Assessing the control/eradication of an invasive species, the American mink, based on field data; how much would it cost?

Biological invasions are an important cause of biodiversity loss, American mink being one of the worst invasive species in Europe. We performed a 13-week control program of the species in the Butron river system (Northern Spain), where a natural population of the European mink is found. Three population estimates were considered: an absolute minimum, an intermediate scenario and a pessimistic one (n = 35, 49 and 70 animals, respectively). After 2,242 cage trap-nights, trapping success varied from 44 to 89% of these estimates. In addition, we evaluated the costs of eradicating the estimated populations; costs ranged between 652.5 and 2,970 € per mink, and would rise up to 83,462 € for the intermediate estimate under an exponential function linking captures and costs, or ca. 172.500 € to capture the highest estimate under a log-function. The implications of these numbers for the design and implementation of future control projects are discussed.