Negotiating multiple cues of predation risk in a landscape of fear: what scares free‐ranging brushtail possums?

Abstract

AbstractHerbivores live in a landscape of fear and must incorporate danger in their foraging decisions, balancing their need of food and safety using a variety of cues to assess the risk of predation. These cues can either be direct (i.e. signalling the possible presence of a predator) or indirect (i.e. linked to the likelihood of encountering a predator). How then do herbivores negotiate these multiple cues in the landscape? And which type of cues do foraging herbivores use to assess variation in predation risk? We examined these questions by investigating the foraging responses of a free‐ranging marsupial herbivore, the common brushtail possum Trichosurus vulpecula to perceived predation risk. We found that indirect habitat‐related cues of predation (i.e. feeder location) consistently influenced foraging, while other more variable indirect (i.e. illumination) and direct cues (i.e. predator odour) did not. Giving‐up‐density at above‐ground feeders was always lower than at on‐ground feeders. Possums spent more time and foraged more at the above‐ground feeders than at the on‐ground feeders. Our results demonstrate that when multiple cues are present, varying in the accuracy of the information they provide about predation risk, possums respond to habitat‐related cues. Possums manage risk by modifying behaviours, reducing time spent foraging in areas where potential risk is perceived as high. Thus, when the location of a predator at a certain point in time and space is unknown, and food demands are high, habitat‐related cues are a safe choice to assess predation risk, with reliable returns for free‐ranging herbivores.