An Orangutan Hangs Up a Tool for Future Use

Observational reports suggest that great apes perform tool-orientated actions in preparation for a tool's future use. Some of these observations suggest remarkable planning skills because the target for the tool's intended use was not present during the tool-orientated actions. Although these observational reports are intriguing, such planning ability has yet to be studied experimentally. To address this issue, I conducted two experiments that were inspired by an orangutan's innovative behaviour during a novel enrichment task: the orangutan spontaneously secured a tool he was using to rake-in rewards by hanging it up when it was not in use but would be required a short time later. Experiment 1 showed that securing the tool predominately occurred when the orangutan could anticipate the tool's future use, but rarely occurred when he could anticipate no further use for it. Experiment 2 indicated that the tool's atypical size and/or weight were possible factors that prompted the orangutan to hang up the tool. Overall, the findings suggest that an orangutan not only innovated a novel way of securing a tool, but did so in anticipation of its future use.