Good news from the south: Filling the gap between two otter populations in Italy

Following a severe decline in Italy in the second half of the last century, the Eurasian otter (Lutra lutra) has been confined in the southern part of the peninsula with two isolated nuclei. Similar to other European populations, a slow recovery of the two disjointed populations started in the 90s. Filling the range gap was set as a main objective of the national action plan released in 2011. To assess the achievement of this target we ran a systematic survey in 2017 in the gap area, searching for otter signs in two river basins and two lakes in the Tyrrhenian (Campania) and Adriatic (Puglia) portions of the gap area. Otters were detected along most of the hydrographic network surveyed in the Tyrrhenian side, and only in few sites in the Adriatic side. Results confirmed the gap filling between the two sub ranges, and highlighted the need for a habitat survey in the Adriatic water courses. Our results have implications for the long-term survival of the small and endangered otter population in Italy.