Ecological and social determinants of association and proximity patterns in the fission–fusion society of spider monkeys (Ateles geoffroyi)

• Published in: American journal of primatology Vol. 82; no. 1; pp. e23077 - n/a
• Main Authors: Aguilar‐Melo, Adriana R., Calmé, Sophie, Pinacho‐Guendulain, Braulio, Smith‐Aguilar, Sandra E., Ramos‐Fernández, Gabriel
• Format: Journal Article
• Language: English
• Published: United States Wiley Subscription Services, Inc 01.01.2020
• Subjects: Animal behavior; Associations; Ateles geoffroyi; Availability; Change agents; Ecology; Fission; Food; Food availability; Fruit; fruit availability; Fruits; Monkeys; Primates; Proximity; Sampling; seasonality; Segregation; Sex; sexual segregation; Social factors; social network; Social network analysis; Social networks; Social organization; Species; Subgroups; Tropical forests; Variation; social network; fruit availability; sexual segregation; seasonality
• ISSN: 0275-2565; 1098-2345
• DOI: 10.1002/ajp.23077

Some social species exhibit high levels of fission–fusion dynamics (FFD) that improve foraging efficiency. In this study, we shed light on the way that FFD allows animal groups to cope with fluctuations in fruit availability. We explore the relative contribution of fruit availability and social factors like sex in determining association and proximity patterns in spider monkeys. We tested the influence of fruit availability and social factors on the association and proximity patterns using three‐year data from a group of spider monkeys in the Yucatan Peninsula of Mexico. We identified subgroup members and estimated their Interindividual distances through instantaneous scan sampling. We evaluated fruit availability by monitoring the phenology of the 10 most important food tree species for spider monkeys in the study site. Social network analyses allowed us to evaluate association and proximity patterns in subgroups. We showed that association patterns vary between seasons, respond to changes in fruit availability, and are influenced by the sex of individuals, likely reflecting biological and behavioral differences between sexes and the interplay between ecological and social factors. In contrast, proximity patterns were minimally affected by changes in fruit availability, suggesting that social factors are more important than food availability in determining cohesion within subgroups. Research Highlights Our study site is a seasonal tropical forest where changes in fruit availability influence the social organization of Ateles geoffroyi, a highly frugivorous species with high fission–fusion dynamics and sexual segregation. Association patterns varied according to food availability and the sex of individuals, reflecting the interplay between ecological and social factors as determinants of fission–fusion dynamics. Proximity patterns were minimally affected by changes in fruit availability, suggesting that social factors are more important at short Interindividual distances.