundwater withdrawal from Oasis Valley, computed by combining 
municipal and non-municipal estimates, declined from 440 afy in 1996, 
when Beatty's human population was 2,068, which was the highest during 
the period 1991-2007 (Stantec 2009, p. 22), to 210 afy in 1999, when 
Beatty's population declined to 1,703.

[[Page 42046]]

    The population estimates for Beatty in 2007 indicate a resident 
base of approximately 1,068 persons (Stantec Consulting 2009, p. 22). 
This estimate reflects a declining population trend during the period 
1991-2007. While the future population size of Beatty is unknown, we 
found no indication that the human population will increase beyond 
historic levels and we do not anticipate an increase in use of 
groundwater to support new residential development. We conclude that 
future human population effects on the Amargosa toad are driven by the 
economic status and growth of the Beatty. Since there is no indication 
that growth will increase, we conclude that demand for groundwater is 
not likely to rise.
    The petitioners submitted comments that identified a proposed solar 
energy project in Amargosa Valley requiring 3,000 afy of groundwater 
for wet-cooling and operation (CBD 2009, pp. 1-2). This energy project 
remains proposed but has been modified to use dry-cooling that would 
reduce groundwater use to 400 afy. The 400 afy of groundwater proposed 
for the project is currently used for agriculture and, therefore this 
level of groundwater use is not anticipated to significantly affect 
existing groundwater levels in the up gradient areas where Amargosa 
toads occur (Peterson 2010, p. 1).
    The petitioners also identified 11 Department of Energy (DOE) 
applications for water rights in Oasis Valley as a potential threat to 
the toad through groundwater withdrawal effects (CBD 2009, p. 2). The 
DOE applications were submitted for construction of a railroad to a 
proposed nuclear waste repository and were protested by the petitioners 
and others. The Service recommended that DOE transport water needed for 
this project from sources other than those associated with the Amargosa 
toad, Ash Meadows, and Devils Hole. In February 2010, DOE withdrew 
their applications for water rights in the Oasis Valley.
    Based on the available information on volume, timing, and location 
of groundwater withdrawals, historic use of groundwater, and water-
level measurements, we conclude that water use and development in Oasis 
Valley is not a substantial threat to the Amargosa toad at this time or 
in the foreseeable future. No declines in groundwater or toad numbers 
have been observed at monitored sites as a result of pumping. The 
current and foreseeable demand for groundwater in Oasis Valley remains 
consistent with historical uses.
    Inadequate Habitat Enhancement Planning and Implementation
    The petitioners state that BLM failed to initiate planning for 
habitat enhancement projects including Wild Burro Seep and Upper Cave 
Spring in the Lower Indian Spring system (CBD 2009, p. 20). In fall 
2009, STORM-OV, in cooperation with BLM and the ATWG, modified Wild 
Burro Seep and greatly increased the extent of surface water and toad 
habitat at the site. STORM-OV and BLM developed plans to restore Lower 
Indian Springs and Crystal Spring in 2010 and 2011 (STORM-OV 2009a, pp. 
1-3; Spicer 2009, pp. 1-5). Habitat enhancement is a conservation 
action in the CAS (NDOW 2000, p. A-11).
    The Stagecoach Hotel and Casino owner is a conservation partner 
with TNC and the Service. In 2001, the Service's Partners for Fish and 
Wildlife Program funded habitat improvements in the vicinity of the 
Stagecoach to benefit the Amargosa toad. The owner and TNC continue to 
improve habitat along the river behind the property, which is part of a 
parcel identified as a fee-title donation to TNC for conservation 
purposes pursuant to prescribed conservation actions in the CAS. In 
addition, TNC and the Nevada Department of Transportation (NDOT) are 
working to remove debris from the riverbank, which should improve 
habitat for the Amargosa toad.
    In 2007, 30 ac (12 ha) of nonnative trees were removed from the 
Mullin site and replaced with native willows and cottonwoods as 
prescribed in the CAS (NDOW 2000, p. A-11). During the 2009 survey, 137 
Amargosa toads larger than 2 in (50 mm) were captured on the Mullin 
site. This was the highest number of captures for this site (Hobbs 
2009, p. 4).
    Three springs on the Spicer site have been enhanced for the 
Amargosa toad by the landowner. Surface water is distributed on the 
Spicer site through a system of pipes which provides most of the water 
for toad habitat. Manipulation of the distribution pipes provides a 
habitat management tool to allow ponds to be created, or dried to 
remove crayfish and bullfrogs as prescribed in the CAS (NDOW 2000, pp. 
A-11 and A-12). Amargosa toads responded positively to the habitat 
improvements in 2009, increasing by 300 percent of captured and marked 
toads since 2008 (Hobbs 2009, p. 4).
    The Amargosa River Planning Team was formed in October 2009 as a 
result of a recommendation by the ATWG that was included in the CAS 
(NDOW 2000, p. A-14). The team consists of ATWG representatives 
including the Service, NDOW, Nye County, BLM, and TNC, but also local 
landowners. The purpose of the team is to monitor habitat conditions of 
the river, develop management recommendations, and coordinate habitat 
improvement with landowners and managers on behalf of the signatories 
of the CAS and the ATWG.
    The overall habitat suitability of individual sites varies from 
year to year depending on conditions and may become unsuitable for 
toads. Because the Amargosa toad occurs as metapopulations, toads will 
move back into these sites from neighboring sites once the habitat 
becomes more suitable. In the absence of natural disturbance such as 
flood events and wildfires, toad habitat will likely require periodic 
manipulation or other forms of disturbance such as burro or cattle use 
to sustain toad populations. Based on the metapopulation structure of 
the toad, successful habitat projects and disturbance by burros and 
cattle, we anticipate that habitat planning and implementation have 
resulted in positive responses by toads. We expect the Amargosa River 
Planning Team, TNC, BLM, Service, and private landowners to continue 
their efforts to maintain and improve toad habitat into the foreseeable 
future in accordance with the CAS. We expect members of the ATWG and 
private landowners to continue their current efforts to maintain and 
improve toad habitat, as they have in the past, in accordance with the 
CAS into the future. As a result, we have determined that habitat 
planning and implementation is not a threat to the Amargosa toad now, 
nor is it expected to be so in the foreseeable future.
Vegetation Overgrowth
    Overgrowth of vegetation in aquatic habitats is an ongoing 
management objective for the Amargosa toad as specified in the CAS 
(NDOW 2000, pp. A-11 and A-16). Habitat for Amargosa toads at several 
spring sites including Torrance Ranch, Lower Indian Spring, and Crystal 
Spring, has degraded as a result of overgrowth of emergent vegetation 
and loss of open water. Overgrowth of vegetation occurs mostly at small 
spring sites and in the absence of disturbance or management. Although 
Lower Indian Spring and Crystal Spring are small spring sites and 
represent only a small fraction of the species' individuals and 
distribution, the ATWG considers vegetation management a priority for 
these sites. Mechanical removal, controlled burns, and grazing are 
proven tools to manage vegetation in spring systems at Harlan-Keal 
(ATWG 2004, p. 3) and Torrance Ranch (ATWG 2007, attachment 1, p. 1).

