Stilt-owl
Grallistrix is an extinct genus of authentics owls ( Strigidae ), which was native to prehistoric times in Hawaii. It was described on the basis of subfossil skeletal remains and shows most similarity to the genus Strix. However, the members of Grallistrix had significantly longer legs, shorter wings and a leaner physique. From their appearance also their scientific and English common noun ( " Stilt Owls " ) derive that mean both stilt owls.
The genus was endemic to the Hawaiian Islands and fed in the absence of land mammals of forest birds. She probably died after the arrival of the Polynesians and by them dragged from the Pacific rat (Rattus exulans ). The genus four species are now attributed that were endemic each on Kauai, Oahu, Molokai and Maui. The type species, after which the genus was described, the Molokai - Langbeineule ( Grallistrix geleches ).
Features
The owls of the genus Gallistrix corresponded in body size in about the tawny owl (Strix aluco ). The wing bones were relatively small, the legs, however, were very long and muscular, even compared to large owls such as the great gray owl (Strix nebulosa ). The skull was very narrow for owls, as well as the lower jaw.
Way of life
The habitat of Grallistrix species were probably dense forests, which explains their physique. Because of the lack of small mammals they had to rely on small, diurnal, agile singing birds as food. Maybe put their morphological features - long legs and short, rounded wings - an adaptation to hunting songbirds represents a convergent evolution also show that once also endemic to islands owls of the genus Mascarenotus and the forest Harrier (Circus dossenus ). Grallistrix species were probably ground-nesting birds, which they made especially vulnerable in the colonization of Hawaii by the Pacific rat (Rattus exulans ).
System
In all probability Grallistrix developed in the genus Strix, which has the strongest morphological similarities. It all come from a single species Koloniasation. Far four species have been described for Gallistrix:
- Kauai Langbeineule (G. auceps ), Kauai
- Langbeineule (G. erdmani ), Maui
- Molokai Langbeineule (G. geleches ), Molokai
- Oahu Langbeineule (G. orion ), Oahu
The Molokai Langbeineule was the largest species, followed by Kauai Langbeineule; the smallest species was the Langbeineule of Maui, however, was only slightly smaller than their relatives of Oahu. Noteworthy is the existence of four species in such a small space, especially since four of the Hawaiian Islands were connected during the Pleistocene as Maui Nui. Perhaps the species occurred also sympatric, but it is currently missing documents.