COS 181-3 - Disentangling the role of predator hunting mode, spatial domain size, and habitat complexity: An examination of consumptive and nonconsumptive effects

Abstract: Predator-prey interactions are a fundamental part of community ecology, yet the relative importance of consumptive and nonconsumptive effects (defined as a risk-induced response which alters prey fitness) is not resolved. Theory suggests that the emergence and subsequent predominance of consumptive or nonconsumptive effects depends on the habitat complexity as well as predator hunting mode and spatial domain sizes of both predator and prey, but their relative influence on the outcome of predator-prey interactions is unknown. In this paper, we use the agent-based modeling program NetLogo to simulate predator-prey interactions for three hunting modes—sit-and-wait, sit-and-pursue, and active—and large versus small spatial domain sizes for both predators and prey. We study (i) how hunting mode and spatial domain size interact to influence the emergence of consumptive or nonconsumptive effects, and (ii) when nonconsumptive effects do dominate, how hunting mode and spatial domain separately or additively determine prey shifts in time, space, and habitat use. Our results indicate consumptive effects only dominated for active predators when prey habitat domains overlapped completely with the predator’s spatial domain, and when sit-and-wait and sit-and-pursue predators and their prey both had large spatial domains. Prey were most likely to survive when they shifted their time, but most frequently shifted their habitat. Our paper bridges theory and practice to better understand the underlying mechanisms which drive consumptive or nonconsumptive effects to be most dominant. These results have implications towards theoretical and applied ecology, as well as conservation management.