Rocky Mountain Tailed Frog - Ascaphus montanus
(see State Rank Reason below)
State Rank Reason (see State Rank above)
Species is apparently secure and not at risk of extirpation or facing significant threats in all or most of its range.
- Details on Status Ranking and Review
ScoreF - 20,000-200,000 km squared (about 8,000-80,000 square miles)
Comment70,521 square Kilometers from Natural Heritage Program range maps
ScoreE - Relatively Stable (±25% change)
CommentAlthough forest management practices and fire regimes have changed over the last century it is unlikely that the amount of habitat for this species has changed more than 25%. Loss of old growth timber may have contributed to a reduction in suitable habitat, but the extent of the impact on this species is unknown.
ScoreU - Unknown. Short-term trend in population, range, area occupied, and number and condition of occurrences unknown.
CommentTo date surveys have not been conducted with enough frequency to determine trend
ScoreG - Slightly threatened. Threats, while recognizable, are of low severity, or affecting only a small portion of the population or area.
CommentDegradation of stream habitat through logging or wildfire
SeverityLow - Low but nontrivial reduction of species population or reversible degradation or reduction of habitat in area affected, with recovery expected in 10-50 years.
CommentGiven current forest management practices, impacts should not persist for more than 50 years
ScopeLow - 5-20% of total population or area affected
CommentSpecies is found across a large area so impact to large portions of the population would be unlikely
ImmediacyLow - Threat is likely to be operational within 5-20 years.
CommentPossible within the next 20 years, but is not imminent.
ScoreB - Moderately Vulnerable. Species exhibits moderate age of maturity, frequency of reproduction, and/or fecundity such that populations generally tend to recover from decreases in abundance over a period of several years (on the order of 5-20 years or 2-5 generations); or species has moderate dispersal capability such that extirpated populations generally become reestablished through natural recolonization (unaided by humans).
CommentThis species has high fecundity, a moderate age of maturity, and recruitment can be low.
ScoreB - Narrow. Specialist. Specific habitat(s) or other abiotic and/or biotic factors (see above) are used or required by the Element, but these key requirements are common and within the generalized range of the species within the area of interest.
CommentSpecies is associated with montane streams within forested areas across western Montana.
Raw Conservation Status Score
3.5 + 0 (geographic distribution) + 0 (environmental specificity) + 0 (long-term trend) + 0.75 (threats) = 4.25
Laid in a jelly string as a globular mass containing 28 to 86 eggs (Noble and Putnam 1931; Franz
1970a). Each ovum is creamy white and surrounded by two jelly layers which themselves lie
within the outer jelly string (Franz 1970a). Ovum diameters are approximately 4-5 mm, but total egg diameters, including the three jelly layers, are approximately 6-7 mm (Metter 1967, Adams 1993). Clutches from multiple animals may be laid together in the same nest site (Adams 1993).
Base color is variable from solid black, to gray, to solid brown. White flecks may be present and
most larvae have a white tail spot (Metter 1967). A large sucking disk is present around the
mouth. The spiracle is mid-ventral and opens under a flap (Metter 1968). Total length (TL) of
10-64 mm (up to 2 inches long) (Metter 1967, Franz 1971).
JUVENILES AND ADULTS
Pupil of the eye is vertical. This species lacks external ear drums (tympanums). The cloaca of males opens into a tear-shaped copulatory organ (the “tail”). Skin is a granulated texture. Base color is brown, reddish brown, or olive gray with yellow and gray mottling dorsally and a dark eye stripe. Ventrally cream to pinkish. The outer toe of the hind foot is broader than the other toes. Snout-vent length (SVL) of 20-57 mm (1.5-2 inches) (Daugherty 1979, Daugherty and Sheldon 1982a).
No other adult anuran species lack external ear drums (tympanums). No other larval anuran species have a large sucking disk around the mouth or are found in small swift streams.
Western Hemisphere Range
Until recently tailed frogs were recognized as a single species with a disjunct distribution. The coastal population, ranging from northwestern California to southwestern British Columbia separated by hundreds of miles from a Rocky Mountain population that includes isolated populations in the Blue, Wallowa and Seven Devils Mountains and a more continuous population that ranges from central Idaho to the southeast corner of British Columbia (Metter 1968a). However, allozyme and mitochondrial DNA analyses indicate that the Rocky Mountain and coastal populations differ to the extent that a separate species designation is warranted (Daugherty 1979, Nielson and Lohman 2000, Maxell et al. 2009). Populations in the Rocky Mountains and those in the Blue, Wallowa and Seven Devils Mountain Ranges are now recognized as the Rocky Mountain Tailed Frog (Ascaphus montanus) and coastal populations are now recognized as the Coastal Tailed Frog (Ascaphus truei) (Mittleman and Myers 1949, Maxell et al. 2009). Across their entire range, the Rocky Mountain Tailed Frogs are known to occur at elevations up to 2,590 m (8,500 ft), or approximately up to the treeline (Nussbaum et al. 1983, Maxell 2009).
Maximum elevation: 2,661 m (8,729 ft) on unnamed tributary to Halfway Creek in the Pioneer Mountains in Beaverhead County (B. Murdock; MTNHP 2007).
Observations in Montana Natural Heritage Program Database
Number of Observations:
(Click on the following maps and charts to see full sized version)
Map Help and Descriptions
(Observations spanning multiple months or years are excluded from time charts)
Non-migratory. Has no breeding migration (Daugherty 1982).
Rocky Mountain Tailed Frogs are found in and along small (< 4.5 m width), fast permanent forested streams with clear, cold water, cobble or boulder substrates, and little silt (Franz and Lee 1970, Franz 1971, Welsh 1990). In the Flathead area, larvae are found only in streams with temperature under 16 °C. They prefer fast streams, less than 14 ft wide, with substrate of slabby-flat bottomed rocks with little aquatic vegetation (Franz and Lee 1970).
Larvae feed mostly on diatoms, but also algae and small aquatic insects (Franz 1970b). Adults are opportunistic and forage mainly at night in forest near streams on a variety of aquatic and terrestrial invertebrates (Metter 1964b, Bury 1970).
