Death of the Alpha: Within-Community Lethal Violence Among Chimpanzees of the Mahale Mountains National Park
Chimpanzees (Pan troglodytes) are capable of extreme violence. They engage in inter-group, sometimes lethal, aggression that provides the winners with an opportunity to enlarge their territory, increase their food supply and, potentially, attract more mates. Lethal violence between adult males also occurs within groups but this is rare; to date, only four cases (three observed […]
Social instability raises the stakes during social grooming among wild male chimpanzees
Explaining cooperative behaviour is a fundamental issue for evolutionary biology. The challenge for any cooperative strategy is to minimize the risks of nonreciprocation (cheating) in interactions with immediate costs and delayed benefits. One of a variety of proposed strategies, the raise-the-stakes (RTS) strategy, posits that individuals establish cooperation by increasing investment across interactions from an […]