Study of the European otter (Lutra lutra) in the watersheds of the Montpellier metropolitan area

This dataset supports a research study on the recolonisation of Mediterranean rivers by the European otter (Lutra lutra), a protected species and a recognized bioindicator of freshwater ecosystem quality. The study aims to better understand the dynamics of otter re-establishment in a highly anthropogenic environment.The dataset compiles non-invasive monitoring data collected along the Lez River and its tributaries (southern France). It integrates multiple complementary survey methods to document species presence and activity.Presence signs: Field surveys of otter spraints collected along riverbanks and waterways.Camera trapping: Video recordings and detections documenting otter activity as well as other sympatric wildlife species.Environmental DNA (eDNA): Molecular detection of otter and other vertebrate species from aquatic samples collected at study sites.Genetic analyses were performed on spraint samples (individual identification, population origin, and diet characterization). However, these genetic results are not included in the present dataset.