In Montana, adults usually remain underwater hidden by rocks or debris and emerge at night or during humid weather from May to September to feed terrestrially along stream edges (Daugherty and Sheldon 1982a). Tadpoles cling to the undersides or tops of smooth rocks which lack periphyton or silt (Nussbaum et al. 1983). Adults are highly philopatric but are known to forage up to 75 m away from water in Montana (Daugherty and Sheldon 1982b, Maxell et al. 2009). However, they may range farther from water in wetter areas. Gomez and Anthony (1996) found them in pitfall traps 200 m from streams in the Oregon Cascades and Corn and Bury (1990) found juveniles and adults ranging more than 300 m from the nearest stream west of the Cascade Mountains in Oregon and Washington. At high elevations in Montana, adults and juveniles have been found to be active diurnally in warmer standing water bodies 50-75 m away from streams during warm dry weather (Maxell et al. 2009). American Dippers (Cinclus mexicanus
) have been documented predating on the closely related species Coastal Tailed Frog (Ascaphus truei
) (Morrissey and Olenick 2004).
In Montana, adults breed via internal fertilization in streams during August or September. Females store sperm overwinter (Metter 1964b) and ovipost eggs under large stones in areas with slight current the following June or July (Franz 1970a, Daugherty and Sheldon 1982a). Eggs hatch in August or September but remain in nest (under rocks in stream) until the yolk is consumed (October to November). Development of eggs under natural conditions is discussed by Franz (1970b). Tadpoles usually metamorphose in the third summer after hatching in July to September. In Montana, adults reproduce for the first time four or five years after metamorphosis (age 7-8) which is the latest of any North American amphibian. Females reproduce in alternate years thereafter (Daugherty 1979, Daugherty and Sheldon 1982a). Because of this species extremely philopatric nature, likely that there is very little gene flow between populations (Daugherty 1982).
The following was taken from the Status and Conservation section for the Rocky Mountain Tailed Frog account in Maxell et al. 2009
Rocky Mountain Tailed Frogs are widely distributed and common west of the Continental Divide in smaller streams that have adequate amounts of cobble substrates. Their status in the front ranges east of the Continental Divide is uncertain. Risk factors relevant to the viability of populations of this species are likely to include all the general risk factors described above (especially those which change stream morphology, and increase sedimentation and water temperature), with the exception of harvest and commerce. Individual studies that specifically identify risk factors or other issues relevant to the conservation of tailed frogs include the following. (1) Although the impacts of timber harvest have not been studied in Montana, numerous studies have documented the extirpation of Rocky Mountain Tailed Frogs at a number of locations in the Pacific Northwest as a result of increased sedimentation and water temperature resulting from timber harvest and associated road building activities (Metter 1964, Bury 1983, Bury and Corn 1988, Welsh and Lind 1988, Corn and Bury 1989, Corn and Bury 1990, Welsh 1990, Bull and Carter 1996a). Because Rocky Mountain Tailed Frogs are highly philopatric, have limited dispersal capabilities, and are apparently somewhat reliant on old growth forests, streams they have been extirpated from may not be recolonized for extensive periods of time after timber harvest activities (Metter 1967, Daugherty and Sheldon 1982a, Corn and Bury 1989, Welsh 1990). Furthermore, some of these same studies found that even if Rocky Mountain Tailed Frogs were still present after timber harvest their density and biomass were negatively affected. Additionally, density and biomass were lower in younger stands than older stands (e.g., Corn and Bury 1990, Welsh 1990, Gomez and Anthony 1996). A study in the Blue Mountains of Oregon provides evidence that stream buffers do provide protection for Rocky Mountain Tailed Frogs in drier forests similar to those found across much of Montana. Bull and Carter (1996a) found that the number of Rocky Mountain Tailed Frogs was best predicted by a combination of stream substrates and the presence of stream buffers. (2) Although the impacts of piscicides have not been formally investigated, anecdotal evidence from treated areas in Montana suggests they may have major population-level impacts on Rocky Mountain Tailed Frogs (Andrew Sheldon, University of Montana, personal communication). Fontenot et al. (1994) and McCoid and Bettoli (1996) recently reviewed the impacts of rotenone-containing piscicides on amphibians and found that the effects of rotenone on newly metamorphosed and adult amphibians varied with the degree of each species’ aquatic respiration and their likelihood of exiting treated water bodies. They found the range of lethal doses of rotenone-containing piscicides for amphibian larvae (0.1-0.580 mg/L) to overlap to a large extent with lethal doses for fish (0.0165-0.665 mg/L), and to be much lower than the concentrations commonly used in fisheries management (0.5-3.0 mg/L). The nontarget effects of another piscicide, antimycin, have apparently not been formally studied, but preliminary observations seem to indicate that antimycin is also toxic to amphibian larvae (Patla 1998b). Tailed frog larvae and adults both use aquatic respiration and adults are unlikely to exit treated water bodies depending on the time of day (Daugherty and Sheldon 1982b).
- Literature Cited AboveLegend: View Online Publication
- Adams, M.J. 1993. Summer nests of the tailed frog (Ascaphus truei) from the Oregon coast range. Northwestern Naturalist 74: 15-18.
- Bull, E.L. and B.E. Carter. 1996a. Tailed frogs: distribution, ecology, and association with timber harvest in northeastern Oregon. USDA Forest Service, Research Paper PNW-RP-497, Portland, Oregon. 17p.
- Bury, R.B. 1970. Food similarities in the tailed frog, Ascaphus truei, and the Olympic salamander, Rhyacotriton olympicus. Copeia 1970: 170-171.
- Bury, R.B. 1983. Differences in amphibian populations in logged and old growth redwood forest. Northwest Science. 57(3): 167-178.
- Corn, P.S. and R.B. Bury. 1989. Logging in western Oregon: responses of headwater habitats and stream amphibians. For. Ecol. and Manage. 29:39-57.
- Corn, P.S. and R.B. Bury. 1990. Sampling methods for terrestrial amphibians and reptiles. General Techinical Report PNW-GTR 256, USDA, Forest Service. 34 p.
- Daugherty, C.H. 1979. Population ecology and genetics of Ascaphus truei: an examination of gene flow and natural selection. Ph.D. dissertation, University of Montana. Missoula, MT. 143 pp.
