The European mink (Mustela lutreola) is a semi-aquatic mustelid that is defined by sporting a distinctive uniform chocolate brown color throughout the body, except for two small white spots, one on the upper lip and the other on the lower lip.

The appearance of the European mink is very similar between males and females, with the larger size of the male specimens being the most visible difference. These mammals are excellent swimmers thanks to their membranes on their hands and feet that make it easier for them to handle themselves with ease in the aquatic environment, although it is the terrestrial environment where they perform best. Their elongated figure and the small size of their ears and tail allow them to move through the dense vegetation without hardly being discovered.

The species is distributed for the most part within the Natura 2000 Network, in five Autonomous Communities located in the north and northeast of Spain where it occupies more than 1,500 kilometers of rivers. They are solitary and territorial mammals. They are capable of living in well-differentiated areas such as the Cantabrian basins or the Mediterranean slope of the Ebro valley. The optimal habitat of the European mink includes wide banks and dense vegetation cover, showing a preference for the lower and middle course of rivers.

European minks are carnivores and forage for their food during the night and twilight. Their diet is made up of the most abundant and available prey at any given time, such as rats, water rats, mice and voles, amphibians, fish and crabs, as long as they all live in bodies of water and their shores.

The presence of the European mink is mainly conditioned by trophic resources and the presence of refuges, as they influence the quality of the water and the alteration of the banks. Because of this, they tend to avoid heavily polluted rivers with modified banks.

In Spain, the International Union for Conservation of Nature (IUCN) estimates that the population size of this species does not exceed 500 individuals. In Europe, its population has decreased by more than 90% since the beginning of the twentieth century, which is why, today, and due to this alarming regressive trend, it is considered the most endangered mammal in Europe.

The main threat to the European mink is the presence of the American mink as an invasive species, which causes its rapid disappearance through direct aggression and competition for space. Other threats that can reduce the number of European minks are the destruction and degradation of their habitat, death by being run over due to the roads that cross the areas where they live, drowning inside irrigation siphons that they use as feeding places, canine distemper virus and Aleutian mink disease. diseases that affect other carnivores, wild and domestic, and the genetic similarity between local minks that makes them closely related and means that they have fewer possibilities of adaptation to environmental changes, fewer defenses against diseases and therefore, a greater risk of extinction. In addition, the lack of knowledge about its status because it is a very discreet species can limit the possibilities of working on different actions for its conservation.

The IUCN Red List of Threatened Species lists the European mink as “critically endangered” and the 2011 List of Wild Species under Special Protection and the National Catalogue of Threatened Species classifies these mammals as “endangered”.

For all these reasons, the Biodiversity Foundation of the Ministry of Agriculture, Food and the Environment, in its clear commitment to the conservation of the species, collaborates with the European Mink Association, within the framework of the LIFE Lutreola Spain project that aims to eradicate the nuclei of the American mink as an invasive species, established within the distribution area of the native species and improve the knowledge of the species to prevent its disappearance in the wild. In addition, the Biodiversity Foundation also collaborates through Calls for Grants with the Terra Naturalis Association in these same tasks in the autonomous communities of Castilla La Mancha and Aragón and supports the Foundation for Research in Ethology and Biodiversity (FIEB) in the ex situ conservation program of the European mink.