Life in a multi-predator environment : some considerations for anti-predatory vigilance

Abstract

Animals live in environments with many types of predators, yet studies of animal behavior under the risk of predation focus almost exclusively on environments. This is especially true in an important area of study: anti-predatory vigilance. A simple exploration of vigilance shows that several single-predator expectations may not apply in a environment. Two cases of vigilance are identified: predator-specific vigilance, in which the detection of a given predator requires a particular mode of vigilance, and non-specific vigilance, in which one mode of vigilance suffices for all predators. In both cases, and contrary to the situation, vigilance in a environment may respond little or even negatively to increasing attack rates. Furthermore, predator-specific vigilance may be directed exclusively towards the most abundant predator in the environment; the ignored predators are nonetheless important determinants of vigilance. Finally, most studies usually focus on the most dangerous predator faced by the animal in question, but in doing so ignore the role of additional, seemingly innocuous predators as important determinants of vigilance. Studies adopting a multi-predator perspective promise to shed much light on the study of anti-predator behavior in general.