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The impact of predation by the powerful owl, Ninox strenua , on a population of the greater glider, Petauroides volans
Author(s) -
KAVANAGH RODNEY P.
Publication year - 1988
Publication title -
australian journal of ecology
Language(s) - English
Resource type - Journals
eISSN - 1442-9993
pISSN - 0307-692X
DOI - 10.1111/j.1442-9993.1988.tb00992.x
Subject(s) - predation , arboreal locomotion , glider , foraging , population , range (aeronautics) , forage , ecology , home range , biology , geography , predator , zoology , habitat , demography , materials science , sociology , marine engineering , engineering , composite material
Powerful owls were frequently observed during a study of the ecology of a community of arboreal marsupials in south‐eastern New South Wales. For about 17 months the population of greater gliders in the 100 ha study area appeared to remain ‘stable’ at more than 80 individuals. In the following 46 months, the population declined to about one‐tenth of its previous level. The forest in the study area was unlogged and remained undisturbed during this period. The frequency of sightings of powerful owls holding captured greater gliders, and of observations on the ground of tails and bodies belonging to greater gliders, and the unaccountable disappearance of 9 out of 11 individually marked greater gliders in the study area, suggest that the observed decline in the population of greater gliders was due to predation by the powerful owl. Powerful owls were not detected in the study area during the first 12 months or the last 21 months of the study. It is suggested that powerful owls forage by concentrating their activities in pockets of their large home range until they reduce the populations of their preferred prey below limits where it becomes difficult to catch the remaining animals. If preferred prey are available elsewhere, powerful owls probably move their centres of foraging activity to these pockets and harvest them before moving on to the next pocket of their range.