Abstract
Predation is one of the fundamental forces that shapes our natural world. The direct effect of predation can be broken down into consumptive and non-consumptive effects. Several predator-prey ecology studies have suggested that the magnitude of the impact of non-consumptive effects of predation (NCEs) on prey can match or surpass that of consumptive effects (CEs). Behavioral risk effects are anti-predatory behavioral strategies adopted by prey in response to predation risk that incur a cost and are one of the most common and widely studied NCEs. The aim of this study was to further our understanding of general predator-prey ecological knowledge in natural systems by examining the behaviors and behavioral decision making of great white sharks and Cape fur seals before, during and after predator-prey interactions under entirely natural conditions and by examining the potential impacts of anti-predatory mobbing behavior on predation frequency and success rates. The results of this study found a much lower predation success rate for sharks despite a similar predation frequency when compared to other white shark-fur seal predation hotspots. White sharks had significantly lower attack and kill probabilities when they were getting mobbed compared to when they were not getting mobbed by seals. Seals were also three times less likely to be attacked when they were in a mob group compared to engaging in other behaviors. Similarly, seal behavior preceding predatory versus non-predatory interactions significantly differed. Taken together, these results suggest complete observations of predator-prey interactions appear to be significantly influenced by individual prey behavior, though there are almost certainly additional unobservable factors that influence predator behavior and therefore predator-prey dynamics. Furthermore, anti-predatory mobbing behavior appears to have significant implications for predation frequency and success rates, though the incurred cost remains unknown.