Date of this Version
Whistling ducks comprise a group of nine species that are primarily of tropical and subtropical distribution. In common with the swans and true geese (which with them comprise the subfamily Anserinae), the included species have a reticulated tarsal surface pattern, lack sexual dimorphism in plumage, produce vocalizations that are similar or identical in both sexes, form relatively permanent pair bonds, and lack complex pair-forming behavior patterns. Unlike the geese and swans, whistling ducks have clear, often melodious whistling voices that are the basis for their group name. The alternative name, tree ducks, is far less appropriate, since few of the species regularly perch or nest in trees. All the species have relatively long legs and large feet that extend beyond the fairly short tail when the birds are in flight. They dive well, and some species obtain much of their food in this manner. Eight species are represented in the genus Dendrocygna, including all three of the species included in this book. A ninth species, the African and Madagascan white-backed duck (Thalassornis leuconotus) , is considered by the author (Johnsgard, 1966) to be an aberrant whistling duck.
Two of the three species included in this book regularly nest in the southern United States, while the third (the Cuban whistling duck) might be regarded as North American on the basis of its occurrence in the West Indies, although it is not known to have ever reached continental North America.