Also grazes on grass. Kg Heavy build duck with large bill. Upper parts dark blue-grey and feathers on shoulders and back have a light metallic sheen to their centres. Upper brest blue-grey. Under parts white.
Adult males have light grey head, becomes almost wholly white in old birds, and deep orange bill.
Both sexes have orange feet and white eye ring. Common and widely distributed. Feeds in shelter of kelp beds and close inshore on a variety of marine life, but largely on shellfish. Breeding begins with egg laying in mid September to mid October.