An aerial feeder that is typically found over highland forests in flocks of up to forty birds; sometimes feeds at lower altitudes, particularly during inclement weather. Its stubby dark-gray body and rapid, shallow wingbeats eliminates all swallows. The Short-tailed Swift is similar, but the Short-tailed Swift has a gray vent and gray rump, which contrasts more markedly against its dark body than Lesser Antillean Swift. Very rarely found when not flying. Call is a high, sharp twitter.