Today's Wildlife of the Week are the Greater and Lesser Scaup, featured in John H. Rappole's book, Wildlife of the Mid-Atlantic, now in paperback. These attractive ducks are quite common in the coastal plains of the region from fall through spring, so you've probably seen them before without realizing it.
It can be a struggle to tell these two relatives apart. Both have dark heads, chests, and hindquarters in addition to piercing gold eyes, grey wings, and bluish bills (which has earned the Greater Scaup its nickname "Bluebill"). The females of each species are fully brown with pale blue bills. Both are diving ducks, who will plunge underwater to find the mollusks and vegetation they feed on. Large flocks even tend to have both breeds of Scaup in them. So how does one tell them apart?
As their names suggest, the Greater Scaup is larger than the Lesser Scaup. The Greater's dark head tends to have a bright green sheen to it, similar to a mallard, while the Lesser Scaup tends to have an iridescent purple shine (although they sometimes can have a green shine as well). The most reliable method of distinguishing the two birds, however, is to look at the shape of their head. The Greater Scaup has a large forehead with an otherwise smooth curve to its head. Both sexes of the Lesser Scaup, however, have a less prominent forehead and a small "crown" of puffed feathers.
Next time you head toward the Atlantic coastline, keep an eye out for these distinctive diving ducks. Maybe you'll even be able to tell them apart! For more information about this bird and other regional wildlife, check out a copy of Rappole's book.