Courtesy Kenn Kaufman
Canvasbacks breed exclusively in North America from the northern Great Plains into eastern Oregon, then north through the Canadian prairies into the interior of Alaska. Wintering Canvasbacks range along the mid-Atlantic states south through Georgia and then westward into Arizona. They winter as far north as Missouri and as far south as central Mexico. Along the west coast, this diving duck winters from Puget Sound through Baja California. During migration, the Canvasback can be found across most of the United States.
A legend for the range map to the right can be found here
Canvasbacks breed in deep water marshes, ponds, prairie potholes, and lakes with emergent plants like bulrushes, reeds, and cattails. During migration, this diving duck uses a variety of fresh and salt water lagoons, impoundments, river bends, backwaters, estuaries, deep lakes, and bays with plenty of submerged plants and mollusks for food. Wintering Canvasbacks use similar habitats, but tend to congregate coastally.
A heavy body and large feet help keep the Canvasback perpendicular as it forages in the mud beneath still bodies of water. Diving from nine to 30 feet, this duck catches and consumes large amounts of clams, mussels, snails, and insects. Canvasbacks also dig in submerged mud with their feet, eat the succulent parts of aquatic plants like wild celery and sago pond weed, and pick items from the water’s surface or from the air. During the breeding season, females tend to eat more animal prey.
Canvasbacks begin forming monogamous pairs during migration. Several males attend one female and use various displays and vocalizations that include clucks, coos, murmurs, and coughs. Females select mates and choose nesting sites near their own hatching places. Tucked among young plants just above the water, the female builds a mound of dry plants arranged loosely and lined with fine vegetation and down. The female lays about eight greenish eggs. When other ducks (like Canvasbacks and Redheads) lay eggs in her nest, the overall clutch size remains the same but the host’s clutch size may be reduced by as much as 30%. This “brood parasitism” often causes a nest to be abandoned. When water levels drop, predation by foxes and raccoons also becomes high, and an entire breeding season’s worth of young can be lost within a vast breeding range.
Incubation lasts nearly four weeks, and the males guard their chicks against predators and other ducks for about two weeks, before forming flocks and beginning their migration. Canvasback chicks emerge ready to preen, swim, and forage. Females lead chicks to food and safety, but do not feed them. Hens depart after three to seven weeks, depending on the weather and the lateness of the season. Young Canvasbacks fledge in about 62 days.
In flocks of ten to 50, Canvasbacks migrate in V-formation and use all four North American flyways along traditional short to medium-length routes. Fall migrants sort themselves by age and sex, departing as early as mid-August and arriving as late as the end of November. Spring migrants fly in mixed-sex flocks in order to pair up, departing southern sanctuaries as early as February and arriving at northern locations as the ice melts in May.