Size: L: 50 cm. Wt: Males: 990 g. Females: 850 g. Sexually dimorphic in size and colour. This species is not seasonally dimorphic, but males exhibit eclipse plumage.

Male: body mostly grey; belly white; tail coverts black; wings pale chestnut, with white secondaries showing as patch when swimming; bill grey.

Eclipse Male/Juvenile: close resemblance to females.

Female: body mottled brown; belly white; bill grey with orange sides.

Duckling: similar to Mallard, but upperparts more brown or buff; paler eye stripe.