Date Awarded


Document Type


Degree Name

Master of Science (M.Sc.)




Daniel A Cristol

Committee Member

John P Swaddle

Committee Member

Matthias Leu


We asked whether anthropogenic noise and animal personality interact to influence the settlement patterns and parental behaviors of individual eastern bluebirds (Sialia sialis) in a suburban landscape. Our hypothesis was that individuals with bold-type personalities would be less sensitive to noise pollution because they are more risk-tolerant. We collected repeated measures of neophobia, aggression, and nestling feeding rate in adult bluebirds while manipulating the sound environment at nest boxes. First, we added a recording of traffic noise during the nestling stage. We found that when exposed to experimental noise, aggressive females had higher feeding rates than less-aggressive females. Individual bluebirds were moderately repeatable in aggression and neophobia, but the two behaviors did not correlate to form bold-type and shy-type personalities. In a second experiment, we manipulated the noise environment during territory establishment, nest-building, and egg-laying. We found that less-aggressive females tended to settle in noise-treated nests, and these females delayed egg-laying by an average of four days, although this was not statistically different from controls. These results suggest that female aggression level is important for mediating the effects of anthropogenic noise pollution on this population bluebirds by influencing spatial arrangement and noise exposure, by directly delaying egg-laying, and by influencing nestling feeding rate. By identifying the role of personality in mediating human impacts on animal populations, we can implement more finely tuned conservation and management programs.




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