Complex dynamics of social learning in groups of wild Arabian babblers.

Abstract

We studied the effect of a demonstrator on the learning of a novel foraging task in 12 groups of free-living cooperative breeding Arabian babblers (Argya squamiceps). We allowed naïve babblers to forage jointly on a foraging grid with a demonstrator previously trained to solve a task in one of 2 possible methods: lifting covers of 1 color or pecking through covers of another color. We found that most group members learned to solve the task using one of the methods, and persisted with it even when later tested with covers of a third (neutral) color that could be opened by both lifting and pecking. However, the method learned by group members did not necessarily follow the method used by the pre-trained demonstrator. Instead, learners within each group tended to use the same method (significantly more than expected by chance), and the extent to which groups differed from the demonstrator was correlated with the extent to which the demonstrator occasionally (and quite rarely) exhibited also the alternative method. These results, together with further analysis of the sequence of events in each group, suggest that both naïve birds and demonstrators learn socially from each other, as well as through individual trial-and-error learning, which enables naïve individuals to become demonstrators themselves and influence the pattern of social transmission. This process mostly leads to a homogenous group behavior, but one that cannot be predicted by the seeded demonstration.