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establish a voluntary labeling regime for unidirectional digital cable television Endangered Species Act of 1973, as unidirectional digital cable television receivers and related digital cable amended. After review of all available receivers and related digital cable products that meet certain technical scientific and commercial information, products that meet certain technical specifications. This regime would we find that the petitioned action is specifications. This regime would include testing and self-certification warranted, but precluded by higher include testing and self-certification standards, as well as consumer priority actions to amend the Lists of standards, as well as consumer information disclosures to purchasers of Endangered and Threatened Wildlife information disclosures to purchasers of such receivers and products. and Plants. Upon publication of this 12- such receivers and products. Compliance may also require month petition finding, this species will Compliance may also require multichannel video programming be added to our candidate species list. multichannel video programming distributors to encode certain We will develop a proposed rule to list distributors to encode certain commercial audiovisual content to this population pursuant to our Listing commercial audiovisual content to prevent or limit its copying and prohibit Priority System. prevent or limit its copying and prohibit the use of selectable output controls. the use of selectable output controls. Cable operators with systems of 750 DATES: The finding announced in this Cable operators with systems of 750 MHz or greater activated channel document was made on January 10, MHz or greater activated channel capacity may be required to support 2003. Comments and information may capacity may be required to support operation of unidirectional digital cable be submitted until further notice. operation of unidirectional digital cable products on digital cable systems and to ADDRESSES: You may send data, products on digital cable systems and to ensure that navigation devices utilized information, comments, or questions ensure that navigation devices utilized in connection with such systems have concerning this finding to the Field in connection with such systems have an IEEE 1394 interface and comply with Supervisor (Attn: MYLF), Sacramento an IEEE 1394 interface and comply with specified technical standards. However, Fish and Wildlife Office, U.S. Fish and specified technical standards. While we welcome comment on modifications Wildlife Service, 2800 Cottage Way, these requirements could have an of the proposals if based on evidence of Room W–2605, Sacramento, California impact on consumer electronics potential differential impact on smaller 95825. You may inspect the petition, manufacturers and multichannel video entities. In addition, the Regulatory administrative finding, supporting programming distributors, it remains Flexibility Act requires agencies to seek information, and comments received, unclear weather there would be a comment on possible small entity- during normal business hours by differential impact on small entities. We related alternatives, as noted above. We appointment, at the above address. seek comment on whether the burden of therefore seek comment on alternatives these requirements would fall on large to the proposed rules that would assist FOR FURTHER INFORMATION CONTACT: and small entities differently. small entities while maintaining the Peter Epanchin, Susan Moore, or Chris 32. Steps Taken to Minimize compromise reached in the Nagano at the above address (telephone, Significant Impact on Small Entities, Memorandum of Understanding. (916) 414–6600; fax, (916) 414–6710). and Significant Alternatives Considered. 34. Federal Rules Which Duplicate, SUPPLEMENTARY INFORMATION: The RFA requires an agency to describe Overlap, or Conflict with the any significant alternatives that it has Commission’s Proposals. None. Background considered in reaching its proposed Federal Communications Commission. approach, which may include the Section 4(b)(3)(B) of the Endangered following four alternatives (among Marlene H. Dortch, Species Act of 1973, as amended (Act) others): (1) The establishment of Secretary. (16 U.S.C. 1531 et seq.), requires that, differing compliance or reporting [FR Doc. 03–948 Filed 1–15–03; 8:45 am] for any petition to revise the List of requirements or timetables that take into BILLING CODE 6712–01–P Threatened and Endangered Species account the resources available to small that contains substantial scientific and entities; (2) the clarification, commercial information that listing may consolidation, or simplification of DEPARTMENT OF THE INTERIOR be warranted, we make a finding within compliance or reporting requirements 12 months of the date of the receipt of under the rule for small entities; (3) the Fish and Wildlife Service the petition on whether the petitioned use of performance, rather than design, action is: (a) Not warranted, or (b) standards; and (4) an exemption from 50 CFR Part 17 warranted, or (c) warranted but that the coverage of the rule, or any part thereof, immediate proposal of a regulation Endangered and Threatened Wildlife for small entities. implementing the petitioned action is 33. As indicated above, the FNPRM and Plants; 12-Month Finding for a precluded by other pending proposals to seeks comment on whether the Petition To List the Sierra Nevada determine whether any species is Commission should adopt or revise Distinct Population Segment of the threatened or endangered, and rules relating to the creation of a cable Mountain Yellow-legged Frog (Rana expeditious progress is being made to ‘‘plug and play’’ standard for digital muscosa). add or remove qualified species from cable television receivers and other AGENCY: Fish and Wildlife Service, the List of Threatened and Endangered digital cable television consumer Interior. Species. Section 4(b)(3)(C) of the Act electronics equipment in order to ACTION: Notice of 12-month petition requires that a petition for which the facilitate the DTV transition. This finding. requested action is found to be regime may require may require the warranted but precluded shall be treated manufacture of digital cable television SUMMARY: We, the U.S. Fish and as though resubmitted on the date of receivers and other digital cable Wildlife Service (Service), announce a such finding, i.e., requiring a television consumer electronics 12-month finding for a petition to list subsequent finding to be made within equipment. Consumer electronics the Sierra Nevada distinct population 12 months. Such 12-month findings are manufacturers may be required to segment of the mountain yellow-legged to be published promptly in the Federal establish a labeling regime for frog (Rana muscosa) under the Register.

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Taxonomy have three firm jelly-like transparent typically are encountered in the upper Camp (1917) described the mountain envelopes surrounding a grey-tan or half of that elevation range (Zweifel yellow-legged frog as two subspecies of black vitelline (egg yolk) capsule 1955; Mullally and Cunningham 1956; Rana boylii: R. b. sierrae in the Sierra (Wright and Wright 1949). Stebbins 1985). The larvae (tadpoles) of this species Nevada, and R. b. muscosa in southern generally are mottled brown in dorsal Habitat Requirements California. On the basis of the similar coloration with a golden tint and a Mountain yellow-legged frogs rarely morphological (body structure) faintly-yellow venter (underside) are found more than 1 m (3.3 ft) from characteristics of the two subspecies, (Zweifel 1955; Stebbins 1985). Total water (Stebbins 1951; Mullally and the small number of sites where both tadpole length reaches 72 mm (2.8 in), Cunningham 1956; Bradford et al. were found, and breeding experiments, its body is flattened, and the tail 1993). At the lower elevations in the R. b. muscosa and R. b. sierrae were musculature is wide, about 2.5 Sierra Nevada, the species usually is split from the R. boylii group and centimeters (cm) (1 in) or more, before associated with rocky stream beds and combined under a single species, R. tapering into a rounded tip (Wright and wet meadows surrounded by coniferous muscosa (Zweifel 1955). Genetic studies Wright 1949). The mouth has a forest (Zweifel 1955; Zeiner et al. 1988). also have concluded that R. muscosa maximum of 7 labial (lip) tooth rows (2– At higher elevations, the species and R. boylii are distinct species (Case 3 upper and 4 lower) (Stebbins 1985). occupies lakes, ponds, tarns, and 1978; Davis 1986; Green 1986a, 1986b; Larvae often take 2 to 4 years or more streams (Zweifel 1955; Mullally and Hillis and Davis 1986; Macey et al. to reach metamorphosis (transformation Cunningham 1956; Stebbins 1985). The 2001). from larvae to frogs) (Wright and Wright borders of alpine (above treeline) lakes Description 1949; Cory 1962b; Bradford 1983; and montane (mountain) meadow Bradford et al. 1993; Knapp and streams used by mountain yellow- The body length (snout to vent) of the Matthews 2000). legged frogs are frequently grassy or mountain yellow-legged frog ranges muddy; this differs from the sandy or from 40 to 80 millimeters (mm) (1.5 to Range rocky shores that are inhabited by the 3.25 inches (in)) (Jennings and Hayes The mountain yellow-legged frog is amphibian in lower elevation streams 1994). Females average slightly larger restricted to two disjunct areas in (Zweifel 1955). Adults typically are than males and males have a swollen, California and a portion of Nevada. One found sitting on rocks along the darkened thumb base (Wright and area is in the Sierra Nevada and the shoreline, usually where there is little or Wright 1949; Stebbins 1951; Zweifel other area is in the San Gabriel, San no vegetation (Mullally and 1955, 1968). Dorsal (upper) coloration in Bernardino, and San Jacinto mountain Cunningham 1956). Although the adults may be variable, exhibiting a mix ranges of southern California (Los species may use a variety of shoreline of brown and yellow, but it also can be Angeles, San Bernardino, Riverside, and habitats, both larvae and adults are less grey, red, or green-brown, and usually San Diego counties) (Zweifel 1955; common at shorelines which drop patterned with dark spots (Stebbins Jennings and Hayes 1994). The southern abruptly to a depth of 60 cm (2 ft) than 1985; Jennings and Hayes 1994). These California population is isolated from at open shorelines that gently slope up spots may be large (6 mm (0.25 in)) and the Sierra Nevada population by the to shallow waters of only 5–8 cm (2–3 few, smaller and more numerous, or a Tehachapi mountain range, with a in) deep (Mullally and Cunningham mixture of both (Zweifel 1955). Irregular distance of about 225 kilometers (km) 1956; Jennings and Hayes 1994). lichen or moss-like patches (to which (140 miles (mi)) between the two Mountain yellow-legged frogs also use the name muscosa refers) also may be populations. stream habitats, especially in the present on the dorsal surface (Zweifel In the Sierra Nevada, the historic northern part of their range. Streams 1955; Stebbins 1985). The belly and distribution of the mountain yellow- utilized by adults vary from those undersurfaces of the hind limbs are legged frog was more or less continuous having high gradients with numerous yellow or orange, and this pigmentation from the vicinity of La Porte in southern pools, rapids, and small waterfalls, to on the abdomen may extend forward to Plumas County southward to Taylor and those with low gradients with slow the forelimbs (Wright and Wright 1949; French Joe Meadows in southern Tulare flows, marshy edges, and sod banks Stebbins 1985). This species may County (Jennings and Hayes 1994). (Zweifel 1955). Aquatic substrates vary produce a distinctive mink or garlic-like Records for this species in the Sierra from bedrock to fine sand, rubble (rock odor when disturbed (Wright and Nevada document its occurrence on the fragments), and boulders (Zweifel 1955). Wright 1949; Stebbins 1985). Although east and west sides of the crest in all Mountain yellow-legged frogs seem to the species lacks vocal sacks, it can major drainages from Plumas to Tulare be absent from the smallest creeks, make both terrestrial and underwater counties, with a single record from Kern probably because these have insufficient vocalizations, which have been County (Zweifel 1955; Jennings and depth for adequate refuge and described as a flat clicking sound Hayes 1994; Knapp 1996). Except for overwintering habitat (Jennings and (Zweifel 1955; Stebbins 1985; Ziesmer historic populations in extreme western Hayes 1994). 1997). The mountain yellow-legged frog Nevada in Washoe and Douglas Both adults and larvae overwinter for has smoother skin, generally heavier counties, on Mt. Rose near Lake Tahoe, up to 9 months in the bottoms of lakes spotting and mottling dorsally, and possibly Edgewood Creek, and that are at least 1.7 m (5.6 ft) deep; darker toe tips than the foothill yellow- elsewhere around Lake Tahoe, the however, overwinter survival may be legged frog (R. boylii) (Zweifel 1955; species is confined to California greater in lakes that are at least 2.5 m Stebbins 1985). (Zweifel 1955). The elevational range for (8.2 ft) deep, under ledges of stream or Eggs of the mountain yellow-legged the mountain yellow-legged frog in the lake banks, or in rocky streams frog are laid in globular clumps, which Sierra Nevada ranges from (Bradford 1983; V. Vredenburg et al. (in are often somewhat flattened, roughly approximately 1,370 meters (m) (4,500 press)). In some instances, frogs have 2.5 to 5 cm (1 to 2 in) across (Stebbins feet (ft)) at San Antonio Creek, near been found to overwinter in underwater 1985). When eggs are close to hatching, Dorrington in Calaveras County, to over bedrock crevices between 0.2 m (0.7 ft) egg mass volume may average 198 cubic 3,650 m (12,000 ft) at Desolation Lake in and 1 m (3.3 ft) below the water surface cm (78 cubic in) (Pope 1999a). Eggs Fresno County, though populations (Matthews and Pope 1999) and the use

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of such crevices appears to allow them the mountain yellow-legged frogs were Simberloff (1997) stated: ‘‘* * *the to survive in shallower water bodies utilizing rock crevices near shore, two key premises in this approach to that freeze to the bottom in winter (Pope crevices, holes, and ledges where water population biology are that populations 1999a). In lakes and ponds that do not depths ranged from 0.2 m (0.7 ft) to 1.5 are spatially structured in assemblages freeze to the bottom in winter, mountain m (5 ft) (Matthews and Pope 1999). The of local breeding populations and that yellow-legged frogs may overwinter in granite surrounding these overwintering migration among the local populations the shelter of bedrock crevices as a habitats may insulate the mountain has some effect on local dynamics, behavioral response to the presence of yellow-legged frogs from the extreme including the possibility of population introduced fishes (V. Vredenburg et al. winter temperatures, providing that reestablishment following extinction.’’ (in press)). there is an adequate supply of oxygen Adult mountain yellow-legged frogs Adult mountain yellow-legged frogs either in the water or air (Matthews and are thought to feed preferentially upon breed in the shallows of ponds or in Pope 1999). terrestrial insects and adult stages of inlet streams and are often seen on wet Larvae maintain a relatively high aquatic insects while on the shore and substrates within 1 m (3 ft) of the body temperature by selecting warmer in shallow water (Bradford 1983). water’s edge (Zweifel 1955). Adults microhabitats (Bradford 1984). During Feeding studies on Sierra Nevada emerge from overwintering sites winter, larvae remain in warmer water mountain yellow-legged frogs are immediately following snowmelt and below the thermocline (thermally limited. Remains found inside the will move over ice to get to breeding stratified water); after spring overturn stomachs of mountain yellow-legged sites (Pope 1999a; V. Vredenburg in litt. (thaw and thermal mixing of the water), frogs in southern California include a 2002). Mountain yellow-legged frogs in they continue to behaviorally modulate wide variety of invertebrates, including the Sierra Nevada deposit their eggs their body temperature by daily beetles, ants, bees, wasps, flies, true- underwater in clusters, which they movements: during the day, larvae move bugs, and dragonflies (Long 1970). attach to rocks, gravel, vegetation, or to warm, shallow, nearshore water, and Larger frogs take more aquatic true bugs under banks (Wright and Wright 1949; during the late afternoon and evening, (insects in the taxonomic order Stebbins 1951; Zweifel 1955; Pope they retreat to the warmer waters off Hemiptera) probably because of their 1999a). Clutch size varies from 15 to 350 shore (Bradford 1984). more aquatic behavior (Jennings and eggs per egg mass (Livezey and Wright The time required to reach Hayes 1994). Adult mountain yellow- 1945; V. Vredenburg et al. (in press)). In reproductive maturity is thought to vary legged frogs have been observed eating laboratory breeding experiments, egg between 3 and 4 years after Yosemite toad (Bufo canorus) and hatching times ranged from 18 to 21 metamorphosis (Zweifel 1955). Pacific treefrog (Pseudacris regilla) days at temperatures ranging from 5 to Longevity of adults is unknown, but larvae (Mullally 1953; Zeiner et al. 13.5 Celsius (°C ) (41 to 56 Fahrenheit adult survivorship from year to year is 1988; Pope 1999b; Feldman and (°F)) (Zweifel 1955). Field observations very high, so they are undoubtedly long- Wilkinson 2000) and can be are similar (Pope 1999a). lived amphibians (Matthews and Pope cannibalistic (Heller 1960). Mountain The time required to develop from 1999; Pope 1999a). Although data yellow-legged frog larvae graze on fertilization to metamorphosis is currently are limited, evidence exists benthic detritus, algae, and diatoms believed to vary between 1 and 4 years that mountain yellow-legged frogs along rocky bottoms in streams, lakes, (Storer 1925; Wright and Wright 1949; display strong site fidelity and return to and ponds (Bradford 1983; Zeiner et al. Zweifel 1955; Cory 1962b; V. the same overwintering and summer 1988). Larvae have also been observed Vredenburg et al. (in press)). Since habitats from year to year (Pope 1999a). cannibalizing conspecific (of the same larvae must overwinter at least two or In aquatic habitats, mountain yellow- species) eggs (Vredenburg 2000). In three times before metamorphosis, legged frog adults typically move only a addition, larvae have been seen feeding successful breeding sites are located in, few hundred meters (few hundred on the carcasses of dead or connected to, lakes and ponds that do yards) (Matthews and Pope 1999; Pope metamorphosed frogs (V. Vredenburg et not dry in the summer, and that are 1999a), but distances of up to 1 km (0.62 al. (in press)). sufficiently deep so as to not completely mi) have been recorded (V. Vredenburg freeze through in winter (Bradford et al. (in press)). Adults tend to move Status 1983). Larval survival to metamorphosis between selected breeding, feeding, and The distribution of the Sierra Nevada is possible in lakes that do not dry out overwintering habitats during the course mountain yellow-legged frog is during the summer. Knapp and of the year. Though adults are typically restricted primarily to publicly managed Matthews (2000) found the number of found within 1 m (3.3 ft) of water, lands at high elevations, including larvae was larger in fishless water overland movements of over 65 m (215 streams, lakes, ponds, and meadow bodies deeper than 2 m (6.5 ft). Bradford ft) have been recorded (Pope 1999a); the wetlands located on national forests, (1983) found that mountain yellow- furthest reported distance of a mountain including wilderness and non- legged frog die-offs sometimes result yellow-legged frog from water is 400 m wilderness on the forests, and national from oxygen depletion during winter in (1,300 ft) (V. Vredenburg et al. (in parks. Approximately 210 known lakes less than 4 m (13 ft) deep. press). Almost no data exist on the mountain yellow-legged frog However, larvae may survive for months dispersal of juvenile mountain yellow- populations (or populations within in nearly anoxic (oxygen-deficient) legged frogs away from breeding sites metapopulations) exist on the national conditions when shallow lakes are (Bradford 1991). However, juveniles that forests within the Sierra Nevada, though frozen to the bottom. Recent studies may be dispersing to permanent water not all of these populations may be have reported populations of mountain have been observed in small reproducing successfully. In the yellow-legged frogs overwintering in intermittent streams (Bradford 1991). national parks of the Sierra Nevada, lakes less than 1.5 m (5 ft) deep that Mountain yellow-legged frog population there are 758 known sites with were assumed to have frozen to the dynamics are thought to have a mountain yellow legged-frogs, most of bottom, and yet healthy frogs were metapopulation structure (Bradford et which occur within 59 different basins documented to emerge the following al. 1993; Drost and Fellers 1996; Knapp that have multiple breeding populations July (Matthews and Pope 1999; Pope and Matthews 2000). In describing the that are connected hydrologially, so that 1999a). Radio telemetry indicated that metapopulation concept, Hanski and populations in each basin function as

