Common Gartersnake
Thamnophis sirtalis • Order: Squamata, Suborder: Serpentes, Family: Natricidae (or Colubridae), Subfamily: Natricinae, Genus: Thamnophis, Species: Thamnophis sirtalis
North America, widely distributed across the United States, southern and central Canada, and parts of northern Mexico.
Look up Common Gartersnake in the Snake Encyclopedia →Family
Order: Squamata, Suborder: Serpentes, Family: Natricidae (or Colubridae), Subfamily: Natricinae, Genus: Thamnophis, Species: Thamnophis sirtalis
Conservation
Least Concern (IUCN Red List). Abundant across most of its range, though local populations may face habitat loss or pesticides.
Physical Description
Features a distinct yellowish dorsal stripe flanked by dark brown or black sides with a checkerboard pattern of light flecks. The chin and labial scales are pale yellow-green, the eye has a round pupil, and dorsal scales are heavily keeled.
Size & Dimensions
Specimen appears to be a small adult/subadult around 18-24 inches (45-60 cm) long. Typical adult size ranges from 18 to 42 inches (46 to 106 cm).
Habitat
Extremely adaptable; found near water sources like ponds, streams, marshes, and damp woodlands, as well as fields, suburban gardens, and parks from sea level up to moderate elevations.
Diet & Feeding
Active hunter feeding mainly on amphibians (frogs, toads, salamanders), earthworms, small fish, slugs, and occasionally small mammals or nestling birds.
Reproduction
Viviparous (gives birth to live young). Mating occurs in spring, and females give birth to 10-40 (sometimes up to 80) live young in late summer.
Look-alikes
Ribbonsnakes (Thamnophis saurita / T. proximus), which are slenderer with lateral stripes on scale rows 3 and 4, whereas gartersnakes typically have stripes on rows 2 and 3.
Conservation Status
Least Concern (IUCN Red List). Abundant across most of its range, though local populations may face habitat loss or pesticides.
Cultural Significance
One of the most widely recognized and common snakes in North America, playing a major ecological role in controlling pest populations and aquatic prey, and frequently encountered in yards and gardens.
Notable Features
Red-tipped tongue visible in motion, heavily keeled dorsal scales, striking checkerboard lateral pattern, and resistance to tetrodotoxin (TTX) found in prey such as toxic newts.