Mechanisms driving social structure in Octodon degus

We report results of a study on the mechanisms shaping social network structure in Octodon degus, a diurnal, semi-fossorial rodent endemic to Chile. Using data collected over three seasons (2022–2023), we tested the roles of nighttime spatial proximity, female social cohesion, and female homophily based on masculinization (anogenital distance) in shaping social associations. Nighttime spatial proximity was negatively associated with association strength, indicating that individuals that were closer at night exhibited stronger associations. Female social cohesion emerged as a driver of social structure, with stronger within-group associations observed in most seasons. However, female homophily based on anogenital distance did not influence social network structure, suggesting that its role may differ across populations depending on ecological and social conditions. Our findings highlight the importance of spatial and social factors in shaping degu social networks and emphasize the need for population-specific approaches when evaluating the influence of mechanisms on social structure.