[Federal Register: October 12, 2000 (Volume 65, Number 198)]
[Proposed Rules]               
[Page 60607-60609]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]



Fish and Wildlife Service

50 CFR Part 17

Endangered and Threatened Wildlife and Plants: 90-day Finding on 
a Petition To List the Yosemite Toad as Endangered

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Notice of 90-day petition finding.


SUMMARY: The U.S. Fish and Wildlife Service (Service) announces a 90-
day finding on a petition to list the Yosemite toad (Bufo canorus) as 
endangered under the Endangered Species Act (Act) of 1973, as amended 
(16 U.S.C. 1531 et seq.). We find that the petition presents 
substantial scientific or commercial information to indicate that 
listing the species may be warranted. Therefore, we are initiating a 
status review to determine if the petition action is warranted. To 
ensure that the review is comprehensive, we are asking for information 
and data regarding this species.

DATES: The finding announced in this document was made on October 5, 
2000. To be considered in the 12-month finding for this petition, 
comments and information should be submitted to the Service by December 
11, 2000.

ADDRESSES: Data, information, comments, or questions concerning this 
petition should be submitted to the Field Supervisor; Sacramento Fish 
and Wildlife Office; Sacramento Fish and Wildlife Office; 2800 Cottage 
Way, Room W-2065; Sacramento, California 95825. The petition finding, 
supporting data and comments are available for public inspection, by 
appointment, during normal business hours at the above address.

FOR FURTHER INFORMATION CONTACT: Jason Davis or Maria Boroja at the 
Sacramento Fish and Wildlife Office (see ADDRESSES section above), or 
at (916-414-6600.



    Section 4(b)(3)(A) of the Endangered Species Act (Act) of 1973, as 
amended (16 U.S.C. 1531 et seq.), requires that the Service make a 
finding on whether a petition to list, delist, or reclassify a species 
presents substantial information indicating that the petitioned action 
may be warranted. To the maximum extent practicable, this finding is to 
be made within 90 days of the receipt of the petition, and the finding 
is to be published promptly in the Federal Register. If the finding is 
that substantial information was presented, the Service will commence a 
review of the status of the involved species. This finding is based on 
information contained in the petition, supporting information submitted 
with the petition, and other information available to the Service at 
the time the finding was made.
    The processing of this petition conforms with the Service's final 
listing priority guidance published in the Federal Register on October 
22, 1999 (64 FR 57114). The guidance clarifies the order in which we 
will process rulemakings. Highest priority is processing emergency 
listing rules for any species determined to face a significant and 
imminent risk to well-being (Priority 1). Second priority (Priority 2) 
is processing final determinations on proposed additions to the lists 
of endangered and threatened wildlife and plants. Third priority 
(Priority 3) is processing new proposals to add species to the lists. 
The processing of administrative petition findings (petitions filed 
under section 4 of the Act) is the fourth priority (Priority 4). The 
processing of critical habitat determinations (prudency and 
determinability decisions) and proposed or final designations of 
critical habitat will be funded separately from other section 4 listing 
actions and will no longer be subject to prioritization under the 
listing priority guidance. The processing of this petition finding is a 
Priority 4 action.
    We have made a 90-day finding on a petition to the list Yosemite 
toad (Bufo canorus) as an endangered species. On Monday, April 3, 2000, 
we received a

[[Page 60608]]

