Establishing foundations: Designing a long-term experiment to evaluate whether nestboxes assist population recovery of an endangered species after fire

The loss of hollow-bearing trees drives population declines of
hollow-dependent species. Disturbances such as wildfire can exacerbate
these declines. Artificial structures, like nestboxes, are a commonly used
management tool that attempts to offset hollow loss. However, the
effectiveness of nestboxes as a conservation strategy is rarely tested
within an experimental framework. The endangered southern greater glider
(Petauroides volans) is an obligate hollow-dependent arboreal marsupial
that is highly sensitive to wildfire. Southern greater glider populations
experienced high mortality and habitat loss following the 2019/2020
megafires in south-eastern Australia. To test whether purpose-built
nestboxes could assist the post-fire population recovery of the southern
greater glider, we established a long-term, landscape-scale experiment. We
installed a total of 234 nestboxes at sites in East Gippsland
(north-eastern Victoria) and Tallaganda (southern New South Wales).
Nestbox sites were matched to control sites. We undertook spotlighting
surveys in both study areas and installed camera traps at a subset of
nestboxes. We observed southern greater gliders using nestboxes in both
regions, with substantially more observations in Tallaganda. However, we
did not find a significant difference in southern greater glider abundance
between nestbox and control sites. In Tallaganda, we found more southern
greater gliders in areas of lower fire severity. The longer-term outcomes
of our study will inform the use of nestboxes as a tool to assist in the
recovery of southern greater gliders following disturbance.