Perching duck

The perching ducks ("Cairininae" or "Cairinini") 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 (Livezey 1986).

The species previously included:
 * Muscovy Duck Cairina moschata
 * White-winged Duck Cairina scutulata
 * Wood Duck Aix sponsa
 * Mandarin Duck Aix galericulata

Other "perching" ducks
In addition, several species cannot with certainty be allocated to a subfamily, though they do not form a distinct clade. Rather, their characters are too ambiguous to allow unequivocal placement based on the available data (Livezey 1986, Sraml et al. 1996, Johnson & Sorenson 1999):
 * Spur-winged Goose Plectropterus gambensis
 * Salvadori's Teal Salvadorina waigiuensis (initially placed in Anatinae)
 * Blue Duck Hymenolaimus malacorhynchos
 * Torrent Duck Merganetta armata
 * Brazilian Teal Amazonetta brasiliensis
 * Comb Duck Sarkidiornis melanotos: Tadorninae or basal Anatinae?
 * Pink-eared Duck Malacorhynchus membranaceus: Tadorninae or Oxyurinae?
 * Hartlaub's Duck Pteronetta hartlaubi: Anatinae or a very distinct clade?
 * Green Pygmy Goose Nettapus pulchellus: Anatinae or a Gondwanan clade?
 * Cotton Pygmy Goose Nettapus coromandellanus: Anatinae or a Gondwanan clade?
 * African Pygmy Goose Nettapus auritus: Anatinae or a Gondwanan clade?
 * Ringed Teal Callonetta leucophrys: Anatinae or Tadorninae?
 * Maned Duck Chenonetta jubata: Anatinae or Tadorninae?