Arithmetic-Like Reasoning in Wild Vervet Monkeys: A Demonstration of Cost-Benefit Calculation in Foraging
Figure 4
“Foraging attempt” rates for one-step subtraction. The “foraging attempt rates” were expressed as the percentage of “attempt made” trials over the total number of trials in each condition for each subject. The number of sessions completed was 17 for Mkono and Mkia, and 12 for Mke. : , : , : . values are two tailed. Fisher’s exact test was conducted only once between the “2−1” and “2−2” conditions for testing differences among the three conditions: “2−0”, “2−1”, and “2−2” for Mkono, since the frequencies for the “2−0” and “2−1” conditions were identical. The difference between the “2−0” and “2−2” conditions becomes marginally significant when the threshold is set at 2.5% for multiple comparison for Mkia. The difference between the “2−0” and “2−1” conditions becomes marginally significant when the threshold is set at 2.5% for multiple comparison for Mke.
