When seeing the greater scaup (Aythya marila), the overall impression is that of a big, thickset duck. From a distance, the male appears grayish on top, whitish on bottom, and dark at both ends. Up close, you will see that his back actually sports an attractive pattern of fine barring. Likewise, his head has a greenish gloss. Also note his yellow eyes and blue-gray bill, which gives him the nickname of “bluebill.”
The female is dark brown overall, but her yellow eyes and the large white patch at the base of her bill do provide some contrast. Her bill is also blue, but tends to be darker than that of her mate.
In flight, both the male and the female display a white wing stripe. They fly directly with strong, fast wing beats.
Best Field Mark
- White wing stripe extending all the way to the primary flight feathers.
Greater scaup are usually quiet. However, they sometimes obligingly announce themselves with a loud “scaup.” Males may also whistle nasally during courtship, while the female may give raspy “harrr” notes if alarmed.
Distribution & Occurrence
It is difficult to say for certain how common the greater scaup is in inland states such as Kansas, since confusion with the lesser scaup occurs frequently. However, the former species definitely is much less likely to be found away from the coast than the latter, preferring large, open bodies of water.
Nevertheless, it appears that a few greater scaup can be found in Kansas fairly regularly, mostly during spring and fall migration, but also over the winter. This duck may turn up just about anywhere in the state, although some of the best sightings have been at Scott State Park.
The greater scaup is noted for its physical prowess. It requires a long running start to get airborne, but once in flight it can reach speeds of up to 75 mph. On the water, it can dive as low as 20 feet under the surface, and it can stay underwater for up to a minute.
This is a species of diving duck, but it will occasionally dabble like a mallard. Its food is a combination of seeds, aquatic vegetation, and mollusks. Greater scaup typically eat during the daytime hours, but will feed at night in the colder months if human disturbance disrupts their routine.
While the greater scaup does not nest in Kansas, wintering birds may provide interesting displays of courtship and bonding behavior, as new pairs are formed every winter before spring migration. A group of males will gather around a single female, fight for the closest position, and then try to impress her by flinging their heads backward.
Attracting greater scaup is not likely to be within the reach of most backyard birdwatchers.
Hunters may have some luck in taking this species if they choose one of the larger lakes on which to spread their decoys. An ideal setup will include long lines of bluebill decoys.
Telling the two scaup apart is one of the toughest challenges in duck identification. Both male and female lesser scaup are smaller with more tapered bills, and they tend to have a somewhat peaked head shape. They give the appearance of having half a wing stripe, as the white can only be seen on the secondary flight feathers. Also, the male lesser scaup has a purplish head and pale gray sides, instead of the greenish head and stark white sides of the greater scaup. However, distance and lighting can wreak havoc on the visibility of most of these field marks. The length of the wing stripe is the most reliable feature. Barring a glimpse of that, identification may not always be possible.
Photos, audio, and more information from Cornell’s All About Birds site.