The behavior of infected hosts: Behavioral tolerance, behavioral resilience, and their implications for behavioral competence

Abstract

AbstractAn infected host’s behavior should critically impact its own fitness and that of its parasites. However, the ubiquitous variation in behavior within and among individuals and the difficulty of linking behavioral observations directly to fitness make studying this phenomenon challenging. This chapter discusses how behavioral observations before, during, and after infection can yield valuable insights. In doing so, it considers the variation in, quantification of, and relationships among “behavioral tolerance,” a host’s ability to maintain fitness-enhancing behavior during infection; “behavioral resilience,” a host’s ability to regain pre-infection expression of fitness-enhancing behavior; and “behavioral competence,” the behavioral component of the probability that a host contributes to ongoing transmission. Analyzing these relationships is critical to revealing how behavior-parasite feedbacks drive disease spread and host–parasite coevolution.