Simulated fireworks constitute behavioral, but probably not physiological stressors in captive Atlantic canaries Serinus canaria

Brief, loud sounds are known as impulsive noise and can trigger behavioral reactions, increase energy demand, and interrupt the routine activities of organisms. However, few studies evaluate the potential energetic costs of impulsive noise on birds, under controlled conditions, hindering our understanding of its real impacts. Here we experimentally evaluate how impulsive noise affects individual physiological and behavioral responses, potentially inducing energetic costs, in canaries Serinus canaria. We tested the hypothesis that impulsive noise produces behavioral and physiological activation. We expected increased levels of circulating corticosterone and glucose, along with locomotor activities when canaries were exposed to simulated fireworks noise compared to background sound. Contrary to our predictions, no effect of simulated fireworks on circulating corticosterone or glucose concentrations was identified. However, when canaries were exposed to simulated fireworks, they increased the frequency of startle reflexes, jumps, and calls, but decreased the number of horizontal movements on the perch and self-grooming. We propose that birds were aware of the simulated fireworks noise, and ready to react physically, but the stimulus did not elicit a strong physiological response under the experimental setting used in this study.