Common Garter Snake
Thamnophis sirtalis • Order: Squamata, Suborder: Serpentes, Family: Colubridae, Subfamily: Natricinae, Genus: Thamnophis, Species: T. sirtalis
Widespread across North America, ranging from the Atlantic to the Pacific, extending from subarctic Canada down through much of the United States to the Gulf of 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, due to very wide distribution, high adaptability, and large overall population size.
Physical Description
Features three distinct longitudinal light-colored stripes (one vertebral and two lateral) running down a dark body, with reddish or checkered markings interspersed between the stripes. The head is slightly distinct from the neck with rounded snout and dark labial scales.
Size & Dimensions
Specimens typically range from 46 to 130 cm (18 to 51 inches) in total length, with adult females generally larger than males.
Habitat
Highly adaptable, found in diverse habitats including meadows, marshes, woodlands, and along the edges of streams, ponds, and lakes, ranging from sea level up to high elevations.
Diet & Feeding
Diet is opportunistic and varied, including amphibians (frogs, toads, salamanders), earthworms, small fish, and occasionally small mammals or birds. They hunt actively using keen senses of smell and tongue-flicking.
Reproduction
Viviparous (giving birth to live young). Mating occurs primarily in spring shortly after emerging from brumation, and females can give birth to litters ranging from 10 to as many as 80 young.
Look-alikes
Frequently confused with other garter snake species (Thamnophis species) and ribbon snakes (Thamnophis saurita). Distinguished by scale count rows, specific stripe positioning, and labial scale markings.
Conservation Status
IUCN Red List status is Least Concern, due to very wide distribution, high adaptability, and large overall population size.
Cultural Significance
Often encountered in suburban gardens and parks, playing an important role in controlling amphibian and insect populations. They are frequently kept as educational pets due to their hardy nature.
Notable Features
Known for participating in massive communal brumation sites (hibernacula) where hundreds or thousands of individuals gather to overwinter, and exhibiting complex pheromone-based mating behaviors upon emergence.