One step at a time: Evaluating Western Capercaillie (Tetrao urogallus) space use after translocation

The Western Capercaillie (Tetrao urogallus) is a highly sensitive forest grouse species facing population declines in Western Europe. In an effort to reinforce its population in the Vosges Mountains, nine adult Capercaillie (five males and four females) were translocated from Norway to the Grand Ventron National Nature Reserve, France, in April 2024. Each individual was fitted with a GPS tag to monitor their post-release movements. This study presents the first insights into the space use of translocated Capercaillie, analyzing home range dynamics, movement patterns, and individual behavioral variability over a nine-month period. Results revealed a distinct post-release exploration phase, characterized by large home ranges and increased movement during the first months, followed by stabilization in winter. Individual variation was evident, with some birds settling near the release site while others exhibited prolonged exploratory behavior, which was associated with lower survival. Movement directionality suggested a quick adaptation to the local landscape, with birds favoring ridge-oriented dispersal. These findings provide valuable information for future Capercaillie translocation programs, emphasizing the importance of monitoring spatial behavior to assess adaptation and survival.