A research group led by Associate Professor Michio Nakamura of Kyoto University observed for the first time in the world a "confrontational scavenger" in which wild chimpanzees obtain leopard prey and eat it in the presence of leopards.It has been shown that the confrontational scavenger, which is important in human evolution, may be traced back to the human lineage.Other researchers from Kamakura Women's University, Research Institute for Humanity and Nature, Osaka Narumi University, Teikyo University of Science, Kansai Gakuin University, and Nagano College of Nursing participate in the research group.
When large carnivores such as lions and leopards kill their prey, early humans may "face" the carnivores to drive them away and steal their prey.There was no evidence that this "confrontational scavenger" was performed by chimpanzees, who are most closely related to humans.Therefore, confrontational scavenger is important for human cooperation and language evolution, and it has been said that it first appeared in the human lineage.
For the first time, the research group observed a chimpanzee getting and eating a corpse of prey in the Mahale Mountain National Park, Tanzania, with a leopard nearby.At this time, there was a leopard's fangs in the throat of the prey, a leopard was witnessed in the vicinity, and a chimpanzee was calling out.
Summarizing the cases of chimpanzees encountering animal carcasses (1980-2017), 49 of 18 cases (36.7%) were scavengers.Carcasses are often eaten when the carcasses are fresh and hunted and accustomed to eating. In this case, carcass scavenger was observed in 12 of 9 cases (75.0%).On the other hand, even if the leopard may return, it was found that scavenger may be eaten if these conditions are met.
The results of this research indicate that the confrontational scavenger may have appeared before the human lineage.Therefore, the scavenger hypothesis, which is becoming an established theory in the discussion of human evolution, needs to be reviewed in the future.
Paper information:[Journal of Human Evolution] Wild Chimpanzees Deprived a Leopard of Its Kill: Implications for the Origin of Hominin Confrontational Scavenging
