European mink

The European mink, known scientifically as *Mustela lutreola*, is a semiaquatic mustelid native to Europe.

This small mammal is a vital part of river and stream ecosystems. It is a specialized hunter that lives primarily near forest streams that are unlikely to freeze during the winter. Although it looks very similar to the American mink, the two species are not closely related. Instead, the European mink is much closer to the European polecat and the Siberian weasel. This distinction is important for scientists studying how different species evolve and interact in the same environments.

Physically, the European mink has a long, slender body and very short limbs.

This shape is typical for the genus *Mustela*. Its head is large and broad with short ears. One of its most important tools for survival is its specialized fur. The winter coat is thick, dense, and silky to provide insulation in cold water. The underfur is especially dense, while the outer guard hairs are coarse and lustrous. These guard hairs are flat in the middle, which is a common adaptation in aquatic mammals to help them stay warm. A key way to identify this species is by the pure white markings on its upper and lower lips.

This is different from the American mink, which rarely has white marks on the upper lip.

The European mink is a highly skilled swimmer and diver. It can stay underwater for one to two minutes at a time. When swimming, it uses a coordinated movement, paddling with both its front and back limbs simultaneously.

This agility allows it to hunt a wide variety of prey. Its diet consists of aquatic and riparian fauna, such as voles, frogs, fish, crustaceans, and insects. Voles are its most important food source. In areas with plenty of water, it can even catch fish weighing up to 150 grams. To ensure survival, the mink often caches, or stores, its food when it is abundant.

These animals lead complex lives with specific home ranges and shelters.

A mink's territory size depends on how much food is available in the area. In places with little food, a home range might be only 1.5 kilometers long. In more fertile areas, territories are usually larger. The mink uses both permanent burrows and temporary shelters. A permanent burrow is usually located no more than 10 meters from the water's edge. These burrows consist of one or two passages that lead to a nest chamber. The mink lines these chambers with materials like straw, moss, mouse wool, and bird feathers.

Reproduction for the European mink follows a specific seasonal cycle. During the mating season, a female's sexual organs enlarge and turn a pinkish-lilac color.

An average litter consists of three to seven kits. When kits are born, they are blind and weigh approximately 25 grams. They grow at an incredible rate, often tripling their weight just ten days after birth. The kits stay with their mother for about two to two and a half months. After about 70 to 84 days, the young minks become independent and begin hunting on their own.

The history of the European mink is marked by a significant and rapid decline.

In the 19th century, the species began to shrink, and it became extinct in parts of Central Europe. Over the last 150 years, the population has decreased by more than 90%. Scientists have identified several causes for this decline. These include habitat destruction and changes in the climate. In some regions, such as Estonia, the decline coincided with the arrival of the American mink. The American mink competes for food and can spread diseases to the European species. In other areas, like Central Europe, the decline started even before the American mink arrived, likely due to the destruction of river ecosystems.

Today, the situation for the European mink is very serious. The IUCN lists the species as Critically Endangered because its numbers are dropping so quickly. It is expected to decline by more than 80% over the next three generations.

Currently, the remaining populations are mostly in Eastern Europe, with small, isolated groups in France and Spain. However, there is hope through conservation efforts. In Estonia, work is being done to re-establish the mink on different islands. In 2022, the first minks arrived on the island of Saaremaa as part of a project to bring the species back to its natural habitat.