[Federal Register: June 14, 2000 (Volume 65, Number 115)]
[Proposed Rules]               
[Page 37343-37357]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]



Fish and Wildlife Service

50 CFR Part 17

RIN 1018-AF41

Endangered and Threatened Wildlife and Plants; Proposal to List 
the Chiricahua Leopard Frog as Threatened With a Special Rule

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Proposed rule.


SUMMARY: We, the U.S. Fish and Wildlife Service (Service), propose 
threatened status pursuant to the Endangered Species Act of 1973, as 
amended (Act), for the Chiricahua leopard frog (Rana chiricahuensis). 
The Chiricahua leopard frog is now absent from many historical 
localities and numerous mountain ranges, valleys, and drainages within 
its former range. In areas where it is still present, populations are 
often few, small, and widely scattered. Known threats include habitat 
alteration, destruction, and fragmentation, predation by nonnative 
organisms, and disease. Habitat loss results from water diversions, 
dredging, livestock grazing, mining, degraded water quality, and 
groundwater pumping. Problems associated with small population numbers 
and size also threaten the species. Evidence suggests that adverse 
effects from water-borne contaminants may also threaten this species. 
This proposed rule, if made final, would implement Federal protection 
to this species and provide funding for development and implementation 
of recovery actions.

DATES: We must receive comments from all interested parties by 
September 12, 2000. We must receive public hearing requests by July 31, 

ADDRESSES: Send comments and materials to the Field Supervisor, Arizona 
Ecological Services Field Office, U.S. Fish and Wildlife Service, 2321 
West Royal Palm Road, Suite 103, Phoenix, Arizona 85021-4951. Comments 
and information received will be available for public inspection, by 
appointment, during normal business hours at the above address.

FOR FURTHER INFORMATION CONTACT: Jim Rorabaugh, Herpetologist, at the 
above address (telephone 602/640-2720; facsimile 602/640-2730).



    Leopard frogs (Rana pipiens complex), long considered to consist of 
a few highly variable species, are now recognized as a diverse 
assemblage of more than two dozen species (Hillis et al. 1983), with 
many species described in the last 20 years. Mecham (1968) recognized 
two distinct variations of ``Rana pipiens'' in the White Mountains of 
Arizona. One of these, referred to as the ``southern form,'' was 
depicted as a stocky frog with raised folds down both sides of the back 
(dorsolateral folds) that were interrupted and deflected medially 
towards the rear. The other form matched previous descriptions of Rana 
pipiens. Based on morphology, mating calls, and genetic analyses 
(electrophoretic comparisons of blood protein samples), Platz and Platz 
(1973) demonstrated that at least three distinct forms of leopard frogs 
occurred in Arizona, including the southern form. This southern form 
was subsequently described as the Chiricahua leopard frog (Rana 
chiricahuensis) (Platz and Mecham 1979).

[[Page 37344]]

    This new species was distinguished from other members of the Rana 
pipiens complex by a combination of characters, including a distinctive 
pattern on the rear of the thigh consisting of small, raised, cream-
colored spots or tubercles on a dark background, dorsolateral folds 
that were interrupted and deflected medially, stocky body proportions, 
relatively rough skin on the back and sides, and often green coloration 
on the head and back (Platz and Mecham 1979). The species also has a 
distinctive call consisting of a relatively long snore of 1 to 2 
seconds in duration (Davidson 1996, Platz and Mecham 1979). Snout-vent 
lengths of adults range from approximately 54 to 139 millimeters (mm) 
(2.1 to 5.4 inches (in)) (Stebbins 1985, Platz and Mecham 1979). The 
Ramsey Canyon leopard frog (Rana subaquavocalis) is similar in 
appearance to the Chiricahua leopard frog, but it often grows to a 
larger size and has a distinct call that is typically given under water 
(Platz 1993).
    Recent articles in the scientific literature report the extirpation 
and extinction of amphibians in many parts of the world (Berger et al. 
1998, Lips 1998, Laurence et al. 1996, Vial and Saylor 1993, Pechmann 
et al. 1991, Blaustein and Wake 1990). Frogs in the family Ranidae, 
which includes the Chiricahua leopard frog, are particularly affected 
(Sredl et al. 1997, Sredl 1993, Bradford 1991, Clarkson and Rorabaugh 
1989, Hayes and Jennings 1986, Corn and Fogleman 1984). Although these 
population declines are thought to result in many cases from habitat 
loss, predation by introduced predators, or other factors, populations 
are sometimes extirpated from seemingly pristine habitats or from areas 
where no obvious cause of decline can be identified (Meyer and Mikesic 
1998, Sredl 1993, Drost and Fellers 1993, Corn and Fogleman 1984, Hines 
et al. 1981). Although natural long-term fluctuations in the size of 
populations and the number of populations within a species are often 
not well studied, increased extirpation rates and in some cases 
apparent extinction, coupled with recent declining trends in the status 
of many amphibian species is alarming and may represent a very recent 
and rapid global decline of an entire class of vertebrates (Blaustein 
et al. 1994, Wake 1991).
    Observers have speculated that these declines may have resulted 
from one or more factors, including habitat disturbance, predation by 
introduced predators such as nonnative fish and amphibians, disease, 
drought, pesticides, acid rain, heavy metals, increased ultraviolet 
radiation due to atmospheric ozone depletion, over-collection, natural 
events such as severe storms or floods, global warming or other 
climatic events, and as a result of the dynamics of small populations 
and groups of small populations or metapopulations (Berger et al. 1998, 
Lips 1998, Lind et al. 1996, Rosen et al. 1996, 1994; Hale et al. 1995, 
Blaustein et al. 1994, Sredl and Howland 1994, Pounds and Crump 1994, 
Sredl 1993, Bradford 1991, Wyman 1990, Clarkson and Rorabaugh 1989, 
Corn and Fogleman 1984, Baxter and Meyer 1982, Dimmitt 1979).
    The Chiricahua leopard frog is an inhabitant of cienegas (mid-
elevation wetland communities often surrounded by arid environments), 
pools, livestock tanks, lakes, reservoirs, streams, and rivers at 
elevations of 1,000 to 2,710 meters (m) (3,281 to 8,890 feet (ft)) in 
central and southeastern Arizona; west-central and southwestern New 
Mexico; and in Mexico, northern Sonora and the Sierra Madre Occidental 
of Chihuahua (Sredl et al. 1997, Degenhardt et al. 1996, McCranie and 
Wilson 1987, Platz and Mecham 1979). The taxonomic status of frogs in 
southern Chihuahua and possibly Durango is in question. The species has 
been reported from southern Chihuahua and Durango (Hillis et al. 1983, 
Platz and Mecham 1984, 1979); however, Webb and Baker (1984) concluded 
that frogs from southern Chihuahua were not Chiricahua leopard frogs, 
as expected. The range of the species is divided into two parts, 
including--(1) a southern group of populations (the majority of the 
species' range) located in mountains and valleys south of the Gila 
River in southeastern Arizona, extreme southwestern New Mexico, and 
Mexico; and (2) northern montane populations in west central New Mexico 
and along the Mogollon Rim in central and eastern Arizona (Platz and 
Mecham 1979). There are historical records in Pima, Santa Cruz, 
Cochise, Graham, Apache, Greenlee, Gila, Coconino, Navajo, and Yavapai 
counties, Arizona; and Catron, Grant, Hidalgo, Luna, Soccoro, and 
Sierra counties, New Mexico (Sredl et al. 1997, Degenhardt et al. 
1996). Historical records for the Chiricahua leopard frog also exist 
from several sites in northern and central Chihuahua, northern Sonora, 
and possibly southern Chihuahua and Durango (Platz and Mecham 1984, 
1979; Webb and Baker 1984; Hillis et al. 1983).
    Male Chiricahua leopard frogs exhibit variable development of 
vestigial (small, nonfunctional) oviducts. Vestigial oviducts are 
absent in most specimens from the northern populations but are 
generally present in specimens from southern populations (Platz and 
Mecham 1979). This and other characteristics that differ regionally 
throughout the range of the species suggest genetic differentiation. 
This differentiation is being investigated and may result in a 
description of the northern populations as a separate species from the 
southern populations (James Platz, Creighton University, pers. comm. 
1994). If the species is split into two distinct taxa, fewer 
populations would exist within each taxon.
    Chiricahua leopard frogs were either collected or observed at 212 
localities in Arizona (B. Kuvlesky, Buenos Aires National Wildlife 
Refuge, pers. comm. 1997; Terry Myers, Apache-Sitgreaves National 
Forest, pers. comm. 1997; Sredl et al. 1997; Rosen et al. 1996; Snyder 
et al. 1996; C. Schwalbe, University of Arizona, pers. comm. 1995; R. 
Zweifel, Portal, Arizona, pers. comm. 1995; Hale 1992; Clarkson and 
Rorabaugh 1989; Fish and Wildlife Service files, Phoenix, Arizona). In 
New Mexico, the species was either collected or observed at 170 
localities (Jennings 1995; Randy Jennings, Western New Mexico 
University, pers. comm. 1999; Charles Painter, New Mexico Game and Fish 
Department, pers. comm. 1999). Eleven historical localities were listed 
by Platz and Mecham (1979) in Mexico, mostly from the eastern base and 
foothills of the Sierra Madre Occidental in Chihuahua and Durango, and 
one site in northern Sonora, Mexico. Hillis et al. (1983) list another 
locality from Durango. However, the presence of Chiricahua leopard 
frogs in the Sierra Madre Occidental of southern Chihuahua was 
questioned by Webb and Baker (1984). Frogs at a locality on the Sonora-
Chihuahua border have been tentatively identified as Chiricahua leopard 
frogs (Holycross 1998). Some museums still have many southwestern 
leopard frogs catalogued as Rana pipiens. Once these specimens have 
been reexamined, additional historical localities for Rana 
chiricahuensis may result. Also, frogs observed at some localities, 
which may have been Rana chiricahuensis, were not positively 
    Many collections of Chiricahua leopard frogs were made before 1980 
(Jennings 1995; Platz and Mecham 1979; Frost and Bagnara 1977; Mecham 
1968). Recent surveys to document the status and distribution of the 
species were conducted primarily from the mid-1980's to the present 
(Sredl et al. 1997, 1995, 1994, 1993; Rosen et al. 1996; Fernandez and 
Bagnara 1995; Jennings 1995; Rorabaugh et al. 1995; Rosen 1995; Zweifel 
1995; Sredl and Howland 1994, 1992; Hale 1992; Scott 1992;

[[Page 37345]]

