Protracted development of stick tool use skills extends into adulthood in wild western chimpanzees
Fig 7
Age effect on the probability of using the levering action with a stick tool in larvae extraction and nut kernel extraction.
The regression lines obtained from the Bayesian regression model (nut kernel extraction = brown, larvae extraction = green) with a 95% credible interval are shown. Each circle (larvae extraction = green, nut kernel extraction = brown) represents the sum of occurrences of levering action performed per individual in the dataset. S1 Data and S1 Code contain the data and code to generate this figure.