Passive acoustic monitoring as a way to assess daily dynamics of animal activity in urban green areas

Abstract

Fast process of urbanization makes it crucial to include cities in assessment of all global processes. Urban areas on the one hand are subjects to the high levels of anthropogenic influence. On the other hand, urban green areas could provide shelter for some species, inhabiting highly disturbed rural landscapes. The data on daily dynamics of activity is required to assess the impact of noise and light pollution on biodiversity. In this study we have checked the efficiency of passive acoustic monitoring (PAM) in assessing the daily dynamics of animal acoustic activity in city parks. We have identified the acoustic signals of birds on the records and calculated the time of each species acoustic activity. Moreover, we have conducted the classical birds' survey to assess the efficiency of PAM. In order to evaluate the possibility of using acoustic indices to assess daily dynamics of acoustic activity, we have calculated NDSI, BI, ACI and ADI indices for each hour a day. We managed to acoustically detect 70% of species, found by route census by single recorder. NDSI (Normal Difference Soundscape Index) correlates well with total acoustic activity of animals and could be used as indicator for this parameter.