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Data for: Little parental response to anthropogenic noise in an urban songbird, but evidence for individual differences in sensitivity
Anthropogenic noise exposure has well-documented behavioral, physiological and fitness effects on organisms. However, whether different noise regimes evoke distinct responses has rarely been investigated, despite implications for tailoring noise mitigation policies. Urban animals might display low responsiveness to certain anthropogenic noise regimes, especially consistent noise (e.g. freeway noise), but might remain more sensitive to more diverse noise regimes. Additionally, whether individuals differ in noise sensitivity is a rarely explored issue, which is important to fully understand organismal responses to noise. To address these knowledge gaps, we used a field experiment to measure how urban great tits (Parus major) altered parental behaviors in response to two noise regimes: consistent freeway noise, and a diverse anthropogenic noise regime that incorporated variability in noise type and temporal occurrence. We also evaluated whether sex, age, or a well-described personality trait, novel environment exploration behavior, were associated with responses to noise, although our power to assess individual differences in responses was somewhat limited. We found no evidence for mean population-level changes in nestling provisioning behaviors during either noise treatment. However, despite this overall canalization of behavior, there was evidence for individual differences in noise sensitivity, particularly during the diverse noise treatment. Females and birds that explored a novel environment more rapidly (fast explorers) reduced nestling provisioning rate more relative to baseline levels than males and slow explorers during the diverse urban noise, but not during the consistent freeway noise. Furthermore, first year breeders and fast explorers displayed larger increases in latency to return to the nest box relative to baseline conditions during the diverse noise only. Results suggest that urban animal populations might become overall tolerant to anthropogenic noise, but that certain individuals within these populations nonetheless remain sensitive to certain types of noise exposure. Methods We exposed great tits (Parus major) breeding on relatively quiet territories within an urban area (Antwerp, Belgium) to anthropogenic noise during the nestling stage and assessed parental responses to noise disturbance. Noise exposure treatments consisted of two types: (1) consistent broadband freeway noise, and (2) a "diverse" noise regime incorporating different anthropogenic noise types that occurred at variable temporal intervals. These noise exposure treatments lasted for 1 h, and were each proceded by a baseline recording in which parental behaviors were assessed in absence of noise disturbance. Noise exposure treatments occurred on adjacent days, or 1-2 days apart. We measured nestling provisioning rate (feeding visits per min), latency to return to the nest box, and the average amount of time spent in the nest box via vieo-recording. We also investigated whether sex, age, or exploratory personality type (measured prior to the noise exposure experiment using a standard test) were related to responses to noise exposure.
Keywords: Biology, Chemistry