Wild muscovies are mostly black, but the commonest domestic variety is white, with knobby, naked red skin around the face and bill. It and the turkey are the only domestic birds that originated in the Americas. The wood duck is classified as Aix sponsa, the spectacled eider as Somateria fischeri, and the blue-winged teal as Anas discors. The mallard is classified as Anas platyrhynchos and the muscovy duck as Cairina moschata. Gadwall Gadwall, common name for a large, mainly freshwater duck, native to North America, Europe, North Africa, and parts of Asia.
Males have brownish heads, grayish bodies, dark bills, and yellow feet.
The females are a mottled brown. Both sexes of the gadwall have a white speculum, or wing patch. Although normally a surface-feeding bird and therefore almost entirely herbivorous, the gadwall often dives for its food underwater. In North America it nests mainly in western and central regions, although it has spread east in recent years, and winters principally in the lower Mississippi Valley and Mexico. Teal Common name applied to certain small, freshwater ducks.