SLITHERING FOR SURVIVAL
DEVASTATING
DESTRUCTION
Diminishing food source
The habitat of the San Francisco Garter Snake is unfortunately restricted to the highly developed San Francisco Peninsula, with all known populations of this beautiful snake inhabiting scarce wetlands in San Mateo County (Miller, 2006).
Originally, its habitat would have stretched south from San Francisco into the Santa Cruz Mountains, but because of human-induced habitat loss the species is now isolated to a meager fraction of their previous range (US EPA, 2010).
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The principal food source of the San Francisco Garter Snake, the California Red-Legged Frog, is also severely endangered. Populations of the frog have declined 75% leaving its predators with less and less prey to sustain their own population (Kay, 1995). The boom in the invasive bullfrog populations which prey on the snake and its prey are largely because pet owners release their bullfrogs into local riparian corridors and wetland locations allowing their populations to rapidly multiply with other released pets, and leech into the niches of other native animals. In this way, the bullfrogs have affected San Francisco Garter Snake by creating interspecific competition, overeating and diminishing the California Red-Legged Frog populations resulting in little food left for the snakes. The endangerment of the native frog had a great influence on the endangerment its predator, the San Francisco Garter Snake (Swenty, 2016).
exploitation and detestation
Retrieved with permission from Sebastian Kennerknecht
The beautiful, unique coloring and markings of the San Francisco Garter Snake, “one of the most beautiful serpents of North America” (Roberson, 2004), make the collection of the snake by reptile fanciers and dealers of high demand and very profitable (US Fish and Wildlife Services, 1985).
The U.S. Fish and Wildlife Service lists the San Francisco Garter Snake is listed as “endangered” because it is dangerously threatened by loss of critical habitat and crippling, illegal over-collection (Szalay, 2014).
ANIMAL ADVOCATES
LACKING LEGISLATION, LEADERS, AND LAWS
Many organizations have been working to protect this snake since it was one of the first species to be protected under the US Endangered Species Act when it was created in 1973 (US EPA, 2010). The U.S. Fish and Wildlife Service (FWS) developed a recovery plan for the San Francisco garter snake in 1985, but little action has been taken (US EPA, 2010).
There are six existing locations of breeding San Francisco garter snakes, which are being monitored for population numbers. Numbers do not need to be very high in order to be delisted from the federal endangered species list- only 200 individuals are needed at each of the six existing locations.
There have been several campaigns started by local populations in order to protect the small critical habitats, but legislation has been difficult to pass despite the fact that this crucial species’ population is dwindling. Much of that land is also the habitat for another endangered species, the California red-legged frog (Miller, 2009).
Sharp Park is public land that’s a significant habitat for both the SF garter snake and the California red-legged frog, its preferred prey. There have been movements to create a sanctuary here for these two endangered species, but legislation has not passed. Sharp Park remains developed public land, including an eighteen hole golf course (Miller, 2009).
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The threats posed to the San Francisco Garter Snake by, primarily, human development and a disappearing food source are limiting the species’ biotic potential and making population recovery of the snake increasingly difficult. There are enough individuals in the population that the species is unlikely to become functionally extinct but if humans keep making changes for the worse, these poor innocent serpents will first face the peril of becoming ecologically extinct, falling out of their niche allowing the bullfrogs to take dictatorship over their community, then local extinction. In other words, being wiped out forever. This may seem far off in the future, but human interference has amplified background extinction rates of 1-5 species becoming extinct to an enormous 1,000-50,000 species, gone from the Earth never to return because on human activities and interference (Center for Biological Diversity, 2017). This case study is the perfect application of how the environmental acronym, HIPPCO, affects biodiversity. Specifically H, habitat destruction, I, invasive species, and O, overexploitation.
Urban growth in the San Francisco Bay Area drastically increased in comparison to previous decades, with populations increasing from 1.7 million in 1940 to 2.7 million in 1950.
The association between human population growth and urban expansion is seen to directly impact the local species population due to habitat fragmentation and geographic isolation. Habitat loss has been detrimental to the snake’s population, especially through the Skyline Boulevard development and sag ponds. Through the post World War II housing boom to the 1960’s, nearly all of the ponds that were the snakes’ habitats were drained and developed. This led to the snake being one of the first animals on the endangered species list, added in 1966 (Golden Gate National Parks Conservancy, 2017).
