Oahu long-legged owl
| Oahu long-legged owl | ||||||||||||
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| Grallistrix orion | ||||||||||||
| Olson & James , 1991 |
The Oahu Langbeineule ( Stilt-owl Orion ) is an extinct owl art , on the Hawaiian island of O'ahu was located. It was rather small compared to most recent owl species, had relatively short wings and long legs, and was probably diurnal. Like other Grallistrix species, it probably laid its eggs in ground nests, and its food consisted of songbirds that it hunted in the dense rainforests of Oahu.
In the course of the colonization of Hawaii by the Polynesians, the Oahu long-legged owl died out, probably because their eggs were easy prey for the introduced rats and pigs. Remains of the owl were first discovered in 1982, and in 1991 it was described as a species.
anatomy
The Oahu long-legged owl differed greatly from the species of owl still alive today. This is particularly evident in their comparatively short wings, greatly elongated legs and exceptionally powerful toes. This anatomy did not allow fast flight over long distances, but enabled the Oahu long-legged owl to perform extremely agile flight maneuvers and to hunt flyable birds. This was supplemented by the anatomy of the skull, which was built elongated and in which the eye sockets were more laterally aligned. The Oahu long-legged owl resembled sparrows , but also resembled other species endemic to wooded islands such as the mascarene owls ( Mascarenotus ) or the wood harrier ( Circus dossenus ). Of the species of the genus Grallistrix , the Oahu long-legged owl is the second smallest, only the long-legged owl ( G. erdmani ) was even more delicate. Adult birds did not quite reach the size of a tawny owl ( Strix aluco ).
Ecology and diffusion
.JPG)
The morphology of the Oahu long-legged owl, as with all species in the genus, may have been an adaptation to their way of life and their prey. Mammals did not exist in the Hawaiian archipelago before the arrival of the Polynesians . A rich source of food, however, was probably provided by the numerous species of honeysuckle, which were diurnal and able to fly and also lived in dense rainforests. The body structure of all four Grallistrix species shows characteristics similar to those of sparrows ( Accipiter nisus ) and similar birds of prey that hunt songbirds.
Because they had no nest predators to fear, the Oahu long-legged owl was probably ground-breeder, which suggests shell finds in sand dunes. According to current knowledge, the species was only widespread on Oahu.
Systematics and research history
Subfossils of the Oahu long-legged owl were first discovered in 1982 by Storrs Lovejoy Olson and Helen Frances James and served as the basis for the description as a species. The terra typica is Barbers Point in the south of the island. The generic name Grallistrix means “stilt owl ”, the specific epithet orion refers to the mythological hunter Orion and alludes to the agile owl's hunting skills.
There is currently no DNA analysis available for the systematics of the genus. However, the spatial separation of their distribution areas by that of the Molokai long-legged owl ( G. geleches ) speaks against a closer relationship between the two small species G. orion and G. erdmani .
Sources and References
literature
- Storrs L. Olson , Helen F. James : Descriptions of thirty-two new Species of Birds from the Hawaiian Islands. In: Ornithological Monographs 45, June 1991. ISBN 0-935868-54-2 . (Available online as PDF )
- Harold Douglas Pratt : The Hawaiian honeycreepers: Drepanidinae. Oxford University Press, 2005. ISBN 019854653X
- Beth Slikas : Lessons from a rediscovered avifauna. In: The Auk 120, No. 4, 2003. pp. 953-960. doi : 10.1642 / 0004-8038 (2003) 120 [0953: HBLFAR] 2.0.CO; 2