The canvasback breeds from the upper midwest into Canada and southern Alaska and winters over another large area, ranging from the coasts of British Columbia and Massachusetts to Mexico and Central America.
This duck likes freshwater marshes, but may also breed in areas of the plains that boast large potholes that can hold water for a long period of time. Winters are often spent on or near large lakes, bays, or estuaries.
Because of the draining of marshes and pot holes, the number of canvasbacks has declined sharply in recent years.
The adult male canvasback is one of the largest of the diving ducks, reaching a weight of about 3 pounds.
The bird's name comes from the delicate, wavy pattern of lines and dots over a pale gray and white background, resembling canvas. The male, known as a drake, has a rust-colored head and neck and a black breast during breeding season. In the off season, he closely resembles the female, which has a tan head.
The wedge-shaped bill and bright red eyes are other distinguishing features.
During the morning and evening, the canvasback feeds by diving to the water bottom in search of various plants, insects, small fish, and molluscs.
Its favorite food is wild celery, a freshwater plant whose scientific name is Valisneria americana. That's where the canvasback's name, Aythya valisineria, comes from. (The "Aythya" part is from the Greek for "seabird.")
While feeding, canvasbacks gather in large rafts, often including hundreds of birds. Between feeding times, they rest on the water surface, tucking their bills beneath their back feathers.
A canvasback becomes sexually mature during the spring or summer of its first year, when the female builds a large nest, well concealed among rushes or reeds in shallow water.
A clutch of seven to ten eggs is laid in mid-May and the young birds hatch out after 23 to 29 days of incubation.
The time of migration varies a lot, depending on the climate in which the bird nests. Migration may begin as early as October or late as December, when canvasbacks head south in large formations with the typical V shape. They can travel at speeds of up to 72 miles an hour.