Bair Island (including Bird Island)
Map SatelliteA portion of Bair Island is included in the South San Francisco Bay National Wildlife Refuge (see also Life Refuge, Greco and Bair Island Units) but important portions of the habitat were not included.
Mudflats and salt ponds cover much of the area not in the Refuge; however, there are salt marshes along the periphery of Bair Island and covering Bird Island. In the salt marshes dominant vegetation includes pickleweed, Salicornia virginica, salt grass, Distichlis spicata, and cord grass, Spartina foliosa.
Three endangered species are found on these islands, the salt-marsh harvest mouse, Reithrodontomys raviventris, California clapper rail, Rallus longirostris obsoletus, and the California least tern, Sterna albifrons browni. The colony of tern on Bair Island has only recently, probably in 1969, been established and is the northernmost in the State, representing a considerable extension from the 1943 records showing Moss Landing as the northernmost. Additionally, the islands support one of the larger heron and egret rookeries in the Bay Area. Numerous migratory waterfowl and shorebirds may be observed on the mudflats and open water during the fall through spring months.
Harbor seals, Phoca vitulina, are frequently sighted in the area.
Integrity: A transmission line bisects Bair Island and levees have been constructed for the salt ponds. The channel to the Port of Redwood City passes close to Bair Island. Bird Island is separated from Foster City by Belmont Slough. There is considerable boating offshore but the shoal waters tend to protect the islands.
Use: Research, educational, observational.
Ref: Gill, Robert, 1971. South San Francisco Bay Breeding Bird Survey 1971. California Department of Fish and Game, Sacramento.
December 1975
Inventory of California Natural Areas
Revision © 2009 Steven Louis Hartman