The impact of fire and dogs on Koalas at Port Stephens, New South Wales, using population viability analysis
Daniel Lunney1,*, Shaan Gresser1, Lisa E. O'Neill1,2, Alison Matthews1,2 and Jonathan Rhodes3
1Department of Environment and Conservation (NSW), PO Box 1967, Hurstville, New South Wales, Australia, 2200
2School of Environmental and Information Sciences, Charles Stuart University, Albury, New South Wales, Australia, 2640
3School of Geography, Planning and Architecture, University of Queensland, Brisbane, Queensland, Australia 4072. Current address, CSIRO Marine and Atmospheric Research, GPO Box 1538 Hobart, Tasmania, Australia, 7001
The Port Stephens Koala Phascolarctos cinereus population has been regarded as one of the strongholds for koalas in New South Wales. This study applied population viability analysis to investigate the impact of fire and predation by dogs on the viability of the local population. The rapid decline of the modelled koala population under basic assumptions throws the assumed security of such large populations into question. In all the modelled management scenarios, reducing mortality had more influence than any other factor. Reducing the severity and frequency of large catastrophic fires improved the probability of survival for the population, though the modelled population size still declined sharply. Any management action to improve koala survival must be accompanied by a reduction in mortality from dog attacks. Fires and dogs will have an even greater impact on koala populations as coastal forests become more fragmented and isolated by urban development, and their combined control will be needed to complement land-use planning measures to address habitat loss and fragmentation.