Behavioural shifts of bats during urban music festivals

Abstract The impact on wildlife of large‐scale outdoor music events held in urban green spaces remains poorly understood. Bats are a taxon of focus for evening events, because of their protected status, nocturnality, sensitivity to artificial lighting, and reliance on sound for navigation and foraging. While experimental field studies have singly demonstrated the effects of artificial night‐time lighting and noise on bat activity, studies made during actual music events, associated with unusually high levels of both artificial lighting and noise, are lacking. In this study, we deployed passive acoustic detectors within an urban parkland to monitor bat activity over a 23‐night period, during which two large weekend concert events were held. Nine bat species were recorded. Activity minutes were calculated for all bats and some species groups, and the effect of concerts, alongside several abiotic variables, were measured. Total bat activity was not depressed on concert nights, but total bat activity was reduced during concert hours compared with the same times on nights without concerts. This was significant at the species level for Pipistrellus pipistrellus and Myotis species, with the latter also showing a marginally significant delay in peak activity on concert nights. We suggest that the reduction and delay in bat activity observed during concerts may impair bat foraging success with potential implications for fitness. Solutions. We propose practical solutions to reduce these risks, such as a better‐informed placement and timing of urban outdoor concerts away from important bat habitats and outside the breeding season.