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Royal Tern | Thalasseus maximus
Koningsstern | Charrán real
The Royal Tern is the large crested tern seen along almost every coast in the Caribbean: resting on jetties, buoys and sandbars, or fishing in bays and harbours. It is the most widespread large tern in the region. The West African birds formerly included in this species have been treated since 2020 as a separate species, West African Crested Tern Thalasseus albididorsalis.
Voice
A loud, rolling kee-rr or keer-rup, lower and less grating than the call of Sandwich Tern; also a more melodious, whistled tourrr-ee.
Recording: David Darrell-Lambert — CC BY-NC-SA 4.0 · converted to mono · xeno-canto
Identification
45–50 cm, large and powerful, with long, narrow wings, a forked tail and a thick, straight, orange to orange-red bill. In breeding plumage there is a black cap with a short, shaggy crest; this plumage is held only briefly, and for most of the year the forehead is white and the black is reduced to a shaggy fringe around the hindcrown that does not enclose the eye. Upperparts pale grey, underparts white. In flight the primaries are mostly pale below, with a narrow dark trailing edge. The legs are black. Juveniles have a paler, yellow-orange bill, dark spots on the wings and a dark bar across the secondary coverts.
Confusion species
Caspian Tern Hydroprogne caspia is heavier, with a thick, deep red bill, a darker, streaked cap even in winter and dark undersides to the primaries. Sandwich Tern Thalasseus sandvicensis is smaller and slimmer; its Cayenne form also has a yellow bill, but it is thinner and more pointed. Elegant Tern Thalasseus elegans, a very rare vagrant, is smaller, with a longer, thin, slightly drooping bill and a longer crest.
Habitat
Coastal waters, shallow bays, lagoons, harbours and estuaries; less often far out at sea. It fishes by plunge-diving from a greater height than Sandwich Tern. It rests in flocks on sandbars, beaches, quays, jetties and buoys. It breeds in dense colonies on bare islets and coral cays, often together with Sandwich Terns.
Where the bird is most at home, classified by the vegetation types of the Caribbean.
Range and movements
Seen throughout the region, from the Bahamas and the Turks and Caicos Islands through Cuba, the Cayman Islands, Jamaica, Hispaniola and Puerto Rico to the Virgin Islands, all of the Lesser Antilles, the ABC Islands, San Andrés and Trinidad and Tobago. Breeds locally on small islets, including in the Bahamas, on Cuba, in the Virgin Islands, the northern Lesser Antilles and on the reef islets of Aruba. Outside the region it breeds along the Atlantic and Pacific coasts of the United States and Mexico and along the coasts of South America to Argentina.
- 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
Almost any harbour, quay or sandbar along the coast is worth checking, and resting flocks can often be studied at close range. Elegant, Caspian and Cayenne Terns may be found among them; comparing bill shape and colour within such a flock is the best practice.
Conservation status
Not threatened. The species is numerous and widespread, but breeding colonies on low islets are vulnerable to disturbance, egg collecting, introduced rats and flooding during storms.
Scientific name
Thalasseus maximus | (Boddaert, 1783)
Boddaert described the species in 1783 as Sterna maxima; because it was later moved to another genus, the author and year stand in brackets. The genus Thalasseus was introduced in 1822 by Boie. Thalasseus derives from Ancient Greek thalassa 'sea'. maximus is Latin for 'greatest, largest'; it is one of the largest terns. The specimen the first description was based on came from Cayenne, French Guiana.