formerly Bufo hemiophrys
Canadian Toad / Crapaud du Canada
This relatively small toad is either brown to grey-green or reddish with reddish
warts surrounded by black spots. There is a light line down the centre of the back
and the belly is pale with grey spots. It is distinguished by
cranial crests which fuse
to form a hump, or "boss" between the eyes. The
parotoid glands are large
and oval or kidney shaped and meet the cranial crests. Two prominent
tubercles on its hind feet
are used for burrowing. Maximum adult size is only 7 cm.
call of the Canadian Toad is a brief harsh trill shorter than that of the
Eastern American Toad but longer than that of
the Gray Treefrog. It is repeated
every 15-20 seconds. Males may call at temperatures as low as 5oC.
The Canadian Toad overlaps with the American
Toad in central Manitoba, the Great Plains
Toad on the extreme southern prairie provinces and the
Boreal Toad in Alberta. It can be distinguished
from these species based on the presence and shape of the cranial crests and parotoid
glands. The Eastern American Toad has elongate parotoid glands which do not touch the cranial
crest. The Great Plains Toad has cranial crests which diverge between the eyes.
The Boreal Toad has no cranial crests. Spadefoots also have digging tubercles on
their hindfeet, but unlike toads they have neither cranial crests nor parotoid glands.
The Canadian Toad is widely distributed through the eastern half of Alberta, most of
Saskatchewan and the western half of Manitoba.It reaches its northern extent in the
Northwest Territories near Fort Smith. In the United States it is restricted to
Montana, the Dakotas and Minnesota, with a disjunct population in Wyoming. This
is one of the few amphibians with most of its range in Canada.
Canadian Toads are found near ponds, lakes and potholes throughout the prairies
and aspen parkland and more sparsely in boreal forests. Breeding occurs in the
shallow margins of permanent water or in temporary ponds and puddles.
Breeding occurs from May to July. Up to 7000 eggs are laid in a single strand and
hatch three to twelve days later. Juvenile toads emerge six to seven weeks later.
The Canadian Toad may be active during the day or night depending on temperatures.
It burrows underground to avoid extreme heat and also hibernates below the frost
line. Worms, beetles and ants are among the foods eaten. Although highly terrestrial
it will take to water to avoid capture.
The Canadian Toad has declined in southern Alberta and parts of Manitoba. Possible
threats include wetland drainage and drought.