San Francisco Estuary Midwinter Waterfowl Survey: 2012 Survey Results and Trend Analysis (1981-2012)

The SF Estuary had a large proportion of the Lower Pacific Flyway count for diving ducks (tribes Aythyini, Mergini and Oxyurini): 60% for greater and lesser scaup, 54% for scoter spp., 51% for canvasback, 36% for ruddy duck and 32% for bufflehead. The Estuary is currently a relatively minor wintering area for dabbling ducks (tribe Anatini) and American coots in the Lower Pacific Flyway. The North Bay and South Bay salt production ponds and managed ponds(hereafter ‘North Bay Ponds’ and ‘South Bay Ponds’, respectively) had 55% of the waterfowl and coots counted in the SF Estuary in 2012, while the North Bay Open Bay accounted for 28%. Aside from the open bay areas, Don Edwards San Francisco Bay National Wildlife Refuge (NWR) had the highest count of waterfowl/coots observed in the Estuary, followed by NapaSonoma Marshes Wildlife Management Area and San Pablo Bay National Wildlife Refuge.