Common Garter Snake
Thamnophis sirtalis • Order: Squamata, Suborder: Serpentes, Family: Colubridae, Subfamily: Natricinae, Genus: Thamnophis, Species: sirtalis
Venomous Status
Non-venomous/Mildly venomous
Danger Level
Harmless - poses no risk to humans or pets; accidental bites may cause minor localized irritation or swelling.
Geographic Range
Widely distributed throughout North America, ranging from the subarctic regions of Canada through most of the United States to northern Mexico.
Conservation Status
Least Concern (IUCN); very common and adaptable, though threatened locally by habitat loss and pesticide use.
Physical Description
The shed skin shown reveals keeled (ridged) scales and a pattern indicating longitudinal stripes or checkered spots. Live specimens typically have three yellow or greenish stripes and a slender body with round pupils.
Size & Dimensions
The shed shown appears to be approximately 18-24 inches. Adults typically range from 18 to 26 inches (46 to 66 cm), with a maximum recorded length of 54 inches.
Habitat
Generalist species found in forests, grasslands, fields, and suburban backyards, usually in close proximity to water sources like marshes, lakes, or streams.
Behavior & Temperament
Diurnal activity; generally shy and will flee when approached. If handled, they may release a foul-smelling musk or flatten their heads to appear larger.
Diet & Feeding
Feeds primarily on amphibians (frogs, toads, salamanders), earthworms, and small fish using active foraging and swallowing prey alive.
Reproduction
Ovoviviparous (gives birth to live young); typical litter sizes range from 10 to 40 neonates born in late summer.
Venom & Safety
Venom Type
Possesses a harmless mild neurotoxic venom in saliva delivered via enlarged rear teeth; lacks a complex delivery system. No medically significant venom to humans.
First Aid Advice
Wash any bite area with soap and water to prevent infection. No antivenom is required; seek medical attention only if an allergic reaction occurs.
Look-alikes
Ribbon snakes (Thamnophis saurita) which are more slender with higher stripe positions, and various Water Snakes (Nerodia spp.) which are larger and heavier-bodied.
Conservation Status
Least Concern (IUCN); very common and adaptable, though threatened locally by habitat loss and pesticide use.
Cultural Significance
One of the most recognizable snakes in North America; ecologically important for controlling pest populations and serves as food for many birds of prey.
Notable Features
Highly cold-tolerant; known for 'brumation' in large communal dens where hundreds of snakes may congregate during winter.