Haliastur
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Wedge-tailed harrier ( Haliastur sphenurus ) |
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| Selby , 1840 |
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Haliastur is a genus of birds of prey from the subfamily of the kites (Milvinae). The wedge-tailed Weih ( Haliastur sphenurus ) and Brahmin Weih ( Haliastur indus ) are only two species within the genus, all of which are medium-sized birds. The distribution area of the genus extends from the Indian subcontinent to New Caledonia off the East Australian coast.
The IUCN classifies the population situation of both species as harmless ( least concern ).
features
The two Haliastur species are medium-sized birds of prey with a strong, slightly squat rump, small head, relatively short and wide wings, a medium-long, rounded tail and short but strong legs and toes.
The wedge-tailed Weih reaches a body length of 50 to 60 centimeters and has a wingspan of 120 to 145 centimeters. Males weigh an average of 700 grams, the females are significantly heavier at 850 grams. The Brahmin consecration is a little smaller. Its body length is 44–52 cm, of which 18–22 cm are accounted for by the tail. The span is 110–125 cm. There is no sexual dimorphism in either species, but the females are slightly larger than the males in both species.
The wedge-tailed harrier has a sand-colored to brown plumage that is partially dashed. Young birds have only slightly different plumage than the adult birds. This is different with the Brahmin consecration. In adult birds of this species, the head, neck, chest and upper belly are white with a more or less distinct, fine, dark longitudinal stripe. The back, upper wing coverts, the upper side of the arm wings, the upper side of the inner wing wing and the basal half of the outer wing wing, the small and middle lower wing coverts, the lower abdomen and the leg fletching are dark rust-red. The young birds of this species are all in all almost monochrome, dark blackish gray-brown. The head, neck and the underside of the trunk are spotted and dashed lighter brown. They are thus similar to the adult wedge-tailed harriers and can be confused with each other during field observations.
Distribution area
The distribution area of the genus extends from the Indian subcontinent to New Caledonia and Tasmania.
The distribution area of the wedge-tailed Weih extends from Cenderawasih Bay in western New Guinea to Goodenough Island in the Solomon Sea off the east coast of New Guinea. The range also includes the Solomon Islands east of New Guinea and New Caledonia off the northeast coast of Australia. In Australia the wedge-tailed harrier is a very widespread species. It is only absent in parts of the Great Sand Desert . the Nullarbor Desert , the Great Victoria Desert, and the Gibson Desert . The distribution area of the Brahmin consecration includes large parts of the Indian subcontinent, Southeast Asia, New Guinea and the east and north of Australia.
food
The foraging for food in both species takes place predominantly in low gliding or rowing flight over water or land, but also often from a hide; less often on foot. Occasionally, the animals parasitize other small birds of prey, herons, gulls, crows or terns. The wedge tail also hunts food from the dingo .
Both species are omnivorous and the range of food available is correspondingly very large. The essential food components are often very different depending on the population. Both species feed on carrion of all kinds, such as leftovers and fishing waste, dead or sick fish , road victims and similar small carrion. The wedge tail can also be found on rubbish tips and slaughterhouses. In addition, a lot of live prey is hunted by both species, especially small fish and insects, but also crustaceans, small amphibians and reptiles, as well as mostly sick or injured small mammals and birds.
Reproduction
The reproductive biology of the two species has been studied differently.
At the Wedge Tail Fair, the previous knowledge was largely gained through captive birds. It is almost certainly a monogamous bird. However, there is no information on how long the pair bond exists in each case. The clutch of this species comprises one to three eggs, typically a clutch size of two eggs. Both parent birds breed, but the female's share in the breeding business is somewhat larger. In captivity, the incubation period is 35 days, outdoor observations suggest 38 to 40 days. Both parent birds feed and row the young birds. Nestlings grown up in captivity fledged between the 47th and 52nd day of life.
At the Brahmin consecration, the clutch consists of one to four eggs. The typical clutch size, however, is 2 eggs, as with the wedge-tailed harrier. They are incubated by both parent birds for 28–35 days. The young birds fly out after 40–56 days and are independent after about two months.
literature
- Bruce M. Beehler, Thane K. Pratt: Birds of New Guinea; Distribution, Taxonomy, and Systematics . Princeton University Press, Princeton 2016, ISBN 978-0-691-16424-3 .
- James Ferguson-Lees , David A. Christie: Raptors of the World. Helm Identification Guides, Christopher Helm, London 2001, ISBN 0-7136-8026-1 .
- PJ Higgins (Ed.): Handbook of Australian, New Zealand & Antarctic Birds , Volume 2, Raptors to Lapwings, Oxford University Press, Oxford 1993, ISBN 0-19-553069-1 .
Web links
Single receipts
- ↑ Handbook of the Birds of the World zum Keilschwanzweih , accessed on April 29, 2017
- ↑ Higgins (Ed.): Handbook of Australian, New Zealand & Antarctic Birds . Volume 2, p. 71.
- ^ J. Ferguson-Lees, DA Christie: Raptors of the World. Christopher Helm, London, 2001, ISBN 0-7136-8026-1 : p. 390.
- ↑ Higgins (Ed.): Handbook of Australian, New Zealand & Antarctic Birds . Volume 2, p. 72.
- ↑ Higgins (Ed.): Handbook of Australian, New Zealand & Antarctic Birds . Volume 2, p. 77.
- ↑ Higgins (Ed.): Handbook of Australian, New Zealand & Antarctic Birds . Volume 2, p. 78.