“Individual roosts have distinguishable seasonal patterns of
abundance and occupation.” & “Intra- and inter-annual variations in
abundance can be extreme” &“Roost abundance peaks in March”
Prior studies reported inconsistent patterns in occupancy and abundance
(Table 2). In out dataset, seasonal patterns in abundance and density
were roost specific (Figure 9). Some roosts showed patterns consistent
with the general notion that total roost abundance peaks towards March
(Nelson 1965b; State of NSW and Office of Environment and Heritage 2018)
(e.g. ‘Redcliffe’, ‘Canungra’ and ‘Clunes’). Others showed no
considerable fluctuation in abundance (‘Burleigh’) or peaks at other
times (‘Toowoomba’, ‘Sunnybank’, ‘Avondale’, ‘Lismore’) (Figure 9). The
latter cases potentially highlight that population dynamics are more
strongly driven by local dynamics in these roosts (e.g. food
availability) (Parry-Jones & Augee 1992; Eby et al. 1999;
Parry‐Jones & Augee 2001; Giles et al. 2016), than reproductive
cycles as described in Nelson (1965b). Little red flying-foxes showed
seasonal trends in occupancy and density, peaking in February-March
(Appendix S2). Seasonal trends in grey-headed and black flying-fox
numbers were less consistent between roost sites (Appendix S2).
Discussion
The success of efforts to conserve Pteropodid bats across their
distribution relies on effective population and habitat management.
Pivotal to this is a baseline understanding of species ecology and
behaviour, which is currently lacking for the majority of these species
(Fujita & Tuttle 1991; Mickleburgh, Hutson & Racey 2002). Here we
provide a synthesis on all existing literature, as well as an
unprecedented empirical dataset, to meet that need for Australian
species of Pteropus . We highlight that many existing beliefs on
which conservation and management decisions are based, are unsupported
or outdated, and suggest that management plans should be updated to
incorporate improved knowledge. Most importantly, we highlight that a
one-size-fits-all approach to roost management will be inappropriate,
given the extent of variation between sites even within a regional area.
Roost management guidelines need to be changed to promote a more
tailored approach that requires preliminary data acquisition before
management plans are formulated and approved.