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The diet of a Southern Boobook Ninox novaeseelandiae in a Box-Ironbark woodland remnant in central Victoria was studied. An analysis of 42.5 pellets found invertebrates to represent 82% of the total prey items, but vertebrates, in the form of the House Mouse Mus domesticus, to represent 88% of the biomass. The proportion of spiders as prey items in the diet in this instance (43%) was significantly higher than in other studies on mainland Australia. The Creighton Hills woodland comprises ~130 ha of dry woodland/forest dominated by mainly regrowth Grey Box Eucalyptus microcarpa and Red Stringybark E. macrorhyncha, with smaller areas of Red Box E. polyanthemos and Blakely's Red Gum E. blakelyi. The woodland is largest remnant on the Longwood Plains, a heavily-cleared region in which only 5% of original vegetation remains (Ahern et al. 2003) (Fig. 2). However, the linear roadside and streamside vegetation present throughout the Longwood Plain (comprising Grey Box and River Red Gum E. camaldulensis respectively) is considered to be ecologically important in its own right (van der Ree and Bennett 2001). Boobooks are often heard calling in nearby roadsides and the bird may have been hunting in either the Creighton Hills woodland or the surrounding agricultural landscape.Pellets were analysed by ABR, and the minimum numbers of individual prey items determined, by counting skeletal parts and by comparison with reference material. ResultsThe 42 whole pellets measured 11-40 x 8-20 mm (mean 23.5 x 16.2 mm). Seventy-two individual prey items were recorded, comprising at least six distinct species (Table 1). Invertebrates constituted 82% of the prey items by number, with spiders (Araneae) representing 43% and beetles (Coleoptera) 29.2%. Wolf spiders (Lycosidae) were the most common prey item, representing 36.1% of the total prey individuals. House Mice Mus domesticus occurred in most pellets and represented 18.1% of the prey individuals identified. Some fragments of grass were also present in one pellet. By weight, House Mice contributed more than 88% of prey biomass, and spiders 6% (Table 1). DiscussionThe diet of the Southern Boobook at Creighton Hills consisted of mainly invertebrate prey (by number), although vertebrate prey represented a significant proportion of the total biomass. This broadly corresponds with studies elsewhere that invertebrates are the main prey item by number (e.g. Higgins 1999; Penck and Queale 2002). However, the results also support the findings by Olsen et al. (2006) and McNabb (2002) that the diet of Boobooks in south-eastern Australia is, by biomass, primarily vertebrates. The mean prey weight in this study is much lower than the mean prey weight in McNabb (2002) or Olsen et al. (2006) because the heaviest animal taken in this study was 17.5 g. The differences in the composition of prey items in Boobook dietary studies may in part reflect different methods of prey analysis and collecting prey remains (Olsen et al. 2006). For example, pellets were found to have proportionally less inve...