Female chimpanzees are making and wielding spears out in the wild, according to a new finding about the wild animals in Africa. This finding could also lead to a new understanding of the development of our own species.
Much of the general public — and some researchers — hold the traditional view that males among our ancestors made tools and hunted, while females stayed at home, taking care of children. This new study provides evidence that view could be far from the truth.
Iowa State University researchers reported in 2007 that chimpanzees near Fongoli in Senegal were using tools, including spears, to hunt. The team also noted in that initial study that females of the species were the ones crafting most of the weapons. However, the small sample size of that initial study led some scientists to question the conclusions of the research. Over the last eight years, investigators have documented more than 300 hunts utilizing spears and other instruments for hunting.
Males make up 60 percent of the chimpanzees in the study group, yet they undertook just 40 percent of the hunting expeditions. They also generally used their hands to capture and kill prey, while females were found to use tools quite often on the hunt.
"It's just another example of diversity in chimp behavior that we keep finding the longer we study wild chimps. It is more the exception than the rule that you'll find some sort of different behavior, even though we've studied chimps extensively," Jill Pruetz, an anthropology professor at Iowa State University, said.
Galagos, small nocturnal primates popularly known as bush babies, are a favorite food of the chimpanzees in the region. Often, female chimpanzees were observed poking at galagos hiding in trees. As the prey animals ran out from their cover, they were captured by male chimpanzees using their bare hands.
One question that puzzles scientists is why the chimps at Fongoli regularly use spears, while primates in other areas of the world do not. The answer may lie in the group's social structure, which allows these chimps to keep and eat anything they catch. In other regions, the alpha male is awarded all such catches. Galagos are also easy targets for female chimps using spears, compared with the red colobus monkeys hunted by other chimpanzees.
Fongoli chimps are the only nonhuman animal known to regularly employ tools in hunting vertebrates, potentially revealing secrets about the adoption of the practice by distant human ancestors.
Study of hunting roles played by male and female chimpanzees in Fongoli the region was published in the journal Royal Society Open Science.
Photo: William Warby | Flickr
