INVESTIGATING BEHAVIORAL VARIATION IN URBAN AND RURAL POPULATIONS OF EASTERN BLUEBIRDS
Urbanization presents animals with unique challenges associated with the effects of human disturbances such as increased noise, light, pollution and proximity to humans. However, increased tolerance of human disturbance can allow individuals to take advantage of beneficial aspects of urban landscapes such as access to resources, less interspecific competition and lower predation. Clumped resources associated with human disturbances characterize urban landscapes and may favor more aggressive males that can defend high quality resources and bolder males that are tolerant of human disturbance. In this study, we investigate how aggression and boldness differs in populations of eastern bluebirds (Sialia sialis) inhabiting urban and rural landscapes. We measured differences in male aggression using a conspecific playback, where closer approach toward the speaker indicates higher aggression. We measured boldness of males in the presence of humans and natural predators by their willingness to approach. We found that males in urban habitats are more aggressive than males in rural habitats and that urban males approached humans and natural predators equally. However, rural birds were less willing to approach a human than to approach a natural predator. Our results suggest that boldness in the presence of humans is not the result of habituation and that anthropogenic disturbance favors aggressive males that are tolerant of humans.
Ballentine, Barbara and Graham, Meghan
"INVESTIGATING BEHAVIORAL VARIATION IN URBAN AND RURAL POPULATIONS OF EASTERN BLUEBIRDS,"
Georgia Journal of Science, Vol. 75, No. 1, Article 50.
Available at: https://digitalcommons.gaacademy.org/gjs/vol75/iss1/50