Ducks, Geese, and Swans of the World: Tribe Merganettini (Torrent Duck)

Torrent Duck This remarkable stream-dwelling duck of the Andean mountains is certainly one of the most specialized of all waterfowl, and in part its anatomical and behavioral specializations have obscured its basic relationships, which appear to be with either the perching ducks or the dabbling ducks. In the absence of definitive evidence, it seems reasonable to maintain a separate tribe for this species, which exists as a series of relatively isolated populations between Venezuela and Tierra del Fuego that vary greatly in male plumage characteristics. Torrent ducks are essentially cavity- or ledge-nesting forms, although only a few nests have been found, and much still remains to be learned of their breeding biology