This file displays the distribution and average seasonal abundance of diving ducks at the South Bay salt ponds. Birds were identified and counted monthly from January 2003 through August 2005 within 3 hours of high tide. Data presented herein are average monthly counts per season: winter (December-February), spring (March-May), summer (June-August), and fall (September-November). We assigned species to foraging guilds, groups of species with similar habitat requirements. These included: 1) dabbling ducks (e.g. northern shovelers Anas clypeata); 2) diving ducks (e.g. ruddy ducks Oxyura jaimaicensis); 3) eared grebes (e.g. Podiceps nigricollis); 4) piscivores (e.g. double-crested cormorants Phalacrocorax auritis); 5) gulls (e.g. ring-billed gulls Larus delawarensis); 6) herons and egrets (e.g. great egrets Ardea alba); 7) medium shorebirds (e.g. marbled godwits Limosa fedoa); 8) phalaropes - (e.g. Wilson's phalaropes Phalaropus tricolor); and 9) small shorebirds (e.g. western sandpipers Calidris mauri). The diving duck guild included the following species: bufflehead, canvasback, common goldeneye, common loon, redhead, ring-necked duck, ruddy duck, scaup sp. (greater and lesser), surf scoter, and white-winged scoter.