Distinguishing Features
This is a small delicate looking
frog, usually brown or grey in colour, but may be pinkish or even
black. Often has indistinct dark blotches, with a light bar or triangle
between the eyes and snout. The skin is rough and somewhat 'warty-looking'.
Males have a short' wide 'tail' that is used for fertilizing females.
Females have no tail. Males are 30-40 mm and females may reach 50
mm in length. (Green & Campbell, 1984. Corkran & Thoms,
1996)
Distribution
Columbia Basin: This disjunct population
is found only in the extreme southeastern part of the Columbia Basin.
British Columbia: Only four occurrences
known. Restricted to two drainages in the extreme southeast portion
of the province. (Cannings et al. 1999).
Global: The species is found from
western British Columbia south to northwest California; also western
Oregon and Washington east to Northwest Montana and Idaho. The species
is moderately widespread and locally common in the Pacific Northwest
and Rocky Mountains.
Habitat
Tailed Frogs live in cool, permanent
mountain streams with stable substrates, such as boulders and cobbles.
Stable substrate is important as debris flows and sediment loading
result in high larval mortality. There is some thought that the
required microclimatic and microhabitat conditions exist only in
older forests (Cannings et al. 1999).
Threats
Little information is known about
this population. However, in coastal populations, fewer larvae are
found in creeks with higher sediment loads and higher water temperatures.
Thus logging practices that increase siltation and water temperatures
may adversely affect Tailed Fog populations. Tailed Frogs have been
found to decline after clear-cut logging (Cannings et al. 1999).
Biology
Adult tailed frogs seek refuge during the day in
or near the stream under large cover objects. All of the life stages
have a narrow temperature tolerance, particularly the eggs. Fertilization
is internal, preventing the sperm from being washed away. Insemination
occurs in the autumn and eggs are laid under boulders in long strings
the following summer. The tadpoles attach to the underside of rocks
with wide suction-like mouths thus keeping from being swept downstream.
During this time they graze on small algae and diatoms. The larval
stage lasts about four years, with another 2-3 years before sexual
maturity is reached. Adult Tailed Frogs feed on terrestrial invertebrates
and will wander several hundred metres from the edge of the water
(Cannings et al. 1999).
