Snake Identifier
Common Garter Snake

Common Garter Snake

Thamnophis sirtalis • Order: Squamata, Suborder: Serpentes, Family: Colubridae, Subfamily: Natricinae, Genus: Thamnophis, Species: sirtalis

North America, ranging from subarctic regions of Canada through most of the continental United States (excluding parts of the Southwest) to Northern Mexico.

Look up Common Garter Snake in the Snake Encyclopedia →
Back to Snake Identifier

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 widely distributed snake species in North America.

Physical Description

Characterized by three longitudinal yellow or cream-colored stripes on a dark green, brown, or black ground color. The head is slightly wider than the neck, with large eyes and round pupils. Scales are keeled (ridged).

Size & Dimensions

The specimen in the image appears to be an adult, approximately 18-24 inches. The species typically ranges from 18 to 36 inches, with a record maximum around 54 inches.

Habitat

Extremely versatile; found in meadows, marshes, woodlands, and suburban gardens. They prefer areas near water but are frequently found in terrestrial microhabitats like leaf litter and under logs.

Diet & Feeding

Generalist carnivores; they consume earthworms, slugs, frogs, toads, salamanders, and small fish. They do not constrict; they use their strong jaws to swallow prey alive.

Reproduction

Viviparous (gives birth to live young). Litters typically range from 10 to 40 neonates, born in late summer or early autumn.

Conservation Status

Least Concern (IUCN). They are one of the most common and widely distributed snake species in North America.

Cultural Significance

Highly beneficial in gardens for pest control, specifically for managing slug and rodent populations. They are often a 'starter' snake for budding naturalists due to their abundance.

Notable Features

Garter snakes are one of the few predators that eat amphibians such as Rough-skinned Newts.

Identified on 4/17/2026
Common Garter Snake - Thamnophis sirtalis | Snake Identifier