Medium-sized swift, very similar to Common Swift, but is noticeably paler, especially against a dark background. Wings are narrower and very pointed and the tail is longer and more deeply forked than Common or Pallid Swifts. Pale throat patch not distinct and difficult to see. Flight is very fast, agile, and erratic. Gives a shrill, wheezy scream that “hiccups” at the end. Breeds primarily on Madeira and the Canary Islands, but may move to North Africa in winter.