The adult male has a dark grey beak and pink eye-rings. The adult female has a bone-coloured beak, grey eye-rings and ear patches that are whiter and more distinctive than those of the male. The feathers of its underparts and underwing coverts have larger white margins than those of the male, leading to a more barred or scalloped pattern to its plumage. Its legs and feet are a little lighter than those of the male. Moulting appears to take place in stages in late summer—some time between January or February and April or May, and is poorly understood.