A Eurasian otter Lutra lutra (Linnaeus 1758) (Carnivora: Mustelidae) in the Tiber basin near Rome: relict or range expansion?

The Eurasian otter Lutra lutra faced a significant decline in Italy during the 20th century, leading to local extinctions. After fifty years of otter disappearance from the Tiber basin, this study documents a sighting near Rome, obtained during a long-term trail camera monitoring. The study area, Rio Moscio, offers a habitat rich in hygrophilous vegetation and diverse fauna, including other protected species such as the Italian wolf, the European wildcat, and the European polecat. The observed otter could either mark a potential range expansion or could challenge the presumed extinctions in this region, since it could be in dispersal from the closer known populations or an individual from a Tiber basin relict population. The study emphasises the need for continued monitoring and prompt future genetic analyses to obtain necessary insights for conserving otters in Central Italy.