Canvasback

Did you know

Canvasbacks are a large diving duck. Breeding males have a gracefully sloped black bill, russet coloured head and canvas-white back, for which the species is named. Hens are coloured to blend with their surroundings while on the nest, and have a reddish-brown head, neck and chest, and a mottled light brown back.

Common name: Canvasbacks
Scientific name: Aythya valisineria
Diet: Omnivorous
Average life span: 10 years
Length: 48-56 cm
Weight: 862-1588 g

Food & Habitat

Canvasbacks inhabit lakes, ponds, rivers, potholes, woodland pools, and surrounding uplands.

They are physically specialized to consume subterranean plant parts and benthic invertebrates, and procure a great deal of their food by rooting through wetland bottoms with their bills.

Breeding & Population

Canvasbacks begin to pair during their return to breeding grounds in the spring. Drakes perform a number of impressive courtship displays during the breeding season. The hen selects the nest site and typically uses the same home range each year. The floating nest is constructed using vegetation and consists of a platform of interwoven plant material often in dense vegetation. The hen lays one egg a day, producing an average clutch of eight or nine eggs. In reaction to periods of extreme drought, the canvasback delays breeding or defers breeding altogether.

Canvasbacks breed from Alaska through the Yukon and western edge of the Northwest Territories to the parklands and mixed prairie of central North America.

Migration

Canvasbacks winter along three coasts, principally from San Pablo Bay along the Pacific, to coastal Louisiana, to the Chesapeake Bay on the Atlantic. Inland, Catahoula Lake in Louisiana has recently hosted the world’s largest single aggregation (sometimes > 70,000) of wintering canvasbacks.

Interesting facts

• Canvasbacks are accomplished athletes. In the air, they are capable of speeds of more than 100 km/hr, and in the water, they can dive to depths exceeding 5 metres, although they mostly feed in shallower places.
• The canvasback’s Latin name Aythya valisineria is derived from the Latin for wild celery, one of their favourite foods in the eastern portion of their range.
• Female redheads find canvasbacks to be attractive surrogate mothers for their young. These hens lay their eggs in the nest of a female canvasback that has already initiated her own nest. Even canvasback hens sometimes will lay eggs in the nest of another canvasback. This act is termed ‘nest parasitism’ and it has a number of negative effects on the host.