Common Garter Snakes are slender and stealthy, blending in with grass to ambush prey.
NPS Photo
Common Garter Snake Thamnopis sirtalis
The common garter snake is a slender, medium-sized snake.
Adults range from 18-30 inches in total length.
Typically, active from March to November. This is an active snake, but during the summer may shift activity to become more nocturnal to avoid the heat.
Identification
Individuals have a tan or pale yellow middorsal stripe extending down the entire length of their body.
The secondary coloration is typically tan, and an additional lateral stripe exists on each side of the body that occurs on scale rows two and three.
Diet
Their diet consists mostly of amphibians, earthworms, or other soft-bodied invertebrates.
These snakes will also eat other snakes when available.
Interaction with other animals
Predators include coyotes, foxes, other snakes, and most birds of prey.
When threatened, they often flatten and extend their bodies, showing the red color on their scales.
Upon capture, they will release a foul-smelling musk.
Last updated: January 9, 2024
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Contact Info
Mailing Address:
11149 U.S. Hwy. 16
Building B12
Custer,
SD
57730
Phone:
605 673-8300
The main phone line connects visitors with staff at the visitor center. Throughout the year, the phone line is monitored by staff on a daily basis, excluding holidays and days with limited visitor services. Please be advised that after-hours messages are not taken on the system; visitors are encouraged to call the visitor center during normal operations and speak with a park ranger for assistance.
