- Bridled Tern
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Bridled Tern 
Adult on Lady Elliot Island, Australia Conservation status Scientific classification Kingdom: Animalia Phylum: Chordata Class: Aves Order: Charadriiformes Family: Sternidae Genus: Onychoprion Species: O. anaethetus Binomial name Onychoprion anaethetus
(Scopoli, 1786)Synonyms Sterna anaethetus Scopoli, 1786
The Bridled Tern (Onychoprion anaethetus, formerly Sterna anaethetus - see Bridge et al., 2005) is a seabird of the tern family Sternidae. It is a bird of the tropical oceans.
Contents
Description
In non-breeding plumage
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 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 melanopters breeds in Mexico, the Caribbean and west Africa; other races occur around the Arabia and in Southeast Asia and Australasia, but the exact number of valid subspecies is disputed. It is a rare vagrant to western Europe.
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 offering of fish by the male to the female is part of the courtship display.
Lady Elliot Island, Qld, AustraliaVarious views and plumages
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Bridled Tern, at rookery
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Juvenile on Lady Elliot Island, Queensland, Australia
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In flight Lady Elliot Island, Queensland, Australia
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Juveniles at Perth Zoo
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Juvenile bathing at Perth Zoo
References
- BirdLife International (2004). Sterna anaethetus. 2006. IUCN Red List of Threatened Species. IUCN 2006. www.iucnredlist.org. Retrieved on 9 May 2006.
- 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. Molecular Phylogenetics and Evolution 35: 459–469. PDF fulltext
- Bull, John L.; Farrand, John Jr.; Rayfield, Susan & National Audubon Society (1977): The Audubon Society field guide to North American birds, Eastern Region. Alfred A. Knopf, New York. ISBN 0-394-41405-5
- Collinson, M. (2006). Splitting headaches? Recent taxonomic changes affecting the British and Western Palaearctic lists. British Birds 99(6): 306-323.
- Olsen, Klaus Malling & Larsson, Hans (1995): Terns of Europe and North America. Christopher Helm, London. ISBN 0-7136-4056-1
External links
Categories:- IUCN Red List least concern species
- Birds of Puerto Rico
- Onychoprion
- Birds of Western Australia
- Birds of Southeast Asia
- Birds of Pakistan
- Birds of Mexico
- Birds of Africa
- Birds of South Africa
- Animals described in 1786
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