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metapopulations). Within these 758 2000). The most pronounced declines on the Kaweah River, a western sites, 330 populations exist for which have occurred north of Lake Tahoe in watershed within Sequoia National we have evidence of successful the northernmost 125 km (78 mi) Park, and did not detect mountain reproduction. Overall, we estimate that portion of the range, and south of yellow-legged frogs at any of these 22 percent of the remaining mountain Sequoia and Kings Canyon National locations. They resurveyed 21 historic yellow-legged frog sites within the Parks in Tulare County in the sites within the Kern, Kings, and San Sierra Nevada are found within the southernmost 50 km (31 mi) portion, Joaquin River watersheds in Sequoia national forests (including those with where only a few populations remain and Kings Canyon National Parks, and and those without evidence of (Fellers 1994; Jennings and Hayes 1994). detected mountain yellow-legged frogs successful reproduction), while 78 Based on available USFS survey and at 11 of these sites. Frogs were detected percent are found within the national observation data, there appear to be very at three locations out of 24 historic sites parks (including those with and those few or no known large populations outside of Sequoia and Kings Canyon without evidence of successful north of the Plumas National Forest. National Parks. Rangewide, their reproduction). These percentages Mountain yellow-legged frogs resurvey effort detected mountain represent the number of sites within the historically occurred in Nevada on the yellow-legged frogs at 14 of 72 historic national forests and the national parks slopes of Mount Rose in Washoe County sites, representing an 80 percent of the Sierra Nevada; they do not and probably in the vicinity of Lake population decline. On the basis of represent the number of individuals Tahoe in Douglas County (Linsdale these results, Bradford et al. (1994a) present at each site. The methods for 1940; Zweifel 1955; Jennings 1984). In estimated a 50 percent population measuring the numbers of populations 1994 and 1995, mountain yellow-legged decline in Sequoia and Kings Canyon and metapopulations in the national frog surveys were conducted by Panik National Parks, with more pronounced forests and the national parks have not (1995) at 54 sites in the Carson Range declines elsewhere in the mountain been standardized and, therefore we of Nevada and California, including yellow-legged frog’s range. must use caution when we compare eight historic locations; no mountain Drost and Fellers (1996) surveyed for national forests numbers to national yellow-legged frogs were observed. A mountain yellow-legged frogs at sites park numbers. However, the remaining few scattered and unconfirmed sightings documented by Grinnell and Storer populations of mountain yellow-legged were reported in Nevada in the late (1924) in the early part of the 20th frogs are more numerous and larger in 1990s, but any populations remaining in Century. The frog was reported to be the size in the national parks than in the this State are likely to be extremely most common amphibian where they national forests. small and the species is thought to be surveyed in the Yosemite area (Grinnell National forests with extant extirpated from Nevada (R. Panik, and Storer 1924). Drost and Fellers populations of mountain yellow-legged Western Nevada Community College, in (1996) repeated Grinnell and Storer’s frogs include the Plumas National litt., 2002). 1924 survey and reported mountain Forest, Tahoe National Forest, The number of extant populations of yellow-legged frog presence at only 2 of Humboldt-Toiyabe National Forest, the mountain yellow-legged frogs in the the 14 sites where this animal had been Lake Tahoe Basin Management Unit Sierra Nevada is greatly reduced. previously detected. These two positive (managed by the U.S. Forest Service Remaining populations are patchily sightings consisted of a single larva at (USFS)), Eldorado National Forest, scattered throughout nearly all their one site and a single adult female at Stanislaus National Forest, Sierra historic range (Jennings and Hayes 1994; another site. Drost and Fellers (1996) National Forest, Sequoia National Jennings 1995, 1996). At the identified and surveyed 17 additional Forest, and Inyo National Forest. northernmost portions of the range in sites with suitable mountain yellow- National parks with extant populations Butte and Plumas counties, few legged frog habitat, and these surveys of mountain yellow-legged frogs include populations have been seen or resulted in the detection of three Yosemite National Park, Kings Canyon discovered since 1970 (Jennings and additional populations. National Park, and Sequoia National Hayes 1994). Declines have also been For the 86 historically occupied Park. noted in the central and southern Sierra mountain yellow-legged frog sites Grinnell and Storer (1924) first (Drost and Fellers 1996). In the southern documented between 1915 and 1959 observed declines of mountain yellow- Sierra Nevada (Sierra, Sequoia, and Inyo and resurveyed by Bradford et al. legged frog populations. Since then, a National Forests; and Sequoia, Kings (1994a) and Drost and Fellers (1996), an number of researchers have reported Canyon, and Yosemite National Parks), 80 percent decline occurred in the that the mountain yellow-legged frog there are relatively large populations number of historical frog populations. has disappeared from a significant (e.g., breeding populations of over 20 Of the 86 historic sites, only 16 portion of its historic range in the Sierra adults) of mountain yellow-legged frogs; remained occupied at the time of Nevada (Hayes and Jennings 1986; however, in recent years, some of the resurvey. Bradford 1989; Jennings and Hayes largest of these populations have been Knapp and Matthews (2000) surveyed 1994; Bradford et al. 1994a; Jennings extirpated (Bradford 1991; Bradford et more than 1,700 high elevation 1995, 1996; Stebbins and Cohen 1995; al. 1994a; R. Knapp, Sierra Nevada (averaging 3,400 m (11,150 ft)) lakes and Drost and Fellers 1996; Knapp and Aquatic Research Laboratory, in litt. ponds in the Sierra National Forest’s Matthews 2000). The observed declines 2002). Mountain yellow-legged frog John Muir Wilderness Area and in Kings of mountain yellow-legged frog populations are more numerous and Canyon National Park, encompassing a populations in the 1970s were small larger in size in the national parks of the total of approximately 100,000 hectares relative to the declines observed during Sierra Nevada than in the surrounding (ha) (247,000 acres (ac)). They found a the 1980s and 1990s. Rangewide, it is USFS lands (Bradford et al. 1994a; strong negative correlation between estimated that mountain yellow-legged Knapp and Matthews 2000). introduced trout and the distribution of frog populations have undergone a 50 to Between 1988 and 1991, Bradford et mountain yellow-legged frogs. In the 80 percent reduction in size (Bradford et al. (1994a) resurveyed sites known summer of 2002, Knapp (in litt. 2002) al. 1994a; Jennings 1995; Stebbins and historically (between 1955 and 1979) to resurveyed 302 water bodies determined Cohen 1995; Drost and Fellers 1996; have contained mountain yellow-legged by 1995 to 1997 surveys to be occupied Jennings 1996; Knapp and Matthews frogs. They resurveyed 27 historic sites by mountain yellow-legged frogs, and

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resurveyed 744 of over 1,400 sites where documented. However, most of the mountain yellow-legged frog (Stebbins frogs were not previously detected. estimated 55 populations are small, 1985). A distributional map of mountain Knapp found no change in status at 59 consisting of only a few individuals (T. yellow-legged frogs produced by percent of these sites, but found that 41 Hopkins, USFS, pers. comm., 2002). The Jennings and Hayes (1994) indicates percent of the sites had gone extinct, species appears to have disappeared historic collections of this species while 8 percent of previously from a significant number of historic within the Humboldt-Toiyabe National unoccupied sites were colonized. These locations, and the abundance of the Forest in California. Resurveys of data indicate an extinction rate that is species at known sites appears to be locations where mountain yellow-legged 5 to 6 times higher than the colonization quite low. frogs occurred indicate that the species rate within this study area. This high Tahoe National Forest: Mountain had become extirpated by 1992 at a rate of extinction over a 5- to-7-year yellow-legged frogs were present number of locations in Humboldt- time frame suggests the species may historically throughout the Tahoe Toiyabe National Forest (Jennings and become extinct within a few decades National Forest and the surrounding Hayes 1994). Surveys in California are (assuming that the rate of extinction and areas of Sierra, Nevada, and Placer ongoing. Approximately four recolonization observed over this time counties. Jennings and Hayes (1994) populations (all in California) exist on period accurately reflects the long-term conclude that, based on their re-surveys this national forest (C. Milliron, rates). The documented extinctions of historic locations, 1992, the species California Department of Fish and Game appeared to occur nonrandomly across had been extirpated in a number of (CDFG), in litt. 2002; L. Murphy, USFS, the landscape, are spatially clumped locations by 1992. pers. comm. 2002). Chytrid fungus (see typically, and involve the disappearance The Tahoe National Forest has been Factor C, Disease, below) has been of all or nearly all mountain yellow- conducting some amphibian surveys. documented at one of these populations legged frog populations in a watershed Approximately four or five extant (C. Milliron, in litt. 2002). populations exist in which mountain (R. Knapp in litt. 2002). The Eldorado National Forest: The yellow-legged frog breeding has been colonization sites also appeared to be mountain yellow-legged frog is documented (A. Carlson, USFS, pers. nonrandomly distributed, occurring distributed across the Eldorado National comm. 2002). Extant mountain yellow- primarily in watersheds with large Forest with populations or legged frog populations on the Tahoe mountain yellow-legged frog metapopulations (multiple breeding National Forest have been observed in populations (R. Knapp in litt. 2002). populations within the same basin that both stream and pond habitats. One A recent review of the current status have hydrologic connectivity between of 255 previously documented extant breeding population inhabits an them) within the headwaters and mountain yellow-legged frog locations old mining tailing pond that has been headwater tributaries of several (based on Jennings and Hayes (1994)) restored naturally to a forested wetland watersheds, including the Rubicon throughout its historic range concluded condition with an abundance of River, the South Fork American River, that 83 percent of these sites are no bankside and emergent vegetation (A. the North Fork Cosumnes River, and the longer occupied by this species Carlson, pers. comm. 2002). The largest North Fork Mokelumne River (J. (Davidson et al. 2002). Each national Tahoe National Forest population Williams, USFS, in litt. 2002). forest and national park is discussed observed in recent surveys consists of individually below. fewer than 10 individuals. The species Numerous surveys for mountain Lassen National Forest: Historically, appears to have disappeared from a yellow-legged frogs have been mountain yellow-legged frogs occurred significant number of historic locations conducted on this national forest by the on the Lassen National Forest within within the Tahoe National Forest and is USFS, the CDFG, and several multiple watersheds, including Butte in low abundance where it still persists contractors between 1990 and 2002. Creek, the West Branch Feather River, (A. Carlson, pers. comm. 2002). Reproducing populations have been and the Middle Fork Feather River (M. Lake Tahoe Basin Management Unit: found at a variety of locations in high McFarland, in litt. 2002). The last Historic sightings of the mountain elevation areas of this national forest. confirmed mountain yellow-legged frog yellow-legged frog in the Lake Tahoe Surveys for amphibians within the sighting on the Lassen National Forest Basin Management Unit are numerous, Eldorado National Forest in 1992 was made in 1966 in the area of Snag indicating that the species was resulted in no detections of mountain Lake in the West Branch Feather River abundant in the Lake Tahoe area (J. yellow-legged frogs, though this may be watershed. Since 1993, the Lassen Reiner, USFS, pers. comm. 2002). a function of the limited area and National Forest has conducted or Today, only one known population of habitat type that was surveyed (Martin funded informal and formal systematic mountain yellow-legged frogs remains 1992). Jennings and Hayes (1994) amphibian surveys to assess the relative on this national forest, although in 1997, indicate both extirpated populations distribution and abundance of the USFS saw evidence of limited and extant populations on the Eldorado amphibian species, including the breeding in the Desolation Wilderness National Forest. Intensive surveys by mountain yellow-legged frog. On the (J. Reiner, pers. comm. 2002; J. Reiner CDFG and USFS in 2001 and 2002 Lassen National Forest, mountain and M. Schlesinger, USFS, in litt. 2000). resulted in an estimated 18 extant yellow-legged frogs have not been The known population is small, as some populations or metapopulations of detected or confirmed during any of adults were seen in 1999 but were not mountain yellow-legged frogs on the these surveys (M. McFarland in litt. detected during 2002 surveys, though Eldorado National Forest, although both 2002). larvae were detected. The habitat at this the mean number of populations and Plumas National Forest: Based on site is a meadow and stream complex population size are generally low resurvey efforts, Jennings and Hayes that is large (approximately 24 ha (60 relative to historic reports (J. Williams, (1994) noted that the mountain yellow- ac)) and in good condition (J. Reiner, in litt. 2002). Currently, approximately legged frog was extirpated at a number pers. comm. 2002). four populations exist with between 25 of locations in the Plumas National Humboldt-Toiyabe National Forest: and 50 mountain yellow-legged frogs; Forest. As survey efforts continue by the Only the westernmost portion of the these are the largest populations on the Plumas National Forest, more mountain Humboldt-Toiyabe National Forest is Eldorado National Forest (J. Williams, in yellow-legged frog populations are being within the historic range of the litt. 2002).

