White-winged Scoter

The White-winged Scoter is the largest of the three scoter species, a heavy black sea duck with a distinctive white patch in the wing (the speculum) that shows as a bright flash in flight or a thin white line on a resting bird. Males have a black body, an orange-and-black bill with a knob at the base, and a small comma-shaped white crescent behind the eye. Females are dark brown with two faint pale patches on the face, similar to other female scoters but larger and bulkier.

This species breeds on northern lakes and winters in large numbers along coastal waters, often forming rafts alongside other scoter species.

Key field marks

• Largest scoter; heavy black body with a white wing patch (speculum) visible in flight or as a line along the folded wing
• Male: black bill with orange sides and a small basal knob, comma-shaped white mark behind the eye
• Female: dark brown with two indistinct pale facial patches, larger and bulkier than female Surf or Black Scoters

Similar species

The Surf Scoter lacks any white in the wing and instead shows bold white patches on the forehead and nape. The Black Scoter is entirely black-bodied with no white anywhere except the male's bill knob. The white speculum is the most reliable mark separating White-winged Scoter from its relatives.

White-winged Scoters breed on lakes and wetlands across the boreal forest and forest-tundra of North America and Siberia. They winter along both Atlantic and Pacific coasts of North America and parts of Eurasia, favoring open coastal waters, bays, and large lakes, often in mixed flocks with other scoters.

Behavior

Dives to forage on the bottom in shallow coastal and lake waters, often in large, loose flocks; flight is heavy and direct, typically low over the water.

Voice

Mostly silent; occasional low growling or whistling notes during courtship displays.

Feeding

Mollusks such as mussels and clams form the bulk of the diet, supplemented by crustaceans and some aquatic insects.

Nesting

Nests on the ground, often on islands or near lakes in the boreal forest, well concealed in vegetation; clutches usually contain 8-11 eggs.