Scaup duck is a term commonly used to describe two species of diving ducks: the lesser scaup (Aythya affinis) and the greater scaup (Aythya marila). These birds are also known by various other names that are more commonly used in some parts of the world. For instance, in North America, the lesser scaup is called bluebill, while the greater scaup is known as blackhead. In Europe, the greater scaup is commonly referred to as the broadbill. Other alternative names for these birds include raft duck, creek coot, and ring-necked duck. However, regardless of the name used, these ducks are known for their diving abilities, their voracious appetite, and their stunning plumage.