Elegant tern
| Elegant tern | |
|---|---|
| |
| Displaying birds at Upper Newport Bay, California | |
Scientific classification 
| |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Aves |
| Order: | Charadriiformes |
| Family: | Laridae |
| Genus: | Thalasseus |
| Species: | T. elegans
|
| Binomial name | |
| Thalasseus elegans (Gambel, 1849)
| |
| |
| Synonyms | |
|
Sterna elegans Gambel, 1849 | |
The elegant tern (Thalasseus elegans) is a tern in the family Laridae. It breeds on the Pacific coast of southern California in the United States and western Mexico, and migrates south to Peru, Ecuador and Chile for the northern winter; in the late summer and fall, some also disperse north to Oregon and more rarely Washington.
This species breeds in very dense colonies on coasts and islands, including Isla Rasa[2] and Montague Island in Mexico,[3] and South Bay Salt Works (San Diego) and Bolsa Chica Ecological Reserve in California.[4] Exceptionally, in can occur as an accidental inland on suitable large freshwater lakes.[5]
The elegant tern feeds by plunge-diving for fish, almost invariably from the sea, like most Thalasseus terns. It usually dives directly, and not from the "stepped-hover" favored by the Arctic tern. The offering of fish by the male to the female is part of the courtship display.
This Pacific species has wandered to western Europe as a rare vagrant on a number of occasions. The first European record was at Carlingford Lough in County Down, Northern Ireland, in late June 1982.[6] It has nested in Spain,[7][6][8] and has interbred with a Sandwich tern in France.[6] There is also one record from Cape Town, South Africa, in January 2006, the first record for Africa.
Taxonomy and etymology
[edit]The current genus name is derived from Greek Thalassa, "sea", and elegans is Latin for "elegant, fine".[9] The genus was created when a 2005 study implied that the systematics of the terns needed review.[10]
The closest relative of the elegant tern is Cabot's tern T. acuflavidus, which breeds on the Atlantic coasts of the Americas; this species pair is then next most closely related to the Old World Sandwich tern.[11][12][13]
Identification
[edit]This is a medium-large tern, with a long, slender, slightly downcurved orange bill, pale gray upperparts and white underparts. It is 39–42 cm (15–17 in) long with an 76–81 cm (30–32 in) wingspan, and a weight of 190–325 g (6.7–11.5 oz).[14][15] Its legs are black. From late summer to winter, the forehead becomes white. Juvenile elegant terns have a scalier pale gray back. The call is a characteristic loud grating noise similar to other Thalasseus terns.
This bird can be confused with the royal tern, but the royal tern is larger and thicker-billed and shows more white on the forehead in winter.[16] Out of range, it can also be easily confused with the lesser crested tern. See also orange-billed tern, and the external link below.
This species is marginally paler above than the lesser crested tern with a white (not gray) rump, with a slightly longer, more slender bill with a different curve. The black of the crest that comes down from the crown extends through the eye, creating a small black "smudge" in front of the eye even in winter plumage. On royal terns, the black crest stops at the eye, while lesser crested tern has a less shaggy crest.
Ecology and conservation
[edit]The total population is around 90,000 pairs, with the majority on islets in the Gulf of California.[4] It nests in a ground scrape and lays one or two eggs. Unlike some of the smaller Sterna terns, it is not very aggressive toward potential predators, relying on the sheer density of the nests (often only 20–30 cm apart) and nesting close to other more aggressive species, such as Heermann's gulls, to avoid predation. However, Heermann's gulls do predate some eggs and chicks, though more significant predators are the much larger and more predatory western and yellow-footed gulls.[17]
In May 2021, 1500 nests with thousands of eggs were abandoned when a drone crash landed near the nesting colony in Bolsa Chica Ecological Reserve, scaring off 2,500 nesting elegant terns and leading to a catastrophic loss.[4]
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Winter plumage, Stinson Beach, California -
Fishing at Bolsa Chica Ecological Reserve, California -
Bolsa Chica Ecological Reserve, California
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References
[edit]- ^ BirdLife International (2020). "Thalasseus elegans". IUCN Red List of Threatened Species. 2020: e.T22694552A178970750. doi:10.2305/IUCN.UK.2020-3.RLTS.T22694552A178970750.en. Retrieved 19 November 2021.
