Meeting Abstract
The central tenet of life-history theory posits allocation to fitness-related traits reduces the amount of available resources that can be invested into competing traits, resulting in trade-offs. Immunity and whole-organism performance capacity fit within the life-history framework as physiologically costly traits crucial for survival. Life-history trade-offs may occur when the demands of immune traits impinge upon investment in performance traits, and vice versa. Whether shifts in performance capacity occur under such conditions was determined in side-blotched lizards (Uta stansburiana) through comparisons of maximal sprint speed and rates of healing from wounds (i.e., cutaneous biopsies) of various sizes. Energy budget (i.e., food intake) and oxidative stress (i.e., pro-oxidants versus antioxidants) associated with immune and performance investment were also compared among lizards by wound size. Findings herein reveal sprint speeds are not constrained when healing from wounds of increasing sizes. Instead, healing and sprint speed deviate with wound size such that both are concurrently invested when healing from small wounds, at a trade-off for medium wounds, and variably invested for large wounds. Such findings indicate performance expression adjusts according to the demands of an immune challenge, perhaps to offset the energetic and oxidative costs of immunological prioritization. However, energy intake decreases and oxidative stress increases with greater wound size, suggesting components of self-maintenance or long-term survival may become compromised if an immune challenge exceeds a certain magnitude.
