Landscape use by prey: Bottom-up regulation prevails under reduced
perception of risk
Abstract
Proactive antipredator behavior results from a mental construct of
perceived predation risk, and drives prey’s strategies to avoid being
killed while minimizing constraints to their activities. Under this
reasoning, resource specialists may suppress antipredator strategies to
access scarcely available key resources, while proactive antipredator
behavior should be privileged by generalists or when resources are
abundant. We quantified the relative effects of predation- (top-down)
and resource-driven (bottom-up) constraints to 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.Our results depict a generalized
pattern of predator-prey spatial co-abundance, independent of predator’s
hunting strategy or prey’s importance in the predator’s diet, even
overriding the effects of water and forage availability. Further, we
found prey to have higher activity overlap with the ambush than with the
cursorial predator, with little influence of the season or prey
preference. We failed to detect spatiotemporal proactive antipredator
responses either towards 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, likely relegating prey to
rely on reactive responses to short-term predation risk.