Leadership linked to group composition in Highland cattle (Bos taurus): Implications for livestock management

Animals kept for livestock or conservation form strong cohesive groups when foraging and moving, in the same way as their wild counterparts. Collective decision-making involves making compromises by consensus to maintain group cohesion and synchronisation. This type of consensus can be observed during collective movements, when a leadership can emerge. In a distributed leadership, many group members may initiate collective movements but some individuals initiate more frequently than others and are more frequently followed by their conspecifics due to socio-demographic factors such as age, sex or dominance. In this study, we focused on organisation and leadership in the collective movements of semi-wild groups of Highland cattle (Bos Taurus). Highland cattle being often used in eco-pasture, studying leadership emergence and the use of space by animals may improve livestock and pastureland management. We studied nine different compositions (i.e., same location but with transfers of individuals) of four groups over a six-month period. The group sizes ranged from nine to 21 individuals. Results revealed that leadership is widely distributed in Highland cattle groups, with some individuals initiating more often than other group members. Indeed, in large groups, some group members never initiated movements. The number of followers within a movement was particularly influenced by the age of the initiator, its social centrality and dominance, but was also affected by the increase of pre-departure activities. This study also shows the influence of several variables on the joining rank of individuals during movement progression, such as age and social centrality. Finally, social centrality and the number of followers explained the departure latency between two individuals. Here, we proposed how these findings can help manage livestock.