Tailed Frog. Ascaphus truei

Description: Adult: A small frog, with a head and body length of 35-50 mm. The body is somewhat flattened and moderately slender. The eyes are large and prominent, with a vertical pupil. No tympanum is visible. The toes of the hind feet are webbed and the fifth (outermost) toe is considerably broader than the others. The skin is covered with small tubercles. Typically olive, grey or brown, with a dark eye stripe and a pale yellow or greenish triangle on the snout. Irregular dark stripes and spots are often present on the lateral surfaces of the limbs. Belly translucent pink.

Larvae: Tadpoles with a large, round sucking mouth. Tooth rows 2-3 / 7-10. Anus median, spiracle median. Attain a total length of 30 mm. Slate grey in general colour, with a usually white or pinkish tail bordered proximally by a dark band.

Variation: Males have a tail-like intromittent organ, as well as palmar and forearm tubercles in the breeding season. At this time, additional horny black pads develop on the male's chest. Females are larger than males.

Natural history: Nocturnal. Inhabits cold, clear, clean waters, typically in forested areas. Adults eat terrestrial and aquatic insects. They remain hidden beneath rocks during the day. Adults are highly site-faithful.

Reproduction: Breeding occurs in mid-summer to fall. Reproduction is not associated with aggressive or territorial behaviour. Amplexus is pelvic. The intromittent organ of the male is used for internal fertilization, with copulation lasting from twenty-four to thirty hours. Eggs are laid in small clumps under submerged stones. Multiple clutches may be found in a single nest. They are about 4.5 mm in diameter and are unpigmented. When the tadpoles hatch they have a total length of 10-15 mm. Tadpoles hang onto rocks with their mouth and feed on algae and diatoms. They may spend two to three years as tadpoles before transforming, and up to eight years before reaching sexual maturity. Individuals may survive up to fourteen years.

Voice: None.

Distribution: Known from southwestern B.C., the northern B.C. coast near Kittimat, the area of the Fraser Valley and extreme southeastern B.C. near the Flathead River. In the United States, it occurs south from the Canadian border to the Gualala River in northern California, and is found in extreme southeastern Washington and northeastern Oregon and throughout much of northern Idaho and western Montana, north to Glacier National Park (U.S.). The Flathead River and Glacier National Park localities are within 25 km of the Alberta border. This species may exist in suitable adjacent habitats in Waterton Lakes National Park and near the Castle River.

Remarks: This species does not seem to be able to tolerate water conditions in logged areas due to higher temperatures and increased amounts of particulate matter.

Significant references: Adams 1993; Altig 1969; Altig and Brodie 1972; Bury 1968; Daugherty and Sheldon 1982a, b; De Vlaming and Bury 1970; Gaige 1920; Gradwell 1971; Green et al. 1980; Metter 1964, 1967, 1968a, b; Mittleman and Myers 1949; Noble and Putnam 1931; Ritland 1955a, b; Rodgers and Jellison 1942; Slater 1931; Van Dijk 1955.