A Scoping Review: The Effect of Anthropogenic Noise on Animal Welfare in Zoological Settings

With zoological institutions placing greater emphasis on improving animal welfare, there has been more research studying the impact of animal welfare, including correlation with increased visitors. Some studies focus on the total effect of visitor presence and behaviours impacted, whereas others highlight how noise from visitors and other events impacts animal behaviour and welfare. This scoping review was conducted to determine the impact of anthropogenic noise on animal welfare in zoological settings and identify knowledge gaps. Starting with an initial pool of 1608 articles, almost all publications in this review (n = 31) were published from 2014 to 2025, indicating the area is still a niche to be further explored. Most studies focused on mammalian species (n = 22, particularly non-human primates), followed by avian species (n = 14) and reptiles (n = 3). Increased vigilance was the most common behaviour documented (n = 9). Thirteen publications suspected a negative welfare impact, while the remaining publications either found no substantial impact, could not determine impact, or did not address welfare directly. Fourteen publications recommended improving public education, sound barriers or increasing animals' ability to choose a different location. Certain species and taxa, such as teleosts and reptiles in glass enclosures, lack representative studies on how anthropogenic noise affects their welfare. Further research that focuses on understanding the impact of noise on animal wellbeing could educate the public, allow restructure of habitats to accommodate animal needs and inform welfare assessments, which all can improve the welfare of animals in zoological settings.