Abstract for presentation at Biodiversity Extinction Crisis Conference - A Pacific Response

In Victoria, the four large forest owls are listed as threatened. These species require special consideration with a whole-of-landscape approach to their management and conservation. Forest owls have large home ranges and need hollow-bearing trees to support their nesting requirements and those of arboreal mammals, which can make up the majority of their diet. In managed forests, harvesting operations can deplete the elements of old-growth forest that are required by forest owls and their prey. However, retained patches of mature forest may provide hollows for nesting and regrowth areas may provide additional habitat and foraging opportunities. We have studied the occurrence and distribution of forest owls within a managed, mixed-eucalypt forest in central Gippsland, Victoria. The study area, Boola Boola State Forest, has been commercially harvested for over 100 years, and is now a mosaic of mature forest stands dispersed among regrowth areas of different ages. Sixteen study sites throughout the forest were surveyed on two occasions each in 2006 and 2007 using a call playback technique. Four owl species were recorded in the study area: Southern Boobook (Ninox novaeseelandiae), Powerful Owl (Ninox strenua), Sooty Owl (Tyto tenebricosa) and Barking Owl (Ninox connivens). Timber harvesting history and vegetation types surrounding each site and around the point location of each owl response were determined using GIS layers. The relationships of these landscape variables to the numbers of species and numbers of owl records are outlined. An intense fire burnt seven of the 16 study sites in December 2006. The effect of this fire on owl populations is described. Information gathered from this project will contribute to the development of appropriate policy for the management of large forest owls in harvested forests and areas affected by fire.