Social integration in temporal multiplex association networks predicts offspring survival in female Geoffroy's spider monkeys (Ateles geoffroyi)

While sociality is considered an important factor influencing female reproductive success, it is unclear how temporal social dynamics relate to it. We address this by evaluating the influence of social integration and its stability over time on offspring production and survival in Geoffroys spider monkeys (Ateles geoffroyi). Using 52,670 subgroup scan samples collected between 1997 and 2020, we compiled yearly association matrices among the sexually mature individuals of a wild group of spider monkeys, based on spatio-temporal co-occurrence in subgroups. We built Bayesian edge-weight models with the association matrices and generated 1000 samples of each yearly network, which we then used as layers in temporal multiplex networks. For each female with adult tenure [≥] 5 years (n= 17), we estimated strength and eigenvector versatility in the multiplex network that comprised the last 5 years of her tenure. We also estimated six (monolayer) centrality-based metrics in the yearly networks of females with adult-tenure [≥] 1 year and at least one recorded offspring born in the group (n=22). We tested the influence of these eight indicators of social integration as predictors of offspring production and survival. Results showed overall positive relationships between social integration and offspring survival, but not offspring production. The former could be due to better access to food resources or protection from within-group aggression. Our temporal multilayer approach contributed to the body of evidence regarding the fitness benefits of sociality. Significance StatementDespite the growing evidence of the influence of sociality on female fitness, there is limited information on how temporal variation in social dynamics relates to female reproductive success. We used long-term data on spatio-temporal co-occurrence in subgroups of spider monkeys to estimate network centrality metrics. We found that females with higher and more stable social integration had higher offspring survival, particularly for female offspring who reached age 5 (the onset of sexual maturity). Our study offers insights into the relationship between association and offspring survival in species with a high degree of fission-fusion dynamics and female dispersal.