Rocky Mountain tailed frog (Ascaphus montanus)

Close up of a Rocky Mountain tailed frog.
Adult males have a ‘tail like’ organ for breeding.  (Glacier National Park)
Category: Amphibians
Family: Ascaphidae - Tailed frogs
Ecosystems: Riparian areas
State status: Candidate
Vulnerability to climate change (More details)

Moderate-
High

If you see this species, please share your observation using the WDFW wildlife reporting form. Providing detailed information such as a photo and exact coordinates will improve the confidence and value of this observation to WDFW species conservation and management.

In Washington, populations of these frogs are found only in the Blue Mountains, in the southeastern part of the state. The frog is vulnerable to management practices that alter the riparian or aquatic zones of streams.

Of greatest concern are management practices that change the moisture regime, increase sediment load, reduce woody debris input and change stream bank integrity. Protection of headwater streams is particularly important.

Description and Range

Physical description

The Rocky Mountain tailed frog is a moderately small, slender-bodied frog with rough skin. Snout to vent length is from 1.5 to 2 inches. The head is relatively large, flattened, and slightly broader than it is long. The snout is relatively short and tapers forward from the eyes. The pupil is vertical. An eye-stripe extends from the snout to the shoulder. The feet are slightly webbed, and the outer two hind toes are flattened. The dorsal (topside) color of the frog usually matches the substrate of the frog's habitat. The males have a tail-like copulatory organ, tubercles on the palm and forearm and, during the breeding season, small dark pads on the sides of the abdomen.

The tail appendage of the male is unique among anurans. Rocky Mountain tailed frogs look similar to Pacific treefrogs, but treefrogs have horizontal pupils, circular discs (“toe-pads”) at the tips of their fingers and toes, rounded (rather than flattened) 4th and 5th toes on their hind feet, and typically lighter, brighter ground coloration (often light browns and greens).

Great Basin spadefoots have vertical pupils (the only other Washington anuran that does) but they are typically found only in arid habitats and have black spades on the underside of their rear feet.

Larvae

Tailed frogs (both Coastal and Rocky Mountain taxa) have the only tadpoles in Washington able to adhere to rocks in fast-flowing streams with a large sucker-like mouth.

The Rocky Mountain tailed frog tadpole has a somewhat flattened body with dorsal eyes, a ventral suctorial oral disc (mouth) and a low fin that originates at the dorsal tail-body junction. The oral disc covers about one third of the lower body surface. The tip of the tail is broadly rounded and typically has a white spot bordered by black. The spiracle is located on mid-belly (midventral) and the nostrils are located closer to the eyes than the snout.

Eggs

The eggs are unpigmented, deposited in strings of 40 to 80 eggs and attached to the undersides of rocks in cool flowing steams.

Voice

No vocalizations have been documented. Moreover, Rocky Mountain tailed frogs lack some of the structures used to make sounds (tongue and vocal sacs) found in other frogs.

For more details about Rocky Mountain tailed frog, see the Washington Herp Atlas.  

Ecology and life history

Rocky Mountain tailed frogs are present year-round in and near perennial streams associated with cold, clear, rocky streams in mature forests. All life stages are adapted for life in fast-flowing streams. During wet weather, adults and juveniles may move into upland habitat adjacent to the stream.

A study in Idaho found tailed frogs persisted in streams that occurred in burned forest and post-burn regenerated forest showing that under certain conditions, tailed frogs can be resilient to physical stream changes resulting from natural disturbance. This included persisting in water much warmer than previously reported in the field.

These frogs are generally active at night, but tadpoles and frogs can also be observed during the day. They are most active from April to October, but this varies by site and conditions.

Mating occurs typically in fall; females retain sperm and lay eggs in early summer. Eggs hatch usually in late summer, but larvae may remain in nest site until the following summer. The larval period lasts a few years. Metamorphosis usually takes place in late summer, and metamorphs require several additional years to attain sexual maturity.

The male’s “tail” is used for internal fertilization, which prevents sperm from being washed away. Eggs are attached to the undersides of rocks to keep them in place. The tadpoles have a large sucker-like mouth that allows them to feed and move in high-energy streams without losing contact and unintentionally drifting.

Geographic range

In Washington, populations are found only in the Blue Mountains. The Washington Department of Fish and Wildlife database contains 229 observation records reported from 1997 to 2010. The occupied area is small and little is known about population size, habitat conditions or threats.

This map from the Washington Herp Atlas illustrates the known distribution of Rocky Mountain tailed frog in Washington as of 2016. 

2016 Rocky Mountain tailed salamander Washington distribution map :4 eastern counties:Walla Walla,Columbia,Garfield,Asotin
Washington Herp Atlas (2017)

For a map of range-wide distribution and conservation status of this species, check out NatureServe Explorer

Climate vulnerability

Sensitivity to climate change

Moderate-
High

Though there is limited information available regarding the sensitivity of the Rocky mountain tailed frog to climate change, particularly for Washington populations, this species may exhibit some sensitivity to predicted increases in stream temperature with climate change. Rocky mountain tailed frogs breed in streams and tadpoles spend many summers in stream habitat. However, recent data on stream temperature comparisons suggests that temperatures tolerated are considerably higher than for the Coastal tailed frog. Increases in stream temperature during the summer could lead to declines in tadpoles and adults. Both adults and juveniles may be able to avoid summer increases by migrating to areas of the stream with cooler water, and some studies have shown an ability to withstand increases in stream temperature. Additionally, potential drier, warmer conditions and increases in wildfires could alter this species’ preferred forest habitat and lead to reductions in population size. Increases in winter and spring precipitation could also lead to increased flooding events, and disturb available habitat for juveniles.

