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 southern Canada down through the United States to the Gulf of Mexico, spanning diverse biomes.
Look up Common Garter Snake in the Snake Encyclopedia →Family
Order: Squamata, Suborder: Serpentes, Family: Colubridae, Subfamily: Natricinae, Genus: Thamnophis, Species: T. sirtalis
Conservation
Least Concern according to the IUCN Red List, facing no major population-level threats although local populations are impacted by habitat loss and road mortality.
Physical Description
Features a slender body with a patterned dorsum showing dark blotches and faint striping, a distinct head shape slightly wider than the neck, round pupils, and keeled scales giving a textured appearance.
Size & Dimensions
The pictured specimen appears to be a juvenile, approximately 12 to 18 inches long. Adults typically range from 18 to 54 inches in total length.
Habitat
Highly adaptable, found in fields, woodlands, marshes, drainage ditches, and suburban lawns, typically near permanent or temporary sources of water.
Diet & Feeding
Active forager feeding primarily on amphibians, earthworms, small fish, and occasionally small mammals or birds, consuming prey live without constriction.
Reproduction
Viviparous, giving birth to live young rather than laying eggs. Mating occurs in the spring after emerging from brumation, yielding litters typically ranging from 10 to 40 offspring.
Look-alikes
Frequently confused with other natricine snakes such as ribbon snakes (Thamnophis saurita) and water snakes (Nerodia), which can be distinguished by specific striping patterns, scale counts, and body proportions.
Conservation Status
Least Concern according to the IUCN Red List, facing no major population-level threats although local populations are impacted by habitat loss and road mortality.
Cultural Significance
Commonly encountered in suburban areas throughout North America, serving an important ecological role in controlling amphibian and invertebrate populations while frequently kept as educational pets.
Notable Features
Exhibits a remarkable degree of color and pattern variation across its extensive geographic range and possesses specialized immunity to the toxins found in some of its amphibian prey.