petition, dated February 28, 2000, to list the Yosemite toad as 
endangered. The petition was submitted by the Center for Biological 
Diversity and Pacific Rivers Council. The letter clearly identified 
itself as a petition and contained the names, signatures, and addresses 
of the petitioners. Included in the petition was supporting information 
relating to the species' taxonomy and ecology, adequacy of existing 
regulatory mechanisms for the species, and the historic and present 
distribution, current status, and potential cause of decline. This 
notice constitutes the 90-day finding for the February 28, 2000, 
    The Yosemite toad is a high elevation species that occurs in the 
central Sierra Nevada Mountains of California (Stebbins 1985). The 
range of the Yosemite toad extends from Ebbetts Pass, Alphine County, 
to south of Kaiser Pass and Evolution Lake, Fresno County (Stebbins 
1966, Karlstrom 1962, 1973). According to the petition, the Yosemite 
toad commonly occurs at elevation between 2,438 and 3.047 meters (8,000 
and 10,000 feet), with an overall elevation range of 1,950 to 3,500 
meters (6,400 to 11,300 feet).
    The Yosemite toad is a member of the Boreas-canorus group, the most 
primitive of three evolutionary lines of North American Bufo (Camp 
1917, Karlstrom 1962). According to Camp (1916), the Yosemite toad has 
long been recognized as a distinct species. The Yosemite toad is a 
close relative of three toad species, the western toad (Bufo boreas), 
black toad (Bufo exsul), and Amargosa toad (Bufo nelsoni) (Blair 1972, 
Stebbins 1985). The petitioners state that Yosemite/western toad 
hybridization occurs in the northern portion of the Yosemite toad's 
range in the Blue Lake region of the Carson-Iceberg Wilderness, just 
southeast of Carson Pass in Alphine County (Karlstrom 1973, Stebbins 
    The petition and accompanying documentation state that the species 
qualifies for listing pursuant to the Act due to potential habitat 
destruction and modification, the presence of disease in combination 
with natural predation, the inadequacy of existing regulatory 
mechanisms, and other natural or human-caused factors affecting its 
continued existence. The petitioners contend that natural and human-
induced changes to Yosemite toad habitats, including (1) livestock 
grazing, (2) contaminant introductions, (3) non-native fish 
introductions, (4) disease (5) ultraviolet radiation, (6) climate 
change, (7) acid deposition, (8) drought, and (9) other factors, 
separately and in combination, are responsible for the range-wide 
decline of the species.
    There have been few if any studies to date on the direct effect of 
contaminant introductions on Yosemite toad populations. However, 
several studies show that significant levels of contaminants have been 
deposited in high Sierran aquatic ecosystems from pesticide drift, acid 
precipitation, and smog drift (Seiber et al. 1998, Aston and Seiber 
1997, Cahill et al. 1996, Miller 1996, Byron 1991, Nikolaidis 1991, 
Laird et al. 1986). The petitioners believe that contaminant 
introductions can harm toad populations through lethal and sublethal 
effects including delayed metamorphosis, reduced breeding and feeding 
activity (Berrill et al. 1993, 1994, 1995,1998, Boyer and Grue 1995, 
Beaties and Tyler-Jones 1992, Corn and Vertucci 1992, Hall and Henry 
1992). In addition, contaminant introduction may weaken the immune 
systems of toads rendering them more susceptible to disease such as 
chytrid fungus and red-legged disease (Aeromonas hydrophila) (Carey et 
al. 1993, 1995, 1999, Jennings 1996, Drost and Fellers 1996, Sherman 
and Morton 1993).
    There is ample evidence to suggest that Yosemite toads cannot 
coexist with introduced fish. In addition, there are strong indications 
that nonnative fish introductions have contributed to the decline of 
the toad. Not only do nonnative fish prey upon adult, juvenile and 
larval toads, they also alter the food chain of high Sierran aquatic 
ecosystems (Knapp 1996, Jennings 1996, Bradford 1989, 1993). The 
petitioners state that the most significant effect of nonnative fish on 
Yosemite toads is that they preclude the use of the deeper and more 
permanent water bodies that provide refuge for toads during periods of 
prolonged drought. The loss of higher quality, permanent breeding 
habitats for Yosemite toads disrupts their ability to recolonize 
peripheral areas after long periods of drought, and renders them more 
susceptible to localized extinctions (Knapp 1996, Drost and Fellers 
1994, 1996, Bradford et al. 1993).
    The petitioners state that disease likely plays a significant role 
in the widespread decline of Yosemite toad populations. Two diseases 
that may affect Yosemite toads are red-legged disease, which is caused 
by a freshwater bacteria, and chytrid fungus. Sherman and Morton (1984, 
1993) noted the mortality of adult Yosemite toads due to red-legged 
disease at Tioga Pass during the 1970's. Chytrid fungus, an aquatic 
pathogen discovered after 1993, has caused mortality in many amphibian 
species in the United States and worldwide. An investigation of museum 
specimens of Yosemite toads collected by Sherman and Morton at Tioga 
Pass during a die-off in 1977-1978 found those toads to be infected 
with chytrid fungus (Carey et al. 1999). The petitioners state that 
there is significant information yet to be discovered regarding aquatic 
pathogens and their relationship to the ecology of Yosemite toads. 
Should evidence indicate that Yosemite toads have evolved with aquatic 
pathogens, then other stressors including contaminant introductions and 
UV-radiation may be reducing the ability of toads to fight off 
infection from these pathogens (Sherman and Norton 1993, Drost and 
Fellers 1996, Carey et al. 1993, 1995, 1999, Jennings 1996, Taylor et 
al. 1999).
    The petitioners state that there are other natural and 
anthropogenic factors that may be negatively affecting the Yosemite 
toad, including (1) airborne contamination, (2) ultraviolet radiation, 
and (3) climate change. However, there are significant gaps in the 
extent of the information regarding affects of airborne contaminants on 
Yosemite toads. The affect of UV-radiation and global warming on 
Yosemite toad populations is also lacking at this time. These factors 
may provide additional stresses on toad populations that are already 
being assaulted by nonnative fish, livestock grazing, drought, and 
disease. Combinations of stresses may explain the significant declines 
of Yosemite toads recorded over the past few decades.
    Several studies and observations made within the first half of the 
twentieth century report that Yosemite toads were abundant throughout 
their range, especially within Yosemite National Park (Grinnell and 
Storer 1924, Karlstrom 1962, Mullally 1953, Mullally and Cunningham 
1956, Yosemite National Park Office 1999). More recent studies 
indicated that Yosemite toads have suffered significant declines in 
both abundance and distribution throughout their range. Jennings and 
Hayes (1994) reported that, even though Yosemite toads occur in areas 
that are free from physical disturbance, the species has declined or 
disappeared from 50 percent of known historic sites.
    Within Yosemite National Park, the heart of the Yosemite toad's 
range, there are several documented declines in the distribution and 
abundance of Yosemite toad populations. Drost and Fellers (1994, 1996) 
resurveyed areas within the park that were originally surveyed in the 
first quarter of last century by the U.C. Berkeley survey team lead by 
Grinnell and Storer. By the 1990s, Yosemite toads only occupied 50

