The Gadwall is 46-56 cm (18-22 in) long with a 78-90 cm (31-35 in) wingspan. The male is slightly larger than the female, weighing on average 990 g against her 850 g. The breeding male is patterned grey, with a black rear end, light chestnut wings, and a brilliant white speculum. In non-breeding plumage, the drake looks more like the female, but retains the male wing pattern, and is usually greyer above and has less orange on the bill.The female is light brown, with plumage much like a female Mallard. It can be distinguished from that species by the dark orange-edged bill, smaller size, the white speculum, and white belly.
Habitat and Distribution
The Gadwall breeds in the northern Europe and Asia, and central North America. In North America, it breeds along the Saint Lawrence River, through the Great Lakes, Alberta, Saskatchewan, the Dakotas, south to Kansas, west to California, and along coastal Pacific Canada and southern coastal Alaska. It is strongly migratory, and winters farther south from coastal Alaska, south into Central America, and east into Idaho, Kansas, Ohio, Virginia. It is a bird of open wetlands, wet grassland or marshes with dense fringing vegetation
The Gadwall feeds by dabbling for plant food with head submerged. The young birds are fed insects at first; adults also eat some molluscs and insects during the nesting season.
It nests on the ground, often some distance from water.
Calls and Songs
Females give a call similar to the quack of a female Mallard but higher-pitched, transcribed as gag-ag-ag-ag. Males give a grunt, transcribed as nheck, and a whistle.