Fear of the human ‘super predator’ reduces feeding time in large carnivores

Abstract

Large carnivores' fear of the human 'super predator' has the potential to alter their feeding behaviour and result in human-induced trophic cascades. However, it has yet to be experimentally tested if large carnivores perceive humans as predators and react strongly enough to have cascading effects on their prey. We conducted a predator playback experiment exposing pumas to predator (human) and non-predator control (frog) sounds at puma feeding sites to measure immediate fear responses to humans and the subsequent impacts on feeding. We found that pumas fled more frequently, took longer to return, and reduced their overall feeding time by more than half in response to hearing the human 'super predator'. Combined with our previous work showing higher kill rates of deer in more urbanized landscapes, this study reveals that fear is the mechanism driving an ecological cascade from humans to increased puma predation on deer. By demonstrating that the fear of humans can cause a strong reduction in feeding by pumas, our results support that non-consumptive forms of human disturbance may alter the ecological role of large carnivores.

Safety first: seasonal and diel habitat selection patterns by red deer in a contrasted landscape

“…Animal space‐use patterns result from the need to balance access to limiting resources with avoidance of competition (Vanak et al ., ), predation risk (Thaker et al ., ; Wirsing & Ripple, ; Lone et al ., ; Moll et al ., ), or human disturbance (Ciuti et al ., ; Kuijper et al ., ; Stabach et al ., ; Bötsch, Tablado & Jenni, ; Müller et al ., ; Smith et al ., ). Spatially heterogeneous landscapes provide solutions to the forage‐safety trade‐off when animals can access risky but energetically rewarding patches, or safer patches with lower resources abundance or quality (landscape of fear) (Bjørneraas et al ., ; Basille et al ., ; Padié et al ., ; Filla et al ., ).…”

Nonconsumptive effects of hunting on a nontarget game bird

“…Anthropogenic disturbances can have profound effects on wildlife by eliciting fear and altering behavior (Gaynor, Hojnowski, Carter, & Brashares, 2018). It has been recognized that such human-driven disturbances can have cascading effects across food webs (Smith et al, 2017;Smith, Wang, & Wilmers, 2015). It has been recognized that such human-driven disturbances can have cascading effects across food webs (Smith et al, 2017;Smith, Wang, & Wilmers, 2015).…”

Anthropogenic influences on primate antipredator behavior and implications for research and conservation

“…In their preliminary experiments, the authors successfully used speakers triggered by motion sensors to play sounds of human hunters at Bwindi Forest, Uganda, to gauge illegal hunting pressure without observer interference. This system has also allowed researchers studying cougar ( Puma concolor ) responses to anthropogenic sounds to measure whether fear of humans could alter their risk perception and predation behavior, resulting in a human‐induced foraging cascade (Smith et al, ). This system could also be a powerful way of testing fear responses across a range of taxa going forward.…”

“…It is also possible to use these same behaviors as indicators of fear with information on conflict/hunting risk from humans (Bryson‐Morrison, Tzanopoulos, Matsuzawa & Humle, ; Lindshield, Danielson, Rothman, & Pruetz, ). Yet, a direct observation also potentially biases antipredator studies because many carnivores actively avoid proximity to humans (Boesch, ; Isbell & Young, ; Smith et al, ; van Cleave et al, ). When comparatively tolerant prey species can perceive and exploit this increase in safety near observers or even human infrastructure, it is known as the “human‐shield effect” (Berger, ; Sarmento & Berger, ).…”