Take it or leave it: transport of tools for future use by long-tailed macaques (Macaca fascicularis)

Future planning has previously been considered unique to humans. However, certain animals can foresee some of their future needs. We tested long-tailed macaques (Macaca fascicularis) ability to transport and after a delay use a rake, in two experiments. Firstly, six rake tool-trained macaques failed to select and after a delay, transport the rake. Secondly, five of the macaques were shaped on transporting the rake for immediate rewards. Now, all of the macaques transported and used the rake after a delay of 5 min; one was successful after 10 min and even on a few trials after 20 min. The macaques failed to plan in the first experiment, potentially because they were unable to foresee the appropriate sequence of behaviours to solve the task. After shaping, they displayed flexibility by successfully transporting tools after delays. Remarkably, several macaques generalized this behaviour by attempting to use non-provided objects or their tails. Our results show which information and experience macaques need in order to display tool transport for future use.