[[Page 42047]]

Spring-supplied ponds typically require disturbance or periodic removal 
of vegetation to maintain suitable habitat conditions (e.g., open 
water) for the Amargosa toad. Local ranchers historically managed 
Crystal Spring and other springs to maintain open water (Spicer 2010, 
p. 1). Limited use by livestock or feral burros provides disturbance 
that benefits toads; however, excessive use by livestock or feral 
burros result in degradation of habitat. Current and future habitat 
projects at spring sites are designed to minimize vegetation growth, 
compensate for potential reductions in spring flow due to overgrowth of 
vegetation, and maintain proper habitat conditions for the toad. 
Currently, excess vegetation conditions occur at Crystal and Lower 
Indian Springs, but habitat modification proposed for 2010 and 2011 at 
these sites (STORM-OV 2009a, pp. 1-3; Spicer 2009, pp. 1-5) is 
anticipated to substantially improve habitat conditions for the toad. 
As stated previously, we expect the efforts to maintain and improve 
toad habitat which includes control of vegetation to continue in 
accordance with the CAS. Therefore vegetation overgrowth is not a 
significant threat to the Amargosa toad now, nor is it expected to be 
so into the foreseeable future.
Grazing and Trampling
    The petitioners state that use of springs by feral burros and 
cattle may result in degraded habitat and reduced numbers of Amargosa 
toads (CBD and PEER 2008, pp. 17-18, 21 and 23-25). The current level 
of burro occurrence in Amargosa toad habitat varies by site and ranges 
from zero to moderate with most use along the Amargosa River. Cattle 
use of Amargosa toad habitat is limited to the northern sites where a 
cattle operation is located (Coffer Ranch) and sites targeted for 
vegetation reduction. While burros and livestock (ungulates) may 
trample Amargosa toad eggs and larvae, light to moderate disturbance is 
important to the Amargosa toad which is a disturbance-dependant species 
(ATWG 2005, p. 2). In the absence of disturbance, vegetation grows 
uncontrolled and reduces open areas necessary for the toads. Intensive 
and uncontrolled use of Amargosa toad habitat by ungulates may threaten 
the species by degrading habitat and killing individual toads; however, 
light to moderate use is known to be beneficial to the Amargosa toad. 
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. Fencing installed at the Crystal and Indian spring sites 
to exclude feral burros most likely has contributed to declines in toad 
populations at these sites by reducing habitat disturbance. BLM manages 
the burro population and conducts burro ``gathers'' when the burro 
numbers exceed the appropriate management level for the area in 
accordance with the CAS (NDOW 2000, p. A-16). Most feral burro use of 
monitored sites occurs along the river. We conclude that light to 
moderate ungulate use is not a substantial threat to the toad and 
likely provides some benefit to the Amargosa toad. Although the number 
of feral burros fluctuates, we do not anticipate the level of burro use 
in Amargosa toad habitat to increase so that it would affect toad 
populations in the foreseeable future.
Recreation and Off-Highway Vehicle (OHV) Activity
    OHV activity affects Amargosa toads most during the breeding season 
and during the especially vulnerable egg and tadpole stages of 
development. OHV effects are only known to be a concern along the 
Amargosa River near the Stagecoach Hotel and Casino. TNC biologists 
have observed small isolated pools containing egg strands or tadpoles 
in various stages of development that were affected by OHVs in the 
riverbed within the Town of Beatty. The local nonprofit group, STORM-
OV, is attempting to educate the OHV users about the need to avoid 
ponded water during the toad breeding season, a conservation action 
prescribed in the CAS (NDOW 2000, p. A-18). In addition, TNC plans to 
use its river properties behind the Stagecoach Hotel and Casino and 
northward in educational opportunities. These two groups propose to 
conduct town meetings to inform Beatty residents of the need to avoid 
damaging toad breeding pools during the defined breeding season. While 
localized OHV use may cause a relatively small number of eggs or 
tadpoles to be removed from the affected population, this level of loss 
is not substantial in the context of the potentially tens or hundreds 
of thousands of Amargosa toad eggs and tadpoles produced in a typical 
year.
    No landowners or managers have identified, nor are we aware of any 
spring sites that are substantially affected by OHV activity. The 
petitioners identified an OHV race that passes near Crystal Spring as a 
potential threat to the toad. In 2008, BLM chose an alternate route 
away from toad habitat for OHV events near Crystal Spring and continues 
to consider the toad during OHV permitting actions. Due to the absence 
of substantial effects resulting from recreation or OHV use in toad 
habitat and the location of many of the spring sites on private land 
that have no OHV use, we do not expect effects from recreation and OHV 
use to increase or become a threat to the toad in the foreseeable 
future.
Invasive Plant Species
    The petitioners assert 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).
    Salt cedar is an exotic, invasive species that grows in shrub form 
to medium tree size and is native to Eurasia. Removal of salt cedar is 
identified as a conservation action in the CAS (NDOW 2000, p. A-11). 
Native aquatic and wetland herpetofauna may be negatively impacted in 
areas where salt cedar draws down surface water (Shafroth et al. 2005, 
pp. 237-238). Water-use studies indicate that increases in water yield 
following salt cedar control are likely to occur only when a salt cedar 
stand containing high leaf area is replaced by vegetation with a lower 
leaf area (Shafroth et al. 2005, pp. 237-238). The native vegetation in 
Oasis Valley requires more water than is provided by local rainfall. As 
a result of high evapotranspiration rates during the summer, these 
plants must rely on local groundwater for sustenance (Reiner et al. 
2002, p. 42). Anderson et al. (2004, cited in Shafroth et al. 2005, pp. 
237-238) present data from the lower Colorado River suggesting that 
abundances of several of the most common insect families in riparian 
areas occur in comparable or greater abundance on salt cedar than on 
most native vegetation. Efforts to remove salt cedar and other 
nonnative, invasive plants from the Amargosa River watershed have 
occurred since 2003. Replacing salt cedar with native vegetation may 
result in lower evapotranspiration rates. Eleven grants provided 
$118,500 for salt cedar removal from 11 private properties and BLM, 
NDOT, and BWSD-managed land. Salt cedar has been removed from 
approximately 1,895 ac (767 ha) of Amargosa toad habitat, and salt 
cedar removal efforts will likely continue. Amargosa toad population 
monitoring data may be used to assess and measure the effect of salt 
cedar removal on the toad. We do not believe salt cedar is a 
significant threat to the Amargosa toad now or in the foreseeable 
future because salt cedar has been removed from toad habitat and those 
efforts continue in accordance with the CAS.

