The Aggressive Apes? Causes and Contexts of Great Ape Attacks on Local Persons

Abstract

Attacks on humans by wildlife are a leading cause of ‘human–wildlife conflict’ and are on the rise due to increasing human populations and competition over space and resources. Thus far, little attention has focused on attacks by wild great apes on humans compared to other large mammals. This chapter reviews the complexities of human–great ape interactions, and examines the context and causes of ape attacks, including assessment of species differences in propensity to direct aggression towards humans. Physical attacks on people by wild great apes in Africa and Asia are overall rare. Most reports involve chimpanzees and, to a lesser extent, gorillas; wild orangutans and bonobos seem to rarely attack humans. Reports suggest that most gorilla attacks target adult humans and are motivated by defensive instincts (e.g. in response to hunting threat). In contrast, victims of wild chimpanzee attacks are overwhelmingly children, and attacks fall more evenly into provoked (i.e. in response to harassment) and unprovoked categories (e.g. predation on young children). Among great apes, the increased propensity of chimpanzees to attack humans is likely due to a combination of greater ecological flexibility that enables them to exploit disturbed habitats near people, their multimale social systems, tendencies for aggressive behaviours in day-to-day life, and more prevalent hunting behaviour. We discuss how improved knowledge of the contexts of ape attacks, along with a better understanding of human cultural attitudes and causes of conflict among different human stakeholder groups, are required to develop effective mitigation strategies to reduce likelihood of attacks.