- Daugherty, C.H. and A.L. Sheldon. 1982a. Age-determination, growth, and life history of a Montana population of the tailed frog Ascaphus truei. Herpetologica 38(4): 461-468.
- Daugherty, C.H. and A.L. Sheldon. 1982b. Age specific movement patterns of the frog Ascaphus truei. Herpetologica 38(4):468-474.
- Fontenot, L.W., G.P. Noblet and S.G. Platt. 1994. Rotenone hazards to amphibians and reptiles. Herpetological Review 25(4):150-156.
- Franz, R. 1970a. Egg development of the tailed frog under natural conditions. Bulletin of the Maryland Herpetological Society 6(2): 27-30.
- Franz, R. 1970b. Food of larval tailed frogs. Bulletin of the Maryland Herpetological Society 6: 49-51.
- Franz, R. 1971. Notes on the distribution and ecology of the herpetofauna of northwestern Montana. Bulletin of the Maryland Herpetological Society 7: 1-10.
- Franz, R. and D.S. Lee. 1970. The ecological and biogeographical distribution of the tailed frog, Ascaphus truei, in the Flathead River drainage of northwestern Montana. Bulletin of the Maryland Herpetological Society 6: 62-73.
- Gomez, D.M. and R.G. Anthony, R. G. 1996. Amphibian and reptile abundance in riparian and upslope areas of five forest types in Western Oregon. Northwest Science 70(2):109-119.
- Maxell, B.A., P. Hendricks, M.T. Gates, and S. Lenard. 2009. Montana amphibian and reptile status assessment, literature review, and conservation plan, June 2009. Montana Natural Heritage Program. Helena, MT. 643 p.
- McCoid, M.J. and P.W. Bettoli. 1996. Additional evidence for rotenone hazards to turtles and amphibians. Herpetological Review 27(2): 70-71.
- Metter, D.E. 1964a. A morphological and ecological comparison of two populations of the tailed frog Ascaphus truei Stejneger. Copeia 1964: 181-195.
- Metter, D.E. 1964b. On breeding and sperm retention in Ascaphus. Copeia 1964(4): 710-711.
- Metter, D.E. 1967. Variation in the ribbed frog Ascaphuss truei Stejneger. Copeia 1968: 634-649.
- Metter, D.E. 1968a. Ascaphus and Ascaphus truei. Catalogue of American Amphibians and Reptiles. Pp 69.1-69.2.
- Mittleman, M.B. and G.S. Meyers. 1949. Geographical variation in the ribbed frog Ascaphus truei. Proceedings of the Biological Society of Washington 62: 57-68.
- Morrissey, Christy A., and Roberta J. Olenick. 2004. American Dipper, Cinclus mexicanus, preys upon larval taild frogs, Ascaphus truei. Canadian Field-Naturalist 118(3): 446-448.
- Nielson, M. and K. Lohman. 2000. Genetic structure within an ancient lineage: the phylogeography of tailed frogs (Ascaphus truei). Northwest Sectional Meeting of The Wildlife Society, University of Idaho, Moscow, Idaho. p. 22.
- Noble, G.K., and P.G. Putnam. 1931. Observations on the life history of Ascaphus truei Stejneger. Copeia 1931(3): 97-101.
- Nussbaum, R.A., E.D. Brodie, Jr. and R.M. Storm. 1983. Amphibians and reptiles of the Pacific Northwest. University of Idaho Press. Moscow, ID. 332 pp.
- Patla, D.A. 1998b. Potential effects of native fish restoration projects on amphibians in Yellowstone National Park Part I. Report to National Park Service, Yellowstone National Park. 20 November 1998. 26 pp.
- Welsh, H. H., Jr. 1990. Relictual amphibians and old-growth forests. Conservation Biology 4: 309-319.
- Welsh, H.H. Jr. and A.J. Lind. 1988. Old growth forests and the distribution of the terrestrial herpetofauna. U.S. Forest Service, Rocky Mountain Forest and Range Experiment Station, Fort Collins, Colorado. General Technical Report RM-166: 439-458.
- Additional ReferencesLegend: View Online Publication
Do you know of a citation we're missing?
- [USFWS] US Fish and Wildlife Service. 1994. Endangered and threatened wildlife and plants; animal candidate review for listing as endangered or threatened species. Federal Register 59(219): 58982-59028.
- Adams, S. 1998. Tailed frog migration: a local response to seasonally unsuitable habitat? Abstract. Montana Chapter of the American Fisheries Society Meeting. Helena, MT. February 2-5, 1998.
- Adams, S. and C.A. Frissell. 2001. Thermal habitat use and evidence of seasonal migration by Rocky Mountain tailed frogs, Ascaphus montanus, in Montana. Canadian Field Naturalist 115(2): 251-256.
- Altig, R. 1969. Notes on the ontogeny of the osseous cranium of Ascaphus truei. Herpetelogica 25:59-62.
- Altig, R., and E.E. Brodie. 1972. Laboratory behavior of Ascaphus truei tadpoles. Journal of Herpetology 6: 21-24.
- Black, J.H. and J.N. Black. 1968. Frog with a tail. Montana Outdoors 3(3): 3 p.
- Black, J.H. and R. Timken. 1976. Endangered and threatened amphibians and reptiles in Montana. p 36–37. In R.E. Ashton, Jr. (chair). Endangered and threatened amphibians and reptiles in the United States. Society for the Study of Amphibians and Reptiles Herpetological Circular 5: 1-65.
- Blaustein, A.R., J.J. Beatty, H. Deanna, and R.M. Storm. 1995. The biology of amphibians and reptiles in old-growth forests in the Pacific Northwest. General Technical Report PNW-GTR-337. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 98 p.
- Bogart, J.P., E.K. Balon, and M.N. Bruton. 1994. The chromosomes of the living coelacanth and their remarkable similarity to those of one of the most ancient frogs. Journal of Heredity 85(4): 322-325.
- Boundy, J. 2001. Herpetofaunal surveys in the Clark Fork Valley region, Montana. Herpetological Natural History 8: 15-26.
- Brown, H.A. 1975b. Temperature and development of the tailed frog (Ascaphus truei). Comparative Biochemistry and Physiology 50A: 397-405.
