Barn Owl, common name for members of a family of birds that differ from the typical owls in having a heart-shaped face rather than a circular one. Barn owls also have longer legs and smaller eyes, which are never yellow as in some typical owls. They hunt at night, and their food consists principally of small mammals. Most have mottled brown upperparts and, except for the sooty owl of Australia, pale underparts, usually lightly speckled. Of the dozen species that are distributed throughout the temperate and tropical regions of the world, only one, the worldwide common barn owl, is found in the United States. It ranges northward to southern Canada in the breeding season; the northern populations are migratory. It nests in hollow trees, barns, belfries, and abandoned buildings. The eggs of the common barn owl, usually five to seven in number, are chalky, unmarked white.