Confidence: Moderate

Exposure to climate change

Moderate-
High

  • Increased stream temperatures
  • Changes in precipitation
  • Altered fire regimes
  • Altered hydrology (i.e., increased flooding and changes in timing of high water events)
Confidence: Moderate

Regulations

Licenses and permits

Be advised that collection of this species is only permitted under a WDFW Scientific Collection Permit for research and educational activities.

Conservation

This species is identified as a Species of Greatest Conservation Need (SGCN) under the State Wildlife Action Plan (SWAP). SGCN-classified species include both those with and without legal protection status under the Federal or State Endangered Species programs, as well as game species with low populations. The WDFW SWAP is part of a nationwide effort by all 50 states and five U.S. territories to develop conservation action plans for fish, wildlife and their natural habitats—identifying opportunities for species' recovery before they are imperiled and more limited.
This species is identified as a Priority Species under WDFW's Priority Habitat and Species Program. Priority species require protective measures for their survival due to their population status, sensitivity to habitat alteration, and/or recreational, commercial, or tribal importance. The PHS program is the agency's main means of sharing fish and wildlife information with local governments, landowners, and others who use it to protect priority habitats for land use planning.

Conservation Threats and Actions Needed

  • Resource information collection needs
    • Threat: Inventory is needed in the Blue Mountains.
    • Action Needed: Continue research, surveys and monitoring to understand species distribution and status.
  • Fish and wildlife habitat loss and degradation
    • Threat: This species is closely associated with cool, forested streams. Protection of headwater streams is particularly important.
    • Action Needed: Prevent habitat modification at occupied sites.
    • Threat: Degradation of riparian areas from livestock. This species occurs on livestock rangeland; livestock impacts, well known to influence riparian systems, are currently not being paid attention to as potentially significant to this species.
    • Action Needed: Survey rangeland locations where Rocky Mountain tailed frogs are known to occur and assess habitat impacts.
  • Climate change and severe weather
    • Threat: Loss of suitable habitat. This species is closely associated with cool, forested streams, and is adapted for a life history in swift flowing water.
    • Action Needed: Minimize habitat fragmentation and maintain robust populations across landscape.

See the Climate vulnerability section for more information about threats posed by climate change to this species.

Living with wildlife

Frogs, along with salamanders and newts, are members of the animal group called amphibians. Frogs start their lives as totally aquatic larvae with gills and a pronounced tail fin; this is familiar to many people as the tadpole stage. Over time, legs develop, the tail and gills are absorbed, and the frog transforms into a terrestrial, air-breathing animal.

Learn more about living with frogs, including how to attract them or prevent conflicts.

Resources

References

Bull, E. L., and B. E. Carter. 1996. Tailed frogs: distribution, ecology, and associations with timber harvest in northeastern Oregon. Pacific Northwest Research Station, US Forest Service, Department of Agriculture, Portland, OR. 11 pp.

Corn, P. S. and R. B. Bury. 1989. Logging in western Oregon: responses of headwater habitats and stream amphibians. Forest Ecology and Management 29:39–57.

Dunham, J. B., A. E. Rosenberger, C. H. Luce, and B. E. Rieman. 2007. Influences of wildfire and channel reorganization on spatial and temporal variation in stream temperature and the distribution of fish and amphibians. Ecosystems 10(2):335-346

McDiarmid, R. W. and R. Altig (editors). 1999. Tadpoles: The Biology of Anuran Larvae. University of Chicago Press. xvi + 444 pp.,

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.

Nussbaum, R. A., E. D. Brodie, Jr., and R.M. Storm. 1983. Amphibians and Reptiles of the Pacific Northwest. University of Idaho Press, Moscow, Idaho. 332 pp.

Stebbins, R. C. 1985. A Field Guide to Western Reptiles and Amphibians, 2nd Edition. The Peterson Field Guide Series. Houghton Mifflin Company, Boston. 336 pp.

Welsh, H. H. Jr. and A. J. Lind. 1996. Habitat Correlates of the Southern Torrent Salamander, Rhyacotriton variegatus (Caudata: Rhyacotritonidae), in Northwestern California. Journal of Herpetology 30(3): 385-398.

Zug, G. R.; Vitt, L. J. & Caldwell, J. P. (2001). Herpetology, 2nd ed. Academic Press San Diego, London, 630 pp.

WDFW. 2014. WDFW Wildlife Survey and Management Database.

Personal communications

Marc Hayes, Washington Department of Fish and Wildlife, Olympia, Washington.

WDFW publications 

PHS Program

WDFW educational resources

Other resources