Figure 3
Species differences in the effect of seasonal familiarity with the foraging area on (A) travel linearity and (B) travel speed. (A) The Mbendjele increased linearity as familiarity with the area increased (Estimate = 0.130, Std. Error = 0.066, z value = 1.960, P = 0.050), whereas Taï chimpanzees decreased linearity (Estimate = −0.174, Std. Error = 0.036, z value = −4.816, P < 0.001). (B) The Mbendjele’s off-trail travel speed was unaffected by familiarity with the foraging area (Estimate = −0.008, Std. Error = 0.016, t value = −0.501, P = 0.616), whereas Taï chimpanzees decreased travel speed as familiarity increased (Estimate = −0.053, Std. Error = 0.010, t value = −5.454, P < 0.001). The dashed lines represent the fitted model (with all other predictors being centered); dots represent (A) the averaged linearity and (B) the averaged speed per binned familiarity (29 bins with equal widths in log-transformed familiarity), and their area corresponds to the number of travel bouts in the respective bin (N = 1 to 53 per bin). Shaded areas represent 95% confidence intervals of the fitted model.
