The bridled tern (Onychoprion anaethetus)[2][3][4] is a seabird of the family Laridae. It is a bird of the tropical oceans. The scientific name is from Ancient Greek. The genus comes from onux meaning "claw" or "nail", and prion, meaning "saw". The specific anaethetus means "senseless, stupid".[5]
| Bridled tern | |
|---|---|
| |
| Adult on Lady Elliot Island, Australia | |
Scientific classification 
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| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Aves |
| Order: | Charadriiformes |
| Family: | Laridae |
| Genus: | Onychoprion |
| Species: | O. anaethetus
|
| Binomial name | |
| Onychoprion anaethetus (Scopoli, 1786)
| |
| |
| Synonyms | |
|
Sterna anaethetus Scopoli, 1786 | |
Description
editThis is a medium-sized tern, at 30–32 cm in length and with a 77–81 cm wingspan similar to the common tern in size, but more heavily built. The wings and deeply forked tail are long, and it has dark grey upperparts and white underparts. The forehead and eyebrows are white, as is a striking collar on the hindneck. It has black legs and bill. Juvenile bridled terns are scaly grey above and pale below.
This species is unlikely to be confused with any tern apart from the similarly dark-backed sooty tern and the spectacled tern from the Tropical Pacific. It is paler-backed than that sooty, (but not as pale as the grey-backed) and has a narrower white forehead and a pale neck collar.
Distribution and movements
editThis bird is migratory and dispersive, wintering more widely through the tropical oceans. It has markedly marine habits compared to most terns. The Atlantic subspecies melanopterus breeds in Mexico, the Caribbean and west Africa; other races occur around the Arabian Peninsula and in Southeast Asia and Australasia, but the exact number of valid subspecies is disputed. It is a rare vagrant to western Europe. These are the four subspecies listed by the IOC:
- O. a. melanopterus – (Swainson, 1837): Caribbean and West Africa.
- O. a. antarcticus – (Lesson, 1831): Red Sea, Persian Gulf and western Indian Ocean.
- O. a. anaethetus – (Scopoli, 1786): eastern Indian, and Pacific Oceans.
- O. a. nelsoni – (Ridgway, 1919): west coast of Mexico and Central America.
Breeding
editThis species breeds in colonies on rocky islands. It nests in a ground scrape or hole and lays one egg. It feeds by plunge-diving for fish in marine environments, but will also pick from the surface like the black tern and the gull-billed tern. It usually dives directly, and not from the "stepped-hover" favoured by the Arctic tern. The offering of fish by the male to the female is part of the courtship display.
Various views and plumages
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In non-breeding plumage -
Bridled tern, at rookery -
Juvenile on Lady Elliot Island, Queensland, Australia -
In flight Lady Elliot Island, Queensland, Australia -
Juvenile bathing at Perth Zoo -
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O. a. antarcticus after dive (composite) -
ID composite -
With egg in nest under boardwalk steps on Penguin Island, Western Australia
_Oct_2011_Karnataka_Pelagic_Udupi_flight_scape.jpg)
_after_dive_composite.jpg)
_with_egg_in_nest_under_boardwalk_steps_at_Penguin_Island,_November_2022_02.jpg)
References
edit- ^ BirdLife International (2019). "Onychoprion anaethetus". IUCN Red List of Threatened Species. 2019: e.T22694730A154676367. doi:10.2305/IUCN.UK.2019-3.RLTS.T22694730A154676367.en. Retrieved 19 November 2021.
- ^ Scopoli, Giovanni Antonio (1786). Deliciae florae et faunae Insubricae. Vol. 2. Ticini: Ex Typographia Reg. & Imp. Monasterii S. Salvatoris. Praesidib. Rei litter. permittentibus. p. 92.
- ^ Bridge, E. S.; Jones, A. W.; Baker, A. 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. Bibcode:2005MolPE..35..459B. doi:10.1016/j.ympev.2004.12.010. PMID 15804415. Archived from the original (PDF) on 20 July 2006.
- ^ Sometimes the name is (wrongly?) spelled as S. anaestheta, for instance in: Saunders, Howard (1877). "On the Occurrence of the Smaller Sooty Tern at the Mouth of the Thames". The Zoologist. 3. 1: 213–216.
- ^ Jobling, James A (2010). The Helm Dictionary of Scientific Bird Names. London: Christopher Helm. pp. 46, 282. ISBN 978-1-4081-2501-4.
External links
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