STATUS: Common.
HABITAT: Inhabits freshwater wetlands and lakes from tundra to shortgrass and mixed prairie, preferring permanent to temporary waters. Commonly associates with diving ducks, and in winter frequents coastal marshes and bays, wet meadows, and shallow freshwater and brackish ponds.
SPECIAL HABITAT REQUIREMENTS: Large lakes, ponds, marshes, sluggish streams and rivers, with open water and exposed shoreline.
NEST: Nests in a hollow on dry ground on an island or on shore, in tall grasses or weeds, or at the base of a tree or bush, as far as 400 yards from water.
FOOD: Feeds by grazing and gleaning in wet or dry pastures and fields, by dabbling on the water surface in shallow water along marsh edges and sloughs, and by scavenging for wild celery after diving ducks have torn plants loose from bottom. Primarily vegetarian, eats mainly leaves, stems, and buds of aquatic plants; also feeds on waste grains, mollusks, crustaceans, and insects.
REFERENCES: Baldwin et al. 1964, Bellrose 1976, DeGraff et al. 1980, Johnsgard 1975b, Low and Mansell 1983, Palmer 1976a, Terres 1980, Verner and Boss 1980.