The effect of predation pressure and predator adaptive foraging on the relative importance of consumptive and non-consumptive predator net effects in a freshwater model system

An important challenge in community ecology is identifying the functional characteristics capable of predicting the nature and strength of predator effects on food webs. We developed an individual-based model, based on a shallow lake model system, to evaluate the total, consumptive, and non-consumptive indirect effect that predators have on basal resources when the predators differ in their foraging types (active adaptive foraging or sedentary foraging). Overall, both predator types caused similar total indirect effects on lower trophic levels. However, the nature net effects of predators diverged between predator foraging types. Active predators caused larger non-consumptive effects, relative to the total indirect effect, irrespective of predation pressure levels. On the other hand, sedentary predators caused larger non-consumptive effects for lower predation pressure levels, but consumptive effects became more important as predation pressure increased. Our simulations showed that the reliance on a particular mechanism driving consumer-resource interactions is altered by predator foraging behavior and highlight the importance of both prey and predator foraging behaviors to predict the causes and consequences of cascading effects observed in food webs.