7/14/2011

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.

7 comments:

  1. Anonymous9/7/12

    On July 7 at Cox Bay outside Tofino, BC, I came across a brownish snake approximately 24" long in the process of swallowing a slug. Of the four snake species on the island, the Sharp-tailed snake is the closest match. There was no sign of a garter snake's stripes.

    However, I see that Tofino is some way north of this species' known range on the island. Is this news?

    ReplyDelete
    Replies
    1. Tofino is outside of the range for this snake and a 24" sharp-tailed would be news. They usually come in at 30-45 cm, or a little over 12". I think their small girth, about the thickness of a pencil, might help identify them. More than likely it was a garter without stripes, which can occur.

      Their activity is reported as different than that of a garter's, more secretive. But their underside is suppose to be quite striking, not that we recommend disturbing snakes. But it is nice to be able to see them. Thanks for sharing.

      Delete
  2. Anonymous13/7/14

    My neighbor in Comox reported seeing a rather large brown snake in her yard. She estimated it's girth at approx an inch and indicated it was prob 24ish inches. She said it was not a Garter but appears too large to be a Brown. Based on comment above possibly another example of Garter w/o stripes?

    ReplyDelete
  3. Anonymous9/8/14

    Do any of the species contain harmful venom? I was just bitten by one in the Parksville area, possibly a western terrestrial about 19" in length.

    ReplyDelete
  4. Interesting to learn garter snakes do not always have stripes. I live in the Cedar area just south of Nanaimo and saw a small pure black snake in my back yard. A couple of years ago I made a pile of branches in a sunny area for snakes and whatever else and often see the normal striped garter snakes.

    ReplyDelete
  5. Anonymous18/8/15

    Dave Cutler 17 Aug 2015
    My wife and I just came back from camping at Pachena Bay campsite (Bamfield) and while we were there I happened to see a "Garter " sized snake sunning itself on one of the trails to the beach. It was completely black in colour which led me to look it up on the net. I believe what I saw was a shirttail snake. He moved quite quick when I startled him.

    ReplyDelete
  6. Anonymous22/9/15

    Found two Garter snakes just outside the city of Victoria. Both were sunning themselves on the sied of a walking path that leads into Esquimalt.

    ReplyDelete

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