Redhead (bird) blue bill during the breeding season. The redhead is in the family Anatidae (ducks, swans, geese) and genus "Aythya" (diving ducks). There are currently no described subspecies of the redhead. The redhead and the common pochard form a sister group which itself is sister to the canvasback. This group is then sister to the monophyletic group consisting of the white-eyes (hardhead, Madagascar pochard, and the sister species ferruginous duck and baer's pochard) and scaups (New Zealand scaup, ring-necked duck, tufted duck, greater scaup, lesser scaup). The redhead is a pochard, a diving duck specially adapted to foraging underwater. Their legs
Lesser scaup bill may give a hint; in the lesser scaup it has a stronger curve on the upperside than in the greater, resulting in a distal part that looks somewhat flattened and wide in the lesser scaup—hence the vernacular name "broadbill". If the birds fly, the most tell-tale sign is the white secondary remiges, whereas in the greater scaup the white extends on the primary remiges also, i.e. far towards the wingtip. Lesser scaup females show the characteristic darker iris (bright yellow in greater scaup males and females) at closer distances. Lesser scaup drakes in nuptial plumage are often said to