Greater Scaup (Aythya marila)

The only circumpolar member of the Aythyini tribe, this is a winter male. Two subspecies are usually recognized. However the name of birds in East Asia is disputed with most sources applying the name A. m. nearctica which ranges across North America to East Asian birds. However Banks (1986) found East Asian birds indistinguishable from European birds in which males are more finely marked above. The name A. m. mariloides previously applied to East Asian populations is invalid.