White-winged Scoter, Melanitta deglandi or Melanitta fusca deglandi

The White-winged Scoter (Melanitta deglandi or Melanitta fusca deglandi) is a bulky sea duck. It is characterized by its large bill and bulky shape. This is the biggest species of Scoter. The females range from 2.1 to 4.2 lbs and 19 to 22 inches, averaging 2.6 lbs and 21 inches. She is brown with pale patches on her head. The male ranges from 3 to 4.7 lbs and from 21 to 24 inches, averaging 3.6 lbs and 22 inches. He is all black, except for white around the eye and a white speculum. This scoter’s bill has a large knob and a black base.

There are a number of differing traits of the Eastern Siberian race and the American race from Alaska to Canada to west of the Hudson Bay. Males of the American subspecies have browner flanks, dark yellow coloration of most of the bill and a lesser tall bill knob, approaching the Velvet Scoter. The Asian form has a very tall knob at the base of its mostly yellow-orange bill. The females are identical in the field.

The White-winged Scoter was named after French zoologist Dr. Come-Damien Degland.

It was formerly considered to be conspecific with the Velvet Scoter, and some taxonomists still regard it as conspecific. These two species, and the Surf Scoter, are put in the subgenus Melanitta, distinct from the subgenus Oidemia, Black and Common Scoters.

The White-winged Scoter breeds over the far north of Asia east of the Yenisey Basin, and North America. It winters further south in temperate zones, on the Greater Lakes, the coasts of the Northern USA and the southern coast of Canada, and Asia as far south as China. It forms big flocks on suitable coastal waters. These are tightly packed, and the birds have a tendency to take off together.

The lined nest is built on the ground and close to the sea, lakes or rivers, in woodland or tundra. 5 to 11 eggs are laid. The pinkish eggs average 1.8 inches in breadth, 2.7 inches in length and 2.9 oz in weight. The incubation stage can range from 25 to 30 days. After about 21 days, neighboring females might start to behave aggressively towards other nesting females, resulting in confusion and mixing of broods. By the time the female is done brooding, she may be tending to as much as 40 offspring due to the mixing from these conflicts. She will tend to her brood for up to three weeks and then abandon them, but the young usually stay together for another three weeks. Flight capacity is thought to be gained by 63 to 77 days of age.

In fresh water, this species primarily feeds on crustaceans and insects; while in saltwater areas, it feeds on mollusks and crustaceans. The preferable foods of American subspecies are an ampiphod (Hyalella azteca) in fresh water, and rock clams (Protothaca stamina), Atlantic razors (siliqua spp.) and Arctic wedge clams (Mesodesma arctatus).

Image Caption: Adult male White-winged Scoter (Melanitta deglandi). Credit: Len Blumin/Wikipedia (CC BY 2.0)