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 Nova Scotia and southern Canada down through the United States to the Gulf of Mexico and into parts of northeastern 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, with stable populations globally, though local populations face threats from habitat fragmentation, road mortality, and domestic predators.
Physical Description
Displays distinct longitudinal light-colored stripes running down a darker body, typically featuring a central dorsal stripe and two lateral side stripes, with keeled scales and a slender body shape.
Size & Dimensions
The pictured specimen appears to be a juvenile or small subadult measuring approximately 12 to 18 inches. Typical adults range from 18 to 26 inches, with maximum recorded lengths reaching up to 43 inches.
Habitat
Highly adaptable, found in diverse habitats including meadows, marshes, woodlands, grassy fields, and suburban lawns, typically near a permanent or temporary water source.
Diet & Feeding
An active forager feeding primarily on amphibians, earthworms, small fish, slugs, and occasionally small rodents or other reptiles, locating prey primarily through keen olfaction and Jacobson's organ.
Reproduction
Viviparous (live-bearing), giving birth to litters typically ranging from 10 to 40 or more young in the late summer, with mating occurring primarily in the spring shortly after emerging from brumation.
Look-alikes
Frequently confused with other striped snake species such as Ribbon Snakes (Thamnophis saurita) andlined snakes (Tropidoclonion lineatum), which can be distinguished by specific scale counts, body proportions, and stripe placements.
Conservation Status
IUCN Red List status is Least Concern, with stable populations globally, though local populations face threats from habitat fragmentation, road mortality, and domestic predators.
Cultural Significance
Serves an important ecological role in controlling invertebrate and amphibian populations, and is frequently encountered in North American suburban environments, making it a common subject for educational nature encounters.
Notable Features
Known for high tolerance to cooler temperatures, immunity to certain amphibian skin toxins, and complex communal brumation behaviors where hundreds of individuals gather in underground dens over the winter.