- Brown, H.A. 1989a. Developmental anatomy of the tailed frog (Ascaphus truei): a primitive frog with large eggs and slow development. Journal of Zoology London 217: 525-537.
- Brown, H.A. 1990a. Morphological variation and age-class determination in overwintering tadpoles of the tailed frog, Ascaphus truei. Journal of Zoology 220: 171-184.
- Brown, H.A. 1990b. Temperature, thyroxine, and induced metamorphosis in tadpoles of a primitive frog, Ascaphus truei. General and Comparative Endocrinology 79(1): 136-146.
- Brunson, R.B. 1955. Check list of the amphibians and reptiles of Montana. Proceedings of the Montana Academy of Sciences 15: 27-29.
- Brunson, R.B. and H.A. Demaree, Jr. 1951. The herpetology of the Mission Mountains, Montana. Copeia (4):306-308.
- Bull, E.L. and B.E. Carter. 1996b. Winter observations of tailed frogs in northeastern Oregon. Northwestern Naturalist 77: 45-47.
- Burkholder, L.L. 2003. Seasonal activity patterns and life history characteristics of post-metamorphic tailed frogs in north coastal California. Abstract. Northwestern Naturalist 84:96.
- Bury, R.B. 1968. The distribution of Ascaphus truei in California. Herpetologica 24(1): 39-46.
- Bury, R.B. and M.J. Adams. 1999. Variation in age at metamorphosis across a latitudinal gradient for the tailed frog (Ascaphus truei). Herpetologica 55(2): 283-291.
- Bury, R.B., G.M. Fellers, and S.B. Ruth. 1969. First records of Plethodon dunni in California, and new distributional data on Ascaphus truei, Rhyacotriton olympicus, and Hydromantes shastae. Journal of Herpetology 3: 157-161.
- Bury, R.B., P. Loafman, D. Rofkar, and K.I. Mike. 2001. Clutch sizes and nests of tailed frogs from the Olympic Peninsula, Washington. Northwest Science 75(4): 419-422.
- Carlson, J. (Coordinator, Montana Animal Species of Concern Committee). 2003. Montana Animal Species of Concern. Helena, MT: Montana Natural Heritage Program and Montana Fish, Wildlife, and Parks. In Press. 12p.
- Cavallo, B.J. 1997. Floodplain habitat heterogeneity and the distribution, abundance, and behavior of fishes and amphibians in the Middle Fork Flathead River Basin, Montana. M.S. Thesis. University of Montana, Missoula, MT. 133 p.
- Clancy, C.G. 1996. Statewide fisheries investigations, Bitterroot Forest inventory July 1, 1995 to June 30, 1996. Job completion report. Montana Department of Fish, Wildlife and Parks, Fisheries Division. 97 p.
- Claussen, D.L. 1971. A comparative study of the thermal and water relations of the tailed frog, Ascaphus truei and the Pacific treefrog, Hyla regilla. Ph.D. Dissertation. University of Montana, Missoula, MT. 103 p.
- Claussen, D.L. 1973a. The thermal relations of the tailed frog (Ascaphus truei) and the Pacific treefrog (Hyla regilla). Comparative Biochemistry and Physiology 44a: 137-153.
- Claussen, D.L. 1973b. The water relations of the tailed frog (Ascaphus truei) and the Pacific treefrog (Hyla regilla). Comparative Biochemistry and Physiology 44a: 155-171.
- Cochran, D.C. 1961. Type specimens of reptiles and amphibians in the United States National Museum. U.S. National Museum Bulletin (220) xv + 291pp.
- Corbit, C.D. 1960. Range extensions of Ascaphus truei in Idaho. Copeia 1960: 240.
- Crother, B.I. (ed.) 2008. Scientific and standard English names of amphibians and reptiles of North America north of Mexico. SSAR Herpetological Circular No. 37:1-84.
- Daugherty, C.H. 1976. Freeze-branding as a technique for marking anurans. Copeia 1976: 836-838.
- Daugherty, C.H. and F.W. Allendorf. 1977a. Divergence of populations: preliminary evidence relating to the Ehrlich-Raven hypothesis from Ascaphus truei. Abstract. Annual Report Issue of the Genetics Society of America 86(2): S14.
- Daugherty, C.H. and F.W. Allendorf. 1977b. The taxonomic value of genetic distance: data from two amphibians. Abstract. American Zoologist 17(4): 973.
- Daugherty, C.H. and F.W. Allendorf. 1979. Temporal genetic stability in a population of the tailed frog, Ascaphus truei. Abstract. American Zoologist 19(3): 962.
- Daugherty, C.H., L.N. Wishard, and L.B. Daugherty. 1978. Sexual dimorphism in an anuran response to severe thermal stress. Journal of Herpetology 12(3): 431-432.
- De Vlaming, V.L., and R.B. Bury. 1970. Thermal selection in tadpoles of the tailed frog, Ascaphus truei. Journal of Herpetology 4: 179-189.
- Diller, L.V. and R.L. Wallace. 1999. Distribution and habitat of Ascaphus truei in streams on managed, young growth forests in north coastal California. Journal of Herpetology 33(1): 71-79.
- Donaldson, L.R. 1934. The occurrence of Ascaphus truei east of the Continental Divide. Copeia 1934(4): 184.
- Dupuis, L.A. and D. Steventon. 1999. Riparian management and the tailed frog in northern coastal forests. Journal of Forest Ecology and Management 124(1): 35-43.
- Dupuis, L.A. and F.L.Bunnell. 1999. Status and distribution of the tailed frog in British Columbia. A report for Forest Renewal British Columbia, Victoria, British Columbia.
- Dupuis, L.A. and P. Friele. 2004. River continuum concept and management efforts--The case of the tailed frog. Abstract. Northwestern Naturalist 85:73.
- Dupuis, L.A., F.L.Bunnell,and P.A. Friele. 2000. Determinants of the tailed frog's range in British Columbia, Canada. Northwest Science 74(2): 109-115.
- Enk, M. 1999. Preliminary results of amphibian monitoring on the Lewis and Clark National Forest. Intermountain Journal of Sciences 5(1-4): 48.
- Farmer, P. and S.B. Heath. 1987. Wildlife baseline inventory, Rock Creek study area, Sanders County, Montana. Western Technology and Engineering, Inc. Helena, MT.
