Swallows are a group of passerine birds in the family Hirundidae. They are small, streamlined birds with long, slender wings, allowing them to fly very fast over long distances. Most species of swallows are migratory.
Though some swallows are cavity nesters, most swallows build nests of mud under roofs of barns and buildings, and sometimes under bridges. Swallow numbers have exploded whenever human-built structures have been built near their habitat, providing space for them to build their nests.
The most famous swallow species is the Barn Swallow, one of the most cosmopolitan bird species. It is found all over the Northern Hemisphere and winters in the Southern Hemisphere.
- Barn Swallow, Hirundo rustica
- Common House-Martin, Delichon urbica
- Bank Swallow, Riparia riparia
- Cliff Swallow, Petrochelidon pyrrhonota
- Purple Martin, Progne subis