The whistling ducks or tree ducks are a subfamily, Dendrocygninae, of the duck, goose and swan family of birds, Anatidae. In other taxonomic schemes, they are considered a separate family, Dendrocygnidae. Some taxonomists list only one genus, Dendrocygna, which contains eight living species, and one undescribed extinct species from Aitutaki of the Cook Islands, but other taxonomists also list the white-backed duck (Thalassornis leuconotus) under the subfamily.

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