Common Garter Snake
Thamnophis sirtalis • Order: Squamata, Suborder: Serpentes, Family: Colubridae, Subfamily: Natricinae, Genus: Thamnophis, Species: sirtalis
Widely distributed across North America, from subarctic regions of Canada to the Gulf Coast of Mexico and from the Atlantic to the Pacific coasts.
Look up Common Garter Snake in the Snake Encyclopedia →Venomous Status
Non-venomous (though they possess a Duvernoy's gland that produces a mild neurotoxic secretion, they lack true fangs).
Danger Level
Harmless; they pose no significant threat to humans or pets beyond potential minor irritation or infection from a bite.
Family
Order: Squamata, Suborder: Serpentes, Family: Colubridae, Subfamily: Natricinae, Genus: Thamnophis, Species: sirtalis
Conservation
Least Concern (IUCN). They are one of the most common and widespread snake species in North America.
Physical Description
Slender body with keeled scales. Typically features a distinct dorsal stripe (cream, yellow, or greenish) and two lateral stripes on a background of dark olive, brown, or black. Checkered patterns are often visible between stripes.
Size & Dimensions
Specimen appears to be an adult of approximately 18-24 inches. Species typically ranges from 18 to 26 inches, with record lengths reaching 48 inches.
Habitat
Highly adaptable, found in meadows, marshes, woodlands, and hillsides, often near water sources. They are common in suburban gardens and parks at elevations from sea level to high mountains.
Behavior & Temperament
Diurnal and active forager. Generally docile but may flatten its body, strike, or release a foul-smelling musk and feces from the cloaca as a defensive mechanism when handled.
Diet & Feeding
Generalist carnivores that consume earthworms, amphibians, fish, slugs, and occasionally small rodents or birds. They use an active foraging strategy and hunt by scent and sight.
Reproduction
Ovoviviparous (gives birth to live young). Litters typically range from 10 to 40 young, born in late summer or early fall.
Venom Profile
Non-venomous - no medically significant venom. Secretions may cause mild swelling or itching in sensitive individuals.
Look-alikes
Ribbon Snakes (Thamnophis saurita) which are more slender with stripes on scale rows 3 and 4, and various Water Snakes (Nerodia spp.) which lack the distinct longitudinal stripes.
Conservation Status
Least Concern (IUCN). They are one of the most common and widespread snake species in North America.
Cultural Significance
Ecologically vital as both predator and prey; they are frequently the first snake encountered by enthusiasts and help control garden pests like slugs and snails.
Notable Features
Noted for being one of the most cold-tolerant snake species, capable of being active in cooler temperatures that would render other reptiles dormant.