Diet of a family of powerful owls (Ninox strenua) from Warrandyte, Victoria

The diet of a family of powerful owls living at Warrandyte State Park was examined by analysis of 631 regurgitated pellets collected over five years (1991 to 1995). Warrandyte State Park forms a riparian strip along the Yarra River and is 24 km north-east of Melbourne. The Park's habitat has been disturbed in the past and it is surrounded by housing, introduced pastures and orchards. Mammalian prey was found in 98%, birds in 2% and insects in 8% of the pellets. Of the mammals, common ringtail possums occurred most frequently in the pellets, with no seasonal differences in occurrence. In contrast, common brushtail possums (which were found in 29% of pellets with mammalian remains) and sugar gliders (7%) showed seasonal variation in occurrence. The majority of common brushtail possums taken as prey were less than one year old, however, 15% were adults. We conclude that powerful owls feed opportunistically on suitable arboreal marsupials including large common brushtail possums, and that at Warrandyte most prey taken are not dependent on hollows for nesting.