The Tailed Frog is a very unusual looking species. It has no
external eardrum (tympanum) and the male has
an external copulatory organ which appears to be a tail but is coloured
similarly to the back. The colour varies from olive, gray or tan to almost
black with dark spots on the back and a yellowish triangle on the head.
The eyes have a vertical pupil. Maximum adult size is 5 cm.
The Tailed Frog is the only Canadian frog which does not call.
Male Tailed Frogs can not be confused with any other species.
While newly transformed froglets of most species may have a remnant tadpole
tail, this true tail has a distinctly different colour and texture from
the rest of the frog and is resorbed within a few days of transformation.
The "tail" of the Tailed Frog extends from the base of the spine
and has a colour and texture similar to the skin on the back of the frog.
Spadefoots also have a vertical pupil but they have tympana as do all other
frogs and toads.
Tailed Frogs are restricted to the southwestern mainland and areas north
along the coast of British Columbia to Kitimat and Bella Coola. There are
found as far south as northern California.
Tailed Frogs inhabit cold, swift mountain streams in steep sided valleys
of forested mountain regions.
Tailed Frogs do not have a mating call. Mating occurs in spring or fall
and eggs are laid the following summer in small clusters under submerged
rocks. They remain tadpoles for two to four years and require a further
eight years to reach sexual maturity.
Adults eat aquatic and terrestrial insects. During the day they hide beneath
rocks in the stream, emerging to forage in the evening. Tadpoles attach
themselves to a rock with their mouth parts when they want to remain stationary
in the swift current and scrape algae and other food from the surface of
stones. Maximum known age is 14 years.
The Tailed Frog has declined where its habitat has been degraded by logging.
When trees are removed from adjacent to the stream, not only is foraging
habitat destroyed but the increased exposure alters the water temperature
and allows rain to wash soil into the stream. This species is considered
vulnerable in British Columbia.