Status (as of 1967): ENDANGERED
San Francisco Garter Snakes are slender with a burnt orange-colored head and a greenish-yellow dorsal stripe edged in black, bordered by a red stripe, which may be continuous or broken with black blotches, and a black stripe. Their underside varies from a characteristic greenish-blue to blue. They can reach a length of 3ft or more.
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Threats to the SpeciesInvasive Species: Non-native bullfrogs in California eat many California red-legged frogs, an essential prey species for SF garter snakes.
Habitat Loss: Agriculture, urbanization, recreation. Pesticides: Fumigation practices threaten populations. |
Range and HabitatHabitat: They prefer densely vegetated pond near an open hillside where they can sun themselves. Emergent and bank-side vegetation such as cattails, bulrushes, and spike rushes are used for cover. They are most often found around ponds and marshes that support large populations of frogs.
Range: California counties - Alameda, San Francisco, Santa Clara, Santa Cruz, and, especially, San Mateo |
Behavior |
Life Cycle |
San Francisco Garter Snakes are diurnal. In the summer, most activity occurs morning and afternoon. In spring, fall, or higher altitudes, most activity occurs in the afternoon.
Co-occur with other species of garter snake: aquatic garter snake, coast (terrestrial) garter snake Usually re-placed by and can intergrade with: red-sided garter snake Prey: Primarily California red-legged frog; also amphibians/small fish: Pacific legged frogs, Pacific tree frogs, California tree frogs, California newts, Western toads, juvenile bullfrogs (but not adult bullfrogs), and mosquitofish Predators: Bullfrogs |
Fall/Spring
Mating: Females can store sperm through the winter and bear young in the summer. Jun - Sep Live birth: Litters average 16 young. 2 Years Sexual maturity reached. 8 - 15 Years Lifespan in captivity. (Unknown in the wild) |
Resources
- Recovery Plan for the San Francisco Garter Snake, Thamnophis Sirtalis Tetrataenia. California Department of Pesticide Regulations. California Department of Pesticide Regulations, 2013. Web.
- "Species Accounts - Reptiles." California Department of Fish and Wildlife. California Department of Fish and Wildlife, n.d. Web.
- "Species Profile for San Francisco Garter snake (Thamnophis sirtalis tetrataenia)." ECOS Environmental Conservation Online System. U.S. Fish & Wildlife Service, n.d. Web.