Royal tern
Royal tern | |
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Winter plumage | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Aves |
Order: | Charadriiformes |
Family: | Laridae |
Genus: | Thalasseus |
Species: | T. maximus
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Binomial name | |
Thalasseus maximus (Boddaert, 1783)
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Synonyms | |
Sterna maxima |
The royal tern (Thalasseus maximus) is a
Taxonomy
The royal tern was described by the French polymath
The generic name is derived from the Ancient Greek θάλασσα (thálassa) meaning "sea". The specific epithet maximus is Latin for "greatest".[8]
The royal tern belongs to the class
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 suggests that it is actually part of the genus Thalasseus.[9]
The West African crested tern (Thalasseus albididorsalis) was formerly considered to be a subspecies of royal tern. It was elevated to species status in January 2021.[10]
Description
This is a large tern, second only to the 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 upperparts, and white underparts. Its legs are black. In winter, the black cap becomes patchy.[11] 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 weight is anywhere from 350–450 g (12–16 oz).[12]
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 more melodious.[13]
In parts of its range, the royal tern could be confused with the elegant tern, 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
Behavior
Feeding
The royal tern typically feeds in small secluded bodies of water such as
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,crabs, and hatchling sea turtles.[2][15] 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.[2]
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.[14] 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.[2][16] 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.[14]
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.[17] 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 underwater. Animals such as foxes, raccoons, 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.[17][18]
A Tern was documented with a wing broken in three places near the launch site of the recent SpaceX Starship. A local vet at the zoo calls this a common injury. The bird was found 53 hours after the launch hurled concrete and rocks into the area. The Zoo vet says the injury could not have been caused by the debris, as the animal would have been removed by predators. This would have been the only bird alive injured after the launch. Reference injury report, 04/22/23 Brownsville Zoo.
Conservation
The
References
- ^ . Retrieved 19 November 2021.
- ^ a b c d e f g 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
- ^ Buffon, Georges-Louis Leclerc de (1781). "La grande hirondelle de mer de Cayenne". Histoire Naturelle des Oiseaux (in French). Vol. 16. Paris: De L'Imprimerie Royale. pp. 100–101.
- Daubenton, Louis-Jean-Marie (1765–1783). "Hirondelle de mer, de Cayenne". Planches Enluminées D'Histoire Naturelle. Vol. 10. Paris: De L'Imprimerie Royale. Plate 988.
- ^ Boddaert, Pieter (1783). Table des planches enluminéez d'histoire naturelle de M. D'Aubenton : avec les denominations de M.M. de Buffon, Brisson, Edwards, Linnaeus et Latham, precedé d'une notice des principaux ouvrages zoologiques enluminés (in French). Utrecht. p. 58, Number 988.
- ^ Boie, Friedrich (1822). "Generalübersicht". Isis von Oken (in German). Col 563.
- ^ Gill, Frank; Donsker, David, eds. (2019). "Noddies, gulls, terns, auks". World Bird List Version 9.2. International Ornithologists' Union. Retrieved 19 July 2019.
- ISBN 978-1-4081-2501-4.
- PMID 15804415.
- ^ Gill, F.; Donsker, D.; Rasmussen, P. (July 2020). "IOC World Bird List (v 10.2)". Retrieved 17 July 2020.
- ^ "Royal tern (Sterna maxima)". Planet of Birds]. Retrieved 17 November 2011.
- ^ "Royal Tern". All About Birds. Cornell Lab of Ornithology.
- ISBN 978-0-385-06806-2.
- ^ a b c Clay, Roger (October 2006). "Royal tern". Alabama Department of Conservation and Natural Resources. Archived from the original on 15 April 2012. Retrieved 7 November 2011.
- ^ Favero, Marco; Silva R., M. Patricia; Mauco, Laura (1 June 2000). "Diet of royal (Thalasseus Maximus) and sandwich (T. Sandvicensis) terns during the Austral winter in the Buenos Aires Province, Argentina" (PDF). Ornitologia Neotropical. 11: 259–262. Retrieved 7 November 2011.
- .
- ^ S2CID 130697581.
- ISSN 0749-0208.[permanent dead link]
External links
- "Royal Tern media". Internet Bird Collection.
- Royal tern photo gallery at VIREO (Drexel University)
- Royal Tern species account at Neotropical Birds (Cornell Lab of Ornithology)