Give Bonobos a lever long enough, and they will... lift a large stone out of the way so they can reach food. When researchers gave these apes a tray of tools and problems that require them, the bonobos easily used -- and modified! -- the tools.
Bonobos have never, to our knowledge, used tools in the wild-- and previously, only one captive bonobo named Kanzi used a stone tool. But in this study, 15 bonobos in a zoo and a sanctuary were tested and 6 succesfully used the tools (some almost immediately!). Sticks, rocks, and antlers served as digging tools, while the bonobos also used sticks as levers to move large rocks. The interesting thing, these researchers note, is that the bonobos appear to use tools in a manner similar to what our stone-age ancestors did. One bonobo even sharpened a stick with her teeth to make a spear! Thus, this may give us some insight into how tool use developed in humans.
On that note, the other important-- and obvious-- conclusion is that tool use clearly is a skill that can lie latent then awaken to its full potential if the situation arises. The fact that we observe this with bonobos, our close relatives, suggests that it may mimic the pattern of tool use development in our own human ancestors.
As for those in captivity, Itai Roffman of Haifa University in Israel and his colleagues previously observed one captive bonobo, called Kanzi, using stone tools to crack open a log and extract food. However, it was possible that Kanzi was a lone genius, raised by humans and taught sign language, as well as once being shown how to use tools. To find out if other captive bonobos shared Kanzi's aptitude, Roffman's team looked to animals at a zoo in Germany and a bonobo sanctuary in Iowa. The team gave them a series of problems that required tools to solve – for example, showing the bonobos that food was buried under rocks, then leaving a tray of potential aids such as sticks and antlers nearby.