Reciprocal Behavioral Plasticity and Behavioral Types during Predator-Prey Interactions

Abstract

How predators and prey interact has important consequences for population dynamics and community stability. Here we explored how predator-prey interactions are simultaneously affected by reciprocal behavioral plasticity (i.e., plasticity in prey defenses countered by plasticity in predator offenses and vice versa) and consistent individual behavioral variation (i.e., behavioral types) within both predator and prey populations. We assessed the behavior of a predator species (northern pike) and a prey species (three-spined stickleback) during one-on-one encounters. We also measured additional behavioral and morphological traits in each species. Using structural equation modeling, we found that reciprocal behavioral plasticity as well as predator and prey behavioral types influenced how individuals behaved during an interaction. Thus, the progression and ultimate outcome of predator-prey interactions depend on both the dynamic behavioral feedback occurring during the encounter and the underlying behavioral type of each participant. We also examined whether predator behavioral type is underlain by differences in metabolism and organ size. We provide some of the first evidence that behavioral type is related to resting metabolic rate and size of a sensory organ (the eyes). Understanding the extent to which reciprocal behavioral plasticity and intraspecific behavioral variation influence the outcome of species interactions could provide insight into the maintenance of behavioral variation as well as community dynamics.

Behavioral Hypervolumes of Predator Groups and Predator-Predator Interactions Shape Prey Survival Rates and Selection on Prey Behavior

“…Active sea stars tend to capture snails with less pronounced predator avoidance behavior, and sedentary sea stars tended to capture snails with more pronounced predator avoidance behavior (Pruitt et al 2012). Similar associations between the behavioral tendencies of individual predators and the selection gradients they impose on prey behavior have since been identified in several other systems (DiRienzo et al 2013; McGhee et al 2013; Sweeney et al 2013). We thus predicted here that more behaviorally diverse groups of sea stars would kill a larger number of prey because, for any one prey type, there is a greater chance that at least one of the predators present would exhibit a behavioral phenotype that is adept at killing snails of that type.…”

Individual Variability

“…Most research so far has focused on the differences between individuals of one species of predator and prey. However, a deeper understanding of predator-prey interactions will require careful study of how the differences in morphological traits and/or behavioural plasticity of both individual predators and prey affect their relationships (see McGhee et al, 2013 for an example). Scaling up from the population level to communities, where empirical data on the functional responses of multiple interacting species are rare, will however likely remain a major challenge for some time.…”

Individual variation in foraging behavior reveals a trade-off between flexibility and performance of a top predator

“…Additionally, pike would only eat live prey (i.e., would not consume a dead animal or invertebrate when added to the tank; LMP and KEM, personal observation, but see Milinski et al 1997). These particular pikes were used in several different experiments (e.g., McGhee et al 2012, 2013), and this study was simply a modification of the daily feeding protocol required to maintain the pike in the laboratory. Thus, no additional fish were used as prey other than the single fish the pike received as part of their daily feeding regime.…”

“…Specifically, we predicted that individuals that are more flexible and faster to modify a learned behavior will be less efficient foragers on live ecologically relevant prey (three-spine stickleback, Gasterosteus aculeatus ). Pike exhibit consistent individual differences in foraging behavior and diet through time and across ecological contexts (Beaudoin et al 1999; Nyqvist et al 2012; McGhee et al 2013). Interindividual variation in behavioral flexibility could have important consequences for pike population dynamics when faced with changes in the composition and availability of prey species (Venturelli and Tonn 2006; Bolnick et al 2010, 2011).…”