STATUS: Common.
HABITAT: Inhabits marshes, lakes, ponds, sloughs, potholes, and marshy borders of creeks and rivers, or ephemeral habitats when conditions are suitable. Prefers wetlands with a good interspersion of emergent vegetation, especially cattails and bulrushes. During migration, found on rivers, lakes, ponds, reservoirs, or sewage lagoons, and on freshwater or brackish waters in winter.
SPECIAL HABITAT REQUIREMENTS: Freshwater wetlands, with shallow water 1 to 4 feet deep and emergent vegetation interspersed with areas of open water.
NEST: Constructs floating display platforms, egg nests, and brood nests located in and anchored to emergent vegetation, usually within 4 feet of open water and over water 1 to 4 feet deep. May also nest on top of a muskrat house.
FOOD: Primarily dabbles and grazes, but also dives. Eats a variety of plant foods, which make up 89 percent of the diet. During winter often grazes on pastures and cultivated fields. Eats mostly pondweeds, sedges, algae, grasses (especially wild rice), and other plants; also eats fishes, tadpoles, worms, crustaceans, spiders, beetles, dragonflies, and bugs.
REFERENCES: Cramp and Simmons 1980; DeGraff et al. 1980; Fjeldsa 1977; Fredrickson 1970, 1977; Gullion 1954; Johnsgard 1975a; Jones 1940; Kiel 1955.