Personality and predation risk in urban-nesting mountain chickadees

Urbanization is changing natural landscapes worldwide, pushing species to quickly acclimate or adapt if they are to survive in urban environments. Urban living means dealing with an increase in chemical pollutants, higher rates of pathogen transmission, and different predator landscapes than are found in rural environments. Mountain chickadees (Poecile gambeli) are considered urban adapters, readily nesting in both urban and rural environments without suffering apparent reproductive costs. However, whether urban-nesting chickadees are successful in these environments due to differences in personality between urban and rural birds remains untested. For example, urban birds may exhibit low neophobia and high boldness, allowing them to better cope with the challenges of urban environments. To test for differences in anti-predator behaviour and neophobia between urban and rural birds, we examined the behavioural responses of urbanand rural-nesting mountain chickadee females that were presented with a predator (squirrel model) and a novel object (red plastic cup) at the nest. We found that urban-nesting mountain chickadees displayed less neophobic behaviour than the rural-nesting mountain chickadees, readily reentering the nest and essentially ignoring the novel object on the nest box. Urban-nesting mountain chickadees in our study also displayed more aggressive behaviour than rural-nesting mountain chickadees when presented with a model of a predator. Together, these results suggest that bolder, less neophobic birds may disproportionately settle in urban environments, a pattern that may aid in mountain chickadees’ ability to readily and successfully nest in urban environments.