U.S. Fish & Wildlife Service

Sacramento Fish & Wildlife OfficeServing the people, conserving the fish, wildlife, and plants of California

A Unit Of The Pacific Southwest Region

San Francisco garter snake returns to its namesake city

San Francisco garter snake

Photo Credit: USFWS

On Thursday, June 2, 2005, the San Francisco Zoo hosted a unique event to mark the return of one of California 's most endangered and beautiful species to its native city. U.S. Assistant Secretary of Interior P. Lynn Scarlett joined San Francisco Zoo Director Manuel Mollinedo and the U.S. Fish and Wildlife Service in the first public viewing of recently acquired San Francisco garter snakes.

Scarlett, Assistant Secretary for Policy, Management and Budget and Deputy Secretary-Designate, and officials from local and national environmental agencies spoke on the importance of bringing these endangered snakes back to San Francisco and the continuing plight of this species in the wild. The San Francisco garter snake has been absent from North American zoos since 2003 and is the focus of new efforts to increase wild populations along the San Francisco peninsula.

"We at the Interior Department and the U.S. Fish and Wildlife Service are pleased to partner with the San Francisco Zoo to bring one of the world's most beautiful snakes back to one of the world's most beautiful cities." Scarlett said.

San Francisco 's own native snake, the San Francisco garter snake ( Thamnophis sirtalis tetrataenia ) is a subspecies of the common garter snake and was found historically from San Francisco to Santa Cruz. Today, with a wild population limited to coastal San Mateo County and other small pockets, the San Francisco garter snake is considered critically endangered in the wild because of the loss of habitat.

Kids looking at San Francisco garter snake

Photo Credit: USFWS

In an effort to actively conserve and recover the San Francisco garter snake, the U.S. Fish and Wildlife Service established an internal San Francisco Garter Snake Working Group in 2003 to design and implement specific conservation actions while updating the recovery plan. The working group identified and developed a multi-phase process for restoring and enhancing captive and wild San Francisco garter snake populations.

The first phase of the plan is to restore and enhance habitat for the wild population and the second is to restore the North American captive population by importing stock from Europe and placing them in zoos accredited by the American Zoo and Aquarium Association. Subsequent phases include the possibility of zoos holding wild snakes for short periods as habitat restoration projects progress, a possible "head-start" program for juvenile snakes, and preparations for captive propagation, if such measures are called for to prevent the extinction of the species in the wild.

Ten juvenile San Francisco garter snakes of five mixed gender pairs were flown from the Netherlands to the U.S. These ten snakes will be used as part of a public education effort that will include classroom visits from the Zoo Mobile, on-site presentations, inclusion in VIP tours and interpretive graphic displays, that are intended to inform local residents about the plight of the snake. The pencil-thin, 18-inch snakes, with turquoise bellies and distinctive red and black striped bodies, will eventually grow to four feet in length. These snakes will be available for the public to see up-close at the Zoo's Koret Animal Resource Center, part of the Children's Zoo.

Deputy Secretary of the Interior Lynn Scarlett

Photo Credit: USFWS

"The San Francisco garter snake is one of the most beautiful snakes in the world," said Manuel Mollinedo, executive director and president of the Zoo. "This is our native snake and we want people to recognize this as a special animal that may occur in their own backyard. Hopefully, people will be inspired to protect it for future generations."

The San Francisco garter snake was listed as a federally-endangered species in 1967 and as a state-endangered species in May 1971 due to habitat loss from urbanization and agricultural conversion in areas of established garter snake populations. The drainage of ponds and marsh sites where snakes feed, in addition to changes in water quality and/or the introduction of the bullfrog into its ecosystem, has resulted in a corresponding decline in its core foods: the threatened California red-legged frog and the Pacific tree frog. The captive population, once thriving in the 1990's, went extinct in 2003 when the last remaining snake in captivity died at the San Francisco Zoo, where they were once considered the jewels of the collection.

Meanwhile, the U. S. Fish and Wildlife Service is working with the California Department of Fish and Game, the National Park Service, Golden Gate National Parks Conservancy, the California Department of Parks and Recreation, and lots of other public and private partners to enhance wetland and upland habitat for the San Francisco garter snake. Their efforts are aimed at nurturing wild populations of the snake so that, eventually, it can be taken off the endangered-species list.

For instance, the National Park Service in partnership with the Fish and Wildlife Service created two wetlands in November 2004 to enhance breeding habitat for California red-legged frogs and Pacific tree frogs at Mori Point, on Golden Gate National Recreation Area lands in Pacifica. Since frogs constitute the majority of a San Francisco garter snake's diet, this habitat restoration effort was designed to produce adequate prey for the snakes while emulating the area's natural topography.

Last updated: November 9, 2017