If garter snakes are not the most widely recognized and distributed snake in North America, they are certainly near the top of the list. They can be found across the state in a variety of habitats where they feed on prey such as insects, earthworms, frogs, etc.. Some of you may have noticed that the color seems to vary quite a bit. It might help to know that there are two species of garter snakes native to North Dakota, the common garter snake and the plains garter snake.
The plains garter snake (Thamnophis radix) is probably the most frequently observed of the two species. Their color is brown to tan with three stripes. The middle stripe is often bright yellow or orange with stripes on the side perhaps having a bluish-green cast. The color between the middle stripe and the lateral stripes can vary from black to black and tan.
The common garter snake (Thamnophis sirtalis) is noticeably different and is also known as the red-sided garter snake. This species has one bright yellow stripe down back, and as the red-sided name implies, also has alternating red and black spots along the sides. I will leave it up to you as to whether it is black with red patches or red with black patches. At any rate, the red color is quite noticeable and is a key characteristic in distinguishing the two species
Both species are known to have the rather unusual habit of congregating by the hundreds to hibernate. These hibernacula are below the frost line and provide protection from predators and may be used for several years. No doubt some of you have heard about the Narcisse (“Narsis”) hibernacula north of Winnipeg where as many as 50,000 red-sided garter snakes congregate to hibernate. It is generally considered to be the largest concentration of the species in the world.
Upon emerging from hibernation, the mating season commences. Through communication by pheromones, a large “mating ball” composed of a female and up to a couple dozen male suitors may form. Once the mating is over the female leaves for a suitable place to eventually give birth to her young. Gestation will last two to three months before the females give live birth in late summer to somewhere around 10-50 six inch long young.