Diet of an inland population of the common ringtail possum (Pseudocheirus peregrinus)

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.

Oils ain’t oils: can truffle-infused food additives improve detection of rare and cryptic mycophagous mammals?

We tested whether an artificial food additive, truffle oil, improved detection of mycophagous mammals when added to a standard bait type of peanut butter and rolled oats used with camera traps. Sixteen mammalian taxa were subsequently recorded, the most common being antechinus, bush rat (Rattus fuscipes), swamp wallaby (Wallabia bicolor) and long-nosed bandicoot (Perameles nasuta) as well as the long-nosed potoroo (Potorous tridactylus) and southern brown bandicoot (Isoodon obesulus). The only species for which detection rate was improved by the addition of truffle oil to standard bait was the ringtail possum (Pseudocheirus peregrinus), a species that has never been recorded eating fungi. In contrast, the total number of detections of all species at any given site was significantly higher, on average, using standard bait without truffle oil, as was the average number of detections of the partially mycophagous bush rat. Time to first detection of bush rats and swamp wallabies was significantly shorter using the standard bait type, compared with one with truffle oil added. Overall, the use of the truffle oil additive did not improve the chance or rate of detecting mycophagous mammals. To maximise the number of detections of mammals at camera traps the use of a standard bait type of peanut butter and rolled oats is recommended.

Geographic variation in the diet of the powerful owl (Ninox strenua) at a local scale

This study reports the diet of the powerful owl (Ninox strenua) in East Gippsland, from a dataset of 2009 vertebrate prey items collected from 53 sites. Mammals dominated the diet at all sites, but birds were also consumed regularly. The greater glider (Petauroides volans) was the dominant dietary item across the region in terms of both frequency of consumption and biomass contribution. There was geographical dietary variation between coastal and foothill forest sites, with the sugar glider (Petaurus breviceps) and birds consumed more frequently in foothill forests, whereas the common ringtail possum (Pseudocheirus peregrinus) was frequently consumed only in coastal forests. Typically, a higher percentage of powerful owl diet comprised birds closer to cleared land. The dietary reliance upon hollow-dependent mammals in foothill forests (averaging >70%) is of conservation concern, especially when non-hollow-dependent prey are rare. Forest management activities, especially logging, that reduce densities of hollow-bearing trees in the landscape are therefore likely to decrease the long-term carrying capacity of the landscape for the powerful owl.

Will arboreal mammals use rope-bridges across a highway in eastern Australia?

Artificial structures designed to promote road-crossing by arboreal mammals are increasingly being installed in Australia but there is a limited understanding of their usefulness. We studied five 50–70-m-long rope-bridges (encompassing three designs) erected across the Pacific Highway, a major freeway in eastern Australia. Native arboreal mammals showed a willingness to explore these structures, being detected by camera traps on four rope-bridges. The vulnerable squirrel glider (Petaurus norfolcensis) crossed on one rope-bridge at least once every 4.5 weeks over a 32-week period. The feathertail glider (Acrobates pygmaeus), common ringtail possum (Pseudocheirus peregrinus) and the common brushtail possum (Trichosurus vulpecula) were detected on one of two rope-bridges that extended under the freeway at creek crossings. The feathertail glider was detected on all three rope-bridge designs. Our results suggest that rope-bridges have the potential to restore habitat connectivity disrupted by roads for some arboreal mammals. Further research is needed to refine the design and placement of rope-bridges as well as to determine whether these structures promote gene flow.

An inland population of the common ringtail possum (Pseudocheirus peregrinus) at Black Rock Ridge, New South Wales: a preliminary ecological assessment

The common ringtail possum (Pseudocheirus peregrinus) is considered abundant throughout its distribution in eastern Australia but appears to be declining at a regional level in inland New South Wales. Previous studies of the common ringtail possum in south-eastern Australia have focussed on coastal populations and little is known about the ecology of inland populations. In south-western Australia studies of the closely related western ringtail possum (Pseudocherius occidentalis) have found that coastal populations differ from inland populations, particularly in their nesting behaviour. In this preliminary study of an inland population of the common ringtail possum at Black Rock Ridge in central west New South Wales population density has been estimated and the habitat and nesting preference assessed. Up to one ringtail per hectare and 4.5 ringtails per spotlight hour were recorded. Tree hollows appeared to be the preferred nest site, with possums seen entering hollows during spotlighting and no dreys being located. Threats to common ringtail possums at Black Rock Ridge include the isolation of the remnant ridge vegetation within an extensively cleared landscape and the associated change in fire regimes. Within this landscape there has been an extensive reduction in available habitat, and an overall lack of habitat connectivity has placed ringtail possums at an increased risk of predation.