Ascaphus montanus 


Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Chordata Amphibia Anura Ascaphidae

Scientific Name: Ascaphus montanus
Species Authority: Mittleman & Myers, 1949
Common Name(s):
English Rocky Mountain Tailed Frog, Inland Tailed Frog
Taxonomic Source(s): Frost, D.R. 2013. Amphibian Species of the World: an Online Reference. Version 5.6 (9 January 2013). Electronic Database. American Museum of Natural History, New York, USA. Available at:

Assessment Information [top]

Red List Category & Criteria: Least Concern ver 3.1
Year Published: 2015
Date Assessed: 2015-08-25
Assessor(s): IUCN SSC Amphibian Specialist Group
Reviewer(s): Stuart, S.N.
Contributor(s): Hammerson, G.A. & Adams, M.
Facilitator/Compiler(s): Green, C., Sharp, D. & Garcia Moreno, J.

Listed as Least Concern in view of the large extent of occurrence, large number of sub-populations and localities, and presumed large population size.

Previously published Red List assessments:
2004 Least Concern (LC)

Geographic Range [top]

Range Description: This species ranges from extreme southeastern British Columbia south through western Montana to extreme southeastern Washington, northeastern Oregon, and south-central Idaho (Leonard et al. 1993, Nielson et al. 2001, Stebbins 2003). There are many extant occurrences in Montana and Idaho and two small populations in British Columbia (L. Dupuis pers. comm. 2001).
Countries occurrence:
Canada (British Columbia); United States (Idaho, Montana, Oregon, Washington)
Range Map: Click here to open the map viewer and explore range.

Population [top]

Population: Total adult population size is unknown but is probably at least several thousand and might exceed 10,000. The species is still relatively common in Idaho and Montana. Long-term trend: probably relatively stable in extent of occurrence, unknown degree of decline in population size, area of occurrence, and number/condition of occurrences. Short-term trend: possibly declining based on habitat trends, but few population data are available.
Current Population Trend: Unknown
Additional data:
Population severely fragmented: No

Habitat and Ecology [top]

Habitat and Ecology: It lives in clear, cold swift-moving mountain streams with coarse substrate. It may occur primarily in older forest sites, but better information is needed; required microclimatic and microhabitat conditions are more common in older forests. It may be found on land during wet weather near water in humid forests or in more open habitat. During dry weather it stays on moist stream-banks. It lays eggs in long strings under stones in water. Species has a free-living larval stage.
Systems: Terrestrial; Freshwater

Use and Trade [top]

Use and Trade: There are no records of this species being utilized.

Threats [top]

Major Threat(s): Tailed frogs are sensitive to logging and road building (Leonard et al. 1993). Logging practices that increase water temperatures and siltation might have an adverse effect on tailed frog populations, which have a narrow temperature tolerance (Nussbaum et al. 1983, COSEWIC 2013). See also Bury and Corn (1988) and Corn and Bury (1989) for information on negative effects of timber harvest. Despite negative effects of logging, tailed frogs frequently occur in many young forests that have been harvested one or more times in the past. Sensitivity to timber harvest might depend on surface geology and harvest practices (Adams and Bury 2002, Welsh and Lind 2002). Diller and Wallace (1999) emphasized that current timber harvest practices are not as detrimental as those used in the past. Information on the responses of tailed frogs to timber harvest is based primarily on the coastal tailed frog, A. truei. Further information is needed on the responses of A. montanus. Apparently, low dispersal abilities might limit rate of recovery of depleted sub-populations.

Conservation Actions [top]

Conservation Actions: Conservation Actions
Occurs in Glacier National Park and several Wilderness Areas. There are many occurrences on National Forest or Bureau of Land Management lands, but these might not receive special management consideration, so protection is minimal. 

Conservation Needed
Maintenance of cool, forested, unsilted streams and stream corridors is a basic conservation need. 

Research Needed
Research is needed in population trends.

Classifications [top]

1. Forest -> 1.4. Forest - Temperate
suitability: Suitable season: resident major importance:Yes
5. Wetlands (inland) -> 5.1. Wetlands (inland) - Permanent Rivers/Streams/Creeks (includes waterfalls)
suitability: Suitable season: resident major importance:Yes
1. Land/water protection -> 1.2. Resource & habitat protection

In-Place Research, Monitoring and Planning
In-Place Land/Water Protection and Management
  Occur in at least one PA:Yes
In-Place Species Management
In-Place Education
4. Transportation & service corridors -> 4.1. Roads & railroads
♦ timing: Ongoing    
→ Stresses
  • 1. Ecosystem stresses -> 1.2. Ecosystem degradation

5. Biological resource use -> 5.3. Logging & wood harvesting -> 5.3.5. Motivation Unknown/Unrecorded
♦ timing: Ongoing    
→ Stresses
  • 1. Ecosystem stresses -> 1.2. Ecosystem degradation

1. Research -> 1.2. Population size, distribution & trends

Bibliography [top]

Adams, M.J. and Bury, R.B. 2002. The endemic headwater stream amphibians of the American Northwest: associations with environmental gradients in a large forested preserve. Global Ecology and Biogeography: 169-178.

Adams, S.B. and Frissell, C.A. 2001. Thermal habitat use and evidence of seasonal migration by Rocky Mountain tailed frogs, Ascaphus montanus, in Montana. Canadian Field-Naturalist: 251-256.

