Sooty Tern

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Sooty Tern
Conservation status
Least concern (LC)
Scientific classification
Kingdom: Animalia Phylum: Chordata Class: Aves Order: Charadriiformes Family: Sternidae Genus: Onychoprion Species: O. fuscata
Binomial name
Onychoprion fuscata (Linnaeus, 1766)
Synonyms
Sterna fuscata Linnaeus, 1766

The Sooty Tern, Onychoprion fuscata - formerly Sterna fuscata (Bridge et al., 2005) - is a seabird of the tern family Sternidae. It is a bird of the tropical oceans, breeding on islands throughout the equatorial zone. This bird is migratory and dispersive, wintering more widely through the tropical oceans. It has very marine habits compared to most terns. This species is an extremely rare vagrant to western Europe, although a bird was present at Cemlyn Bay, Wales for 11 days in July 2005.

Sooty Tern breeds in colonies on rocky or coral islands. It nests in a ground scrape or hole and lays one to three eggs. It feeds by picking fish from the surface in marine environments, often in large flocks, and rarely comes to land except to breed, and can stay out to sea (either soaring or floating on the water) for between 3 to 10 years.

This is a large tern, similar to the Sandwich Tern in size at 33-36 cm in length and with an 82-94 cm wingspan. The wings and deeply forked tail are long, and it has dark grey upperparts and white underparts. It has black legs and bill. Juvenile Sooty Terns are scaly grey above and below. The call is a loud piercing ker-wack-a-wack or kvaark.

There are two similar races: O. f. fuscata of the Caribbean, Atlantic and west Africa has white underparts, whereas O. f. nubilosa, which breeds from the Red Sea to southeast Asia has a greyish tinge to the belly and underwing coverts in fresh plumage. Additional subspecies are recognized by various authors, but their status is very doubtful.

The Sooty Tern is unlikely to be confused with any tern apart from the similarly dark-backed but smaller Bridled Tern. It is darker-backed than that species, and has a broader white forehead and no pale neck collar.

[edit] Gallery

Under-wing

Rookery

Chick

[edit] References

• BirdLife International (2004). Sterna fuscata. 2006 IUCN Red List of Threatened Species. IUCN 2006. Retrieved on 11 May 2006. Database entry includes justification for why this species is of least concern
• 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
• 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