Body: Small duck, up to 1 pound, 12-14 inches long. White belly and sides with black back and dusky rump. Puffy-appearing head with multicolored iridescence and fan-shaped white patch. Bill short and bluish gray. Feet pinkish. Wings: Mostly black. Coverts and secondaries form large white patch. Voice: Squeaky whistle. In Flight: Small flighty bird. White belly. Puffy head. White head-patch and trailing edge of underwings evident.
