New research reveals why chimpanzees attack humans

Scientists from Kyoto University, Japan, studying chimpanzees in Guinea have published research revealing why primates attack humans and what prevention measures can be taken. The study, published in a special issue of The American Journal of Primatology, suggests that while rare, attacks by primates on humans may increase as wild habitat is increasingly converted for agriculture.

The team were based in the village of Bossou in south-eastern Guinea, West Africa, where humans and chimpanzees coexist as the primates' 15km2 home range is fragmented by fields, farms roads and paths. Unlike most other places in Africa, local people at Bossou have strong religious beliefs concerning the chimpanzees that have resulted in their continued protection over the years. Chimpanzees in Bossou have been studied by the Kyoto University Research Team since 1976 and systematic data about attacks on humans by the apes has been collected since 1995; however it is believed that attacks occurred at Bossou before the researchers' presence

Unlike most other places in Africa, local people at Bossou have strong religious beliefs concerning the chimpanzees that have resulted in their continued protection over the years.

Chimpanzees in Bossou have been studied by the Kyoto University Research Team since 1976 and systematic data about attacks on humans by the nonhuman apes have been collected since 1995; however attacks it is believed occurred at Bossou before the researchers' presence.

The team investigated eleven attacks, carrying out victim interviews and found that although the families of attack victims felt angry and fearful toward chimpanzees after attacks, some drew on their traditional beliefs to explain why chimpanzees were respected, protected, and could not hurt them, even when attacks occurred.

Furthermore attacks occurred during periods that coincided with a lack of wild foods, increased levels of crop-raiding, and periods of human cultivation.

The team concluded that the conservation of primate habitat is crucial to preventing resource based attacks on humans by primates. They also considered measures which could be taken by the villagers, including the removal of specific fruit trees which may attract the chimpanzees, or keeping any transported food out of sight.

"In general people should keep calm, try not to scream and avoid running off or scattering, especially within groups," said Dr Kimberley Hockings from the New University of Lisbon in Portugal, a co-guest editor of the special issue. "In the village we recommended that children should not be left alone near forest boundaries."

This research is published as part of a special issue on ethnoprimatology, a discipline which seeks to understand the relationship between humans and primates from ecological, social and cultural perspectives.

"The relationship between humans and nonhuman primates worldwide is complex. Wild animals attack hundreds of people globally every year and while most nonhuman primates are fearful of humans certain species such as chimpanzees and baboons have a higher tendency to attack," said Dr Hockings. "Humans have long exploited nonhuman primates, our closest living relatives, for food, traditional medicine and even as pets. Yet in some societies nonhuman primates are revered as godlike creatures. In Bossou the villagers considered the chimpanzees a sacred totem animal."

The research on nonhuman primate attacks is an example of how human ecology and behaviour can influence, and be influenced by, the ecology and behaviour of primates. For villages bordering primate territory crop raiding and fear of attack by primates can affect the livelihoods of humans.

On the other hand human alteration of the landscape for farming, hunting, religious beliefs, and even pet keeping can affect the behaviour and ecology of primates.

"We believe that human-nonhuman primate interaction is going to be among the most important areas of primatological research in the 21st century," concluded Hockings. "Across Asia, America and Africa we cannot ignore that humans and other primates are increasingly coming into contact, competition and conflict. For example increases in forest clearing result in a decrease in nonhuman primate habitat, meaning a spatial and ecological overlap between human and our nearest relatives. We believe ethnoprimatology provides us with a tool to understand these interactions."