Plains Garter Snake

The plains garter snake is commonly found in meadows and prairies adjacent to water sources, such as marshes, streams, and ponds. In built-up areas of the Chicago area, it has been observed in abandoned buildings, trash heaps, and vacant lots. Populations in urban and suburban areas have been greatly reduced due to building activities and pesticide use. Its habitat range overlaps with that of the common garter snake (Thamnophis sirtalis) in many areas, and it is thought the two species may hybridize.

Geographic range. The snake ranges across a broad area of North America from as far north as central Alberta to as far south as Northern Texas and New Mexico. In the United States, it is also found in Iowa, eastern Wyoming, northern Kentucky, eastern Colorado, Minnesota, southern Wisconsin, Illinois, northwestern Indiana, Oklahoma, Nebraska and the northern half of Missouri. A small population is also in Ohio. In Canada, the species is also found in Manitoba. It can be found at elevations from 400 to 7,500 feet, but prefers to stay under 6,000 feet.

Described as "one of the most cold-tolerant snakes", on warmer winter days, it often comes out of hibernation to bask in the sun. It is most active between April and late October depending on location. Mating normally takes place in April or May and birth takes place between August and October. Courtship usually occurs near the communal hibernation site, and polygynous mating systems have been observed. The snake's typical diet consists of earthworms, slugs, and small amphibians, including the larvae of salamanders. It has also been observed eating small mammals and birds, such as bank swallows and eastern meadowlarks.