A behavioral syndrome linking boldness and flexibility facilitates invasion success in sticklebacks

Understanding the factors that allow a species to expand their range and adapt to changing habitats is essential for mitigating anthropogenic change. We evaluated how behavior and cognition facilitate colonization of new environments and evolve post establishment during natural biological invasions. Marine threespined sticklebacks are expert colonists with a penchant for invading freshwater environments and rapidly adapting to them. However, the role of behavior in facilitating rapid adaptation in this system has received little attention. By rearing replicate populations of sticklebacks under common garden conditions in the lab, we tested the hypothesis that boldness is favored in dispersers and that neophilia and flexibility are favored in recently-arrived immigrants. We found that dispersing populations comprised bold individuals, while sticklebacks from the invaded region were flexible in their behavior. Moreover, boldness and flexibility were negatively correlated with each another..., ,