Description
The Great Plains Toad is a moderate sized, pale brown-grey to
olive coloured toad with dark blotches and numerous small warts. It may
or may not have a stripe down the centre of the back. The parotid
glands are large and oval. The cranial crests
form an L-shaped around each eye and fuse between the eyes in a V. The
cranial crest of toadlets forms just the V. The belly is pure white. Adults
may reach 11 cm.
Call
The Great Plains Toad call is a high pitched, long mechanical
trill resembling the burst of a machine gun. A breeding chorus can be heard
for up to two kilometres across the prairies.
Confusing Species
The Great Plains Toad overlaps with the Canadian
Toad. The Canadian Toad has grey spots on the belly and the cranial
crests is a fused bump between the eyes.
Distribution
The Canadian distribution of the Great Plains Toad is limited
to extreme southeastern Alberta, southwestern Saskatchewan and southwestern
Manitoba. It is more widely distributed through the Great Plains in the
United States and down into Mexico.
Habitat
This is a grassland toad found near river flood plains, irrigation
canals, dugouts and temporary pools where it breeds. It often burrows underground,
especially to escape the heat.
Reproduction
The Great Plains Toad breeds in response to spring or summer
rains. Up to 20 000 eggs are laid in long strings in shallow, clear water.
The eggs hatch in about two days and tadpoles transform after six weeks.
Natural history
The Great Plains Toad is generally nocturnal although it is
more resistant to high temperatures than other toads. When threatened it
takes a defensive posture by puffing with air, raising on all four legs
and lowering its head. It eats moths, flies and beetles. Maturity is reached
in three to five years.
Conservation Concerns
Populations in Alberta have decline. Populations in Saskatchewan
and Manitoba are extremely small and therefore vulnerable. Possible threats
include habitat loss and drought.
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