Winter Wintering Canvasbacks are found primarily along the Atlantic, Pa- 

 cific, and Gulf coasts of the United States and Mexico, but substantial numbers 

 also winter inland. The Chesapeake Bay is the largest wintering ground, har- 

 boring some 92,000 birds; the next largest concentration, 60,000 birds, winters 

 in San Francisco Bay (Bellrose 1976). Bellrose (1976) summarized winter water- 

 fowl surveys for 1960-1971 and indicated that about half the average North Am- 

 erican winter population of 290,000 wintered along the Atlantic Flyway, most of 

 them just north of North Carolina. The figures provided by Bellrose show that 

 the southeastern states are an important wintering ground for the Canvasback. 

 Twenty percent of the total winter population is found there; 26% of these oc- 

 curred in North Carolina, 6% in South Carolina, a few in Georgia, 13% in Flor- 

 ida, 4% in Alabama, 8% in Mississippi, 26% in Louisiana, and 16% in Texas. 



Figures provided by the 1975 winter waterfowl survey (Goldsberry et al. 

 1980) suggest a somewhat different distribution that can probably be attributed 

 both to annual variation in wintering areas and to incomplete coverage by the 

 survey. Approximately 291,000 birds were found on the January survey, about 

 17% (48,610) of which were in the southeast. North Carolina accounted for 41% 

 of the Canvasbacks occurring in southeastern waters, and Texas harbored another 

 53%. No other state reported more than 1,000 birds. 



Migration Bellrose (1976) summarized migratory pathways of the Canvasback, 

 noting that most Canvasbacks move toward either the Atlantic or Pacific coasts 

 from their breeding grounds and staging areas. Those migrating toward the Ches- 

 apeake Bay move from southeastern Saskatchewan southeast and then east along two 

 paths, one through the Great Lakes area and then to the southeast, and the other 

 from the Mississipi River between Fort Madison and Keokuk due east. Most of the 

 Canvasbacks arriving in the Chesapeake Bay winter there, but a substantial num- 

 ber move south to Currituck Sound in North Carolina. Relatively few continue 

 on south to Florida (Bellrose 1976). 



Other birds from the Fort Madison/Keokuk area move directly south and 

 southeast to Louisiana, Alabama, and Florida. Most of the birds wintering in 

 Texas migrate directly south (Bellrose 1976). 



HABITAT 



Nesting Canvasbacks nest in small, shallow ponds usually less than an 

 acre in size and bordered by cattails, bulrushes, and other emergent vegetation. 

 Most of their feeding, resting, and courting takes place on larger, deeper, per- 

 manent ponds (Trauger and Stoudt 1974 Ln Bellrose 1976). Others may breed in 

 village ponds, farmyard sloughs, large marshes, and potholes (Bellrose 1976, 

 Palmer 1976b). Nests are usually built over water, occasionally on muskrat 

 ( Ondatra zibethica ) houses and seldom on dry land (Palmer 1976b). Authors cit- 

 ed in Bellrose (1976) indicated that cattails are most used for nest sites in 

 prairie potholes and that willows, bulrush, sedges, and phragmites cane are ex- 

 tensively used in other areas. 



Feeding Most feeding on the breeding grounds occurs near the nesting areas 

 on larger, more permanent ponds than those used for nesting (Trauger and Stoudt 

 1974 in Bellrose 1976). Those nesting in a prairie pothole region in southern 



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