Common Garter Snake
Thamnophis sirtalis • Order: Squamata, Suborder: Serpentes, Family: Colubridae, Subfamily: Natricinae, Genus: Thamnophis, Species: T. sirtalis
Widely distributed throughout North America, ranging from the sub-Arctic regions of Canada down through the United States to parts of northern Mexico.
Look up Common Garter Snake in the Snake Encyclopedia →Family
Order: Squamata, Suborder: Serpentes, Family: Colubridae, Subfamily: Natricinae, Genus: Thamnophis, Species: T. sirtalis
Conservation
IUCN Red List status is Least Concern, as the species is widespread, highly adaptable, and maintains large populations across its range, though local populations can face threats from habitat loss and road mortality.
Physical Description
The head shows distinctive vertical dark bars along the labial (lip) scales, a dark stripe running backward from the eye, and keeled dorsal scales giving a textured appearance. The visible eye features a round pupil.
Size & Dimensions
Adults typically range from 46 to 137 cm (18 to 54 inches) in total length. The specimen pictured appears to be a medium-sized individual or adult based on head proportions.
Habitat
Found in a diverse range of habitats including forests, fields, grasslands, marshes, and the edges of ponds and streams, often near water sources. Generally found from sea level up to elevations of over 8,000 feet.
Diet & Feeding
Primarily carnivorous, feeding on a wide variety of prey including amphibians, earthworms, small fish, mice, and other small animals. They actively forage for prey using keen senses of smell and tongue-flicking.
Reproduction
Ovoviviparous, giving birth to live young rather than laying eggs. Mating typically occurs in the spring shortly after emerging from hibernation, resulting in litters that can range from 10 to 40 or more offspring.
Conservation Status
IUCN Red List status is Least Concern, as the species is widespread, highly adaptable, and maintains large populations across its range, though local populations can face threats from habitat loss and road mortality.
Cultural Significance
Commonly encountered in suburban backyards and agricultural areas, making them one of the most frequently observed snakes by humans. They play an important ecological role in controlling populations of amphibians and invertebrates.
Notable Features
Known for their great adaptability, cold tolerance allowing them to inhabit northern latitudes, and communal hibernation habits where hundreds of individuals may overwinter together in hibernacula.