[[Page 42048]]

Failure of the CAS to Protect Toads and Habitat
    The petitioners claim that the CAS failed to protect Amargosa toads 
and increase toad populations. The CAS is a voluntary, non-regulatory 
agreement. The CAS was developed to expedite Amargosa toad conservation 
over a period of 10 years by providing guidance and a framework for 
implementation of cooperative long-term conservation actions to benefit 
the toad and co-occurring species. Signatories to the CAS include NDOW, 
Nye County Department of Natural Resources, the Service, BLM, TNC, the 
Nevada Natural Heritage Program, and the University of Nevada at Reno. 
The signatories provide representatives to the ATWG. The signatories 
and ATWG are committed to implementing specific conservation actions 
(tasks) which identify, reduce, or eliminate threats to the species, 
and maintain and enhance a properly functioning ecosystem for the 
Amargosa toad and other indigenous species of Oasis Valley. The ATWG 
meets semi-annually to assess the conservation needs of the toad and 
plan Amargosa toad conservation actions. Most conservation actions in 
the CAS are implemented by local private land owners, and land and 
resource managers.
    Many of the conservation actions implemented by the ATWG and its 
various partners are a direct result of the commitments made in the CAS 
for the Amargosa toad (NDOW 2000, pp. 1-12). The goals of the CAS are 
to manage threats, maintain habitats, monitor populations, and test and 
evaluate habitat manipulations. Completed conservation actions in the 
CAS have addressed threats identified in Factors A, C, and E. We 
consider the CAS successful as considerable progress has been made 
towards achieving these goals. The CAS accomplishments that have 
contributed towards success include 12 years of population monitoring 
and maintaining population data in a database; burro management through 
monitoring and gathers; salt cedar removal; habitat rehabilitation and 
enhancement; research; public education and outreach; and habitat 
acquisition as discussed above in this factor. Other CAS 
accomplishments include control of predators through habitat 
manipulation and work with the local community to achieve conservation 
such as an open space plan. The CAS signatories and the ATWG in 
cooperation with local landowners have planned and initiated multiple 
projects to protect, restore, and enhance toad habitat, and create new 
habitat. Overall success is measured by population monitoring data that 
show that rangewide, Amargosa toad populations are relatively stable 
and respond promptly and positively to habitat improvements. Previous 
habitat improvements on the Amargosa River, Harlan-Keal, Mullin, and 
Spicer sites have all resulted in substantial population increases of 
toads. In 2005, vegetation was removed by NDOT at the U.S. 95 Highway 
bridge over the Amargosa River in Beatty. This resulted in a positive 
response by Amargosa toads as shown by a large reproductive event and a 
2006 population estimate of 1,854 for the river which was the highest 
on record (ATWG 2005, p. 2; Wixson 2006, p. 3). In 2005, vegetation was 
cleared from the pond at the Harlan-Keal site with funding from the 
Service and NDOW which resulted in an estimated 90 percent increase in 
the population in 2006 over the 2005 estimate (Wixson 2006, p. 2).
    The ATWG is in the process of updating the CAS and the group 
anticipates a revised CAS by the end of 2010. The revised CAS will 
acknowledge accomplishments and identify the conservation needs of the 
Amargosa toad for the next 10 years. The existing CAS and revision will 
function similarly. Although the CAS is a voluntary, non-regulatory 
agreement, we conclude that the CAS efforts have been very successful 
in establishing a coalition of partners, including State and Federal 
agencies, local government, private landowners, and conservation 
organizations committed to reduce or eliminate the threats to the 
species and assure long-term conservation for the Amargosa toad. In the 
absence of the CAS, conservation progress would proceed at a reduced 
rate but would not result in the species becoming threatened. 
Therefore, based on implementation of various conservation actions 
resulting from the CAS as discussed in the factor above, we find that 
the existence and implementation of the CAS do not pose a threat to the 
species.
Summary of Factor A
    Development on private lands and use of groundwater are not 
significant threats to the Amargosa toad. Most previously proposed 
developments have been abandoned. With potential development stalled, 
growth activity within Beatty is not expected to change substantially 
in the foreseeable future. Groundwater use in the Beatty area has 
decreased or remained constant, and groundwater levels have fluctuated 
but these fluctuations do not appear to affect Amargosa toad numbers or 
distribution. Habitat has been improved at several sites and 
improvements at other sites are planned for 2010 and 2011. Although 
some sites are affected by overgrowth of vegetation, past and ongoing 
conservation and management actions have improved toad habitat and 
contributed to stable Amargosa toad populations, as reflected in the 11 
years of population monitoring. In one particular instance, a habitat 
manipulation project was developed and implemented, and was very 
successful in transforming a small seep into a new breeding site for 
toads (STORM-OV 2009a, p. 1). Amargosa toad population estimates are an 
indication of habitat quality at a given site, and in those areas where 
habitat improvements have been conducted, Amargosa toad populations 
have increased substantially. Grazing by cattle and feral burros may be 
locally excessive, but moderate use provides needed disturbance to the 
aquatic systems that improves Amargosa toad habitat. Some local areas 
are impacted by OHV use but not to the extent that population declines 
can be identified. There has been no apparent reduction in the current 
range of the Amargosa toad compared to the historical range. As a 
result of conservation efforts accomplished by TNC through habitat 
acquisition and improvements, and by various groups through other 
habitat improvement projects at Mullins, Harlan-Keal, Spicer, and 
Torrance, along the River, and at Parker Ranch and Trespass Seep, there 
has been an increase in habitat quality or quantity for the Amargosa 
toad at these sites. Additionally, private landowners have recently 
become and remain involved in conservation efforts. Salt cedar has been 
substantially removed from private and BLM land. Completed actions 
prescribed in the CAS to conserve the Amargosa toad have been shown to 
be successful in meeting the objectives in the CAS and reducing or 
eliminating the threats to the Amargosa toad under Factor A. We 
conclude that the present or threatened destruction, modification, or 
curtailment of the habitat or range of the Amargosa toad is not a 
significant threat to this species now or in the foreseeable future, 
due to the limited growth projected for Beatty, current and anticipated 
groundwater use and levels; completed and proposed habitat improvements 
including removal of salt cedar; continuing management of the Amargosa 
River and adjacent habitat under the direction of the Amargosa River 
Planning Team, a subcommittee of the ATWG; and continued implementation 
of conservation

[[Page 42049]]

measures in accordance with the revised CAS.

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

    The petitioners provided no information regarding threats under 
this factor, nor do we have information on the potential threat of 
overcollection or overutilization for commercial, recreational, 
scientific, or educational purposes. There is no information to 
indicate this factor will become a threat to the species in the 
foreseeable future. We find overutilization for commercial, 
recreational, scientific, or educational purposes does not threaten the 
Amargosa toad. Based on a review of the best available scientific and 
commercial data, we find no indication that overutilization for 
commercial, recreational, scientific, or educational purposes is a 
threat to the Amargosa toad now or in the foreseeable future.

