The timid invasion: Behavioral adjustments favor range expansion in a non-native rodent

In biological invasion processes animal behavior moderates the success of invasive species, and the native fauna's ability to adapt. The importance of behavioral syndromes and flexibility of invading species for invasion success remains debated. We investigated behavior of rodents, the bank vole (Myodes glareolus) currently invading Ireland, and the native wood mouse (Apodemus sylvaticus) that declines with vole invasion, at replicated sites at the core, the edge of the invasion, and pre-invasion. We found that individual rodents varied consistently in risk-taking behaviors. Mice individuals did not behave differently between invasion zones. Vole individuals were more careful and also more flexible at the invasion edge, compared to the core. The ability to develop timid and flexible phenotypes may contribute to the invasion success of rodents worldwide. ### Competing Interest Statement The authors have declared no competing interest.