We, the disturbing animal: effects of anthropogenic noise in a Brazilian zoo

Resumen

The negative effects of loud anthropic sounds on non-human health and welfare urges attention. We report here the results of a technical study we conducted attending a Public Prosecutor’s request at Ribeirão Preto, SP, Brazil. A Civil Inquiry informed against nocive effects of human concentration on captive and free-living animals around the municipal zoo. The zoo is part of a natural protected area that paradoxically was used as a locale for public festivities. We aimed to compare two weekends, one of a traditional Italian event (EV) and another with no event (NE), and check sound level and behavioral changes in a sample of captive animals and in the soundscape. We employed three procedures: (1) Sound Pressure level (SPL) assessment at different localities; (2) Comparative behavior analysis; and (3) Soundscape description. Our results provided cues of how the festivities may be affecting free-living animals in the APA Morro do São Bento and captive ones. Peak SPL exposure was higher in EV in almost all the localities of the zoo; the six monitored individuals (two ocelots, two crassow, the European cervid and the maned-wolf) changed their activity and resting patterns and the soundscape was more diverse and intense in vocal activity than in NE.