The royal tern (''Thalasseus maximus'') is a
tern
Terns are seabirds in the family Laridae that have a worldwide distribution and are normally found near the sea, rivers, or wetlands. Terns are treated as a subgroup of the family Laridae which includes gulls and skimmers and consists of e ...
in the family
Laridae
Laridae is a family of seabirds in the order Charadriiformes that includes the gulls, terns, skimmers and kittiwakes. It includes around 100 species arranged into 22 genera. They are an adaptable group of mostly aerial birds found worldwide.
T ...
. The species is
endemic
Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...
to the Americas, though strays have been identified in Europe.
[Buckley, P. A. and F. G. Buckley (2020). Royal Tern (Thalasseus maximus), version 1.0. In Birds of the World (S. M. Billerman, Editor). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bow.royter1.01 Retrieved April 17, 2021]
Taxonomy
The royal tern was described by the French polymath
Georges-Louis Leclerc, Comte de Buffon
Georges-Louis Leclerc, Comte de Buffon (; 7 September 1707 – 16 April 1788) was a French naturalist, mathematician, cosmologist, and encyclopédiste.
His works influenced the next two generations of naturalists, including two prominent Fr ...
in 1781 in his ''Histoire Naturelle des Oiseaux'' from a specimen collected in
Cayenne
Cayenne (; ; gcr, Kayenn) is the capital city of French Guiana, an overseas region and Overseas department, department of France located in South America. The city stands on a former island at the mouth of the Cayenne River on the Atlantic Oc ...
,
French Guiana
French Guiana ( or ; french: link=no, Guyane ; gcr, label=French Guianese Creole, Lagwiyann ) is an overseas departments and regions of France, overseas department/region and single territorial collectivity of France on the northern Atlantic ...
. The bird was also illustrated in a hand-coloured plate engraved by
François-Nicolas Martinet François-Nicolas Martinet (1731 - 1800) was a French engineer, engraver and naturalist.
Martinet engraved the plates for numerous works on natural history, especially ornithology. Notable in particular are those for ''l'Ornithologia, sive Synop ...
in the ''Planches Enluminées D'Histoire Naturelle'' which was produced under the supervision of
Edme-Louis Daubenton
Edme-Louis Daubenton (12 August 1730 – 12 December 1785) was a French naturalist.
Daubenton was the cousin of another French naturalist, Louis Jean-Marie Daubenton. Georges-Louis Leclerc, the Comte de Buffon engaged Edme-Louis Daubenton to su ...
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
Pieter Boddaert (1730 – 6 May 1795) was a Dutch physician and natural history, naturalist.
Early life, family and education
Boddaert was the son of a Middelburg jurist and poet by the same name (1694–1760). The younger Pieter obtained his M.D ...
coined the
binomial name
In taxonomy, binomial nomenclature ("two-term naming system"), also called nomenclature ("two-name naming system") or binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, bot ...
''Sterna maxima'' in his catalogue of the ''Planches Enluminées''. The royal tern is now placed in the
genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...
''
Thalasseus
''Thalasseus'', the crested terns, is a genus of eight species of terns in the family Laridae.
It has a worldwide distribution, and many of its species are abundant and well-known birds in their ranges. This genus had originally been created by ...
'' that was erected by the German zoologist
Friedrich Boie
Friedrich Boie (4 June 1789 – 3 March 1870) was a German entomologist, herpetologist, ornithologist, and lawyer.Beolens, Bo; Watkins, Michael; Grayson, Michael (2011). ''The Eponym Dictionary of Reptiles''. Baltimore: Johns Hopkins University ...
in 1822.
The generic name is derived from the
Ancient Greek
Ancient Greek includes the forms of the Greek language used in ancient Greece and the ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Dark Ages (), the Archaic peri ...
θάλασσα : ''thálassa'' meaning "sea". The specific epithet ''maximus'' is Latin for "greatest".
The royal tern belongs to the class
Aves
Birds are a group of warm-blooded vertebrates constituting the class Aves (), characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweigh ...
and the order
Charadriiformes
Charadriiformes (, from ''Charadrius'', the type genus of family Charadriidae) is a diverse order of small to medium-large birds. It includes about 390 species and has members in all parts of the world. Most charadriiform birds live near water an ...
. 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 seven other terns. The royal tern was originally placed in the genus ''Sterna''; however, a 2005 study suggest that it is actually part of the genus ''Thalasseus''.
[
The ]West African crested tern
The West African crested tern (''Thalasseus albididorsalis'') is a bird species in the family Laridae. Until 2020 it was considered a subspecies of the New World royal tern, ''Thalasseus maximus''.R. Terry Chesser, Shawn M. Billerman, Kevin J. B ...
(''Thalasseus albididorsalis'') was formerly considered to be a subspecies of royal tern. It was elevated to species status in January 2021.
Description
This is a large tern, second only to the Caspian tern
The Caspian tern (''Hydroprogne caspia'') is a species of tern, with a subcosmopolitan but scattered distribution. Despite its extensive range, it is monotypic of its genus, and has no accepted subspecies. The genus name is from Ancient Greek ' ...
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 , for both sexes, but their wingspan can range from . The royal tern's length ranges from and their weight is anywhere from .[
The calls of the royal tern are usually short, clear shrills. Some of the shrills sound like ''kree'' or ''tsirr''; the royal tern also has a more plover like whistle that is longer, rolling and is more melodious.][
In parts of its range, the royal tern could be confused with the ]elegant tern
The elegant tern (''Thalasseus elegans'') is a tern in the family Laridae. It breeds on the Pacific coasts of the southern United States and Mexico and winters south to Peru, Ecuador and Chile.
This species breeds in very dense colonies on coa ...
