Figure 4
Species difference in the effect of foraging group size on travel linearity. The Mbendjele increased linearity when travelling in a larger foraging group (Estimate = 0.156, Std. Error = 0.071, z value = 2.195, P = 0.028), whereas Taï chimpanzees decreased linearity when travelling in a larger group (Estimate = −0.140, Std. Error = 0.071, z value = −1.969, P = 0.049). The dashed lines represent the fitted model (with all other predictors being centered); dots represent the averaged linearity per binned group size (29 bins with equal widths in log-transformed group size), and their area corresponds to the relative number of travel bouts in the respective bin (N = 1 to 184 per bin). Shaded areas represent 95% confidence intervals of the fitted model.