Factor C. Disease or Predation

Disease
    Chytridiomycosis is an infectious disease of amphibians caused by 
the chytrid fungus Batrachochytrium dendrobatidis. Although the fungus 
has been detected in bullfrogs in the Oasis Valley, it has not been 
detected in Amargosa toad populations. Chytrid fungus has been 
identified in western toad (Anaxyrus boreas) populations in Colorado 
where western toad occurrence is restricted to high elevations (7,200 
to 11,150 ft [2,200 to 3,400 m]; Muth et al. 2003, p. 358). The Service 
and NDOW have no evidence that chytrid or other diseases are affecting 
or will affect the Amargosa toad population. No sign of chytrid fungus 
or other disease has been observed in the hundreds of Amargosa toads 
captured and inspected rangewide every year since 1995. Further, no ill 
or dying toads have been reported by landowners or agency biologists. 
Population monitoring data do not indicate a decline in Amargosa toad 
numbers. Therefore, we find disease is not a threat to the Amargosa 
toad now or in the foreseeable future.
Predation
    Predation of all life stages of the Amargosa toad by nonnative 
crayfish and bullfrogs is a threat to the Amargosa toad at the 
metapopulation level. However, metapopulations of a species allow for 
the coexistence of predators and prey, or coexistence of competitors. 
While local extinctions may occur, the species may persist regionally 
if the metapopulation structure ensures that predator and prey are not 
present in all occupied patches all of the time (Simandle 2006, p. 9).
    Currently, the most promising management tool for nonnative 
predators involves manipulating and enhancing habitat for Amargosa 
toads while making habitat less suitable for bullfrogs and crayfish, as 
prescribed in the CAS (NDOW 2000, p. A-12). This is accomplished by 
drawing down ponded areas that contain nonnative predators and allowing 
them to be dry for a period of time long enough to kill the nonnative 
predators and cause toads to move to nearby sites. Recently completed 
and proposed habitat projects have incorporated the capability of 
adding or removing water to allow sites to dry to remove or reduce 
numbers of bullfrogs and crayfish, and are designed to provide an 
advantage to Amargosa toads including substrate selection and water 
depth. One of the goals of the CAS is to manage threats to the Amargosa 
toad. We consider the CAS successful as considerable progress has been 
made towards achieving this goal and addressing threats to the Amargosa 
toad under Factor C.
    The life history of the toads further reduces the threat of 
nonnative predators. Under average conditions, toads produce tens or 
hundreds of thousands of eggs, larvae, and toadlets each year, most of 
which will not survive to adults with or without predatory pressure.
    Although bullfrogs are known to occur at 10 of 18 sites occupied by 
Amargosa toads, the monitoring data do not indicate a declining toad 
population trend. We have documented Amargosa toads in the stomach 
contents of bullfrogs (ATWG 2003, p. 2). While there is no coordinated 
control effort, bullfrogs are removed from the Amargosa River and other 
sites occupied by Amargosa toads during population surveys. All toad 
habitat improvement projects consider the needs of the toad and select 
against bullfrogs. Bullfrogs generally require deeper, impounded 
perennial waters, which are more limited than shallow stream and spring 
outflow habitat in Oasis Valley. Observation and removal of bullfrogs 
from stream and spring outflows can be very effective in controlling 
bullfrog numbers.
    Since their introduction in the mid-1980s, nonnative crayfish have 
become established along most of the Amargosa River and at seven spring 
sites occupied by the Amargosa toad. We have no Amargosa toad 
population data prior to the introduction of crayfish, bullfrogs, or 
other nonnative Amargosa toad predators into Oasis Valley; therefore, 
we cannot assess the potential impact of predators on the Amargosa toad 
population. However, we do have Amargosa toad survey data collected 
since 1998 for sites occupied and unoccupied by bullfrogs and crayfish. 
Population numbers at sites with predators and without predators have 
fluctuated in a similar manner, which indicates there is no population 
level of effect that can be attributed to predation. This is consistent 
with the way in which a metapopulation structure of interconnected 
populations functions; thus, in certain areas Amargosa toads may become 
extirpated, but repopulate those areas at a later time. The capability 
of toads to move among these sites in response to threats and habitat 
condition allows toads to coexist with nonnative predators. For 
instance, the population estimate for the Spicer property in 2009 
increased from 53 to 167, even though it is a site where crayfish and 
bullfrogs are abundant. The increase in Amargosa toad numbers in 2009 
at the Spicer site is most likely a result of habitat improvements, 
which demonstrates the success of habitat condition. We are unaware of 
any extirpations that can be attributed to crayfish or bullfrogs, but 
Amargosa toads have been extirpated or nearly extirpated from Lower 
Indian Spring and Crystal Spring as a result of poor habitat conditions 
mostly due to overgrowth of vegetation.
    In 2009, NDOW, TNC World Wide Office, and Arizona Game and Fish 
Department provided funding to TNC to develop crayfish removal 
strategies which included habitat characterization, crayfish 
distribution, and control techniques in a five-state effort (AZ, NM, 
CA, UT, and NV). These studies are currently under contract; the first 
phase is to be completed by June 30, 2010.
    We expect the current level of predation by crayfish and bullfrogs 
to continue into the foreseeable future, but do not consider this level 
of predation a significant threat due to the life history 
characteristics of the Amargosa toad and their ability to coexist with 
nonnative predators and move among metapopulations. This determination 
is based on the Amargosa toad metapopulation structure; habitat 
projects that select for toads; the life history of the toad; and 12 
years of toad population monitoring data that shows toads can coexist 
with nonnative predators.
Predation by Fish Species
    The majority of habitats in Oasis Valley supporting Amargosa toad 
populations are not structurally capable of supporting the large-bodied 
predatory