Wood 1991; Clarkson and Rorabaugh 1989; Rosen and Schwalbe 1988). These 
surveys were summarized by Jennings (1995) for New Mexico and Sredl et 
al. (1997) for Arizona. In 1995, Jennings reported Chiricahua leopard 
frogs at 11 sites in New Mexico. An additional 16 populations have been 
found since 1995 (R. Jennings, pers. comm. 1999, C. Painter, pers. 
comm. 1999), for a total of 27. Twenty-two of these occur north of 
Interstate 10 (northern populations), and five are in the southwestern 
corner of the state (southern populations). Sredl et al. (1997) 
reported that during 1990-1997 Chiricahua leopard frogs were found at 
61 sites in southeastern Arizona (southern populations) and 15 sites in 
central and east-central Arizona (northern populations). As a means to 
make the Arizona and New Mexico status information more comparable, the 
number of sites at which Chiricahua leopard frogs were observed from 
1995 to the present in Arizona were tallied. Based on available data, 
particularly Sredl et al. (1997) and Rosen et al. (1996), Chiricahua 
leopard frogs were observed at 52 sites in Arizona from 1995 to the 
present, including 9 northern localities and 43 southern localities.
    Recent surveys of potential habitats in Arizona are more complete 
than surveys done in New Mexico. Sredl et al. (1997) conducted 656 
surveys for ranid frogs (frogs in the family Ranidae) within the range 
of the Chiricahua leopard frog in southeastern Arizona. Rosen et al. 
(1996, 1994), Hale (1992), Wood (1991), Clarkson and Rorabaugh (1989), 
and others have also surveyed wetlands in southeastern Arizona 
extensively. It is unlikely that many additional new populations will 
be found there. A greater potential exists for locating frogs at 
additional localities in Arizona's northern region. Sredl et al. (1997) 
conducted 871 surveys for ranid frogs in the range of the northern 
localities, but report that only 25 of 46 historical Chiricahua leopard 
frog localities were surveyed during 1990-1997. Unsurveyed historical 
localities are primarily located on the San Carlos and Fort Apache 
Reservations, in areas that have generally not been accessible to State 
and Federal biologists. Additional populations of Chiricahua leopard 
frogs of which we are currently unaware may occur on these tribal 
    Of the historical localities in New Mexico, 80 of 170 were not 
revisited since frogs were last collected or observed. Twenty-four of 
these unvisited sites have imprecise locality information that 
precludes locating or revisiting them. Many others are on private lands 
to which the owners have denied access to biologists (the privately 
owned Gray and Ladder ranches are notable exceptions). As in Arizona, 
potential habitat within the range of the southern populations has been 
surveyed more extensively than that of the northern populations. From 
1990-1991, Scott (1992) conducted extensive surveys of the Gray Ranch, 
which contains much of the Chiricahua leopard frog habitat in 
southwestern New Mexico. Observations from numerous other 
herpetologists were included within his reports, and cowboys and ranch 
hands were interviewed to locate potential habitats. Jennings (1995) 
surveyed other potential habitats in southwestern New Mexico outside of 
the Gray Ranch in the Peloncillo Mountains. Other herpetologists 
working in that area, including Charles Painter (pers. comm. 1998) and 
Andy Holycross, Arizona State University (pers. comm. 1997), also 
worked extensively in this area. Probably few if any unknown 
populations of Chiricahua leopard frogs occur in southwestern New 
    Surveys in the northern portion of the species' range in New Mexico 
have been less complete. Jennings (1995) believed that the wilderness 
areas of the Gila National Forest have the greatest potential for 
supporting additional extant populations and for securing an intact 
metapopulation that would have a good chance of long-term persistence.
    In Mexico systematic or intensive surveys for Chiricahua leopard 
frogs were not conducted. However, it is expected that the species 
almost certainly occurs or occurred at more than the 12 (or 13) 
reported localities in Chihuahua, Sonora, and Durango (Platz and Mecham 
1979, Hillis et al. 1983, and Holycross 1998). However, the identity of 
leopard frogs in southern Chihuahua (and perhaps Durango) is in some 
question (Webb and Baker 1984). Only one locality has been documented 
in Sonora, yet populations occur or occurred in the mountain ranges and 
valleys adjacent to the Sonora border in Arizona. Other localities 
probably occur or occurred in Sonora.
    The Chiricahua leopard frog is reported absent from a majority of 
historical localities. In Arizona, Clarkson and Rorabaugh (1989) found 
the species at only 2 of 36 sites that supported Chiricahua leopard 
frogs in the 1960s and 1970s. In New Mexico, Jennings (1995) found 
Chiricahua leopard frogs at 6 of 33 sites supporting the species during 
the previous 11 years. Sredl and Howland (1994) reported finding 
Chiricahua leopard frogs at only 12 of 87 historical sites. In 1994, 
during surveys of 175 wetland sites in southeastern Arizona, Rosen et 
al. (1994) reported the Chiricahua leopard frog was extant at 19 
historical and new sites, but was not found at 32 historical 
localities. Throughout Arizona, Sredl et al. (1997) found the species 
present at 21 of 109 historical localities.
    Determining whether a species is declining based on its presence or 
absence at historical sites is difficult. Where frogs are observed at a 
particular site, they are considered extant. However, a failure to find 
frogs does not necessarily indicate the species is absent. Corn (1994) 
notes that leopard frogs may be difficult to detect, museum records do 
not always represent breeding localities, collections have occurred 
from marginal habitat, and museum and literature records often 
represent surveys over long periods of time, which ignores natural 
processes of geographical extinction and recolonization. The natural 
processes of extinction and recolonization may be particularly 
important for the Chiricahua leopard frog because its habitats are 
often small and very dynamic. Because the Chiricahua leopard frog and 
other southwestern leopard frogs exhibit a life history that 
predisposes them to high rates of extirpation and recolonization (Sredl 
and Howland 1994), its absence from at least some historical sites is 
    The failure of experienced observers to find frogs indicates that 
frogs are probably absent, particularly in relatively simple aquatic 
systems such as most stock tanks and stream segments. Howland et al. 
(1997) evaluated visual encounter surveys at five leopard frog 
localities. At sites with known populations that were not dry, frogs 
were detected in 93 of 100 surveys conducted during the day from April 
through October. During a drought in 1994, Rosen et al. (1996, 1994) 
surveyed all known localities of the Chiricahua leopard frog in 
southeastern Arizona and other accessible waters, and discussed 
locations of waters and faunal occurrence with landowners. By focusing 
on aquatic sites that did not go dry, and through careful and often 
multiple surveys at each site, the authors were able to define 
distribution at a time when aquatic faunal patterns were clear. The 
authors believed that nearly all potential habitat was surveyed, and, 
if frogs were present, they would be detectable at most sites.
    Although survey data strongly suggest that the species is absent at 
a high percentage of historical sites (absent from 76 and 82 percent of 
historical sites in New Mexico and Arizona, respectively) (Sredl et al. 
1997, Jennings

[[Page 37346]]

1995), additional analyses are warranted to determine whether 
extirpations represent natural fluctuations or long-term declines 
caused by human impacts (Blaustein et al. 1994, Pechman et al. 1991).
    Numerous studies indicate that declines and extirpations of 
Chiricahua leopard frogs are at least in part caused by predation and 
possibly competition by nonnative organisms, including fish in the 
family Centrarchidae (Micropterus spp., Lepomis spp.), bullfrogs (Rana 
catesbeiana), tiger salamanders (Ambystoma tigrinum mavortium), 
crayfish (Oronectes virilis and possibly others), and several other 
species of fish (Fernandez and Rosen 1998, Rosen et al. 1996, 1994; 
Snyder et al. 1996; Fernandez and Bagnara 1995; Sredl and Howland 1994; 
Clarkson and Rorabaugh 1989). For instance, in the Chiricahua region of 
southeastern Arizona, Rosen et al. (1996) found that almost all 
perennial waters investigated that lacked introduced predatory 
vertebrates supported Chiricahua leopard frogs. All waters except three 
that supported introduced vertebrate predators lacked Chiricahua 
leopard frogs. The authors noted an alarming expansion of nonnative 
predatory vertebrates over the last 2 decades. In the Chiricahua 
region, Chiricahua leopard frogs were primarily limited to habitats 
subject to drying or near drying, such as stock tanks, which 
discourages the establishment of nonnative predatory fish and 
bullfrogs. These habitats are highly dynamic and may be marginal 
habitats for leopard frogs (Rosen et al. 1994).
    Additional evidence that the observed absence of Chiricahua leopard 
frogs from historical sites is not the result of a natural phenomenon 
emerges from the analyses of regional occurrence. If the extirpation of 
the Chiricahua leopard frog were a natural artifact of metapopulation 
dynamics or other population-level processes, then an observer would 
not expect to find the species absent from large portions of its range. 
Rather, Chiricahua leopard frogs might be absent from some historical 
sites, but would still be found at other new or historical sites in the 
region. In New Mexico, Jennings (1995) reported extant Chiricahua 
leopard frog populations in each of the six major drainages where the 
species was found historically (Tularosa/San Francisco, Mimbres, 
Alamosa/Seco/Rio Grande, Gila, Playas, and Yaqui). However, all six are 
characterized by few, mostly small, isolated populations. Populations 
in the Playas drainage are limited to two livestock tanks. The species 
was not found on the mainstem, Middle Fork, and East Fork of the Gila 
River, where the species occurred historically at many localities.
    In Arizona, the species is still extant in all major drainages of 
historical occurrence (Little Colorado, Salt, Verde, Gila, San Pedro, 
Santa Cruz, Yaqui/Bavispe, and Magdalena river drainages), but was not 
found recently in some major tributaries and/or from river mainstems. 
For instance, the species was not reported from 1995 to the present 
from the following drainages or river mainstems where it historically 
occurred: White River, East Clear Creek, West Clear Creek, Silver 
Creek, Tonto Creek, Verde River mainstem, San Francisco River, San 
Carlos River, upper San Pedro River mainstem, Santa Cruz River 
mainstem, Aravaipa Creek, Babocomari River mainstem, and Sonoita Creek. 
In southeastern Arizona, no recent records (1995 to the present) exist 
for the following mountain ranges or valleys: Pinaleno Mountains, 
Peloncillo Mountains, Sulphur Springs Valley, Huachuca Mountains, and 
Canelo Hills. In many of these regions, Chiricahua leopard frogs were 
not found for a decade or more despite repeated surveys.
    These apparent regional extirpations provide further evidence that 
the species is disappearing from its range. Once extirpated from a 
region, natural recolonization of suitable habitats is unlikely to 
occur in the near future. Where the species is still extant, sometimes 
several small populations are found in close proximity suggesting 
metapopulations are important for preventing regional extirpation 
(Sredl et al. 1997).
    Disruption of metapopulation dynamics is likely an important factor 
in regional loss of populations (Sredl et al. 1997, Sredl and Howland 
1994). Chiricahua leopard frog populations are often small, and 
habitats are dynamic, resulting in a relatively low probability of 
long-term population persistence. However, if populations are 
relatively close together and numerous, extirpated sites can be 
    Human disturbances can result in increased rates of extinction and 
decreased rates of recolonization. If the extinction rate for a given 
population exceeds the colonization rate, that population will go 
extinct (Hanski 1991). Various human impacts (see Summary of Factors 
Affecting the Species) can result in increased extinction rates and/or 
increased isolation of populations within a metapopulation with 
resulting decreased colonization rates. In addition, big rivers, lakes, 
and reservoirs that once probably supported large populations of 
Chiricahua leopard frogs, and were likely stable source populations for 
dispersal to smaller sites, are almost all inhabited by nonnative 
predators and are unsuitable as habitat for this species (Sredl et al. 
1997, Sredl and Howland 1994). The currently extant smaller populations 
almost certainly exhibit greater extinction rates than these larger 
populations did historically.
    Rosen et al. (1996) hypothesized that ``the ongoing restriction of 
Chiricahua leopard frogs to shallow, marginal habitat types means that 
eventually the species will be wiped out by a drought (see Fellers and 
Drost 1993, Corn and Fogelman 1984) that it would readily have 
weathered in refugia now pre-empted by nonnative species. Our 
hypothesis clearly predicts that this species will go extinct in 
southern Arizona, and probably elsewhere, unless appropriate action is 
taken.'' In New Mexico, Painter (1996) reported similar findings: 
``Rana chiricahuensis is rapidly disappearing from southwest New Mexico 
(Jennings 1995, pers. obs.). Unless these unexplainable trends are 
quickly reversed, I expect the species to be extirpated from 90-100 
percent of its former range in New Mexico within the next decade * * 

