Almost everyone can identify a “garter snake” in Canada!
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 10 garter snake species in Canada!
- *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 Canada!
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 Canada 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 mid to western Canada 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 eastern Canada 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. Terrestrial Garter Snake
- Thamnophis elegans
- Adults range from 46 to 104 centimeters in length.
- Most adults have three yellow, light orange, or white stripes; one down their back and two down their sides.
- Coloration is widely variable. Individuals may be brownish or greenish. Some have red and black spots between the stripes, and occasionally all black individuals are found.
This garter snake can be difficult to identify in Canada!
Even trained herpetologists have issues! Its coloration varies widely, and there are believed to be 6 subspecies, although scientists still debate this.
Terrestrial Garter Snakes occupy various habitats, including both grasslands and forests. They can even be found in mountainous areas up to 4,000 meters above sea level. As the name suggests, they’re primarily found on land. But interestingly, these garter snakes can swim well!
This species is the only garter snake in Canada with a tendency to constrict prey! Most garter snakes grab their prey quickly and just swallow, rubbing their prey against the ground if necessary.
Terrestrial Garter Snakes aren’t aggressive or dangerous, but they do possess mildly venomous saliva! It can cause a muscle infection or even kill some muscle tissue. Most bites on humans just cause pain and some swelling.
#5. Plains Garter Snake
- Thamnophis radix
- Adults average 91 centimeters in length.
- Coloration is gray-green with a distinctive orange stripe down the back and a greenish-yellow stripe down each side.
- Distinct light yellow spots on the very top of the head!
Plains Garter Snakes are almost always found in Canada in prairies and grasslands near freshwater sources. They have a fairly large population and adapt well to human-modified landscapes, and you may spot them near abandoned buildings, trash heaps, or vacant lots.
This species is considered to be one of the most cold-tolerant of all snakes! In fact, they will even come out of hibernation on warmer winter days.
The Plains Garter Snake feeds primarily on earthworms, slugs, and small amphibians. However, they have also been observed preying on small mammals and birds, including the Eastern Meadowlark and Bank Swallow.
#6. Valley Garter Snake
- Thamnophis sirtalis fitchi
- Adults range from 46 to 140 centimeters in length.
- Coloration is brown to black with three yellow stripes; one down the back and one down each side.
- Pronounced red bars between the yellow stripes. Yellowish chin, jaw, and belly, and a black head, which often has red sides.
- Subspecies of the Common Garter Snake.
Valley Garter Snakes are found in various habitats, including forests, wetlands, scrublands, fields, shorelines, and rocky areas. They’re also well adapted to humans and are often found in urban areas.
Look for these garter snakes in western Canada under rocks, logs, and other objects, which they use for cover and thermoregulation. During the winter, they hibernate, often communally below the frost line. They will use a variety of underground cavities, including mammal and crayfish burrows, rock crevices, ant mounds, as well as manmade spaces such as foundations and cisterns.
When disturbed, Valley Garter Snakes will try to escape into the water and are excellent swimmers. If captured, be prepared for them to release musk and feces onto your hands! They may also strike, but only if they feel extremely threatened.
The Valley Garter Snake is considered a species of low risk. They are quite common and adapt well to human-modified habitats. However, they are frequently killed on roadways and are sometimes killed out of fear.
#7. Puget Sound Garter Snake
- Thamnophis sirtalis pickeringii
- Adults range from 71 to 102 centimeters in length.
- Coloration is dark grey or black.
- Look for three yellow or bluish stripes; a narrow one down the back and one down each side.
This beautiful garter snake is a subspecies of the Common Garter Snake and can be found in various habitats. Look for them in forests, wetlands, shorelines, scrublands, fields, rocky areas, and urban areas. They’re typically spotted by rocks and logs, which they shelter under for thermoregulation.
As the name suggests, the Puget Sound Garter snake has a limited range. It is only found on Vancouver Island and the surrounding mainland coast in Canada and northwest Washington.
These garter snakes hibernate during the winter, often with other snakes of the same species. They’ll use a variety of underground cavities as long as they’re below the frost line. These include mammal and crayfish burrows, ant mounds, rock crevices, foundations, cisterns, and other human structures.
Puget Sound Garter Snakes hunts a wide variety of prey, primarily during the day. They’ll feed on frogs, toads, salamanders, earthworms, slugs, and small fish.
Luckily, this species adapts well to human activity, and they aren’t a high-risk species. Inside their small range, they are typically the most commonly seen snake. However, they are frequently hit on roads in urban areas, face habitat loss, and are sometimes killed out of fear.
#8. Maritime Garter Snake
- Thamnophis sirtalis pallidulus
- Adults can reach 102 centimeters in length!
- Coloration varies but is typically dark green, brown, or black. The stripes that are common on other garter snake species are missing or poorly developed.
- Features a yellowish chin, upper jaw, and belly. Some individuals may display a checkered or speckled patterning on the back.
- Subspecies of the Common Garter Snake.
Maritime Garter Snakes adapt well to humans in eastern Canada!
They are habitat generalists and can be found almost everywhere! Look for them in forests, shrublands, fields, rocky areas, wetlands, shorelines, and urban and agricultural areas. They’re commonly spotted when moving rocks or logs, where they hide underneath for protection and thermoregulation.
To survive the harsh northern winters in Canada, these garter snakes hibernate below the frost line. They’ll utilize mammal and crayfish burrows, rock crevices, underground cavities, ant mounds, and manmade structures such as foundations. Interestingly, they often hibernate communally with other snakes!
This species isn’t considered threatened and can live to be TWENTY years old! They’re relatively common and can tolerate moderately disturbed human habitats well. However, populations near roads frequently have high road mortality rates.
#9. Northwestern Garter Snake
- Thamnophis ordinoides
- Adults average between 30 and 60 centimeters in length.
- COLORATION IS HIGHLY VARIABLE. Individuals can be blackish, olive, brownish, bluish, or gray, sometimes with a reddish tint.
- Typically has three stripes, one down the back and one down each side. The color of these stripes can be red, yellow, orange, tan, white, greenish, or blue; however, on certain snakes, the stripes may be dull, narrow, or absent!
The Northwestern Garter Snake prefers damp areas in southwestern Canada with lots of vegetation and open sunny areas. They may be spotted near houses and are often found when moving boards, logs, or other objects that they use for cover.
This species is predominantly terrestrial. However, these garter snakes can swim, and some local individuals have been observed hunting in the water! They feed mainly on slugs and earthworms, but they also prey on snails, small amphibians, and possibly fish.
The Northwestern Garter Snake will typically flee into dense vegetation if disturbed. One study found that individuals with stripes usually move away quickly because their stripes make it difficult for predators to determine their speed. But plain or spotted individuals frequently freeze while fleeing because their excellent camouflage helps them blend in while they’re motionless.
#10. 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 Canada.
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 Canada?
Leave a comment below!