Y: What do you carry in your car trunk, Don, just in case you need it?
D: I keep a spare tire in there, jumper cables, a flashlight, and a jack.
Y: That shows that you plan ahead. Contrary to previous thought, it looks like humans aren't the only animals able to do this. Bonobos, our closest great ape relative, and orangutans, our most distant great ape relative, also appear to be capable of planning ahead.
D: In case of a flat?
Y: No, Mr. Wise Guy, but they can select an appropriate tool and save it for later use. The animals were taught how to use a tool to retrieve grapes from a machine. Then they were allowed access to a variety of tools, but no access to the fruit machine. Next they were transferred into another room for anywhere from an hour to fourteen hours. When brought back into the room with the fruit machine and allowed access to it, if they brought the correct tool, they could retrieve some grapes. Both bonobos and orangutans were better at this than chance would predict.
D: Haven't a lot of animals proven able to learn to use tools to retrieve food?
Y: Yes, but until now, animals have not been shown to save tools for later hunger. What's more, in this set of experiments, some animals were also successful in saving a tool for later retrieving a bottle of juice. The idea was that juice doesn't satisfy hunger like actual fruit does, and so this test would help to ensure that the animals weren't simply carrying around the right tool because they were hungry.
D: What's next? Can primates write poetry too?
Y: Time will tell, I guess.