Traffic noise decreases nestlings’ metabolic rates in an urban exploiter
Résumé
High levels of anthropogenic noise produced in urban areas are known to negatively aff ect wildlife. Although most research
has been focused on the disturbances of communication systems, chronic noise exposure can also lead to physiological
and behavioural changes that have strong consequences for fi tness. For instance, behavioural changes mediated by
anthropogenic noise (e.g. quality of parental care) may alter development and could infl uence nestling phenotype. We
tested if nestling metabolism was infl uence by traffi c noise in an urban exploiter, the house sparrow Passer domesticus .
We experimentally exposed breeding house sparrows from a rural area to a playback of traffi c noise and we examined
the impacts of this experimental procedure on metabolic rates and morphology of nestlings. We did not fi nd an eff ect of
traffi c noise on the morphology of nestlings. Surprisingly, we found that disturbed nestlings had overall lower metabolic
rates and mass-adjusted metabolic rates than undisturbed birds. Our results suggest a specifi c eff ect of noise exposure
per se, rather than an indirect eff ect of anthropogenic noise through the quality of parental care. Both the proximate
mechanisms and the ultimate consequences of such metabolic changes on nestlings remain unknown and deserve future
experimental studies.