The whistling-ducks were formerly known as tree-ducks, but only a few, such as the Black-bellied Whistling-Duck, actually perch or nest in trees. It is the whistled flight calls that give them their English name. They look most like ducks, but their lack of sexual dimorphism, relatively long-term pair bonds, and lack of complex pair-forming behaviour more resembles geese and swans. There are eight species of whistling ducks, Dendrocygna, within the duck, goose and swan family Anatidae, which are are found in the tropics and subtropics: Black-bellied Whistling Duck, Fulvous Whistling Duck, Lesser Whistling Duck, Plumed Whistling Duck, Spotted Whistling Duck, Wandering Whistling Duck, West Indian Whistling Duck, and the White-faced Whistling Duck.
See also: Black bellied whistling duck, Fulvous whistling duck, West Indian whistling duck, White faced whistling duck
