Figure 4.

Transporting and saving raw food. (a) Percentage of trials where chimpanzees placed raw food in the cooking device when it was adjacent to them in the near condition, compared with when they had to transport it in the far condition (experiment 8). (b) Number of trials where chimpanzees saved their food in anticipation of future opportunity to place it in the cooking device (anticipation condition) compared with a control condition without such opportunities (experiment 9). Error bars indicate s.e.