ETD

• aggression
• Equus caballus
• proximity
• social dynamics
• social network analysis

Animal societies undergo constant change, which can perturb the social relationships among their members. These systems are complex, with affiliative bonds and hierarchical dynamics jointly contributing to group stability. This study examines two groups of horses (Equus caballus) grazing in the Tuscan-Emilian Apennine National Park were subject to different management regimes. One group (the unperturbed group) maintained a stable composition throughout the data-collection period, whereas the other (the perturbed group) experienced repeated and abrupt additionts and removals of individuals. Using social network analysis, we investigated how individual traits, such as sex, class of age, and aggression level, shaped social positions within the groups. Aggression index significantly influenced centrality measures in the unperturbed group, but not in the perturbed group. In both groups, certain centrality measures increased over time, reflecting natural fluctuations in association patterns driven by external factors. Finally, we characterized network structures and their temporal dynamics to better understand how management-induced perturbations affect social cohesion.