Meeting Abstract
As global change accelerates, species often must adapt quickly or face extirpation or extinction. While adaptive responses may improve fitness under novel selective pressures, they may also maladapt organisms to original environmental conditions, including native predators. Invasive fire ants (Solenopsis invicta) are novel venomous predators of Eastern Fence Lizards (Sceloporus undulatus). Lizards from fire ant-invaded sites flee and twitch in response to potentially lethal fire ant attacks at higher frequencies than lizards from sites uninvaded by fire ants. While we found evidence that this behavior is adaptive in the presence of fire ants, these changes appear maladaptive in the presence of native predators, as lizards from fire ant invaded sites suffered higher mortality in the absence of fire ants. A behavioral shift from reliance on crypsis to increased responsiveness could attract visual predators and reduce probability of survival when attacked. We found that behavioral responses to fire ants are generalized to native ants, suggesting that lizards adapted to fire ant presence may break crypsis often and potentially attract predators. This response to fire ants did not, however, carry-over to affect reactions to a perceived avian predator. We also found support for the costs of this behavioral adaptation in the field: fence lizards from populations exposed to fire ants had significantly higher injury rates than fire ant naïve lizards. Our results suggest a generalized anti-ant behavior may improve survival in the presence of fire ants but reduce fitness in the absence of this invader, potentially due to increased predation by native visual predators. These results inform our understanding of both the consequences and limitations of rapid adaptation.
