Knob-billed Duck

Description:

This common species is unmistakable. It is one of the largest species of duck. Adults have a white head freckled with dark spots, and a pure white neck and underparts. The upperparts are glossy blue-black upperparts, with bluish and greenish iridescence especially prominent on the secondaries (lower arm feathers). The male is much larger than the female, and has a large black knob on the bill. (wikipedia)

Habitat:

It breeds in still freshwater swamps and lakes in the tropics. This duck feeds on vegetation by grazing or dabbling and to a lesser extent on small fish, invertebrates, and seeds. (wikipedia)

Notes:

Also called Comb Duck