Meeting Abstract
Anthropogenic ecosystem alterations, such as the introduction of invasive species, are a common perturbation affecting many animals. Such stressors can have fitness-relevant consequences, including for immune function. The eastern fence lizard (Sceloporus undulatus) has been dealing with invasive stinging fire ants (Solenopsis invicta) for over 70 years and exhibit associated morphological, behavioral, and physiological adaptations. We conducted a suite of immune assays on lizards caught from sites with long histories of fire ant invasion and lizards from fire ant free sites. Our results build on earlier findings of suppressed immune function of lizards within fire ant invaded populations to show that some portions of the immune system are affected by a history of fire ant invasion (e.g. cell-mediated immunity), whereas others remain unaltered (e.g. superoxide production by phagocytes). We also found that lizards from fire ant invaded sites have a higher ectoparasite load than lizards from sites without fire ants, which can also affect immune function. This variability in the responses of different aspects of the immune system to invader-induced stress may reveal which portions of the immune system are most vital to survival, and those that may be sacrificed in times of elevated stress.
