The sooty tern (Onychoprion fuscatus) is a tern in the family Laridae. It is a seabird of the tropical oceans and can fly for years at a time, skimming the sea surface for food, and returning to land only to breed, on islands throughout the equatorial zone.

Taxonomy

The sooty tern was described by Carl Linnaeus in 1766 as Sterna fuscata, bearing this name for many years until the genus Sterna was split up; it is now classified in the genus Onychoprion as Onychoprion fuscatus. The genus name is from ancient Greek , "claw" or "nail", and , "saw". The species name fuscatus is Latin for "dark".

The sooty tern has little interspecific variation, but it is usually divided into six to eight allopatric subspecies. Some recent authors further subdivide the Indopacific population into up to eight subspecies altogether, but much of the variation is clinal. The affinities of eastern Pacific birds (including O. f. manutarus of Easter Island) are most strongly contested. Six subspecies are currently accepted by the IOC:

  • Onychoprion fuscatus infuscatus <small>(Lichtenstein, 1823)</small> – Sunda Islands and vicinity (included in O. f. nubilosus by IOC Juvenile sooty terns are grey-black above and below with narrow pale fringes on the upperpart feathers giving a scaly appearance above, and whitish on only the lower belly.

The sooty tern is unlikely to be confused with any tern apart from the similarly dark-backed but smaller bridled tern (O. anaethetus). It is darker-backed than that species, and has a broader white forehead and no pale neck collar.

The call is a loud piercing 'wide-a-wake', It nests in a ground scrape or hole and lays a single egg, typically in the afternoon. Although "two-egg clutches" have been reported, they probably occur when an egg from one nest rolls into another. 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 for 3 to 10 years. Due to the lack of oil in its feathers, it cannot float, and spends that entire time on the wing. This species is a rare vagrant to western Europe, although a bird was present at Cemlyn Bay, Wales for 11 days in July 2005.

It is also not normally found on the Pacific coasts of the Americas due to its pelagic habits. At Baja California, where several nesting locations are offshore, it can be seen more frequently, whereas for example only two individuals have ever been recorded on the coast of El Salvador - one ring recovered in 1972, and a bird photographed on October 10, 2001 at Lake Olomega<!-- source has only "Olomega"; possibly a village or minor settlement at the lake --> which was probably blown there by a storm.<!-- ref is for El Salvador only. Default ref for this paragraph would be HBW --> Hurricanes can also devastate small breeding colonies, as has been surmised for example for the sooty tern nesting sites on cays off the San Andrés Islands of Colombia.<!-- each reference in this paragraph refers to the preceding sentence ONLY - ref after punctuation will require generous use of to mark unreferenced bulk of para -->

An exceptionally common bird, the sooty tern is not considered threatened by the IUCN. In most of Polynesia its name is manutara or similar, literally "tern-bird", though it might be better rendered in English as "the tern" or "common tern". This refers to the fact that wherever Polynesian seafarers went on their long voyages, they usually would find these birds in astounding numbers. It is also known as kaveka in the Marquesas Islands, where dishes using its eggs are a delicacy.

On Easter Island, this species and the spectacled tern (O. lunatus) are collectively known as manutara. The manutara played an important role in the tangata manu ("birdman") ritual: whichever hopu (champion) could retrieve the first manutara egg from Motu Nui islet would become that year's tangata manu; his clan would receive prime access to resources, especially seabird eggs.

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Image:Sooty tern flying.JPG|Sooty tern colony on Tern Island (French Frigate Shoals)

Image:Sooty Tern chick.JPG|Chick on Tern Island, French Frigate Shoals

Image:BFAL SOTE shade.JPG|Sooty tern chicks seeking shade under the shadow of a young black-footed albatross

Image:Frigate sooty.JPG|A chick is snatched by a predatory great frigatebird

File:Onychoprion fuscatus -Phillip Island, Norfolk Island group, Australia -egg-8.jpg|Egg

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References

Sources

  • Boulton, Rudyerd & Rand, A.L. (1952): A collection of birds from Mount Cameroon. Fieldiana Zoology 34 (5): 35–64. Fulltext at the Internet Archive
  • Pukui, Mary Kawena; Elbert, Samuel Hoyt; Mookini, Esther T. & Nishizawa, Yu Mapuana (1992): New Pocket Hawaiian Dictionary with a Concise Grammars and Given Names in Hawaiian. University of Hawaii Press, Honolulu. <small></small>
  • Streets, Thomas H. (1877): Some Account of the Natural History of the Fanning Group of Islands. Am. Nat. 11 (2): 65–72. First page image
  • Tregear, Edward (1891): Maori-Polynesian Comparative Dictionary. Lyon and Blair, Wellington.

Further reading

  • Brown, William Yancey (1973). Breeding Biology of the Sooty Tern and Brown Noddy on Manana or Rabbit Island, Hawaii. Ph.D. Dissertation, University of Hawaii.[https://commons.wikimedia.org/wiki/File:Breeding_Biology_of_Sooty_Terns_and_Brown_Noddies_on_Manana_Istand,_Hawaii.pdf]
  • Olsen, Klaus Malling & Larsson, Hans (1995): Terns of Europe and North America. Christopher Helm, London. <small></small>
  • Sooty tern article at BirdNote.org ()
  • Sooty terns on Ascension Island South Atlantic ()