Essential steps for establishing a large-scale passive acoustic monitoring for an elusive forest bird species: the Eurasian Woodcock (Scolopax rusticola)

Abstract

In light of global biodiversity loss, comprehensive monitoring of species and biodiversity is fundamental for effective conservation management. Technology-driven approaches, particularly in the field of bioacoustics, have gained importance, with autonomous recording units (ARUs) such as the AudioMoth being a notable example. However, a systematic application of this technology in large-scale passive acoustic monitoring (PAM) schemes is challenging because of a lack of species-specific calibration techniques and information on survey design. Using Eurasian Woodcock Scolopax rusticola as our focal species, we present application-oriented guidelines for testing and implementing a terrestrial, single-species PAM scheme. In this process, we assessed the species-specific detection space of AudioMoths, considering the influence of recording setup and location. ARUs had similar detection rates as a human observer when set up in locations with low vegetation. A further comparative analysis of bioacoustic and traditional roding surveys confirmed the comparability of the two methods. The last step comprised an evaluation of BirdNET as a means of automated species detection. Although BirdNET reliably detected Woodcock occurrence, our results underline the need for rigorous testing of computer-aided data analysis as well as recording hardware before establishing PAM. We demonstrate that low-cost open source ARUs and open access analysis tools can yield results on a par with traditional survey methods, and we provide specific recommendations for PAM for Eurasian Woodcock.