A slender, delicately built seabird with a straight, thin, pointed bill, long, pointed wings, and a very long, forked tail that extends beyond the wingtips when the bird is at rest. Juveniles have shorter tails than adults.
Relative Size
Larger than a Least Tern, smaller than a Sandwich or Royal Tern. Similar in size to Common Tern but with a longer tail.
Adults in breeding plumage are a shimmering chalky white overall, with pale gray upperwings, striking black cap, a blackish bill (mostly orange in Caribbean populations), and faintly rosy underparts. They have dark outer primaries and red legs. Nonbreeding adults have a white forehead and usually lack rosy tones. Juveniles are gray but scaly-looking above because of broad dark-gray tips to feathers.
Dives rapidly on prey from flight, either plunging just beneath the water to seize small fish or plucking prey without diving. Flight style and shape differs noticeably from other medium-sized terns, with long tail often readily apparent. Nests in colonies, usually among other tern species, and rests and forages in small flocks.
Nests on island beaches of sand, pebbles, or shells, often near low vegetation. Forages in ocean waters from coastlines to deep water.
Regional Differences
Ornithologists recognize three subspecies: dougalliiof the Atlantic Ocean and Caribbean Sea, the smallergracilisof most of the Indian Ocean, and korustes of the Indian Ocean around southern India and Sri Lanka, in which the bill is shorter and upperparts darker gray than in gracilis. Within the dougallii subspecies, individuals that breed in the Northeast have black bills that become red at the base through June and July. In Caribbean birds, the bill is one-third to one-half orange-red for most of the year, becoming mostly orange-red during June and July.