The amazing but common snake of Ontario

On our way to Restoule Provincial Park, Anna said “I think that was a snake on the road.”

“Let’s go back and check it then,” I responded.

“It looks like a gartersnake,” she said as we got closer.

We stopped anyway.  We wanted to be sure it wasn’t one of it’s rarer cousins.

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There are 17 snake species in Ontario.  Many of them are rare, but the Eastern Gartersnake (Thamnophis sirtalis sirtalis) is the most widely distributed snake in North America.  Because of its large distribution, sometimes it’s easy to think “It’s just a gartersnake.”  But we should not forget how amazing these reptiles are!

Holding the Eastern Garter snake this way causes less stress/injury.

Amazing Fact #1: Eastern Gartersnakes push the limits.

Snakes don’t produce their own body heat.  They depend mostly on the sun and environment to obtain the heat they need to survive.  It is not surprising that only a few species are able to live in northern climates.  The Eastern Gartersnake pushes the limits of cold-tolerance in snakes.  It occurs as far north as the Albany River!

Reproduced with permission from Ontario Nature, 2014

Amazing Fact #2: Eastern Gartersnakes come in many colours.

The Eastern Gartersnake is a medium-sized snake; typically 40 to 90 cm at maturity.  The typical colour pattern is a greenish or brownish gray with yellow stripes.  Often the back has a checkered pattern.  But what if you saw a snake without these characteristics, could it be a garter?  It sure can!  Eastern Gartersnake comes in a range of colours and patterns, including blue or even bright red.  There is a ‘melanistic’ colouring caused by a recessive genetic trait that makes the snake mainly black!  This usually occurs in colder northern climates.  Dark colours are perfect for soaking up that sun to maintain body temperature.

Middle photo credit: Donnell Gasbarrini, 2014

Amazing Fact #3: Eastern Gartersnakes hibernate in groups.

Most snake species live largely solitary lives.  However, Eastern Gartersnakes group together when they hibernate, mate, and just before giving birth.  When it is time to hibernate for the winter, gartersnakes will find a communal den, such as burrows and deep rock crevices.  There could be hundreds of snakes in this one area!

Amazing Fact #4:  How Gartersnakes Hunt and Eat

Snakes are known for swallowing their prey live, gartersnakes are no exception.  Once swallowed the prey will suffocate or come victim to the digestive secretions.  A gartersnake’s saliva is also mildly venomous, which gets put into the prey from the snake’s teeth.  What is truly amazing is how gartersnakes find their food through olfaction, meaning they smell with their tongues!  They are equipped with a chemical sensory organ on the roofs of their mouths, called the Jacobson’s gland.  When the snake puts its tongue into the air, the tips of the tongue load up on all the scent molecules. The tips of the tongue then get entered into the gland, which are tiny pits on the roof of the snake’s mouth.  Once the prey is located, the snake uses both vision and olfaction.

Amazing Fact #5:  Gartersnakes Give Birth to Live Young

Many of Ontario’s snakes do not lay eggs, but carry the developing young within their body.  Gartersnakes mate in the spring, soon after hibernation.  The females will carry the young until fall and give birth to about 10-30 young, depending on the snake’s age and size.  Females usually deliver in August or September.  Just before delivery the females may group together in secluded places, away from hibernation sites.  Gartersnakes do not provide maternal care after delivery.  However, the young snakes have a tendency to stay together.

Snakes and Roadways

These are just a few of the many facts about Eastern Gartersnakes that make them amazing reptiles. Unfortunately, many gartersnakes die on roadways.  To them, the hot pavement seems like a perfect place for these reptiles to soak up the sun.

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“Oh no, she was carrying babies!” Anna exclaimed.

We discovered the snake was a female garter, her head and front section had been crushed by a passing vehicle.  Around her we found a few of her babies:  one dead, one certainly injured.  But where some would have only noticed a tragedy, we spotted opportunities too.  We carefully manipulated her body, and an uninjured snake emerged from her wound.  This lead to more manipulation, and later some roadside “surgery.”  In total we estimate that we recovered 8 baby snakes.

Within a few minutes, most were alert and ready to move.  That’s another cool thing about snakes.  Once young snakes emerge from an egg or their mother, they are ready to take on the world.  No parental care is given, they rely on their instincts.  We took the young to a shaded area with lots of great hiding places.

Brake for Snakes

Never put yourself or others at risk on a busy road, but do try to be aware of snakes on roads and avoid hitting them if you can.  If you can stop safely, you can help a snake to cross the road in the direction it was travelling/facing.  You don’t need to pick it up.  Unless injured, snakes will move away when you approach them from behind.

Submit records of snakes, other reptiles and amphibians to the Ontario Reptile and Amphibian Atlas.  This will help us understand the current distribution of these species in Ontario, and assess their status.  It’s also a great place to learn about other snakes in of Ontario.

Share what you’ve learned with others!

Ed Morris & Anna Sheppard are ecologists with Ontario Parks in northeastern Ontario.