Northern Prairie Wildlife Research Center
HABITAT: Usually found near the coastline on sandy, stony, or shell beaches, barrier or spoil islands, islands with sand-gravel substrate with little or no vegetation, or on a shell berm in a salt marsh. Tends to occupy less-developed and less-polluted segments of the coast, but is also found inland along shorelines of large lakes. Wintering terns generally are found along beaches, and on isolated spits, often roosting with other larids. In migration, occurs along water courses or in large marshes.
SPECIAL HABITAT REQUIREMENTS: Sparsely vegetated islets or shorelines.
NEST: Usually found in compact colonies, but occasionally nests singly in the vicinity of other tern species in shallow depressions in the ground on bare sandy or rocky soil.
FOOD: Feeds almost entirely on fish 3 to 10 inches long, foraging on species and sizes that are most readily available; also takes crayfish, insects, nestlings and eggs of other birds, and rarely, carrion.
REFERENCES: Clapp et al. 1983, Johnsgard 1979, Ludwig 1965.