The Parc Naturel Régional des Ballons des Vosges (PNBV) has been carrying out research over the last few years to (re)discover populations of species at risk of extinction: the European Pygmy-Owl (Glaucidium passerinum), the Bull Bush-Cricket (Polysarcus denticauda) and the Parti-coloured bat (Vespertilio murinus). The chosen method consists of recording (audible and ultrasonic) sounds using high-frequency sampling detectors. Inventories are carried out during active listening sessions and, above all, by deploying passive automatic recorders (Audiomoth) under targeted conditions, to maximize the probability of contact with the species sought.

These acoustic recordings produce a large number of sound files (.wav format). It’s very tedious to process the analysis manually in the absence of an automated computerized procedure for searching for these species. Given the exploratory and innovative nature of these surveys, there is no 'turnkey' system for analysing the numerous files generated for these species. However, the recent development of various analysis tools dedicated to bats means that we can easily envisage the development of an automated sorting procedure adapted to the search for the species targeted by the Parc, including birds and orthopterans.

This report is the fruit of Ecofirst's work in this context. The clear objective was providing the PNBV with a reproducible survey methodology, including both the ideal settings for the recorders and tools for analysing the recordings, enabling the 3 target species to be detected as effectively as possible.