Grallistrix

from Wikipedia, the free encyclopedia
Grallistrix
Systematics
Class : Birds (aves)
Order : Owls (Strigiformes)
Family : Real owls (Strigidae)
Subfamily : Striginae
Genre : Grallistrix
Scientific name
Grallistrix
Olson & James , 1991

Grallistrix is an extinct genus of real owls (Strigidae) that wasnativeto Hawaii in prehistoric times. It was described on the basis of subfossil skeletal finds and most likely shows similarity to the genus Strix . However, the members of Grallistrix had significantly longer legs, shorter wings and a leaner build. From their appearance also its scientific and English genus name ( "Stilt Owls") derive, both stilts owls mean.

The genus was endemic to the Hawaiian Islands and, in the absence of land mammals, fed on forest birds. It probably died out after the arrival of the Polynesians and the Pacific rat ( Rattus exulans ) that they introduced. Today four species are assigned to the genus, each of which was endemic to Kauai , Oʻahu , Molokai and Maui . The type species after which the genus was described is the Molokai long-legged owl ( Grallistrix geleches ).

features

The owls of the genus Gallistrix were roughly the same size as the tawny owl ( Strix aluco ). The wing bones were relatively small, but the legs were very long and muscular, even compared to large owls like the great gray owl ( Strix nebulosa ). The skull was very narrow for owls, as was the lower jaw.

Way of life

Dense forests, like here on Kaua'i , probably served as habitat for Grallistrix

The habitat of the Grallistrix species was probably dense forests, which explains their physique. Due to the lack of small mammals, they were dependent on small, diurnal, agile songbirds for food. Its morphological peculiarities - long legs and short, rounded wings - may have been an adaptation to hunting songbirds. The owls of the genus Mascarenotus , which were once also endemic to islands, and the forest harrier ( Circus dossenus ) also show a convergent development . Grallistrix species were likely ground-nesters, which made them particularly vulnerable when the Pacific rat ( Rattus exulans ) colonized Hawaii .

Systematics

In all likelihood, Grallistrix developed from the genus Strix , which has the strongest morphological similarities. All species come from a single colonization. Four species have been described for Gallistrix so far:

The Molokai long-legged owl was the largest, followed by the Kauai long-legged owl; the smallest species was the Maui long-legged owl, but it was only slightly smaller than its O'ahu cousin. The existence of four species in such a small area is remarkable, especially since four of the Hawaiian islands were connected as Maui Nui during the Pleistocene . The species may also have occurred sympatric , but so far there is no evidence for this.

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 0-19-854653-X
  • Alan C. Ziegler: Hawaiian natural history, ecology, and evolution. University of Hawaii Press, 2002. ISBN 0-8248-2190-4

Individual evidence

  1. ↑ 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 , pp. 68-72.
  2. ↑ a b Olson & James 1991, pp. 84-86.
  3. ↑ Pratt 2005, p. 44.
  4. ↑ Olson & James 1991, p. 76.
  5. ↑ Olson & James 1991, p. 81.