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Stanislaus National Forest: A 1992 frog habitat. The mountain yellow- Jennings and Hayes (1994) indicated survey (Martin 1992) in the Stanislaus legged frog had declined by that the mountain yellow-legged frog National Forest located mountain approximately 80 percent from the has become extirpated at a number of yellow-legged frogs at only 2 of 16 locations documented by the 1924 study historical locations in the Sierra locations surveyed, and at these (Drost and Fellers 1996). A distribution National Forest. Knapp and Matthews locations, the numbers of adults map of mountain yellow-legged frogs (2000) report on mountain yellow- detected were small (under five). produced by Jennings and Hayes (1994) legged frog population declines Jennings and Hayes (1994) indicate that also documents extinctions and associated with fish stocking within the the species has been extirpated from a indicates a population decline of this John Muir Wilderness Area of the Sierra number of historic locations. There are species from Yosemite National Park. National Forest (see Factor C, Disease, approximately 80 extant populations of Colwell and Beatty (2002) surveyed 35 below). In 1995 and 1996, Knapp and mountain yellow-legged frogs on the lakes with appropriate mountain Matthews (2000) surveyed 669 lakes, Stanislaus National Forest; of these, yellow-legged frog habitat within the ponds, and other water bodies in the only about 8 appear to have more than Tuolumne and Merced River drainages John Muir Wilderness Area. Mountain 10 adults, and only 2 populations are of Yosemite National Park in 1992 and yellow-legged frog adults were found in known to have 25 to 30 adults (L. 1993; only 3 lakes were found to have 4 percent of these water bodies, and frog Conway, USFS, pers. comm. 2002). mountain yellow-legged frogs. larvae in 3 percent (Knapp and Mathews Yosemite National Park: From 1914 to Currently in Yosemite National Park, 2000). In 2002, Knapp conducted 1920, Grinnell and Storer conducted a 251 mountain yellow-legged frog sites resurveys at the 28 water bodies that biological survey along a transect across exist, most of which occur within 23 had been occupied by mountain yellow- the Sierra Nevada. They documented different basins that have multiple legged frogs in 1997, and also at 118 of mountain yellow-legged frogs at 14 sites breeding populations with habitat that the 641 sites where frogs were not throughout Yosemite National Park and is connected hydrologically, so that the detected in 1997. Knapp found no noted the species was abundant in this populations in each basin function as a change in mountain yellow-legged frog area. Numerous frogs were found in metapopulation (R. Knapp in litt. 2002). status at 39 percent of these 28 lakes and streams at high elevations Six sites have populations with over 100 previously occupied water bodies, but (Grinell and Storer 1924). ‘‘Hundreds of adult mountain yellow-legged frogs found that the frogs at 61 percent of the frogs’’ were found at Young Lake and each, 1 site has a population with 28 previously occupied sites had gone frogs were ‘‘very numerous’’ at Westfall between 51 and 100 adults, and 41 sites extinct, while colonization had occurred Meadow (Camp1915, as cited in Drost have populations between 10 and 50 at 10 percent of 118 previously and Fellers 1994). Large numbers of adults each. In addition, 203 sites have unoccupied sites (R. Knapp in litt. specimens were collected; for example, fewer than 10 adults each. Of the 251 2002). 25 were taken at Vogelsang Lake mountain-yellow legged frog sites in the Although not all potential mountain (Grinnell 1915, as cited in Drost and park, evidence of breeding has been yellow-legged frog habitats have been Fellers 1994). found in 71 populations. surveyed within the Sierra National The mountain yellow-legged frog was Inyo National Forest: Jennings and Forest, approximately six documented at several additional Hayes (1994) document the extirpation subwatersheds have extant locations in Yosemite National Park of some mountain yellow-legged frog metapopulations (H. Eddinger, USFS, in from 1957 to 1960 (Heller 1960). At populations from the Inyo National litt. 2002). These subwatersheds are in Johnson Lake, Mullally and Forest. In 1994, 15 known locations had the upper headwaters of the South Fork Cunningham (1956) reported a mountain yellow-legged frog Merced River, South Fork San Joaquin mountain yellow-legged frog population populations (Parker 1994). Currently, 7 River, and North Fork Kings River. They decline between 1950 and 1955, though basins within the Inyo National Forest include the Mono Creek Basin, the Bear they did not quantify the decline. They have known extant mountain yellow- Creek Basin, the Paiute Creek Basin, the attributed this decline to the unusually legged frog populations or populations Humphreys Creek Basin, the Big Creek long and cold winter of 1951–1952. that function as metapopulations (C. Basin, and the Dinkey Creek Basin. Some of Yosemite’s ‘‘densest Milliron, in litt. 2002). Some of these Sequoia and Kings Canyon National aggregations of frogs ever noted’’ by populations are stable, consisting of Parks: Relatively few records exist for Mullally and Cunningham (1956) were several hundred individuals mountain yellow-legged frog prior to in lakes near Ostrander Lake south of representing all age classes (L. Sims, 1955 in the Sequoia and Kings Canyon Glacier Point; they attributed the USFS, in litt. 2002). Chytrid fungus (see National Parks. From 1955 to 1979, the absence of frogs in Ostrander Lake to the Factor C, Disease, below) has been species is known to have occurred in at presence of non-native trout. documented at an additional population least 21 sites scattered throughout Between 1988 and 1991, Bradford et location that is now extinct (C. Milliron, Sequoia and Kings Canyon National al. (1994a) randomly selected and in litt. 2002). Parks, although historic abundance is surveyed four mountain yellow-legged Sierra National Forest: In 1955, not known (Bradford et al. 1994a). In frog populations documented in Mullally and Cunningham (1956) 1978–1979, the headwaters of seven Yosemite between 1955 to 1979. reported encountering mountain yellow- creek systems were surveyed for Although they did not resurvey all of legged frogs along Paiute Creek ‘‘very mountain yellow-legged frogs in the the mountain yellow-legged frog sparingly’’ at approximately 2,300 m national parks. Frogs were found at 27 populations previously reported from (7,700 ft), with frogs becoming more sites greater than 200 m (660 ft) apart within the park, they reported that the abundant at higher elevations. The (Bradford et al. 1994a). A distributional four resurveyed populations were ‘‘densest populations’’ were found map of mountain yellow-legged frogs extirpated (Bradford et al.1994a). In above 3,050 m (10,000 ft) in the produced by Jennings and Hayes (1994) 1992 and 1993, Drost and Fellers (1996) Humphrey’s Basin area, and a ‘‘great indicates numerous historic sightings revisited 38 of the original 40 sites many, including tadpoles’’ were noted and collections of the species within surveyed by Grinnell and Storer from at and near Pine Creek Pass, with frogs both national parks, as well as 1914 to1920, and surveyed other sites also seen at Golden Trout and numerous extinctions. The species was with potential mountain yellow-legged Desolation Lakes. already noted to have disappeared from

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approximately half of previously All of the recent mountain yellow- condition, the marked separation from occupied locations in Sequoia and legged frog sightings from the Sequoia other populations. Kings Canyon Parks by the late 1980s National Forest have been of single frogs The range of the mountain yellow- (Bradford et al. 1994a). On the basis of or very small populations. In 1992, legged frog is divided by a natural surveys, Bradford et al. (1994a) estimate mountain yellow-legged frogs were not geographic barrier, the Tehachapi that mountain yellow-legged frogs have detected during amphibian surveys Mountains, which geographically been extirpated from half of their conducted at 17 sites in Sequoia isolates the populations in the southern historic locations in Sequoia and Kings National Forest (Martin 1992). The Sierra Nevada from those in the Canyon National Parks. For example, species appears to be severely reduced mountains of southern California. The Fellers (1994) surveyed in Sequoia and in numbers and range in the Sequoia distance of the geographic separation is Kings Canyon National Parks and did National Forest. about 225 km (140 mi). The geographic separation of the Sierra Nevada and not detect the mountain yellow-legged Distinct Vertebrate Population Segment frog in the Kaweah watershed where the southern California mountain yellow- species was located historically. Under the Act, we must consider for legged frogs was recognized in the In 1997, Knapp and Matthews (2000) listing any species, subspecies, or, for earliest description of the species by surveyed 1,059 lakes, ponds, and other vertebrates, any distinct population Camp (1917), who treated specimens water bodies in Kings Canyon National segment (DPS) of these taxa if there is from the two areas as separate Park. Mountain yellow-legged frog sufficient information to indicate that subspecies of R. boylii. Camp (1917) adults were found in 31 percent of these such action may be warranted. To described the two subspecies based on water bodies, and frog larvae in 20 implement the measures prescribed by differences in their biogeography and percent (Knapp and Mathews 2000). the Act, we, along with the National morphology. Marine Fisheries Service (National Some significant frog populations Ziesmer (1997) analyzed vocalizations Oceanic and Atmospheric remain in Sequoia and Kings Canyon of mountain yellow-legged frogs from 86 Administration–Fisheries), developed a National Parks, but extensive declines locations in Alpine and Mariposa joint policy that addresses the counties in the Sierra Nevada, and have been described. In 2002, Knapp (in recognition of DPSs for potential listing vocalizations of mountain yellow-legged litt. 2002) resurveyed 274 water bodies actions (61 FR 4722). The policy allows frogs from 23 locations in the San occupied by mountain yellow-legged for a more refined application of the Act Jacinto Mountains of Riverside County frogs in 1997, and he also resurveyed that better reflects the biological needs in southern California. The 626 of the 785 sites where frogs were of the taxon being considered, and vocalizations of Sierra Nevada frogs not detected in 1997. Knapp found no avoids the inclusion of entities that do differed from those of southern change in status at 60 percent of the 274 not require the Act’s protective California frogs in pulse rate, harmonic previously occupied sites, but found measures. structure, and dominant frequency. that 39 percent of the 274 previously Under our DPS Policy, we use two Ziesmer (1997) concluded that the occupied sites had gone extinct, while elements to assess whether a population differences in vocalization supported colonization had occurred at 7 percent segment under consideration for listing the hypothesis that mountain yellow- of 626 previously unoccupied sites. may be recognized as a DPS. The legged frogs from the Sierra Nevada and Currently in Sequoia and Kings elements are: (1) the population southern California may represent Canyon National Parks, 507 mountain segment’s discreteness from the separate species. yellow-legged frog sites are known, most remainder of the species to which it Genetic analyses support the of which occur within 36 different belongs; and (2) the significance of the discreteness of the mountain yellow- basins that have multiple breeding population segment to the species to legged frog populations in southern populations that are hydrologically which it belongs. If we determine that California from those in the Sierra connected, so that the populations a population segment being considered Nevada. In an allozyme (genetic) study within each basin function as a for listing is a DPS, then the level of that compared mountain yellow-legged metapopulation. Fifty-four sites have threat to the population is evaluated frogs from the central Sierra Nevada populations of more than 100 adult based on the five listing factors with those from southern California, a mountain yellow-legged frogs, 25 sites established by the Act to determine if fairly significant genetic difference was have populations between 51 and 100 listing it as either threatened or found between the two populations (D. adults, 132 sites have populations endangered is warranted. Green, McGill University, in litt. 1993). between 10 and 50 adults, and 296 sites Discreteness. Under our DPS Policy, a However, because there were no frog have fewer than 10 adults. Of the 507 population segment of a vertebrate samples from the southern Sierra mountain yellow-legged frog sites in species may be considered discrete if it Nevada for comparison, it was not clear Sequoia and Kings Canyon National satisfies either one of the following two whether the difference reflected two Parks, breeding evidence has been conditions: (1) it is markedly separated ends of a cline (a character gradient), or found at 259 populations (R. Knapp in from other populations of the same distinctions between the Sierra Nevada litt. 2002). taxon as a consequence of physical, and southern California populations. Sequoia National Forest: Jennings and physiological, ecological, or behavioral Thus, because the data set was Hayes (1994) indicate that the mountain factors. Quantitative measures of genetic incomplete, Green (in litt., 1993) yellow-legged frog has been extirpated or morphological discontinuity may interpreted the results cautiously. from a number of historical locations in provide evidence of this separation; or A phylogenetic analysis of the Sequoia National Forest. Mountain (2) it is delimited by international mitochondrial deoxyribonucleic acid yellow-legged frogs were collected on governmental boundaries within which (DNA) sequences of the mountain several historic locations of the Kern significant differences in control of yellow-legged frog was performed Plateau in Sequoia National Forest exploitation, management of habitat, throughout its distribution (Macey et al. (Jennings and Hayes 1994). Today, two conservation, status, or regulatory 2001). This study concluded that there known extant populations exist on the mechanisms exist. The proposed DPS, are two major genetic lineages of the Sequoia National Forest (S. Anderson, the Sierra Nevada mountain yellow- mountain yellow-legged frog (inclusive USFS, in litt. 2002). legged frog, is based on the first of the Sierra Nevada populations and

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the southern California populations), into small meadow streams at higher FR 44382). The geographic isolation of with populations in the Sierra Nevada elevations (Zweifel 1955; Mullally the Sierra Nevada population from the falling into three distinct groups and the 1959). In contrast, Sierran frogs are most mountain yellow-legged frogs in fourth being the southern California abundant in high-elevation lakes and southern California prevents genetic population (Macey et al. 2001). Though slow-moving portions of streams interchange between these populations. three genetic lineages of mountain (Zweifel 1955; Mullally and Conclusion. We evaluated the Sierra yellow-legged frogs have been identified Cunningham 1956), habitat that is Nevada population of the mountain in the Sierra Nevada, more genetic distinct from the canyons of southern yellow-legged frog to determine whether sampling is needed to delineate specific California’s arid mountain ranges, it meets the definition of a DPS, boundaries of the three genetic lineages which are inhabited by the southern addressing discreteness and significance before they are treated or managed as California DPS of the mountain yellow- as required by our policy. We conclude separate units (Macey et al. 2001). legged frog. that the Sierra Nevada population of the Therefore, this finding treats the three Significance. Under our DPS Policy, mountain yellow-legged frog is discrete genetic lineages of the mountain yellow- once we have determined that a from the southern California population, legged frog in the Sierra Nevada as one population segment is discrete, we on the basis of their geographic DPS, discrete from the mountain consider its biological and ecological separation, differences in vocalization, yellow-legged frog DPS in southern significance to the larger taxon to which differences between their habitats, and California. it belongs. This consideration may apparent genetic differences. We The biogeographic fragmentation include, but is not limited to: (1) conclude that the Sierra Nevada within the Sierra Nevada population of Evidence of the persistence of the population of the mountain yellow- mountain yellow-legged frogs occurs discrete population segment in an legged frog is significant because the between Kings Canyon National Park ecological setting that is unusual or loss of the species from the Sierra and a region slightly north of Yosemite unique for the taxon; (2) evidence that Nevada would result in a significant National Park, allowing for the central loss of the population segment would reduction in the species’ range and its and northern Sierra Nevada populations result in a significant gap in the range population numbers, and would to share more genetic similarities than of the taxon; (3) evidence that the constitute the loss of a genetically the southern Sierra Nevada and population segment represents the only discrete population that differs southern California populations (Macey surviving natural occurrence of a taxon markedly from the southern California et al. 2001). In fact, this study indicates that may be more abundant elsewhere as population of mountain yellow-legged that the southern Sierran group (largely an introduced population outside its frogs. Because the population segment in Fresno County) may be more closely historic range; or (4) evidence that the meets both the discreteness and related to the southern California discrete population segment differs significance criteria of our DPS policy, mountain yellow-legged frogs than with markedly from other populations of the the Sierra Nevada portion of the those in the central and northern Sierra species in its genetic characteristics. mountain yellow-legged frog’s range Nevada (Macey et al. 2001). This We have found substantial evidence qualifies for consideration for listing. research suggests that the initial that all but one (there are no introduced An evaluation of the level of threat to divergence between the northern and populations of mountain yellow-legged the DPS based on the five listing factors southern populations of mountain frogs outside of its historic range) of established by the Act follows. yellow-legged frogs occurred 2.2 million these significant factors are met by the Previous Federal Action years before present. Within each of population of mountain yellow-legged these groups, Macey et al. (2001) have frogs in the Sierra Nevada. Furthermore, On February 10, 2000, we received a detected a similar pattern of divergence it is significant because a major petition, dated February 8, 2000, from that suggests the northern Sierra Nevada reduction in abundance of the species as the Center for Biological Diversity and and central Sierra Nevada mountain a whole would occur if the Sierra Pacific Rivers Council to list the Sierra yellow-legged frog populations diverged Nevada population were extirpated. The Nevada population of the mountain 1.5 million years before present, and the extinction of the Sierra Nevada yellow-legged frog as endangered. The southern Sierra Nevada and the population of the mountain yellow- petitioners stated that the Sierra Nevada southern California mountain yellow- legged frog would result in the loss of population of the mountain yellow- legged frog populations diverged from a genetic entity, a reduction in the legged frog qualifies for listing under each other approximately 1.4 million geographic range of the species, a loss our DPS Policy. On October 12, 2000, years before present. Today, these 4 of the species persistence in a setting we published a 90-day finding on that groups are isolated by arid valleys; this ecologically unique relative to the petition in the Federal Register (65 FR isolation is most pronounced between ecological setting of the southern 60603) concluding that the petition southern California and the southern California population, and a reduction presented substantial scientific or Sierra Nevada. The biogeographic in the number of breeding populations. commercial information to indicate that pattern of genetic divergence as detected As discussed above, the Sierra Nevada the listing of the Sierra Nevada in the mountain yellow-legged frogs of population appears to be genetically population of the mountain yellow- the Sierra Nevada has also been distinct from the southern California legged frog may be warranted; we also observed in four other reptiles and population of mountain yellow-legged requested information and data amphibians, suggesting a common event frogs. The mountain yellow-legged frogs regarding the species. that fragmented their ranges (Macey et of the Sierra Nevada comprise the main This 12-month finding is made in al. 2001). distribution of the species at the accordance with a court order which Sierran frogs and southern California northern and central limits of the requires us to complete a finding by mountain yellow-legged frogs also differ species’ range. Loss of the Sierra Nevada January 10, 2003 (Center for Biological ecologically in the types of aquatic population would be significant as it Diversity and Pacific Rivers Council v. habitat they occupy. Mountain yellow- would eliminate the species from the Norton and Jones) (No. C 01–2106 SC). legged frogs in southern California are majority of its range and would reduce This notice constitutes the 12-month typically found in steep gradient the species to fewer than 10 small finding for the February 10, 2000, streams, even though they may range isolated sites in southern California (50 petition.

