Thin-billed curlew
| Thin-billed curlew | ||||||||
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Thin-billed curlew |
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| Numenius tenuirostris | ||||||||
| Vieillot , 1817 |
The thin-billed curlew ( Numenius tenuirostris ) is a monotypical species from the family of snipe birds. The species is one of the rarest in the West Palearctic and is classified by the IUCN as critically endangered . In the 19th century the curlew was still a regular occurrence in Central Europe, albeit rarely as a migrant and winter visitor. However, there has been little evidence left since the 1980s. Most come from Hungary, where a total of seven thin-billed curlews were observed between 1990 and 1999.
description
The thin-billed curlew reaches a body length between 36 and 41 centimeters and weighs between 255 and 360 grams. The wingspan is 80 to 92 centimeters. It is about the size of a whimbrel , but significantly slimmer. The plumage is reminiscent of a curlew , but the curlew is usually noticeably lighter and the beak is completely black. The beak is slimmer than most curlews and ends in a fine point. In the magnificent dress, the heart-shaped spots on the flanks are particularly noticeable. The outer hand wings are almost black and contrast strikingly with the white spotted inner wings and the large arm covers in flying birds.
The rump and the back are pure white, the tail is dark and banded in white. The legs are dark gray. The calls of the curlew are similar to those of the curlew, but they are slightly higher and shorter.
Distribution and population development
The thin-billed curlew was originally widespread in western Siberia in the moors on Irtysh and Ob . The only known breeding areas were in the Tara region about 250 kilometers north of Omsk , where the thin-billed curlews brooded between 1914 and 1924. The migratory routes lead from this region in a south-westerly direction into the Mediterranean, where the birds winter in an area that extends as far as Morocco. In small numbers, they probably winter in Iraq, the Persian Gulf and the Arabian Peninsula . Since the 1980s, wintering birds have only been observed in one place in Morocco. Five birds were seen there in 1986, four in 1988, three between 1989 and 1992, two in 1993 and 1994 and one in 1995. There have been no more observations since 1995.
It is not known in which region thin-billed curlews currently breed. Several attempts were made between 1990 and 2008 to locate these breeding areas, but without success. In the mid-1990s, between 50 and 270 individuals still existed. In May 1998 a young bird was seen in England, so it is certain that there were still breeding birds in 1997. In the Ukraine, four birds were seen in July and August 2003 and again in August 2004, with a high probability that they were thin-billed curlews. One sighting that was considered to be certain took place in March 2005 in Montenegro .
The cause of the sharp decline is the intensive hunting pursuit in the resting and wintering areas. Because of their close resemblance to other curlews, thin-billed curlews have a very high risk of being accidentally shot. Apparently, most important resting places in steppe areas and wetlands in the Mediterranean were also lost. It is also assumed that breeding areas were destroyed by converting them into arable land. The sharp decline in the population has probably also led to a collapse in the social structure.
Habitat and way of life
The thin-billed curlew breeds in extensive peat bogs, which are covered with sedges, marsh horsetail, dwarf birch and osier. Outside the breeding season, like the curlew, it can be found on tidal flats and in salt marshes and in freshwater wetlands. He was observed among other things in saline mugwort steppe, in samphire corridors and in fields.
The diet consists of insects, mollusks, crustaceans and worms. Due to the very slender beak, it was concluded that the species prefers smaller prey and looks for them in softer substrate than the curlew and the whimbrel. Very little is known about reproductive biology. Due to the few nests found, however, it is certain that thin-billed curlews breed in shallow ground nests. The clutch consists of four eggs. These are gray-olive, ocher or brown and have dark spots and spots.
supporting documents
literature
- Hans-Günther Bauer, Einhard Bezzel and Wolfgang Fiedler (eds.): The compendium of birds in Central Europe: Everything about biology, endangerment and protection. Volume 1: Nonpasseriformes - non-sparrow birds. Aula-Verlag Wiebelsheim, Wiesbaden 2005, ISBN 3-89104-647-2 .
- Peter Colston , Philip Burton: Limicolen - All European wader species, identifiers, flight images, biology, distribution. BlV Verlagsgesellschaft, Munich 1989, ISBN 3-405-13647-4
- Simon Delany, Derek Scott, Tim Dodman, David Stroud (Eds.): An Atlas of Wader Populations in Africa and Western Eurasia. Wetlands International , Wageningen 2009, ISBN 978-90-5882-047-1
Single receipts
- ↑ Hans-Günther Bauer, Einhard Bezzel and Wolfgang Fiedler (eds.): The compendium of birds in Central Europe: Everything about biology, endangerment and protection. Volume 1: Nonpasseriformes - non-sparrow birds. Aula-Verlag Wiebelsheim, Wiesbaden 2005, ISBN 3-89104-647-2 , p. 463.
- ↑ a b c Simon Delany, Derek Scott, Tim Dodman, David Stroud (eds.): An Atlas of Wader Populations in Africa and Western Eurasia. Wetlands International , Wageningen 2009, ISBN 978-90-5882-047-1 , p. 303.
- ↑ a b Delany et al., P. 305.
- ↑ Bauer et al., P. 464.
- ↑ a b Peter Colston, Philip Burton: Limicolen - All European wader species, identifiers, flight images, biology, distribution. BlV Verlagsgesellschaft, Munich 1989, ISBN 3-405-13647-4 , p. 184.
Web links
- Only known video
- Numenius tenuirostris onthe IUCN Red List of Threatened Species 2013.2. Listed by: BirdLife International, 2012. Retrieved January 14, 2014.