The fear large carnivores inspire, independent of their direct killing of prey, may itself cause cascading effects down food webs potentially critical for conserving ecosystem function, particularly by affecting large herbivores and mesocarnivores. However, the evidence of this has been repeatedly challenged because it remains experimentally untested. Here we show that experimentally manipulating fear itself in free-living mesocarnivore (raccoon) populations using month-long playbacks of large carnivore vocalizations caused just such cascading effects, reducing mesocarnivore foraging to the benefit of the mesocarnivore’s prey, which in turn affected a competitor and prey of the mesocarnivore’s prey. We further report that by experimentally restoring the fear of large carnivores in our study system, where most large carnivores have been extirpated, we succeeded in reversing this mesocarnivore’s impacts. We suggest that our results reinforce the need to conserve large carnivores given the significant “ecosystem service” the fear of them provides.

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.

Co‐occurrence with humans presents substantial risks for large carnivores, yet human‐dominated landscapes are increasingly crucial to carnivore conservation as human land use continues to encroach on wildlife habitat. Flexibility in large carnivore behavior may be a primary factor mediating coexistence with people, allowing carnivores to calibrate their activity and habitat use to the perceived level of human risk. However, our understanding of how large carnivores adjust the timing and location of behaviors in response to variations in human activity across the landscape remains limited, impacting our ability to identify important habitat for populations outside of protected areas. Here we examine whether African lions ( Panthera leo ) modify their behavior and habitat use in response to risk of a human encounter, and whether behavior‐specific habitat selection allows lions to access feeding opportunities in a human‐dominated landscape in Kenya. We determined fine‐scale behavioral states for lions using high‐resolution GPS and accelerometer data, and then investigated behavior‐specific habitat selection at multiple temporal and spatial scales (ranging from 15 minutes to 12 hours and from approximately 200 meters to several kilometers). We found that lions exhibit substantial differences in habitat selection with respect to humans based on behavioral state and time of day. During the day, when risk of human encounter is highest, lions avoided areas of high human use when resting, meandering, and feeding. However, lions specifically selected for habitat near people when feeding at night. Flexible habitat use by lions thus permits access to prey, which appear to concentrate in areas near humans. The importance of habitat near people for feeding was only apparent when analyses explicitly accounted for lion behavioral state and spatiotemporal scale, highlighting the necessity of incorporating such information when investigating human impacts on large carnivore habitat use. Our results support the contention that behavior‐specific habitat selection promotes carnivore persistence in human‐dominated landscapes, demonstrating the importance of considering not just whether but how large carnivores use habitat near humans when managing vulnerable populations.