Oral presentation- Open Session 12th International Mammalogical Congress

Decline of small mammals in south east Australia: role of refuges and implications for management (#478)

Barbara Wilson 1 , Mark Garkaklis 1 2 , Lily Zhuang-Griffin 1
  1. School of Life & Environmental Science, Deakin University, Geelong, Victoria, Australia
  2. School Agriculture & Resource economics, University of Western Australia, Perth, Western Australia, Australia

Longitudinal studies quantifying population changes are required to activate effective management and monitoring regimes.  The population dynamics of small mammals in the eastern Otway region of south-east Australia were assessed across the landscape between 1975 and 2007.  The aims of this paper were to evaluate the current (2013-17) population abundance of species in the region compared to historical records, to consider current threats and identify management actions.  The current status of species was assessed at 40 sites, utilising live-trapping and camera trapping techniques. Trap success rate was compared to long-term data using time-series analyses to identify periods of decline for target species Antechinus minimus, Rattus lutreolus and R. fuscipes. Sites trapped in 2013-2017 predominantly had few or no native species present, compared to previous records of four to seven species. Most species exhibited significant declines (>95%), including two threatened species (Antechinus minimus, Pseudomys novaehollandiae).  While significant declines were recorded in woodland, forest and estuarine habitats, higher mammal capture rates (20 - 47%) and native species richness (9) were recorded at coastal dune sites, indicating that these habitats provide important refuges for mammals. Control charts identified significant declines retrospectively, and if used routinely would have alerted authorities in a timely fashion enabling management that may have prevented extirpation at some sites. Management actions required include: prevention of further habitat fragmentation; implementation of burning regimes to protect key refuge habitat; and predator control. Effective monitoring is essential to allow an evaluation of the success of management actions.