STATUS: Common.
HABITAT: Inhabits coniferous, deciduous, and mixed forests, preferring open or broken woods, or the edges of dense woodlands. Occurs around towns, in woodland clearings, especially near lakes and streams, and if snags are present, in canyons, and in mountains from the foothills to near timberline.
SPECIAL HABITAT REQUIREMENTS: Cavities or crevices for nesting and open terrain or forest openings for feeding.
NEST: Builds nests in old woodpecker holes, natural tree cavities, crevices in rocky cliffs, nesting boxes, niches of old buildings, and when cavities are scarce, in old nests of cliff swallows and burrows of bank swallows. In Colorado, prefers cavities in ponderosa pine but also nests in aspen and other trees.
FOOD: Consumes only insects, which catches and eats while on the wing.
REFERENCES: Bailey and Niedrach 1965, Beal 1918, Bent 1942, Combellack 1954, Johnsgard 1979, Scott et al. 1977, Terres 1980.