Breeding birds: 1,200 pairs
Wintering birds: 25,000 birds
Family: Ducks, geese & swans
Adult male gadwalls in breeding plumage has a grey-brown mantle, back, and flanks that are vermiculated black and white. The upper breast is black with a scaled pattern, the lower breast and belly are white, and the rump is black. There is a while speculum on the wings and the wing coverts are chestnut and black. The underwing is white with grey flight feathers. The tale is pale grey with a black uppertail and undertail coverts.
Gadwalls have a grey-brown head with a cinnamon was on the forehead and chin. The bill is slate-grey, the eyes are dark brown, and the legs and webbed feet are orange-yellow.
Female gadwalls have mottled brown and buff plumage with a smaller white speculum, and the flanks are darker. The chin and upper breast are paler and the bill is yellow with dark spots.
Out of breeding plumage, male gadwalls resemble the female and the bill has a dark culmen with orange sides, and the legs and feet are duller.
Juveniles are similar to the female but darker with more streaks. Young females sometimes have no chestnut on the upperwing.
Gadwalls breed from April to July. The nest site is chosen and built by the female while the male stands guard. It is a scrape in the soil lined with leaves, grass, and twigs, and lined with feathers she plucks from her own body. Sometimes more than two gadwalls may use the same nest.
Gadwalls lay 7-13 cream-coloured eggs which are incubated by the female alone for 24-27 days. Chicks are precocial and are covered in light brown and creamy-buff down. They are led to water by the female where they are able to feed themselves. They perform their first flight 48-59 days after hatching.
Gadwalls feed mainly on aquatic vegetation, and invertebrates, such as insects, crustaceans, amphibians, and fish, dabbling and dipping. It will also forage on land for grain and in woodland for acorns.
Gadwalls can be seen all year round in the UK. The best time to spot them is during the winter when resident birds are joined by birds from the continent. They are found mainly in the Midlands, south-east England, eastern central Scotland, south-east Wales, and the south-east of Ireland.
Look out for them in gravel pits, lakes, reservoirs, coastal wetlands, and estuaries.
A dwarf subspecies of gadwall, Coues’s gadwall, which was found on Teraina, a coral atoll in the Pacific Ocean, went extinct in 1874 due to overhunting by settlers.