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Summary of Factors Affecting the ecosystems and adjacent upland areas increase as California’s human Species that directly affect them) began in the population increases (USFS 2001). Observational data indicate livestock Section 4 of the Act and regulations mid-1700s with the European settlement negatively impact mountain yellow- (50 CFR part 424) promulgated to of California (Menke et al. 1996). legged frog populations by altering frog implement the listing provisions of the Following the gold rush of the mid- habitat and trampling individuals (R. Act describe the procedures for adding 1800s, grazing rose to a level that Knapp, in litt. 1993a, 1993b, 1994, 2002; species to the Federal lists. We may exceeded the carrying capacity of the Jennings 1996; A. Carlson, pers. comm. determine a species (which is defined in available range and caused significant 2002; USFS 2002; V. Vrendenburg, in section 3 of the Act as including any impacts to meadow and riparian ecosystems (Meehan and Platts 1978; litt. 2002). subspecies of fish or wildlife or plants, Livestock grazing causes changes in and any distinct population segment of Menke et al. 1996). From 1870 to 1908, within the range of the mountain wetland systems, including meadows, any species of vertebrate fish or wildlife streams, and ponds; modifies mountain which interbreeds when mature) to be yellow-legged frog in the high Sierra Nevada, meadows were converted to yellow-legged frog habitat by removing endangered or threatened because of overhanging banks that provide shelter; one or more of the five factors described summer rangelands for grazing cattle, sheep, horses, goats, and in some areas and contributes to the siltation of in section 4(a)(1) of the Act. These breeding ponds. Pond siltation may factors, and their application to the pigs; however, the alpine areas were mainly grazed by sheep (Beesley 1996; decrease the survivorship of Sierra Nevada DPS of the mountain overwintering larvae, subadults, and yellow-legged frog (mountain yellow- Menke et al. 1996). This practice resulted in the degradation of these adult mountain yellow-legged frogs as legged frog), are as follows: the overwintering habitats need to be A. The present or threatened extremely sensitive areas (Menke et al. 1996). deep enough so that the entire water destruction, modification, or column does not freeze and underwater In general, livestock grazing within curtailment of its habitat or range. A caves and crevices are available the range of the mountain yellow-legged number of hypotheses, including habitat (Bradford 1983; Pope 1999a). loss, have been proposed for recent frog was at a high but undocumented Grazing of livestock in riparian areas global amphibian declines (Bradford et level until the establishment of national impacts vegetation in multiple ways, al. 1993; Corn 1994; Alford and parks (beginning in 1890) and national including: soil compaction, which Richards 1999). Habitat destruction, forests (beginning in 1905). Within increases runoff and decreases water however, does not appear to be the established national parks, grazing by availability to plants; herbage removal, primary factor leading to the decline of cattle and sheep was replaced by that of which promotes increased soil the mountain yellow-legged frog. The packstock, such as horses and burros. temperatures and evaporation rates at mountain yellow-legged frog occurs at Within established national forests, the the soil surface; and direct physical high elevations in the Sierra Nevada, amount of livestock grazing was damage to the vegetation (Kauffman and which have not had the types or extent gradually reduced and better Krueger 1984; Cole and Landres 1996; of large-scale habitat conversion and documented, and the types of animals Knapp and Matthews 1996). Streamside disturbances which have occurred at shifted, with reductions in sheep and vegetation protects and stabilizes lower elevations (Bradford et al. 1993; increases in cattle and packstock. In streambanks by binding soils to resist Knapp 1996; Knapp and Matthews general, livestock grazing within the erosion and to trap sediment (Chaney et 2000). Large scale habitat conversion national forests has continued with al. 1990). A study by Kauffman et al. has not been identified within the range gradual reductions since the 1920s, (1983) indicated that livestock grazing of this species; thus, direct habitat except for an increase during World War may have weakened the streambank destruction or modification associated II. Continuing decreases, motivated by structure through trampling and with intensive human activities, as concern towards resource protection, removal of vegetation, thereby measured by urban or agricultural land conflicts with other uses, and promoting conditions for erosion. use within the mountain yellow-legged deteriorating range conditions, Removal of vegetative cover within frogs’ range, has not been implicated in continued from the 1950s through the mountain yellow-legged frog habitat the decline of this species (Davidson et early 1970s but still exceeded decreases available habitat, exposes al. 2002). However, other human sustainable grazing capacity in many frogs to predation (R. Knapp, in litt. activities have played a role in the areas (Menke et al. 1996; University of 1993b), and increases the threat of modification of mountain yellow-legged California (UC) 1996a). Grazing dessication (Jennings 1996). Grazing frog habitat. These include livestock management that is more sensitive to may result in changes to vegetation grazing, non-native fish introductions riparian areas has been implemented composition, resulting in an increased (see Predation, Factor C, below), timber and continues to increase since the density of forested stands and the management, road construction and 1970s (UC 1996a). expansion of trees into areas that were maintenance, recreation, water Packstock grazing is the only grazing formerly treeless (Cole and Landres diversions, fire management activities, currently permitted in the Sierra Nevada 1996). and introduction of environmental national parks. Packstock grazing also is Livestock grazing can cause a nutrient contaminants (see Other, Factor E, permitted in national forests within the loading problem due to urination and below). These activities have modified Sierra Nevada. However, there has been defecation in or near the water, and can habitat in ways that have fragmented very little monitoring of the impacts of elevate bacteria levels in areas where and isolated mountain yellow-legged packstock use in this region (Menke et cattle are concentrated near water frog populations, and thereby, may have al. 1996). Use of packstock in the Sierra (Meehan and Platts 1978; Stephenson caused or contributed to the decline of Nevada increased since World War II as and Street 1978; Kauffman and Krueger this DPS (Bradford et al. 1993). a result of increased road access and 1984). The nutrient status of streams can increases in leisure time and disposable markedly influence the growth of Grazing income (Menke et al. 1996). Demand for microflora and microfauna and directly Grazing of livestock in Sierra Nevada packstock use and recreational riding in and indirectly affect many other meadows and riparian areas (aquatic the Sierra Nevada are projected to characteristics of the stream biota

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(Lemly 1998). Growth of filamentous range of the mountain yellow-legged downstream of dams, and act as barriers bacteria on the bodies and gills of frog has contributed to the decline of to movements by dispersing juvenile aquatic insects has been documented in this species (see Predation, Factor C, and migrating adult amphibians association with nutrient loading in below). The recreational impact of (Jennings 1996). Where dams act as livestock use pastures, along with anglers at high mountain lakes has been barriers to mountain yellow-legged frog significantly lower densities of insects severe in the Sierra Nevada, with most movement, they would effectively at downstream sites. In laboratory and regions reporting a level of use greater prevent genetic exchange between field studies, aquatic insects with this than that which the fragile lakeshore populations and the recolonization of bacterial growth experienced extensive environments can withstand (Bahls sites. Water diversions that remove mortality. This indicates that elevated 1992). water from mountain yellow-legged frog bacteria levels associated with livestock Recreation may threaten all life stages habitat may adversely impact breeding use can negatively influence stream of the mountain yellow-legged frog success and adult survivorship if the insect populations (Lemley 1998). through direct disturbance resulting diversion results in a lowering of the Adverse effects to aquatic insects within from trampling by humans, packstock, water level to the extent that the entire the range of the mountain yellow-legged or vehicles, including off-highway water column freezes in the winter, or frog could result in a lowered prey vehicles; harassment by pets; and to the extent that the habitat is rendered availability, possibly increasing associated habitat degradation (Cole and dry. These factors are likely to have intraspecific competition for limited Landres 1996; USFS 2001). Studies have contributed to the decline of mountain resources. not been conducted to determine yellow-legged frogs and probably Throughout the range of the mountain whether recreational activities are continue to pose a risk to the species. yellow-legged frog in the Sierra Nevada contributing to the decline of the approximately 79 currently active mountain yellow-legged frog, and Roads and Timber Harvest grazing allotments exist on USFS- recreation has not been implicated as a Any activity that severely alters the administered lands. Of these grazing cause of major decline of the mountain terrestrial environment, including road allotments, at least 29 have extant yellow-legged frog. construction and timber harvest, is mountain yellow-legged frog likely to result in the reduction and Dams and Water Diversions populations within them. An estimated extirpation of amphibian populations in 13 percent of the approximately 210 Dams and water diversions have the Sierra Nevada (Jennings 1996). Most known mountain yellow-legged frog altered aquatic habitats in the Sierra of the mountain yellow-legged frog populations, or populations that Nevada (Kondolf et al. 1996). Numerous populations are in areas such as function as metapopulations, on Sierra reservoirs have been constructed within national parks or designated wilderness Nevada national forests occur within the range of the mountain yellow-legged areas where timber is not harvested active grazing allotments. Many of the frog. These include Huntington Lake, (Bradford et al. 1994a; Drost and Fellers mountain yellow-legged frog Florence Lake, Lake Thomas A. Edison, 1996; Knapp and Matthews 2000). Some populations in the Sierra Nevada that Saddlebag Lake, Convict Lake, Cherry of these populations, and others outside occur within active grazing allotments Lake, and other reservoirs associated of these areas, are located at too high an are small. These populations may be with Hetch Hetchy, Upper and Lower altitude for timber to be harvested, so more vulnerable to extirpation as a Blue Lakes, Lake Aloha, Silver Lake, this activity is not expected to affect the result of grazing-induced habitat Hell Hole Reservoir, French Meadow majority of extant mountain yellow- modification, and if extirpated they Reservoir, Lake Spaulding, and others. legged frog populations. There are some might not be recolonized in situations The extent of the impacts that these mountain yellow-legged frog where they are isolated from other projects have had on the mountain populations in areas where timber populations and lack habitat yellow-legged frog is not known. The harvests have occurred in the past and connectivity to potential source construction of dams probably has others where it may occur in the future. populations. affected mountain yellow-legged frogs There are also roads within the range of In the 60-Lakes Basin of Kings Canyon in the Sierra Nevada by altering their the mountain yellow-legged frog; National Park, packstock use is habitat and movements, and also by however, neither of these factors has regulated in wet meadows to protect altering the distribution of predators been implicated as an important mountain yellow-legged frog breeding (reservoirs are often stocked with non- contributor to the decline of this species habitat in bogs and lakeshores from native fish species that incidentally prey (Jennings 1996). trampling and associated degradation on mountain yellow-legged frogs (See Fire Management Activities (V. Vredenburg, in litt. 2002; H. Werner, Predation, Factor C, below)). Mountain NPS, in litt. 2002). yellow-legged frogs cannot live in or Mountain yellow-legged frogs are move through the exposed shorelines generally found at high elevations in Recreation created by reservoirs, nor can they wilderness areas and national parks Recreation is the fastest growing use successfully reproduce in these where vegetation is sparse and fire of national forests. As such, its impacts environments with predatory fishes suppression activities are implemented on the mountain yellow-legged frog are unless there are shallow side channels infrequently. Potential impacts to the likely to continue and to increase or disjunct pools that are free of species resulting from fire management (USDA 2001). Recreational activities predatory fishes (Jennings 1996). activities include: Water drafting (taking take place throughout the Sierra Nevada Dams may alter the temperature and of water) from occupied ponds and and have significant negative impacts sediment load of the rivers they lakes, resulting in direct mortality or on several plant and animal species and impound (Cole and Landres 1996). rendering the habitat unsuitable for their habitats (USDA 2001a). To further Dams, water diversions, and their reproduction and survivorship; recreational opportunities and angling associated structures can alter the construction of fuel breaks either by success, non-native trout stocking natural flow regime with unseasonal hand or heavy equipment, potentially programs in the Sierra Nevada started in and fluctuating releases of water, create resulting in erosion and siltation of the late 19th Century (Bahls 1992; Pister habitat conditions unsuitable for native habitat; fire suppression with water 2001). Trout stocking throughout the amphibians both upstream and applications or fire retardants; and