Previous Federal Action

    Based on status information indicating the species was recently 
extirpated from historical localities (Clarkson and Rorabaugh 1989), 
the Chiricahua leopard frog was added to the list of category 2 
candidate species with the publication of a comprehensive Notice of 
Review on November 21, 1991 (56 FR 58804). We also included the species 
as a category 2 candidate in the November 15, 1994, Notice of Review 
(59 FR 58982). Category 2 candidates were those taxa for which we had 
some evidence of vulnerability and threats, but for which we lacked 
sufficient data to support a listing proposal.
    Beginning with our February 28, 1996, candidate notice of review 
(61 FR 7596), we discontinued the designation of multiple categories of 
candidates, and only those taxa meeting the definition for former 
category 1 candidates are now considered candidates for listing 
purposes. Category 1 candidates were taxa for which we had on file 
sufficient information on biological vulnerability and threats to 
support proposals to list them as endangered or threatened, but for 
which preparation of listing proposals was precluded by higher priority 
listing actions. In the February 28, 1996, notice, we identified the 
Chiricahua leopard frog as a candidate species.

[[Page 37347]]

    On June 10, 1998, we received a petition dated June 4, 1998, from 
the Southwest Center for Biological Diversity to list the Chiricahua 
leopard frog as endangered and to designate critical habitat for the 
species. In a letter dated July 7, 1998, we informed the petitioner 
that, pursuant to the Service's July 1996 Petition Management Guidance, 
we consider candidate species to be under petition and covered by a 
``warranted but precluded'' finding under section 4(b)(3)(B)(iii) of 
the Act. Because listing of candidates is, by definition, already 
warranted, petitions on candidates are redundant. Accordingly, we do 
not prepare 90-day findings for petitioned candidate species. We 
address the resolution of the conservation status of the Chiricahua 
leopard frog and other candidates through the Listing Priority 
    The processing of this proposed rule conforms with the Fiscal Year 
2000 Listing Priority Guidance, published 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 its 
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 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. This proposed rule is a Priority 3 action and is being 
completed in accordance with the current Listing Priority Guidance.

Peer Review

    In accordance with the policy promulgated July 1, 1994 (59 FR 
34270), we will solicit the expert opinions of at least three 
appropriate and independent specialists regarding this proposed rule. 
The purpose of such review is to ensure listing decisions are based on 
scientifically sound data, assumptions, and analyses, including input 
of appropriate experts and specialists. Peer reviewers will be mailed 
copies of this proposed rule to list the Chiricahua leopard frog as a 
threatened species immediately following publication in the Federal 
Register. We solicit peer reviewers to comment during the public 
comment period upon the specific assumptions and conclusions regarding 
this proposed listing. In the preparation of the final rule, we 
consider all comments received.

Summary of Factors Affecting the Species

    Section 4 of the Act and regulations (50 CFR part 424) promulgated 
to implement the listing provisions of the Act set forth the procedures 
for adding species to the Federal lists. A species may be determined to 
be an endangered or threatened species due to one or more of the five 
factors described in Section 4(a)(1). These factors and their 
application to the Chiricahua leopard frog (Rana chiricahuensis Platz 
and Mecham) are as follows:
    A. The present or threatened destruction, modification, or 
curtailment of its habitat or range. Riparian (in or associated with 
wetted areas) and wetland communities throughout the range of the 
Chiricahua leopard frog are much altered and/or reduced in size 
compared to early-to mid-19th century conditions (Arizona Department of 
Water Resources 1994; Brown 1985; Hendrickson and Minckley 1984; 
Minckley and Brown 1982). Dams, diversions, groundwater pumping, 
introduction of nonnative organisms, woodcutting, mining, urban and 
agricultural development, road construction, overgrazing, and altered 
fire regimes all contributed to reduced quality and quantity of 
riparian and wetland habitat (Belsky and Blumenthal 1997; Wang et al. 
1997; DeBano and Neary 1996; Bahre 1995; Brown 1985; Hadley and 
Sheridan 1995; Ohmart 1995; Stebbins and Cohen 1995; Hendrickson and 
Minckley 1984; Arizona State University 1979; Gifford and Hawkins 
    Many of these changes began before ranid frogs were widely 
collected or studied in Arizona and New Mexico. The Chiricahua leopard 
frog may have been much more widely distributed in pre-settlement times 
than is indicated by historical collections. Extant localities are 
generally located in stream and river drainage headwaters, springs, and 
stock tanks. However, historical records exist for the Verde, San 
Pedro, Santa Cruz, Mimbres, and Gila Rivers, and the species is extant 
in the mainstem of the San Francisco River in New Mexico and on the 
Blue River in Arizona. These findings suggest that it may have occurred 
in other major drainages, such as the mainstems of the Salt, White, 
Black, and Little Colorado Rivers. Habitat degradation, diversions, 
loss or alteration of stream flows, groundwater pumping, introduction 
of nonnative organisms, and other changes are often most apparent on 
these larger drainages (Sredl et al. 1997, State of Arizona 1990).
    Although the cumulative effect of such changes to its habitat is 
unknown, the extirpation of the Chiricahua leopard frog may have 
occurred in some major drainages prior to its occurrence being 
documented. These large drainages connect many of the extant and 
historical populations and may have served as important corridors for 
exchange of genetic material and as a source of frogs for 
recolonization if extirpations occurred within populations (Sredl et 
al. 1997, Rosen et al. 1996).
    Beavers (Castor canadensis) likely promoted the creation of 
Chiricahua leopard frog habitat. The activities of beavers tend to 
inhibit erosion and downcutting of stream channels (Parker et al. 
1985), and ponded water behind beaver dams is favored habitat for ranid 
frogs. However, beavers were extirpated from some areas by the late 
1800s and are still not abundant or are extirpated from other areas 
where they were once common (Hoffmeister 1986). For example, in Arizona 
beavers are extirpated from the Santa Cruz River and, before recent 
reintroductions, were extirpated from the San Pedro River. Loss of this 
large mammal and the dams it constructed likely resulted in loss of 
backwater and pool habitat favored by the Chiricahua leopard frog.
    These changes occurred before leopard frogs were widely collected; 
thus, hypotheses concerning correlations between extirpations of beaver 
and Chiricahua leopard frogs cannot be tested by comparing historical 
versus extant frog populations. Where beavers occur within the range of 
the Chiricahua leopard frog today, beaver ponds are often inhabited by 
nonnative predators, such as introduced fish and bullfrogs, that prey 
upon and likely preclude colonization by Chiricahua leopard frogs. 
Because nonnative species often thrive in beaver ponds, the presence of 
beavers could actually hinder recovery of the Chiricahua leopard frog 
in some systems.
    Stock tanks, constructed as water sources for livestock, are very 
important habitats for the Chiricahua leopard frog throughout its 
range. In some areas, stock tanks replaced natural springs and cienegas 
and provide the only suitable habitat available to the Chiricahua 
leopard frog. For instance, the only known localities of the Chiricahua 
leopard frog in the San Rafael and San Bernardino Valleys, Fossil Creek 
drainage, and in the Patagonia Mountains of Arizona are stock tanks. 
Sixty-one percent of extant Chiricahua leopard frog localities in 
Arizona are stock tanks, versus only 35 percent of extirpated 
localities (Sredl and Saylor

[[Page 37348]]

