Small gray swift with a slightly paler rump and belly. Flight is fast but erratic, with the wings pushed forward. Only known nesting sites are in a few caves, but can be seen in flight over all habitats on the granitic islands of the Seychelles. The calls include high-pitched twitters and echolocation clicks. Usually easy to identify, as it is the only resident swift on the Seychelles. Vagrant swifts have longer wings and a longer, forked tail.