Research overview: nonconsumptive (risk) effects of felids on prey

A survey of how cats influence prey populations through fear and disturbance rather than direct killing. Risk effects include reduced foraging, heightened vigilance, altered habitat use, physiological stress and lowered reproduction, which together can depress prey numbers and behavior independent of consumption. This overview compiles evidence from felid systems, from pumas affecting deer to lions and tigers affecting ungulates, and discusses methods for partitioning consumptive from nonconsumptive effects, such as predator-cue experiments and comparisons across predation-risk gradients. It considers theoretical predictions that risk effects can equal or exceed lethal effects and the conditions, like ambush hunting and predictable risk, that amplify them. The topic is central to modern predator-prey ecology and to assessing the full impact of large cats.