Subspecies of the greater scaup and their names

The name Fuligula mariloides Vigors, presently used by many authors for a subspecies of the Greater Scaup, Aythya marila, was originally proposed for the Lesser Scaup, A. afinis, and may not be used in combination with the name marila. The name mariloides has been applied to a population of Greater Scaup in Kamchatka and the Commander Islands, supposedly distinguished by small size and dark dorsal color, or for that population and the one in North America, otherwise known as A. m. nearctica. Evidence for a subspecifically distinct population in eastern Asia is lacking, and A. marila is best considered to consist of only the Eurasian A. m. marila and the American A. m. nearctica. There is some interchange of the two subspecies in migration.