From field to lab, facilitating non‐invasive genetic survey. Lessons from an arctic bird living at the edge, the rock ptarmigan in the French Alps

The rock ptarmigan Lagopus muta is an elusive species whose monitoring is hindered by its cryptic behavior and the difficulty in accessing its high‐elevation habitats. Although non‐invasive genetic sampling offers a promising alternative, its effectiveness can be constrained by DNA degradation and environmental conditions. However, the feasibility of using late spring fecal samples to genetically identify individual rock ptarmigans in the French Alps remains poorly evaluated, despite the logistical advantages offered by this period. To address this gap, we collected 338 fecal samples over two spring seasons in the French Alps and genotyped at 19 microsatellite loci. We examined the impact of sample freshness and weather conditions on genotyping success and error rates, and we tested how the use of non‐invasive samples can be optimized. For the field phase, our results highlight the importance of collecting well‐preserved, fresh fecal samples, preferably on dry days and on snow‐covered ground. For the laboratory phase, some procedures require optimization for fecal samples containing uric acid. Overall, this study emphasizes the critical role of study design in non‐invasive genetic monitoring initiatives. By applying appropriate field sampling guidelines and laboratory protocols, fecal samples can yield high‐quality genetic data, even in late spring in the French Alps.