Description
The Red-legged Frog is a large, true frog with clear dorsolateral
ridges. The colour varies from reddish brown to grey and there may
be some dark specks or blotches. In northern populations, these dark blotches
do not have light centres. The tympanum is indistinct
and the toes are not fully webbed. This species may be distinguished from
other frogs by the light stripe on its jaw bordering a dark mask and by
its yellow underside with red on the lower abdomen and hind legs. Adults
can reach 13 cm.
Call
The Red-legged Frog has a weak throaty call lasting two to three
seconds. Calling sometimes occurs deep under water and does not carry far.
Confusing Species
The only true frogs which naturally co-exists with the Red-
legged Frog are the Columbia Spotted Frog and the
Oregon Spotted Frog. All these species
have a light stripe on the jaw, but the Spotted Frogs may have a mask or reddish
undersides although not always. In contrast to the Red-legged Frog, the toes of the Spotted Frogs
are fully webbed and the eyes are slightly upturned. The
Wood Frog looks superficially like a Red-legged
Frog as it does have a mask and may have dark specks on it. Wood Frogs
are occasionally reddish above however their underside is white with dark
mottling.
Distribution
The Red-legged Frog has a very limited distribution in Canada,
being only found in southwestern British Columbia, Vancouver Island and
other nearby islands. This distribution continues southward along the west
coast of the United States and into Mexico.
Habitat
Red-legged Frogs are usually found in or near well vegetated
permanent water. In parts of their range they may be found at up to 2,400
m above sea level.
Reproduction
Breeding occurs in late winter or early spring. Eggs are laid
in a loose cluster on the surface of permanent water bodies. Their eggs
are more susceptible to overheating than most other frog eggs and so they
require stable water temperatures.
Natural history
The Red-legged Frog is less aquatic than the Spotted Frogs and
may be found at the shoreline or foraging on land.
Conservation Concerns
The Red-legged Frog has declined on central Vancouver Island.
Competition from introduced Bullfrogs and Green Frogs, and logging activity
may be the problem. This species has also declined throughout much of its
range in the United States. A subspecies, the California Red-legged Frog,
was recently listed as Threatened in the United States.
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