Saturday, June 2, 2012

>>Genus Cairina


A domestic Muscovy Duck ("Barbary Duck")
Scientific classification
Fleming, 1822
See text.
Cairina is a genus of ducks in the bird family Anatidae.
It has two species, which are similar anatomically but quite distinct in external morphology:
  • Muscovy Duck, Cairina moschata
    • Domesticated Muscovy Duck, Cairina moschata momelanotus  sometimes Cairina momelanotus
  • White-winged Duck, Cairina scutulata
These were initially placed as type genus in the "Cairininae" (or "Cairinini"), a supposed group of "perching ducks" which was somewhat intermediate between dabbling ducks and shelducks. However, this assemblage turned out to be paraphyletic, and the Cairina species were moved to the dabbling duck subfamily Anatinae, to which they seemed closest from the data available at that time.
Analysis of the mtDNA sequences of the cytochrome b and NADH dehydrogenase subunit 2 genes (Johnson & Sorenson, 1999), meanwhile, has indicated that this is probably not correct, and that moreover the two species usually united in Cairina are not even closely related to each other, which is also suggested by the biogeography of their distribution:
The Muscovy Duck seems a distant relative to the genus Aix which for example contains the North American Wood Duck. Together, they appear related to the shelducks and C. moschatawould thus be placed in the Tadorninae.
The White-winged Wood Duck, on the other hand - which has sometimes been allied with the enigmatic Hartlaub's Duck (Madge & Burns, 1987) - should according to the molecular analysis moved to its old genus, Asarcornis, and could in fact be a peculiar diving duck.

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