Northern Prairie Wildlife Research Center
HABITAT: Occurs virtually throughout the whole United States wherever suitable nest sites are found, but favors farmlands, open forests, rural, and suburban areas.
SPECIAL HABITAT REQUIREMENTS: Overhead protection, especially buildings, for nesting.
NEST: Originally nested on cliffs and in caves and rock crevices in mountains, along rocky coasts, and on high shores of lakes and rivers. Still uses such sites in the north and on the Pacific Coast, but in other areas nests on horizontal beams or ledges inside barns or other buildings, or under bridges, culverts, or wharves. Usually nests colonially.
FOOD: Prefers to feed over water or fields, catching flying insects (especially flies) on the wing.
REFERENCES: DeGraff et al. 1980, Forbush and May 1955, Johnsgard 1979, Samuel 1971.