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plains gartersnake

plains gartersnake (Thamnophis radix) [female] Photo © Drew R. Davis

plains gartersnake (Thamnophis radix) [male] Photo © Drew R. Davis

Features and Behaviors

The plains gartersnake averages 15 to 28 inches in length. The name “gartersnake” comes from the striped appearance of the body, similar to that of the garters that were once commonly used to support men’s socks. Three longitudinal stripes are found on the body with black spots between the stripes and below each side stripe. The stripe in the center of the back is yellow or orange while those on the sides are yellow-gray. The lips have black bars, and the gray-green belly has two rows of black spots. The back is brown or green. The scales are keeled (ridged).

The plains gartersnake may be found in the northern one-half of Illinois. This snake lives in river valleys, prairie ponds, sloughs, meadows and pastures. It was once common in vacant lots in cities. Active in the day, this snake may be seen basking in the sun. It takes shelter under objects on the ground. It is believed to overwinter in abandoned rodent burrows. When alarmed, the plains gartersnake may flatten its body and release fecal matter and an unpleasant musk from glands at the base of the tail. Mating occurs in the spring. The female gives birth to from five to 30 young from August through early October, the number depending on her size and age. The plains gartersnake eats frogs, toads, salamanders, fishes, tadpoles, earthworms, leeches, small mammals and birds.

Illinois Range


​Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: Squamata
Family: Natricidae

Illinois Status: common, native