Behavioral Adaptations to Invasive Species: Benefits, Costs, and Mechanisms of Change

Invasive species are a major conservation concern but provide an opportunity to examine the mechanisms and consequences of behavioral adaptation. Invasive species can act as novel predators, prey, and competitors; impose stress on species they encounter; and alter habitats. Behavior is often plastic and therefore is one of the first traits to respond to environmental perturbations. Here we illustrate behavioral adaptations to invasive species, primarily using a system of invasive fire ants that act as a novel predator on and prey for a native lizard and placing this in the context of other research. We show that behavioral adaptations to invasive species can increase fitness in the face of associated challenges and opportunities, but can expose adapted individuals to new pressures or maladapt them to previously existing selective pressures. As a result, behavioral adaptations to invasive species can be associated with changes in other traits, such as morphology or physiology, that either enhance the effectiveness of the behavior itself or increase fitness in the face of new pressures caused by the altered behavior.