- Feminella, J.W. and C.P. Hawkins. 1994. Tailed frog tadpoles differentially alter their feeding behavior in response to non-visual cues from four predators. Journal of the North American Benthological Society 13: 310-320.
- Flath, D.L. 1998. Species of special interest or concern. Montana Department of Fish, Widlife and Parks, Helena, MT. March, 1998. 7 p.
- Flath, D.L. 1979. Nongame species of special interest or concern: Mammals, birds, reptiles, amphibians, fishes. Wildlife Division, Montana Department of Fish and Game. Helena, MT.
- Fraley, J. 2001. Frog with a tail. Montana Outdoors 32(2): 21-22.
- Franklin, T.W., T.M. Wilcox, K. S. McKelvey, S.E. Greaves, J.C. Dysthe, M.K. Young, M.K. Schwartz, and J. Lindstrom. 2019. Repurposing Environmental DNA Samples to Verify the Distribution of Rocky Mountain Tailed Frogs in the Warm Springs Creek Basin, Montana. Northwest Science 93(1):85-92.
- Fritzsch, B., R.C. Drewes and R. Ruibal. The retention of the lateral-line nucleus in adult anurans. Copeia 1987: 127-135.
- Gaige, H.T. 1920. Observations upon the habitats of Ascaphus truei Stejneger. Occassional Papers of the University of Michigan Museum of Zoology 84: 1-9, pl. 1.
- Galloway, B.T. 2014. Feasibility assessment for translocation of imperiled Bull Trout populations in Glacier National Park, Montana. M.Sc. Thesis. Bozeman, MT: Montana State University. 110 p.
- Gradwell, N. 1971. Ascaphus tadpole: experiments on the suction and gill irrigation mechanisms. Canadian Journal of Zoology 49: 307-332.
- Gradwell, N. 1973. On the functional morphology of suction and gill irrigation in the tadpole of Ascaphus, and notes on hibernation. Herpetologica 29: 84-93.
- Gray, L.A. 1992a. Age determination and age at metamorphosis of the tailed frog, Ascaphus truei. Northwest Science 66(2): 115.
- Gray, L.A. 1992b. Larval growth and age at completion of metamorphosis of the tailed frog, (Ascaphus truei). Ellensburg, WA: Central Washington University. 62p. M.S. Thesis.
- Green, D.M., C.H. Daugherty, and J.P. Bogart. 1980. Karyology and systematic relationships of the tailed frog (Ascaphus truei). Herpetologica 36: 346-352.
- Green, D.M., T.F. Sharbel, R.A. Hitchmough and C.H. Daugherty. 1989. Genetic variation in the genus Leiopelma and relationships to other primitive frogs. Zeitschrift Fuer Zoologische Systematik und Evolutionforschung 27(1): 65-79.
- Hailman, J.P. 1982. Extremely low ambient light levels of Ascaphus truei. Journal of Herpetology 16: 83-84
- Hailman, J.P. and R.G. Jaeger. 1974. Phototactic responses to spectrally dominant stimuli and use of colour vision by adult anuran amphibians: a comparative survey. Animal Behavior 22: 757-795
- Hailman, J.P. and R.G. Jaeger. 1978. Photactic responses of anuran amphibians to monochromatic stimuli of equal quantum intensity. Animal Behavior 26: 274-281
- Hanauska-Brown, L., B.A. Maxell, A. Petersen, and S. Story. 2014. Diversity Monitoring in Montana 2008 – 2010 Final Report. Montana Fish, Wildlife & Parks. Helena, MT. 78 pp.
- Hansen, B.P., D.H. Olson, and C.D. Moyer. 2000. Demographics and age at metamorphosis of larval tailed frogs, Ascaphus truei, in a coastal Oregon stream. Northwestern Naturalist 81(2):75.
- Hawkins, C.P. and J.R. Sedell. 1990. The role of refugia in the recolonization of streams devastated by the 1980 eruption of Mount St. Helens. Northwest Science 64(5): 271-274.
- Hawkins, C.P., J. Feminella and C.M. Crissafulli. 1994. Patterns of abundance and growth of tailed frog populations near the Mt. St. Helens blast Zone. Northwest Science 68(2): 129.
- Hawkins, C.P., L.J. Gottschalk, and S.S. Brown. 1988. Densities and habitat of tailed frog tadpoles in small streams near Mt. St. Helens following the 1980 eruption. Journal of the North American Benthological Society 7: 246-252.
- Hayes, M.P., D.J. Dugger, T.L. Hicks, and T. Quinn. 2003b. Headwater habitat variation: Its relationship to stream amphibian distribution. Abstract. Northwestern Naturalist 84:100.
- Hayes, M.P., T. Quinn, D.E. Runde, L.L.C. Jones, M.G. Raphael, and T. Hicks. 2002. Is the Olympic tailed frog (Ascaphus truei) a biodiversity indicator? Northwestern Naturalist 83(2):71.
- Hazelwood, W.G. 1993. Extending the known range of tailed frog populations in British Columbia. Unpublished report. Alpenglow Resources, Terrace, British Columbia.
- Held, S.P. 1984. Captive maintenance of the tailed frog (Ascaphus truei) at the Washington Park Zoo, Portland Oregon. Animal Keepers’ Forum 11(12): 402-410.
- Held, S.P. 1985. Maintenance, exhibition, and breeding of the tailed frog, Ascaphus truei, in a zoological park. Herpetological Review 16(2): 48-51.
- Hendricks, P. 1997. Lee Metcalf National Wildlife Refuge preliminary amphibian and reptile investigations: 1996. Montana Natural Heritage Program, Helena, MT. 21 p.
- Hendricks, P. and J.D. Reichel. 1996a. Amphibian and reptile survey of the Bitterroot National Forest: 1995. Montana Natural Heritage Program. Helena, MT. 95 p.
- Hossack, B.R. 2006. Amphibians and wildfire in the U.S. Northwest. International Journal of Wilderness 12(1):26.
- Hossack, B.R. and P.S. Corn. 2005. Changes in counts of Rocky Mountain tailed frog tadpoles after wildfires in Glacier National Park, Montana. Abstract. Northwestern Naturalist 86:99.