In 1985, 23 of the 28 (82%) San Francisco Garter Snake populations sites were subject to human disturbance or threat (US Fish and Wildlife Service, 1985).
Alteration and isolation of habitats resulting from urbanization is the principal reason for drastic decline of the San Francisco Garter Snake population. In 1985, 23 of the 28 (82%) San Francisco Garter Snake populations sites were subject to human disturbance or threat (US Fish and Wildlife Service, 1985). It has only gotten worse since then. This devastation to the coastal wetlands of the Bay Area have sorrowfully pushed the San Francisco Garter Snake to endangerment, but with new protection from the Endangered Species Act, saving the snake means that their habitat must be saved along with them. This has led to extensive wetland restoration and preservation, and discouraged more urbanization.
Why can’t I release my pet back into the wild?
The bullfrogs are disrupting the balance among the food chain by weakening a predator-prey link in the chain and trying to replace the relationship with their own destructive tendencies. By spreading the word to have local pet store stop selling bullfrogs or telling pet owners not to release their unwanted animals into the wild, we can begin to start controlling this out of control invasion and takeover by the bullfrog.
Although some praise and value the allure of this serpent, many humans have baseless fear and despise all kinds of snakes. Scientists have found that hatred of snakes is not found in babies and very young children,but that they learn it through experience, especially through portrayal in the media. Species which are hated are likely to be endangered because of the threats humans pose to them (Moskowitz, 2008). These snakes are often persecuted by humans who are scared of them, and are killed or harmed as a result (Zimmerman, 2013).
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The introduction of bullfrogs to the area has been detrimental to the balance of many in the ecosystem; for the San Francisco Garter Snake and the California red-legged frog, this could mean extinction (Swenty, 2016). These snakes prey on juvenile bullfrogs and if their populations were larger, they might be able to restore the balance in the ecosystem.
​Unfortunately, population numbers are not close to delisting or downlisting quantities at this point (Cummings, 2010).
The San Francisco Zoo has the only SFGS in San Francisco (San Francisco Garter Snake, 2017). The zoo has also started restoration projects at Mori Point, including youth volunteers and Zoo staff, to participate in habitat restoration efforts in collaboration with Golden Gate National Recreation Area to benefit San Francisco Garter Snakes and the threatened California red-legged frog (Restoring Native Habitat, 2017).
Non-profit organizations working to protect the species include the Center for Biological Diversity, the Central Valley Herpetological Society, Save the Frogs, and Wild Equity Institute (Miller, 2009).
In 2008, a campaign was built to re-establish a unique back barrier lagoon habitat at Sharp Park in Pacifica, California — public land that's a significant habitat for the San Francisco Garter Snake as well as the California Red-Legged Frog. In 2008, the same people filed a notice of intent to sue the city of San Francisco for illegally killing and harming San Francisco garter snakes at Sharp Park Golf Course. Along with adjacent Mori Point, which lies within the Golden Gate National Recreation Area, Sharp Park provided one of the last great restoration opportunities on California's central coast (Miller, 2009). According to the Protect the San Francisco Garter Snake Facebook page, San Francisco’s Mayor Ed Lee just vetoed a legislation that would have saved the Sharp Park Wetlands. The City plans to use taxpayer money to pump the Sharp Park Wetlands out to sea instead of restoring this vital habitat.
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They’re running out of food, water and shelter… and we’re the ones taking it away.
Despite having been federally protected since 1966, the SF garter snake is still endangered.
The Center for Biological Diversity filed a notice of intent to sue the city of San Francisco for illegally killing and harming San Francisco garter snakes at Sharp Park Golf Course, which lies within the Golden Gate National Recreation Area (Miller, 2009). The Center is challenging the Environmental Protection Agency's registration and authorization for use of 44 toxic pesticides in and upstream of habitats for San Francisco Bay Area endangered species, including the San Francisco garter snake (Miller, 2009).
San Francisco Garter Snakes are federally protected by the U.S. Endangered Species Act. Almost no action is being taken on a local level by county, city, or state governments, and therefore the snakes have little real protection. The remaining habitats for these creatures are on private land, so data collection and surveying are very difficult; this makes protection efforts virtually impossible (Swenty, 2016).