Eurasian mink (Mustela lutreola) is a semi-aquatic mammal known for its dark, glossy fur and distinctive white markings on the chin and throat. It inhabits dense riverbank vegetation and feeds on aquatic prey. It is critically endangered due to habitat loss and competition with the invasive American mink (Neovison vison), which is larger and more adaptable.

The European mink (Mustela lutreola) and the American mink (Neovison vison) have distinct native regions. The European mink is native to Europe, primarily found in Eastern Europe, including countries like Russia, Romania, and Ukraine. Historically, it was present throughout much of Europe but has experienced significant range reductions. The American mink is native to North America, found across Canada, the United States, and parts of Mexico. It has also been introduced to other regions, including Europe and South America, where it is considered invasive.

European mink typically inhabit densely vegetated areas near freshwater bodies such as rivers, streams, and lakes. They prefer climates that maintain the presence of water bodies year-round. The American mink is adaptable to a wide range of habitats but also prefers wetland areas like marshes, riverbanks, and coastal regions. Both species thrive in temperate climates and rely on access to fresh water to support their semi-aquatic lifestyles.

Both the European and American mink are carnivorous and play roles as predators in their ecosystems. They primarily feed on small mammals, birds, fish, and amphibians. Their semi-aquatic nature allows them to exploit resources from both terrestrial and aquatic environments. The European mink's niche has been threatened by habitat loss and competition with the introduced American mink, which is more adaptable and has led to declines in native populations.