Prey tell, large herbivores fear the human ‘super predator’

Daniel A. Crawford and Michael Cherry, Caesar Kleberg Wildlife Research Institute, Texas A&M University - Kingsville, Kingsville, TX, Daniel A. Crawford and L. Mike Conner, Wildlife Research, The Jones Center at Ichauway, Newton, GA, Michael Clinchy and Liana Y. Zanette, Biology, University of Western Ontario, London, ON, Canada

Background/Question/Methods
Fear of the human ‘super predator’ has the potential to alter the feeding behaviour of large carnivores and result in human-induced trophic cascades. However, it has yet to be experimentally tested if large herbivores perceive humans as predators and exhibit behavioral responses strong enough to affect their demography. We conducted a predator playback experiment exposing white-tailed deer to locally extirpated and extant predator (coyote, cougar, dog, wolf, human) and non-predator control (bird) vocalizations at food patch sites to measure relative fear responses of deer to predators with respect to effects on deer feeding behavior.
Results/Conclusions
We found that deer were more than twice as likely to flee from humans than other predators and were matched only by wolves in reducing overall feeding time and return rates during the hour following human playbacks. Combined with previous, site-specific research linking deer fecundity to predator abundance, this study reveals that fear of humans has the potential to induce a larger effect on ungulate reproduction than has ever been reported. By demonstrating that deer fear humans more than other predators, present and past, our results support that fear of the human ‘super predator’ affects prey species and suggest potential for far-reaching effects on ungulate reproduction.