- Jaeger, R.G. and Hailman, J.P. 1973. Effects of intensity on the phototactic responses of adult anuran amphibians: a comparative survey. Zoological Tierpsychology 33: 352-407.
- Jamieson, B.G.M., M.S.Y. Lee and K. Long. 1993. Ultrastructure of the spermatozoon of the internally fertilizing frog Ascaphus truei (Ascaphidae: Anura: Amphibia) with phylogenetic considerations. Herpetologica 49(1): 52-65.
- Jones L.C. and M.G. Raphael. 1998. Ascaphus truei (Tailed frog). Predation. Herpetological Review 29: 39.
- Jones, J.L., C.R. Peterson, and C.V. Baxter. 2006. Factors influencing Rocky Mountain tailed frog (Ascaphus montanus) distribution and abundance. Department of Biological Sciences Idaho State University. pp. 25 plus tables.
- Jones, Lawrence L. C., W. P. Leonard and D. H. Olson, eds. 2005. Amphibians of the Pacific Northwest. Seattle Audubon Society: Seattle, WA, 227 pp.
- Karraker, N.E. 2001. Ascaphus truei (tailed frog) predation. Herpetological Review 32(2): 100.
- Karraker, N.E., and G.S. Beyersdorf. 1997. A tailed frog (Ascaphus truei) nest site in northwestern California. Northwestern Naturalist 78(3): 110-111.
- Karraker, N.E., D.S. Pilliod, E.L. Bull, S.P. Corn, L.V. Diller. 2004. Taxonomic and geographic variation in the oviposition of tailed frogs (Ascaphus spp.). Abstract. Northwestern Naturalist 85:79.
- Kelsey, K.A. 1994. Responses of headwater stream amphibians to forest practices in western Washington. Northwest Science 68(2): 133.
- Lamberti, G.A., S.V. Gregory, and C.P. Hawkins. 1988. Of frogs and phyton: the importance of herbivory in devastated streams of Mount St. Helens. Bulletin of the Ecological Society of America 69(2): 201.
- Landreth, H.F. and D.E. Ferguson. 1967. Movements and orientation of the tailed frog, Ascaphus truei. Herpetologica 23: 81-93.
- Lapsansky, J.M. and H.A. Brown. 1992. Oviduct histology and sperm storage in the tailed frog (Ascaphus truei). American Zoologist 32(5):147A.
- Lohman, K. 2000. Temporal and spatial variability in the abundance of tailed frog tadpoles (Ascaphus truei) in a Nothern Idaho watershed. Northwestern Naturalist 81(2):81.
- Lohman, K. 2000. Temporal and spatial variability in the abundance of tailed frog tadpoles (Ascaphus truei) in streams of the Mica Creek Experimental Watershed. Northwest Sectional Meeting of The Wildlife Society, University of Idaho, Moscow, Idaho. p
- Manville, R.H. 1957. Amphibians and reptiles of Glacier National Park, Montana. Copeia 1957: 308-309.
- Marnell, L. E. 1997. Herpetofauna of Glacier National Park. Northwestern Naturalist 78:17-33.
- Marnell, L.F. 1996. Amphibian survey of Glacier National Park, Montana. Abstract. Intermountain Journal of Sciences 2(2): 52.
- Matsuda, B.M. and J.S. Richardson. 2000. Assessing the effects of clear-cut timber harvest on the movement patterns tailed frogs (Ascaphus truei) in southwestern British Columbia. Northwestern Naturalist 81(2):82.
- Maughan, O.E, P. Laumeyer, R.L. Wallace, and M.G. Wickham. 1980. Distribution of the tailed frog, Ascaphus truei Stejneger, in several drainages in northcentral Idaho. Herpetological Review 11(1): 15-16.
- Maxell, B. A. 2000. Management of Montana's amphibians: a review of factors that may present a risk to population viability and accounts on the identification, distribution, taxonomy, habitat use, natural history, and the status and conservation of individual species. Report to USFS Region 1, Order Number 43-0343-0-0224. University of Montana, Wildlife Biology Program. Missoula, MT. 161 p.
- Maxell, B.A. 2002a. Amphibian and aquatic reptile inventories in watersheds in the South and Middle Forks of the Flathead River drainage that contain lakes being considered for application of piscicides and subsequent stocking of west slope cutthroat trout. Report to the Region 1 Office of the U.S. Forest Service and the Montana Department of Fish, Wildlife, and Parks. Montana Cooperative Wildlife Research Unit and Wildlife Biology Program, University of Montana, Missoula, MT. 62 pp.
- Maxell, B.A., J.K. Werner, P. Hendricks, and D.L. Flath. 2003. Herpetology in Montana: a history, status summary, checklists, dichotomous keys, accounts for native, potentially native, and exotic species, and indexed bibliography. Society for Northwestern Vertebrate Biology, Northwest Fauna Number 5. Olympia, WA. 135 p.
- Metter, D.E. 1963. Stomach contents of Idaho larval Dicamptodon. Copeia (2): 435-436.
- Metter, D.E. 1963a. A morphological and ecological comparison of two populations of Ascaphus truei Stejneger. Ph.D. Dissertation, University of Idaho. 73 pp.
- Metter, D.E. 1966. Some temperature and salinity tolerances of Ascaphus truei Stejneger. Journal of Idaho Academy of Sciences 4: 44-47.
- Metter, D.E. 1968b. The influence of floods in the population structure of Ascaphus truei Stejneger. Journal of Herpetology 1: 105-106.
- Metter, D.E. and R.J. Pauken. 1969. An analysis of the reduction of gene flow in Ascaphus truei in the northwest U.S. since the Pleistocene. Copeia 1969: 301-307.
- Morgan, G.T. and K.M. Middleton. 1988. Organization and sequence of the compact ribosomal DNA spacer of the tailed frog, Ascaphus-truei. Nucleic Acids Research 16(22): 10917.
- Morgan, G.T. and K.M. Middleton. 1992. Conservation of intergenic spacer length in ribosomal DNA of the tailed frog, Ascaphus truei. Gene (Amsterdam) 110(2): 219-223.
- Myers, G.S. 1931. Ascaphus truei in Humboldt County, California, with a note on the habits of the tadpole. Copeia 1931: 56-67.
