Individual-level movement bias leads to the formation of higher-order social structure in a mobile group of baboons

In mobile social groups, influence patterns driving group movement can vary between democratic and despotic. The arrival at any single pattern of influence is thought to be underpinned by environmental factors and group composition. To determine the specific patterns of influence in a chacma baboon troop we used spatially explicit data to identify patterns of individual movement bias on travel decision-making. We scaled these estimates of individual-level bias to the group as a whole by constructing an influence network, and assess its emergent structural properties. Our results suggest that individual animals respond consistently to specific group members, and that higher-ranking animals are more likely to influence the movement of others. At the group level, we identified a network structure with a single core and two outer shells. The presence of a core in this troop suggests that a set of highly inter-dependent individuals drive routine group movements. Our findings suggest that heterogeneity in individual level movement bias can lead to group level influence structures, and that movement patterns in mobile social groups can add to the exploration of both how social influence patterns develop (i.e., mechanistic aspects) and their linkages to individual and group level outcomes (i.e., functional aspects).