Hook harrier
| Hook harrier | ||||||||||
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Hook harrier ( helicolestes hamatus ) |
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| Systematics | ||||||||||
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| Scientific name of the genus | ||||||||||
| Helicolestes | ||||||||||
| Bangs & Penard , 1918 | ||||||||||
| Scientific name of the species | ||||||||||
| Helicolestes hamatus | ||||||||||
| ( Temminck , 1821) |
The slender-billed kite ( Helicolestes hamatus ), sometimes analogous formerly known as the snails Milan called, is in the Neotropics native bird of prey - kind from the family of Accipitridae (Accipitridae). It is the only species of the hook harrier ( Helicolestes ) genus .
description
The hooked harrier is 35 to 41 centimeters long, with the females being about 2% larger than the males. It has a wingspan of 80 to 90 centimeters and a tail length of 11 to 14 centimeters. The wing length is 265 to 284 millimeters in the male and 272 to 288 millimeters in the female. The barrel is 41 to 46 millimeters long and the beak measures 29 to 35 millimeters. Males weigh 377 to 448 grams, females are slightly heavier at 367 to 485 grams. The plumage of the adult birds of both sexes is a single color, dark slate gray. The wings are relatively short and rounded at the ends. The tail end is straight. The iris is yellowish white. Wax skin and legs are orange, between the eye and the base of the beak there is an unfledged area which is also bright orange-red.
The young birds look quite similar to the adults. However, they are a bit lighter gray and the shoulder, wing and under tail coverts have dirty reddish brown to cream colored hems. In addition, the tail feathers show two white bands and a white end border.
The hooked harrier is characterized by a very long, thin and sickle-shaped curved upper beak, with which the main food - snails from the apple snail family - is extracted from the shell.
distribution and habitat
The hook harrier occurs from Panama , Colombia , Venezuela , French Guiana , Ecuador , Bolivia , Suriname to Brazil . Its habitat are forest swamps, shallow lagoons, floodplains from sea level up to 750 m. In Suriname it can occasionally be found in plantations.
Taxonomy
The hook harrier was often placed in the genus Rostrhamus until 2006 . After a taxonomic discussion, the genus Rostrhamus was split into the two monotypical genera Rostrhamus ( snail harrier ) and Helicolestes . The hook harrier was described by Coenraad Jacob Temminck in 1821 and assigned to the genus Rostrhamus by Richard Bowdler Sharpe in 1874 . In 1918 the ornithologists Outram Bangs and Thomas Edward Penard placed it in the new genus Helicolestes . In 1964, the American ornithologist Dean Amadon dissolved the genus Helicolestes and put the hook harrier back into the genus Rostrhamus . Due to the considerable differences between the two species, Amadon's revision was repeatedly criticized. For example, the hook harrier has a rapidly flapping wing beat, while the snail harrier flies slowly. The snail harrier is a sociable bird that breeds in colonies of up to 100 pairs, the hook harrier lives individually or in pairs. These criticisms were submitted to the South American Classification Committee of the American Ornithologists' Union , which placed the hook harrier back in the genus Helicolestes in 2006 .
literature
- James Ferguson-Lees , David A. Christie: Raptors of the World. Houghton Mifflin, Boston 2001, ISBN 0-618-12762-3 .
Web links
- Helicolestes hamatus in the Red List of Threatened Species of the IUCN 2008. Posted by: BirdLife International, 2008. Accessed January 18 of 2009.
- Resurrect the monotypic genus Helicolestes for the Slender-billed Kite
- A classification of the bird species of South America