[[Page 42050]]

fish that would be capable of significant predation on Amargosa toads 
(NDOW 2009, p. 4). Largemouth bass (Micropterus salmoides) are known to 
occur in at least one pond on private property in Oasis Valley, but 
Amargosa toads are not a primary component of their diet. Black 
bullhead catfish (Ictalurus melas) and Amargosa toads have co-occurred 
at one pond on private land at the Harlan-Keal site for at least 10 
years; however, the pond dried during the summer 2009, and catfish are 
not expected to persist at this site. Therefore, we do not consider 
largemouth bass or catfish to be a significant threat to the Amargosa 
toad now or in the foreseeable future.
    Mosquito fish (Gambusia affinis) have been introduced into waters 
of Oasis Valley and occur at most sites occupied by toads. Mosquito 
fish have been observed to prey on eggs of the arroyo toad (Anaxyrus 
(=Bufo) californicus; Lannoo 2005, p. 399) and may also prey on 
Amargosa toad eggs. During our review of the status of the Amargosa 
toad, no information was available that suggests mosquito fish are 
important predators of toad eggs. No observations of mosquito fish 
preying on toad eggs have been reported during the 12 years of 
population monitoring. NDOW is actively working with a variety of 
partners, including Nye County, to limit the use and distribution of 
mosquito fish in the Oasis Valley and to develop alternative vector 
control strategies that do not use mosquito fish as the control agent. 
We have no information to indicate that the presence of, or predation 
by, mosquito fish is a significant threat to the Amargosa toad or that 
such predation will become a threat in the foreseeable future.
Summary of Factor C
    Based on a review of the best available scientific and commercial 
data, we find no indication of a potential threat of disease. We have 
no reason to conclude disease is currently or will become a threat to 
the species in the foreseeable future, due to an absence of sign of 
disease in Amargosa toads. Predation by bullfrogs, crayfish, and 
mosquito fish continues to affect Amargosa toad populations but not to 
an extent that threatens the species. Largemouth bass do generally 
occur in waters occupied by toads and do not substantially affect the 
toad. Based on the best scientific information available, there is no 
indication that predation is resulting in negative population wide 
effects. Completed actions prescribed in the CAS to conserve the 
Amargosa toad have been shown to be successful in meeting the 
objectives in the CAS and reducing or eliminating the threats to the 
Amargosa toad under Factor C. Therefore, after a review of the best 
scientific and commercial information, we conclude disease and 
predation are not significant threats to the Amargosa toad and are not 
likely to become significant threats in the foreseeable future. This 
determination is based on the absence of signs of disease; Amargosa 
toad metapopulation structure; habitat projects that select for toads; 
the life history of the toad; and 12 years of toad population 
monitoring data that shows toads can coexist with nonnative predators.

Factor D. The Inadequacy of Existing Regulatory Mechanisms

    The petitioners claim the existing regulatory mechanisms, including 
Nevada State law protections, have been ineffective in preventing the 
decline of and mitigating the principal threats to the species. The 
petitioners claim 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 (CBD and PEER 2008, pp. 20 and 28). 
Generally, domestic wells that draw less than 1,800 gallons per day do 
not require a permit (NRS 534.180). However, the NSE may require the 
registration of domestic wells in certain groundwater basins that it 
designates and may limit the amount of groundwater extracted from a 
permitted well to an amount below the full permitted amount under 
certain conditions. No declines in groundwater levels or toad numbers 
have been observed at monitored sites as a result of groundwater 
pumping. In our review in Factor A, we concluded that Amargosa toad 
populations have not been affected and are not likely to become 
affected by groundwater extraction. Groundwater use is currently 
consistent with historic use and will not likely increase due to lack 
of growth in the area.
    The Amargosa toad was classified as a protected amphibian by the 
State of Nevada through an action of the Nevada Board of Wildlife 
Commissioners in 1998, under authority of NAC 503.075, and NAC 503.090 
provides that no open season shall be designated for species of 
resident wildlife classified as protected which includes collection or 
possession. Through NDOW, the State plays an important role in ensuring 
conservation actions are achieved for this species under these and 
other authorities.
    The Amargosa toad is designated by the BLM Nevada State Director as 
a BLM sensitive species. This requires BLM to ensure that actions they 
authorize, fund, or carry out do not contribute to the need to list the 
species as threatened or endangered (BLM Manual section 6840.06 C). The 
BLM's Tonopah Resource Management Plan and Record of Decision (RMP) 
determined that habitat for BLM sensitive species be managed to 
maintain or increase current populations of these species (BLM 1997, p. 
9).
    The petitioners identified privately owned Amargosa toad habitat 
and the lack of a final master plan for the Oasis Valley as potential 
threats to the toad. Considering the limited extent and use of private 
lands in Oasis Valley, a master plan would likely be unnecessary to 
guide development. However, on November 3, 2009, the Nye County Board 
of County Commissioners approved the Beatty Open Space Plan (Stantec 
Consulting 2009, pp. 1-45 plus appendices). This final plan provides 
the framework by which the County may pursue more specific actions to 
preserve BLM land for the benefit of the Town of Beatty and private 
land for the preservation of Amargosa toad habitat and a walking trail 
along the Amargosa River. Open space in the plan is defined as land 
that is not intensively developed for residential, commercial, 
industrial, or institutional use. The plan identifies 26,778 ac (10,837 
ha) of land administered by the BLM as open space, which includes most 
of the range of the Amargosa toad (Stantec Consulting 2009, Appendix 
A). The broad goals for the Beatty Open Space Plan as defined by the 
stakeholders include: Install signage and implement a community-wide 
education program on the importance of staying out of the riverbed, 
particularly with ATVs, to protect the toad habitat; protect sensitive 
habitats; and identify appropriate activities in Amargosa toad habitat 
(Stantec Consulting 2009, p. 24). As a signatory to the CAS, Nye County 
committed to coordinate conservation with the local community such as 
development of the open space plan (NDOW 2000, p. A-15). We conclude 
that the completion of a final open space plan is an important 
conservation achievement that demonstrates the cooperative relationship 
and strong partnership among all levels of government, Beatty 
landowners, and the Beatty community. Adoption of an open space plan 
and BLM's protection of Amargosa toad habitat through implementation of 
the Tonopah RMP provide some mechanisms that reduce the potential 
threats to the species.

[[Page 42051]]

Summary of Factor D
    We have reviewed the best available scientific and commercial 
information, and conclude that the Amargosa toad is not threatened by 
the existence of inadequate regulatory mechanisms. There are no 
significant threats to the species, and Amargosa toad populations are 
stable based on annual population estimates.