[[Page 60609]]

percent of these sites. The petitioners note that in a subsequent 
amphibian survey within Yosemite National Park, Fellers (1997) found 5 
locations occupied by Yosemite toads out of 260 survey sites. The 
petitioners do not report whether these 260 survey locations were 
historically occupied by Yosemite toads. Additionally, several other 
sites that once supported abundant Yosemite toad populations including 
Tioga Pass, Sylvester Meadows, and several nearby sites have shown 
complete disappearances of toads in recent years (Karlstrom 1962, 
Sherman and Morton 1993). Sherman and Morton (1993) further documented 
significant declines in toad populations at their Tioga Pass Meadow 
study area. They counted an average of 257 toads annually during the 
period of 1974-1978 at Tioga Pass Meadow. By 1982, toad populations had 
declined to 28 individuals and in 1990, only one female, two males, and 
4 to 6 egg masses. In 1991, these researchers noted only two egg masses 
and a single calling male. Other researchers have corroborated this 
decline (Drost and Fellers 1994). Additional population declines of 
Yosemite toads were observed at Saddlebag Lake, Frog Lake, Hoover Lake, 
and Mildred Lake (Sherman and Morton 1993).
    The trend of populations declines also holds true for sites outside 
of Yosemite National Park. Bradford and Gordon (1992) conducted a 
survey of 235 randomly selected sites in potential Yosemite toad 
habitat above 2,625 meters (8,000 feet) and found only 17 sites 
occupied. In addition, the petitioners cite a survey conducted by David 
Martin (1990) that found of 75 historic localities surveyed throughout 
the high Sierra, only 40 were occupied. During his survey, Martin 
(1990) found no toads at historic locations at elevations below 2,461 
meters (7,500 feet). Furthermore, Martin (1990) reported that of the 40 
sites with toads present, he found an average of 5.75 individuals. The 
petition cites a personal communication with David Martin (San Jose 
State University, pers. comm. 2000), indicating that historically, 
Yosemite toad numbers were estimated to be over 100 individuals per 
site at each of these 75 locations. Additional toad declines have been 
reported by Martin (1992) at Emigrant Meadow and Lunch Meadow in the 
Emigrant Wilderness, Stanislaus National Forest, and around Sonora 
Pass, where toad populations that had once been abundant are now small 
or undetectable. This trend appears to hold for toad populations on the 
El Dorado and Sequoia National Forests (Stebbins 1966).
    We have reviewed the petition and other information available in 
our files. Based upon this review, we believe that substantial evidence 
exists that listing of this species as endangered may be warranted. 
When we make a positive finding, we also are required to promptly 
commence a review of the status of the species. Based upon available 
and any newly obtained information, we will issue a 12-month finding as 
required by section 4(b)(3)(B) of the Act. Petitioners also requested 
that critical habitat be designated for the Yosemite toad; the 12-month 
finding will address this issue.

Public Information Requested

    The Service hereby announces its formal review of the species' 
status pursuant to this 90-day petition finding. We request any 
additional data, comments, and suggestions from the public, other 
concerned government agencies, the scientific community, industry, or 
any other interested parties concerning the status of the Yosemite 
toad. Of particular interest is information regarding: (1) The 
existence and status of additional populations, (2) the implementation 
of any actions that are benefitting the species, and (3) the impact of 
livestock grazing, contaminant introductions, non-native fish 
introductions, disease, ultraviolet radiation, climate change, drought, 
and other factors that may be responsible for the range-wide decline of 
the species.
    If you wish to comment, you may submit your comments and materials 
concerning this finding to the Field Supervisor, Sacramento Fish and 
Wildlife Office (see ADDRESSES section). Our practice is to make 
comments, including names and home addresses of respondents, available 
for public review during regular business hours. Respondents may 
request that we withhold their home address, which we will honor to the 
extent allowable by law. There also may be circumstances in which we 
would withhold a respondent's identity, as allowable by law. If you 
wish us to withhold your name and/or address, you must state this 
request prominently at the beginning of your comment. However, we will 
not consider anonymous comments. To the extent consistent with 
applicable law, we will make all submissions from organizations or 
businesses, and from individuals identifying themselves as 
representatives or officials of organizations or businesses, available 
for public inspection in their entirety. Comments and materials 
received will be available for public inspection, by appointment, 
during normal business hours at the above address.

References Cited

    You may request a complete list of all references we cited, as well 
as others, from the Sacramento Fish and Wildlife Office (see ADDRESSES 
    Author: The primary author of this document is Jason Davis, 
Sacramento Fish and Wildlife Office (see ADDRESSES section).


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

    Dated: October 5, 2000.
Jamie Rappaport Clark,
Director, Fish and Wildlife Service.
[FR Doc. 00-26180 Filed 10-11-00; 8:45 am]