Rocky Mountain Tailed Frog
Scientific Name: Ascaphus montanus
Other/Previous Names: Tailed Frog (Southern Mountain population)
Taxonomy Group: Amphibians
Range: British Columbia
Last COSEWIC Assessment: November 2013
Last COSEWIC Designation: Threatened
SARA Status: Schedule 1, Endangered
Image of Rocky Mountain Tailed Frog
Both adult Rocky Mountain Tailed Frogs and their tadpoles have unique morphological adaptations to life in fast-flowing mountain streams. The adults can vary in colour from tan or brown to olive green or red, and pale coloured individuals have indistinct dark blotches. There is often a distinct copper-coloured bar or triangle between the eyes and snout. This generally has green undertones. The frogs are small (2.2 to 5.1 cm long) with a large head, a vertical pupil, broad and flattened outer hind toes, and no tympanum (external eardrum). Males have a short, conical "tail" used during mating. The tadpoles are black or brownish-grey and may have lighter flecks. They have a flattened body and a laterally compressed tail bordered by a dorsal fin. They usually have a white dot at the tip of the tail, and possess a disc on the mouth that has become modified into an adhesive sucker for clinging to rocks in swift currents. Rocky Mountain Tailed Frogs and their tadpoles have distinct, dense, fine, black speckling on the dorsal and ventral surfaces.
Distribution and Population
The Rocky Mountain Tailed Frog occurs in the interior mountains of British Columbia, Montana, and Idaho. In Canada, the frog has a very small and restricted range in the Kootenays of extreme southern British Columbia. This population consists of two sub-populations isolated from one another by the dry Rocky Mountain Trench, and also isolated from the US populations. The frogs are known from only seven sites. No population estimates exist but populations are low and probably declining. Only a small percentage of creeks within its range are suitable for breeding, but the frogs are absent from many of them and tadpole densities are very low.
The Rocky Mountain Tailed Frog needs small, cold, clear, mountain streams with forested borders, a bed of boulders or cobbles, a 4% gradient and must remain ice-free in winter. The species is limited to wet forests on steep slopes, high elevations, and talus -- conditions which enhance the availability of cool, moist microhabitats. The creeks must remain cool throughout the summer as the species has a narrow temperature tolerance. The eggs require temperatures of 5 to 18.5 C to survive. Adults cannot tolerate temperatures much above 20 C, but have been found in streams with temperatures of up to 16 C. Adults and tadpoles do not burrow into the substrate but winter under rocks or at the stream surface. About 75% of the Rocky Mountain Tailed Frog's habitat has been at least partially developed and old-growth forests that are critical to the species continue to decline.
The primitive, long-lived Rocky Mountain Tailed Frogs breed in cold mountain streams. Courtship takes place in the water in early fall. The sperm stays viable in the female's oviducts until egg-laying in June or early July. Each female produces a double-strand of 50 to 85 colourless, pea-size eggs which she attaches to the underside of a large rock or bolder in the stream. The species has the largest eggs and the longest embryonic period (time it takes the eggs to hatch) of all North American frogs. It has a very low reproductive rate, and females lay eggs every other year. Hatchlings remain in the natal pool until their suctorial mouth is fully developed, after which they become more mobile. The tadpole stage lasts up to five years. Tadpoles are relatively sedentary but may disperse or drift downstream. Although newly metamorphosed froglets move only short distances along a stream, older juveniles (4 to 7 years) disperse over considerable distances and represent the life stage that undergoes the greatest movements. They reach sexual maturity at six to eight years of age. In the Kootenays, Rocky Mountain Tailed Frogs tend to be nocturnal because that is when the ambient temperature and humidity levels are suitable. Adults are extremely closely associated with their breeding creek throughout their lives, many of them not moving more than 20 m per year and between years. They generally remain within a short distance of stream banks. They have small home ranges. The species is one of the least tolerant among frogs to drying out. Tadpoles feed on diatoms which they scrape from submerged rocks with their numerous, small, black, circular teeth. Adults and juveniles eat a variety of items, but feed primarily on spiders and other terrestrial arthropods such as ticks, mites, collembolans (snow fleas) and various insects as well as snails. They also feed on aquatic species, but to a lesser extent. They are preyed upon by American dippers, garter snakes, trout, western toads, and Coastal Giant Salamanders.