, but the elegant tern has a longer, more curved, bill and shows more white on the forehead in winter.
Distribution and habitat
The royal tern is found on both coasts of the Americas. In the east during the breeding season (April to July) it is primarily found from Texas to Virginia. There are scattered breeding records as far north as Long Island, New York
Long Island is a densely populated island in the southeastern region of the U.S. state of New York, part of the New York metropolitan area. With over 8 million people, Long Island is the most populous island in the United States and the 18th ...
, coastally as far south as French Guiana
French Guiana ( or ; french: link=no, Guyane ; gcr, label=French Guianese Creole, Lagwiyann ) is an overseas departments and regions of France, overseas department/region and single territorial collectivity of France on the northern Atlantic ...
, and on several Caribbean
The Caribbean (, ) ( es, El Caribe; french: la Caraïbe; ht, Karayib; nl, De Caraïben) is a region of the Americas that consists of the Caribbean Sea, its islands (some surrounded by the Caribbean Sea and some bordering both the Caribbean Se ...
islands. Isolated breeding sites have been found in Argentina. The wintering range in the east is from North Carolina
North Carolina () is a state in the Southeastern region of the United States. The state is the 28th largest and 9th-most populous of the United States. It is bordered by Virginia to the north, the Atlantic Ocean to the east, Georgia and So ...
south to Panama and the Guianas
The Guianas, sometimes called by the Spanish loan-word ''Guayanas'' (''Las Guayanas''), is a region in north-eastern South America which includes the following three territories:
* French Guiana, an overseas department and region of France
* ...
and throughout the Caribbean. The western population nests from California to Mexico and winters from California south to Peru. Argentinian breeders may disperse into Brazil.[
]
Behavior
Feeding
The royal tern typically feeds in small secluded bodies of water such as estuaries
An estuary is a partially enclosed coastal body of brackish water with one or more rivers or streams flowing into it, and with a free connection to the open sea. Estuaries form a transition zone between river environments and maritime environment ...
, mangroves
A mangrove is a shrub or tree that grows in coastal saline or brackish water. The term is also used for tropical coastal vegetation consisting of such species. Mangroves are taxonomically diverse, as a result of convergent evolution in several ...
, and lagoons. Also, but less frequently, the royal tern will hunt for fish in open water, typically within about of the shore. The royal tern feeds in salt water and on very rare occasions in fresh water. When feeding they fly long distances from the colony to forage.[ The royal tern feeds by diving into the water from heights near .][ They usually feed alone or in groups of two or three, but on occasion they feed in large groups when hunting large schools of fish.][
The royal tern usually feeds on small fish such as anchovies, weakfish, and croakers. Fish are their main source of food but they also eat insects, shrimp, and crabs.][ The royal tern feeds on small crabs, such as young blue crabs that swim near the surface of the water. When feeding on small crabs the royal tern does not use its normal plunge-dive technique, but instead uses short shallow dives so that they are concealed from their prey. The royal tern also uses this technique when hunting flying fish.][
]
Breeding
The royal tern nests on island beaches or isolated beaches with limited predators. It lays one or two eggs, usually in a scrape, an area on the ground where a tern has made a small hole to lay its eggs. In some cases, tern eggs are laid directly on the ground, not in a scrape. The eggs incubate from 25 to 30 days; after the eggs hatch the chicks remain in the scrape for about a week. About two weeks after hatching the chicks gather into groups called a crèche
Crèche or creche (from Latin ''cripia'' "crib, cradle") may refer to:
*Child care center, an organization of adults who take care of children in place of their parents
*Nativity scene, a group of figures arranged to represent the birth of Jesus ...
.[ When the chicks are in the crèche, they are primarily fed by their parents who recognize their offspring by their voice and looks. While the chicks are in the crèche, they usually roam freely around the colony. In a large colony there can be thousands of chicks in the crèche.][ When the chicks are a month old they fledge or start to fly. Royal terns mature around the age of 4 years, after which they build their own nests and reproduce.][
]
Threats
The royal tern has few predators when it is mature, but before the chicks hatch or while they are chicks the tern is threatened by humans, other animals, and the tides.[ Humans threaten terns by fishing and by disrupting the tern nesting sites. Fishing nets can catch a tern while it is diving, making it unable to feed or it may cause it to drown if it is caught under water. Animals such as foxes, raccoon, and large gulls prey on tern chicks and tern eggs.
Tern nesting sites can also be affected by the tides; if a tern colony has nested too close to the high tide mark a spring tide would flood the nesting site and kill the chicks and make unhatched eggs infertile.][
]
Conservation
The IUCN
The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of natu ...
has rated the royal tern as of Least Concern.
References
External links
*
*
*
{{Taxonbar, from=Q28423
royal tern
The royal tern (''Thalasseus maximus'') is a tern in the family Laridae. The species is endemic to the Americas, though strays have been identified in Europe.Buckley, P. A. and F. G. Buckley (2020). Royal Tern (Thalasseus maximus), version 1.0. ...
Royal tern
The royal tern (''Thalasseus maximus'') is a tern in the family Laridae. The species is endemic to the Americas, though strays have been identified in Europe.Buckley, P. A. and F. G. Buckley (2020). Royal Tern (Thalasseus maximus), version 1.0. ...
Birds of South America
Birds of the Caribbean
Birds of the Dominican Republic
Birds of Mexico
Native birds of the Eastern United States
Native birds of the Southeastern United States
Royal tern
The royal tern (''Thalasseus maximus'') is a tern in the family Laridae. The species is endemic to the Americas, though strays have been identified in Europe.Buckley, P. A. and F. G. Buckley (2020). Royal Tern (Thalasseus maximus), version 1.0. ...