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

Résumé 0

Loud noise impacts human and non-human animals’ health and welfare after some hours of exposure. Worried about animals’ life quality, a Civil Inquiry was informed against using a protected area (the Morro do São Bento municipal park) at Ribeirão Preto, SP, Brazil, for public festivities, where there was a zoo. Attending the Public Prosecutor’s request concerning potentially harmful effects on captive and free-living animals in the zoo, thetechnical study reported here was carried out. Two moments were compared –a weekend during an Italian Festival (event, EV) and a weekend with no event (NE)– concerning the sound pressure level in predefined locations within the zoo and behavior in video recordings taken from a sample of captive animals (two ocelots, two curassows, a European deer and a maned wolf). The soundscape in the zoo was monitored with an automatic recorder (Wildlife Acoustics’ Song meter 3). It was found that the peak SPL measure was higher in almost all zoo locations in EV than in NE; the animals changed their activity (spent more time moving throughout the day in EV) and resting patterns (briefer in EV), and the EV soundscape was more diverse across species (intense vocal activity) than in NE, but dominated by alarm calls. The conclusion was that the animals underwent changes in their circadian behavioral patterns related to food intake and resting. Resting and foraging times were directed at self-defense behaviors. The attention of potential stakeholders to animal welfare is urgent since there is no legal regulation protecting non-human ears from damage and life quality, and the animals in the zoo have no chance to avoid noise since they are caged.