Greater scaup are almost the size of redheads. In hand, they are easily distinguishable from lesser scaup by size and by the white wing stripe extending beyond the secondaries into the primaries. In the field the two species are sometimes difficult to separate. Drakes are black on both ends and white in the middle. Hens are dark brown with a white mask around the base of the bill.

The common vocalizations are the discordant scaup and purring pbbbrr of the female. Greater scaups form large flocks, sometimes mingling with lesser scaups in fall and winter.

They are an abundant migrant and winter visitant in the Columbia River estuary and common to abundant on coastal bays and lower river segments. Except for regular occurrence in the Columbia River estuary and Coos there are few summer records.

Hear the call of the greater scaup

Photo by Paul Sullivan, Flickr