1998), suggesting Arizona populations of this species have fared better 
in stock tanks than in natural habitats. However, this generalization 
may not be true for New Mexico, where in recent years many stock tank 
populations were extirpated. Sredl and Saylor (1998) also found that 
stock tanks are occupied less frequently by nonnative predators (with 
the exception of bullfrogs) than natural sites. Therefore, a high 
probability exists that the Chiricahua leopard frog would be extirpated 
from many more areas if ranchers had not built and maintained stock 
tanks for livestock production.
    Although stock tanks provide refugia for frog populations and are 
very important for this species, only small populations are supported 
by such tanks, and these habitats are very dynamic. Tanks often dry out 
during drought, and flooding may destroy downstream impoundments or 
cause siltation, either of which may result in loss of aquatic habitat 
and extirpation of frog populations. Periodic maintenance to remove 
silt from tanks may also cause a temporary loss of habitat. Populations 
of nonnative introduced predaceous fish and bullfrogs, although less 
prevalent than in natural habitats, sometimes become established in 
stock tanks and are implicated in the decline of the Chiricahua leopard 
frog (Rosen et al. 1996, 1994). Stock tanks may facilitate spread of 
nonnative organisms by providing aquatic habitats in arid landscapes 
that otherwise may have served as barriers to the spread of such 
organisms. In New Mexico, stock tank populations in some areas were 
eliminated by disease (Declining Amphibian Populations Task Force 
    Grazing by domestic livestock occurs throughout the range of the 
Chiricahua leopard frog. The effects of livestock grazing on leopard 
frog populations are not well studied. As discussed, construction of 
tanks for livestock has created important leopard frog habitat, and in 
some cases has replaced destroyed or altered natural wetland habitats. 
A large and healthy population of Chiricahua leopard frogs coexists 
with cattle and horses on the Tularosa River, New Mexico (Randy 
Jennings, Western New Mexico University, pers. comm. 1995).
    Maintenance of viable populations of Chiricahua leopard frogs is 
thought to be compatible with well-managed livestock grazing. However, 
adverse effects to the species and its habitat may occur under certain 
circumstances. These effects to habitats include deterioration of 
watersheds, erosion and/or siltation of stream courses, elimination of 
undercut banks that provide cover for frogs, and loss of wetland and 
riparian vegetation and backwater pools (Belsky et al. 1999, Ohmart 
1995; Hendrickson and Minckley 1984; Arizona State University 1979). 
Eggs and tadpoles of the Chiricahua leopard frog are probably trampled 
by cattle on the perimeter of stock tanks and in pools along streams. 
Cattle can also contribute to degraded water quality at stock tanks, 
including elevated hydrogen sulfide concentrations, which are toxic to 
frogs (Sredl et al. 1997).
    Many large impoundments or lakes were created within the range of 
the Chiricahua leopard frog for water storage, recreation, and as a 
source of hydroelectric power. Historical records exist for the species 
from Luna Lake, Nelson Reservoir, Hawley Lake, and Rainbow Lake north 
of the Gila River in Arizona; and Lake Roberts, Patterson Lake, and Ben 
Lilly Lake in New Mexico, but surveys at these sites since 1985 located 
no frogs (Jennings 1995, Arizona Game and Fish Department (AGFD) 1997). 
Currently, large impoundments invariably support populations of 
nonnative fish and/or bullfrogs. Predation and possibly competition 
with leopard frogs by these introduced predators likely contributed to 
the disappearance of the Chiricahua leopard frog from reservoir 
    Construction and operation of reservoirs also alter downstream 
flows and can result in dramatic changes in stream hydrology, rates of 
erosion and sedimentation, riparian vegetation, and other components of 
riparian ecosystems (Johnson 1978). The effects of these changes on 
Chiricahua leopard frog populations are unknown. However, downstream 
effects of such impoundments are implicated in the decline of other 
anurans (frogs and toads), including the endangered arroyo toad (Bufo 
californicus) (Service 1993) and the foothill yellow-legged frog (Rana 
boylii) (Lind et al. 1996).
    On the Trinity River in California, the extent of riparian 
vegetation increased with an accompanying decrease in sandbar habitat, 
of which the latter was breeding habitat of the yellow-legged frog. 
Unseasonably high flows from dam releases also resulted in loss of 
entire cohorts or age groups of larval frogs (Lind et al. 1996). 
Similar effects may occur in Chiricahua leopard frog habitat. Water 
temperatures are often colder below dams than in similar unaltered 
systems (Lind et al. 1996), which may retard development of frog eggs 
and larvae (Stebbins and Cohen 1995). Lack of scouring flood flows 
below dams may also create relatively stable pool habitat with 
established vegetation that favors establishment of bullfrogs (Lind et 
al. 1996). Dispersal of nonnative fish from impoundments to either 
downstream or upstream reaches may have resulted in further adverse 
effects to frog populations.
    Only a few extant or historical Chiricahua leopard frog localities 
are thought to be directly affected by current mining operations. 
Active mining occurs in California Gulch, Pajarito Mountains, Arizona, 
but is limited to a short reach of the drainage. The recently proposed 
Gentry Iron Mine may be located within 1.6 km (1.0 mi) of two 
Chiricahua leopard frog populations on the Tonto National Forest, 
Arizona. The resulting effects of the proposed mining activities on 
these populations are uncertain at this time, but may include changes 
in water quality and flow rates. Populations of Chiricahua leopard frog 
northeast of Hurley, Grant County, New Mexico, may also be affected by 
mining. Evidence of mining can be found at or near many other 
localities, but few mines are currently active and most do not directly 
affect the wetland and riparian habitats occupied by the species. 
Although mining activities were more widespread historically and may 
have constituted a greater threat in the past, the mining of sand and 
gravel, iron, gold, copper, or other materials remains a potential 
threat to the habitat of the Chiricahua leopard frog. In addition, as 
noted in Factor C of this section, mining also has indirect adverse 
effects to this species.
    Fire frequency and intensity in the mountain ranges of southeastern 
Arizona and southwestern New Mexico are much altered from historic 
conditions. Before 1900, surface fires generally occurred at least once 
per decade in montane forests with a pine component. Beginning about 
1870-1900, these frequent ground fires ceased to occur due to intensive 
livestock grazing that removed fine fuels, followed by effective fire 
suppression in the mid to late 20th century (Swetnam and Baisan 1996). 
Absence of ground fires allowed a buildup of woody fuels that 
precipitated infrequent but intense crown fires (Danzer et al. 1997, 
Swetnam and Baisan 1996). Absence of vegetation and forest litter 
following intense crown fires exposes soils to surface and rill erosion 
during storms, often causing high peak flows, sedimentation, and 
erosion in downstream drainages (DeBano and Neary 1996). Following the 
1994 Rattlesnake fire in the Chiricahua Mountains, Arizona, a debris 
flow filled in Rucker Lake, a historic Chiricahua leopard frog 
locality. Leopard frogs

[[Page 37349]]

(either Chiricahua or Ramsey Canyon leopard frogs) apparently 
disappeared from Miller Canyon in the Huachuca Mountains, Arizona, 
after a 1977 crown fire in the upper canyon and subsequent erosion and 
scouring of the canyon during storm events (Tom Beatty, Miller Canyon, 
pers. comm. 2000). Leopard frogs were historically known from many 
localities in the Huachuca Mountains; however, natural pool and pond 
habitat is largely absent now, and the only breeding leopard frog 
populations occur in man-made tanks and ponds. Bowers and McLaughlin 
(1994) list six riparian plant species they believed might have been 
eliminated from the Huachuca Mountains as a result of floods and debris 
flow following destructive fires.
    Other activities have also affected the habitat of the Chiricahua 
leopard frog. For instance, in an attempt to increase flow, explosives 
were used at Birch Springs in the Animas Mountains to open up the 
spring. The explosion resulted in destruction of aquatic habitat, flows 
were reduced rather than increased, and Chiricahua leopard frogs 
subsequently disappeared (N. Scott, pers. comm. 1994).
    B. Overutilization for commercial, recreational, scientific, or 
educational purposes. The collection of Chiricahua leopard frogs in 
Arizona is prohibited by Arizona Game and Fish Commission Order 41, 
except where such collection is authorized by special permit. 
Collection of Chiricahua leopard frogs is also prohibited in Mexico. 
The collection of Chiricahua leopard frogs is not prohibited in the 
State of New Mexico.
    Over-collection for commercial purposes is known to be a 
contributing factor in the decline of other ranid frogs (Jennings and 
Hayes 1985, Corn and Fogelman 1984). Although collection is not 
documented as a cause of population decline or loss in the Chiricahua 
leopard frog, the collection of large adult frogs for food, scientific, 
or other purposes, particularly after a winter die-off or other event 
that severely reduces the adult population, can hasten the extirpation 
of small populations. The listing of the Chiricahua leopard frog and 
its recognition as a rare species is reasonably expected to increase 
its value to collectors. In 1995, many large adult Ramsey Canyon 
leopard frogs (closely related to the Chiricahua leopard frog) were 
illegally collected from a site in the Huachuca Mountains, Arizona, 
following publicity about the rare status of the frog.
    C. Disease or predation. Predation by introduced, nonnative 
bullfrogs and fish was implicated as a contributing factor in the 
decline of ranid frogs in western North America (Bradford et al. 1993, 
Hayes and Jennings 1986, Moyle 1973), and may be the most important 
factor identified so far in the current decline of the Chiricahua 
leopard frog (Rosen et al. 1994, 1996). In southeastern Arizona, Rosen 
et al. (1994, 1996) documented 13 nonnative predaceous vertebrate 
species in aquatic habitats in the range of the Chiricahua leopard 
frog, including bullfrog, tiger salamander, and 11 fish species 
including bass, trout, and catfish, among others.
    Rosen et al. (1994, 1996) found that Chiricahua leopard frogs were 
replaced by bullfrogs and centrarchid fish. Sixteen of 19 localities 
where Chiricahua leopard frogs occurred lacked nonnative vertebrates. 
All historical frog localities that lacked Chiricahua leopard frogs 
supported nonnative vertebrates. At the three sites where Chiricahua 
leopard frogs occurred with nonnatives (one site with green sunfish, 
Lepomis cyanellus, and two with tiger salamanders), either the frog or 
the nonnative vertebrate was rare. In two of the three cases, frogs may 
have derived from other nearby localities (Rosen et al. 1996), and thus 
may have represented immigrants rather than a viable population.
    In the San Rafael Valley, Arizona, Chiricahua leopard frogs were 
found only at sites that lacked nonnative fish and bullfrogs (Snyder et 
al. 1996). In the White Mountains of Arizona, disappearance of 
Chiricahua leopard frogs from most historical localities correlated 
with the appearance of tiger salamanders and nonnative crayfish 
(Fernandez and Bagnara 1995). Crayfish were found to prey upon 
Chiricahua leopard frog larvae, metamorphs, and adults. Crayfish 
recently spread to the breeding pond of one of the last and possibly 
the most robust populations of Chiricahua leopard frogs in the White 
Mountains, Arizona (M. Sredl, pers. comm. 1999, Fernandez and Rosen 
    Sredl and Howland (1994) noted that Chiricahua leopard frogs were 
nearly always absent from sites supporting bullfrogs and nonnative 
predatory fish; however, Rosen et al. (1996) suggested further study 
was needed to evaluate the effects of mosquitofish, trout, and catfish 
on frog presence. Rosen et al. (1996) suspected that catfish would 
almost always exclude Chiricahua leopard frogs, and that trout may 
exclude leopard frogs.
    In contrast to nonnative aquatic vertebrates, numerous species of 
native fish, the Sonoran mud turtle (Kinosternon sonoriense), other 
species of native ranid frogs, and native garter snakes (Rosen et al. 
1996, Platz and Mecham 1979) commonly coexist with the Chiricahua 
leopard frog. Tiger salamanders are native to the following portions of 
the Chiricahua leopard frog's range: San Rafael Valley in southeastern 
Arizona (Ambystoma tigrinum stebbinsi), the northern portion of the 
species' range (Ambystoma tigrinum nebulosum), and the mountains of 
Sonora, Chihuahua, and Durango (Ambystoma rosaceum). Native fishes, 
such as trout (Oncorhynchus), chub (Gila), and topminnow 
(Poeciliopsis), also occur within the range of the Chiricahua leopard 
    The Rio Grande leopard frog (Rana berlandieri) is a recent 
introduction to southwestern Arizona, (Platz et al. 1990). Although the 
species does not presently occur within the range of the Chiricahua 
leopard frog, the Rio Grandes leopard frog is rapidly expanding its 
distribution and currently occurs as far east as the Phoenix area 
(Rorabaugh et al. in prep.). If it continues to spread eastward, the 
ranges of the Rio Grande and Chiricahua leopard frogs may overlap in 
the future. This large, introduced leopard frog might prey on small 
Chiricahua leopard frogs (Platz et al. 1990), and tadpoles of the two 
species may compete.
    In June 1994, a die-off of Chiricahua leopard frogs occurred at a 
stock tank in the Chiricahua Mountains, Arizona, that reduced the frog 
population from 60-80 adults to fewer than 10 (Sredl et al. 1997). 
Analysis of dead and moribund frogs and water from the tank indicated 
that disease was unlikely to be the cause of the die-off, however, 
levels of hydrogen sulfide were high enough to be toxic to wildlife. 
The authors suspected that high detritus loads (including cattle 
feces), low water levels, high water temperature, and low 
concentrations of dissolved oxygen created a suitable environment for 
sulphur-producing bacteria that produced toxic levels of hydrogen 
sulfide. Chiricahua leopard frogs were not found at this site in 1998.
    The disease Postmetamorphic Death Syndrome (PDS) was implicated in 
the extirpation of Chiricahua leopard frog populations in Grant County, 
New Mexico, as well as in other frog and toad species (Declining 
Amphibian Populations Task Force 1993). All stock tank populations of 
the Chiricahua leopard frog in the vicinity of Gillette and Cooney 
tanks in Grant County disappeared within a 3-year period, apparently as 
a result of PDS (Declining Amphibian Populations Task Force 1993). The 
syndrome is characterized by death of all or most recently 
metamorphosed frogs in a short period

