Sterna maxima

The royal tern (Thalasseus maximus) is a tern in the family Laridae. This bird has two distinctive subspecies: T. m. maximus which lives on the Atlantic and Pacific coasts of the North and South America, and the slightly smaller T. m. albididorsalis which lives on the coast of West Africa. The royal tern has a red-orange bill and a black cap during the breeding season, but in the winter the cap becomes patchy. The royal tern is found in Europe, Africa, the Americas, and the Caribbean islands. The royal tern lives on the coast and is only found near salt water. They tend to feed near the shore, close to the beach or in backwater bays. The royal tern's conservation status is listed as of least concern. The royal tern was described by the French polymath Georges-Louis Leclerc, Comte de Buffon in 1781 in his Histoire Naturelle des Oiseaux from a specimen collected in Cayenne, French Guiana. The bird was also illustrated in a hand-coloured plate engraved by François-Nicolas Martinet in the Planches Enluminées D'Histoire Naturelle which was produced under the supervision of Edme-Louis Daubenton to accompany Buffon's text. Neither the plate caption nor Buffon's description included a scientific name but in 1783 the Dutch naturalist Pieter Boddaert coined the binomial name Sterna maxima in his catalogue of the Planches Enluminées. The royal tern is now placed in the genus Thalasseus that was erected by the German zoologist Friedrich Boie in 1822. The generic name is derived from the Ancient Greek Thalassa meaning 'sea'. The specific epithet maximus is Latin for 'greatest'. The royal tern belongs to the class Aves and the order Charadriiformes. Charadriiformes are mainly seabirds of small to medium-large size. The royal tern is also in the family Sternidae because of its white plumage, black cap on its head, long bill, webbed feet, and bodies that are more streamlined than those of gulls. The taxonomy of the royal tern has been debated, whether the correct scientific name was Thalasseus maximus or Sterna maxima. It is presently classified as Thalasseus maximus, which places it with six other seabirds from the tern family. The royal tern was originally placed in the genus Sterna; however, a 2005 study suggest that it is actually part of the genus Thalasseus. It was suspected by wildlife conservationists in The Gambia that the West African birds were a separate species and analysis of DNA by scientists at the University of Aberdeen and the University of Montpellier have confirmed that the West African albididorsalis is a separate species. Feathers and other remains were collected from Mauritania and from islands off Tanji Bird Reserve, The Gambia and the DNA sequences shows the West African royal tern is closer to the lesser crested tern (Thalasseus bengalensis) than royal terns on the other side of the Atlantic. Two subspecies are recognised: This is a large tern, second only to Caspian tern but is unlikely to be confused with the carrot-billed giant, which has extensive dark under wing patches. The royal tern has an orange-red bill, pale grey upper parts and white under parts. Its legs are black. In winter, the black cap becomes patchy. Juvenile royal terns are similar to non-breeding adults. Differences include juveniles having black splotched wings and a yellower bill. An adult royal tern has an average wingspan of 130 cm (51 in), for both sexes, but their wingspan can range from 125–135 cm (49–53 in). The royal tern's length ranges from 45–50 cm (18–20 in) and their average weight is anywhere from 350–450 g (12–16 oz).