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Five Wild Facts About Oh-So-Common Garter Snakes

Updated: Mar 8, 2023

Garter snakes are a snake most people are familiar with because of how common they are across most of the United States. If you see a dark-colored snake with stripes, it is probably a garter snake.

A garter snake. (Photo via Shutterstock)

Most of the garter snakes we see here are common garter snakes, but about a dozen subspecies of the common garter snake have been recognized. Two of these subspecies live in Illinois: the eastern garter snake and the Chicago garter snake. Illinois is also home to another garter snake species, the plains garter snake.


Snakes are an important part of the ecosystem, so seeing them around your home or neighborhood is a good thing. They aren't venomous (no snakes in Will County are), but they will sometimes bite to defend themselves.


Read on to learn more about garter snakes.


They are named for their stripes

(Photo by Anthony Schalk)

These snakes are called garter snakes, not garden snakes, gardener snakes or even gartner snakes as they are sometimes mistakenly called. They are called garter snakes because of the three stripes on their backs. These stripes are said to look like the garters that men used to use to hold up their socks. Most often these stripes are yellow, but they can also be white, brown, green or blue.


The scientific name for the common garter snake is Thamnophis sirtalis. The term Thamnophis is Greek. Thamnos means bush, and ophio means snake. The term sirtalis is Latin, and it is a reference to the stripes on their backs. Different garter snake species have different scientific names, but all share the Thamnophis name. For example, the scientific name of the plains garter snake is Thamnophis radix, and the eastern garter snake is Thamnophis sirtalis sirtalis. The addition of a third term indicates it is a subspecies.


They are the most widespread snake in the United States


No snake is more widespread across the United States than the common garter snake. You can find these snakes across the entire eastern United States, including all of Illinois, as well as most of the West Coast and Pacific Northwest and parts of Canada. One reason they are so common and widespread is that they are very adaptable and can survive in extreme temperatures.

 

Words to know

Adaptable: Able to adjust to new conditions.

Brumation: The form of hibernation for cold-blooded, or ectothermic, animals.

Ecosystem: A biological community of interacting organisms and their physical environment.

Encounter: An unexpected experience with someone or something.

Immobilize: To prevent something from moving as normal.

Keen: Highly developed.

Pheromones: A chemical substance released by an animal to affect the behavior of other animals of its species.

Redistribute: To spread something out differently or again.

Venomous: Capable of secreting a poisonous substance.

Widespread: Found or distributed over a large area or number of individuals.

 

Garter snakes are usually found near water and prefer grassy, moist habitat areas. They are common in woodlands and meadows and along the edges of waterways. They are often encountered by humans because they do well in urban and suburban areas. Flip over a log, rock or board in your yard or neighborhood and don't be surprised to see a garter snake slither away.


They can have a whole lot of babies

A garter snake and its babies. (Photo via Shutterstock)

Dozens and dozens of baby garter snakes slithering around may be a nightmare for some people, but garter snakes can have as many as 80 babies at once! Most typically, though, females will have between 10 and 40 babies per litter. Garter snakes mate in the spring, as soon as they emerge from brumation, which is similar to hibernation. Male snakes emit pheromones to attract females. After mating, the female snakes go to their summer habitat area to find a place to give birth.


Common garter snakes are ovoviviparous, which means they give birth to live offspring after the eggs are incubated in the females' abdomens. Other snakes are viviparous, which means they give birth to live young without incubation, or oviparous, which means they lay eggs.


At birth, garter snakes are fully independent and able to find food on their own. They receive no care from their parents.


They are carnivores


All snakes are carnivores, although snake diets can vary greatly from species to species. For garter snakes, common foods include worms, slugs, leeches, snails, insects, small fish, crayfish, amphibians and even other snakes. They also sometimes eat small birds, small mammals and lizards. They rely on their keen senses of smell and vision to hunt for prey.

Once they snatch something to eat, they use their quick reflexes to bite into it to immobilize it. For some of their smaller prey, their saliva may be toxic enough to immobilize them, making for an easier meal. Like almost all snakes, garter snakes swallow their prey whole.


They can swim and climb

(Photo via Shutterstock)

Of course garter snakes can slither; they are snakes after all. But they can swim and climb too. So next time you see a snake swimming in the water, don't assume it's a northern water snake. Look for those telltale stripes to see if it might be a garter snake taking a dip. You might also see one slithering its way up a tree or bush, and it's nothing to be alarmed about.


It might surprise you that the act of slithering is all in the scales. The scales on snakes' underside overlap, and they create friction when in contact with the ground or another surface. The friction allows them to move forward.


Another thing that helps them slither is how they distribute their weight. When in motion, snakes’ bodies are not flat on the ground. Instead, they redistribute their weight as they move, putting more weight where their bodies can create the most friction with the ground.

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