Oriental tern
| Oriental tern | ||||||||||
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| Systematics | ||||||||||
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| Scientific name | ||||||||||
| Sternula saundersi | ||||||||||
| ( Hume , 1877) |
The oriental tern ( Sternula saundersi ) is a species of sea bird from the family of the tern (Sternidae). It was originally part of the genus Sterna , after a revision of the tern family, it was transferred to the genus Sternula in 2005 . The type epithet honors the British ornithologist Howard Saunders , who made important contributions to the systematics of the terns in the late 19th century.
features
The oriental tern reaches a size of 28 to 29 centimeters, a weight of 40 to 45 grams and a wingspan of 50 to 55 centimeters. It looks very similar to the little tern ( Sternula albifrons ). The oriental tern differs from it by its straight upper edge to the white forehead, whereby the white color does not reach behind the eyes, by the somewhat lighter gray upper side, which contrasts more with the black outer hand wings, and by the gray rump and gray coat. Legs and feet are dark yellow olive. The third and fourth outer hand wings are black with black shafts. In the plain dress the upper side is colored darker than in the brood dress. Apart from a darker band on the arm wings, the juvenile birds of the oriental tern resemble those of the little tern.
distribution and habitat
The breeding areas of the Oriental Tern are in the Red Sea to the north of Yanbu , south of Socotra , in the south of Somalia , on the coasts of Saudi Arabia and Oman , along the coasts of the Persian Gulf , east to eastern and northwestern India and eastern and western India north-western Sri Lanka , on the Addu Atoll in the Maldives and probably on the Amiranten and the Seychelles . The wintering areas extend from the Red Sea south to Tanzania and Madagascar , east to the Seychelles via India to the Malay Peninsula . The oriental tern inhabits coasts, estuaries and lagoons. It is rarely found inland.
Way of life
The diet of the oriental tern consists of small fish, crustaceans and molluscs . The oriental tern catches its prey by thrust diving, which is often preceded by long hovering rounds. Little data is available on reproductive behavior. In Karachi and Sri Lanka , the breeding season is in May. The oriental tern forms small breeding colonies in which the nests are 20 to 100 meters apart. The nesting sites are above the tide line or in the Wadden Sea and are preferably located on small, wind-piled sand hills around a plant or other object. The nest can also be in a hollow or in the track of an animal, it can be bare or lined with shell fragments or small pebbles. The clutch consists of two light-colored eggs.
hikes
The migration routes of the oriental tern have not yet been adequately researched. Outside the breeding season, the terns were found in the Red Sea north of the Gulf of Aqaba , south along the East African coast to northern Tanzania, in Madagascar, along the west coast of India, in Gujarat , in Mumbai , in the Laccadives and the Maldives, and in the Seychelles observed. In southern Thailand , on the Malay Peninsula and in the Strait of Malacca , the oriental tern has already been identified as a rare wanderer .
status
The IUCN classifies the oriental tern in the category “not endangered” (least concern). Information on their population size is not available. There are said to be between 130 and 150 couples in Iran. Due to its great resemblance to the little tern, the species is probably often overlooked. It appears to be very common in the Karachi region .
Individual evidence
- ↑ ES Bridge, AW Jones & AJ Baker: A phylogenetic framework for the terns (Sternini) inferred from mtDNA sequences: implications for taxonomy and plumage evolution. In: Molecular Phylogenetics and Evolution. 35, 2005, pp. 459-469. PDF full text ( memento from July 20, 2006 in the Internet Archive ).
literature
- Josep del Hoyo , Andrew Elliot, Jordi Sargatal: Handbook of the birds of the world. Volume 3: Hoatzin to Auks. Lynx Edicions, Barcelona 1996, ISBN 84-87334-20-2 .