The lesser crested tern (Thalasseus bengalensis) is a tern in the family Laridae.

Etymology

The genus name is from Ancient Greek Thalasseus, "fisherman" from thalassa, "sea". The specific bengalensis means "of Bengal", the type locality, historically referring to Bangladesh and part of Northeast India.

Distribution

It breeds in subtropical coastal parts of the world mainly from the Red Sea across the Indian Ocean to the western Pacific, and Australia, with a significant population on the southern coast of the Mediterranean on two islands off the Libyan coast. It is an occasional vagrant to Europe, where it has been known to breed in pure and mixed (with Sandwich tern) pairs. The Australian birds are probably sedentary, but other populations are migratory, wintering south to South Africa.

Subspecies

This bird has three geographical subspecies, differing mainly in size and minor plumage details:

  • T. b. emigratus <small>(Neumann, 1934)</small>: breeding in the Mediterranean on islands off the coast of Libya, wintering West Africa. Pale grey above (only marginally darker than Sandwich tern); slightly larger.
  • T. b. bengalensis <small>(Lesson, 1831)</small>: northern Indian Ocean including the Red Sea and the Persian Gulf, wintering to South Africa. Medium-dark grey above; slightly smaller.
  • T. b. torresii <small>(Gould, 1843)</small>: Indonesia south to Queensland, Australia, wintering in the same area (birds breeding in the Persian Gulf were formerly also sometimes cited as this subspecies

The grey rump is a useful flight identification feature distinguishing it from the related species. The Elegant tern also differs in a slightly longer, slenderer bill, while Chinese crested tern differs in a black tip to the bill and Sandwich tern a black bill with a yellow tip.

Conservation

T. bengalensis is one of the species to which the Agreement on the Conservation of African-Eurasian Migratory Waterbirds (AEWA) applies, and one of 10 marine bird species listed in Mediterranean marine birds Action Plan.

In India the Lesser crested tern is protected in the PM Sayeed Marine Birds Conservation Reserve.

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File:Lesser crested Tern (Thalasseus bengalensis) in Algeria.jpg|T. b. emigratus, Algeria

File:Lesser Crested Tern manly.ogg|T. b. torresii at Manly Marina, SE Queensland, with crested and Caspian terns, silver gulls and pied oystercatcher

File:Lesser crested terns at Muzhappilangad beach.jpg|Lesser crested terns at Muzhappilangad beach

</gallery>

Notes

References

Further reading

  • Azafzaf, H., Etayeb, K. & Hamza, A. 2006: Report on the census of Lesser Crested Tern Sterna bengalensis in the Eastern coast of Libya. (1–7 August 2006). Unpublished report to Regional Activities Centre/Special Protected Areas (MAP/UNEP), Environment General Agency (Libya) and African-Eurasian Waterbird Agreement (UNEP/AEWA). 18 pp with map and four Appendices.
  • Baker N.E (1984). Lesser Crested Tern in Bengazi, Libya. Bull. Orn. Soc. Middle East.
  • Hamza, A., H. Azafzaf, N. Baccetti, E.M. Bourass, J. J.Borg, P. Defos du Rau, A. Saied, J. Sultana, M. Zenatello (2008) Report on census and ringing of Lesser Crested Tern in Libya (2-10 Aug. 2007), with a preliminary inventory of Libyan islands. UNEP-MAP-RAC/SPA and EGA. Tech. Report.
  • Moltoni E. (1938). Escursione ornitologica all'Isola degli Uccelli (Golfo della Gran Sirte, Cirenaica). Riv. Ital. Orn 8 : 1-16.
  • Lesser crested tern - Species text in The Atlas of Southern African Birds