Strikingly long-winged and long-tailed elegant falcon with dark underwing coverts. Two plumage morphs: dark morph is uniformly dark while pale morph has white cheeks and a chestnut belly streaked with black. Juveniles resemble juvenile Eurasian Hobby but with contrasting underwing pattern. Graceful, relaxed flight may resemble a jaeger (skua), and is capable of similar turns of speed. Specializes on hunting migratory birds. Breeds on coastal cliffs and islands.