The lowlands on the north side of the Seward Peninsula produce fall flights of sea ducks that average 49,200 oldsquaws (Clangula hyemalis), 51,000 eiders (mostly common eiders, Somateria mollissima), and 26,700 scoters (mostly black scoters, Melanitta nigra) (King and Lensink 1971). Small populations of black brant and emperor geese breed in what outwardly appears to be excellent habitat, and King and Lensink (1971) speculated that subsistence hunting by local Eskimos is responsible for suppressing these populations.
Bering Sea
The largest concentration of nesting seabirds in the Bering Sea and perhaps in the entire North Pacific is that on St. George Island. Colonies that rank somewhere below that at St. George are along the coast from Cape Newenham to Cape Peirce, in the Walrus Islands (Round, High, Crooked, and Summit islands, The Twins, and Black Rock), at Cape Mohican on Nunivak Island, St. Matthew Island, Southwest Cape of St. Lawrence Island, and King Island.
The Pribilofs have the unique distinction of being the primary nesting site of red-legged kittiwakes (Rissa brevirostris). They are also interesting from the zoogeographic standpoint in that they are the northernmost stronghold of red-faced cormorants (Phalacrocorax urile); guillemots are conspicuous by their absence, and larid gulls are conspicuously scarce nesters.
St. Matthew Island and associated Hall and Pinnacle islands, and all but Walrus Island of the Pribilofs, are sites of nesting northern fulmars (Fulmarus glacialis). Nesting fork-tailed or Leach's storm-petrels (Oceanodroma furcata and O. leucorhoa) have been found nowhere in this region, although both are commonly observed at sea and both nest throughout the Aleutians.
Most colony sites identified in Fig. 2 are dominated by common or thick-billed murres (or both) and black-legged kittiwakes. Glaucous gulls (generally north of the Yukon-Kuskokwim delta), glaucous-winged gulls (Larus glaucescens) (generally to the south of the delta), and pelagic cormorants occupy almost every rocky prominence along the entire coast (most of these sites are not shown in Figs. 2 and 3). Double-crested cormorants (Phalacrocorax auritus) nest at a few island and inland locations in the Bristol Bay area. The small auklets are largely restricted to islands in the Bering Sea; the parakeet auklet is the only one occasionally found in mainland colonies.
The marine birds of the Yukon-Kuskokwim delta lowlands, although largely uncounted, in their aggregate probably exceed the numbers at any individual site identified in Fig. 2. This is not particularly surprising since the delta has nearly 70,000 km2 of habitat (King and Lensink 1971) in contrast to the generally small parcels of habitat occupied at the sea-cliff and island sites.
King and Lensink (1971) estimated that fall flights of sea ducks originating on the delta averaged 292,300 oldsquaws, 51,000 eiders (mostly common and spectacled eiders with lesser numbers of Steller's eiders, Polysticta stelleri), and 157,000 scoters (primarily black scoters). They also estimated that half of the 150,000 black brant and most of the 150,000 emperor geese in Alaska's fall flight originate there. Although no counts have been made, we believe that the delta's lowlands support easily more than half of Alaska's nesting dunlins, black turnstones (Arenaria melanocephala), rock sandpipers (Calidris ptilocnemis), western sandpipers, and substantial percentages of red phalaropes (Phalaropus fulicarius), northern phalaropes (Lobipes lobatus), and red-throated loons.
The north side of the Alaska Peninsula (including the wetlands, uplands, and estuaries) is perhaps more important to marine birds as a staging, feeding, and resting area than as a nesting habitat. The importance of Izembek Lagoon to black brant and emperor geese during fall and spring is a classic example. King and Lensink (1971) estimated that the fall flight of sea ducks originating from the Peninsula averages 53,400 oldsquaws, 1,700 eiders, and 74,400 scoters. Breeding geese are scarce throughout the area.