Breeds in the far north of North America in Labrador and Newfoundland to the southeast Hudson Bay, in Alaska. Also the Siberian side of the Bering Straits east of the Yana River. It winters further south, on the coasts of the northern USA and Canada, on the Pacific coast south to the San Francisco Bay region and on the Atlantic and Gulf of Mexico coasts, and in Asia as far south as China.
Food
Crustaceans and molluscs while migrating or wintering on the sea-coasts. Insects and their larvae, especially caddisflies, fish eggs and, more rarely, vegetation such as duck weed while nesting on freshwater.
BirdLife International Species Factsheet