“Species share roosts sites, but segregate spatially within”
Observations from previous studies commonly report co-occupation of roosts by multiple species, with anecdotal observations of inconsistent overlap or separation within and between trees (Table 2). We observed some horizontal spatial segregation of species, with species showing preference for discrete areas in roosts. In the ‘Lismore’ roost, for example, black flying-foxes were commonly distributed toward the eastern part of the roost and grey-headed flying-foxes in the western part of the roost (Appendix S3). Likewise, in the ‘Clunes’ roost, black flying-foxes were commonly observed toward the north-eastern part of the roost and grey-headed flying-foxes in the south-western part of the roost (Appendix S3). Of 659 occupied subplots across the survey period, only 34.1% (225, binomial confidence interval: 0.31-0.38) showed co-occupation by two different species (Figure 6A). Co-occupation of individual trees by two different species was also relatively low – across surveys where two species were present, 4.6%-7.9% of occupied trees were co-occupied by two species, versus 92.1-95.4% that were occupied by only one species (Figure 6B). Only six trees were ever observed to occupy all three species at once.