Diet of an inland population of the common ringtail possum (Pseudocheirus peregrinus) Eden Hermsen A , Anne Kerle B and Julie M. Old A,C A Water and Wildlife Ecology Research Group, School of Science and Health, Hawkesbury, University of Western Sydney, Locked Bag 1797, Penrith, NSW 2751, Australia. B Fitzroy Street, Peel, NSW 2795, Australia. C Corresponding author. Email: j.old@uws.edu.au Abstract. Populations of the common ringtail possum (Pseudocheirus peregrinus) in inland New South Wales have declined or disappeared. Habitat requirements and diet of these populations are poorly understood. Determining the diet of inland ringtail possums is crucial to understanding the factors limiting their survival, and was the focus of this study. Spotlighting surveys were conducted to locate ringtail possums, and scat and vegetation samples were collected for microhistological analysis. Ringtail possums were most frequently observed in red stringybark followed by bundy box and black cypress pine trees, and this correlated with the most common dietary items consumed. Additional keywords: black cypress pine, bundy box, marsupial, microhistological analysis, red stringybark. Received 21 April 2015, accepted 15 October 2015, published online 17 November 2015 Introduction The common ringtail possum (Pseudocheirus peregrinus) (hereafter referred to as ringtail possum) occurs in eastern Australia. It is most abundant along the coastline, with scattered populations found inland on the slopes of the Great Dividing Range and the Murray and Murrumbidgee Rivers (Kerle 2004; BioNet 2014). Although considered common and of ‘least concern’, their distribution and abundance in inland New South Wales has been shown to have declined dramatically (Kerle 2004; Paull and Kerle 2004) and regional conservation strategies, including habitat conservation, are needed. Previous dietary analyses indicate that ringtail possums are strict herbivores and primarily folivores, feeding mainly on myrtaceous trees and shrubs, with Eucalyptus spp. being the most prominent (Thomson and Owen 1964; Pahl 1984, 1987; Hume et al. 1996). However, ringtail possum diets may be more generalised, with some populations feeding on leaves, shoots, buds, flowers or fruit of understorey vegetation. While key genera of potential food species occur across their range, available species differ and food preferences are unknown for ringtail possum populations in inland New South Wales. In this paper we provide a preliminary assessment of the dietary composition of a population of inland ringtail possums previously described at Black Rock Ridge, Orange, NSW (Kerle et al. 2013). Materials and methods Site description Black Rock Ridge (33  260 0 S, 148  520 0 E) is a sandstone ridge 8.5 km long and 1–2 km wide that rises steeply from 540 to 800 m above sea level. It covers 1030 ha on ‘Ulah’, a private property ~30 km south-west of Orange (Kerle et al. 2013). It is a remnant patch of native vegetation surrounded by grazed agricultural land (Kimmorley 2008). Tree species include apple box (Eucalyptus bridgesiana), bundy box (E. goniocalyx), red box (E. polyanthemos), white box (E. albens), yellow box (E. melliodora), tumbledown gum (E. dealbata), red stringybark (E. macrorhyncha) and black cypress pine (Callitris endlicheri) (Goldney 2006; Kerle et al. 2013). Acacia spp. dominate the sparse understorey vegetation and ground cover, which has been severely degraded by sheep along the eastern slope, and consists largely of grass and herbaceous species scattered between rocks, large woody debris and leaf litter (Kerle et al. 2013). Field study Spotlighting surveys were conducted to locate ringtail possums over two nights (11 and 12 March 2014) along the same 7-km fire trail transect that has a north–south alignment along the top of the ridge. Surveys commenced ~30 min after sunset from a vehicle driven at a steady search speed of 5 km h 1 . The tree in which the possum was sighted was identified, its coordinates taken and catalogued and the tree marked with flagging tape. Ringtail possum scats and vegetation samples (leaves, fruits, pods and flowers) were collected from under trees where possums were sighted. Leaves and attached fruit were stored in plastic zip-lock bags and loose gum nuts, pods and scats were stored in individual specimen containers labelled with the site number. In the laboratory, leaves were pressed in a plant press and scats and loose pods stored in 70% ethanol and refrigerated. Journal compilation Ó Australian Mammal Society 2016 www.publish.csiro.au/journals/am CSIRO PUBLISHING Australian Mammalogy, 2016, 38, 130–134 Research Note http://dx.doi.org/10.1071/AM15008