Landscape use by prey: Bottom-up regulation prevails under reduced predation risk

Abstract

Resource specialist herbivores may suppress antipredator strategies to access scarcely available key resources, while proactive antipredator behaviors should be favored by generalists or when resources are abundant. We quantified the relative effects of predation- (top-down) and resource-driven (bottom-up) constraints on spatiotemporal patterns of landscape use by a prey community in a dynamic system under low predator abundance, and investigated how prey manage the risk posed by predators with different hunting strategies. We fitted Royle–Nichols co-abundance models to camera-trapping data collected between 2017 and 2019 in Bicuar National Park (Angola), to assess spatial association/segregation across predator–prey dyads, while accounting for the effects of water and food availability during dry and wet seasons. We further estimated pairwise seasonal differences in diel activity overlap between predator and prey. We failed to detect spatiotemporal proactive antipredator responses either toward the cursorial or ambush predator. The community-wide predator–prey association patterns we found support that predation pressure is insufficient to displace prey from their preferred habitats or to adjust their endogenous clock, and support predominantly bottom-up regulated behaviors. We suggest that, in landscapes where predator density is low, limited perception of risk may prevent the employment of proactive antipredator behavior.