A multi-dimensional assessment of the 2021 mouse plague in New South Wales, Australia: Economic impacts and policy responses

Despite the periodic mouse plague outbreaks in Australia which largely occur due to favourable climatic conditions, their economic impacts remain understudied. To bridge this knowledge gap, the present study analysed the economic impacts of the 2021 mouse plague in New South Wales (Australia) among households, farms, and businesses/facilities. We further analysed the influence of selected cost parameters on mouse bait rebate claims by the farmers as well as the relative efficiency of the chemical mouse control options used by farmers to minimize avoidable crop yield losses. Our study found that the total direct cost of the 2021 mouse plague was A$ 100.62 million, with farmers bearing 67.10% of the total cost. It was also revealed that the type of farming influenced the likelihood of a farmer claiming or not claiming mouse bait rebate. The most efficient chemical mouse control option was the combination of anticoagulants used around buildings and zinc phosphide used in pastures and crops as it reduced avoidable crop yield losses more than each rodenticide when used independently. However, more research is required on how other variables may influence the efficiency of mouse control methods to forestall future outbreaks of mouse plagues and their associated economic impacts.