Ecophysiological effects of predation risk; an integration across disciplines

Abstract

integration of physiological responses has received less attention. This is the subject of this special issue.Prey physiological responses are important at all stages of the predator–prey interaction. They are a major part of the prey’s primary, fight or flight, response, are mechanis-tic drivers of behavioral and morphological changes, help prepare prey for future attack, and secondarily respond to changes caused by primary responses. We are beginning to understand how, in the initial steps of predator detection, sensory systems, such as visual and olfactory ones, may act synergistically to gather information regarding risk (Kats and Dill 1998; Hartman and Abrahams 2000). Following detection, the physiological status of the prey (Koivula et al. 1995; Martin and Lopez 1999), prey genotype (Den-nis et al. 2010), and personality (Sih et al. 2004) influence whether and how they respond. Physiological responses also aid in defense once the predator initiates attack. For example, tadpoles previously exposed to predator cues have adaptive morphological changes linked to elevated stress hormone levels giving them an advantage in escap-ing predation (Hossie et al. 2010), dragonfly predators select for higher arginine kinase enzyme that powers faster swimming speed and escape performance in damselfly prey (Strobbe et al. 2010), and caterpillars can increase digestive efficiency to compensate for reductions in feeding (Thaler et al. 2012). Finally, parental exposure to predation risk can influence offspring behavior, morphology, and physiol-ogy (Agrawal et al. 1999; Sheriff et al. 20092010, ; Storm and Lima 2010; Zanette et al. 2011) and these effects may lead to adaptive phenotypes dependent upon the match between the maternal and offspring environment (Sheriff and Love 2013). Given that the primary response of prey to the immediate threat of predation is the “stress response” (Sapolsky et al. 2000) and central to this is the activation of the hypothalamic–pituitary–adrenal axis, much work has