“Oops…a Beaver Again!” Eurasian Beaver Castor fiber Recorded by Citizen-Science in New Areas of Central and Southern Italy

SIMPLE SUMMARY: Eurasian beavers have been released throughout Europe since the 1900s, with most introductions following the international reintroduction guidelines. Conversely, unauthorised releases have occurred in several countries, e.g., in Spain, Belgium, Scotland, and Central Italy (Tuscany and Umbria regions). In March 2023, other unequivocal presence signs were also detected in southern regions (Molise and Campania), confirming the local presence of beavers. Moreover, two more occurrence sites were recorded in Central Italy (Abruzzi). Despite representing a native species, unauthorised releases of beavers raise management problems, emphasizing the importance of tight monitoring to clarify the actual distribution of this large rodent in these areas. ABSTRACT: The Eurasian beaver Castor fiber was once present in the Palearctic, ranging from the western Iberian Peninsula to northwestern China. In the Middle Ages, this rodent underwent a severe decline in population due to habitat loss, hunting for fur and meat, and the demand for castoreum. At the beginning of 1900, the range of the Eurasian beaver was limited to scattered refugia in Eurasia. Since 1920, legal protection, reintroduction events, and natural spread triggered the recovery of the species in most of its original range. In March 2021, the presence of the Eurasian beaver in Central Italy (Tuscany and Umbria regions) was confirmed through camera trapping after the detection of unequivocal signs of presence (i.e., gnawed trunks). Recordings are located about 550 km south of the known range of this species, thus suggesting that the presence of beavers in Tuscany and Umbria might be due to a local unauthorised reintroduction. In this work, we also reported the presence of beavers in the Abruzzi region and in Southern Italy (Molise-Campania regions), over 380 km in a straight line south to the southernmost record of beaver presence in Central Italy.