Study species

Sugar gliders are small (90-150g) gliding possums native to the Australian mainland but were introduced to Tasmania (Campbell et al. , 2018). They are omnivores and eat nectar, tree sap and insects but they also opportunistically eat vertebrate prey (Fleay, 1947, Smith, 1982, Stojanovic et al. , 2014). They are hollow-dependent, often den in family groups and interchangeably use multiple tree hollows for denning (Suckling, 1984). Previous estimates of population densities in continuous forest range from 0.09-0.54 ha- (Gracaninet al. , 2022, Jackson, 2000b, Quin, 1995).
Studies of sugar gliders vary in the methods used and the success achieved. Monitoring methods for sugar gliders on mainland Australia have traditionally included live-trapping, nest box surveys and spotlighting (Jackson, 2000b, Quin, 1995, Smith & Phillips, 1984, Suckling, 1984, Traill & Lill, 1998). Call playback with conspecific or owl calls is another method to detect gliders (Alexander, Scotts & Loyn, 2002, Davey, 1990) and estimate occupancy (Allen et al. , 2018). Although these methods can indicate sugar glider occupancy or abundance, they have limitations, especially when population densities are low. Gracanin et al. (2019) recently introduced the novel ‘selfie-trap’ to identify individual sugar gliders at close-range. Sugar gliders have unique head stripes, scent glands, tail tip colours, and often unique ear scars, making unmarked individuals identifiable in photos. Compared to live-trapping, ‘selfie-traps’ provide a higher detection probability and more accurate density estimate (Gracaninet al. , 2022).
Sugar gliders are usually surveyed with a standard mammal bait comprised of peanut butter, honey and oats, in combination with a honey-water lure sprayed around the trap (Caryl, Thomson & van der Ree, 2013, Knipler, Dowton & Mikac, 2022, Nowack et al. , 2015, Winning & King, 2007). In Tasmania, this approach has been ineffective even where sugar gliders are known to be present (Stojanovic et al., 2019). The published literature contains numerous comparisons of the efficacy of different survey methods (Davey, 1990, Goldingay & Taylor, 2021, Gracaninet al. , 2022, Vinson, Johnson & Mikac, 2020) and trapping techniques (Mawbey, 1989, Smith & Phillips, 1984, Winning & King, 2007) for Australian arboreal mammals including various glider species. However, none have investigated the impact of bait type (herbivore or predator based) on sugar glider detectability. This is a major gap in the literature given recent recognition of their widespread predation on vertebrates (Crates et al. , 2019, Stojanovic et al. , 2018, Stojanovic et al. , 2014).