Important Bird Areas (IBA) in San Francisco Bay

Richardson Bay was named as one of 148 Important Bird Areas in California in the publication Important Bird Areas of California by Daniel S. Cooper, 2004. Below is information on the program as well as specific information on Richardson Bay .

photo by Kerry Wilcox

What are Important Bird Areas?

California's Important Bird Areas

Where are San Francisco Bay's Important Bird Areas?

Richardson Bay Important Bird Area

Contact Information

What are Important Bird Areas?

Important Bird Areas are sites that provide essential habitat for one or more species of birds. Important Bird Areas have been designated around the world as part of an international global effort. Important Bird Areas include sites for breeding, wintering, and/or migrating birds. These sites may be a few acres or thousands of acres, but usually they are discrete sites that stand out from the surrounding landscape. Important Bird Areas may include public or private lands, or both, and they may be protected or unprotected.

California Important Bird Areas are:

Less than 100,000 acres in extent

Biologically and geographically distinct

Satisfactory in meeting one of the four criteria below.

Four criteria were used in identifying California IBAs:

• More than 10% of California’s or 1% of the global population (breeding and/or wintering) of one or more sensitive bird species are supported by the site
• More than 9 federally or state listed threatened or endangered species are supported by the site
• More than 10,000 shorebirds are possible on a 1-day count
• More than 5000 waterfowl are possible on a 1-day count

California's Important Bird Areas

Audubon California’s Important Bird Area program benefited from hundreds of volunteer hours and involved dozens of technical advisors who provided data and reviewed sites for inclusion as Important Bird Areas. In 2004, Audubon published Important Bird Areas of California by Daniel S. Cooper. This book describes California’s 148 Important Bird Areas and is now being used by local activists, public agencies and conservation groups to guide conservation activities at these sites.

Beginning in May 2006 Audubon California focused on prioritizing Important Bird Areas for conservation action and developing partnerships with Audubon chapters, public agencies, and conservation organizations to help protect and monitor Important Bird Areas.

Audubon California is focusing its conservation work on a number of high priority Important Bird Areas – San Francisco Bay, Salton Sea and the Imperial Valley, Kern River Valley, Southern Orange County among several others

Where are the IBAs in San Francisco Bay ?

The San Francisco Bay Area is a major region of endemism, hosting three recognized races of Song Sparrow, as well as the Saltmarsh Common Yellowthroat and the California Clapper Rail. The wetlands of San Francisco Bay support a half-million shorebirds during migration and winter, and those of the Sacramento-San Joaquin Delta (often included with San Joaquin Valley bioregion) provide the ecological link between the Pacific coast and the Central Valley. Among its millions of wintering waterfowl, the Delta supports most of the world’s wintering population of Tule White-fronted Goose, as well as large numbers of Sandhill Crane and Tundra Swan.

San Francisco Bay is recognized as a Western Hemisphere Shorebird Reserve Network (WHSRN) Site of Hemispheric Importance for shorebirds – the highest possible ranking. http://www.whsrn.org/SanFranciscoBay/index.html

Based on interviews with local experts, it was concluded that nearly every stretch of coastline in north San Francisco Bay (including San Pablo Bay) fit at least one Important Bird Area criteria. Due to the exceptionally intact configuration of the wetlands rimming San Pablo Bay and the obvious exchange of birds around the North Bay, this was identified as a single Important Bird Area, basically extending from the "Marin Baylands" north up the Petaluma and Napa Rivers, and east to Mare Island . Smaller, isolated areas of the Marin shoreline, Corte Madera Marsh and Richardson Bay, were identified as separate Important Bird Areas.

Below is a list of IBAs designated within the waters and
associated habitats of the San Francisco Bay area:

Alameda Naval Air Station

Brooks Island Regional Preserve

Corte Madera Marsh

Eastshore Wetlands

North Richmond Wetlands

Richardson Bay

San Francisco Bay-South

San Pablo Bay Wetlands

Richardson Bay Important Bird Area

Marin County
Nearest town(s): Tiburon, Mill Valley
Size: 2000 – 3000 acres
Sensitive species: 3 (Long-billed Curlew, San Pablo Song Sparrow) (Shuford 1993); San Francisco Clapper Rail
(R. Hinz, K.Wilcox, pers. obs. 2006)
Local Audubon Chapter: Marin

IBA Criteria		Source/Notes
W	> 5000 Waterfowl	5888 waterfowl within Richardson Bay Audubon Sanctuary on 5 January 1999; K. Howard, unpubl. data.

Description: Richardson Bay is located just north of San Francisco in southeastern Marin County in the urbanized middle section of San Francisco Bay across from Berkeley. Much of the shoreline has been filled and rip-rapped, but a few sections are less disturbed. A small area in the northwest, Bothin Marsh, is managed by Marin County Open Space District. This wetland, along with the wetlands of Corte Madera, represents the majority of the tidal marsh habitat of west-central San Francisco Bay. Nine hundred acres of open water are protected as the Richardson Bay Wildlife Sanctuary under the management of the National Audubon Society, which has maintained a small interpretive center and sanctuary since 1958 on 11 acres of coastal scrub, riparian thicket and oak woodland.

Birds: The large numbers of waterfowl during high tide and shorebirds during low tide that find refuge in the sanctuary make it an important link of habitat in an otherwise urbanized portion of San Francisco Bay between the extensive refuges to the north and south. Over 8000 scaup (Greater and Lesser) have been recorded within the Audubon sanctuary alone (M. Sundove, personal communication), although the area normally supports 2,000-4,000 ducks, mainly Scaup, Ruddy Duck, and Bufflehead (M. Sundove, personal communication). Hundreds of shorebirds, especially Western Sandpiper, utilize the exposed mudflats of Bothin Marsh and the greater Richardson Bay daily during migration.

photo by Kerry Wilcox

Conservation issues: The Bay waters under the protection of the Sanctuary are closed to boat traffic from October 1 until March 31 of each winter in order to prevent disturbances to wintering and migrating waterbirds. Several species of waterfowl that were once more common on the Bay such as Canvasback and Surf Scoter have not been seen as frequently as in past years, and one species, Brant, has rarely been seen at all. The upland portions of this Important Bird Area are extensively invaded with exotic vegetation (e.g. French Broom, exotic plum trees, Cotoneaster, European annual grasses, etc.). Currently the Richardson Bay Sanctuary and Center is conducting experimental reintroductions of native eelgrass and oysters within Bay waters.

Contact Information

Richardson Bay IBA contact:

, Sanctuary Manager

Richardson Bay Audubon Center & Sanctuary

376 Greenwood Beach Rd

Tiburon , CA 94920

Ph (415) 388-2524 x101,

Fax (415) 388-0717E

 

Important Bird Areas Program contact:

Andrea Jones -- Important Bird Areas Program Coordinator

Audubon California

601 Embarcadero, Suite 14

Morro Bay , CA 93442

Phone/fax: 805-772-1995

http://ca.audubon.org/iba

 

Mike Perlmutter -- Bay Area Conservation Coordinator

Audubon California

4225 Hollis Street

Emeryville, CA 94608

Tel: 510-601-1866 ext. 7

Fax: 510-601-1954