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

    In our 90-day finding, we concluded that natural or manmade 
factors, particularly small populations, small range size, and 
environmental changes due to climate change, could exacerbate threats 
identified under Factor A. In this 12-month finding, we determined that 
no significant threats were found under Factor A.
Small Range and Population Size
    The range of the Amargosa toad is approximately 8,440 ac (3,416 ha) 
and the rangewide total number of adult toads is estimated at 2,500 to 
4,000 toads. No reductions in the range of the Amargosa toad have been 
documented. Although no historic estimates of population size are known 
(NDOW 2009, p. 1), there is also no indication that historical 
population levels were significantly higher than current levels. 
Population data collected over the past 12 years show 5 years of 
population increases, 6 years of declines, and data for 2000 was 
essentially the same as 1999; no declines occurred over any consecutive 
3-year period (Hobbs 2009, p. 2). Amargosa toad data collected by NDOW 
as prescribed in the CAS (NDOW 2000, p. A-13), and as part of the mark-
recapture program document individual toad movements among 
metapopulations and across dry desert uplands to remote Trespass Seep 
and from the Harlan-Keal site to the river south of Beatty 
(approximately 8 mi (13 km)). Amargosa toad metapopulations are mostly 
limited by habitat conditions. Amargosa toads disperse among sites when 
habitat conditions are suitable, and Amargosa toad numbers at any given 
site can range from historic lows to record highs in one year (Hobbs 
2009, pp. 1-6). Small population and small range sizes are not 
necessarily threats to a species. With the ability to move across large 
expanses of unsuitable habitat, and recolonize suitable habitat 
patches, the Amargosa toad exhibits a classic and strong metapopulation 
structure. This allows the Amargosa toad to take advantage of newly 
available resources, or quickly rebound after localized population 
extirpations. Therefore, we conclude that the small range and 
population size of the species is not a significant threat to the 
species, nor do we expect the range or population size to decrease in 
the foreseeable future due for the reasons stated above.
Climate Change
    The Intergovernmental Panel on Climate Change (IPCC) has high 
confidence in predictions that extreme weather events, warmer 
temperatures, and regional drought are very likely to increase in the 
northern hemisphere as a result of climate change (IPCC 2007, pp. 15-
16). Climate models show the southwestern United States has 
transitioned into a more arid climate of drought that is predicted to 
continue into the next century (Seager et al. 2007, p. 1181). In the 
past 60 years, the frequency of storms with extreme precipitation has 
increased in Nevada by 29 percent (Madsen and Figdor 2007, p. 37). 
Changes in local southern Nevada climatic patterns cannot be 
definitively tied to global climate change; however, they appear to be 
consistent with IPCC-predicted patterns of extreme precipitation, 
warmer than average temperatures, and drought. Information on specific 
effects from climate change to the Amargosa toad and to individual 
habitats and aquatic systems is not available, and effects are 
difficult to predict and likely to vary from site to site over time. 
However, as detailed under Factor A, previous habitat improvements on 
the Amargosa River, Harlan-Keal, Mullin, and Spicer sites have all 
resulted in substantial positive responses by Amargosa toads. To meet 
objectives under the CAS, Amargosa toad conservation partners have 
implemented design strategies and are continuing to develop and 
implement appropriate strategies that build resiliency into habitat 
projects. We conclude that continuing to maintain and actively manage 
the matrix of habitats that support the population of the Amargosa toad 
reduces the potential threat of climate change to the toad to the 
extent that Amargosa toads will continue to occupy most sites currently 
occupied by the species which will continue into the foreseeable 
future. In the absence of active management, several spring sites may 
become degraded; however, the river and larger spring sites are 
expected to maintain their function to provide the ecological needs for 
the species.
Stochastic Events
    The petitioners claim stochastic events such as drought, floods, 
and fires are threats to the Amargosa toad because of the limited 
distribution of the toad. Major flood events have occurred in the 
Amargosa River; however, Amargosa toads continue to occur in the river 
and may benefit from the disturbance created by such events. Although 
floods may result in short-term adverse effects to the Amargosa toad, 
the disturbance created by flooding events may scour dense emergent 
vegetation and create and increase open water pools that are preferred 
by the species.
    Some studies suggest that amphibian responses to fire and 
associated habitat alteration are species-specific, incompletely 
understood, and variable among habitats and regions (Pilliod et al. 
2003, p. 165). We found no information that any wildfire occurred in 
Amargosa toad habitat in recent history. However, controlled burns on 
TNC properties have resulted in positive responses by toads by reducing 
emergent aquatic vegetation and providing open water (ATWG 2009, p. 3) 
that is beneficial to the species.
    The metapopulation structure of the Amargosa toad allows local 
extirpations and recolonization following stochastic events. Such 
fluctuation in Amargosa toad numbers has been observed after prescribed 
burns and habitat improvement projects that resulted in disturbance to 
Amargosa toad habitat. Drought effects on the Amargosa toad may include 
a reduction of surface water, prey, and wetland habitat; however, we 
found no evidence of long-term effects to the Amargosa toad as a result 
of drought. We expect stochastic events to occur periodically in the 
future; however toads may benefit from the disturbance. If the number 
of toads at a given site is reduced or toads become extirpated from a 
site, we expect recolonization to occur from other metapopulations. 
Therefore, we do not expect stochastic events to be a threat to the 
toad in the foreseeable future.
Contaminants
    Radiation poisoning through groundwater contamination from atomic 
testing on the Nevada Test Site (NTS) was cited as a threat by the 
petitioners (CBD and PEER 2008, p. 21). The movement of radiation in 
groundwater in Oasis Valley is currently being studied. Geologic faults 
allow alluvial groundwater connection between the Amargosa River and 
the Pahute Mesa aquifer, which includes areas used for atomic testing 
(Reiner et al. 2002, p. 61). There have been no reports of abnormal 
toads, reduced reproduction, or death of multiple toads at any given 
site that would suggest radiation or contaminant

[[Page 42052]]

effects. In 2006, DOE contracted sampling of nine wells and three 
springs in Oasis Valley wells for radioactivity (tritium) in 
groundwater (DOE 2006, pp. 4.1-4.30). The investigators concluded that 
no groundwater (wells or springs) sampled downgradient of the NTS, 
including Oasis Valley where Amargosa toads occur, had been impacted by 
NTS nuclear test operations as of 2006. In all cases, measured tritium 
levels in wells and springs sampled in Oasis Valley were below or just 
above the laboratory detection limit, and three orders of magnitude 
less than the U.S. Environmental Protection Agency established maximum 
contaminant level for drinking water. Because the Town of Beatty uses 
groundwater from the Oasis Valley, monitoring for potential 
contaminants in groundwater will continue for human health. Based on 
the available information, there is no indication that radioactive 
groundwater is a concern for the Amargosa toad, or that radioactive 
groundwater from the Pahute Mesa aquifer will become a threat to the 
toad in the foreseeable future.
    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). During monitoring of toad populations from 1998 to 2009 as 
prescribed in the CAS, no environmental evidence was observed to 
suggest that contaminants from private lands are affecting Amargosa 
toads. Although Amargosa toads have not been examined to assess 
contaminant levels, no Amargosa toad developmental anomalies or die-
offs have been reported. Due to the high level of monitoring and close 
proximity to residents who consistently communicate with the Service on 
the Amargosa toad, we believe any detrimental environmental effects 
would be observed and reported. Therefore, we conclude that 
contaminants are not a threat to the toad. We do not anticipate that 
contaminants will become a threat to the toad in the foreseeable future 
due to our expectation that the metapopulation structure will persist 
and monitoring will continue which would detect any effects of 
contaminants at the level of the individual or population.
    The petitioners claim that the CAS failed to protect Amargosa toads 
and increase toad populations. The CAS is a voluntary and non-
regulatory agreement. As discussed above, the CAS has proven to be an 
effective tool in furthering the long term conservation of the species, 
as well as reducing or eliminating the threats to the species. Please 
see our discussion for specific information regarding the CAS in the 
background section of this finding. Based on implementation of various 
conservation actions resulting from the CAS as discussed in the factors 
above, we find that the existence and implementation of the CAS do not 
pose a threat to the species.
Summary of Factor E
    We have reviewed the best available scientific and commercial 
information and find that small range and population size, climate 
change, stochastic events, or contaminants are not significant threats 
to the species. While we have no Amargosa toad population estimates 
prior to the mid-1990s, the best available information indicates that 
the historic range of the toad approximates its current range. Based on 
12 years of population monitoring data, toad populations estimates are 
stable. The range and population numbers will not decrease in the 
foreseeable future in consideration of the habitat improvements 
identified in Factor A and overall absence of significant threats to 
the species. While climate change effects are mostly uncertain, we 
conclude that sufficient resiliency has been provided to the toad 
through project that established of a matrix of habitats and 
metapopulations. Stochastic events will continue but will benefit the 
toads by providing disturbance or result in recolonization from 
adjacent populations. Monitoring and oversight by the signatories of 
the CAS, ATWG, and local landowners will continue and detect any 
impacts to the toad that may result from contaminants. Therefore, we 
conclude that other natural or manmade factors are not affecting the 
continued existence of the Amargosa toad, now or in the foreseeable 
future.

