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Ecology of Blue-winged Teal Wintering in the Neotropics

Jorge Eduardo Botero

出版	University of Wisconsin--Madison, 1992
URL	http://books.google.com.hk/books?id=OplpAAAAMAAJ&hl=&source=gbs_api

註釋

More than 30 species of North American waterfowl winter in the Neotropics, with distributions that extend south of the United States into Mexico, Central America, South America, or the Caribbean islands. Leopold (1959) suggested that 9-17% of the total North American waterfowl population crosses the U.S.-Mexico border during migration. Saunders and Saunders (1981) reported sizable numbers of northern shoveler (Anas clypeata), gadwall (A. strepera), northern pintail (A.acuta), green-winged (A. crecca), and redheads (Aythya americana)wintering in Mexico. Bellrose (1980) suggested that the majority of black brant (Branta bernicla), blue-winged teal (Anas discors), and cinnamon teal (A. cyanoptera) winter south of the United States.