Reintroduction and “rewilding” activities are some of the main tools used in the field of conservation biology to mitigate the impacts of humans on the environment and restore ecosystems to a more natural state. As reported by AGI, these actions can sometimes pose some challenges, especially when the species involved are large carnivores, large herbivores, or “ecosystem engineers,” species that can significantly modify habitats and landscapes with their activities. Until a few years ago, the European beaver (Castor fiber) was completely absent from Italy, as hunting and habitat loss had led to the extinction of all populations in the country.
After more than 500 years of total absence, this species has recently begun recolonizing Italy due to natural expansion from Austria towards Trentino Alto-Adige and Friuli Venezia-Giulia, and unauthorized reintroductions in central Italy (Tuscany, Umbria, Marche). In a study published in Animal Conservation, researchers from the University of Milan and the Institute of Terrestrial Ecosystem Research of the National Research Council (CNR-Iret) in Sesto Fiorentino (Florence) collected all available presence data for the beaver in Europe, using species distribution databases (iNaturalist, GBIF) and targeted field research funded by the Beaver Trust (UK). The activities were coordinated by CNR-Iret, the Italian beneficiary of the Beaver Trust fund for beaver research in Italy.
“We have overseen monitoring activities, collected samples for genetic analysis, monitored presence points, conducted possible necropsies, and determined the effects on forest ecosystems,” says Emiliano Mori (CNR-Iret), the principal investigator of the project, along with Andrea Viviano (CNR-Iret). Species distribution models were then used to estimate the environmental suitability for beavers in Europe. Subsequently, using connectivity models, experts evaluated which areas in Italy were most likely to see beaver expansion in the near future.
The resulting connectivity model map was overlaid with maps of tree cultivation and the presence of artificial canals to identify areas where beaver construction activities, such as burrows and dams, could potentially conflict with human activities. “Wide areas of Italy appear to be suitable for beaver stabilization, and while northern populations seem more isolated, in central Italy, we have identified a greater potential for species expansion.”