AskDefine | Define tern

Dictionary Definition

tern n : small slender gull having narrow wings and a forked tail

User Contributed Dictionary

English

Pronunciation

Etymology 1

From a Scandinavian language, related to Danish terne, Swedish tärna, ultimately from þerna.

Noun

  1. Any of various sea birds of the family Sternidae that are similar to gulls but are smaller, more elegant and have a forked tail.

Translations

Extensive Definition

Terns are seabirds in the family Sternidae, previously considered a subfamily (Sterninae) of the gull family Laridae (van Tuinen et al., 2004). They form a lineage with the gulls and skimmers which in turn is related to skuas and auks. Terns have a worldwide distribution.
Most terns were formerly treated as belonging into one large genus Sterna, with the other genera being small, but analysis of DNA sequences supports the splitting of Sterna into several smaller genera (see list, below) (del Hoyo et al., 1996; Bridge et al. 2005; Collinson 2006).
Many terns breeding in temperate zones are long-distance migrants, and the Arctic Tern probably sees more daylight than any other creature, since it migrates from its northern breeding grounds to Antarctic waters. One Arctic Tern, ringed as a chick (not yet able to fly) on the Farne Islands off the Northumberland coast in eastern Great Britain in summer 1982, reached Melbourne, Australia in October 1982, a sea journey of over 22,000 km (14,000 statute miles) in just three months from fledging—an average of over 240 km per day, and one of the longest journeys ever recorded for a bird.
They are in general medium to large birds, typically with grey or white plumage, often with black markings on the head. They have longish bills and webbed feet. They are lighter bodied and more streamlined than gulls, and look elegant in flight with long tails and long narrow wings. Terns in the genus Sterna have deeply forked tails, those in Chlidonias and Larosterna shallowly forked tails, while the noddies (genera Anous, Procelsterna, Gygis) have unusual 'notched wedge' shaped tails, the longest tail feathers being the middle-outer, not the central nor the outermost. Terns ranges in size from the Least Tern, at 42 g (1.5 oz) and 23 cm (9 inches), to the Caspian Tern, at 630 g (1.4 lbs) and 53 cm (21 inches).
Most terns (Sterna and the noddies) hunt fish by diving, often hovering first, but the marsh terns (Chlidonias) pick insects of the surface of fresh water. Terns only glide infrequently; a few species, notably Sooty Tern, will soar high above the sea. Apart from bathing, they only rarely swim, despite having webbed feet.
Terns are generally long-lived birds, with several species now known to live in excess of 25-30 years.

Classification and species list

A recent study (Thomas et al., 2004) of part of the cyt b gene sequence found a closer relationship between terns and the Thinocori, some species of aberrant waders. These results are in disagreement with other molecular and morphological studies (see Paton & Baker, 2006) and are best interpreted to prove an extraordinary amount of molecular convergent evolution between the terns and these waders, or as retention of an ancient genotype.
According the mtDNA studies and review by Bridge et al (2005), the genera and species of terns are as follows:
  • Genus Hydroprogne - Caspian Tern
  • Genus Larosterna - Inca Tern

References

  • 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.
  • del Hoyo, J.; Elliott, A. & Sargatal, J. (editors) (1996): Handbook of Birds of the World, Volume 3: Hoatzin to Auks. Lynx Edicions, Barcelona. ISBN 84-87334-22-9
  • Paton, Tara A. & Baker, Allan J. (2006): Sequences from 14 mitochondrial genes provide a well-supported phylogeny of the Charadriiform birds congruent with the nuclear RAG-1 tree. Molecular Phylogenetics and Evolution 39(3): 657–667. (HTML abstract)
  • Thomas, Gavin H.; Wills, Matthew A. & Székely, Tamás (2004a): Phylogeny of shorebirds, gulls, and alcids (Aves: Charadrii) from the cytochrome-b gene: parsimony, Bayesian inference, minimum evolution, and quartet puzzling. Molecular Phylogenetics and Evolution'' 30(3): 516-526. (HTML abstract)
  • van Tuinen, Marcel; Waterhouse, David & Dyke, Gareth J. (2004): Avian molecular systematics on the rebound: a fresh look at modern shorebird phylogenetic relationships. Journal of Avian Biology 35(3): 191-194. PDF fulltext

External links

tern in Arabic: خطاف البحر
tern in Catalan: Estèrnid
tern in Danish: Terner
tern in German: Seeschwalben
tern in Spanish: Sternidae
tern in Esperanto: Ŝterno
tern in French: Sternini
tern in Scottish Gaelic: Steàrnan
tern in Italian: Sternidae
tern in Hebrew: שחפיתיים
tern in Swahili (macrolanguage): Buabua
tern in Lithuanian: Žuvėdriniai
tern in Hungarian: Csérfélék
tern in Dutch: Sterns
tern in Japanese: アジサシ族 (Sibley)
tern in Norwegian: Terner
tern in Norwegian Nynorsk: Ternefamilien
tern in Polish: Rybitwy
tern in Portuguese: Sternidae
tern in Russian: Крачковые
tern in Scots: Tarn
tern in Finnish: Tiirat
tern in Swedish: Tärnor
tern in Tonga (Tonga Islands): Tala
tern in Turkish: Sumrugiller
tern in Ukrainian: Крячкові
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