Indian Spot-billed Duck

The Indian spot-billed duck is a large dabbling duck that breeds without migrating in freshwater wetlands across the Indian subcontinent. Its name comes from the red spot at the bill base seen in mainland Indian birds. On the water it is recognisable from far off by the white tertials that form a stripe along the side, and in flight by a green speculum with a broad white band at its base (Wikipedia, general species account).

It was long treated as one species with the eastern spot-billed duck, which is the form usually expected in Vietnam.