Living on the Edge

Endangered critters right under your nose in San Francisco.

Diamonds in the Urban Rough: Three Animals Struggle to Make It

It’s easy to focus on the natural beauty and urban adventures of the San Francisco Bay Area. But did you know there are endangered species struggling to survive, right outside your door?

Look closely, and you may find a rare butterfly, a beautifully colored snake or a shy little bird living on the edge in our urban paradise. But be careful not to disturb them.

Here are three diamonds in the urban rough:

Mission Blue Butterfly

Location: Golden Gate National Recreation Area 

First discovered in San Francisco in 1937 and endangered since 1976, this light-blue iridescent beauty is a treasure to find. Many factors have contributed to its endangered status. The mission blue butterfly sips nectar from many different flowers, but the larvae only eat the leaves of three kinds of lupines. In wet years, a fungus can kill these plants. If invasive shrubs or trees start growing in the butterflies’ grassland habitat and push out the lupines, this could also make it hard for the caterpillars to find enough to eat. Of course, even at the best remaining sites, residential development can destroy habitat, wiping out populations of these butterflies.

The San Francisco Recreation and Parks Department has restored a population of mission blues to Twin Peaks and is working with volunteers to maintain their habitat. Partners include Golden Hour Restoration Institute, the California Native Plant Society, Nature in the City, the California Fish and Wildlife Service and others.

Watch this video to learn more about the mission blue butterfly and efforts to protect it.

San Francisco Garter Snake

Location: Marshes near San Francisco Airport

Endangered since 1967 and considered one of the most beautiful snakes in North America, this slender multi-colored reptile is one of the gentlest and shyest of snakes. It’s also one of California’s rarest. Agricultural and urban development and the resulting destruction of wetlands containing amphibian prey have really hurt them. Their beauty has also been a liability, driving illegal collecting for the pet trade.

The San Francisco garter snake’s elusive nature makes it difficult to conduct recovery and monitoring efforts, but there is a recovery plan for the species.

California Clapper Rail

Location: Don Edwards San Francisco Bay National Wildlife Refuge

This long-billed bird with a white rump has been endangered since 1970 but survives in a few locations, including the tidal marshes of San Francisco Bay, which houses the largest population in California. The secretive chicken-sized bird rarely flies and is active in the mornings and late evenings.

California clapper rail numbers are precariously low due to introduced predators such as rats, red foxes and housecats. Destruction and alteration of their marsh habitat have also been major factors in their decline. Removal of an invasive cordgrass, for instance, benefits the marsh ecosystem but makes life harder for the rails, who build their nests near the cordgrass and use it for cover. Recognizing this dilemma, conservationists take special care in removing the invasive plants, ensuring that critical habitat is kept intact. And homeowners who live near marshes help protect the rails by keeping their cats inside their homes.

It may be an (urban) jungle out there, but through the efforts of many groups and individuals, our rare and important Bay Area creatures can still have a place to call home. 

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