Plains Gartersnake
Plains Gartersnake
Thamnophis radix
Species at Risk: Sensitive
Description
Plains
gartersnakes are found chiefly in short grass prairie and aspen
parkland. In Alberta they range throughout the eastern half of the
province south of Cold Lake. Their most striking feature is the bold
solid orange vertebral stripe. There is a lighter yellow lateral stripe
on each side as well. While the background is described as an olive to
brown with dark spots creating a checkerboard pattern, in Western Canada
this generally blends into a largely solid black backround creating
some of the most beautifully contrasting examples of the species. The
ventral scales can be whitish, bluish green or grey. Females are larger
than males, and total lengths of adults are from 50cm to 100cm. Mating
occurs upon spring emergence from the hibernaculum. Young are born live,
in a membranous sack that is broken open during parturition or
immediately afterwards. This can be a prolific species and starting in
July females may birth 5-40 young. As many as 92 offspring have been in a
single litter. When picked up these snakes are reluctant to bite, but
quick to musk. That is, they smear onto you the contents of scent glands
and the cloacal in an attempt to deter a would-be predator from an
otherwise tasty snack.
Habitat
These
snakes are habitat generalist within their range. They live near ponds,
lakes, streams, marshes and dugouts, but will also stray a long
distance from water. These snakes are often found in urban areas as long
as enough suitable habitat persists. In addition to a water source, it
is imperative that these snakes have a place to overwinter. This may be
in naturally occurring sink holes, mammal burrows, rock piles or fishers
among tree root systems. Plains garters feed on fish, amphibians, small
mammals, worms, invertebrates and even carrion.
Conservation
The
plains gartersnake appears to be doing well in Alberta. There are many
thriving populations and they are often seen by hikers and campers on a
sunny summer day. Anecdotally gartersnakes have been decreasing in
numbers. Care must be used to keep this a common species and monitoring
programs need to be used to assess this decline. The biggest threats to
the gartersnake are the draining of wetlands and the destruction of
hibernation sites. Gartersnakes are not a protected species in Alberta
but the animals and their hibernacula are under protection during the
winter months while they are dormant. Unfortunately, this leaves an open
window for the destruction of these sites during the summer. Snake
populations without a place to spend the winter are doomed.
References
The Amphibians and Reptiles of Alberta by A.P.Russell and A.M.Bauer
Photo by Ian Kanda
