Unveiling the genetics of Eurasian Lynx (Lynx lynx) in France: Insights for conservation in the Jura and Northern Alps

Fifty years after its reintroduction in Switzerland and natural recolonisation of France, the Eurasian lynx ( Lynx lynx ) continues to face conservation challenges. In addition to major threats such as illegal killing and vehicle collisions, the small number of founder individuals and the isolation of the Jura and Alpine populations contributed to low genetic diversity, a pattern also observed in other reintroduced populations across Europe. Using non-invasive scat samples collected between 2019 and 2024 through a citizen science network, we aimed to conduct a comprehensive genetic survey of Eurasian lynx in the Jura Mountains and Northern Alps of France, focusing on genetic diversity and structure. Analyses of mitochondrial DNA and 18 microsatellite markers revealed a complex genetic pattern: while genetic structuring and diversity suggest ongoing gene flow within the study area, the lack of mitochondrial diversity, combined with the population’s isolation, points to a persistent founder effect. These findings support recent scientific recommendations, informed by extensive modelling, that call for genetic reinforcement. Such an intervention should be combined with efforts to improve population connectivity, reduce human-induced mortality, strengthen transboundary cooperation, and enhance social acceptance, for which citizen science could play a valuable role in both monitoring and public engagement. The results of this study should be incorporated into the forthcoming second National Action Plan for Eurasian lynx conservation in France, to ensure effective and science-based decision-making.