Strategic third-party interventions in feral ungulate affiliation

Third-party interventions in agonistic behaviour play a key role in the maintenance of social relationships, but very little is known about how interventions in affiliation affect the distribution of sociality within a group. Social context affects behaviour investment and partner choice, with audience effects, bystander dynamics and interventions allowing animals to strategically manipulate the behaviour of others and protect their own social bonds by impeding bonding attempts. We examined the relationships between ongoing allogrooming and bystanders in feral cattle (<i>Bos taurus</i>), an overlooked system for studying social behaviours. We assessed the effect of bystander number and social relationships (both hierarchical and affiliative) on allogrooming duration and intervention likelihood. Feral cattle regularly intervened in each other's bonding attempts, and bystanders were more likely to intervene in allogrooming if they had a strong social bond with the performer but not the receiver, emphasizing that cattle monitor and selectively intervene in third-party interactions. Allogrooming duration increased with bystander number, suggesting that cattle potentially advertise relationships and status to peers. These results provide new insights into the importance of triadic awareness when measuring affiliative behaviour, indicating the potential adaptive role of intervention behaviour in maintaining social relationships and as a driver of social strategies.