Our client sought to gain knowledge of the overall long term viability of mammal populations which they could then use to understand mammal population resilience and potential impacts that may occur on their sites.
Astron developed statistical models that simulated future population trajectories and allowed us to identify potentially negative effects. Our approach was to develop population viability models for four key species and determine the effects of various harvest rates on the safe and potential decline of each population. The model used a wide range of parameters, including appropriate reproduction and mortality rates, and allowed for natural variability in these rates through time. In addition, the model allowed realistic scenarios for potential catastrophic events (fires and cyclones) to also be included, along with harvesting. The analysis was based on a population model that was developed using the statistical programming language R.
The results suggested how robust the fauna populations were and the effects of various harvest rates on population viability. The client was able to make comparisons amongst species at various parameter levels. Uncertainty around the parameter estimates was identified and sensitivity analysis to identify the impact of this uncertainty was suggested. The results of the study are used by the client to manage fauna impacts onsite.