Northern Prairie Wildlife Research Center
STATUS: Common; overall population is stable or decreasing slightly.
HABITAT: Found in taiga and on the plains and prairies, where it inhabits shallow marshes, open areas of deeper marshes, reed-bordered sloughs, natural ponds, lakes, fish and stock ponds, shallow river impoundments, wet meadows, river oxbows, ditches, edges of streams, and swampy grasslands. In migration, frequents freshwater and saltwater, occurring along the coast and along marshes, rivers, lakes and nearby cultivated fields.
SPECIAL HABITAT REQUIREMENTS: Aquatic habitats with extensive stands of emergent vegetation and large areas of open water.
NEST: Often nests in small colonies, but occasionally nests singly. Usually places nest on a floating mass of vegetation such as cattails and bulrushes and anchored to surrounding vegetation, on floating pieces of wood, or in a slight hollow atop a muskrat house. Prefers areas of emergent vegetation over water up to 3 feet deep or near open water. Sometimes uses abandoned nests of other birds including grebes, Forster's terns, and American coots.
FOOD: Does not compete strongly with fish-eating species; consumes a diet that includes aquatic and land insects, worms, small mollusks, crustaceans, and a few small fishes and grubs.
REFERENCES: Clapp et al. 1983, Forbush and May 1955, Johnsgard 1979, Low and Mansell 1983, McNicholl 1971, Tate and Tate 1982.