Forest Creatures: Snakes

Of Vancouver Island's four species of snake, one is threatened and very rare

Snakes are a forest creature with an undeserved bad reputation. I thought of this when I came across a snake carcass along the Galloping Goose Trail as it passes through a mix of natural forested areas and urban development near Thetis Lake Park.

At first I thought it may be a snake skin left after a moult, but upon closer inspection, I could see that it was a near complete carcass. I wonder if the snake met its end at the hands of a fearful human unaware of the snake's harmlessness, and its importance in the forest ecosystem.

The hinged jaw can be seen in this detail

Of eighteen reptile species in British Columbia, nine are snakes. There are four kinds of snakes on Vancouver Island, and all of them are harmless.

There are 3 species of garter snakes, the Northwestern, the Western Terrestrial, and the Common garter snake, as well as the threatened Sharp-tailed snake that can be found in this area.

The only things that need to be afraid of these snakes are worms, slugs, baby birds, small rodents, tadpoles or fish - all favourite foods of snakes.

The snakes of Vancouver Island, like all snakes, eat their prey whole. They have a jaw that can dislocate to accommodate large meals, like the largest slugs in the world - Banana slugs. I have witnessed a large garter snake eating a large slug in a slow motion battle of patience vs. slime in the middle of a forest trail.

Snakes are important both as predators and prey, and keeping other species populations in balance. Eliminating snakes could cause unwanted increases in numbers of snakes' favourite prey, such as mice. They are also important because they provide food for other species such as owls, hawks, and mammals. 

Three of the four varieties of snakes in our area give birth to live young, from 2 - 85 baby snakes in a clutch.

The rare Sharp-tailed snake is found only in the southeastern part of Vancouver Island, and the southern Gulf Islands. They lay a clutch of eggs, that the young will hatch out of, in the spring.

Habitat destruction has caused an alarming drop in Sharp-tailed numbers - their undeserved bad rap doesn't help.

If you live in their range and have a hibernaculum, or underground hibernation chamber, on your property, it should be protected. You can also build a hibernaculum to encourage the recovery of this species, or attract the garters.

How To Build A Snake Hibernaculum

• Dig a hole 2 metres deep and 1.5 metres square in a warm, sunny clearing next to a woodlot. It's important that water does not accumulate at the bottom of the pit. Otherwise, it will likely freeze and kill the animals.
• Loosely fill the pit with logs and stumps, brush, and boards, mixed with leaves and soil. Or, to accommodate snakes that prefer to hibernate in rock mounds and cavities, fill with large odd-shaped rocks. There should be plenty of cavities left for the snakes to move around.
• Cover the pit with a one-metre-high mound of brush, leaves, and soil for further insulation and protection from predators: source

Snakes are important parts of the coastal forest ecosystem - enjoy viewing these amazing, colourful creatures, but do so from a distance. Although they are considered harmless, they might give you a pinch if startled or handled roughly.