In poor light, Cliff Swallows look brownish with dark throats and white underparts. In good light you’ll see their metallic, dark-blue backs and pale, pumpkin-colored rumps. They have rich, brick-red faces and a bright buff-white forehead patch like a headlamp. Some juveniles show whitish throats in summer and fall.
Cliff Swallows zoom around in intricate aerial patterns to catch insects on the wing. When feeding in flocks with other species of swallows, they often stay higher in the air. They build mud nests in colonies on cliff ledges or under bridges, eaves, and culverts.
Cliff Swallows traditionally built their nests on vertical cliff faces. With the expansion of road infrastructure they have adopted many bridges, overpasses, and culverts as their colonial nesting sites. They feed in areas near and over water, frequently mixing with other species of swallows.
Regional Differences
Most Cliff Swallows in North America have whitish foreheads; however, birds from the Mexican population (which extends into the southwest U.S.) have dark chestnut foreheads.