San Francisco Garter Snake Gets Protections In San Mateo County, CA

San Mateo County Planning Commission approves environmental enhancement project for the snake.
San Francisco Garter Snake Sheilalarsenusfws
Photo Credit: Sheila Larsen / USFWS

The San Francisco garter snake (Thamnophis sirtalis tetrataenia), a subspecies of Thamnophis sirtalis that is only known to exist on the San Francisco Peninsula in San Mateo County, got a boost in it habitat May 22 when the San Mateo County Planning Commission approved an environmental enhancement project for the snake.

Working with the land conservation agency Peninsula Open Space Trust (POST) and the San Mateo Resource Conservation District, a total of 16.7 acres of the snake’s habitat as well as that of its main prey, the California red-legged frog, will be improved. The 16.7 acres are part of a 65-acre plot of undeveloped farmland. It will be called the The Butano Farms San Francisco Garter Snake Habitat Enhancement Project. The plot is located in Pescadero on unicorporated land owned by POST.

“What’s great about the project is that it meets multiple goals as far as — first and foremost — enhancing the habitat for garter snakes and also grazing programming on the property,” Dan Olstein, director of land stewardship at POST told the San Mateo Daily Journal.

California Red Legged Frog

California red-legged frog. Gary M. Fellers, USGS

The U.S. Fish and Wildlife Service will analyze certain pesticides on their impact on wildlife in the United States.

The enhancements will include reducing woody encroachments into grasslands, removing invasive species and sediment removal of an upland pond as well as the creation of a basking site on the pond for the snake’s to thermoregulate. The hope is a deeper pond will make for a healthier part of the ecosystem for the snake and its main prey item, the red-legged frog.


The Return of Red-Legged Frogs to Southern California


The county planning commission approved a Coastal Development Permit for the proposal and work on enhancing the land will begin this summer, after a rainy season when the reptile is not as mobile. Funding for the project comes in part from Pacific Gas & Electric.

About the San Francisco garter snake and California red-legged frog

The California red-legged frog was made famous by Mark Twain’s short story, “The Celebrated Jumping Frog of Calaveras County.” Listed as threatened in 1996, Rana draytonii is the largest native frog in the Western United States. It grows from 1.5 to 5 inches in length and sports an olive or brown back and reddish legs and belly.

The San Francisco garter snake was placed on the Endangered Species list in 1967. It has been estimated that only 1000 to 2000 adult snakes remain in the wild. It feeds primarily on the California red-legged frog and can be found in densely vegetated bodies of water with ample areas for basking. The species is at risk due to decline of the California red-legged frog and the introduction of the American bullfrog to the garter snake’s natural range. The bullfrog feeds on the snake and the California red-legged frog.

Categories: Frog Amphibian Information & News, Snake Information & News, Wild Frogs & Amphibians