Feeding Behavior

Forages in rapid flight, pursuing flying insects and capturing them in wide bill. May forage singly or in flocks. Spiders and sedentary insects in diet may have been captured after being carried high by air currents, or taken from trees by the swifts while hovering briefly in flight.

Eggs

6, sometimes 3-7. White. Incubation is by both sexes, 18-19 days. Young: Both parents care for and feed young. At some nests, one or two additional adults may help parents incubate eggs and feed nestlings. Feeding visits to nest are frequent: average once every 12-18 minutes, perhaps less often as young get older. Young capable of flight at 28-32 days, may return to roost at nest site for several nights after fledging. One brood per year.

Young

Both parents care for and feed young. At some nests, one or two additional adults may help parents incubate eggs and feed nestlings. Feeding visits to nest are frequent: average once every 12-18 minutes, perhaps less often as young get older. Young capable of flight at 28-32 days, may return to roost at nest site for several nights after fledging. One brood per year.

Diet

Mostly flying insects. Feeds on a wide variety of flying insects, including flies, winged ants, bees, moths, beetles, mayflies, and others. Also some spiders and flightless insects.

Nesting

May nest as solitary pairs or in colonies. Courtship involves much aerial chasing, sometimes gliding with wings up in sharp V. Nest site is usually inside hollow tree, reached via broken-off top or woodpecker hole. Sometimes nests in chimneys. Both sexes gather nest material by breaking off small twigs from trees while flying. Twigs are carried in mouth to nest site, cemented into place with sticky saliva. Nest is a shallow half cup glued to inside wall of tree.