The name, "Rough-winged" comes from tiny hooks on the outer primary, which gives the feather a rough feel, however, the purpose is unknown.
The "Rough-winged" does not zigzag erratically as the "Barn Swallow", but rather glides and sails more directly while snatching insects in flight.
Because he is so sober looking with none of the flash of his swallow cousins, the "Rough-winged Swallow" impresses prospective mates by spreading the white feathers under his tail coverts during courtship flights. This bird breeds throughout the United States, and prefers to do so in solitary pairs rather than in a colony.
Calls or song.
He issues a low, drawn out and unmusical "trit trit", often doubled.
Population and distribution.
The "Rough-winged Swallow" winters north to Southern California, on the Gulf Coast and southern Florida.
These swallows are not particular about their dwelling places and adapt to any kind of cavity, usually tunneling into steep banks of clay, sand or gravel. The female incubates six or seven white eggs in a nest of grass and rootlets. The habitats near riverbanks, sometimes flood in high tides, destroying eggs and young. Roughwings also build in masonry holes, drainpipes, crannies under bridges and culverts, as well as in abandoned homes of kingfishers and ground squirrels.