Very slightly smaller than their Old World cousins, the American Comb Ducks are heavily built ducks of wooded wetlands.
Sexes are easily distinguishable. Males are much larger than females, and have a very large, black knob on the top of the bill at the base of the forehead. In the breeding season this knob becomes more prominent. Females have a relatively minor bump in the same spot. Both sexes have a speckled head, white front and black flanks, back, wings and tail.
Neither sex has much to say, except when alarmed or displaying. In the wild, family groups are often a harem of ducks with a dominant male. It is usually best to keep birds as a trio, two ducks to a drake, so that the drake is less likely to be aggressive to a single female.
The American Comb Duck tends to be the one most common in European aviculture; conversely the larger Old World or African Comb Duck is favoured in North American collections.
American Comb drakes will breed with one, or multiple females in a harem. They typically nest in cavities, often several metres up, but may use ground cover if stumps or logs are unavailable. They lay a fairly large clutch, at 7-15 eggs, and may utilize shared nests. Males take part in rearing young with multiple females.