Sound amplitude (dB) of male Western Capercaillie Tetrao urogallus calls

Knowledge of the true amplitude (dB) of sound signals is necessary for calculating how far they can travel and the distance at which they can be detected, two crucial aspects for plan ning bio-acoustic sampling protocols, particularly if endangered species such as the Western Capercaillie are involved. In order to be able to measure the true emission amplitude of male Western Capercaillie Tetrao urogallus calls, we recorded 90 repetitions of the call of a single male using a calibrated microphone located 1 m away from the bird. In this way, we were able to determine for the first time the true amplitude of a calling male Western Capercaillie in the Alt Pyrenees Natural Park, which turned out to be 67.68 ± 0.83 dB. Considering the char acteristics of our microphone, this gives an average maximum detection distance of 174.8 m, important information for optimising future bio-acoustic detection and monitoring studies.