On the River Ticino (Piedmont and Lombardy regions, N Italy), the Eurasian otter Lutra lutra became extinct in the 1980s and was reintroduced in 1997. Since then, the status of the reintroduced population has been assessed only occasionally, in 2008 and 2010. Between 2016 and 2018, we conducted an extensive survey for otter signs along the whole Italian stretch of the River Ticino, following the ‘Standard Method’ for otter surveys. In 2016–2017, we found 101 spraints (mean marking intensity: 0.40 spraints/100 m), spread over a 97-km long stretch of the river. In 2018 only five spraints were collected, the two furthermost marking sites being 32 km apart. Genotyping of nDNA extracted from 21 faecal samples enabled the identification of six different individuals. The surveys led to drawing a reliable picture of otter distribution and population size, with evidence of otter occurrence on a longer than previously recorded stretch of the river. The results of the 2018 survey suggest that stochastic factors may still threaten the survival of reintroduced otters and would suggest a reinforcement of the population is required to increase its genetic diversity.
Otters were once widespread in the Austrian Alps, but their distribution and decline were not documented properly. By the 1980s, otters were virtually extinct. It remains unclear if some of the otter signs recorded within the 1980s in the Alps originated from a relict population or were migrants from source populations in the north and east of Austria, both outside the Alps.
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.
In the 20th century, the Eurasian otter (Lutra lutra) became extinct in large areas of central Europe. Several factors contributed to this dramatic decline, as for instance hunting, accidental mortality, pollution and habitat destruction. Even if some public opinion states that following this decline wild animals should not be held in captivity, it has been advisable to hold otters in captivity for possible reintroduction projects.
A first step toward a common view and a shared strategy for the conservatin of the Eurasian otter (Lutra lutra) was discussed in the international meeting organized by the Gran Paradiso National Park at Valsavaranche on 10–12 October, 2018, that was attended by public administrations, IUCN and NGOs representatives from Austria, France, Germany, Italy, Slovenia and Switzerland. The meeting ended on a shared road map towards a common conservation strategy for the otter and for joined efforts to get a financial support for its implementation. Moreover, participants of the meeting agreed on a ‘IUCN Otter in the Alps Manifesto’, which is reported in the Appendix.
