Estimating costs and outcomes of invasive American mink (Neovison vison) management in continental areas: a framework for evidence based control and eradication

Introduced predators are a major threat to biodiversity. While in island ecosystems the favoured management option is species eradication, in continental areas most managers tend to control-orientated options, assuming that eradication is an impossible goal. However, many management actions are conducted without precise or quantifiable goals, and their output is difficult to assess due to the lack of experimental approaches and scientific evidence. Here, we analyse the results of a typical small-scale short-term management action consisting of live-trapping and culling invasive American mink. We estimate the American mink population size at the beginning of the study assuming three different scenarios, assess the output of the management action in each scenario and model the results of further trapping efforts. Based on the results we estimate the effort and economic costs required for culling different population percentages per unit area, as well as the costs and feasibility of eradication. Our results provide a basis for planning invasive predator management, setting realistic management goals and estimating funding required, as well as a framework for managers to evaluate on-going management actions. In addition, our results suggest that American mink eradication from some continental areas would be feasible with current techniques at a moderate-low cost. We suggest that invasive predator management in continental areas should move towards eradication when feasible, regarding control as a second option.