Alison Matthews

Modelling mammalian extinction and forecasting recovery: koalas at Iluka (NSW, Australia)

This study investigated the recent demise of a koala population at Iluka in eastern Australia and demonstrates the potential role of population viability analysis (PVA) in the recovery and management of similar small populations. Information about the Iluka population was reconstructed from various sources, including community knowledge, wildlife carer data, and from a radiotracking program. Modelling scenarios were constructed to identify which factors may be critical to the survival of the Iluka population and which management options could provide the most effective means of its recovery. The model suggested that even substantial improvements in mortality and fertility alone do not prevent the modelled population declining towards extinction. Rebuilding of the koala population is likely to require guaranteed regular immigration of animals of both sexes in conjunction with considerable improvements in population mortality and fertility. This highlights the importance of the metapopulation for recruitment, an outcome that was not expected prior to modelling. These modelling outcomes suggest that the management of small, local populations of koalas will need a concerted management effort focusing on multiple causes of population change. Local management actions, such as reducing road deaths and managing habitat and fire, must be accompanied by knowledge of the larger geographical population.

An Economic Evaluation of Local Government Approaches to Koala Conservation

Local decision-making is crucial to the process of retaining the habitat of threatened species on private lands. However, there has been little attention given to the issue of local government and biodiversity conservation. The objective of this study was to assist Coffs Harbour City Council interpret a draft Plan of Management for koalas within its borders. The study was designed to answer two questions: 1) What will be the economic impact on residents of the requirement to abide by New South Wales state environmental planning policy to conserve koalas (SEPP 44), by way of individual development approvals; and 2) What will be the economic impact on residents of implementing SEPP 44 by way of a shire-wide Plan of Management. A comparison of the costs and benefits of a shire-wide plan shows that the benefits were more than double those of the costs of piecemeal decision-making, i.e. a decision after a development application has been lodged. Thus, a strategic approach is cost-efficient. The success of this work should provide an impetus for other councils currently considering whether to adopt a shire-wide program for conserving remnant koala habitat on private lands within their jurisdiction.