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increased human activity in the area, dams, water diversions, roads, timber 1992; Feldman and Wilkinson 2000; V. potentially disrupting mountain yellow- harvests, and fire management activities Vredenburg et al. (in press)). legged frog behavior. may be factors of secondary importance Predation by introduced trout is the Fire retardant chemicals contain in the decline of the mountain yellow- best-documented cause of the decline of nitrogen compounds and/or surfactants legged frog and the modification of its the Sierra Nevada mountain yellow- (a subset of chemical additives usually habitat (Jennings 1996). legged frog, because it has been used to facilitate application). B. Overutilization for commercial, repeatedly observed that non-native Laboratory tests of these chemicals have recreational, scientific, or educational fishes and mountain yellow-legged frogs shown that they can cause mortality in purposes. There is no known rarely co-exist (Grinnell and Storer fishes and aquatic invertebrates by commercial market for mountain 1924; Needham and Vestal 1938; releasing surfactants and ammonia yellow-legged frogs, nor are there Mullally and Cunningham 1956; Cory when they are added to water (Hamilton documented recreational or educational 1962a, 1963; Bradford 1989; Bradford et al. 1996), and similar effects are likely use for mountain yellow-legged frogs, and Gordon 1992; Bradford et al. 1993, on amphibians. Therefore, if fire although it is likely that they have been 1994a, 1998; Drost and Fellers 1996; retardant chemicals were dropped in or handled by curious members of the Jennings 1996; Knapp 1996; Knapp and near mountain yellow-legged frog public, used as bait by anglers, and Matthews 2000; Knapp et al. 2001; V. habitat, they could have negative effects collected as pets. The mountain yellow- Vredenburg et al., (in press); USFS on individuals. legged frog does not appear to be undated). The body of scientific In some areas within the range of the particularly popular among amphibian research on the distributions of mountain yellow-legged frog, long-term and reptile collectors; however, Federal introduced trout and mountain yellow- fire suppression has changed forest listing could raise the value of the legged frogs over time has conclusively structure and conditions where fire animals within wildlife trade markets demonstrated that introduced trout have severity and intensity are higher and increase the threat of unauthorized negatively impacted mountain yellow- (McKelvey et al. 1996). Prescribed fire collection above current levels (K. legged frogs over much of the Sierra has been used by land managers to McCloud, Service, pers. comm. 2002). Nevada (Bradford 1989; Bradford et al. achieve various silvicultural objectives, Even limited interest in the species 1993, 1994a, 1998; Knapp 1994, 1996; including the reduction of fuel loads. In could pose a serious threat to this Drost and Fellers 1996; Knapp and some systems, fire is thought to be animal. Matthews 2000; Knapp et al. 2001). important in maintaining open aquatic Scientific research may cause stress to Mountain yellow-legged frogs and trout and riparian habitats for amphibians mountain yellow-legged frogs through (native and non-native) do co-occur at (Russel et al. 1999). But severe and disturbance, including disruption of the some sites, but these co-occurrences intense wild fires may reduce the ability species’ behavior, handling individuals, probably are mountain yellow-legged of amphibians to survive such a fire. and injuries associated with marking frog populations that would have However, amphibians display adaptive and tracking individuals. Scientific negative population growth rates in the behavior that may minimize mortality research has also resulted in the death absence of immigration (Bradford et al. from fire, by taking cover in wet habitats of numerous individuals through the 1998; Knapp and Matthews 2000). Non- or taking shelter in subterranean collection of museum specimens native fish stocking programs have been burrows, though the moist and (Zweifel 1955; Jennings and Hays 1994). recognized to have negative ecological permeable skin of amphibians increases However, this is a relatively minor implications because non-native fish eat their susceptibility to heat and threat. Of greater concern are native aquatic flora and fauna, including dessication (Russel et al. 1999). Neither researchers contributing to the spread of amphibians and invertebrates (Bahls the direct nor indirect effects of pathogens via clothing and sampling 1992; Erman 1996; Matthews et al. 2001; prescribed fire or wildfire on the equipment as they move between water Pilliod and Peterson 2001; Schindler et mountain yellow-legged frog have been bodies and populations (Bradford 1991; al. 2001; Moyle 2002). studied, but because the species Bradford et al. 1994a; Fellers et al. Prior to extensive trout planting generally occupies high elevation 2001). Given the uncertainty programs in the late 19th Century habitat, fire is not a likely risk to this surrounding the potential for through the present, most streams and species in much of its range. researchers to contribute to the spread lakes in the Sierra Nevada at elevations In summary, historic grazing activities of pathogens, researchers have begun to above 1,800 m (6,000 ft) were without likely modified the habitat of the implement equipment sterilization fishes. The distributions of several mountain yellow-legged frog throughout procedures between survey sites (H. native fish species occur in lower- its range. Although grazing pressure has Eddinger, in litt. 2002; R. Knapp, in litt. elevation aquatic habitats around the been significantly reduced from historic 2002; V. Vredenburg, in litt. 2002). For Sierra Nevada (Knapp 1996; Moyle et al. levels, grazing may continue to further discussion concerning the threat 1996; Moyle 2002). The only major contribute to localized degradation and of disease, see Factor C below. exception to the 1,800 m (6,000 ft) loss of suitable habitat, negatively C. Disease or predation. elevational limit for fishes within the affecting mountain yellow-legged frog range of the mountain yellow-legged populations. The effects of recreation, Predation frog in the Sierra Nevada was the upper dams, water diversions, roads, timber Native predators of mountain yellow- reaches of the Kern River where native harvests, and fire management activities legged frogs include the mountain garter fish such as the Little Kern golden trout on the mountain yellow-legged frog are snake (Thamnophis elegans elegans), (Oncorhynchus mykiss whitei) evolved not well studied, and though they may valley garter snake (T. sirtalis fitchi), (Moyle 2002). Natural barriers have negatively affected mountain Brewer’s blackbird (Euphagus prevented fish from colonizing the yellow-legged frogs and their habitat, cyanocephalus), Clark’s nutcrackers higher elevation headwaters of the they have not been implicated as (Nucifraga columbiana), coyotes (Canis Sierra Nevada watershed (Moyle et al. primary factors in the decline of this latrans), and black bear (Ursus 1996). species (Bradford et al. 1993; Bradford americanus) (Camp 1917; Grinnell and With the Gold Rush and its associated et al. 1994a; Jennings 1996; Knapp and Storer 1924; Mullally and Cunningham increase in human habitation, habitat Matthews 2000). However, recreation, 1956; Bradford 1991; Jennings et al. alteration, fish distribution and species

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composition began to change affected by different fish stocking 1991; Drost and Fellers 1996). An dramatically in high elevation lakes and regimes, watersheds with differing trout explanation suggested for recent streams (Moyle et al. 1996). Some of the distributions, and individual water mountain yellow-legged frog population first practitioners of trout stocking in the bodies with varying fauna assemblages declines from fishless waters in the Sierra Nevada were the Sierra Club, (Knapp and Matthews 2000). The Knapp Sierra Nevada is the isolation and local sportsmen’s clubs, private citizens, and Matthews (2000) study on the fragmentation of remaining populations and the U.S. military (Knapp 1996; effects of introduced fishes on the by introduced fishes in the streams, Pister 2001). As more hatcheries were mountain yellow-legged frog in the which once provided the mountain built and distribution of non-native fish Sierra and Inyo National Forests’ John yellow-legged frog with dispersal and became better organized under State Muir Wilderness indicated 65 percent of recolonization routes (Bradford 1991; agency leadership, trout continued to be water bodies 1 ha (2.5 ac) or larger were Bradford et al. 1993). Based on a survey planted for the purpose of increased stocked with fishes on a regular basis up of 95 basins within Sequoia and Kings angler opportunities and success (Pister through the time of the study. Over 90 Canyon National Parks, Bradford et al. 2001). After World War II, the method percent of the total water body surface (1993) calculated that the introduction of transporting trout to be stocked in area in the John Muir Wilderness in the of fishes into the study area resulted in high elevation areas changed from Sierra and Inyo National Forests is approximately a ten-fold decrease in packstock to aircraft, which allowed occupied by non-native trout (Knapp hydrologic connectivity between stocking in more remote lakes and in and Matthews 2000). All fish stocking populations of mountain yellow-legged greater numbers. It was at this point that was terminated in 1977 in the adjacent frogs. Knapp and Matthews (2000) CDFG began managing the bulk of the Kings Canyon National Park. Knapp and believe that this has generally restricted program, as it does today (Knapp 1996; Matthews (2000) surveyed all lakes and mountain yellow-legged frogs to Pister 2001). ponds, more than 1,700 water bodies, extremely isolated and marginal habitat. Brook trout (Salvelinus fontinalis), for fishes and mountain yellow-legged Trout influenced the isolation and brown trout (Salmo trutta), rainbow frogs. They concluded that a strong fragmentation of mountain yellow- trout (Oncorhynchus mykiss), and other negative correlation exists between legged frog populations and trout species assemblages have been introduced trout and mountain yellow- metapopulations, making them more planted in most streams and lakes of the legged frogs across the landscape, the vulnerable to extirpation from random Sierra Nevada (Knapp 1996; Moyle watersheds, the individual water bodies events (such as disease) than large, 2002). National forests in the Sierra of the study area, and possibly unfragmented metapopulations (Wilcox Nevada have a higher proportion of throughout the Sierra Nevada (Knapp 1980; Hanski and Simberloff 1997; lakes with non-native fish occupancy and Matthews 2000). Consistent with Bradford et al. 1993; Knapp and than do national parks (Knapp 1996). this finding are the results of an analysis Matthews 2000). Given the This is primarily because the NPS of the distribution of mountain yellow- metapopulation structure of the adopted a policy that greatly reduced legged frog larvae that indicates that the mountain yellow-legged frog, these fish stocking within their jurisdictional presence and abundance of larvae are isolated population locations may have boundaries in the late 1970s. Fish reduced dramatically in lakes that have higher extinction rates than colonization stocking was terminated altogether in fish as compared with lakes that were rates because trout prevent successful Sierra Nevada national parks in 1991 never stocked with fish (Knapp et al. recolonization and dispersal to and from (Bahls 1992; Knapp 1996). 2001). these sites (Bradford et al. 1993; Knapp’s (1996) review of previous Several aspects of the mountain Blaustein et al. 1994a; Knapp and trout distribution estimates and other yellow-legged frog’s life history may Matthews 2000). In addition, available data on trout distribution in exacerbate its vulnerability to predation amphibians may not recolonize the Sierra Nevada indicated that and extirpation by non-native trout unoccupied sites following local approximately 63 percent of lakes larger (Bradford 1989; Bradford et al. 1993; extinctions because of physiological than 1 ha (2.5 ac) contain one or more Knapp 1996; Knapp and Matthews constraints; the tendency for non-native trout species, and as many as 2000). Mountain yellow-legged frogs are amphibians, including the mountain 85 percent of lakes larger than 1 ha (2.5 aquatic and are found mainly in lakes. yellow-legged frog, to move only short ac) within national forests currently This increases the probability that they distances; and high site fidelity contain fish. Lakes larger than 1 ha (2.5 will encounter non-native fishes whose (Blaustein et al. 1994a). ac) within Sierra Nevada national parks distribution has been greatly expanded Knapp and Matthews (2000) suggest were estimated to have from 35 to 50 throughout the Sierra Nevada as a result that the predation of mountain yellow- percent non-native fish occupancy, a 29 of fish stocking. The multiple-year legged frogs by fishes as observed by to 44 percent decrease since fish larval stage of the mountain yellow- Grinnell and Storer (1924), and the stocking was terminated (Knapp 1996). legged frog necessitaties their use of documented declines of the 1970s Though data on fish occupancy in permanent water bodies that are deep (Bradford 1991; Bradford et al. 1994a; streams is lacking throughout the Sierra enough so as not to freeze, and so that Stebbins and Cohen 1995), are not the Nevada, Knapp (1996) estimated 60 overwintering adults can avoid oxygen start of the mountain yellow-legged percent of the streams in Yosemite depletion when the water is covered by frog’s decline, but rather the end of a National Park were occupied by trout, ice (Mullally and Cunningham 1956; long decline that started soon after fish despite the curtailment of stocking Bradford 1983; Knapp and Matthews introductions to the Sierra Nevada practices over 25 years ago. Grinnell and 2000). This further restricts larvae to began in the mid-1800s. Knapp and Storer (1924) observed that fish stocking water bodies suitable for and frequently Matthews (2000) note that in Yosemite National Park ‘‘nearly or inhabited by fishes (Knapp 1996) and metapopulation theory (Hanski 1997) quite eliminates the (mountain yellow- isolates mountain yellow-legged frogs to predicts this type of time lag from legged) frogs.’’ fishless marginal habitats (Bradford et habitat modification to population The most spatially comprehensive al. 1993; Knapp and Matthews 2000). extinction. study of introduced fish and mountain Mountain yellow-legged frog Fish-induced declines of the yellow-legged frog distributions populations have also been extirpated at mountain yellow-legged frog may be included an analysis of large landscapes some fishless bodies of water (Bradford reversed in some locations with an

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intensive and focused effort to restore are forced from shallow margins of lakes the Sierra Nevada, chytrid fungus has a fishless conditions (Knapp and and ponds into deeper unfrozen water simple asexual life cycle, and chytrids Matthews 1998, 2000; Knapp et al. where they are vulnerable to predation can generally withstand adverse 2001). Removing fish from lakes with an by non-native fish; (4) adult mountain conditions such as freezing or drought adjacent source population of mountain yellow-legged frogs that co-occur with (Briggs et al. 2002). A research effort is yellow-legged frogs can result in the non-native fish are vulnerable to underway to study the dynamics of this rapid recolonization of the lake by the predation when they are exposed to pathogen and the mountain yellow- species and, over time, may result in these fish, such as when adult legged frog within the Sierra Nevada recovery to conditions similar to lakes mountain-yellow legged frogs (Briggs et al. 2002). Whether adult frogs that had never been stocked (Knapp et overwinter at the bottom of deep water acquire this fungus from tadpoles or al. 2001; Briggs et al. 2002; R. Knapp, bodies; and (5) the introduction of non- whether the fungus is retained through in litt. 2002). Trout removal from several native fish has fragmented mountain metamorphosis is unknown. However, lakes has been successfully yellow-legged frog habitat, isolated the mountain yellow-legged frog may be accomplished in the Sierra National populations from each other, and especially vulnerable to infections of Forest’s John Muir Wilderness. This has generally restricted remaining mountain chytrid fungus as all life stages of the resulted in the natural recolonization yellow-legged frog populations to mountain yellow-legged frog share the and initial recovery of mountain yellow- marginal habitats, thereby increasing the same habitat nearly year round, legged frogs in one of the lakes where likelihood of localized extinctions facilitating the transmission of this trout were removed (R. Knapp, in litt. without the possibility of fungus to individuals at different life 2002). In the other two lakes within this recolonization. stages within a population (Fellers et al. basin where trout were removed, Disease 2001). Survey results from 2000 in mountain yellow-legged frogs were Yosemite and Sequoia-Kings Canyon successfully reintroduced, and there is There have been recent reports from National Parks indicate 24 percent of evidence of reproduction in these around the globe of disease- and the mountain yellow-legged frog translocated populations (R. Knapp, in pathogen-related population declines populations show signs of chytrid litt. 2002). Sequoia and Kings Canyon and mass die offs of amphibians infection (Briggs et al. 2002). In National Parks have initiated a (Bradford 1991; Blaustein et al. 1994b; mountain yellow-legged frogs, chytrid mountain yellow-legged frog restoration Alford and Richards 1999). Mountain fungus has been observed to result in yellow-legged frogs are susceptible to project which employs gill nets and overwinter mortality and mortality diseases such as red-leg disease, caused electrofishing to remove fish from select during metamorphosis (Briggs et al. by the bacterial pathogen Aeromonas lakes and adjacent stream segments at 2002). Effects of chytrid fungus on host hydrophila. This pathogen can cause sites with little to no human visitation populations of the mountain yellow- localized population crashes (Bradford (NPS 2001). However, because of the legged frog are variable, ranging from 1991). Bradford (1991) suggested that cumulative effect of past mountain extinction, persistence with a high level one such outbreak was a result of yellow-legged frog population declines of infection, to persistence with low overcrowding within the mountain (upwards of 80 percent in the 20th levels of infection (Briggs et al. 2002). yellow-legged frog population. Though century), and ongoing population Studies of the microscopic structure of it is opportunistic and successfully tissue and other evidence suggests declines caused by disease or other attacks the immunosuppressed factors, the recolonization of lakes individuals, this pathogen appears to be chytrid fungus caused many of the restored to fishless conditions will grow highly contagious, affecting the recent extinctions in the Sierra National less likely as the number of viable epidermis and digestive tract of Forest’s John Muir Wilderness Area and source populations of mountain yellow- otherwise healthy amphibians (Shotts in Kings Canyon National Park, where legged frogs dwindles (Knapp et al. 1984; Carey 1993; Carey and Bryant 41 percent of the populations went 2001). 1995). Grinnell and Storer (1924) extinct between 1995 and 2002 (R. The best-documented cause of the reported red-legged disease had infected Knapp, in litt. 2002). decline of the mountain yellow-legged some mountain yellow-legged frog Chytrid fungus affecting wild frog frog is the introduction of non-native populations in Yosemite National Park. populations was not documented until fish (Bradford 1989; Bradford et al. In California, chytridiomycosis the late 1990s. Since then, it has been 1993; Knapp and Matthews 2000). In (Batrachochytrium dendrobatidis), more reported in amphibian populations summarizing the effects of non-native commonly known as chytrid fungus, has worldwide (Fellers et al. 2001). We do fish on the mountain yellow-legged frog, been detected in nine amphibian not know how long the mountain it is important to recognize that: (1) The species, including the mountain yellow- yellow-legged frog populations have vast majority of the range of the legged frog (Fellers and Green, pers. been exposed to chytrid fungus. Red-leg mountain yellow-legged frog did not comm., as cited in Briggs et al. 2002; R. disease is typically a secondary evolve with any species of fish as this Knapp, Sierra Nevada Aquatic Research infection following a chytrid infection. frog predominantly occurs in water Laboratory, University of California at If this was also the case in the early bodies above natural fish barriers; (2) Santa Barbara, pers. comm. 2002). 1900s, then it would suggest that what water bodies throughout the range of the Fellers et al. (2001) report the presence Grinnell and Storer (1924) actually were mountain yellow-legged frog have been of several bacteria and chytrid fungus in seeing was chytrid infections (R. Knapp, intensively stocked with non-native larval and recently metamorphosed in litt. 2002). During a visual fish, and where stocking has terminated, mountain yellow-legged frogs from sites examination of mountain yellow-legged self-sustaining fish populations within the Sierra Nevada. Chytrid frog tadpoles preserved between 1993 continue to persist; (3) the multiple year fungus affects the keratinized (horny and 1999, abnormalities attributed to larval stage of the mountain yellow- epidermal tissue) mouth parts and the chytrid fungus were detected on 14 legged frog prevents successful epidermal tissue of larvae and of 36 specimens and no abnormalities recruitment to populations that co-occur metamorphosed mountain yellow- were detected on any of the 43 tadpole with non-native fish because when legged frogs (Fellers et al. 2001). Though specimens collected between 1955 and water bodies ice over in winter, larvae little is known about its life history in 1976 (Fellers et al. 2001). This indicates

