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Fast Facts: Common garter snake

Scientific name: Thamnophis sirtalis
Average weight: 150 g
Average length: 46 to 137 cm
Average lifespan: 2 years in the wild and 6 to 10 years in captivity

Did you know?

Female common garter snakes can have as many as 70 to 80 young in a single litter!


Common garter snakes can differ in appearance from region to region. Generally, they have three stripes on their backs, one down the center and one on either side of it. These stripes run the length of the snake’s body and can be blue, green, yellow or white. Some snakes have an extremely visible stripe pattern on their scales, some have dark spots alongside the stripes and some have no pattern at all.

The common garter snake has a dark, distinguishable head and a long slithery body. Its red and black, forked tongue is used as a detection device. This snake pops its tongue out of its mouth to collect chemicals in the air. It then places its tongue back into its mouth and inserts the fork into a special organ, called the Jacobson’s organ, on the roof of its mouth. The snake uses this process to detect scents like pheromones from other snakes and their next meal.


The common garter snake hibernates from late October until about early April in natural borrows or holes and under rocks. Once it emerges from hibernation, it begins the mating process. The common garter snake uses its tongue to seek out pheromones from potential mates. Once successfully mated, females give birth a few months later and each litter can vary from just a few to 80 snakes. When they are born they are about 12.5 to 23 cm long.

Common garter snakes can be found in just about any environment except water. Marshes, fields and forests are just a few of the habitats these snakes can occupy. During the winter months, common garter snakes hibernate in natural burrows, either in log piles or old rodent burrows, but sometimes come out to warm up their bodies by basking in the sun.


Since the common garter snake can live in just about any environment, they are the most widespread snake in the North America. This snake can be found throughout the continent, except in the dry southwestern states. Their range spreads down to mountain ranges in New Mexico to northern Mexico where remote populations are found.

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