The European beaver (Castor fiber) has been extinct in the Po Valley since the 16th century, but is now making a comeback in northern Italy. Protected by the European Habitats Directive 92/43/EEC, this species has returned after centuries of absence, mainly due to intensive hunting for its fur and glandular secretions, it is estimated that there are now around 50 beavers distributed between Piedmont, South Tyrol and Friuli Venezia Giulia (Italy). This is positive news in a context marked by climate crisis, pollution and land consumption.

Why should we be excited about the return of the beaver? A recent study published in the scientific journal “Biodiversity and Conservation” provides the answer, as it is the first to analyse the ecological effects of the European beaver in a Mediterranean river context.

Beavers are often referred to as 'ecosystem engineers' because their construction activities profoundly alter watercourses. Their dams slow down the flow of water, creating ponds and marshes and making the environment more varied and complex. However, until now, there has been a lack of concrete data on the implications for local wildlife, at least in Italy.

Conducted in Tuscany (Italy) along three rivers (the Ombrone, the Merse and the Tevere), the study compared areas where beavers are present with similar areas without beavers. The researchers used acoustic recorders to monitor the presence of bats and common dormice (Muscardinus avellanarius), two species protected by the European Union's Habitats Directive.

The results were surprising: bat activity was significantly higher in stretches of river inhabited by beavers than in the control areas. The same is true for dormice, which vocalise about ten times more frequently in those areas. In other words, the environment created by beavers is much more hospitable to these species.

The reason? Areas with dams have more insects (which provide food for bats), more shrubs and natural shelters (which are ideal for dormice) and a greater variety of microhabitats. In short, it is a true paradise for river biodiversity.

You can read the full article here: https://link.springer.com/article/10.1007/s10531-025-03044-7