Extinction in Eden: identifying the role of climate change in the decline of the koala in south-eastern NSW
Daniel Lunney A,B,F, Eleanor Stalenberg A,C, Truly Santika D,E and Jonathan R. Rhodes D,E
A Office of Environment and Heritage NSW, PO Box 1967, Hurstville, NSW 2220, Australia.
B Veterinary and Life Sciences, Murdoch University, Perth, WA 6150, Australia.
C Australian National University, Division of Evolution, Ecology and Genetics, Research School of Biology,
Canberra, ACT 0200, Australia.
D The University of Queensland, School of Geography, Planning and Environmental Management, Brisbane, Qld 4072, Australia.
E NERP Environmental Decisions Hub, The University of Queensland, Brisbane, Qld 4072, Australia.
F Corresponding author. Email:
Context Reviews of climate change in Australia have identified that it is imposing additional stresses on biodiversity, which is already under threat from multiple human impacts.
Aims The present study aimed to determine the contributions of several factors to the demise of the koala in the Eden region in south-eastern New South Wales and, in particular, to establish to what extent climate change may have exacerbated the decline.
Methods The study built on several community-based koala surveys in the Eden region since 1986, verified through interviews with survey respondents. Historical records as far back as the late 19th century, wildlife databases and field based surveys were used to independently validate the community survey data and form a reliable picture of changes in the Eden koala population. Analysis of the community survey data used a logistic model to assess the contribution of known threats to koalas, including habitat loss measured as changes in foliage projective cover, fire, increases in the human population and climate change in the form of changes in temperature and rainfall, to the regional decline of this species.
Key results We found a marked, long-term shrinkage in the distribution of the koala across the Eden region. Our modelling demonstrated that a succession of multiple threats to koalas from land use (human population growth and habitat loss) and environmental change (temperature increase and drought) were significant contributors to this decline.
Conclusions Climate change, particularly drought and rising temperatures, has been a hitherto hidden factor that has been a major driver of the decline of the koala in the Eden region.
Implications Development of strategies to help fauna adapt to the changing climate is of paramount importance, particularly at a local scale.