Size: L: 50 cm. Wt: 300-350g. Males and females similar.
Breeding: body generally white, with buff plumes on crown, neck, and back; legs reddish; bill bright orange-red.
Winter: plumes present, but white; bill yellow; legs yellowish.
Juvenile: plumes absent; bill yellow; legs yellowish.
Nestlings: semialtricial and downy; down white, and standing upright on crown; bill and lores greenish-yellow; legs and feet reddish-buff; iris yellowish-white.