Gadwall

Anas strepera

46-56cm

Appearance

At first glance this bird may seem undistinguishable, though with close inspection, the male bird's seemingly grey plumage is intricate and vermiculate. This is a smaller bird than the Mallard, and both sexes have a bright white speculum when in flight; when swimming it looks like a patch on their side. The appearance of the sexes differs; the male's inner wing is chestnut-coloured, his stern, rear and tail are all black and the middle of his belly is white. The bill is grey-black and his legs are yellow. The female's plumage is greyer than the male's, her belly whiter, and the sides of her bill are orange-tinged. Juveniles look like female adults.

Habitat

In Britain, lowland wetlands in central, southern and eastern England are preferred; the Gadwall has also recently colonised gravel workings and the edges of reservoirs. Breeding takes place on the vegetation of lowland lakes or rivers without strong currents. During the winter it may expand its habitat to large bodies of freshwater such as estuaries.

Character

Has a habit of following other birds such as Coots and Mute Swans, and travels in small flocks in winter. Gadwall females may nest within 5m of each other but they don't nest in colonies.

Food

Primarily a vegetarian bird, the Gadwall feeds on plant material on the water's surface, or it up-ends if it needs to search lower. The most common foods include stems, leaves and the seeds of pondweeds, sedges, rushes, grasses and stonewort. Insects, water snails and small amphibians may also be eaten, though it is suspected this is incidental rather than intentional.

Breeding

Builds nests on the ground, often on small islands and usually in thick vegetation close to water. Nests may also be in less sheltered places near to terns or gulls, because these birds help Gadwalls stay safe from predators. The female lays 7-9 eggs which she incubates for 24 days – the male deserts during this period. Hatchlings can feed themselves but the female broods them while they're small, and they fly after 45 days, marking their independence.

Population

The UK population is biggest in the south and east of England. The birds can be found in all seasons but they're more prevalent in winter, when migrations arrive from Iceland and northern and eastern Europe. Some British and Irish birds appear to stay all year round, and others travel to Europe in autumn. Numbers are on the rise; over 25 0000 individuals spend winter in Britain and Ireland.

Observation Tips

The black stern of the male is a clear identifier, as well as the white speculum of both sexes. There's a fair chance of spotting Gadwall flocks in the region between November and March.

Voice

Predominately a silent bird, the male has a low, raspy croak, usually given in flight. Female has a high-pitched quack.
Barnacle Goose Branta leucopsis Bean Goose Anser fabalis Bewick's Swan Cygnus columbianus Brent Goose Branta bernicla Canada Goose Branta canadensis Common Scoter Melanitta nigra Egyptian Goose Alopochen aegyptiaca Eider Somateria mollissima Gadwall Anas strepera Garganey Anas querquedula Goldeneye Bucephala clangula Goosander Mergus merganser Greylag Goose Anser anser Long-tailed Duck Clangula hyemalis Mallard Anas platyrhynchos Mandarin Aix galericulata Mute Swan Cygnus olor Pink-footed Goose Anser brachyrhynchus Pintail Anus acuta Pochard Aythya ferina Quail Coturnix coturnix Red Grouse Lagopus lagopus Red-breasted Merganser Mergus serrator Ruddy Duck Oxyura jamaicensis Scaup Aythya marila Shelduck Tadorna tadorna Shoveler Anas clypeata Smew Mergus albellus Teal Anas crecca Tufted Duck Aythya fuligula Velvet Scoter Melanitta fusca White-fronted Goose Anser albifrons Whooper Swan Cygnus cygnus Wigeon Anas penelope