[[Page 37350]]

of time. Dead or moribund frogs are often found during or immediately 
following winter dormancy or unusually cold periods. The syndrome 
appears to spread among adjacent populations causing regional loss of 
populations or metapopulations. Evidence suggests that PDS may also be 
present in the Santa Rita and Pajarito mountains, Arizona. Although 
winter die-offs are not documented, Steve Hale (Tucson, AZ, pers. comm. 
1994) observed very few Chiricahua leopard frogs in the spring, 
suggesting that frogs are dying during the winter months. The apparent 
post-metamorphic death of the Tarahumara frog was documented in 
southern Arizona and northern Sonora (Hale et al. 1995, Hale and 
Jarchow 1988), and numbers of Ramsey Canyon leopard frogs declined in 
the Huachuca Mountains, Arizona, during the winters of 1997-1998 and 
    Arsenic poisoning may be a contributing factor in PDS (Hale and 
Jarchow 1988). Elevated arsenic levels may have contributed to the 
extirpation of the Tarahumara frog at a site in northern Sonora (Hale 
and Jarchow 1988). Arsenic often occurs at high levels near sulfitic 
mine tailings and may be leached by rainfall containing elevated levels 
of sulfate (Hale and Jarchow 1988). Rainfall near Elgin in southeastern 
Arizona contained high levels of sulfate, probably due to emissions 
from copper smelters in Cananea and Nacozari, Sonora, and Douglas, 
Arizona (Blanchard and Stromberg 1987). The smelters at Cananea and 
Douglas are no longer in operation.
    The size of the Chiricahua leopard frog population in Sycamore 
Canyon in the Pajarito Mountains of Arizona appears to vary greatly 
from year to year. This annual variation in population size may be 
attributable, in part, to cadmium toxicity (Hale and Jarchow 1988). A 
likely source of cadmium in Chiricahua leopard frog habitat is 
emissions from copper smelters at Cananea and Nacozari, Sonora (Hale 
and Jarchow 1988, Blanchard and Stromberg 1987). Elevated levels of 
cadmium also occur in and near tailings of copper, lead, and zinc mines 
(Peterson and Alloway 1979). Cadmium may be mobilized and deposited 
into stream courses through rainfall.
    From 1980 to 1985, Chiricahua leopard frogs were abundant in 
Sycamore Canyon only at Hank and Yank Tank and in the creek immediately 
downstream of it. In May 1982 the ratio of zinc to cadmium in this 
reach was 5 to 30 times that of downstream reaches where frogs were 
absent or very rare (Hale and Jarchow 1988). Cumulative leaching and 
deposition in drainages likely results in elevated concentrations of 
cadmium in downstream reaches. Thus, stream headwaters and springs, 
such as Hank and Yank Tank, may be important refugia for frogs during 
times when toxic conditions exist in downstream reaches. Decreased zinc 
to cadmium ratios may have also contributed to the extirpation of the 
Tarahumara frog from one site in southern Arizona and three sites in 
northern Sonora (Hale and Jarchow 1988).
    Other contaminants or pathogens may also be contributing to the 
decline of the Chiricahua leopard frog. Lips (1998) documented reduced 
abundance and skewed sex ratios of two anuran species, and dead and 
dying individuals of six other amphibian species in Puntarenas 
Province, Costa Rica. She attributed these changes to biotic pathogens 
or chemicals, or the combined effects of environmental contamination 
and climate change. Toxic agrochemicals may have been transported via 
winds and the atmosphere over long distances to the remote sites 
studied in Costa Rica. Her observations are also consistent with a 
pathogen outbreak, and recent evidence suggests a chytridiomycete skin 
fungi may be responsible for the declines (Longcore et al. 1999, Berger 
et al. 1998). Lips (1998) noted that declines in her study area are 
similar to those reported for Monteverde, Costa Rica, the Atlantic 
coast of Brazil, and Australia. Amphibian decline in these areas has 
spread wave-like across the landscape, suggestive of pathogen 
dispersal. Chytrid fungi have recently been shown to be associated with 
amphibian declines in Panama and Queensland, Australia (Berger et al. 
1998); the authors hypothesize that it is the proximate cause of 
amphibian decline in these areas. Chytrid fungi have also been found in 
captive arroyo toads, Bufo californicus, in California, cricket frogs, 
Acris crepitans, in Illinois, American toads, Bufo americanus, in 
Maryland, and in Arizona, lowland leopard frogs, Rana yavapaiensis, Rio 
Grande leopard frogs, Ramsey Canyon leopard frogs, and four populations 
of Chiricahua leopard frogs (M. Sredl, pers. Comm., 2000; Milius 1998). 
The role of the fungi in the population dynamics of the Chiricahua 
leopard frog and these other North American species is as yet 
undefined; however, it may well prove to be an important contributing 
factor in observed population decline. Rapid death of recently 
metamorphosed frogs, typical of post-metamorphic death syndrome, is 
also characteristic of chytrid infections. Thus, chytrids may have 
played a role in extirpation of stock tank populations of Chiricahua 
leopard frog in New Mexico (Declining Amphibian Populations Task Force 
1993), as well as overwinter die-offs in the mountains of southern 
    D. The inadequacy of existing regulatory mechanisms. A variety of 
existing international conventions and law and Federal and State 
regulations provide limited protection to the Chiricahua leopard frog 
and its habitat. State regulations prohibit collection or hunting of 
Chiricahua leopard frogs in Arizona, except under special permit. 
Collection is not prohibited in New Mexico, and although collecting has 
not been documented as a cause of population loss, the typically small, 
geographically isolated populations of this species are extremely 
vulnerable to collection pressure. Regulations have not been adequate 
to stem habitat loss and degradation or to address factors such as 
introduction of nonnative predators.
    In Mexico, the collection of threatened species is prohibited. The 
habitats of the Chiricahua leopard frog and other threatened species 
are protected from some activities in Mexico. The species is not 
protected by the Convention on International Trade in Endangered 
Species of Wild Fauna and Flora, which regulates international trade.
    The Lacey Act (16 U.S.C. 3371 et seq.), as amended in 1982, 
provides some protection for the Chiricahua leopard frog. This 
legislation prohibits the import, export, sale, receipt, acquisition, 
purchase, and engagement in interstate or foreign commerce of any 
species taken, possessed, or sold in violation of any law, treaty, or 
regulation of the United States, any Tribal law, or any law or 
regulation of any State.
    The Federal Land Policy Management Act of 1976 (43 U.S.C. 1701 et 
seq.) and the National Forest Management Act of 1976 (16 U.S.C. 1600 et 
seq.) direct Federal agencies to prepare programmatic-level management 
plans to guide long-term resource management decisions. In addition, 
the Forest Service is required to ``maintain viable populations of 
existing native and desired nonnative species'' in their planning areas 
(36 CFR 219.19). These regulations have resulted in the preparation of 
a variety of land management plans by the Forest Service and the Bureau 
of Land Management that address management and resource protection of 
areas that support, or in the past supported, populations of Chiricahua 
leopard frogs.

[[Page 37351]]

    At least 47 of 79 localities confirmed as supporting extant 
populations of the Chiricahua leopard frog from 1995 to the present 
occur entirely, or in part, on National Forest Lands. Thirty-four 
extant localities occur entirely, or in part, on the Coronado National 
Forest, Arizona. Additional localities occur on the Gila, Apache-
Sitgreaves, Tonto, and Coconino National Forests. As a result, Forest 
Service land management plans are particularly important in guiding the 
management of Chiricahua leopard frog habitat. However, these plans 
have not always adequately protected this species' habitat. Many 
activities that affect the Chiricahua leopard frog and its habitat are 
beyond Forest Service control. For instance, the Forest Service does 
not have the authority to regulate off-site activities such as 
atmospheric pollution from copper smelters or other actions that may be 
responsible for global amphibian declines, including that of the 
Chiricahua leopard frog. The Forest Service has only limited ability to 
regulate introductions or stockings of nonnative species that prey on 
Chiricahua leopard frogs. Despite extensive planning efforts by the 
Forest Service and implementation of management actions to maintain 
viable populations of native species on Forest Service lands, loss of 
Chiricahua leopard frog populations and metapopulations continues.
    The National Environmental Policy Act of 1969 (NEPA) (42 U.S.C. 
4321-4370a) requires Federal agencies to consider the environmental 
impacts of their actions. NEPA requires Federal agencies to describe 
the proposed action, consider alternatives, identify and disclose 
potential environmental impacts of each alternative, and involve the 
public in the decision-making process. Federal agencies are not 
required to select the alternative having the least significant 
environmental impacts. A Federal action agency may select an action 
that will adversely affect sensitive species provided that these 
effects were known and identified in a NEPA document. Most actions 
taken by the Forest Service, the Bureau of Land Management, and other 
Federal agencies that affect the Chiricahua leopard frog are subject to 
the NEPA process.
    State and Federal air quality regulations strictly regulate 
emissions from copper smelters, a major source of atmospheric cadmium 
and arsenic, pollutants that may adversely affect the Chiricahua 
leopard frog (Hale and Jarchow 1988). However, a major source of 
airborne pollutants likely affecting this species has been copper 
smelters in Cananea and Nacozari, Sonora, which are not subject to the 
same strict regulations as in the United States (Hale et al. Blanchard 
and Stromberg 1987).
    Wetland values and water quality of aquatic sites inhabited by the 
Chiricahua leopard frog are afforded varying protection under the 
Federal Water Pollution Control Act of 1948 (33 U.S.C. 1251-1376), as 
amended, and Federal Executive Orders 11988 (Floodplain Management) and 
11990 (Protection of Wetlands). The protection afforded by these and 
other Federal laws and regulations discussed herein is inadequate to 
halt population extirpation and the degradation of the habitat of this 
    The AGFD included the Chiricahua leopard frog on their draft list 
of species of concern (AGFD 1996); however, this designation affords no 
legal protection to the species or its habitat. Collection of 
Chiricahua leopard frogs is prohibited in Arizona, except by special 
permit. The Chiricahua leopard frog is not a State-listed species, nor 
is collection prohibited in New Mexico.
    The New Mexico Department of Game and Fish adopted a wetland 
protection policy in which the Department does not endorse nor take any 
action that would promote any private or public project that would 
result in a net decrease in either wetland acreage or wetland habitat 
values. This policy affords only limited protection to Chiricahua 
leopard frog habitat because it is advisory only; destruction or 
alteration of wetlands is not regulated by State law.
    State of Arizona Executive Order Number 89-16 (Streams and Riparian 
Resources), signed on June 10, 1989, directs State agencies to evaluate 
their actions and implement changes, as appropriate, to allow for 
restoration of riparian resources. Implementation of this regulation 
may reduce adverse effects of some State actions on the habitat of the 
Chiricahua leopard frog.
    E. Other natural or manmade factors affecting its continued 
existence. Because of the inherent dynamic nature of southwestern 
wetland and riparian habitats, coupled with the increased likelihood of 
extirpation characteristic of small populations, the viability of 
extant populations of the Chiricahua leopard frog is thought, in many 
cases, to be relatively short. Approximately 38 of 79 extant localities 
found from 1995 to the present were located in artificial tanks or 
impoundments constructed for watering livestock. These environments are 
very dynamic due to flooding, drought, and human activities such as 
maintenance of stock tanks. In addition, stock tank populations are 
often quite small. Small populations are subject to extirpation from 
random variations in such factors as the demographics of age structure 
or sex ratio, and from disease and other natural events (Wilcox and 
Murphy 1985). Inbreeding depression and loss of genetic diversity may 
also occur in small populations of less than a few hundred individuals; 
such loss may reduce the fitness of individuals and the ability of the 
population to adapt to change (Frankel and Soule 1981). Both of these 
genetic considerations result in an increased likelihood of extirpation 
(Lande and Barrowclough 1987).
    The dynamic nature of stock tank habitats and the small size of the 
populations that inhabit them suggest that many of these populations 
are not likely to persist for long periods. As an example, siltation 
and drought dramatically reduced the extent of aquatic habitat at 
Rosewood Tank in the San Bernardino Valley, Arizona (Matt Magoffin, San 
Bernardino National Wildlife Refuge, pers. comm. 1997). Aquatic habitat 
was reduced in June 1994, to a surface area of approximately 60 square 
feet (sq. ft) that supported a population of approximately eight adult 
Chiricahua leopard frogs and several hundred tadpoles. In this 
instance, the landowner was only able to prevent the population from 
being extirpated by repeated efforts to intervene on behalf of the 
Chiricahua leopard frog in trucking water to the site, rebuilding the 
tank, and constructing a small permanent pond to maintain habitat for 
the species.
    Some larger populations occurring in stream courses or other non-
stock tank habitats also experience dramatic changes in population 
size, such as in Sycamore Canyon in the Pajarito Mountains, Arizona, 
and on the eastern slope of the Santa Rita Mountains, Arizona (S. Hale, 
pers. comm. 1994). These habitats, although much larger than a stock 
tank, experience dramatic environmental phenomena such as floods, 
drought, and in the case of Sycamore Canyon, varied zinc to cadmium 
ratios, all of which may cause populations to crash. This finding 
suggests that even these relatively large and natural habitats and the 
frog populations they support are very dynamic. As a result of this 
dynamic nature, leopard frog populations are susceptible to 
    As discussed in the ``Background'' section of this proposed rule, 
metapopulations are more likely to persist over time than small, more 
isolated populations, because individuals and genetic material can be 
exchanged among populations within the metapopulation, resulting in 
increased recolonization rates and fewer

