What Happens to Snakes in Winter?

What Happens to Snakes in Winter?

As the leaves continue to fall and the chilly temperatures inch ever closer, we know that winter will soon be here. While some of Ontario’s birds, bats and butterflies make their way down south to avoid the cold, snakes make their way down beneath the ground, into hibernacula (singular: hibernaculum). Groups of snakes spend their winters in these underground spaces beneath the frost line in order to escape the icy temperatures above ground. A hibernaculum can be a man-made structure, such as a building foundation, or naturally occurring, like a crevice in bedrock.

Snakes, like all reptiles, are cold-blooded (also known as ectothermic). This means they regulate their body temperature by lying in the sun to warm up, or moving into the shade to cool down. Snakes that live in cold climates like ours must seek refuge in a hibernaculum throughout the winter. Snakes can’t survive in places where the ground stays frozen year round. So if you’re deathly afraid of snakes, you might want to consider moving north of the Arctic Circle or perhaps to Antarctica.

Hognose snake

Hognose Snake (Photo by Jon Clayton)

If that’s too extreme, some islands, including Ireland, New Zealand and Hawaii don’t have a native snake population at all. Legend has it that St. Patrick exterminated Ireland’s snakes by driving them into the sea. The fossil record shows that Ireland never had a native snake population to begin with. Some people may prefer not to see these scaled critters slithering around their yards and neighbourhood parks, but contrary to popular belief, native snakes in the Credit River Watershed are harmless to humans. In fact there are no native venomous snakes in the watershed. The only venomous snake native to Ontario is the Massasauga Rattlesnake (Sistrurus catenatus). This reclusive species is classified as a species at risk within Ontario. It is now only found in four regions of Ontario, the Bruce Peninsula and the eastern side of Georgian Bay, with small, isolated populations at Wainfleet Bog in the Niagara peninsula, and Ojibway Prairie in Windsor.

Brown Snake

Brown Snake (Photo by Jon Clayton)

Snakes play an important role in our ecosystems. They are both predator and prey.  By feeding on frogs, mice and other small animals, snakes help to maintain healthy ecosystems and keep the populations of certain animals in check. Snakes are also an important source of food and energy for birds and other larger animals. Several birds of prey, like Red-shouldered Hawks, supplement with snakes to feed their young. Unfortunately, in urban areas, road mortality, habitat loss, and a lack of suitable hibernacula sites can limit snake populations.

Learn more about making your property more snake friendly by creating or enhancing snake habitat.

Learn more about amphibians and reptiles living in the Credit River Watershed.

Cover Photo: Garter Snake (Photo by Jon Clayton)

4 Comment
  • Harikumar says:

    If snakes and other animals hibernate in winder how they survive without food for long periods

    • Jon MacMull (CVC) says:

      Good question! During the colder months in Ontario, when snakes begin hibernation (also called brumation for reptiles) their metabolism slows down as their body temperature lowers with the weather, which means that the energy they need from food also decreases. Snakes will often eat more before the winter months, in order to use the stored energy to survive the winter. However unlike mammals, reptiles don’t only rely on the stored fat in their bodies for energy, but also on stored glycogen, which is a kind of sugar that can also be used as energy. Having this stored glycogen is a very handy trick for snakes, as they can save the energy from their fat stores to get a head start on mating and reproduction come spring.

      Mammals, on the other hand, do not have metabolisms which are so closely tied to their environment and external temperature. Many mammals will also try to eat more food before the winter months, in order to store the energy from their food as fat. When hibernating mammals hunker down (somewhere relatively warm and dry) over the winter, their metabolism and body temperature will also decrease, but not as much as a reptile’s will, and the excess fat which they have stored will be used as energy over the winter months to help them survive.

  • Norm says:

    Very interesting. What happens to Turkey Vultures?

    • Jon MacMull (CVC) says:

      Hi Norm. That’s a good question. Turkey vultures are a migratory bird in Ontario, so they will fly south when the temperatures get cold, and return the following spring when it gets warm again.

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