Both sexes of the Australian Shelduck are large, blackish ducks with a reddish-chestnut breast and white wing coverts. The female is slightly smaller with white eye-patches; the male shows a white neck ring. Underparts are black on both sexes. The bill, legs and feet are blackish or dark grey; their irises are brown. The youngsters have extensive brown feathering on the head and neck, no neck ring, some whitish feathering between eye and bill.