Northern Prairie Wildlife Research Center
HABITAT: Primarily inhabits large saltwater and freshwater marshes; also found on marshy bays, marshy parts of islands, marshy edges of streams and lakes, sloughs, dikes in evaporation ponds, estuarine islands, marshes adjacent to barrier beaches, and dredge-spoil islets. In winter, occurs in harbors, marshy bays, estuaries, lagoons, and inlets along coastal areas, occasionally occurring inland along lakes and ponds.
SPECIAL HABITAT REQUIREMENTS: Extensive marshy areas with vegetated nest sites partly open to water.
NEST: Usually found in small colonies, nesting on mats of floating dead vegetation, flattened reeds and cattails, large muskrat houses near the edges of open pools of water, floating rootstalks of cattails, or sometimes in a shallow depression in sand or mud. May also locate nests on sand or gravel bars, beaches, or grassy islands. Sometimes uses old or abandoned nests of western and pied-billed grebes.
FOOD: Feeds over or near the marshes in which it nests. Eats small fish, insects, crustaceans, and frogs.
REFERENCES: Bergman et al. 1970, Clapp et al. 1983, Forbush and May 1955, Johnsgard 1979, Low and Mansell 1983, McNicholl 1971.