Elisa Bandini, T. Revathe, Elliot Howard-Spink, Caroline Schuppli

Many species exhibit the capacity for social learning. However, the importance of social learning for wild individuals’ daily lives and its role in the emergence of animal culture remains to be uncovered. As observing conspecifics may provide a relatively safe and efficient means of learning, visual species may use observational learning to acquire various types of information from others. However, identifying precisely when social observation leads to information transmission can be challenging. A behaviour known as “peering” (i.e., “close-range and sustained observation of the activities of conspecifics”) is being studied increasingly frequently across primate species in the wild as a potential indicator of social learning. Growing individual-level observational datasets of peering behaviour and its contexts present unique opportunities to study if and how peering leads to learning. However, to determine whether peering leads to observational social learning, researchers must systematically and carefully validate whether peering events facilitate information transmission between individuals, and do not solely serve social functions unrelated to learning. In this piece, we outline key predictions and limitations associated with identifying learning through peering, and provide concrete recommendations for the collection and analysis of data to evaluate our predictions. Despite focusing primarily on primates, our predictions and recommendations can be applied to any visual species that acquires parts of their cultural repertoire via observational social learning.

Elliot Howard-Spink, Monika Mircheva, Judith Burkart & Simon Townsend

Many animals communicate using sequences of signals, but identifying recurrent, non-random signal combinations remains methodologically challenging. Collocation analyses are increasingly popular approaches for detecting which signals animals combine at rates greater than expected by chance. However, existing methods for animal collocation analysis face several limitations that reduce their statistical rigour: they lack uncertainty estimates, fail to control for non-independence in sampled data, and do not account for inflated family-wise error rates when identifying attraction among many different signal types. These limitations restrict the broader applicability of animal collocation analysis, including preventing robust comparisons of signal combination strength between cohorts (e.g. populations, sexes or age classes). We adapt a novel form of Multiple Distinctive Collocation Analysis using Pearson residuals (MDCA-Pr) that addresses these statistical limitations, and validate its use in animal communication research in three ways: first, using numerous simulated datasets of different sizes and levels of signal recombination; second, using simulated data to evaluate the performance of MDCA-Pr in intercohort comparisons, and third, by demonstrating how MDCA-Pr can be applied to compare the vocal sequences produced by male and female captive-living common marmosets (Callithrix jacchus). MDCA-Pr shows high sensitivity, including at small sample sizes, and generally low false-positive rates, which we further reduce by applying additional criteria for identifying attraction between signals. During intercohort comparisons, MDCA-Pr is conservative, with low false-positive rates, and statistical power increases with sample size. MDCA-Pr is a robust method for evaluating signal attraction in animal communication and enables accurate intercohort comparison of animal signal combinations.