The whistling ducks or tree ducks are a subfamily, Dendrocygninae of the duck, goose and swan family of birds, Anatidae. They are not true ducks. In other taxonomic schemes, they are either considered a separate family Dendrocygnidae, or a tribe Dendrocygnini in the goose subfamily Anserinae. The subfamily has one genus,
Dendrocygna, which contains eight living species, and one undescribed extinct species from Aitutaki of the Cook Islands.