Predation on Amphibians May Enhance Eurasian Otter Recovery in Southern Italy

摘要: Mediterranean freshwaters undergo extreme seasonal variation in water flow, which, exacerbated by withdrawal for agriculture or hydroelectric purposes, may affect fish communities and thus prey availability semi-aquatic predators, such as Eurasian otter Lutra lutra. To investigate the role played food on ongoing recovery of an population at southernmost limit its Italian range, we assessed diet analysis 357 spraints collected from 2014 to 2017 eight rivers, both amphibian by, respectively, electrofishing visual encounter surveys. Fish amphibians formed bulk diet, latter resource contributing much spring. Use otters depended only availability, suggesting that constituted alternative be exploited conditions shortage. Accordingly, showed biomass barely sufficient sustain current population. ATR-FT-IR spectroscopy allowed point out first time occurrence eggs spraints, although co-occurrence anuran bones did not allow discriminate between direct passive predation. Overall results indicate expansion even survival this small depend effective management resources reinforcement assemblages.