Finding

    As required by the Act, we considered the five factors in assessing 
whether the Amargosa toad is threatened or endangered throughout all or 
a significant portion of its range. We examined the best scientific and 
commercial information available regarding the past, present, and 
future threats faced by the Amargosa toad. We reviewed the petition, 
information available in our files and other available published and 
unpublished information, and we consulted with recognized Amargosa toad 
experts and other Federal, State, local agencies, and nongovernment 
organizations. 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 warrants 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 
identification of factors that could impact a species negatively is not 
sufficient to compel a finding that listing is appropriate; we require 
evidence that these factors are operative threats that act on the 
species to the point that the species meets the definition of 
threatened or endangered under the Act.
    We analyzed the potential threats to the Amargosa toad including: 
Private land development resulting in habitat loss and water use; 
groundwater development/extraction; habitat degradation including 
overgrowth of vegetation; grazing and trampling by livestock; 
recreation and OHV activity; invasive plants species; disease; 
predation by nonnative bullfrogs, crayfish, and fishes; lack of 
regulatory control of residential groundwater withdrawal; inadequate 
protection on privately owned land including lack of a final master 
plan for the Oasis Valley; small range and population size; climate 
change; stochastic events; and contaminants.
    We found that habitat loss as a result of development on private 
land is not a substantial threat to the Amargosa toad, and we do not 
believe that the toad population is declining rangewide. In addition, 
we found no indication that the human population will increase beyond 
historic levels, and we do not anticipate an increase in future use of 
groundwater to support new residential development in the Town of 
Beatty and Oasis Valley. Based on the volume, timing, and location of 
groundwater withdrawal; historic use of groundwater, and water-level 
measurements, we concluded that water use and development in Oasis 
Valley are not a substantial threat to the Amargosa toad. Overgrowth of 
vegetation in aquatic habitats is an ongoing management concern for the 
Amargosa toad because it can result in degraded habitat. However, 
various tools, such as habitat improvement and

[[Page 42053]]

enhancement projects, have been and continue to be implemented to 
manage this potential threat to the Amargosa toad. Continued 
implementation of conservation actions as outlined in the CAS by 
regulatory agencies and a coalition of partners has reduced and 
continues to minimize threats to the Amargosa toad. Light to moderate 
ungulate grazing and trampling are not a substantial threat to the toad 
and likely provide some benefit to the habitat for the Amargosa toad. 
Excessive ungulate grazing in Amargosa toad habitat is localized and 
mostly occurs in the Amargosa River channel south of Beatty. Use by 
OHVs, particularly in wet areas (along the Amargosa River), can be an 
issue, especially when Amargosa toad eggs and tadpoles are present. 
However, efforts have been undertaken (e.g., rerouting of OHV races out 
of habitat) or are proposed to reduce OHV use in these areas so that 
OHV use is not a significant threat to the species. In addition, no 
spring sites have been identified that are substantially affected by 
OHV activity. Efforts to remove salt cedar and other nonnative, 
invasive plants from the Amargosa River watershed have occurred since 
2003. Efforts will continue to remove salt cedar and replace it with 
native shrubs and trees, which may improve toad habitat and increase 
toad numbers. We conclude that the present or threatened destruction, 
modification, or curtailment of toad habitat or its range is not a 
significant threat to the Amargosa toad now or in the foreseeable 
future.
    We found no information that overcollection or overutilization for 
commercial, recreational, scientific, or educational purposes is a 
threat or will become a threat to the species in the future. Therefore, 
we find overutilization for commercial, recreational, scientific, or 
educational purposes does not threaten the Amargosa toad now or in the 
foreseeable future.
    We also found no evidence that chytrid or other diseases are 
affecting the Amargosa toad population, and therefore, disease does not 
threaten the Amargosa toad. Predation by nonnative species has 
affected, and will continue to affect Amargosa toad populations; 
however, metapopulations are allowing the coexistence of the Amargosa 
toad with predators and competitors. Amargosa toad populations appear 
to be generally stable over the long-term, including sites where toads 
coexist with nonnative predators and competitors. Habitat projects have 
been designed and constructed to provide an advantage to Amargosa toads 
and reduce numbers of nonnative predators. Therefore, we conclude that 
disease or predation are not significant threats to the Amargosa toad 
now or in the foreseeable future.
    The Amargosa toad is classified as a protected amphibian by the 
State of Nevada under authority of NAC 503.075, and it is also 
designated as a BLM sensitive species in Nevada. Completion of a final 
open space plan for the Oasis Valley, approved by the Nye County Board 
of Commissioners, indicates a cooperative conservation effort among all 
levels of government, Beatty landowners, and the Beatty community to 
protect Amargosa toad habitat.
    The current range of the Amargosa toad is approximately the same, 
and possibly larger, than its historical range as a result of 
conservation efforts accomplished by the various entities working to 
ensure long-term conservation of the Amargosa toad. In summary, we 
concluded that inadequate regulatory mechanisms are not a threat to the 
Amargosa toad now or in the foreseeable future.
    The range and small population size of the toad have characterized 
the species during modern times with no significant changes. Current 
monitoring efforts will continue and inform the ATWG and others of any 
habitat improvement needs for the species. Climate change is likely to 
continue for the foreseeable future, but there is substantial 
uncertainty as to how climate change will affect the Amargosa toad and 
its habitat. We found no information to suggest that climate change 
will result in an altered landscape to the extent that it will 
negatively affect Amargosa toads. Stochastic events (such as floods, 
fire and drought) have occurred on the landscape where Amargosa toads 
occur in Oasis Valley. The metapopulation structure of the Amargosa 
toad would allow local extirpations as a result of these stochastic 
events, but also recolonization following the events. Controlled burns 
have resulted in positive responses by Amargosa toads by reducing 
vegetation and providing open water. By maintaining and actively 
managing the matrix of habitats that support the population of the 
Amargosa toad, the uncertainties and threats of climate change and 
stochastic events should be reduced. The ability to modify site 
conditions where Amargosa toads occur in response to environmental 
changes has been demonstrated as a significant management tool for 
Amargosa toad conservation efforts to address various threats, 
including stochastic events and invasive species, as well as possible 
changed conditions from climate change in the future. No environmental 
evidence has been observed to suggest that contaminants from private 
lands are affecting Amargosa toads. We believe any detrimental 
environmental effects would be observed and reported to the Service or 
NDOW. Continued implementation of conservation actions as outlined in 
the 2000 CAS by NDOW, other signatories, and a coalition of partners 
has reduced and continues to minimize threats to the Amargosa toad. We 
conclude that other natural or manmade factors are not significant 
threats to the Amargosa toad now or in the foreseeable future.
    Based on our review of the best available scientific and commercial 
information pertaining to the five factors, we find that the threats 
are not of sufficient imminence, intensity, or magnitude to indicate 
that the Amargosa toad is in danger of extinction (endangered), or 
likely to become endangered within the foreseeable future (threatened). 
Therefore, we find that listing the Amargosa toad as a threatened or 
endangered species is not warranted.

