Knob-billed Duck

The knob-billed duck is a very large, unmistakable duck 56–76 cm long, with a 116–145 cm wingspan and weight of 1.03–2.9 kg. Adults have white head, neck and underparts flecked dark, glossy blue-black upperparts and a heavy black bill. Breeding males develop a prominent rounded knob above the bill; females are smaller and lack the enlarged comb (Wikipedia, general species account).

It inhabits tropical freshwater swamps, lakes, floodplains and wooded wetlands across Africa, Madagascar, South Asia and mainland Indochina. Birds graze, dabble and forage on land for seeds, grain, aquatic plants, insects and small aquatic animals, often perching and roosting in trees. Nests are placed in large tree cavities or occasionally dense vegetation. Females lay six to fifteen eggs and incubate them for about 28–30 days; several females may use one cavity (Wikipedia, general species account).