Almost everyone can identify a “garter snake” in Ontario!
But here’s the problem:
There are multiple species and sub-species of garter snakes! Therefore, figuring out the identity of the SPECIFIC snake you are observing can be challenging. This is especially true since many of them have similar appearances and behaviors.
Today, you are going to learn about 4 garter snake species in Ontario!
- *Just a quick note – to be officially considered a garter snake, the species must be in the genus Thamnophis*
#1. Eastern Garter Snake
- Thamnophis sirtalis sirtalis
- Adults typically range from 46 to 66 centimeters in length.
- Coloration varies and can be mixtures of green, brown, or black. Look for a distinct yellow or whitish stripe down the center of their back.
- Some individuals may exhibit a checkered body pattern.
- Subspecies of the Common Garter Snake.
Eastern Garter Snakes are common and easy to locate in Ontario!
In fact, they are typically the snake species that people come across the most. They are well-adapted to living around people and can often be found in city parks, farmland, cemeteries, and suburban lawns and gardens. Though it’s not required, they prefer grassy environments near freshwater sources such as ponds, lakes, ditches, and streams.
Look for these garter snakes in Ontario basking in the sun in grassy areas near cover.
Eastern Garter Snakes will protect themselves if they are cornered or feel threatened. For example, if you capture or continually disturb one, it will defecate and release a foul-smelling musk from glands. It’s also common for them to bite as a last resort!
The Eastern Garter Snake most commonly preys on toads, frogs, slugs, salamanders, fish, and worms. However, they are very opportunistic and will eat other insects and small animals they can overpower. They’re active during both the day and night, depending on the temperature.
These garter snakes have a high birth rate (up to 50 babies!) and adapt well to human-disturbed habitats! Because of these traits, this species is not threatened and is relatively common and widespread.
#2. Red-sided Garter Snake
- Thamnophis proximus parietalis
- Normally dark green to black, but color varies.
- Three yellow stripes, one down the back and one down each side.
- As the name suggests, there are red or orange bars down their sides, located between the yellow stripes.
- Subspecies of the Common Garter Snake.
Like other garter snakes, they are habitat generalists. Look for them in Ontario everywhere, including forests, shrublands, wetlands, fields, and rocky areas. Their favorite foods include frogs, earthworms, and leeches! YUM! 🙂
In some areas, after emerging from hibernation, there are not enough females for all the males. In these cases, “mating frenzies” occur, and dozens and dozens of these snakes can be found together.
To survive colder months, Red-sided Garter Snakes have to hibernate BELOW the frost line. Depending on the area they are located in, it can be hard to find suitable locations. So the few adequate hibernation dens can shelter hundreds, even thousands, of snakes! To see an example, watch the video below:
#3. Eastern Ribbon Snake
- Thamnophis saurita
- Adults typically range from 46 to 66 centimeters in length. A slender snake with a long tail!
- Coloration is brown to nearly black with three bright yellow to cream stripes; one down the back and one down each side.
- Snout and entire head are brownish, lips and underneath head are white.
Did you see a slender garter snake in southern Ontario with a long tail?
If so, it was probably an Eastern Ribbon Snake!
This species is semi-aquatic and RARELY found far from a source of water. Look for them in a wide variety of habitats, including marshes, grassy floodplains, streams, ditches with grass, wet areas in meadows, and woodlands adjacent to wetlands. Ribbon snakes are even found in suburban areas that match these conditions.
You might spot these snakes basking on branches of trees, bushes, or grasses overhanging the water. They typically hunt in the water and prey on amphibians, fish, and invertebrates.
If disturbed, these snakes will quickly flee into grass or brushy areas. If caught, they are not aggressive and rarely bite. But you can expect them to defecate and spray musk onto your hands. In the wild, Eastern Ribbon Snakes rely on blending into their surroundings to get away from predators.
#4. Butler’s Garter Snake
- Thamnophis butleri
- Adults are slender and range from 38 to 51 centimeters in length.
- Coloration ranges from olive-brown to black with three yellow to orange stripes, one down the back and one down each side.
- Two rows of dark spots may be visible between the back and side stripes, and the head is usually small.
Butler’s Garter Snakes look almost identical to Eastern Garter Snakes in Ontario.
So how do you tell the difference?
What’s unique to Butler’s Garter Snakes is the placement of their side stripes! Technically speaking, they are centered on the third scale row up from the large, elongated scales on the underside of the body. The side stripes also overlap the adjacent second and fourth scale rows.
But unless you’re a herpetologist or want to inspect a snake closely, this probably means nothing to you. For the rest of us, their head is typically a bit small compared to other garter snakes. In addition, when they are threatened, instead of fleeing, they tend to thrash around in place.
This species is considered endangered in parts of its range. Industrial development of agricultural land has caused significant habitat loss and degradation in their range. If you want to find one, look in moist grassy habitats, typically under cover objects like rocks, logs, boards, and other debris.
Do you need additional help identifying garter snakes?
Try this field guide!
Which of these garter snakes have you seen in Ontario?
Leave a comment below!