Evaluation of Distinct Population Segment (DPS)

    Having determined that the Amargosa toad does not meet the 
definition of a threatened or endangered species, we must next consider 
whether there are any segments within the population that meet the 
Service's DPS policy. Under the DPS policy (61 FR 4722; February 7, 
1996), three elements are considered in the decision concerning the 
establishment and classification of a possible DPS. These are applied 
similarly for additions to or removal from the Federal List of 
Endangered and Threatened Wildlife. These elements include:
    (1) The discreteness of a population in relation to the remainder 
of the species to which it belongs;
    (2) The significance of the population segment to the species to 
which it belongs; and
    (3) The population segment's conservation status in relation to the 
Act's standards for listing, delisting, or reclassification (i.e., is 
the population segment endangered or threatened).
    Under the DPS Policy, we must first determine whether the 
population qualifies as a DPS; this requires a finding that the 
population is both: (1) Discrete in relation to the remainder of the 
species to which it belongs; and (2) biologically and ecologically 
significant to the species to which it belongs. If the population meets 
the first two criteria under the DPS policy, we then proceed

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to the third element in the process, which is to evaluate the 
population segment's conservation status in relation to the Act's 
standards for listing as an endangered or threatened species. The DPS 
evaluation in this finding concerns the Amargosa toad that we were 
petitioned to list as threatened or endangered.

Discreteness

    Under the DPS Policy, a population segment of a vertebrate taxon 
may be considered discrete if it satisfies either one of the following 
conditions:
    (1) It is markedly separated from other populations of the same 
taxon as a consequence of physical, physiological, ecological, or 
behavioral factors. Quantitative measures of genetic or morphological 
discontinuity may provide evidence of this separation. (2) It is 
delimited by international governmental boundaries within which 
differences in control of exploitation, management of habitat, 
conservation status, or regulatory mechanisms exist that are 
significant in light of section 4(a)(1)(D) of the Act.

Markedly Separated From Other Populations of the Taxon

    As described previously (see Species Information above), the 
Amargosa toad is characterized by metapopulations across its range. 
Individual Amargosa toads move among these metapopulations, and there 
is no indication that physical, physiological, ecological, or 
behavioral barriers exist that would render any portions of the 
species' range markedly separate from other portions. Furthermore, we 
have no quantitative data such as genetic information to suggest any 
portions of the species to be markedly separate from others. Therefore, 
we conclude there are no portions of the species' range that meet the 
discreteness criterion of the Service's DPS policy. Since both 
discreteness and significance are required to satisfy the DPS policy, 
we have determined that there are no populations of the Amargosa toad 
that qualify as a DPS under our policy. As a result, no further 
analysis under the DPS policy is necessary.

Significant Portion of the Range

    Having determined that the Amargosa toad does not meet the 
definition of a threatened or endangered species, we must next consider 
whether there are any significant portions of the range where the 
Amargosa toad is in danger of extinction or is likely to become 
endangered in the foreseeable future.
    We considered whether any portions of the Amargosa toad's range 
warrant further consideration. We found that there is no area within 
the range of the Amargosa toad where the potential threat of 
development or groundwater withdrawal is significantly concentrated or 
may be substantially greater than in other portions of the range. Some 
sites including Crystal and Lower Indian Springs may become overgrown 
with vegetation and cause the site to become unsuitable and require 
rehabilitation. Cattle and feral burros may provide the necessary 
disturbance to improve and maintain Amargosa toad habitat but may cause 
short-term overuse of some sites. Use by OHVs may cause localized 
impacts but we do not anticipate these effects to result in population 
declines. Although nonnative toad predators such as crayfish, 
bullfrogs, and mosquito fish occur throughout much of the range of the 
toad and likely impact the toad to some extent, we have found that 
toads have, and will continue to coexist with these predators. There is 
no indication that stochastic events, climate change, or environmental 
contaminants differentially affect any given site.
    On the basis of our review, we found no areas within the species' 
range where threats are geographically concentrated. The species is 
characterized by metapopulations across its range which allows for an 
individual site to be extirpated and become repopulated from 
neighboring populations. The factors affecting the species are 
essentially uniform throughout its range, indicating that no portion of 
the Amargosa toad's range warrants further consideration of possible 
threatened or endangered status.
    We do not find that the Amargosa toad is in danger of extinction 
now, nor is it likely to become endangered within the foreseeable 
future throughout all or a significant portion of its range. Therefore, 
listing the Amargosa toad as threatened or endangered under the Act is 
not warranted throughout all or a significant portion of its range at 
this time.
    We request that you submit any new information concerning the 
status of, or threats to, the Armargosa toad to our Nevada Fish and 
Wildlife Office (see ADDRESSES section) whenever it becomes available. 
New information will help us monitor the Amargosa toad and encourage 
its conservation. If an emergency situation develops for the Amargosa 
toad, we will act to provide immediate protection.

References Cited

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

Author(s)

    The primary authors of this notice are staff with the Nevada Fish 
and Wildlife Office, Las Vegas.

Authority

    The authority for this section is section 4 of the Endangered 
Species Act of 1973, as amended (16 U.S.C. 1531 et seq.).

    Dated: July 9, 2010
Wendi Weber,
Acting Director, Fish and Wildlife Service.
[FR Doc. 2010-17647 Filed 7-19- 10; 8:45 am]
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