Aquatic Garter Snake

Thamnophis atratus

Reptiles & AmphibiansIn the app

Length can range from 18-40 inches (46–102 cm). Dorsum varies from gray to brown to black; may possess a yellow stripe running lengthwise on back. Some individuals observ…

How to identify

Length can range from 18-40 inches (46–102 cm). Dorsum varies from gray to brown to black; may possess a yellow stripe running lengthwise on back. Some individuals observed to have small dark blotches on sides. Belly is greenish and throat can be white or yellow. Head is only slightly larger than neck. Females bear live young any time between late summer and early fall. Each brood usually consists of three to 12 young.

Range

West coast of America covering southwestern Oregon and western California north of Point Conception.

Habitat

Usually is located in water including quickly flowing streams and slowly flowing streams; streams can be rocky or soft bottomed. Also inhabits small creeks, lakes, and ponds. Surrounding area can be forest or chaparral. Spends a great deal of its time in the water, but can also be found basking in the sun on banks or boulders near water. Diet consists of food found in the water including fish, tadpoles, salamanders and frogs.

Variations

Subspecies Oregon Gartersnake, or *Thamnophis atratus hydrophilus*, usually does not possess yellow stripe running down back. If it is present, it is usually only on the back of neck. Tail underside is orange or pinkish.