- Myers, G.S. 1943. Notes on Rhyacotriton olympicus and Ascaphus truei in Humboldt County, California. Copeia 1943: 125-126.
- Nielson, M., K. Lohman, and J. Sullivan. 2001. Phylogeography of the tailed frog (Ascaphus truei): implications for the biogeography of the Pacific Northwest. Evolution 55: 147-160.
- Nielson, M.K. 2000. Phylogeography of the tailed frog (Ascaphus truei) : implications for the biogeography of the Pacific Northwest and a taxonomic revision within Ascaphus. M.S. Thesis. Department of Fish and Wildlife Resources, University of Idaho, Moscow, ID. 82 p.
- Nishikawa, K.C. 1991. Kinematics of prey capture in the tailed frog Ascaphus truei (Anura: Ascaphidae). Zoological Journal of the Linnean Society 103(3): 289-307.
- Noble, G.K. 1922. Editorial note on Asacaphus truei. Copeia 102: 6.
- Northrop, Devine & Tarbell, Inc. 1994. Cabinet Gorge and Noxon Rapids hydroelectric developments: 1993 wildlife study. Unpublished report to the Washington Water Power Company, Spokane. Vancouver, Washington and Portland, Maine. 144 pp. plus appendices.
- Pauken, R.J. and D.E. Metter. 1971. Geographic representation of morphologic variation among populations of Ascaphus truei Stejneger. Systematic Zoology 20: 434-441.
- Pilliod, D.S. and P.S. Corn. 2003. Changes in stream amphibian populations following large fires in Idaho. Abstract. Northwestern Naturalist 84:110.
- Pilliod, D.S. and P.S. Corn. 2004. Effects of wildfires on stream amphibian populations in the greater Northwest. Abstract. Northwestern Naturalist 85:85.
- Pusey, H.K. 1943. On the head of the liopelmid frog Ascaphus truei. Quarterly Journal of Microscopical Science 84: 105-185.
- Putman, P.J. 1931. Life history and habits of Ascaphus truei. Unpublished M.S. Thesis, Washington State University Library.
- Reichel, J. and D. Flath. 1995. Identification of Montana's amphibians and reptiles. Montana Outdoors 26(3):15-34.
- Reichel, J.D. 1996. Preliminary amphibian and reptile survey of the Helena National Forest: 1995. Montana Natural Heritage Program. Helena, MT. 87 pp.
- Reichel, J.D. 1997a. Amphibian, reptile and northern bog lemming survey on the Rocky Mountain Front: 1996. Montana Natural Heritage Program, Helena, MT. 81 p.
- Reichel, J.D. 1995a. Preliminary amphibian and reptile survey of the Lewis and Clark National Forest: 1994. Montana Natural Heritage Program. Helena, MT. 92 p.
- Rich, C.F. 1996. Influence of abiotic and biotic factors on occurrence of resident Bull Trout in fragmented habitats, western Montana. M.Sc. Thesis. Bozeman, MT: Montana State University. 44 p.
- Ritland, K., L.A. Dupuis, F.L. Bunnell, W.L.Y. Hung, and J.E. Carlson. 2000. Phylogeography of the tailed frog (Ascaphus truei). Canadian Journal of Zoology 78: 1749-1758.
- Ritland, R.M. 1955. Studies on the post-cranial morphology of Ascaphus truei. (I) skeleton and spinal nerves. Journal of Morphology 97: 119-177.
- Rodgers, T. L. and W. L. Jellison. 1942. A collection of amphibians and reptiles from western Montana. Copeia (1):10-13.
- Roedel, M.D. and P. Hendricks. 1998. Amphibian and reptile survey on the Bureau of Land Management Lewistown District: 1995-1998. Montana Natural Heritage Program, Helena, MT. 53 p.
- Roedel, M.D. and P. Hendricks. 1998b. Amphibian and reptile inventory on the Headwaters and Dillon Resource Areas in conjunction with Red Rocks Lakes National Wildlife Refuge: 1996-1998. Montana Natural Heritage Program, Helena, MT. 46 p.
- Roper, B.B. and D.L. Scarnecchia. 2001. Patterns of diversity, density, and biomass of ectothermic vertebrates in ten small streams along a North American river continuum. Northwest Science 75(2): 168-175.
- Rundio, D.E. and C.P. Hawkins. 2000. Effects of tailed frog tadpole density on tadpole growth, invertebrate abundance, and algal abundance. Northwestern Naturalist 81(2):87.
- Schell, S.C. 1964. Bunoderella metteri gen. and sp. N. (Trematoda: Allocreadiidae) and other trematode parasites of Ascaphus truei Stejneger. Journal of Parasitology 50(5): 652-655.
- Schell, S.C., G. Anderson and I. Pratt. 1965. The life cycle of Bunoderella metteri (Allocreadiidae: Bunoderinae), a trematode parasite of Ascaphus truei. Journal of Parasitology 51(4): 579-582.
- Schmidt, K.P. 1953. A checklist of North American Amphibians and Reptiles. Sixth edition. American Society of Icthyologists and Herpetologists. 280 p.
- Schmidt, P.S. 1970. Auditory receptors of two mating call-less anurans. Copeia 1970: 169-170.
- Simons, L.H. and M. Simons. 1998. Ascaphus truei (tailed frog). Herpetological Review 29(2):106.
- Slater, J.R. 1931. The mating behavior of Ascaphus truei Stejneger. Copeia 1931(2): 62-63.
- Slipp, J.W. and G.C. Carl. 1943. Northward extensions of the range of Ascaphus. Copeia 1943(2): 127.
- Smith, H.M. 1932. Ascaphus truei Stejneger in Montana. Copeia 1932(2): 100.
- Smith, S.N. 1997. Ascaphus truei (tailed frog). Herpetological Review 28(1):47.
- Stebbins, R. C. 2003. A field guide to western reptiles and amphibians. 3rd Edition. Houghton Mifflin Company, Boston and New York. 533 p.
- Stejneger, L.H. 1899. Description of a new genus and species of discoglossoid toad from North America. Proceedings of the U.S. National Museum. Volume 21, p.899-901, pl. 89, figs. 1-4.
