The perching ducks were previously treated as a small group of ducks in the duck, goose and swan family Anatidae, grouped together on the basis of their readiness to perch high in trees. It has been subsequently shown that the grouping is paraphyletic and their apparent similarity results from convergent evolution, with the different members more closely related to various other ducks than to each other. The species previously included, and their current subfamilial allocation, are: Plectropterinae * Spur-winged goose Plectropterus gambensis Tadorninae Anatinae