Threatened and Endangered Species


An "endangered" species is one that is in danger of extinction throughout all or a significant portion of its range.  A "threatened" species is one that is likely to become endangered in the foreseeable future.  The US Fish and Wildlife Service also maintains a list of species that are candidates or proposed for listing as threatened or endangered.  In California, the state has designated two additional categories:  rare species, and species of special concern.  Collectively, endangered, threatened, rare, special concern species are referred to as special status species.  Special status species may be animals (including birds, fish, and insects), or plants.

Today there are 50 species of plants and animals (26 animal and 22 plant species) that occur in or near San Francisco Bay wetlands that are listed as threatened of endangered under the state and federal endangered species act. In addition to state and federally listed species, the Bay Area is home to 16 fish and wildlife species and 13 plant species associated with wetlands that are candidate or proposed candidate species for federal endangered or threatened status.

Definitions (both federal and State of California definitions) are provided in the glossary.


There are 296 threatened and endangered species in California -- 116 animals and 180 plants.  Marsh birds like the snowy egret, great egret, black crowned night heron, great blue heron and California clapper rail take advantage of nesting habitat in the San Francisco Estuary.  The different types of wetlands provide habitat for different types of endangered species.  Below is a list of different wetland habitats and the special status species typically found at these habitats.

Tidal Mudflat

Tidal Marsh

Seasonal Wetland


Snowy plover
Pacific herring
Marbled godwit
Western sandpiper
Starry flounder
California least tern

Chinook salmon
Dungeness crab
Clapper rail
Salt marsh harvest mouse
Black rail
Ribbed horsemussel

Northern pintail
Long-billed dowitcher
Western pond turtle
Savannah sparrow
California vole
Ruddy duck
Pygmy blue butterfly

Red legged frog
Yellow warbler
California toad
River otter
Pacific treefrog
Alligator lizard
Black-crowned night heron

For a list of threatened and endangered species for the San Francisco Bay Estuary, please refer to the Baylands Habitat Goals Report ( or the San Francisco Bay Joint Venture Restoring the Estuary Report (

References Used:

Baylands Ecosystem Habitat Goals, SF Bay Area Wetlands Ecosystem Goals Project
Turning Salt into Environmental Gold, Save the Bay
Restoring the Estuary: An Implementation Strategy for the San Francisco Bay Joint Venture.  January 2001
Shaw, Samuel P. and C. Gordon Fredine 1956. Wetlands of the United States - their extent and their value to waterfowl and other wildlife. U.S. Department of the Interior, Washington, D.C. Circular 39. Northern Prairie Wildlife Research Center Home Page. (Version 05JAN99).