https://ipt.gbif.fr/resource?r=otter_gimenez Olivier Gimenez CEFE https://orcid.org/0000-0001-7001-5142 Simon Lacombe CEFE https://orcid.org/0009-0005-8767-989X Montpellier Méditerranée Métropole distributor Ville de Montpellier distributor 2026-02-17 eng 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. Occurrence European otter Lutra lutra Non-invasive monitoring Camera trapping Environmental DNA Spraint surveys Freshwater ecosystems River monitoring Urban ecology Wildlife recolonisation Protected species Ecological connectivity Green and Blue Infrastructure Long-term ecological monitoring Mediterranean rivers GBIF Dataset Type Vocabulary: http://rs.gbif.org/vocabulary/gbif/dataset_type_2015-07-10.xml Observation GBIF Dataset Subtype Vocabulary: http://rs.gbif.org/vocabulary/gbif/dataset_subtype.xml This work is licensed under a Creative Commons Attribution (CC-BY 4.0) License. Creative Commons Attribution 4.0 International https://spdx.org/licenses/CC-BY-4.0.html CC-BY-4.0 N/A 3.729006 4.180832 43.924264 43.534207 2020-01-01 2025-06-02 family Sylviidae family Mugilidae family Argentinidae family Sphyraenidae family Phylloscopidae order Anseriformes family Columbidae family Certhiidae order Artiodactyla family Carangidae family Echimyidae family Ictaluridae order Galliformes order Perissodactyla family Anguillidae order Passeriformes order Pelecaniformes family Siluridae family Muridae order Chiroptera family Picidae order Lagomorpha family Moronidae family Triglidae order Eulipotyphla family Atherinidae order Gruiformes family Fringillidae family Alcedinidae family Scolopacidae class Aves family Talpidae family Camelidae family Xenocyprididae order Carnivora family Viverridae family Sciuridae family Recurvirostridae family Percidae family Gobionidae family Emydidae order Salmoniformes class Mammalia family Engraulidae family Esocidae family Blenniidae family Soricidae family Poeciliidae family Phasianidae order Mugiliformes order Atheriniformes family Acheilognathidae family Turdidae family Psittaculidae family Paridae family Ardeidae family Salmonidae family Salamandridae family Anatidae class Amphibia family Cyprinidae order Osmeriformes order Gobiiformes family Ranidae family Bufonidae family Tincidae family Alosidae family Troglodytidae family Laridae family Corvidae family Leporidae family Leuciscidae order Syngnathiformes order Beloniformes order Scorpaeniformes family Muscicapidae kingdom Animalia family Canidae order Perciformes family Phalacrocoracidae order Cetartiodactyla family Castoridae order Anura order Esociformes family Gobiidae family Nemacheilidae family Suidae family Discoglossidae class Actinopterygii family Vespertilionidae order Chelonii order Accipitriformes family Pandionidae family Sturnidae order Cyprinodontiformes family Clupeidae order Siluriformes order Urodela order Columbiformes family Gliridae order Charadriiformes family Cottidae family Myocastoridae order Cypriniformes family Sparidae family Prunellidae family Accipitridae family Scombridae order Psittaciformes family Alaudidae order Anguilliformes order Rodentia family Rallidae family Syngnathidae family Cervidae order Strigiformes order Coraciiformes order Piciformes family Belonidae family Soleidae family Mustelidae order Pleuronectiformes family Centrarchidae order Clupeiformes family Alytidae family Cricetidae family Cisticolidae family NA family Equidae unknown Olivier Gimenez CEFE https://orcid.org/0000-0001-7001-5142 Simon Lacombe CEFE https://orcid.org/0009-0005-8767-989X Study design and site selection Sampling sites were selected along the Lez River and its tributaries (Hérault, southern France) in order to cover a gradient of anthropogenic pressure, from urban to peri-urban and more natural river sections. All sites were georeferenced and revisited according to the monitoring design. Field surveys of presence signs (spraints and tracks) Standardized field prospections were conducted along riverbanks and riparian habitats to detect otter presence signs. When spraints, footprints, or other diagnostic indices were observed, their location, date, and time (when available) were recorded, along with observer identity and field comments (e.g. freshness, size, substrate). Each record was later standardized as an occurrence. Camera trapping Motion-triggered camera traps were deployed at selected locations such as river crossings, banks, or frequently used paths. Cameras recorded continuously during deployment periods. Videos and images were reviewed, and species identifications were validated based on visual evidence. Each detection event was formatted as a standardized occurrence with date, time, and geographic coordinates. Environmental DNA (eDNA) sampling Water samples were collected at monitoring sites following harmonized protocols. Samples were analyzed using metabarcoding techniques by a specialized laboratory (e.g. SPYGEN). Species detections were converted into occurrence records using presence/absence coding at the site × taxon level, with environmental DNA specified as the identification method. Taxonomic standardisation Taxa were standardized against national taxonomic references (e.g. TAXREF). When identification to species level was not possible, records were retained at the most reliable taxonomic rank. Data harmonisation and quality control All records underwent validation procedures including coordinate verification, date formatting, and consistency checks across datasets and sampling methods. Occurrence status was harmonized (present vs non-detected where applicable), and duplicates or inconsistencies were corrected. Genetic analyses of spraints Additional genetic analyses were performed on some spraint samples (e.g. individual identification, origin, diet). These genetic results are not included in this published dataset, which contains only field detection data. The study was conducted along the Lez River and its tributaries in southern France (Hérault department). Sampling sites include peri-urban and urban freshwater ecosystems characterized by varying levels of anthropogenic pressure. The objective is to better understand Lutra lutra; a protected species and indicator of the quality of aquatic environments; dynamics of establishment in a highly anthropized environment. Data were collected between 2023 and 2025 as part of an ongoing long-term monitoring programme. Data were collected using a combination of non-invasive monitoring methods targeting the European otter and associated vertebrate fauna. Spraint surveys: Standardized field prospections were conducted along riverbanks and riparian habitats to detect and record otter spraints and other field signs. Camera trapping: Motion-triggered camera traps were deployed at selected sites to record wildlife activity. Video and photographic detections were reviewed for species identification. Environmental DNA: Water samples were collected and analyzed using environmental DNA metabarcoding techniques to detect the presence of otters and other vertebrate taxa. All methods were implemented following standardized protocols to ensure comparability across sites and sampling periods. Olivier Gimenez https://orcid.org/0000-0001-7001-5142 author Simon Lacombe https://orcid.org/0009-0005-8767-989X author 2026-02-17T10:08:05.898+00:00 dataset Gimenez O, Lacombe S (2026). Study of the European otter (Lutra lutra) in the watersheds of the Montpellier metropolitan area. Version 1.0. Centre d’Ecologie Fonctionnelle & Evolutive (CEFE). Occurrence dataset. https://ipt.gbif.fr/resource?r=otter_gimenez&v=1.0 Olivier Gimenez, Simon Lacombe, Louis Barbu, Yann Raulet, Vincent Sablain, et al.. Étude du retour de la Loutre d'Europe Lutra lutra (Linnaeus, 1758) sur le fleuve Lez (fleuve côtier, Hérault, France) grâce aux méthodes non-invasives de suivi des populations et une collaboration étroite entre structures académiques et territoriales. 2024. ⟨hal-04725018v2⟩