Infection avoidance behaviors across vertebrate taxa: Patterns, processes, and future directions

Abstract

AbstractAn infected animal can behave, smell, sound, and look very different from a healthy version of itself. The same is true when comparing habitats, food, or water sources contaminated with parasite infectious stages to their uncontaminated counterparts. All these differences provide cues or indications of disease risk and thus allow uninfected animals to modify their behaviors in ways that alter disease transmission. This chapter focuses on prophylactic behaviors: host behaviors that reduce the risk of infection. It provides an overview of how infection avoidance behaviors are triggered, then summarizes the avoidance behaviors known to occur in vertebrates, giving special attention to non-mammalian taxa, which are less represented in the literature. Repercussions of avoidance behaviors can include fitness trade-offs under some circumstances where predation risk is increased, or opportunities for nutrition, growth, or reproduction are diminished. Thus, like balanced immune responses, optimal behaviors may not be those that provide the greatest pathogen avoidance. The chapter outlines knowledge gaps and future priorities for research in the study of behavioral avoidance across taxa and discusses how trade-offs associated with behavioral avoidance may be altered under global change.