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that chytrid fungus infections may be a or if their presence is a recent yellow-legged frog), chytrid currently recent pathogen to affect the mountain phenomenon is uncertain (Fellers et al. appears to have the highest rate of yellow-legged frog, although visual 2001). The susceptibility of amphibians infection relative to other pathogens in detections of chytrid-like abnormalities to pathogens may have recently mountain yellow-legged frog may be neither longlasting nor increased in response to anthropogenic populations. The negative consequences attributable to this fungus (Fellers et al. (human-caused) environmental of chytrid infection to mountain yellow- 2001; V. Vredenburg, in litt. 2002). disruption (Carey 1993; Blaustein et al. legged frog populations may be Since at least 1976, chytrid fungus has 1994b; Carey et al. 1999). This exacerbated by the fragmentation and affected adult Yosemite toads (Green hypothesis suggests that environmental isolation of remaining mountain yellow- and Kagarise Sherman 2001). The changes may be indirectly responsible legged frog metapopulations and Yosemite toad is sympatric with the for certain amphibian dieoffs by populations due to non-native fish mountain yellow-legged frog (their immune system suppression of larval or introductions. This is because there may ranges overlap). Therefore, it is possible postmetamorphic amphibians to the not be an adjacent mountain yellow- that this pathogen has affected both of extent that they are not resistant to legged frog population with habitat these amphibian species since at least diseases (Carey 1993; Blaustein et al. connectivity that is able to recolonize an the mid-1970s. Chytrid fungus is only a 1994b; Carey et al. 1999). Pathogens area following a pathogen-caused recently detected pathogen in such as red-leg disease, which are extinction event. amphibian populations; this may be an present in fresh water and in healthy D. The inadequacy of existing emerging infectious disease. How it has organisms, may erupt, potentially regulatory mechanisms. Existing been transmitted to the mountain causing localized amphibian population regulatory mechanisms that could yellow-legged frog is unclear (Briggs et dieoffs when the immune system of provide some protection for the al. 2002). individuals within the host population mountain yellow-legged frog in the Saprolegnia is a globally distributed are suppressed (Carey 1993; Carey and Sierra Nevada include: (1) Federal laws fungus that commonly attacks all life Bryant 1995). Wind-borne pesticides and regulations; (2) State laws and stages of fishes (especially hatchery from upwind agriculture potentially regulations; and (3) local land use reared fishes), and has recently been contribute to contaminant processes and ordinances. However, documented to attack and kill egg concentrations that may be high enough these regulatory mechanisms have not masses of western toads (Bufo boreas) to compromise amphibian immune prevented non-native fish introductions, (Blaustein et al. 1994b). This pathogen systems (Carey 1993; Carey et al. 1999; pathogen outbreaks, and habitat may be introduced through fish stocking Daszak et al. 1999). Recreationists may modifications, all of which result in or it may already be established in the contribute to the spread of pathogens population declines of mountain aquatic ecosystem. Fishes and/or between water bodies and populations yellow-legged frogs in the Sierra migrating or dispersing amphibians may via clothing and fishing equipment. Nevada. be a vector for this fungus (Blaustein et Given the uncertainty surrounding the Federal al. 1994b; Kiesecker et al. 2001). potential for researchers to contribute to Saprolegnia has not been reported in the the spread of pathogens, they have In response to the overgrazing by mountain yellow-legged frog; however, begun to implement equipment livestock of the available rangelands if hatchery fishes are vectors of this sterilization procedures between survey from the 1800s to the 1930s and the disease, it may have been introduced via sites (H. Eddinger, in litt. 2002; R. subsequent years of the Dust Bowl, fish stocking into historically occupied Knapp, in litt. 2002; V. Vredenburg, in Congress passed the Taylor Grazing Act mountain yellow-legged frog habitat. litt. 2002). in 1934. This was an effort to stop the No viruses were detected in the A compounding effect of disease- damage to the remaining public lands specimens of mountain yellow-legged caused extinctions of mountain yellow- from overgrazing and soil depletion, to frogs that Fellers et al. (2001) analyzed legged frogs is that recolonization may provide for an order to grazing on public for chytrid fungus. In Kings Canyon never occur, because streams connecting lands, and to attempt to stabilize the National Park, Knapp (pers. comm. extirpated sites to extant populations livestock industry using these lands 2002) found mountain yellow-legged now contain introduced fishes, which (Meehan and Platts 1978; Public Lands frogs showing symptoms preliminarily act as barriers to frog movement within Council et al. v. Babbitt Secretary of the attributed to a ranavirus. Mechanisms metapopulations. This isolates the Interior et al. (167 F. 3d 1287)). for disease transmission, including remaining populations of mountain Although passage of the Taylor Grazing viruses, to the mountain yellow-legged yellow-legged frogs from each other Act resulted in reduced grazing in some frog remain unknown. However, Mao et (Bradford 1991; Bradford et al. 1993). areas, it did not reduce grazing severity, al. (1999) isolated identical iridoviruses In summary, mountain yellow-legged as use remained high, and it did not from wild co-occurring populations of frogs are vulnerable to multiple allow regeneration of many meadow the threespine stickleback pathogens, whose effects range from areas (Beesley 1996; Menke et al. 1996; (Gasterostelus aculeatus) and the red- population persistence, with low levels Public Lands Council et al. v. Babbitt legged frog (Rana aurora), indicating of infection within populations, to Secretary of the Interior et al. (167 F. 3d that infection by a given virus is not extinction of entire populations. Little is 1287)). The Taylor Grazing Act of 1934, limited to a single species, and that understood about these pathogens, as amended, did initiate some grazing iridoviruses can infect animals making disease difficult to manage reform, possibly lessening impacts of belonging to different taxonomic without a better understanding of their livestock grazing on many species and classes. This suggests that if virus- life histories and modes of transmission. populations of wild plants and animals, hosting trout are introduced into Red-leg disease and chytrid fungus have including the mountain yellow-legged mountain yellow-legged frog habitat, been identified as having potentially frog and its habitat. However, it does not they may be a vector of amphibian catastrophic effects (localized have any provisions specific to the viruses. extinction) on mountain yellow-legged protection of either the mountain Whether amphibian pathogens in the frog populations. Though chytrid fungus yellow-legged frog or its habitat. high Sierra Nevada have always was only recently discovered to affect The Multiple-Use Sustained-Yield Act coexisted with amphibian populations amphibians (including the mountain of 1960 (MUSY), as amended, provided

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direction that the national forests be the mountain yellow-legged frog, and, if in contributing to a trend towards managed using principles of multiple the USFS has conducted such projects, Federal listing of species. Despite the use and to produce a sustained yield of what effects they have had. analyses pursuant to NEPA on all products and services. Specifically, The Wilderness Act of 1964 Federal actions potentially affecting the MUSY gives policy that the national established a National Wilderness mountain yellow-legged frog in the forests are established and shall be Preservation System made up of Sierra Nevada, and analyses pursuant to administered for outdoor recreation, federally owned areas designated by both NFMA and NEPA on national range, timber, watershed, wildlife, and Congress as ‘‘wilderness’’ for the forests, the species’ populations have fish purposes. Land management for purpose of preserving and protecting continued to decline (Bradford et al. multiple uses has inherent conflicts. designated areas in their natural 1993, 1994a; Drost and Fellers 1996; However, MUSY directs resource condition. Commercial enterprise, road Jennings 1996; Knapp 1996). management not to impair the construction, use of motorized vehicles The revised NMFA planning productivity of the land while giving or other equipment, and structural regulations recently proposed by the consideration to the relative values of developments are generally prohibited USFS (67 FR 72770) may affect the the various resources, though not within designated wilderness. Livestock status of this policy requirement (FSM necessarily in terms of the greatest grazing is permitted within designated 2620 and 2670), as the underlying financial return or unit output. This act wilderness, subject to other applicable regulatory framework pertaining to provides direction to the USFS that laws, if it was established prior to the providing for the diversity of plant and wildlife (which includes the mountain passage of this act. The Wilderness Act animal communities is proposed to be yellow-legged frog), is a value that must does not specifically mention fish substantially altered from the existing be managed for, though discretion is stocking although it does state that it regulatory requirement. The outcome of given to each national forest when shall not affect the jurisdiction or both the regulations and the related considering the value of the mountain responsibilities of States with wildlife policies that tier to them is uncertain. and fish responsibilities in the national yellow-legged frog relative to the other In the few cases where the Sierra forests. Whether fish stocking is uses for which they must manage. Nevada mountain yellow-legged frog permitted under the Wilderness Act is MUSY does not have any provisions occurs in habitat occupied by species an issue that has been debated (Bahls specific to the protection of either the listed pursuant to the Act, the mountain 1992; Landres et al. 2001). However, it mountain yellow-legged frog or its yellow-legged frog may be afforded habitat. generally has not limited fish stocking in the Sierra Nevada (Knapp 1996). protection under this legislation. The The Federal Land Policy and Passage of the Wilderness Act has not native Lahontan cutthroat trout Management Act of 1976 (FLPMA), as positively affected mountain yellow- (Oncorhynchus clarki henshawi) and amended, gives management direction legged frog populations in wilderness native Paiute cutthroat trout to the Bureau of Land Management; areas of the Sierra Nevada as it does not (Oncorhynchus clarki seleneris) are however, its application is to all Federal prevent fish stocking (Knapp and federally listed species, occurring lands, including those managed by the Matthews 2000). Potentially, the predominantly in drainages on the east USFS. FLPMA includes a provision Wilderness Act has helped to protect side of the Sierra Nevada. They co-occur requiring that 50 percent or $10,000,000 mountain yellow-legged frog habitat with several small populations of per year, whichever is greater, of all from development or other types of mountain yellow-legged frogs at lower moneys received through grazing fees habitat conversions and disturbances; elevations on the edge of the species’ collected on Federal lands (including however, mountain yellow-legged frog range. The native Little Kern golden the USFS-administered lands within the populations have continued to decline trout is a federally threatened species, range of the mountain yellow-legged despite its passage. co-occurring with the mountain yellow- frog) be spent for the purpose of on-the- The National Environmental Policy legged frog in a few isolated locations in ground range rehabilitation, protection, Act of 1969 (NEPA), as amended, the southern Sierra Nevada (Knapp and improvement. This includes all requires all Federal agencies to formally 1996; Moyle 2002). Recovery actions for forms of rangeland betterment such as document and publicly disclose the these trout species, such as physical fence construction, water development, environmental impacts of all actions habitat protection, may benefit the and fish and wildlife enhancement. Half and management decisions. NEPA mountain yellow-legged frog. For of the appropriated amount must be documentation is provided in either an example, on the Tahoe National Forest, spent within the national forest where environmental impact statement, an grazing, recreation, and other such moneys were derived. FLPMA environmental assessment, or a restrictions for the benefit of the provides for some rangeland categorical exclusion, and may be Lahontan cutthroat trout and its habitat improvements intended for the long- subject to administrative appeal or have been established. One of these term betterment of forage conditions litigation. The Pacific Southwest Region measures that benefits the mountain and resulting benefits to wildlife, (Region 5) of the USFS considers the yellow-legged frog is the establishment watershed protection, and livestock mountain yellow-legged frog a Forest of a bank protection measure that allows production. Land improvements Service sensitive species. Therefore, as for 10 percent bank disturbance initiated pursuant to FLPMA may have part of USFS policy, the analysis related (measured as bare ground accompanied benefitted the mountain yellow-legged to planning under the National Forest by soil displacement and/or cutting of frog and its habitat; however, some Management Act of 1976 (NFMA) and plant root crowns). Elsewhere the mountain yellow-legged frog habitat has conducted by the USFS to evaluate standard for bank disturbance is 20 continued to be destabilized and potential management decisions under percent (A. Carlson, in litt. 2002). deteriorate due to livestock grazing on NEPA includes a biological evaluation However, the use of chemicals or lands subject to FLPMA (R. Knapp, in which discloses potential impacts to electrofishing to remove non-native fish litt. 1993a, 1993b, 1994, 2002; Jennings sensitive species at both the forest from threatened trout habitat may 1995, 1996). We are unaware of any planning level and on a project-by- adversely affect mountain yellow-legged USFS-initiated projects developed project basis. Under USFS policy (FSM frogs present at the time of treatment. under FLPMA for the specific benefit of 2620 and 2670), projects must not result Additionally, listed native trout species

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may prey on the mountain yellow- to provide for the viability of its been degraded by a history of livestock legged frog at sites where they co-occur. associated native species via an aquatic use. The Forest and Rangeland Renewable management strategy. The aquatic To help meet these goals, the aquatic Resources Planning Act of 1974, as management strategy is a general management strategy proposes a broad amended by NFMA, specifies that all framework with broad policy direction. initial action to address the mountain national forests must have a land and Implementation of this strategy is yellow-legged frog in a conservation resource management plan (LRMP). The intended to take place at the landscape plan developed by the USFS with other purpose of the LRMP is to guide and set and project levels. There are nine goals State and Federal agencies; an effort by standards for all natural resource associated with the aquatic management the USFS to do this is underway. Where management activities for the life of the strategy. They include: (1) The known locations of mountain yellow- plan (10 to 15 years) on each national maintenance and restoration of water legged frogs occur on the national forest. NFMA requires the USFS to quality to comply with the Clean Water forests, critical aquatic refuges will be incorporate standards and guidelines Act (CWA) and the Safe Drinking Water designated. A primary management goal into LRMPs. This has historically been Act; (2) the maintenance and restoration for the critical aquatic refuges is to done through a NEPA process, of habitat to support viable populations contribute to the viability and recovery including provisions to manage plant of native and desired non-native of sensitive species (including the and animal communities for diversity, riparian-dependent species and to mountain yellow-legged frog) through based on the suitability and capability reduce negative impacts of non-native habitat preservation, enhancement, of the specific land area in order to meet species on native populations; (3) the restoration, or connectivity. Within the aquatic management strategy, critical overall multiple-use objectives. The maintenance and restoration of species 1982 planning regulations for aquatic refuges are given highest diversity in riparian areas, wetlands, implementing NFMA, under which all priority for evaluating how existing and and meadows to provide desired existing forest plans were prepared and proposed activities are consistent with habitats and ecological functions; (4) the which still guide management, also the goals of the strategy. The aquatic maintenance and restoration of the required that fish and wildlife habitat management strategy directs existing distribution and function of biotic on national forest system lands ‘‘*** and proposed activities within critical communities and biological diversity in shall be managed to maintain viable aquatic refuges to be consistent with the special aquatic habitats (such as springs, populations of existing native and goals of the critical aquatic refuges. This seeps, vernal pools, fens, bogs, and desired non-native vertebrate species in evaluation will be made using the the planning area. For planning marshes); (5) the maintenance and riparian conservation objectives and purposes, a viable population is one restoration of spatial and temporal associated standards and guidelines, as which has the estimated numbers and connectivity for aquatic and riparian defined in the ROD for the SNFPA. One distribution of reproductive individuals species within and between watersheds such standard and guideline specific to to insure its continued existence is well to provide physically, chemically, and the mountain yellow-legged frog distributed in the planning area. In biologically unobstructed movement for includes the avoidance of pesticide order to insure that viable population their survival, migration, and applications from within 152 m (500 ft) will be maintained, habitat must be reproduction; (6) the maintenance and of sites known to be occupied by the provided to support, at least, a restoration of hydrologic connectivity species. minimum number of reproductive between floodplains, channels, and Management standards and guidelines individuals and that habitat must be water tables to distribute flood flows in the SNFPA ROD for the Yosemite well distributed so that those and to sustain diverse habitats; (7) the toad will also benefit the mountain individuals can interact with others in maintenance and restoration of yellow-legged frog in areas where these the planning area.’’ watershed conditions as measured by two species overlap. These standards In 2001, a record of decision (ROD) favorable infiltration characteristics of and guidelines exclude livestock from was signed by the USFS for the Sierra soils and diverse vegetation cover to standing water and saturated soils in Nevada Forest Plan Amendment absorb and filter precipitation, and to wet meadows and associated streams (SNFPA), based on the final sustain favorable conditions of stream and springs occupied by Yosemite environmental impact statement (FEIS) flows; (8) the maintenance and toads, or identified as essential habitat for the SNFPA effort and prepared restoration of instream flows sufficient for this species in the USFS’s under the 1982 NFMA planning to sustain desired conditions of riparian, conservation assessment for this regulations. The ROD amends the USFS aquatic, wetland, and meadow habitats species. Pacific Southwest Regional Guide, the and to keep sediment regimes within The SNFPA includes requirements for Intermountain Regional Guide, and the the natural range of variability; and (9) monitoring to determine how well the LRMPs for national forests in the Sierra the maintenance and restoration of the aquatic management strategy goals and Nevada and Modoc Plateau. This physical structure and condition of the riparian conservation objectives document affects land management on stream banks and shorelines to have been met, and how closely all national forests throughout the range minimize erosion and sustain desired management standards and guidelines of the mountain yellow-legged frog. The habitat diversity. If these goals are have been applied. SNFPA addresses and gives pursued and met, the mountain yellow- Our review of the SNFPA FEIS and management direction on issues legged frog and its habitat could benefit. ROD indicate that full implementation pertaining to old forest ecosystems; These goals, though broadly stated, of the SNFPA would benefit the aquatic, riparian, and meadow include measures to reduce impacts of mountain yellow-legged frog and its ecosystems; fire and fuels; noxious non-native trout predation on mountain habitat. National forests affected by the weeds; and lower westside hardwood yellow-legged frogs as well as the SNFPA are responsible for ecosystems of the Sierra Nevada. resulting isolation of populations. These implementing it; however, Relevant to the mountain yellow- goals, if met, would also restore implementation is subject to funding. legged frog, the ROD for the SNFPA mountain yellow-legged frog aquatic Also, current direction from within the aims to protect and restore aquatic, habitats, including meadows, fens, USFS is to internally review the entire riparian, and meadow ecosystems, and stream banks, and shorelines that have record (including the FEIS, the existing

