Kotrina Kajokaite: University of California, Los Angeles

Coalitionary recruitment offers a window into animal social cognition. However, naturally observed coalitionary conflicts are challenging to analyze because the researcher has no control over the context in which they occurred, and observed behavior patterns are typically consistent with multiple explanations. In this talk, I will present analyses of observational data of coalitionary solicitations during conflicts in wild capuchin monkeys, Cebus capucinus, collected at Lomas Barbudal Biological Reserve, Costa Rica. In this study we employed a statistical technique that models monkeys’ choices of allies during coalitionary conflicts while taking into account not only the attributes of the chosen individual, but also of the other individuals who were available to be solicited for help. This statistical technique also allows to simultaneously compare different hypotheses regarding which cues monkeys use and how these cues interact. Our analysis shows that capuchin monkeys use information about both relationship quality and dominance when recruiting allies during conflicts. Monkeys primarily use rank when recruiting an ally, but will also use relationship quality, particularly when the potential ally has low rank. This study provides evidence that nonhuman primates are able to classify other group members using multiple criteria simultaneously. In addition, this study presents a statistical technique that animal researchers can use to infer decision rules from observational data.