Wound healing in the wild: stress, sociality and energetic costs affect wound healing in natural populations.

Ecoimmunologists strive to understand how ecology and evolution shape immunity in natural populations. To date, ecoimmunologists have sometimes struggled to find measures of immunity that can be easily performed in nonmodel systems. One exception is variation in rates of cutaneous wound healing, which is a functionally important, integrative measure of immunity that combines cell-mediated, inflammatory and even some Th2-mediated processes. Here I review what is known about sources of variation in wound healing in wild populations, focusing on two key ecoimmunological questions: How and when does the stress response influence immune function? And how do energetic trade-offs alter immunity? The results indicate that stress and energetic costs can suppress wound healing, but the effects depend on individuals' social and abiotic environments. I also discuss methods to measure wound healing in natural populations and useful directions for future research. Because wound healing has functional significance to organisms, can be measured in diverse species and integrates several immune processes, this measure of immunity is an especially valuable member of the ecoimmunological toolkit.