Northern Prairie Wildlife Research Center
STATUS: Uncommon; nesting populations have been greatly reduced due to use of pesticides and herbicides by rice farmers.
HABITAT: Inhabits wetland habitats, preferably marshes and sloughs or ponds surrounded by low bushes or willows, and emergent vegetation such as bulrushes. Also in tule or bulrush swamps, in centers of ponds, and in irrigated rice fields. Roosts in marshes in the evenings.
SPECIAL HABITAT REQUIREMENTS: Freshwater marshes and sloughs.
NEST: Colonial nester, sometimes with or near colonies of great blue and black-crowned night-herons, or snowy egrets. Generally nests in large beds of bulrushes or reeds several feet above water; on floating mats of dead plants, in cattails and hardstem and alkali bulrush; or infrequently on dry land. On land, prefers to nest on the ground among low shrubs and mixed forbs rather than in grass or cactus. Generally nests in areas well covered with vegetation.
FOOD: Feeds by probing in freshwater marshes. Consumes insects, newts, leeches, worms, mollusks, crustaceans (especially crayfish), frogs, fishes, and some snails. After nesting season, feeds in larger marshes as well as in irrigated fields.
REFERENCES: Burger and Miller 1977, Oberholser 1974a, Palmer 1962, Ryder 1967, Terres 1980.