Garter Snake

The garter snake is a common species of non-venomous snake found in the US, Central America, Mexico, and southern Canada. Find out more about it here.

The term ‘Garter Snake’, usually also called grass or garden snakes, refers to around twenty species of non-venomous snakes that are found all over the US. They can also be found in abundant numbers in Central America, Mexico, and southern parts of Canada. Most garter snakes are banded or striped lengthwise, with some having spots between the stripes. They can grow up to 60 cm, or 2 feet, in length. Less aquatic compared to the water snakes that they are related to garter snakes can usually be found in the vicinity of water in dry areas and are distributed widely in moist areas. The female garter snake gives birth to large litters of live young, often numbering up to 50, or even more.
When hunting, the garter snake relies chiefly on its sight, hearing by sensing the vibrations on the ground, smell and taste. The last two senses are used in combination with the Jacobson’s organ, which occurs in the mouth’s roof. Garter snakes are very agile, a feature which helps them to capture their prey successfully. They hunt for their prey in the cooler parts of the day, such as early morning, early evening, and even late afternoon.

Like all snakes, the garter snake is carnivorous. It eats just about anything that it can overpower such as frogs, rodents, fish, birds, lizards, leeches, insects, earthworms, and slugs. When they live near water, they hunt and eat other aquatic animals. They swallow their food whole. Even though their diet comprises mostly of live animals, sometimes they will even eat eggs.
Due to being small in size, garter snakes have a tendency of cooling down and heating up quickly. Similar to other reptiles, garter snakes bask in the sun in order to warm up. Garter snakes try and maintain the temperature of their body between 72-88 degrees F, or 22-32 degrees C, with their ideal range being 84-86 degrees F, or 29-30 degrees C. Garter snakes can continue to function in cool temperatures going down to 60 degrees F, or 16 degrees C as well as when it rises up to 93 degrees F, or 34 degrees C.
Many species of garter snakes have to hibernate in the winter because of the severe cold as well as the reduction of the hours available to them for basking. This dormant period is also needed to induce mating behaviors. The red-sided garter, which is one of the species found in the northern regions, ranging up to Canada, migrates to its hibernaculum, which is usually the same one that it uses year after year. In fact, garter snakes can travel distances of up 3.5 km to their site of hibernation.

When garter snakes hibernate, they do it in aggregations, which means hundreds of them collecting in the same hibernaculum, where they spend the winter together and also have access to each other for the breeding season in spring. In the cold weather, the hibernaculum’s temperature never goes below 27-39 degrees F, or 3-4 degrees C, which are the temperatures wherein the garter snake can remain safely without it impacting its health in general or causing much loss of weight. Such dormancy can be sustained by the garter snake by it feeding heavily in the latter part of summer.
With the arrival of spring, it can take up to 2 or more weeks for hibernaculum to warm up. During this period, it comes awake slowly, some even going out of the den for short forays, coming back into the hibernaculum in the night in order to stay away from the night temperatures outside which can usually be still cold. This helps them not get caught out in the open in a late frost.