The lesser and greater scaup are better known as bluebills. As the nickname implies, both subspecies have blue bills, and the two birds are very difficult to differentiate. Each is part of the diving ...

The population estimate for greater (Aythya marila) and lesser (Aythya affinis) scaup (combined) has declined dramatically since the early 1980s to record lows in 1998. The 1998 estimate of 3.47 ...

Identifying environmental metrics specific to lesser scaup (Aythya affînis; scaup) spring migration chronology may help inform development of conservation, management and population monitoring. Our ...

The scaup, it could be said, are difficult ducks to deal with. Two species occur in North America, but you can’t tell by looking. Well, you can, but you have to know what you’re looking for, and you ...