Communication and fission-fusion dynamics in white-nosed coatis

There are both costs and benefits to group living. Benefits include reduced predation risk, while costs involve increased competition among group members for resources. Some social groups manage these trade-offs through fission-fusion dynamics, where groups regularly split into subgroups (fission) and later merge back together (fusion). Understanding the factors that drive these events and the mechanisms group members use to navigate these processes can provide insights into the proximate and ultimate drivers of group living. In this thesis, I use white-nosed coatis as a study system to investigate the extent and nature of their fission-fusion dynamics and the role of vocal signalling during these processes. By leveraging advanced tracking technologies, I simultaneously recorded the locations and vocalisations of all members of three wild white-nosed coati groups in Soberania National Park and on Barro Colorado Island, Panama. Utilising these data, I characterise the extent of white-nosed coati fission-fusion dynamics and investigate the role of social and demographic factors in shaping their subgrouping behaviours. I found that individuals have consistent social preferences when deciding whom to split with, and these preferences are driven by relatedness rather than demographic factors such as age and sex. I characterise different fission and fusion types, providing a framework for investigating these processes that can be applied across diverse social and ecological contexts. I show that coatis use vocalisations to coordinate fission and fusion events and suggest that these events are driven by varying preferences for when to travel and foraging competition. These results offer new insights into the factors that shape decision-making processes, shedding light on the drivers of group living.