Automatic devices allow for effective monitoring of Western Capercaillie leks at the edge of a contracting refugium

Lek surveys have been widely used to monitor Western Capercaillie Tetrao urogallus populations, with ongoing surveys in the Pyrenees revealing a significant decline over the past three decades. However, traditional surveys used to derive direct official data – walk‐based and hide‐based – have not yet been compared with modern camera trapping or bioacoustic methods in low‐density areas. Here, we provide the first assessment of the performance of both traditional and modern survey methods in tracking Western Capercaillie numbers in the Catalan Pre‐Pyrenees, the southernmost populations of western Europe. While traditional walk‐based surveys underestimated male abundance at leks, hide‐based surveys, camera trapping and acoustic devices proved to be equally effective, with the latter two offering labour‐saving advantages and additional insights into lek dynamics, making them more effective options for long‐term monitoring of declining Capercaillie populations.