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.

Citation: IUCN SSC Amphibian Specialist Group. 2015. Ascaphus montanus. The IUCN Red List of Threatened Species 2015: e.T54413A56953461. . Downloaded on 30 November 2015.
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