AppearanceDeeply forked tail — the longest of any North American swallow. Steel-blue upperparts, rusty-orange forehead and throat, and pale cinnamon underparts. Elegant, streamlined silhouette in flight.HabitatOpen country near water — farms, meadows, marshes, lakeshores. Nests almost exclusively in human structures: barns, bridges, culverts, and building eaves.BehaviourMasters of aerial insect capture, rarely pausing to perch. Skims low over fields and water in fast, sweeping arcs. Gather in huge pre-migration flocks on utility wires in late summer.SeasonalitySummer breeder arriving April–May; departs south by early October. Undertakes one of the world's longest migrations to South America.RangeBreeds across North America and Eurasia. Winters in South America and sub-Saharan Africa. The world's most widely distributed swallow.