Canvasbacks are North America ducks with high forehead and elongated bill. With an unusual head profile their diet is of wild celery buds, that is why their specific Latin name valisineria. Their vernacular name is derived from the pale-gray back and white sides of drakes, that are delicately dotted and lined in wavelike patterns, resembling canvas fabric.
Generally silent except in courtship, the croaks, growls, peeps and soft cooing, dove-like notes of Canvasback drakes are distinctive. Females merely quack harshly, but are also given to low, guttural purring. Pairs may nest on small farm ponds and even along major highways. The beating wings of large flocks generate aloud swishing sounds. They often fly high in small irregular flocks and occasional large V-formations.
Swimming low in shallower waters, the ducks dive quickly. Their long narrow bill is put to dig up aquatic tubers, root stalks and wild celery. Large quantities of seeds especially wild rice are gleaned from bottom ooze and mud. Food is sometimes poached from foraging swans. Courtship consists of prolonged bouts of aquatic and aerial displays, including exhilarating airbone chases. Nesting pairs seek shallow marshes and swamps in prairie country with abundant floating and emergent vegetation with nearby areas of open water. Nests can be partly floating in thick beds of emergent vegetation, and females often add material to raise the height of the nest.
Their spring migration starts as early as February and is underway by March. They are late-fall migrants and sometimes they do not move south until October or even November.