About Aythya valisineria (A.Wilson, 1814)
Canvasback (Aythya valisineria) measures 48 to 56 cm (19 to 22 inches) in length, weighs 862 to 1,588 grams (1.900 to 3.501 pounds), and has a wingspan of 79 to 89 cm (31 to 35 inches). It is the largest species in the genus Aythya, as well as the largest diving duck in North America. Canvasbacks are similar in size to mallards, but have a heavier, more compact body. A sample of 191 males wintering in western New York had an average weight of 1,252 g (2.760 lb), while 54 females from the same location had an average weight of 1,154 g (2.544 lb). This species has a distinctive wedge-shaped head and a long, graceful neck. Adult males (drakes) have a black bill, chestnut red head and neck, black breast, grayish back, black rump, and blackish brown tail. The drake’s sides, back, and belly are white with fine vermiculation that looks like the weave of a canvas, which is how the bird got its common name. The bill is blackish, and the legs and feet are bluish-gray. The iris is bright red in spring, but becomes duller in winter. Adult females (hens) also have a black bill, with a light brown head and neck that grades into a darker brown chest and foreback. Their sides, flanks, and back are grayish brown, and like males, they have a blackish bill and bluish-gray legs and feet. The species’ sloping body profile sets it apart from other ducks.
