Description
Also called the Wandering Garter Snake, this long
slender species can reach just over a metre in total length. It is
quite variable in colour but usually has a distinct pale yellow or
brown stripe down the back. The side stripes are the same colour
as the back stripe and occupy the second and third scale rows. The
background colour is brown, grey or green with darker spots between
the stripes. The Western Terrestrial Garter Snake is distinguished
from other Garter Snakes by the eight scales on its upper lip, two
of which are enlarged.
Confusing Species
Similar snakes found on the prairies are the Common Garter Snake and the Prairie Garter Snake. The Prairie Garter
Snake has its side stripes on the third and fourth scale rows and
these are paler than the back stripe. Although the Common Garter
Snake also has its side stripes on the second and third scale rows
it differs from the Western Terrestrial Garter in having only seven
scales on the upper lip. The subspecies of Common Garter Snake
found on the prairies is the Red-sided Garter which has red or
orange bars between the back and side stripes.
Similar species found in British Columbia include the Northwestern Garter Snake and the Common Garter Snake. Both species have only
seven scales on the upper lip. The Northwestern Garter Snake has
a more distinct brightly coloured back stripe. The subspecies of
Common Garters found in British Columbia either have red or black
on the top of the head.
Distribution
The Western Terrestrial Garter Snake is widely
distributed in southern British Columbia, Alberta and southwestern
Saskatchewan. Its range extends south to New Mexico.
Habitat
This species is often found near streams, lakes, ponds
and marshes but may also be found some distance from water.
Reproduction
Like other Garter Snakes this species bears live young
rather than eggs. From 4-19 young may be born in a litter in mid
to late summer.
Natural history
The Western Terrestrial Garter Snake eats a wide
variety of invertebrate and vertebrate prey captured both in the
water and on land. Large numbers may hibernate together in mammal
burrows or natural crevices and be found together on emergence in
the spring. It is sometimes seen basking in the morning and will
take to water when disturbed.
Conservation Concerns
This species is considered secure in Canada.
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