Behler, J.L. and King, F.W. 1979. The Audubon Society Field Guide to North American Reptiles and Amphibians. New York.

Blackburn, L., Nanjappa, P. and Lannoo, M.J. 2001. An Atlas of the Distribution of U.S. Amphibians. Ball State University, Muncie, IN, USA.

Bury, R.B. and Adams, M.J. 1999. Variation in age at metamorphosis across a latitudinal gradient for the tailed frog, Ascaphus truei. Herpetologica: 283-291.

Bury, R.B. and Corn, P.S. 1988. Responses of aquatic and streamside amphibians to timber harvest: a review. In: Raedaeke, K. (ed.), Streamside management: riparian wildlife and forestry interactions, pp. 165-181. Univ. Washington.

Corn, P.S. and Bury, R.B. 1989. Logging in western Oregon: responses of headwater habitats and stream amphibians. Forest Ecology and Management: 39-57.

COSEWIC. 2013. COSEWIC Assessment and Status Report on the Rocky Mountain Tailed Frog Ascaphus montanus in Canada. Committee on the Status of Endangered Wildlife in Canada, Ottawa.

Daugherty, C.H. and Sheldon, A.L. 1982. Age-determination, growth, and life history of a Montana population of the tailed frog (Ascaphus truei). Herpetologica: 461-468.

Daugherty, C.H. and Sheldon, A.L. 1982. Age-specific movement patterns of the frog Ascaphus truei. Herpetologica: 468-474.

Diller, L.V. and Wallace, R.L. 1999. Distribution and habitat of Ascaphus truei in streams in managed, young growth forests in north coastal California. Journal of Herpetology: 71-79.

Dupuis, L. 1998. Status report on the tailed frog, Ascaphus truei, in Canada (draft). Unpublished draft report submitted to the Commitee on the Status of Endangered Wildlife in Canada, Ottawa.

Dvornich, K.M., McAllister, K.R. and Aubry, K.B. 1997. Amphibians and reptiles of Washington State: Location data and predicted distributions, Vol. 2. In: Cassidy, K.M., Grue, C.E., Smith, M.R. and Dvornich, K.M. (eds), Washington State Gap Analysis - Final Report, Washington Cooperative Fish and Wildlife Research Unit, University of Washington, Seattle, Washington.

IUCN. 2015. The IUCN Red List of Threatened Species. Version 2015-4. Available at: (Accessed: 19 November 2015).

Leonard, W.P., Brown, H.A., Jones, L.L.C., McAllister, K.R. and Storm, R.M. 1993. Amphibians of Washington and Oregon. Seattle Audubon Society, Seattle, Washington.

Metter, D. and Pauken, R. 1969. An analysis of the reduction of gene flow in Ascaphus truei in the northwest U.S. since the Pleistocene. Copeia: 301-307.

Metter, D.E. 1968. Ascaphus and A. truei. Catalogue of American Amphibians and Reptiles: 1-2.

Nielson, M., Lohman, K. and Sullivan, J. 2001. Phylogeography of the tailed frog (Ascaphus truei): implications for the biogeography of the Pacific Northwest. Evolution: 147-160.

Nussbaum, R.A., Brodie, Jr., E.D. and Storm, R.M. 1983. Amphibians and Reptiles of the Pacific Northwest. University Press of Idaho, Moscow, ID, USA.

Ritland, K., Dupuis, L.A., Bunnell, F.L., Hung, W.L.Y. and Carlson, J.E. 2000. Phylogeography of the tailed frog (Ascaphus truei) in British Columbia. Canadian Journal of Zoology: 1749-1758.

Species at Risk Branch. 2002. Species at Risk Range Maps. Canadian Wildlife Service, Environment Canada. (, Ottawa.

Stebbins, R.C. 1985. A Field Guide to Western Reptiles and Amphibians. Second Edition. Houghton Mifflin Company, Boston, Massachusetts.

Stebbins, R.C. 2003. A Field Guide to Western Reptiles and Amphibians, Third Edition. Houghton Mifflin Company, Boston, Massachusetts.

Thomas, J.W., Ward, J., Raphael, M.G., Anthony, R.G., Forsman, E.D., Gunderson, A.G., Holthausen, R.S., Marcot, B.G., Reeves, G.H., Sedell, J.R. and Solis, D.M. 1993. Viability assessments and management considerations for species associated with late-successional and old-growth forests of the Pacific Northwest. The report of the Scientific Analysis Team. USDA Forest Service, Spotted Owl EIS Team, pp. 530 pp. Portland, Oregon.

Wallace, R.L. and Diller, L.V. 1998. Length of the larval cycle of Ascaphus truei in coastal streams of the redwood region, northern California. Journal of Herpetology: 404-409.

Welsh, H.H., Jr. 1990. Relictual amphibians and old-growth forests. Conservation Biology: 309-319.

Welsh, H.H., Jr. and Lind, A.J. 2002. Multiscale habitat relationships of stream amphibians in the Klamath-Siskiyou region of California and Oregon. Journal of Wildlife Management: 581-602.

Citation: IUCN SSC Amphibian Specialist Group. 2015. Ascaphus montanus. The IUCN Red List of Threatened Species 2015: e.T54413A56953461. . Downloaded on 26 November 2015.
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