Duck

WATERFOWL with short legs, webbed feet and narrow, pointed wings are known as ducks. A few island species are flightless but most are strong fliers and migratory (see MIGRATION). A race of the common eider (Somateria mollissima) of Hudson and James bays is nearly sedentary, even wintering in Hudson Bay. Ducks, geese and swans comprise a family (Anatidae) with 158 living or recently extinct species. Ducks have worldwide distribution, except for polar regions.

Canada's 29 breeding species belong to 4 tribes in one subfamily; 8 other species from this subfamily have occurred in Canada, as have 2 species of whistling duck (sometimes considered in a separate family) and the Labrador duck (Camptorhynchus labradorius), last seen in 1878. Mandarin ducks (Aix galerielata), escaped from captivity, have shown indications of establishing a feral breeding population in coastal BC; successful breeding has not yet been demonstrated.

Description

Bills of mergansers are long and tubular with deeply toothed edges. All other ducks have a flat, wide bill with fine serrations. The bill is swollen into a spoon shape in northern shovelers (Anas clypeata). Male breeding and winter plumage is distinct from that of females and post-breeding males. Plumage is often highly coloured in males, especially in the wood duck (Aix sponsa). An unusual feature of ducks is that all primaries (flight feathers) are moulted together, making the birds temporarily flightless.

Legs of dabbling ducks are centrally placed, allowing easy takeoff and walking; those of diving ducks are placed far back, aiding in diving but impeding walking and necessitating "pattering" along the water surface prior to takeoff.

Nesting

Most ducks are gregarious, gathering in large feeding, moulting and wintering flocks. At early stages of nesting, males in several species are territorial, but pair bonds are temporary and females undertake all incubation and care of young. Female Barrow's goldeneye (Bucephala islandica) and occasionally common goldeneye (B. clangula) are also territorial.

Nests of most species are of grasses and on the ground, often under shrubbery and usually near water. Wood duck, common goldeneye, bufflehead (B. albeola) and the hooded merganser (Lophodytes cucullatus) nest in holes in trees; common and red-breasted mergansers (Mergus merganser and M. serrator respectively) may nest in crevices underground. Mallards (Anas platyrhynchos) sometimes nest in trees or inside buildings. Several marsh-dwelling species have floating nests. The black-headed duck (Heteronetta atricapilla) of South America always lays its eggs in nests of other species; such brood parasitism is frequent but less developed in redheads (Aythya americana) and infrequent in ruddy ducks (Oxyura jamaicensis).

Clutches are usually large, 4-16 eggs in Canadian species. Downy young are active at hatching, swimming within hours. Females guard and brood ducklings but do not feed them.

Range and Habitat

Ducks nest in aquatic habitats ranging from marshes and tundra ponds to fast-flowing mountain streams and large lakes across Canada. Dabbling ducks are most common on the Prairies; seaducks range far into the Arctic. The American black duck (Anas rubripes) is centered in the Maritimes, Québec, and formerly eastern Ontario; most other species are widespread or primarily western.

Barrow's goldeneye and harlequin ducks (Histrionicus histrionicus) breed in disjunct populations on both coasts. The eastern Canadian population of harlequins has declined markedly due to hunting and has been classified by COSEWIC as endangered. The cinnamon teal (Anas cyaoptera), primarily of interior BC and extreme southwestern Alberta, has the most localized range in Canada. The gadwall (Anas strepera), formerly western for the most part, has been increasingly expanding eastward.

Most species gather along the coasts and Great Lakes in winter or fly south. Thermally maintained RESERVOIRS have resulted in increasing numbers of wintering ducks, even on the prairies. Two Eurasian species, the Eurasian widgeon (Anas penelope) and tufted duck (Aythya fuligula), are increasingly wintering in coastal BC and more frequently occuring in inland and eastern areas.

Diet

Most ducks eat a mixture of vegetation and invertebrates; several dabblers sometimes feed on grain crops. Mergansers eat mostly fish.

Relationship with Humans

Mallards and Muscovy ducks (Cairina moschata) are widely domesticated for food; the common eider is semidomesticated in Iceland for down. Ducks are a favourite object of HUNTING.

See also GAME BIRD; ENDANGERED ANIMALS.

Author MARTIN K. MCNICHOLL

Suggested Reading
F.C. Bellrose, Ducks, Geese and Swans of North America (1976); P.A. Johnsgard, Ducks, Geese and Swans of the World (1978); R.S. Palmer, ed, Handbook of North American Birds, Vols 2 and 3 (1976).

Links to Other Sites
Harlequin Duck
A natural history of the Harlequin Duck a small, relatively uncommon sea duck species. From the "Hinterland Who's Who" website.

Wood Duck
See a description of the natural history and typical habitat of the Wood Duck in Canada. From the "Hinterland Who's Who" website. Also includes video clips, summaries of related conservation issues, and educational resources.

Ducks Unlimited Canada
All Ducks Unlimited organizations conserve, restore and manage wetlands and associated habitats for North America’s waterfowl. These habitats also benefit other wildlife and people.

All About Birds
Search this online bird identification guide for information on specific bird species found in North America. Click on the dynamic map of eBird sightings for a magnified view. From the Cornell Lab of Ornithology in the US.

Canadian Biodiversity Website
A great information source for all budding biologists. Learn about biodiversity theory, natural history, and conservation issues. From McGill’s Redpath Museum.

Species at Risk Public Registry
A searchable database of Canadian species at risk. Provides illustrated natural histories of each species as well as information about recovery programs, a glossary, and more. From Environment Canada.

Bird Studies Canada
The website for “Bird Studies Canada,” an organization dedicated to preserving wild birds and their habitats. Search this site for the latest information on bird sightings and populations, checklists and maps, species at risk, and more.

People of a Feather
Watch a trailer for an engrossing film about the world of Inuit on the Belcher Islands in Hudson Bay and their cultural relationship with the eider duck.