Maternal Personality May Mitigate The Negative Impacts Of Anthropogenic Noise On A Free-Living Bird

Although the effects of anthropogenic noise pollution on wildlife populations are well documented, little research has focused on the importance of animal personality in mitigating these impacts. Bold individuals may be less likely to suffer than meek individuals from such disturbance. In the present study, I tested whether the personality type of parents can mitigate the negative effects of traffic noise on reproductive output, nestling growth and physiology using a wild population of tree swallows (Tachycineta bicolor). I randomly assigned nests to control versus an experimental traffic noise treatment of 65 dBA at a field site with an average ambient noise of 49 dBA. I quantified personality along a bold to meek spectrum by presenting breeding adults to a stimulated intrusion of a nestling predator. I measured parental fitness as number of offspring fledged, nestling mass, and nestling stress. My results suggest that personality type can mitigate the negative impacts of anthropogenic disturbance on reproductive parameters in birds. If bolder parents achieve higher fitness in noisy environments, human encroachment may be selecting for bolder phenotypes. Assessment of animal personality may improve our understanding of how animal populations will respond to anthropogenic change.