[[Page 37352]]

potential genetic problems. To define metapopulations of the Chiricahua 
leopard frog, some knowledge of the ability of this species to move 
among aquatic sites is required. Although the ability of the Chiricahua 
leopard frog to move among aquatic sites needs some additional study, 
the Chiricahua leopard frog is considered a highly aquatic species 
(Stebbins 1985) that may not travel as far from water as other leopard 
frog species. Amphibians, in general, have limited dispersal and 
colonization abilities due to physiological constraints, limited 
movements, and high site fidelity (Blaustein et al. 1994). Dispersal of 
Chiricahua leopard frogs probably occurs most often along drainages, 
particularly those with permanent water, but also along intermittent 
stream courses and overland during summer rains.
    Where several populations of Chiricahua leopard frog occur in close 
proximity (separated by no more than a few kilometers), functional 
metapopulations may exist. Two areas of the Galiuro Mountains of 
Arizona support a total of 12 extant localities, including 4 localities 
in the northern end of the range and 8 in the southern end. A similar 
cluster of seven localities occurs in the Dragoon Mountains, Arizona. 
Metapopulations may exist elsewhere, for instance, in Arizona in the 
southwest quarter of the San Rafael Valley, and in the Crouch Creek 
area, and in New Mexico, east and northeast of Hurley, and in the 
Frieborn Canyon-Dry Blue Creek area. However, with the exception of 
those in the Dragoon and southern Galiuro mountains, metapopulations of 
which we are aware probably consist of five or fewer localities. 
Metapopulations, particularly the larger examples, are critical to 
long-term survival of the species. Also critical are large populations, 
such as on the Tularosa River, New Mexico, and Sycamore Canyon and 
associated tanks in the Pajarito Mountains, Arizona, which are expected 
to experience relatively low extinction rates and may serve as source 
populations for colonization of nearby suitable habitats.
    In making the determination to propose this rule, we carefully 
assessed the best scientific and commercial information available 
regarding the past, present, and future threats faced by the Chiricahua 
leopard frog. Based on this evaluation, our preferred action is to list 
the Chiricahua leopard frog as threatened. The Act defines an 
endangered species as one that is in danger of extinction throughout 
all or a significant portion of its range. The Act defines a threatened 
species as any species likely to become endangered within the 
foreseeable future.
    Within its range in the United States, the Chiricahua leopard frog 
is believed absent from a relatively high percentage of historical 
localities, and has undergone regional extirpation in areas where it 
was once well-distributed. The status of populations in Mexico are 
unknown, but the species is considered as threatened by the Mexican 
Government. The species is not in immediate danger of extinction, 
because at least a few relatively robust populations and 
metapopulations still exist (e.g., Tularosa River, Dragoon Mountains, 
Galiuro Mountains), and 79 extant localities have been documented from 
1995 to the present. However, if present threats and declines continue, 
the Chiricahua leopard frog is likely to become an endangered species 
in the foreseeable future (Painter 1996, Rosen et al. 1996). Therefore, 
we believe that the Chiricahua leopard frog meets the definition of a 
threatened species under the Act.

Critical Habitat

    Critical habitat is defined in Section 3 of the Act as--(I) the 
specific areas within the geographic area occupied by a species, at the 
time it is listed in accordance with the Act, on which are found those 
physical or biological features (I) essential to the conservation of 
the species and (II) that may require special management consideration 
or protection and; (ii) specific areas outside the geographic area 
occupied by a species at the time it is listed, upon determination that 
such areas are essential for the conservation of the species. 
``Conservation'' means the use of all methods and procedures that are 
necessary to bring an endangered species or a threatened species to the 
point at which listing under the Act is no longer necessary.
    Section 4(b)(2) and 4(b)(6)(C) of the Act, as amended, and 
implementing regulations (50 CFR 424.12) require that, to the maximum 
extent prudent and determinable, the Secretary designate critical 
habitat at the time the species is determined to be endangered or 
threatened. The designation of critical habitat is not prudent (50 CFR 
424.12(a)(1)) when one or both of the following situations exist--(1) 
the species is threatened by taking or other human activity, and 
identification of critical habitat can be expected to increase the 
degree of threat, or (2) such designation would not be beneficial to 
the species.
    Critical habitat designation would require publishing in the 
Federal Register the locations of all or the most important Chiricahua 
leopard frog populations and habitats. As discussed under Factor B in 
the ``Summary of Factors Affecting the Species,'' the Chiricahua 
leopard frog is potentially threatened by collection. Publishing 
locality data would facilitate collection as it would provide 
collectors with specific, previously unknown information about the 
location of this species. Collection has contributed to the decline of 
other rare anurans, including the endangered Wyoming toad (Bufo 
hemiophrys baxteri), threatened California red-legged frog (Rana aurora 
draytonii) (Stebbins and Cohen 1995, Jennings and Hayes 1995), and a 
number of other anuran species worldwide (Vial and Saylor 1993).
    Scientists have not documented collection, to date, as a cause of 
population decline or loss in the Chiricahua leopard frog. However, 
such collection would be difficult to document. Collection of large 
adult frogs for food, fish bait, scientific, or other purposes, 
particularly after a winter die-off or other event that severely 
reduces the adult population, could hasten the extirpation of small 
populations. Recognition of the Chiricahua leopard frog as a threatened 
species may increase its value to collectors. The Chiricahua leopard 
frog is an attractive, often bright green frog that we believe would do 
quite well in captivity. The Northern leopard frog, Rana pipiens, a 
very similar animal, is common in the pet trade. We are aware of 
internet trade in ``leopard frogs,'' which could include Chiricahua 
leopard frogs. Chiricahua leopard frogs should be as attractive as the 
Northern leopard frog to collectors, or perhaps more so because of 
their rarity.
    Import and export data provided by our Division of Law Enforcement 
document a substantial amount of international trade in Rana spp. 
Specifically, for the period of January 1, 1996, to October 31, 1998, 
9,997 live individuals of Rana spp. were imported into and 51,043 live 
individuals were exported from the United States. Because shipments of 
wildlife from the United States are not as closely monitored as 
imports, and are sometimes not recorded to the genus level (this is 
also true for imports as well), the number of exports documented for 
this timeframe is likely an under representation of what actually 
    In 1995, many large adult Ramsey Canyon leopard frogs (which are 
very similar in appearance and closely related to the Chiricahua 
leopard frog) were illegally collected from a site in the Huachuca 
Mountains, Arizona,

[[Page 37353]]

