European river otter, Netherlands

The European river otter, pictured here, is more than just an adorable face in the wild. Found across Europe, Asia, and parts of northern Africa, these otters thrive in clean rivers, lakes, and wetlands, serving as an important indicator of environmental health. These semi-aquatic animals are built for agility, with streamlined bodies, webbed feet, and dense fur that keeps them warm even in icy waters. A single square inch of their fur can hold more than 400,000 hairs, making it one of nature's most effective insulators. River otters were once endangered due to pollution and habitat loss. Yet, thanks to conservation efforts, their populations are rebounding in many regions across Europe.
Otters are naturally playful, often sliding down snowy or muddy banks and diving underwater to find pebbles to play with. These solitary creatures communicate using a repertoire of whistles, squeaks, and even scent, which also helps them mark their territorial boundaries. If you find yourself near a serene river in their range, keep an eye out—you might just spot one of these elusive river-dwellers.
© Ernst Dirksen/Minden Pictures