Multiple motivations: Agonistic coalitions and interventions in blue monkeys (Cercopithecus mitis stuhlmanni)

Primates are known for forming agonistic coalitions, but most data come from species in which agonism occurs frequently and rank predicts fitness. We analyzed coalitions and interventions in wild blue monkeys (Cercopithecus mitis), in which both agonism and third-party involvement are rare, and in which rank does not predict fitness. Data came from a long-term study in the Kakamega Forest, western Kenya, spanning 12 years and 12 groups. These data revealed that intervening animals both supported winners and defended losers, and that coalition partners nearly always prevailed over their opponent. Adult females were joiners (intervening in the initial agonism) and juveniles were coalition-recipients disproportionately, while opponents were disproportionately adults, especially males. Joiners were most likely to support the original contestant who was winning (vs. unclear outcome or losing), but also favored the smaller of the original contestants (vs. same-sized or larger) and the one to ..., The study population of blue monkeys (Cercopithecus mitis stuhlmanni) inhabited the Kakamega Forest, western Kenya. During the study period (June  2006 - December 2018), a team of trained observers monitored multiple monkey groups on a near daily basis, moving around the group to conduct a daily census of its members, and conducting focal animal follows of adult females in a systematic way. They noted agonism whenever it occurred, which could be both ad libitum and as part of the focal animal follows carried out on all adult females; they also noted all coalitions and interventions. From these field records, we compiled a list of coalitions and interventions, which both involve one animal aiding another in an agonistic context. We distinguished interventions as a type of coalition in which observers witnessed one animal intervening in an initially dyadic dispute, in contrast to other “in progress” coalitions in which two individuals might be simultaneously threatening a third when first..., , # Data from: Multiple Motivations: Agonistic Coalitions and Interventions in Blue Monkeys (*Cercopithecus mitis stuhlmanni*)

[https://doi.org/10.5061/dryad.fxpnvx11q](https://doi.org/10.5061/dryad.fxpnvx11q)

## Description of the data and file structure

In social animals, cooperation can take the form of agonistic support, when two or more group-mates join forces in an aggressive interaction against a third party. While these coalitions are often successful, intervening in a dispute requires energy and likely increases the risk of injury relative to standing by. We therefore expect animals to intervene in agonistic conflicts strategically, minimizing their risks and costs and maximizing their benefits. This data set allows one to examine predictions from this hypothesis from a naturally living population of monkeys, focusing on the choice of which contestant to support when a ‘joiner’ intervenes in their dispute. The data set also allows one to compute descriptive statistics about th...