Tadpoles of the Rocky Mountain Tailed Frog are vulnerable to local extirpations or population declines from massive bedload (boulders, logs, and debris) movements in the creeks, compounded by logging practices that increase the amount of sediment in the stream beds. This sediment fills the spaces between larger rocks, eliminating refuge sites used to escape floods, massive bedload movements, predation, and warm temperatures. Large-scale habitat disturbance, loss, and fragmentation through road building and clear-cut logging are detrimental to the species. The population is geographically isolated, occurs in low densities at very few sites, and the breeding habitats are particularly vulnerable to disturbance, especially logging and road building. This population has low tadpole densities and is limited by its specialized habitat requirements, restricted amount of available habitat, scarcity of stable breeding creeks, sensitivity to logging, low tolerance for warm temperatures, and potentially limited dispersal capabilities.
Federal ProtectionThe Rocky Mountain Tailed Frog is protected under the federal Species at Risk Act (SARA). More information about SARA, including how it protects individual species, is available in the Species at Risk Act: A Guide.
The Rocky Mountain Tailed Frog is protected by the British Columbia Wildlife Act. Under this Act, it is prohibited to kill, collect, or hold captive any amphibian without a permit.
Provincial and Territorial Protection
Status of Recovery Planning
Recovery Strategies :
Name Recovery Strategy for the Rocky Mountain Tailed Frog (Ascaphus montanus) in Canada
Status Final posting on SAR registry
Rocky Mountain Tailed Frog Recovery Team
Ted Antifeau - Chair/Contact - Government of BC
Phone: 250-354-6163 Fax: 250-354-6332 Send Email
Recovery Progress and Activities
Summary of Progress to Date A recovery team has been established to coordinate recovery actions for the Rocky Mountain Tailed Frog and develop a recovery strategy. Summary of Research/Monitoring Activities Surveys indicate that there are two geographically separated populations of Rocky Mountain Tailed Frog in B.C.- one in the Flathead river watershed and one in the Yahk river watershed. Intensive inventories have been conducted for both populations to define their range and their distribution within the range. Population monitoring protocols are being developed to monitor both populations and the condition of their habitat. Summary of Recovery Activities A small portion of Rocky Mountain Tailed Frog habitat in the Flathead watershed was significantly affected by wildfires in 2003. Access roads built for fire-fighting have been deactivated or stabilized in order to mimimize pollution of tailed frog streams with sediment. The effectiveness of these rehabilitation measures will be ongoing through 2005 and possibly beyond, and the recovery team may recommend further rehabilitation measures. Currently, the recovery team is developing a watershed level riparian habitat protection plan for both the Yakh and Flathead watersheds. Almost all of the frog’s habitat occurs on Crown land. Therefore, the recovery team aims to create Wildlife Habitat Areas to protect critical breeding and dispersal sites throughout these watersheds. Stream and stream-side habitat in Wildlife Habitat Areas will be protected by restricting livestock access, harvesting and mining activity.
PLEASE NOTE: Not all COSEWIC reports are currently available on the SARA Public Registry. Most of the reports not yet available are status reports for species assessed by COSEWIC prior to May 2002. Other COSEWIC reports not yet available may include those species assessed as Extinct, Data Deficient or Not at Risk. In the meantime, they are available on request from the COSEWIC Secretariat.
6 record(s) found.
- COSEWIC Status Reports (1 record(s) found.)
- Response Statements (1 record(s) found.)
- Recovery Strategies (1 record(s) found.)
- COSEWIC Annual Reports (1 record(s) found.)
- Consultation Documents (1 record(s) found.)
- Recovery Document Posting Plans (1 record(s) found.)
COSEWIC Status Reports
COSEWIC Annual Reports
Recovery Document Posting Plans
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