The return of the Eurasian otter in north-eastern Italy. New challenges for biological conservation from Friuli Venezia Giulia Region

The Authors outline the present situation of the Eurasian otter Lutra lutra in Friuli Venezia Giulia Region (north-eastern Italy). After about 50 years from its local extinction, the species is surely coming back. The return probably dated back to 2006, but the first proof was a road kill on the Friulian Morainic Hills in 2011. Biomolecular data indicated an Austrian origin of this first specimen. Field researches did not confirm this evidence until 2014, when otter spraints were found near Fusine in Valromana (Tarvisio, Udine), close to the Italian-Austrian border. Further field work confirmed that the whole Italian Danube Catchment from Tarvisio Municipality is inhabited by a breeding nucleus of 4 to 7 otters. Further bridge otter survey indicated that the distribution of the otters in the whole Friuli Venezia Giulia Region was still increasing, both on the Carnic, Julian and Karavanke Alps, up to the border with Veneto Region. The cohabitation with Neovison vison (Western Carnic Alps) and the road mortality (8 road kills from 2011 to 2019) represent possible threats to the establishment of a viable population in north-eastern Italy.