following publicity about the rare status of the frog. The locality, 
which occurs within the range of the Chiricahua leopard frog, has been 
considered extirpated since 1997. Collection probably contributed to 
its demise. Following newspaper publicity regarding our proposal to 
list the Arroyo toad (Bufo microscaphus californicus), a former U.S. 
Forest Service employee found that a main pool near the road, formerly 
with a high density of calling males, was absent of males, some 
previously tagged. The tagged males could not be located elsewhere, and 
their absence was not thought to be due to natural movement or 
predation (Nancy Sandburg, U.S. Forest Service pers. comm. 1999). 
Publishing maps for the best populations and habitats of Chiricahua 
leopard frog could cause or contribute to similar declines or 
extirpations. The evidence shows, therefore, that threat of collection 
would increase substantially if we disclosed specific location 
information for all or the most important Chiricahua leopard frog 
populations and habitats.
    Publishing locality data could also facilitate vandalism of 
habitats where Chiricahua leopard frogs occur. Platz (1995) noted the 
disappearance of large tadpoles at a Ramsey Canyon leopard frog site in 
Brown Canyon, Huachuca Mountains, in 1991-1992, and suggested their 
disappearance may have, in part, resulted from an act of vandalism. 
Many Chiricahua leopard frog habitats are small and could be easily 
contaminated with toxicants or taken over by nonnative predators, 
resulting in extirpation of frog populations. The majority of extant 
populations also occur on public lands (primarily National Forest 
lands) with public access routes that lead to the populations or pass 
nearby. Public access to these sites is reasonably expected to 
facilitate collections or vandalism.
    Publishing maps of Chiricahua leopard frog sites could also 
facilitate disease transmission. Chytridiomycosis and other amphibian 
diseases can be spread by transporting mud, water, or frogs from one 
site to another. If a person visits a site where disease is present and 
then travels to another site, disease can be spread via muddy or wet 
boots, nets, vehicles or other equipment (Speare et al. 1998, David 
Green, National Wildlife Health Center, Madison, Wisconsin, pers. comm. 
2000). Although other hypotheses have been proposed (Carey et al. 
1999), Daszak et al. (1999) find that the pattern of amphibian deaths 
and population declines associated with chytridiomycosis is consistent 
with an introduced pathogen. The chytrid fungus is not known to have an 
airborne spore, but rather disperses among individuals and populations 
via zoospores that swim through water or during contact between 
individual frogs (Daszak 1998). If chytridiomycosis is a recent 
introduction on a global scale, then dispersal by way of global or 
regional commerce; translocation of frogs and other organisms; and 
travel among areas by anglers, scientists, tourists, and others are 
viable scenarios for transmission of this disease (Daszak et al. 1999, 
Halliday 1998). Until the spread of chytridiomycosis is better 
understood, and the role of this and other diseases in the decline of 
the Chiricahua leopard frog is clarified, visitation of Chiricahua 
leopard frog sites should not be encouraged. Publishing maps of 
Chiricahua leopard frog sites could facilitate visitation by collectors 
or those who want to view the frog. Increased visitation increases the 
risk of disease transmission.
    The prohibition of destruction or adverse modification of critical 
habitat is provided under section 7 of the Act and, therefore applies 
only to actions funded, authorized, or carried out by Federal agencies. 
``Destruction or adverse modification'' is defined under 50 CFR 402.02 
as an action that appreciably diminishes the value of critical habitat 
for the survival and recovery of the listed species. Similarly, section 
7 prohibits jeopardizing the continued existence of a listed species. 
``Jeopardize the continued existence'' is defined as an action that 
would be expected to reduce appreciably the likelihood of survival and 
recovery of a listed species.
    Given the similarity in the above definitions, in most cases 
Federal actions that would appreciably reduce the value of critical 
habitat for the survival and recovery of the Chiricahua leopard frog 
would also reduce appreciably the likelihood of survival and recovery 
of the species. The Chiricahua leopard frog occurs mostly in relatively 
small populations that are highly vulnerable to extirpation. Habitat 
alteration of a severity to result in destruction or adverse 
modification of critical habitat would likely also jeopardize the 
continued existence of the species. Similarly, reasonable and prudent 
alternative actions that would remove the likelihood of jeopardy would 
also remove the likelihood of destruction or adverse modification of 
critical habitat. While a critical habitat designation for habitat 
currently occupied by this species would not be likely to change the 
section 7 consultation outcome because an action that destroys or 
adversely modifies such critical habitat would also be likely to result 
in jeopardy to the species, in some situations section 7 consultation 
might be triggered only if critical habitat is designated. Examples 
could include unoccupied habitat or occupied habitat that may become 
unoccupied in the future. However, we investigated whether designating 
unoccupied habitat would provide some potential benefit. We are aware 
of only a few unoccupied sites that would be essential for the 
conservation of the Chiricahua leopard frog; the vast majority of 
essential sites are occupied. As a result, we see little benefit from 
the designation of unoccupied habitat. Designating critical habitat may 
also provide some educational or informational benefits. However, any 
added benefit would be outweighed by the publication of these 
additional areas in detailed maps that would subject the species to the 
threat of collecting, vandalism, and disease transmission.
    In balancing the benefits of critical habitat designation against 
the increased threats, we believe the records show that few, if any, 
benefits would be derived in this particular instance from designation 
of critical habitat. We believe that any potential benefits of critical 
habitat designation, beyond those afforded by listing, when weighed 
against the negative impacts of disclosing site-specific localities, 
does not yield an overall benefit. We, therefore, determine that 
critical habitat designation is not prudent for the Chiricahua leopard 

Special Rule

    As a means to promote conservation efforts on behalf of the 
Chiricahua leopard frog, we are proposing a special rule under section 
4(d) of the Act. Under the rule, take of Chiricahua leopard frog caused 
by livestock use of or maintenance activities at livestock tanks 
located on private or tribal lands would be exempt from section 9 of 
the Act. The rule targets tanks on private and tribal lands to 
encourage landowners and ranchers to continue to maintain these tanks 
that are not only important for livestock operations, but also provide 
habitat for leopard frogs. Livestock use and maintenance of tanks on 
Federal lands will be addressed through the section 7 process.

Available Conservation Measures

    Conservation measures provided to species listed as endangered or 
threatened under the Act include recognition, recovery actions, 
requirements for Federal protection, and prohibitions against certain 

[[Page 37354]]

Recognition through listing encourages and results in conservation 
actions by Federal, State, and private agencies, groups, and 
individuals. The Act provides for possible land acquisition and 
cooperation with the States and requires that recovery actions be 
carried out for all listed species. The protection required of Federal 
agencies and the prohibitions against taking and harm are discussed, in 
part, below.
    Section 7(a) of the Act, as amended, requires Federal agencies to 
evaluate their actions with respect to any species that is proposed or 
listed as endangered or threatened and with respect to its critical 
habitat, if any is designated or proposed. Regulations implementing 
this interagency cooperation provision of the Act are codified at 50 
CFR part 402. Section 7(a)(4) requires Federal agencies to confer with 
us on any action that is likely to jeopardize the continued existence 
of a proposed species or result in destruction or adverse modification 
of proposed critical habitat. If a species is listed or critical 
habitat is designated subsequently, Section 7(a)(2) requires Federal 
agencies to ensure that activities they authorize, fund, or carry out 
are not likely to jeopardize the continued existence of such a species 
or to destroy or adversely modify its critical habitat. If a Federal 
action may affect a listed species or its critical habitat, the 
responsible Federal agency must enter into consultation with us.
    The Chiricahua leopard frog occurs on Federal lands managed by the 
Coronado, Apache-Sitgreaves, Tonto, Coconino, and Gila National 
Forests; the Bureau of Land Management; and our refuges. Examples of 
Federal actions that may affect the Chiricahua leopard frog include 
dredge-and-fill activities, grazing programs, construction and 
maintenance of stock tanks, logging and other vegetation removal 
activities, management of recreation, road construction, fish stocking, 
issuance of rights-of-ways, prescribed fire and fire suppression, and 
discretionary actions authorizing mining. These and other Federal 
actions require Section 7 consultation if the action agency determines 
that the proposed action may affect listed species.
    Development on private or State lands requiring permits from 
Federal agencies, such as permits from the U.S. Army Corps of Engineers 
under section 404 of the Clean Water Act, would also be subject to the 
Section 7 consultation process. Federal actions not affecting the 
species, as well as actions that are not federally funded or permitted 
would not require Section 7 consultation. However, prohibitions under 
Section 9 of the Act (discussed below) would apply.
    Important regional efforts are currently under way to establish 
viable metapopulations of Chiricahua leopard frogs. We are currently 
working with the Arizona Game and Fish Department, New Mexico 
Department of Game and Fish, and several Federal and private landowners 
in these efforts. An ongoing regional conservation planning effort in 
the San Bernardino Valley, Arizona, being undertaken by this agency, 
the Forest Service, State, and private individuals is a good example of 
such efforts. Owners of the Magoffin Ranch, in particular, have devoted 
extensive efforts to conserving leopard frogs and habitat at stock 
tanks on that ranch. As part of the San Bernardino Valley conservation 
effort, a high school teacher and his students rear tadpoles in 
Douglas, Arizona, and established populations of Chiricahua leopard 
frogs in small constructed wetlands at Douglas area public schools 
(Biology 150 Class, Douglas High School 1998). In another regional 
conservation effort, the Tonto National Forest, Arizona, Arizona Game 
and Fish Department, and the Phoenix Zoo have developed a Chiricahua 
leopard frog ``conservation and management zone'' in which frogs have 
been reared and released into the wild to establish new populations 
(Sredl and Healy 1999). A similar regional conservation plan, involving 
The Nature Conservancy, Randy Jennings, and the New Mexico Game and 
Fish Department, is under way on the Mimbres River, New Mexico.
    We commend the individuals involved in these efforts. These 
regional conservation plans are proving grounds for developing the 
techniques to recover the species rangewide. As such, we strongly 
support them and encourage others to develop regional conservation 
plans; we will provide assistance and use our authorities to help 
develop and implement site-specific conservation activities for this 
species. If the Chiricahua leopard frog is listed, handling, rearing, 
translocation or other forms of direct or incidental take resulting 
from conservation activities can continue under section 10 permits from 
us. Incidental take associated with conservation plans may also be 
permitted pursuant to an incidental take statement in a biological 
opinion for activities under Federal jurisdiction. If the species is 
listed, we will work with the individuals involved in these 
conservation efforts to ensure that permits are issued promptly and 
that the process does not interrupt or hinder ongoing recovery actions.
    We are also exploring other opportunities to permit conservation 
activities. In particular, we encourage the public to comment on the 
desirability of promulgating a special rule under section 4(d) of the 
Act that would exempt from the section 9 take prohibitions activities 
associated with conservation plans. Eligible conservation plans would 
need to promote recovery and be approved by us and the appropriate 
State game and fish agency. Activities potentially addressed under such 
a plan, and which would be exempt from the section 9 take provisions, 
could include, but are not limited to, construction of new habitats or 
modification of existing habitats, fencing, enhancement or control of 
vegetation, translocation of frogs, and monitoring of frog populations.
    The Act and its implementing regulations set forth a series of 
general prohibitions and exceptions that apply to all threatened 
wildlife. These prohibitions, codified at 50 CFR 17.31, in part, make 
it illegal for any person subject to the jurisdiction of the United 
States to take (including harass, harm, pursue, hunt, shoot, wound, 
kill, trap, or collect, or attempt any such conduct), import or export, 
transport in interstate or foreign commerce in the course of a 
commercial activity, or sell or offer for sale in interstate or foreign 
commerce any threatened species unless provided for under a special 
rule. To possess, sell, deliver, carry, transport, or ship any such 
wildlife that has been taken illegally is also illegal. Certain 
exceptions will apply to persons acting in an agency capacity on the 
behalf of the Service and to activities associated with cooperative 
State conservation agencies.
    Permits may be issued to carry out otherwise prohibited activities 
involving threatened wildlife species under certain circumstances. 
Regulations governing permits are codified at 50 CFR 17.32. Such 
permits are available for scientific purposes, to enhance the 
propagation or survival of the species, and/or for incidental take in 
connection with otherwise lawful activities. For threatened species, 
permits also are available for zoological exhibition, educational 
purposes, or special purposes consistent with the purposes of the Act.
    Our policy (July 1, 1994; 59 FR 34272) is to identify to the 
maximum extent practicable at the time a species is listed those 
activities that would or would not likely constitute a violation of 
section 9 of the Act. The intent of this policy is to increase public 
awareness of the effect of the listing on proposed and ongoing 
activities within a species'

