A feasibility study on the reintroduction of the European Mink (Mustela lutreola) in the Netherlands

In the past three decennia, a dozen mammal species were saved from the brink of extinction through conservation efforts such as reintroductions. The European mink (Mustela lutreola), as the most critically endangered mammal of Europe, requires increased conservation efforts to survive. Since the abolishment of American mink (Neovison vison) farms in the Netherlands, only a very small number of these animals has been observed in the wild, and therefore the question arose whether it would be feasible to reintroduce the European mink in the Netherlands with one of their major threats gone. This project aims to study the possibility of the reintroduction of the European mink in the Netherlands based on the IUCN guidelines for reintroduction, to provide an outline and identify the knowledge gaps that need to be filled for a successful reintroduction in the future.

In general, most threats to the European mink have been mitigated. The presence of the American mink needs to be monitored closely, and its inability to settle in the Netherlands compared to other countries should be researched. The European mink is unlikely to pose a large risk to native Dutch biodiversity such as meadow birds, but is instead likely to consume invasive American crayfish species and aid in its control. There are several societal issues to overcome: the image of the general public of the European mink might be tainted due to COVID-19, and fishermen and trappers are likely to feel inconvenienced. Proper communication and support is necessary to ensure a long-lasting successful project.

The most suitable locations appear to be the Weerribben-Wieden and the Biesbosch, although their prey availability in winter months needs to be studied. A habitat suitability analysis needs to be conducted. The release of animals would have to occur over a span of multiple years, and to reduce the stress of travel in the animals, the best course of action would be to set up a breeding centre in the Netherlands. Each year pregnant females can then be placed in a soft-release enclosure, which can be opened up in August to allow the mothers and their young out in the wild. More research is needed on proper monitoring methods, such as the suitability of radio-harnesses compared to intraperitoneal transmitters and the usage of scats for DNA analysis.