There are two subspecies recognised:
Spot-billed Ducks are very like Mallard in behaviour, with similar feeding and foraging preferences. They focus on vegetation and dabble in the same way. Even their voice is a classic duck quack.
They like the same sort of habtats; inland and coastal wetlands, preferring open, low ground, shallow freshwater lakes and marshes with plenty of emergent vegetation.
The main difference between these and the Chinese Spot-bills, is that the primary feathers are white. These can be seen even when the wings are folded. The sides of the head are a purer buff, and there is a small area of orange/red at the base of the bills. This is more distinct in the drake.
Spotbills lay 6-14 buffy-coloured eggs, which are incubated for 24 to 26 days. Wild nesting females, young and eggs may be predated by water and marsh-dwelling snakes. In aviculture, they breed readily and care should be taken enclosing them with other ducks. They readily hybridise with several closely and not-so-closely related species, and these offspring are frequently fertile.