Meeting Abstract
In order to maximize lifetime reproductive success, organisms often must allocate limited energetic resources to life history traits that are important to survival, such as immunity and locomotion. Consequently, trade-offs can occur between traits, depending on the traits’ energetic costs and energy available to each organism. Previous work on green anole lizards reveals that when energy is forced to be allocated to endurance performance via exercise training, the immune system becomes compromised. We tested whether the opposite relationship was true. We predicted that when an organism faces an immune challenge such as infection and/or wound healing, its endurance performance should decrease, with greater immune challenges decreasing performance more. To test this prediction, male and female green anoles were given or not given cutaneous wounds and underwent two rounds of lipopolysaccharide (LPS) or saline injections to induce an integrated immune response. We measured endurance, sprint speed, and bite force before and after each round of injections. We predicted performance to vary in the order: no wound-no LPS > no wound-LPS > wound-no LPS > wound-LPS. However, we found that neither wound healing nor LPS injections affected any performance trait in either males or females after the first injections. However, after the second round of injections, LPS decreased bite force, suggesting a lack of motivation due to sickness behavior.