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ROD, public and agency comments, and the United States, including wetlands. The California Environmental Quality the appeals and responsive statements), Projects that are subject to regulation Act (CEQA) pertains to projects on non- to evaluate primarily the effects of its may qualify for authorization to place Federal lands and requires review of implementation on grazing, recreation, fill material into headwaters and any project that is undertaken, funded, and impacts to local communities (J. isolated waters, including wetlands, or permitted by a State or local Blackwell, USFS, in litt. 2001). This under several nationwide permits. The governmental agency. If a project with review and assessment may result in use of nationwide permits by an potential impacts on the mountain proposed changes to the SNFPA and its applicant or project proponent is yellow-legged frog in the Sierra Nevada associated documents. Therefore, the normally authorized with minimal is reviewed, CDFG personnel could extent to which it will continue to be environmental review by the Corps. An determine that, although not state-listed, implemented, and the extent to which it individual permit may be required by the frog is de facto an endangered, may benefit the mountain yellow-legged the Corps if a project otherwise threatened, or rare species under section frog and its habitat, remain qualifying under a nationwide permit 15380 of CEQA. Once significant effects undetermined. There is additional would have greater than minimal are identified, the lead agency has the uncertainty because the proposed adverse environmental impacts. option of requiring mitigation for effects changes to the NFMA planning However, few projects that include fill through changes in the project or to regulations recently issued by Forest of wetlands are likely to occur within decide that overriding considerations Service (67 FR 72770) contain two the range of the mountain yellow-legged make mitigation infeasible (CEQA Sec. options for meeting the NFMA direction frog. 21002). In the latter case, projects may to provide for the diversity of plant and be approved that cause significant State animal communities, and both options environmental damage, such as would change the current regulation The State of California considers the destruction of state-listed endangered pertaining to forest planning to provide mountain yellow-legged frog a species species or their habitat. Protection of habitat to support viable populations. of special concern, but it is not State listed species through CEQA is, The statute establishing the National listed as a threatened or endangered therefore, dependent on the discretion Park Service, commonly referred to as species and thus is not protected under of the agency involved. In addition, fish the National Park Service Organic Act the California Endangered Species Act. stocking is not subject to disclosure of (39 Stat. 535; 16 U.S.C. 1,2,3 and 4) California Sport Fishing Regulations its potential environmental impacts states that the NPS will administer areas include the mountain yellow-legged frog because it is exempt from CEQA under under their jurisdiction ‘‘. . .by such as a protected species that may not be Article 19 section 15301(j). Therefore, means and measures as conform to the taken or possessed at any time with a the effects of fish stocking on the fundamental purpose of said parks, sport fishing license. Possession or take mountain yellow-legged frog are not monuments, and reservations, which of the mountain yellow-legged frog is analyzed pursuant to CEQA. Also, the purpose is to conserve the scenery and authorized under special permit from vast majority of the species’ range is on the natural and historic objects and the the CDFG. This gives the frog some legal Federal land and is affected by Federal wildlife therein and to provide for the protection from collecting, but does not actions (other than the State-sponsored enjoyment of the same in such manner protect it from other causes of mortality fish stocking) that are not subject to and by such means as will leave them or alterations to its habitat. CEQA analysis. unimpaired for the enjoyment of future The California Forest Practice rules Section 1603(a) of the California Fish generations.’’ The 2001 edition of NPS set guidelines for the design of timber and Game Code requires a permit from Management Policies (NPS D1416) harvests on private land to reduce the CDFG for any activity that may alter further elaborates on how impacts on impacts on non-listed species. These the bed, channel, or bank of any river, park resources, including native rules have little application to the stream, or lake. The permit may organisms, will not be allowed to the protection of the mountain yellow- incorporate measures to minimize level that they would constitute legged frog because the vast majority of adverse impacts to fish and wildlife. impairment: ‘‘To comply with this the species’ range is on Federal land, Therefore, this regulation may offer mandate, park managers must determine and much of its range is too high in some protection of mountain yellow- in writing whether proposed activities elevation to overlap with lands used for legged frog habitat. The extent to which in parks would impair natural commercial timber harvest. this regulation has provided the resources. Park managers must also take The California Department of mountain yellow-legged frog with action to ensure that ongoing NPS Pesticide Regulation (CDPR) has protection is unknown because much of activities do not cause impairment. In authority to restrict the use of the range of this species is on federal cases of doubt as to the impact of pesticides. The CDPR Toxic Air lands where few habitat modifications activities on park natural resource, the Contaminant (TAC) Program includes subject to this permit are proposed. Service will decide in favor of assessment of the risks posed by The CDFG is practicing an informal protecting the natural resources.’’ airborne pesticides; this assessment policy on fish stocking in the range of Sequoia, Kings Canyon, and Yosemite involves collection of air samples near the mountain yellow-legged frog in the National Parks began phasing out fish sites of pesticide application and in Sierra Nevada. This policy directs that: stocking in 1969 and terminated this communities near those sites. If air (1) Fish will not be stocked in lakes practice entirely in 1991 (Bahls 1992; samples indicate that reductions in with known populations of mountain Knapp 1996). exposure are needed, mitigation yellow-legged frogs, nor in lakes which Under section 404 of the Clean Water measures are developed to bring about have not yet been surveyed for Act, the U.S. Army Corps of Engineers those reductions (CDPR 2001). However, mountain yellow-legged frog presence; (Corps) regulates the discharge of fill the TAC program is intended primarily (2) waters will be stocked only with a material into waters of the United to protect human health, and air fisheries management justification; and States, including wetlands. Section 404 samples are not taken at far distant (3) the number of stocked lakes will be regulations require applicants to obtain locations from application sites, like reduced over time. In 2001, the number a permit for projects that involve the those inhabited by the mountain yellow- of lakes stocked with fish within the discharge of fill material into waters of legged frog in the Sierra Nevada. range of the mountain yellow-legged

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frog in the Sierra Nevada was reduced protection for the Sierra Nevada been detected in precipitation (rain and by 75 percent (C. Milliron, in litt. 2002; population of mountain yellow-legged snow), air, dry deposition, surface E. Pert, CDFG, pers. comm. 2002; E. Pert frogs. water, plants, fish, and amphibians, et al., pers. comm. 2002). Water bodies E. Other natural or manmade factors including Pacific tree frogs and within the same basin and 2 km (1.25 affecting its continued existence. mountain yellow-legged frogs (Cory et mi) from a known mountain yellow- Several other natural or al. 1970; Zabik and Seiber 1993; Aston legged frog population will not be anthropogenically influenced factors, and Seiber 1997; Datta et al. 1998; stocked with fish unless stocking is including contaminants, acid McConnell et al. 1998; LeNoir et justified through a management plan precipitation, climate change and al.1999; Sparling et al. 2001; that considers all the aquatic resources drought, and ambient ultraviolet Angermann et al. 2002). Angermann et in the basin, or unless there is heavy radiation, have been implicated as a al. (2002) detected elevated contaminant angler use and no opportunity to cause of amphibian declines (Corn 1994; (polychlorinated biphenyls and improve the mountain yellow-legged Alford and Richards 1999). These toxaphene) levels in Pacific tree frog frog habitat (C. Milliron, in litt. 2002). factors have been studied to varying larvae within the range of the mountain This policy has not been finalized in degrees specific to the mountain yellow- yellow-legged frog, and suggested that writing (E. Pert et al., pers. comm. legged frog. These factors are discussed these contaminants originate in 2002). below. California’s Central Valley and The CDFG is in the process of The following factors make the metropolitan areas. Spatial analysis of developing management plans for mountain yellow-legged frog, along with populations of the California red-legged basins within the range of the mountain other amphibians, sensitive to frog (Rana aurora draytonii), foothill yellow-legged frog in the Sierra Nevada environmental change or degradation: yellow-legged frog, Cascades frog (R. (CDFG 2001; C. Milliron, in litt. 2002; E. its aquatic and terrestrial phases; its cascadae), and the mountain yellow- Pert, pers. comm. 2002; E. Pert et al., highly permeable skin which is exposed legged frog in the Sierra Nevada showed pers. comm. 2002). For example, a plan to substances in the water, air, and a strong, statistically significant pattern has been developed, signed, and terrestrial substrate; and the position at of population decline associated with initiated for the Big Pine Creek which it feeds on the food web, greater amounts of upwind agriculture wilderness basin in the Inyo National depending on its life stage (Blaustein (Davidson et al. 2002). Forest’s John Muir Wilderness (CDFG and Wake 1990, 1995; Bradford and Cholinesterase is an enzyme that 2001), and a similar plan is proposed for Gordon 1992; Stebbins and Cohen functions in the nervous system and is the Gable Lakes basin, also in the John 1995). Environmental contaminants disrupted by organophosphorus Muir Wilderness area of the Inyo have been suggested, and in some cases pesticides, including malathion, National Forest (B. Miller, CDFG, in litt. documented, to negatively affect chlorpyrifos, and diazinon (Sparling et 2001). The objectives of the Big Pine amphibians by causing the following: al. 2001). Reduced cholinesterase Creek wilderness basin plan specific to direct mortality (Hall and Henry 1992; activity and pesticide residues have the mountain yellow-legged frog include Berrill et al. 1994, 1995; Carey and been found in Pacific treefrog larvae management in a manner that maintains Bryant 1995; Relyea and Mills 2001); collected in the Sierra Nevada or restores native biodiversity and immune system suppression, which downwind of the Central Valley habitat quality, supports viable makes amphibians more vulnerable to (Sparling et al. 2001). Cholinesterase populations of native species, and disease (Carey 1993; Carey and Bryant activity was significantly lower in provides for recreational opportunities 1995; Carey et al. 1999; Daszak et al. samples from the Sierra Nevada than in that consider historic use patterns 1999; Taylor et al. 1999); disruption of samples taken from coastal California, (CDFG 2001). Under this plan, some breeding behavior and physiology upwind of the Central Valley. No lakes are managed primarily for the (Berrill et al. 1994; Carey and Bryant samples were taken above mountain yellow-legged frog, with few 1995, Hayes et al. 2002); disruption of approximately 1,500 m (4,900 ft) or no angling opportunities, while lakes growth or development (Hall and Henry elevation (Sparling et al. 2001), so in with high demand for recreational 1992; Berrill et al. 1993, 1994, 1995, this study there is limited overlap with angling are managed primarily for that 1998; Carey and Bryant 1995; Sparling the 1,370 to 3,650 m (4,500 to 12,000 ft) purpose (CDFG 2001). Preliminary et al. 2001); and disruption of the ability elevational range (Stebbins 1985) of results indicate that where the plans are to avoid predation (Hall and Henry mountain yellow-legged frogs. Although being implemented, the management 1992; Berrill et al. 1993, 1994, 1995, pesticide detections decrease with objective to restore mountain yellow- 1998; Carey and Bryant 1995; Relyea altitudinal gain, they have been detected legged frog habitat is being achieved, and Mills 2001; Sparling et al. 2001). at elevations in excess of 3,200 m and in some areas, mountain yellow- Wind-borne pesticides and the (10,500 ft) (Zabik and Seiber 1993; legged frog populations have responded compounds that carry pesticides from Aston and Seiber 1997; McConnell et al. positively (C. Milliron, pers. comm. upwind agriculture that are deposited in 1998; LeNoir et al. 1999; Angermann et 2002). We anticipate that the the Sierra Nevada have been suggested al. 2002). In addition to interfering with development and implementation of as a cause of measured sublethal effects nerve function, contaminants such as these basin management plans will be to amphibians (Cory et al. 1971; industrial and agricultural chemicals effective in reversing some of the Davidson et al. 2001; Sparling et al. may act as estrogen mimics (Jobling et negative impacts of introduced trout on 2001). In 1998, more than 97 million al. 1996), causing abnormalities in mountain yellow-legged frog kilograms (215 million pounds) of amphibian reproduction and disrupting populations within a limited geographic pesticides reported to be used in endocrine functions (Carey and Bryant area of the affected basins, providing California (CDPR 1998). Originating 1995; Stebbins and Cohen 1995; Jobling that connectivity is restored between from the agriculture in California’s et al. 1996; Hayes et al. 2002), thereby and within metapopulations. Central Valley, and mainly from the San having a negative effect on amphibian Joaquin Valley where agricultural populations, including the mountain Local activity is greatest, pesticides are yellow-legged frog. We are not aware of any specific passively transported eastward to the In the late 1960s, county or city ordinances that provide high Sierra Nevada where they have dichlorodiphenyltrichloroethane (DDT)

