Waterbird migration near the Yukon and Alaskan coast of the Beaufort Sea: I. Timing, routes and numbers in spring. Arctic

ABSTRACT. Westward moult migrations of seaducks were studied in the summers of 1972 and 1975 (northern Yukon) and 1977-78 (west of Prudhoe Bay, Alaska). Methods used were visual observations from the coast, aerial surveys, and (in 1975) DEW radar. Many male Oldsquaws (Clangula hyemalis) fly west near the north coast of Alaska in early July. Most seem to travel only a short distance; tens of thousands subsequently moult in various lagoons along northern Alaska. Few of the male eiders (Somareria spp.) that leave the Beaufort Sea in summer travel west along the coast past the two study areas. Instead, the main route may be seaward of the barrier islands until the eiders approach Point Barrow. In late June and July, several thousand male Surf Scoters (Melanitta perspicillata) fly west near the Yukon and Alaskan coast to moulting areas in lagoons. This flight, unlike moult migrations of most scoters, is not directed toward the wintering areas