Non-Invasive Monitoring of Hazel Dormouse (Muscardinus avellanarius): First Insights on Genetic Data Quality From the First Pilot Study.

Genetic non-invasive sampling (gNIS) methods, which enable DNA extraction from naturally shed materials, offer a powerful, low-impact tool for studying elusive species, minimising disturbance and ethical concerns. However, such approaches require careful assessment of sample quality and data accuracy to ensure reliable genetic results. The hazel dormouse (Muscardinus avellanarius) is an arboreal rodent that plays a crucial role in ecosystems. Despite conservation concerns arising from its low population densities, which are closely linked to habitat quality, it remains poorly understood due to monitoring challenges. This pilot study, conducted in the high Agri Valley (Basilicata, Italy), evaluates a non-invasive genetic sampling protocol for the hazel dormouse using hair-tubes. We investigated the genotyping efficiency, the reliability and informativeness of selected microsatellite markers and the impact of hair sample quantity and trap placement duration on genotyping success and error rates. We used 126 hair tube traps at 14 sampling sites, obtaining reliable genotypes for 14 individuals out of 32 hair samples collected, with a genotyping efficiency significantly affected by both the number of hairs collected and the collecting time interval. The microsatellite marker panel showed a high number of alleles and a low probability of identity, proving to be informative for population monitoring. The results underscore the potential of this non-invasive approach for monitoring elusive and conservation-priority species while highlighting the need to minimise field collection time and optimise trap design to improve DNA quality and genotyping reliability.