With another long, cold winter looming, it’s time for the city’s snake population to head for cover.
Garter snakes are a common sight in Fort Saskatchewan in the warmer months, particularly in springtime in the city’s river valley, when they emerge in large numbers ready to start new families.
Right now, the snakes are searching for somewhere warm to sleep before daytime highs drop below freezing. The scaly reptiles need to find shelter underground, below the frost line, to survive the frigid Alberta winter.
According to Kris Kendell, a biologist with the Alberta Conservation Association, garter snakes aren’t good burrowers—the reptiles make do with what they can find, hunkering down in holes dug by small mammals or in cracks and crevices caused by erosion.
“Also there is going to be a little bit of moisture underground so it helps to protect them from becoming dehydrated during the wintertime," he said.
The Edmonton area, including Fort Saskatchewan, is home to two species of garter snake, both often spotted slithering through river valleys and other less developed places in the urban environment. Plains garter snakes prefer the open spaces of grassland areas while their more colorfully named relative, the red-sided garter snake, is more common north and west of Edmonton.
During the winter, the two species of snake may find themselves roommates. With limited accommodations available on the landscape, snakes may all end up at the same underground hangout after journeying—sometimes many kilometres—from their summer habitats.
“Oftentimes a lot of garter snakes, a lot of snake species in general, will arrive at these locations in rather large numbers and all overwinter together in what we call a communal den. And these dens can have just one species of snake in them or multiple species of snakes, ” Kendell said. “So they often will collect snakes from quite a broad area."
That dark, earthy den of snakes is called a hibernaculum—or hibernacula, when there’s more than one.
Garter snakes don’t wake up for snacktime once they’re hibernating. Before winter hits they build their fat and energy stores by eating young mice, leeches, tadpoles, baby tiger salamanders and other small, nutritious creatures. Wetlands, Kendell said, are a rich hunting ground for garter snakes.
The annual migration to winter den locations means a few garter snakes are still likely to be out and about, potentially crossing local roadways or trail systems in parks.
“Unfortunately sometimes they can be run over by vehicles or even bicycles,” Kendell added.
Kendell advises resisting any temptation to get too close to the snakes at any time of year.
“If you encounter a garter snake in the wild, it's really nice to be able to just admire it and marvel at it,” he said, adding that handling by humans can put the snakes at risk of being dropped and injured or contaminated with chemicals, such as sunscreen or bug spray, that might be on human hands.
“Just let them be their little snakey selves and let them go about their business."