The long sloping shape of the bills of these ducks in the waters off of Occoquan Bay National Wildlife Refuge indicated to me that they are Canvasbacks ducks (Aythya valisineria). Most of the time I rely primarily on colors when trying to identify birds, but during the non-breeding season, many ducks share the same subdued colors, especially when viewed from a distance. This was a rare case when a single distinctive characteristic—in this case the bill—was enough for me to identify the birds with a reasonable degree of confidence.
According to Wikipedia, the duck’s common name is based on early European inhabitants of North America’s assertion that its back was a canvas-like color. In other languages it is just a white-backed duck; for example in French, morillon à dos blanc, or in Spanish, pato lomo blanco.
© Michael Q. Powell. All rights reserved.