[[Page 37355]]

range. Based on the best available information, the following are 
examples of actions that would not likely result in a violation of 
section 9:
    (1) Actions that may affect Chiricahua leopard frog that are 
authorized, funded, or carried out by a Federal agency when the action 
is conducted in accordance with an incidental take statement issued by 
us pursuant to section 7 of the Act;
    (2) Actions that may result in take of Chiricahua leopard frog when 
the action is conducted in accordance with a permit under section 10 of 
the Act;
    (3) Recreational activities that do not destroy or significantly 
degrade occupied habitat, and do not result in take of frogs;
    (4) Release, diversion, or withdrawal of water from or near 
occupied habitat in a manner that does not displace or result in 
desiccation or death of eggs, tadpoles, or adults; does not disrupt 
breeding activities of adults; does not favor introduction of nonnative 
predators; and does not alter vegetation characteristics at or near 
occupied sites to an extent that exposes the frogs to increased 
predation; and
    (5) Logging activities that do not result in erosion or siltation 
of stream beds and other aquatic habitats occupied by Chiricahua 
leopard frogs, do not adversely affect water quality, and do not denude 
shoreline vegetation or terrestrial vegetation in occupied habitat.
    Activities that we believe could potentially result in ``take'' of 
the Chiricahua leopard frog, include, but are not limited to the 
    (1) Unauthorized collection, capture or handling of the species;
    (2) Intentional introduction of nonnative predators, such as 
nonnative fish, bullfrogs, crayfish, or tiger salamanders;
    (3) Any activity not carried out pursuant to the proposed special 
rule (described at the end of this document) in ``Sec. 17.43 Special 
rules-amphibians'' that results in destruction or significant 
alteration of habitat of Chiricahua leopard frog including, but not 
limited to, the discharge of fill material, the diversion or alteration 
of stream flows and aquatic habitats occupied by the species or 
withdrawal of water to the point at which habitat becomes unsuitable 
for the species, and the alteration of the physical channels within the 
stream segments and aquatic habitats occupied by the species;
    (4) Water diversions, groundwater pumping, water releases, or other 
water management activities that result in displacement or death of 
eggs, tadpoles, or adult frogs; disruption of breeding activities; 
introduction of nonnative predators; or significant alteration of 
vegetation characteristics at or near occupied sites. However, pursuant 
to the proposed special rule for this species, operation and 
maintenance of livestock tanks on private or tribal lands that result 
in incidental mortality of frogs would not be considered a violation of 
section 9;
    (5) Discharge or dumping of hazardous materials, silt, or other 
pollutants into waters supporting the species;
    (6) Possession, sale, delivery, transport, or shipment of illegally 
taken Chiricahua leopard frogs; and
    (7) Actions that take Chiricahua leopard frogs that are not 
authorized by either a permit under section 10 of the Act or an 
incidental take statement under section 7 of the Act, or are identified 
as prohibited in the special rule ``Sec. 17.43 Special rules-
amphibians'' for this species; the term ``take'' includes harassing, 
harming, pursuing, hunting, shooting, wounding, killing, trapping, 
capture, or collecting, or attempting any of these actions.
    In the description of activities above, a violation of section 9 
would occur if those activities occur to an extent that would result in 
``take'' of Chiricahua leopard frog. Not all of the activities 
mentioned above will result in violation of section 9 of the Act; only 
those activities that result in ``take'' of Chiricahua leopard frog 
would be considered violations of section 9. Direct your questions 
regarding whether specific activities will constitute a violation of 
section 9 to the Field Supervisor, Arizona Ecological Services Field 
Office (see ADDRESSES section). Address your requests for copies of the 
regulations on listed wildlife and inquiries about prohibitions and 
permits to the U.S. Fish and Wildlife Service, Branch of Endangered 
Species/Permits, P.O. Box 1306, Albuquerque, New Mexico 87103 
(telephone (505)248-6920, facsimile (505)248-6922).

Public Comments Solicited

    We intend for any final action resulting from this proposal to be 
as accurate and as effective as possible. Therefore, we solicit 
comments or suggestions from the public, other concerned governmental 
agencies, the scientific community, industry, or any other interested 
party concerning this proposed rule. We particularly seek comments 
    (1) Biological, commercial trade, or other relevant data concerning 
any threat (or lack thereof) to the Chiricahua leopard frog;
    (2) The location of any additional populations of Chiricahua 
leopard frog and the reasons why any habitat should or should not be 
determined to be critical habitat as provided by section 4 of the Act;
    (3) Additional information concerning the range, distribution, and 
population size of the Chiricahua leopard frog;
    (4) Current or planned activities in the subject area and their 
possible impacts on the Chiricahua leopard frog; and
    (5) Additional information pertaining to the promulgation of a 
special rule to exempt from the section 9 take prohibitions livestock 
use of and maintenance activities at livestock tanks located on private 
or tribal lands. Although beyond the scope of the currently proposed 
special rule, we also solicit comment on the desirability of a special 
rule that would exempt from the section 9 take prohibitions activities 
associated with conservation plans that promote recovery and are 
approved by us and the appropriate State game and fish agency.
    Our practice is to make comments, including names and home 
addresses of respondents, available for public review during regular 
business hours. Individual respondents may request that we withhold 
their home address from the rulemaking record, which we will honor to 
the extent allowable by law. In some circumstances, we would withhold 
from the rulemaking record a respondent's identity, as allowable by 
law. If you wish for 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. 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 (see ADDRESSES 
    In making a final decision on this proposed rule, we will take into 
consideration the comments and any additional information we receive. 
The final rule may differ as a result of this process.
    The Act provides for one or more public hearings on this proposal, 
if requested. We must receive requests within 45 days of the date of 
publication of the proposal in the Federal Register. Such requests must 
be made in writing and be addressed to the Field Supervisor (see 
ADDRESSES section).
    Executive Order 12866 requires each agency to write regulations and 
notices that are easy to understand. We invite

[[Page 37356]]

your comments on how to make this proposed rule easier to understand 
including answers to questions such as the following: (1) Are the 
requirements in the proposed rule clearly stated? (2) Does the proposed 
rule contain technical language or jargon that interferes with the 
clarity? (3) Does the format of the proposed rule (grouping and order 
of sections, use of headings, paragraphing, etc.) aid or reduce its 
clarity? (4) Is the description of the proposed rule in the 
``Supplementary Information'' section of the preamble helpful in 
understanding the notice? What else could we do to make the proposed 
rule easier to understand?
    Send a copy of any comments that concern how we could make this 
proposed rule easier to understand to the Field Supervisor (see 
ADDRESSES section).

Required Determinations

    Prior to publication of the final rule, we will analyze the 
economic effects of the special rule and will determine whether the 
special rule is in compliance with the following. We will announce the 
availability of our analysis in a separate Federal Register notice:
    (1) Regulatory Planning and Review
    (2) Regulatory Flexibility Act (5 U.S.C. 601 et seq.)
    (3) Small Business Regulatory Enforcement Fairness Act (5 U.S.C. 
    (4) Unfunded Mandates Reform Act (2 U.S.C. 1501 et seq.)
    (5) Taking Personal Property Rights (Executive Order 12630)
    (6) Federalism (Executive Order 13132)
Civil Justice Reform
    In accordance with Executive Order 12988, the Department of the 
Interior's Office of the Solicitor determined that this proposed 
special rule does not unduly burden the judicial system and meets the 
requirements of sections 3(a) and 3(b)(2) of the Order. The Office of 
the Solicitor will review the final special rule. We will make every 
effort to ensure that the final special rule contains no drafting 
errors, provides clear standards, simplifies procedures, reduces 
burden, and is clearly written such that litigation risk is minimized.
Paperwork Reduction Act of 1995 (44 U.S.C. 3501 et seq.)
    This proposed rule and special rule does not contain any 
information collection requirements for which Office of Management and 
Budget (OMB) approval under the Paperwork Reduction Act of 1995 (44 
U.S.C. 3501 et seq.) is required. An information collection related to 
the rule pertaining to permits for endangered and threatened species 
has OMB approval and is assigned clearance number 1018-0094. An agency 
may not conduct or sponsor, and a person is not required to respond to 
a collection of information unless it displays a currently valid OMB 
control number. This proposed rule and special rule does not alter that 
information collection requirement. For additional information 
concerning permits and associated requirements for threatened species, 
see 50 CFR 17.32.

National Environmental Policy Act

    We determined that we do not need to prepare Environmental 
Assessments and Environmental Impact Statements, as defined under the 
authority of the National Environmental Policy Act of 1969, in 
connection with regulations adopted pursuant to Section 4(a) of the 
Endangered Species Act of 1973, as amended. We published a notice 
outlining the basis for this determination in the Federal Register on 
October 25, 1983 (48 FR 49244).

References Cited

    A complete list of all references cited in this rule is available 
upon request from the Arizona Ecological Services Field Office (see 
ADDRESSES section).
    Author: The primary author of this notice is James Rorabaugh (see 
ADDRESSES section).

List of Subjects in 50 CFR Part 17

    Endangered and threatened species, Exports, Imports, Reporting and 
recordkeeping requirements, Transportation.

Proposed Regulation Promulgation

    We propose to amend part 17, subchapter B of chapter I, title 50 of 
the Code of Federal Regulations, as set forth below:


    1. The authority citation for part 17 continues to read as follows:

    Authority: 16 U.S.C. 1361-1407; 16 U.S.C. 1531-1544 16 U.S.C. 
4201-4245; Pub. L. 99-625, 100 Stat. 3500; unless otherwise noted.

    2. Amend section 17.11(h) by adding the following in alphabetical 
order, under AMPHIBIANS, to the List of Endangered and Threatened 

Sec. 17.11  Endangered and threatened wildlife.

* * * * *
    (h) * * *

                      Species                                                Vertebrate
----------------------------------------------------                      population where                                 Critical
                                                       Historic range       endangered or        Status     When listed    habitat       Special rules
          Common name              Scientific name                           threatened

                   *                  *                  *                  *                  *                  *                  *
Frog, Chiricahua leopard.......  Rana                U.S.A. (AZ, NM),    Entire............  T              ...........           NA  Sec.  17.43(b)
                                  chiricahuensis.     Mexico.

                   *                  *                  *                  *                  *                  *                  *

[[Page 37357]]

    3. We propose to amend 50 CFR 17.43 by adding paragraph (b) to read 
as follows:

Sec. 17.43  Special rules--amphibians.

* * * * *
    (b) What species is covered by this special rule? Chiricahua 
leopard frog (Rana chiricahuensis).
    (1) What activities are prohibited? Except as noted in paragraph 
(b)(2) of this section, all prohibitions of Sec. 17.31 will apply to 
the Chiricahua leopard frog.
    (2) What activities are allowed on private or tribal land? 
Incidental take of the Chiricahua leopard frog will not be considered a 
violation of section 9 of the Act, if the incidental take results from 
livestock use of or maintenance activities at livestock tanks located 
on private or tribal lands. A livestock tank is defined as an existing 
or future impoundment in an ephemeral drainage or upland site 
constructed primarily as a watering site for livestock.

    Dated: May 19, 2000.
Donald J. Barry,
Assistant Secretary for Fish and Wildlife and Parks.
[FR Doc. 00-14972 Filed 6-13-00; 8:45 am]