Female chimpanzees may be the handy ones in the primate world, new research suggests.

Savanna chimps were observed using tools to hunt back in 2007, and a more recent study made the fascinating discovery that these innovative monkeys were predominantly female, Iowa State University reported.  Adult male chimpanzees tend to be the main hunters of social groups, but an observation of over 300 tool-assisted hunts in the Fongoli, Senegal population revealed over half were by females.

"It's just another example of diversity in chimp behavior that we keep finding the longer we study wild chimps," said Jill Pruetz, who first reported the Fongoli phenomenon. "It is more the exception than the rule that you'll find some sort of different behavior, even though we've studied chimps extensively."

The chimps were observed to use spear-like tools to jab at bush babies hiding in tree cavities, causing them to flee. One explanation for the gender roles is that male chimps tend to be more opportunistic.

"What would often happen is the male would be in the vicinity of another chimp hunting with a tool, often a female, and the bush baby was able to escape the female and the male grabbed the bush baby as it fled," Pruetz said.

The Fongoli chimp population are the only non-human animals to consistently hunt with tools. This may be because of a social tolerance unique to the chimp site.

"At Fongoli, when a female or low-ranking male captures something, they're allowed to keep it and eat it. At other sites, the alpha male or other dominant male will come along and take the prey. So there's little benefit of hunting for females, if another chimp is just going to take their prey item," Pruetz said.

The environment could also be contributing to the unique trait; the dry conditions of Fongoli make bush babies the most prevalent prey, and their hiding habits are more suited to tool use.

The findings were published in a recent edition of the journal Royal Society Open Science.