The bridled tern (''Onychoprion anaethetus'') 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 ' meaning "claw" or "nail", and , meaning "saw". The specific ''anaethetus'' means "senseless, stupid".

Description

This 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 The sooty tern (''Onychoprion fuscatus'') is a seabird in the family Laridae. It is a bird of the tropical oceans, returning to land only to breed on islands throughout the equatorial zone. Taxonomy The sooty tern was described by Carl Linnaeu ...

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

This bird is migratory and dispersive, wintering more widely through the tropical oceans. It has markedly marine habits compared to most terns. The Atlantic

subspecies In biological classification, subspecies is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (morphology), but that can successfully interbreed. Not all species ...

''melanopterus'' breeds in Mexico, the

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 ...

and west Africa; other races occur around the

Arabian Peninsula The Arabian Peninsula, (; ar, شِبْهُ الْجَزِيرَةِ الْعَرَبِيَّة, , "Arabian Peninsula" or , , "Island of the Arabs") or Arabia, is a peninsula of Western Asia, situated northeast of Africa on the Arabian Plate ...

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 The International Olympic Committee (IOC; french: link=no, Comité international olympique, ''CIO'') is a non-governmental sports organisation based in Lausanne, Switzerland. It is constituted in the form of an association under the Swiss ...

: *''O. a. melanopterus'' – ( Swainson, 1837):

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

This 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 Arctic tern (''Sterna paradisaea'') is a tern in the family Laridae. This bird has a circumpolar breeding distribution covering the Arctic and sub-Arctic regions of Europe (as far south as Brittany), Asia, and North America (as far south a ...

. The offering of fish by the male to the female is part of the courtship display.

Various views and plumages

File:Bridledtern1.jpg, In non-breeding plumage File:Bridled Tern.jpg, Bridled tern, at rookery File:bridled_tern.jpg, Juvenile on Lady Elliot Island, Queensland,

Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...

File:Bridled Tern flight LEI jan08.JPG, In flight Lady Elliot Island, Queensland,

File:Juvenile Bridled Tern Splashing.jpg, Juvenile bathing at Perth Zoo File:Bridled tern (Onychoprion anaethetus) Oct 2011 Karnataka Pelagic Udupi flight scape.jpg, Juvenile or adult with non-breeding plumage taking off from a sea debris perch during Pelagic expedition off coast of Malpe Bridled tern (Onychoprion anaethetus antarcticus) after dive composite.jpg, ''O. a. antarcticus'' after dive (composite) File:Bridled Tern from the Crossley ID Guide Britain and Ireland.jpg, ID composite File:Bridled Tern (Onychoprion anaethetus) with egg in nest under boardwalk steps at Penguin Island, November 2022 02.jpg, With egg in nest under boardwalk steps on

Penguin Island, Western Australia Penguin Island is a island off the coast near Perth, approximately from Shoalwater. It is home to a colony of approximately 250 little penguins, the largest population of the birds in Western Australia. Since 2007, the island had experienced ...

References

External links

Avibase
{{Taxonbar, from=Q28490

bridled tern The bridled tern (''Onychoprion anaethetus'') 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 ' meaning "claw" or "nail", and , meaning "saw". The specific ...

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