Alternative name: Boatswain Bird
Includes: Arabian Tropicbird / Lesser Red-billed Tropicbird
- Phaethon aethereus
90–107 cm (35½-42 in), including tail streamers
- central tail feathers white, very long: can give bird total length of 96 cm
- upperside primary coverts and leading vanes of outer primaries black—giving a more or less solid black wedge at leading edge of wing
- rest of flight feathers white or with a pronounced black bar on the secondary coverts (indicus)
- back, mantle and lesser coverts with fine black or dark grey vermiculations on a white background
- eye patch black and usually pronounced (reduced in indicus). Tends to extend oliquely upwards behind the eye
- bill red, or ranging from pinky-orange to red (indicus)
Sexes are similar; males average longer-tailed
- tail streamers lacking
- back greyer
- bill yellow
Found in tropical waters of the Atlantic Ocean, the north-west Indian Ocean and the eastern Pacific.
They breed in the Galapagos Islands, Ecuador, off the Pacific coast of Mexico, in the Caribbean, the Canary Islands, Spain, on islands in the southern Atlantic, and the Yemen, Oman and Saudi Arabian coasts.
Subspecies indicus may be split as "Arabian Tropicbird" or "Lesser Red-billed Tropicbird", P. indicus based on plumage and vocal differences.
Clements recognises the following subspecies :
- P. a. mesonauta: Subtropical and tropical eastern Pacific, Caribbean and eastern Atlantic
- P. a. aethereus: Fernando de Noronha, Ascension Island and St Helena (south Atlantic)
- P. a. indicus: "Arabian Tropicbird". Red Sea, Persian Gulf and Gulf of Aden. [The shortest tail of any tropicbird, rarely as long as the body. Bill often pinkish or orangy with black cutting edges. Secondary coverts with (second) black bar. Black eye patch generally much reduced. Back vermiculations heavy, pronounced.]
Tropical islands, coastal cliffs and maritime.
Reported to not be a good swimmer.
They breed on tropical islands, laying a single egg on cliff ledges or on the ground.
They feed on fish and squid.
- Clements, J. F., T. S. Schulenberg, M. J. Iliff, D. Roberson, T. A. Fredericks, B. L. Sullivan, and C. L. Wood. 2017. The eBird/Clements checklist of birds of the world: v2017, with updates to August 2017. Downloaded from http://www.birds.cornell.edu/clementschecklist/download/
- BirdLife International
- BirdForum Opus contributors. (2023) Red-billed Tropicbird. In: BirdForum, the forum for wild birds and birding. Retrieved 28 November 2023 from https://www.birdforum.net/opus/Red-billed_Tropicbird