arctic from Scandinavia to Kamchatka. 



Using aerial and ground surveys performed by various agencies, Bellrose 

 (1976) gave an estimate of ca. 675,000 for the North American breeding popula- 

 tion of White-winged Scoters, but he indicated that this figure was probably 

 too large. He also noted declines in breeding populations in some portions of 

 the North American range; surveys of the breeding grounds in 1976 indicated de- 

 clines from the 1966-75 mean for scoter species breeding in northern Alberta 

 and the Northwest Territories (-14%), in northern Saskatchewan and northern 

 Manitoba (-24%), and in southern Saskatchewan (-70%). Populations in southern 

 Alberta and Manitoba increased markedly from the ten-year mean (Larned et al . 

 1980). Old World breeding populations are poorly known; the population breed- 

 ing in the western Palearctic is apparently much smaller than that in North 

 America and is apparently decreasing in much of its range. 



Winter North American White-winged Scoters winter along the Pacific coast 

 from the Aleutians and southern coastal Alaska to Baja California, and along 

 the Atlantic coast from the Gulf of St. Lawrence to South Carolina. Some also 

 winter in the Great Lakes States, and a few (Map 27) along the Gulf coast (AOU 

 1957, Palmer 1976b). Bellrose (1976) estimated that about 56,000 White-winged 

 Scoters wintered along the Atlantic coast on the average during U.S. Fish and 

 Wildlife Service inventories (1966-73). Nearly 70% of all scoters wintering 

 along the Atlantic coast are found between Long Island Sound and the Chesapeake 

 Bay region; areas of maximum concentration vary from species to species, however, 

 and White-winged Scoters are most abundant from Maine to New Jersey (Bellrose 

 1976). 



On the Pacific coast of North America the largest wintering populations of 

 White-winged Scoters are found in the Aleutian Islands (perhaps 250,000 birds), 

 and from southeast Alaska to California (Bellrose 1976). The 1976 winter water- 

 fowl survey of the contiguous United States (Larned et al . 1980) listed winter- 

 ing populations of 96,800 scoters in the Pacific Flyway and 59,800 in the Atlan- 

 tic Flyway; another 10,500 were reported from the west coast of Mexico. 



Cramp et al. (1977) considered the White-winged Scoter the least numerous 

 sea-duck wintering in the western Palearctic and cited an estimate of perhaps 

 150,000-200,000 birds. 



Migration Migration routes and chronology are detailed by Bellrose (1976). 

 In general, birds migrate east or west towards the coast and then along the 

 coastline to their wintering areas. Band recoveries suggest that the farther 

 north and east the birds breed, the more likely they are to migrate towards the 

 Atlantic coast, and the farther south and west they breed, the more likely that 

 migration is to the Pacific coast (Bellrose 1976). 



The northward movement of White-winged Scoters wintering along the Atlan- 

 tic coast begins as early as March; migration occurs mostly in October and Nov- 

 ember (Palmer 1976b). Palmer (1976b) gave additional information on differences 

 in migration between birds of different age and sex and remarked that data from 

 Old World populations suggested similar patterns of movement there. 



380 



