Easily outsizing other scoter species in winter flocks on coastal waters, the White-winged Scoter is a large sea duck with a heavy, sloping bill and bold white patches in the wing. Males are velvety black with a dashing, upturned comma of white around the eye and an orange-tipped bill. In winter these birds eat mussels, holding their breath for a minute or more, deep underwater, while they wrestle the shellfish free from rocks. They breed around lakes of the far north, where their diet changes to crustaceans and insects.
In winter along Atlantic and Pacific coasts, scan for White-winged Scoters in large mixed flocks of sea ducks, especially by rocky shorelines or over sandbars. White-winged Scoters are usually the scarcest of the three scoter species in North America, but scanning through such flocks will usually turn up a larger bird with telltale white patches on the inner wing (very noticeable in flight and often partly visible on resting birds). During migration, after heavy storms, or when the Great Lakes have frozen over, they often show up on inland lakes.
For many years, the Velvet Scoter of western Eurasia and Stejneger’s (Siberian) Scoter of eastern Eurasia were combined with White-winged Scoter as a single species, but in 2019 taxonomists decided to treat them as 3 separate species.
Although the White-winged Scoter winters primarily along the coasts, small numbers winter on the eastern Great Lakes. Populations on the Great Lakes may have declined during the 1970s but now appear to be increasing in response to the invasion of the zebra mussel, a new and abundant food source.
Female White-winged Scoters return to nest in the area where they hatched. This strong bond between hatching place and nesting is called “natal philopatry.”
The White-winged Scoter often nests near gull colonies. Although the gulls would readily eat the eggs and chicks of the scoter, the dense vegetation where the scoter nests keeps them safe. The scoters are probably not attracted to the nesting gulls per se; instead, both species seem attracted to the same kinds of habitat for nesting.
The oldest recorded White-winged Scoter was a female, and at least 18 years, 1 month old when she was observed at a nest in Saskatchewan, Canada.
Ducks
