Barn Swallow, common name for the most abundant species of the swallow family. A long-distance migrant, it breeds around the world in the northern hemisphere and winters in the southern hemisphere. The North American subspecies ranges from Alaska and Greenland to Tierra del Fuego. Male barn swallows are glossy-blue above; the underparts vary from white to deep chestnut, depending on the subspecies. The forehead and throat are bright chestnut, bordered by a complete or partial band of blue across the chest. The tail is deeply forked, and each tail feather, except the central pair, has a white spot on its inner web. Females are similar, but slightly duller in color, with a shorter tail. Most barn swallows now nest in man-made structures, usually near water, such as buildings, culverts, bridges, or even ferries. Their original nest sites were probably caves and crevices in cliffs.