From SW Peru south through Bolivia and portions of Chile and Argentina. Voice is loud and goose-like. They are wary and seldom allow a close approach. They are found on highland salt lakes, descending in the winter to brakish estuaries and coastal marshes. They feed on minute algae, molluscs and diatoms.
Mated pairs have a characteristic hovering display flight.
Nests on ground on atolls or on coastal cliffs. It nests in the Hawaiian Islands, Marianas, Kiribati, Rose Atoll, Fiji, Tonga, the Cook Islands, Tuamotu Archipelago, Tubai Islands and Pitcairn. Breeds in Alaska and across the Praires and Great Plains in Canada and the United States. Now given protection it has increased once again. It often flies with wings held stiffly downcurved like a spotted Sandpiper, especially on its nesting grounds.