Northern Prairie Wildlife Research Center
STATUS: Locally abundant.
HABITAT: Inhabits fairly extensive areas of open water bordered by tall emergent plants. Found on marshes, lakes, and bays; in winter may be found on salt, brackish, and freshwater where small fishes are abundant.
SPECIAL HABITAT REQUIREMENTS: Open, fresh lakes bordered by rushes or tules.
NEST: Nests in colonies of hundreds, even thousands of pairs at some lakes, but occasionally nests singly. Builds nests in colonies closely spaced, with territories consisting of only immediate vicinity of nest. Constructs nests in extensive areas of open water bordered by tules or rushes, in emergent vegetation, or on dry land. Prefers to nest near or on open shallow water about 12 inches deep. Anchors nests to, or builds on, submerged roots of bulrushes or other plants.
FOOD: Captures food during dives underwater. Consumes primarily fishes. Also takes mollusks, crabs, marine worms, salamanders, and insects.
REFERENCES: Grinnell and Miller 1944, Lindvall and Low 1982, Palmer 1962, Terres 1980, Wetmore 1924.