The trailing legs and rounded wings of these slow flying ducks makes them look bigger than they are. Both species are primarily Mexican. In the U.S., the Black-bellied Whistling Duck is found only in south Texas and Louisiana. The Fulvous Whistling Duck also occurs there and in Florida with occasional stragglers further north along both coasts and the Mississippi Valley. The Fulvous Whistling Duck is the more common of the two species in the United States.
Sexes are alike.
Both species have shrill whistling calls.