White-Winged Scoter

Fascinating facts about the White-Winged Scoter

• The white-winged scoter is the largest of the three North American scoter species, with males weighing up to 2,128 g and measuring as long as 60 cm. Females are smaller, ranging from 950 to 1,950 g and 48 to 56 cm, but both sexes share a robust build. Its wingspan reaches 80 cm, giving it a powerful silhouette on open water. This bulk and span make it the most commanding scoter in flight and on the surface.
• White-winged scoters need three years to acquire their definitive adult plumage. Second-year males look like adults but show reduced eye markings and browner flanks, while full adult males are entirely black with a striking white eye ring and a white speculum on the wing. This delayed plumage change means younger birds retain a more subdued appearance until they reach maturity. The colour contrast only becomes fully evident after the third year.
• The white-winged scoter's gizzard makes up about 8 % of its body mass and is strong enough to crush hard-shelled molluscs. This adaptation lets the bird exploit prey such as rock clams, Atlantic razor clams and Arctic wedge clams in marine habitats, while in freshwater it favours the amphipod Hyalella azteca. By grinding these tough foods, the gizzard expands the bird's dietary niche beyond that of smaller scoters.
• During the breeding season a female white-winged scoter may end up looking after a large number of ducklings because neighbouring females become aggressive and their nests become confused, causing brood mixing. By the end of the brooding period she can be caring for as many as forty young, each drawn from several clutches. In especially dense colonies this mixing can produce a massive creche, sometimes containing up to a hundred ducklings gathered together.
• White-winged scoters feed on the bottom of lakes and seas, diving to reach their prey. In wintering areas they can plunge to depths of five to twenty metres, while on the breeding grounds they usually feed only one to three metres below the surface, and their large size enables them to dive deeper and take larger, hard-shelled molluscs than some other scoter species.

Sources

Every fact above was checked against these pages, and kept only where one of them states it.

• Wikipedia

At a glance

About the White-Winged Scoter

In the dark, mysterious waters of the northern hemisphere, the White-Winged Scoter glides effortlessly, its glossy black feathers glistening like polished onyx as it dives in search of crustaceans and mollusks to devour. With a swift, powerful stroke of its wings, it propels itself through the waves, its snow-white wing patches flashing like beacons as it rises to the surface, a fleeting glimpse of elegance in the harsh, rugged landscape. As it forages, its haunting, whistling calls echo across the water, a haunting serenade that fills the crisp, salty air.

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