Bill stout, slightly curved throughout, the margins finely serrated. Wings very long, 1st primary longest. Middle pair of tail-feathers excessively elongated and attenuated. Tarsus very short.
Four or five species are known, of which three have been recorded from Indian seas.
Key to the Species.
a. Outer web of first primary black.
a1. Hack barred in adults; white tips to first primary very narrow Tail-feathers 14……………………P. indicus, p. 349.
b1. Back quite white in adults; white tip to first primary more than 0.5 in. long Tail-feathers 12……………………P. flavirostris, p. 350.
b. Outer web of first primary white. Tail-feathers 10……………………P. rubricauda, p. 350.
The Tropic-birds, called by sailors Boatswain (Bosun) Birds, because, it is said, the long median tail-feathers recall the Boatswain's marling-spike, are truly oceanic, and are commonly seen at a distance from land, where they attract attention by their habit of flying up to ships, hovering round the masts, and sometimes resting on the masthead. They have a swift and elegant flight, and are often seen with their bills pointed downward, but: they turn their heads in various directions, sideways and even backward when flying. Their visits to ships appear due to curiosity, anything serves to attract them, and the firing of a gun will often bring them from a considerable distance. They feed on fish captured on the surface. They breed on oceanic islands, chiefly in holes of rocks, laying a single egg, pinkish-white in colour, mottled, spotted, and smeared with brownish purple.