Feeding Behavior

Forages only in flight. May forage high or low, depending on weather conditions. Typically seen foraging in flocks.

Eggs

4-5, sometimes 3-6. White, often becoming stained or spotted in the nest. Incubation is probably by both parents, about 20-27 days. Young: Apparently fed by both parents. Young are probably able to climb about inside nesting crevice before they are old enough to fly. Age at first flight may be about six weeks.

Young

Apparently fed by both parents. Young are probably able to climb about inside nesting crevice before they are old enough to fly. Age at first flight may be about six weeks.

Diet

Flying insects. Feeds on a wide variety of flying insects, including flies, beetles, true bugs, wasps, and others. May feed heavily on winged adult ants during an emergence of these insects.

Nesting

Many details of nesting remain poorly known, partly because the nest sites are so inaccessible. Courtship involves aerial displays; birds also mate while in flight, sometimes joining and then tumbling down for hundreds of feet. Nest site is usually in narrow vertical crevice in high cliff. Sometimes nests in crevices in buildings. Same site may be used for many years. Nest is shaped like shallow half saucer; made of feathers, weeds, grasses, glued together and to wall of crevice with the birds' saliva.