- ^ "SDNHM - Isla Rasa".
- ^ "Searchable Ornithological Research Archive" (PDF). Archived from the original (PDF) on 16 June 2012. Retrieved 22 February 2009.
- ^ a b c "Elegant Terns expanding in California". Audubon California. 9 July 2015. Retrieved 8 February 2025. Cite error: The named reference "Audubon" was defined multiple times with different content (see the help page).
- ^ "Observations". iNaturalist. 19 March 2008. Retrieved 8 February 2025.
- ^ a b c Stoddart, Andy; Batty, Chris (2019). "The Elegant Tern in Britain and Europe". British Birds. 112 (2): 99–109.
- ^ Dufour, Paul; Pons, Jean-Marc; Collinson, J. Martin; Gernigon, Julien; Ignacio Dies, J.; Sourrouille, Patricia; Crochet, Pierre-André (2017). "Multilocus barcoding confirms the occurrence of Elegant Terns in Western Europe" (PDF). Journal of Ornithology. 158 (2): 351–361. doi:10.1007/s10336-016-1380-0. ISSN 2193-7192. Retrieved 8 February 2025.
- ^ José Ignacio Dies, Ana Abad & Miguel Chardí: First record of multiple Elegant Tern nests in Spain at birdguides.com (retrieved 17 August 2008)
- ^ Jobling, James A (2010). The Helm Dictionary of Scientific Bird Names. London: Christopher Helm. pp. 144, 383. ISBN 978-1-4081-2501-4.
- ^ Bridge, Eli S.; Jones, Andrew W.; Baker, Allan J. (2005). "A phylogenetic framework for the terns (Sternini) inferred from mtDNA sequences: implications for taxonomy and plumage evolution" (PDF). Molecular Phylogenetics and Evolution. 35 (2): 459–469. doi:10.1016/j.ympev.2004.12.010. PMID 15804415. Archived from the original (PDF) on 12 April 2016. Retrieved 12 September 2016.
- ^ Efe, M.A.; Tavares, E.S.; Baker, A.J.; Bonatto, S.L. (2009). "Multigene phylogeny and DNA barcoding indicate that the Sandwich Tern complex (Thalasseus sandvicensis, Laridae, Sternini) comprises two species". Molecular Phylogenetics and Evolution. 52 (1): 263–267. doi:10.1016/j.ympev.2009.03.030. PMID 19348954.
- ^ Collinson, J.M.; Dufour, P.; Hamza, A.A.; Lawrie, Y.; Elliott, M.; Barlow, C.; Crochet, P.-A. (2017). "When morphology is not reflected by molecular phylogeny: the case of three 'orange-billed terns' Thalasseus maximus, Thalasseus bergii and Thalasseus bengalensis (Charadriiformes: Laridae)". Biological Journal of the Linnean Society. 121 (2): 439–445. doi:10.1093/biolinnean/blw049. hdl:2164/10159.
- ^ Černý, David; Natale, Rossy (2022). "Comprehensive taxon sampling and vetted fossils help clarify the time tree of shorebirds (Aves, Charadriiformes)" (PDF). Molecular Phylogenetics and Evolution. 177: 107620. doi:10.1016/j.ympev.2022.107620. Retrieved 22 December 2024.
- ^ Oiseaux.net. "Sterne élégante - Thalasseus elegans - Elegant Tern". www.oiseaux.net. Retrieved 25 September 2020.
- ^ "Elegant Tern Identification, All About Birds, Cornell Lab of Ornithology". www.allaboutbirds.org. Retrieved 25 September 2020.
- ^ Unitt, Philip. "SDNHM Focus on Royal and Elegant Terns".
- ^ Hoyo, Josep del; Elliott, Andrew; Sargatal, Jordi (1992). Handbook of the Birds of the World: Hoatzin to auks (in German). Barcelona: Lynx edicions. ISBN 84-87334-20-2.
External links
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