Scoters are dark sea ducks that spend most of the year on oceans and saltwater bays. The White-winged Scoter is the largest scoter. During fall and winter months, it can be seen occasionally on the water but most often flying by Edmonds. Flocks typically fly low over the sea and in irregular lines. It winters along the West Coast from Alaska to California.

The male is black and shows a white arc under its eyes. The female and the immature scoter are a rich blackish-brown. Regardless of sex or age, every White-winged Scoter shows the large white patch on the inner trailing edge of the wings. The white patch is unmistakable in flight and can often be seen when the bird is at rest on the water.

When foraging, the White-winged Scoter dives for shellfish, usually over sandy shoals or gravel. When on the ocean, this is beyond the wave zone but within sight of shore. When swimming under water, this scoter propels itself by feet and with its wings partly spread for thrust and maneuvering. It swallows small items while under water and brings large mollusks to the surface where they are swallowed whole. This scoter also eats aquatic insects and a small number of fish. Sea lettuce, pondweed, and other plant materials are also part of its diet.

The White-winged Scoter nests in northern forests, below the tundra line, on large freshwater ponds, lakes and rivers. On the coast it nests along brackish water. In courtship several males may surround a female. The courtship displays of a male include lowering its head, arching its back, and rushing forward on the water a short distance. Several may pursue a female on short chases under water. Nesting begins late, with clutches not complete until late June or early July. The nest is usually close to water, on the ground in a patch of dense brush. The nest is a shallow depression, sometimes with plant material and lined with down. There are usually 9 – 10 eggs, incubated by the female for about a month.

The young scoters leave the nest shortly after hatching. The female tends to them and broods them while they are small, but they feed themselves. Their age at first flight is not well know. Speculation is that it occurs some time between 7 and 11 weeks of age. Migration to wintering grounds usually takes place in small flocks. When migrating overland, the flocks fly very high.

The White-winged Scoter often nests near gull breeding colonies. Gulls would eat the eggs or chicks if this scoter did not place its nest under dense vegetation.

The longest-living White-winged Scoter was a female that was 18 years and one month of age when she was found at a Saskatchewan nest site.

The White-winged Scoter is mostly silent. The calls of several of these scoters on their breeding grounds can be heard here: https://www.xeno-canto.org/181618.

— By Carol Riddell

Carol Riddell manages the bird education displays, on behalf of Pilchuck Audubon Society and Edmonds Parks & Recreation, at the Olympic Beach Visitor Station.