Greater scaup days. The down-covered ducklings are able to follow their mother in her search for food immediately after hatching. Greater scaup eat aquatic molluscs, plants, and insects, which they obtain by diving underwater. They form large groups, called "rafts", that can number in the thousands. Their main threat is human development, although they are preyed upon by owls, skunks, raccoons, foxes, coyotes, and humans. Greater scaup populations have been declining since the 1980s; however, they are still listed as a species of least concern on the IUCN Red List. The genus name "Aythya" is derived from the Ancient Greek "aithuia" which
Lesser scaup bill may give a hint; in the lesser scaup it has a stronger curve on the upperside than in the greater, resulting in a distal part that looks somewhat flattened and wide in the lesser scaup—hence the vernacular name "broadbill". If the birds fly, the most tell-tale sign is the white secondary remiges, whereas in the greater scaup the white extends on the primary remiges also, i.e. far towards the wingtip. Lesser scaup females show the characteristic darker iris (bright yellow in greater scaup males and females) at closer distances. Lesser scaup drakes in nuptial plumage are often said to