- Stephenson, N.G. 1951. Observations on the development of the amphicoelous frogs, Leiopelma and Ascaphus. Journal of the Linnaean Society 14: 18-28.
- Stoddard, M.A. and J.P. Hayes. 2005. The influence of forest management on headwater stream amphibians at multiple spatial scales. Ecological Applications 15(3): 811-823.
- Storm, G.L., G.J. Fosmire, and E.D. Bellis. 1994. Persistence of metals in soil and selected vertebrates in the vicinity of the Palmerton Zinc Smelters. Journal of Environmental Quality 23(3): 508-514.
- Thompson, Richard W., Western Resource Dev. Corp., Boulder, CO., 1996, Wildlife baseline report for the Montana [Montanore] Project, Lincoln and Sanders counties, Montana. In Application for a Hard Rock Operating Permit and Proposed Plan of Operation, Montanore Project, Lincoln and Sanders Counties, Montana. Vol. 5. Stroiazzo, John. Noranda Minerals Corp., Libby, MT. Revised September 1996.
- Timken, R. No Date. Amphibians and reptiles of the Beaverhead National Forest. Western Montana College, Dillon, MT. 16 p.
- Van Denburgh, J. 1912. Notes on Ascaphus, the discoglossoid toad of North America. Proceedings of the California Academy of Sciences (4) 3: 259-264.
- Van Dijk, D.E. 1955. The "tail" of Ascaphus. Ann. University Stellenbosch 31: 1-71.
- Van Eeden, J.A. 1951. The development of the condo-cranium of Ascaphus truei Stejnegar. Acta Zoologica 32: 41-176.
- Villiers, 1934a. On the morphology of the epipubis, the Nobelian bones and the phallic organ of Ascaphus truei Stejneger. Anatomischer Anzeiger 98: 23-47.
- Villiers, 1934b. Studies on the cranial anatomy of Ascaphus truei Stejneger the American "liopelmid". Bulletin Museum of Comparative Zoology Harvard 77: 1-38.
- Visalli, D. and W.P. Leonard. 1994. Ascaphus truei (tailed frog). Herpetological Review 25(1): 31
- Wahbe, T.R. 1996. Tailed frogs (Ascaphus truei, Stejneger) in natural and managed coastal temperate rainforests of southwestern British Columbia, Canada. M.S. Thesis, University of British Columbia, Vancouver, British Columbia.
- Wahbe, T.R. and F.L. Bunnell. 2001. Preliminary observations on movements of tailed frog tadpoles (Ascaphus truei) in streams through harvested and natural forests. Northwest Science 75(1): 77-83.
- Wahbe, T.R., C. Ritland, F.L. Bunnell, and K. Ritland. 2005. Population genetic structure of tailed frogs (Ascaphus truei) in clearcut and old-growth stream habitat in south coastal British Columbia. Canadian Journal of Zoology 83:1460-1468.
- Wahbe, T.R., F.L. Bunnell, and B. Bury. 2001. Philopatry and movements of tailed frogs in coastal British Columbia. Northwestern Naturalist 82(2):83.
- Wahbe, T.R., F.L. Bunnell, and R.B. Bury. 2004. Terrestrial movements of juvenile and adult tailed frogs in relation to timber harvest in coastal British Columbia. Canadian Journal of Forest Research 34:2455-2466.
- Wallace, R.L., and L.V. Diller. 1998. Length of the larval cycle of Ascaphus truei in coastal streams of the redwood region, northern California. Journal of Herpetology 32: 404-409.
- Welsh, H.H. Jr. and L.M. Ollivier. 1998. Stream amphibians as indicators of ecosystem stress: a case study from California's redwoods. Ecological Applications 8(4): 1118-1132.
- Welsh, H.H., Jr. 1985. Geographic distribution. Ascaphus truei (tailed frog). Herpetological Review 16(2): 59.
- Welsh, H.H., Jr. and R.J. Reynolds. 1986a. Ascaphus truei (Tailed Frog). Behavior. Herpetological Review 17(1):19.
- Welsh, H.H., Jr. and R.J. Reynolds. 1986b. Life history notes. Anura. Ascaphus truei (tailed frog). Herpetological Review 17(1): 19.
- Werner, J.K. and J.D. Reichel. 1996. Amphibian and reptile monitoring/survey of the Kootenai National Forest: 1995. Montana Natural Heritage Program. Helena, MT. 115 pp.
- Werner, J.K. and J.D. Reichel. 1994. Amphibian and reptile survey of the Kootenai National Forest: 1994. Montana Natural Heritage Program. Helena, MT. 104 p.
- Werner, J.K. and T. Plummer. 1995a. Amphibian and reptile survey of the Flathead Indian Reservation 1993-1994. Salish Kootenai College, Pablo, MT. 55 pp.
- Werner, J.K. and T. Plummer. 1995b. Amphibian monitoring program on the Flathead Indian Reservation 1995. Salish Kootenai College, Pablo, MT. 46 p.
- Werner, J.K., B.A. Maxell, P. Hendricks and D.L. Flath. 2004. Amphibians and Reptiles of Montana. Mountain Press Publishing Company: Missoula, MT. 262 pp.
- Werner, J.K., T. Plummer, and J. Weaselhead. 1998b. The status of amphibians on the Flathead Reservation, Montana. Intermountain Journal of Sciences 4(3-4): 88.
- Werner, J.K., T. Plummer, and J. Weaslehead. 1998a. Amphibians and reptiles of the Flathead Indian Reservation. Intermountain Journal of Sciences 4(1-2): 33-49.
- Wernz, J.G. 1969. Spring mating of Ascaphus. Journal of Herpetology 3: 167-169.
- Wernz, J.G. and R.M. Storm. 1969. Pre-hatching stages of the tailed frog (Ascaphus truei Stejneger). Herpetologica 25: 86-93.
- Wickbom, T. 1950. The chromosomes of Ascaphus truei and the evolution of the annuran karyotypes. Hereditas 36: 406-418.
- Wilson, A.G. and E.M. Simon. 1988. Supplementary report on the status of the Coeur d' Alene salamander (Plethodon idahoensis) in Montana. Report to the Montana Natural Heritage Program, Helena.
- Additional Sources of Information Related to "Amphibians"