CSIRO PUBLISHING www.publish.csiro.au/journals/wr Wildlife Research, 2007, 34, 288–295 Time-budget and feeding behaviour of the squirrel glider (Petaurus norfolcensis) in remnant linear habitat Greg J. Holland A,C , Andrew F. Bennett A and Rodney van der Ree B A Landscape Ecology Research Group, School of Life and Environmental Sciences, Deakin University, 221 Burwood Highway, Burwood, Vic. 3125, Australia. B Australian Research Centre for Urban Ecology, Royal Botanic Gardens, Melbourne, c/- School of Botany, University of Melbourne, Vic. 3010, Australia. C Corresponding author. Email: ghol@deakin.edu.au Abstract. The squirrel glider (Petaurus norfolcensis) occurs in forests and woodlands in eastern Australia. In Victoria it is now largely restricted to small, fragmented areas and is considered endangered. In this study, the time-budget, feeding behaviour and related habitat use of the squirrel glider were investigated in a linear remnant of roadside vegetation near Euroa, Victoria. Timed observations of three males and three females, fitted with radio-collars, were made in each of four seasons. Gliders were observed for a total of 53.2h, during which they devoted 72% of time to foraging activities. Grooming accounted for 16% of observation time. Exudates associated with homopterous insects were the primary food items consumed throughout the year. Arthropods, nectar and pollen, and Acacia gum formed the remainder of the diet. The proportion of time devoted to harvesting these food items showed marked seasonal variation. The primary dependence on homopterous insect exudates in this study area contrasts with other investigations at sites of greater floristic diversity where nectar and pollen were the most important dietary resources. This highlights the need to obtain ecological information from the range of habitats occupied by a species. Large trees are a vital habitat component of remnant linear vegetation in this study area, providing gliders with critical foraging resources. Retention of such trees is essential for the longevity of glider populations. Introduction A fundamental process common to all living organisms is the attainment and consumption of energy. The time-budget of a species incorporates activities associated with this process, and identifies the relative importance of such activities by examining the proportion of time devoted to each. Time-budget information is useful for understanding how a species survives in a particular environment, and the resources it requires. Feeding is generally a significant component of time-budgets (e.g. Clarke et al. 1989; Goldingay 1989). Consequently, the type of dietary items consumed, and the availability and nutritional quality of such items, are likely to be significant influences and may cause both temporal and spatial variation in time- budgets (MacLennan 1984; Goldingay 1989; Comport et al. 1996). Studies that investigate both the time-budget and foraging ecology of a species are particularly useful as they not only elucidate activity patterns, but also identify possible processes behind such patterns. Foraging observations are also important in their own right given the fundamental significance of an animal’s diet and foraging behaviour to its ecology (Carr 1972; Owen 1980; Goldingay et al. 1991). The squirrel glider (Petaurus norfolcensis) is an arboreal, gliding marsupial distributed throughout eastern Australia (van der Ree and Suckling, in press). In the northern part of its range, the species is typically found in floristically diverse habitats ranging from dry sclerophyll forests to coastal wet forests (Quin 1995; Suckling 1995; Rowston 1998; Sharpe and Goldingay 1998). In south-eastern Australia, the squirrel glider is limited to dry open forests and woodlands that generally lack the mid- and upper-storey complexity and floristic diversity associated with its habitat further north (Menkhorst et al. 1988; Bennett et al. 1991; Menkhorst 1995). Such forests and woodlands have suffered large-scale clearing since European settlement. Areas that retain native vegetation are generally isolated to soils of low fertility, or occur as linear corridors along road reserves and drainage lines (Menkhorst et al. 1988; Menkhorst 1995; Environment Conservation Council 2001). It is these landscape features to which the squirrel glider is now largely restricted. As a result of this large-scale habitat reduction, small population sizes, and the threat of continued habitat loss, the squirrel glider is currently listed as ‘endangered’ in Victoria (Department of Sustainability and Environment 2003). Time-budget investigations of the yellow-bellied glider (Petaurus australis) (Goldingay 1989, 1990) and the mahogany glider (Petaurus gracilis) (Jackson and Johnson 2002) have revealed valuable insights into the ecology of these species. Such knowledge would be similarly valuable for the squirrel glider, but to date there are no published accounts of the time-budget of this species. The diet and foraging ecology of the squirrel glider has been documented in several studies (Menkhorst and Collier © CSIRO 2007 10.1071/WR06104 1036-9872/07/040288