Common Garter Snake
Thamnophis sirtalis • Order: Squamata, Suborder: Serpentes, Family: Colubridae, Subfamily: Natricinae, Genus: Thamnophis, Species: T. sirtalis
North America, extending from southern Canada through the United States to northern Mexico, absent only from parts of the arid southwest.
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, as it remains widespread and adaptable, though localized populations face threats from habitat loss and road mortality.
Physical Description
Dark body coloration with characteristic distinct vertical black bars along the labial scales (lips), heavily keeled scales, round pupils, and a moderately stout head clearly distinct from the neck.
Size & Dimensions
Specimen head visible in grass; adult species typically range from 46 to 137 cm (18 to 54 inches) in total length.
Habitat
Found in a wide variety of habitats including meadows, marshes, woodlands, and along the edges of streams, ponds, and ditches, often near water.
Diet & Feeding
Eats a diverse diet consisting mainly of amphibians, earthworms, fish, and small mammals, actively foraging using both keen eyesight and a well-developed sense of smell.
Reproduction
Viviparous (gives birth to live young), producing litters ranging from 10 to 40 or more offspring in the late summer.
Conservation Status
IUCN Red List status is Least Concern, as it remains widespread and adaptable, though localized populations face threats from habitat loss and road mortality.
Cultural Significance
Commonly encountered in suburban yards across North America, serving an important ecological role in controlling pest and amphibian populations.
Notable Features
Exhibits distinct dark vertical bars on the supralabial scales, which is a key diagnostic feature for identifying certain subspecies of garter snakes.