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Red-billed Tropicbird | Phaethon aethereus
Roodsnavelkeerkringvogel | Rabijunco etéreo
The Red-billed Tropicbird is the largest of the three tropicbirds and in the Caribbean mainly a bird of the cliffs of the eastern islands. It flies high over the sea with fast, stiff wingbeats and plunges from a great height for flying fish and squid. Caribbean birds belong to the subspecies mesonauta. On English-speaking islands it is known as boatswain bird or bosun bird, in Puerto Rico as chirre.
Voice
At the colony and in display flight, loud rasping screams, often in a series, such as kreee-kreee-kri-kri-kri. Usually silent at sea.
Recording: Jesse Fagan — CC BY-NC-SA 4.0 · converted to mono · xeno-canto
Identification
90–105 cm including the long central tail feathers, which may reach 46–56 cm; the body measures about 48 cm. Adults are white with fine black barring on the back, scapulars and inner wing, giving the upperside a greyish look at close range. A black eye-stripe extends to the nape. The outer primaries and their coverts form a black wedge at the wingtip. The bill is red and the streamers white. Juveniles lack streamers and have a yellow bill, coarser barring, black tail tips and a black nuchal collar linking the eye-stripes behind the head.
Confusion species
White-tailed Tropicbird Phaethon lepturus is smaller and slimmer, with an unbarred white back, a yellow to orange bill and a black diagonal bar across the inner wing. Juvenile White-tailed lacks the black nuchal collar. Terns such as Royal Tern Thalasseus maximus have a forked tail without streamers, a black cap and a different, more flexible flight.
Habitat
Breeds on steep cliffs and rocky islets with crevices, holes and overhanging boulders, laying its single egg on bare ground. Forages over open sea, sometimes far offshore, plunge-diving for flying fish and squid. Small groups perform noisy display flights above the breeding cliffs.
Where the bird is most at home, classified by the vegetation types of the Caribbean.
Range and movements
Breeds in the Virgin Islands, on the islets east of Puerto Rico and across much of the Lesser Antilles, with important colonies on Saba and Sint Eustatius, south to the Grenadines, Grenada and Tobago (including Little Tobago). Scarce to rare around Puerto Rico, Hispaniola, Jamaica, Cuba and the Bahamas. Outside the region in tropical parts of the Atlantic, the eastern Pacific, the Red Sea, the Persian Gulf and the north-western Indian Ocean.
- Resident
- Summer visitor (c. Oct–Mar)
- Winter visitor (c. Apr–Sep)
- Passage (Mar–Apr, Oct–Nov)
- dark = core range, pale = thinly spread
How and when to look
Best seen from cliffs and headlands near known colonies, such as on Saba and Little Tobago, or from inter-island ferries. Calling display flights over the rocks are seen mainly in the breeding season, which falls largely in winter and spring. In juveniles, bill colour and the nuchal collar are the key features.
Conservation status
Not threatened, but probably declining globally. At breeding sites introduced rats, cats and other predators threaten eggs and chicks, and locally disturbance and the taking of eggs and young play a part.
Scientific name
Phaethon aethereus | Linnaeus, 1758
Linnaeus described the species in 1758 and placed it straight away in the genus where it still stands. He introduced the genus Phaethon in that same work. Phaethon goes back to the Greek phaethon 'sun, the shining one'. aethereus is Latin for 'heavenly', from aether 'the high, clear air'. The specimen the first description was based on came from Ascension Island.