Size: L: 100 cm. Wt: 800-950g. Males and females similar.

Breeding: body completely white; bill yellow, with bare greenish skin on face; legs and feet black; long plumes trailing from back.

Winter and Juvenile: plumes absent; bill and legs duller; bare skin on face yellow.

Nestling: semialtricial and downy; down long, white, with fine tips, stiffer on crown producing crest; down thin on neck and underparts, and absent from some areas of the head; bill pink on hatching, then yellow; legs and feet greyish-green; bare facial skin blue-grey, becoming yellow; iris whitish