Genetic and viability assessment of a reintroduced Eurasian otter <i>Lutra lutra</i> population on the River Ticino, Italy

Abstract On the River Ticino in northern Italy, a small number of captive Eurasian otters Lutra lutra , belonging to European breeding programme for self-sustaining populations, were reintroduced 1997, after species had been declared locally extinct 1980s. We surveyed otter signs 2008, 2010, 2016–2017 and 2018, confirming presence what is probably population. To assess abundance viability population, we genotyped fresh spraints collected during last two surveys, using 11 microsatellite markers, modelled population trend Vortex . A minimum six individuals identified from 25 faecal samples. The analysis mitochondrial DNA determined that share transversion characteristic Asiatic subspecies barang contribution genetic pool captive-bred founder Population size was consistent with release three pairs all models implied founders too ensure long-term survival Stochastic factors are therefore likely threaten success this reintroduction.