SYNOPSIS OF PRESENT DISTRIBUTION AND ABUNDANCE 



Breeding The Lesser Scaup nests only in North America. Most breed from 

 north-central Alaska south to northeastern Idaho and northwestern Wyoming, 

 southeast to northeastern Manitoba, thence south to northwestern Minnesota and 

 northeastern North Dakota. Other small or local populations breed or have bred 

 from northeastern California and eastern Oregon east across the northern Great 

 Plains to Ohio. Breeding has also been reported on eastern James Bay in Quebec 

 (Palmer 1976b). 



Precise numbers of breeding Lesser Scaup are unavailable because the U.S. 

 Fish and Wildlife Service does not distinguish between Greater and Lesser Scaup 

 in surveys of the breeding grounds. According to Bellrose (1976), the total 

 breeding population of both species of scaup is larger than that for any other 

 duck except the Mallard. Estimated total breeding populations for these two 

 species varied from 5,100,000 to 9,100,000 during 1955-75, with a mean of 

 6,900,000. The largest numbers of breeding birds are found in the open boreal 

 forest of Canada (1,700,000 birds), in the closed boreal forest to the east 

 (1,900,000), and in interior Alaska (600,000) (Bellrose 1976). The 1976 breed- 

 ing ground survey (Larned et al. 1980) listed a total of about 6,900,000 breed- 

 ing scaup. 



Winter Lesser Scaup winter both inland and along the coasts of North Amer- 

 ica, with most wintering in the eastern half of the continent (Bellrose 1976). 

 The southern limits of the wintering range are in the Caribbean and northern 

 South America (Palmer 1976b). This scaup is more abundant along the coasts but 

 is often found on fresh or brackish waters within these areas. 



Bellrose (1976) estimated that 1,454,000 Lesser Scaup were wintering in 

 the United States in the late 1960's, in addition to another 297,000 in Mexico. 

 Smaller numbers winter in Guatemala, and about 7,500 winter in the West Indies, 

 mostly in Cuba. Figures provided by Bellrose suggest that nearly 85% of the 

 total wintering population is found in southeastern waters and along the coast 

 of Mexico. Only a small proportion (ca. 10%) of those wintering within the 

 United States are found in the western half of the continent. Most of the rest 

 of the U.S. winter population occurs along the lower Mississippi drainage and 

 along the central and northeastern Atlantic Seaboard (Johnsgard 1975). Major 

 concentrations are found along the coast of Texas and Louisiana, along the cen- 

 tral Gulf and Atlantic coasts of Florida, and off Georgia (Bellrose 1976, Map 

 22). Data from the 1975 winter survey (Goldsberry et al. 1980), while incom- 

 plete, suggest a wintering population in the United States and Mexico of no 

 less than 983,000 that year. This decrease from the figures provided for early 

 counts by Bellrose is probably more apparent than real, since several areas of 

 concentration for this species in the Mississippi Flyway went unsurveyed . 



Migration Most migrating Lesser Scaup move southeast from their primary 

 breeding grounds in the northwestern portion of North America. The pathway 

 used by the largest number of birds extends south-southeast from there to Lakes 

 Winnepegosis and Manitoba, northwestern Minnesota, and to the Mississippi River 

 between Burlington and Keokuk, Iowa (Bellrose 1976). Most Lesser Scaup fly 

 from the latter area south to the Gulf, but substantial numbers continue south- 

 east to the Gulf coast of Florida. Other important routes follow the coastlines 



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