RING-NECKED DUCK 

 (Aythya collarls) 



[FR: Morillon a collier, GE: Halsringente , NW: Ringand, Halsringand, SP: Pato 

 de collar, Pato negro, Pato del medio cavezon] 



GENERAL DISTRIBUTION 



The Ring-necked Duck breeds from the Mackenzie District and British Colum- 

 bia east across Canada to Newfoundland and Nova Scotia, and as far south as 

 northeastern Washington, northern North Dakota, Minnesota, Wisconsin, Michigan, 

 New York, Vermont, Maine, and Massachusetts (Mendall 1938, Chandler 1953, AOU 

 1957). Recent northward extension of the breeding range into Labrador has also 

 been noted (Gillespie and Wetmore 1974). To the south of this general breeding 

 distribution, local irregular breeding has been reported from Oregon, Califor- 

 nia, Nevada, Montana, Colorado, Nebraska, South Dakota, Illinois, Indiana, and 

 Pennsylvania (AOU 1957, Mendall 1958). The principal breeding ground is the 

 closed boreal forest of northwestern Canada (Bellrose 1976). 



In winter, the Ring-necked Duck can be found from Massachusetts southward 

 along the Atlantic coast to Florida, the West Indies, Gulf coast states, and 

 Mexico (AOU 1957, Bond 1971). In the southeast, it may occur inland as far as 

 Tennessee and Arkansas (Johnsgard 1975). Along the Pacific coast, these ducks 

 winter from southern British Columbia to Baja California, in most of Mexico, 

 and in Central America as far south as Panama (AOU 1957, Mendall 1958). 



Ring-necked Ducks winter along the Pacific coast from British Columbia 

 south to Baja California, in Mexico and Central America to Guatemala, and along 

 the Atlantic coast (Map 20) from Massachusetts south to Florida, the West In- 

 dies, the Gulf coast states, Mexico, and Central America (AOU 1957, Mendall 

 1958). January waterfowl inventories indicate that between 240,000 and 300,000 

 Ring-necked Ducks winter in North America. Over half of the birds in the At- 

 lantic Flyway winter in Florida (Bellrose 1976). Large concentrations have 

 also been noted in Cuba (15,000) and in the Dominican Republic (5,500) (Crissey 

 in Bellrose 1976). Two-thirds of the birds wintering in the Mississippi Flyway 

 occur in Louisiana (about 73,000), and slightly over 10,000 Ring-necked Ducks 

 winter from east Texas to Yucatan on the Gulf coast. 



SUSCEPTIBILITY TO OIL POLLUTION 



Three Ring-necked Ducks were among more than 3,200 oiled dead birds found 

 after a spill in San Francisco Bay, California, in 1971 (Smail et al. 1972). 

 Because of its preference for fresh water, the Ring-necked Duck is much less 

 vulnerable to marine oiling than other diving ducks. 



284 



