Nestbox use and predicted distribution of the southern greater glider (Petauroides volans) following the Black Summer megafires.

Abstract

Species losses and declines continue to occur across the globe and are predicted to increase exponentially due to anthropogenic climate change. South-eastern Australia has been identified as a future extinction hotspot for terrestrial mammal fauna. The southern greater glider (Petauroides volans), Australia's (and the world's) largest gliding marsupial, was recently uplisted from Vulnerable to Endangered under the Environment Protection and Biodiversity Conservation Act 1999. Southern greater gliders are fire-sensitive and severely threatened by the loss of hollow-bearing trees associated with logging and altered fire regimes. In 2019/2020, after an extended period of drought, south-eastern Australia experienced wildfires over an eight-month period. These wildfires, referred to here as the 2019/2020 megafires, were unprecedented in severity and extent, and affected large parts of southern greater glider habitat in Victoria and New South Wales. Careful post-fire management is essential for species persistence. Landowners, conservationists, and researchers have implemented various conservation actions to protect species following fire. With a projected increase in the severity, intensity, and frequency of wildfires, understanding where southern greater gliders can persist across the landscape is essential for their management. In Chapter 1, I aimed to determine where southern greater gliders were predicted to occur in the two years before and two years following the 2019/2020 megafires. Using a Maximum entropy (Maxent) species distribution model, I found that the predicted southern greater glider distribution remained stable throughout this period; however, there was a clear decline in marginal (moderately suitable) southern greater glider habitat. Forests at higher elevations (>750m) and that experienced lower fire severity and fewer fires demonstrated higher likelihoods of species occurrence. Nestboxes are a common tool used to supplement hollow loss, yet successful implementation is often limited and difficult to quantify. In Chapter 2, I implemented a landscape-scale nestbox study in areas affected by the 2019/2020 megafires, with the aim of testing effectiveness of nestboxes as a post-fire recovery tool for the southern greater glider. Nestboxes were purpose built and installed at sites within Tallaganda National Park and State Conservation area, New South Wales and within the forests of the East Gippsland region, Victoria. I conducted spotlighting surveys at nestbox sites and control sites (without nestboxes) before and after nestbox installation. Southern greater gliders occupied nestboxes in both study areas. They were the dominant species identified occupying nest boxes and during spotlighting surveys in Tallaganda, however, were not the dominant species in East Gippsland. I also found there were fewer southern greater gliders in areas of higher fire severity within Tallaganda. My work outlines the establishment of a long-term study that hopes to quantify the utility of nestboxes in supporting the post-fire recovery of this Endangered species. Southern greater gliders continue to persist in forests affected by the 2019/2020 megafires. However, my research has revealed that increased fire severity and frequency decreases habitat suitability for this species. Nestboxes may provide an adequate recovery tool to assist population recovery, however, more research is required to understand the complex interactions that may limit post-fire recovery of southern greater gliders. Show more