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and its residues were detected in Joaquin Valley are suppressing the Sierra Nevada (approximately 10) are significant quantities in mountain mountain yellow-legged frog’s immune naturally acidic (Bradford et al. 1998). yellow-legged frogs and foothill yellow- system, thereby making it more Bradford et al. (1998) found mountain legged frogs throughout the Sierra vulnerable to disease, is underway yellow-legged frog tadpoles to be Nevada up to an elevation of 3,660 m (Briggs et al. 2002). sensitive to naturally acidic conditions, (12,000 ft) (Cory et al. 1970). The origin Laboratory studies have documented and that their distribution was of this DDT is primarily attributed to sublethal effects on mountain yellow- significantly related to lake acidity; they agriculture in the Central Valley (Cory et legged frog embryos at pH 5.25 (pH were not found in lakes with a pH less al. 1970). DDT residues likely from represents acidity on a negative scale, than 6. By contrast, the distribution of agriculture in the Central Valley still with 7 being neutral and lower numbers adult mountain yellow-legged frogs was appeared in Pacific treefrog larvae indicating increased acidity). not significantly related to natural lake collected in the Sierra Nevada in the Survivorship of mountain yellow-legged acidity or other chemical or physical late 1990s (Sparling et al. 2001), more frog embryos and tadpoles was parameters. Though acidity may have an than 25 years after the use of DDT was negatively affected as acidity increased influence on mountain yellow-legged banned in the United States. Levels of (at approximately pH 4.5 or lower), with frog abundance or distribution, it is this toxicant in the mountain yellow- embryos being more sensitive to unlikely to have contributed to this legged frog and foothill yellow-legged increased acidity than tadpoles species’ decline, given the rarity of lakes frog were significantly higher in the (Bradford and Gordon 1992; Bradford et acidified either by natural or central Sierra Nevada, from the al. 1992). Acidic deposition has been anthropogenic sources (Bradford et al. Tuolumne Meadows area of Yosemite suggested as contributing to amphibian 1998). National Park, north to Sonora Pass in declines in the western United States The last century has included some of the Stanislaus National Forest. The (Blaustein and Wake 1990; Carey 1993; the most variable climate reversals origin of DDT at these locations is Alford and Richards 1999). Other documented, at both the annual attributed to two massive applications studies, however, do not support this (extremes and high frequency of El Ni– administered directly to this national hypothesis as a contributing factor to o (associated with severe winters) and forest and national park for pest control amphibian population declines in this La Ni–a (associated with milder winters) (Cory et al. 1970, 1971). area (Bradford and Gordon 1992; events) and near-decadal scales (periods Snow core samples from the Sierra Bradford et al. 1992; Corn and Vertucci of 5 to 8 year drought and wet periods) Nevada contain a variety of 1992; Bradford et al. 1994a, 1994b). (USDA 2001b). These events may have contaminants from industrial and Acid precipitation has been negative effects on Sierra Nevada automotive sources, including hydrogen postulated as a cause of amphibian mountain yellow-legged frogs. Severe ions that are indicative of acidic declines at high elevations in the Sierra winters (El Ni–o) would force longer precipitation, nitrogen and sulfur Nevada because waters there are low in hibernation times and could stress compounds (NH4, NO3, SO2, and SO4), acid neutralizing capacity, and, mountain yellow-legged frogs by and heavy metals (lead, iron, therefore, are susceptible to changes in reducing the time available for them to manganese, copper, and cadmium) water chemistry caused by acidic feed and breed. Alternately, during mild (Laird et al. 1986). The pattern of recent deposition (Byron et al. 1991; Bradford winters (La Ni–a), precipitation is frog extinctions in the southern Sierra et al. 1994b). Near Lake Tahoe, at an reduced. This reduction in precipitation Nevada corresponds with the pattern of elevation of approximately 2,100 m could reduce available breeding habitat highest concentration of air pollutants (6,900 ft), precipitation acidity has been and lead to stranding and death of frog from automotive exhaust, possibly due documented to have increased eggs and tadpoles. It could also lead to to increases in nitrification (or other significantly (Byron et al. 1991). In increased exposure to predatory fish by changes), caused by those pollutants surface waters of the Sierra Nevada, forcing frogs into fish-containing waters (Jennings 1996). The effects of acidity increases and acid neutralizing if fishless waters dry out. contaminants on amphibians need capacities decrease during snow melt In California, prolonged droughts are further research (Hall and Henry 1992; and summer storms, though rarely does a regular occurrence to which native Briggs et al. 2002). However, the pH dip below 5.6 (Nikolaidis et al. 1991; amphibians have adapted; even severe correlative evidence between areas of Bradford and Gordon 1992; Bradford et droughts are not expected to result in pesticide contamination in the Sierra al. 1998). The mountain yellow-legged widespread population declines (Drost Nevada and areas of amphibian decline, frog breeds shortly after snow melt, and Fellers 1996). However, an increase along with evidence of an adverse thereby exposing its early life stages, in the frequency, magnitude, and physiological effect from pesticides on which are most sensitive to duration of droughts caused by global amphibians in the Sierra Nevada, acidification, to these conditions warming may have compounding effects indicates that contaminants may present (Bradford and Gordon 1992). However, with respect to populations of mountain a risk to the mountain yellow-legged the hypothesis of acidic deposition as a yellow-legged frogs already in decline. frog and may have contributed to the cause of mountain yellow-legged frog In situations where other factors have species’ decline (Jennings 1996; declines has been rejected by field resulted in the isolation of mountain Sparling et al. 2001; (Davidson et al., experiments that failed to show yellow-legged frogs to marginal habitats, 2002). differences in water chemistry localized mountain yellow-legged frog It has been suggested that parameters between occupied and population crashes or extirpations due contamination from wind-borne unoccupied mountain yellow-legged to droughts may exacerbate their pesticides originating from upwind frog sites (Bradford et al. 1994b). isolation and preclude their agriculture, and other contaminants Extreme pH in surface waters of the recolonization or immigration from originating from metropolitan areas, Sierra Nevada is estimated at 5.0, with other populations (Bradford et al. 1993; may compromise amphibian immune most high elevation lakes having a pH Drost and Fellers 1996). systems (Carey 1993; Carey et al. 1999; of greater than 6 (Bradford et al. 1992, Changes in climate that occur faster Daszak et al. 1999; Angermann et al. 1998). Caused by oxidation of pyrite than the ability of endangered species to 2002). An effort to test the hypothesis found in metamorphic and granitic adapt could cause local extinctions that contaminants originating in the San rocks, a small number of lakes in the (U.S. Environmental Protection Agency

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(EPA) 1989). Analysis of the Antarctic 2001; Davidson et al., 2002). Melanic introduction and subsequent predation Vostok ice core has shown that over the pigment on the upper surfaces of of non-native fishes, as documented in past 160,000 years, temperatures have amphibian eggs and larvae protects the body of scientific research on the varied with fluctuations in the these sensitive life stages against UV–B distributions of introduced trout in concentrations of greenhouse gasses damage, an important protection for relation to mountain yellow-legged frogs such as carbon dioxide and methane. normal development of amphibians (Bradford 1989; Bradford et al. 1993, Since the pre-industrial era, exposed to sunlight, especially at high 1994a, 1998; Knapp 1994, 1996; Drost atmospheric concentrations of carbon elevations in clear and shallow waters and Fellers 1996; Knapp and Matthews dioxide have increased nearly 30 (Stebbins and Cohen 1995). Blaustein et 2000; Knapp et al. 2001). Direct percent, methane concentrations have al. (1994c) observed decreased hatching predation of non-native fishes on more than doubled, and nitrous oxide success in several species of amphibian mountain yellow-legged frogs has (another greenhouse gas) levels have embryos (the mountain yellow-legged resulted in range-wide population risen approximately 15 percent. The frog was not tested) exposed to declines and local extirpations. burning of fossil fuels is the primary increased UV–B radiation, indicating Furthermore, the result of these source of these increases. Global mean that this may be a cause of amphibian extirpations is that the remaining surface temperatures have increased declines. Juveniles and adults may be populations are fragmented and 0.3–0.7 °C (0.6–1.2 °F)) since the late exposed to increased UV–B levels as isolated, making them vulnerable to 19th century (EPA 1997). Climate they heat themselves by basking in the further declines and local extirpations modeling indicates that the overall sun (Stebbins and Cohen 1995). In a from other factors. Populations that go effects of global warming on California spatial test of the hypothesis that extinct following habitat fragmentation will include higher average UV–B has contributed to decline of the and populations isolation are unlikely temperatures in all seasons, higher total mountain yellow-legged frog in the to be recolonized due to both the annual precipitation, and decreased Sierra Nevada, Davidson et al. (2002) isolation from, and lack of, habitat spring and summer runoff due to concluded that patterns of this species connectivity to potential source decreases in snowpacks (EPA 1989, decline are inconsistent with the populations. 1997). Decreases in spring and summer predictions of where UV–B related For example, in reviewing runoff could lead to the loss of breeding population declines would occur. documented mountain yellow-legged habitat for mountain yellow-legged frogs Greater numbers of extant populations frog declines over the last 5 years in and increases in instances of stranding of this species were present at higher Sequoia and Kings National Parks, we mortality of eggs and tadpoles. elevations than at lower elevations, and found a 39 percent extinction rate of the Changes in temperature may also population decline was greater in the frog where fish have not been stocked affect virulence of pathogens to a northern portion of the range of this since the late 1970s. In comparison, different degree than the amphibian species than it was in the southern over the last 7 years in the Sierra immune systems are able to respond portion. Though it does not appear that National Forest’s John Muir Wilderness (Carey et al. 1999) and may make UV–B is a factor in the decline of the Area, there has been a 61 percent mountain yellow-legged frogs more mountain yellow-legged frog, the extinction rate where fish stocking has susceptible to disease. Global warming absence of the predicted pattern for UV– continued. This high rate of extinction could also affect the distribution of B-caused decline should not be taken as over a 5 to 7 year time frame suggests pathogens and their vectors, exposing proof that UV–B is not affecting the the species’ extinction within a few mountain yellow-legged frogs mountain yellow-legged frogs, given the decades (assuming that the rate of (potentially with weakened immune potential for one or more factors that extinction and recolonization observed systems as a result of other cause population declines to mask other over this time period accurately reflects environmental stressors) to new factors (Davidson et al., 2002). the long-term rates) (R. Knapp, in litt. pathogens (Blaustein et al. 2001). An 2002.). experimental increase in stream water Finding The isolation of remaining mountain temperature was shown to decrease We have carefully assessed the best yellow-legged frog populations and density and biomass in invertebrates scientific and commercial information habitat fragmentation as a result of non- (Hogg and Williams 1996); thus, global available regarding the past, present, native fish introductions has made warming might have a negative impact and future threats faced by this species. remaining populations vulnerable to on the mountain yellow-legged frog prey We reviewed the petition, information extinction from random events such as base. available in our files, other published disease. Disease has only recently been Ambient ultraviolet-b (UV–B) and unpublished information submitted recognized as an important factor in the radiation (280–320 nanometers (11.0– to us during the public comment period decline of this species. It appears, 12.6 microinches)) has increased at following our 90-day petition finding, however, that disease will continue to north temperate latitudes in the past and consulted with recognized play an important role in the decline of two decades (Adams et al. 2001). If UV– mountain yellow-legged frog experts this species. It is likely that disease, B radiation is contributing to amphibian and other Federal and State resource specifically chytrid fungus, has population declines, the declines would agencies. On the basis of the best contributed to the recently observed likely be greater at higher elevations and scientific and commercial information declines in Sequoia and Kings Canyon at more southerly latitudes where UV– available, we find that listing the Sierra National Parks and in the Sierra B exposure is greatest, where the Nevada DPS of the mountain yellow- National Forests’s John Muir Wilderness thinner atmosphere allows greater legged frog is warranted, but is Area (R. Knapp, in litt. 2002). Although penetration of UV–B (Davidson et al. precluded by higher priority listing the life history and modes of 2001; Davidson et al., 2002). In actions. transmission of chytrid fungus are not California, where there is a north-to- In making this finding, we recognize well understood, it appears that this south gradient of increasing UV–B that there have been declines in the pathogen is widespread throughout the exposure, amphibian declines would distribution and abundance of the Sierra range of the mountain yellow-legged also likely be more prevalent at Nevada DPS of the mountain yellow- frog within the Sierra Nevada, it is southerly latitudes (Davidson et al. legged frog, primarily attributed to the persistent in ecosystems, and it is

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resilient to environmental conditions month finding. We will continue to at-sea (DAS) adjustment, and such as drought and freezing. Therefore, monitor the status of this species and continuation of a Sea Scallop Area we conclude that all remaining yellow- other candidate species. Should an Access Program (Area Access Program) legged frog populations within the emergency situation develop with one for 2003. The intent of this action is to Sierra Nevada are at risk to declines and or more of the species, we will act to achieve the goals and objectives of the extirpation as a result of infection by provide immediate protection, if FMP under the Magnuson-Stevens this pathogen. warranted. Fishery Conservation and Management Other factors include airborne We intend that any proposed listing Act and to achieve optimum yield in the contaminants, habitat degradation action for the Sierra Nevada DPS of the scallop fishery. In addition, this (mainly as a result of livestock grazing) mountain yellow-legged frog will be as proposed rule includes regulatory text and the inadequacy of existing accurate as possible. Therefore, we will that would codify an additional gear regulatory mechanisms. Each of these continue to accept additional stowage provision for scallop dredge factors may contribute to mountain information and comments from all gear that was established by the yellow-legged frog population declines concerned governmental agencies, the Administrator, Northeast Region, NMFS or extirpations. In addition, these factors scientific community, industry, or any (Regional Administrator) in 2001. are exacerbated by the effects that have other interested party concerning this DATES: Comments must be received on been caused by non-native fishes, finding. or before 5 p.m., local time, on January specifically the isolation of remaining 31, 2003. References Cited mountain yellow-legged frog ADDRESSES: Written comments should populations and habitat fragmentation. A complete list of all references cited be sent to Patricia A. Kurkul, Regional As noted previously, populations that is available on request from the Administrator, NMFS, Northeast go extinct following habitat Sacramento Fish and Wildlife Office Regional Office, One Blackburn Drive, fragmentation and population isolation (see ADDRESSES section, above). Gloucester, MA 01930. Mark the outside are unlikely to be recolonzied due to Author of the envelope, ‘‘Comments on both the isolation from, and lack of, Framework 15 to the Scallop FMP.’’ connectivity to potential source The primary author of this document Comments also may be sent via populations. is Peter Epanchin of the Sacramento facsimile (fax) to (978) 281–9135. We conclude that the overall Fish and Wildlife Office (see FOR Comments will not be accepted if magnitude of threats to the Sierra FURTHER INFORMATION CONTACT section). submitted via e-mail or Internet. Nevada DPS of the mountain yellow- Authority: The authority for this action is Copies of Framework Adjustment 15, legged frog is high, and that the overall the Endangered Species Act of 1973, as its Regulatory Impact Review (RIR) immediacy of these threats is imminent. amended (16 U.S.C. 1531 et seq.). including the Initial Regulatory Pursuant to our Listing Priority System Flexibility Analysis (IRFA), and the (64 FR 7114), a DPS of a species for Dated: January 10, 2003. Marshall P. Jones, Jr., Environmental Assessment (EA) are which threats are high and imminent is available on request from Paul J. Director, Fish and Wildlife Service. assigned a Listing Priority Number of 3. Howard, Executive Director, New While we conclude that listing the [FR Doc. 03–973 Filed 1–15–03; 8:45 am] England Fishery Management Council, Sierra Nevada DPS of the mountain BILLING CODE 4310–55–P 50 Water Street, Newburyport, MA yellow-legged frog is warranted, an 01950. These documents are also immediate proposal to list is precluded available online at http:// DEPARTMENT OF COMMERCE by other higher priority listing actions. www.nefmc.org. During Fiscal Year 2003 we must spend nearly all of our Listing Program National Oceanic and Atmospheric FOR FURTHER INFORMATION CONTACT: funding to comply with court orders Administration Peter W. Christopher, Fishery Policy and judicially approved settlement Analyst, 978–281–9288; fax 978–281– agreements, which are now our highest 50 CFR Part 648 9135; e-mail [email protected]. priority actions. To the extent that we [Docket No. 030108004-3004-01; ID have discretionary funds, we will give 010303B] SUPPLEMENTARY INFORMATION: On priority to using them to address September 12, 2002, the Council RIN 0648–AQ28 emergency listings and listing actions adopted Framework 15 to the FMP, for other species with a higher priority. Fisheries of the Northeastern United which proposes annual management Due to litigation pertaining to various States; Atlantic Sea Scallop Fishery; measures for the 2003 fishing year listing actions, our planned work with Framework Adjustment 15 (March 1, 2003, through February 29, listing funds in Fiscal Year 2003 2004). Framework 15 would increase consists primarily of addressing court- AGENCY: National Marine Fisheries the annual DAS allocation, and extend ordered actions, court-approved Service (NMFS), National Oceanic and the Area Access Program in the Hudson settlement agreements, and listing Atmospheric Administration (NOAA), Canyon and Virginia Beach areas for actions that are in litigation. (Also, some Commerce. 2003. The only modification to the litigation-related listing actions already ACTION: Proposed rule; request for measures that have been in effect for the are scheduled for Fiscal Year 2004.) We comments. 2002 fishing year would be an increase expect that our discretionary listing in the possession limit allowed to activity in Fiscal Year 2003 will focus SUMMARY: NMFS proposes regulations to vessels participating in the Area Access on addressing our highest priority implement Framework 15 to the Program. This increase is intended to be listing actions of finalizing expiring Atlantic Sea Scallop Fishery consistent with increasing catch rates in emergency listings. Management Plan (FMP) developed by the area so that there is sufficient The Sierra Nevada DPS of the the New England Fishery Management incentive for vessels to fish in these mountain yellow-legged frog will be Council (Council). This rule proposes to areas. added to the list of candidate species implement management measures for Regulations implementing upon publication of this notice of 12- the 2003 fishing year, including a days- Amendment 7 to the FMP (64 FR 14835,

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