Female Social Connectivity through the Leadership and Movement Progression of Tibetan Macaques at Mt. Huangshan, China

The present study investigates the leadership and progression of collective movements of Tibetan macaques (Macaca thibetana) found in Mt. Huangshan, China. I gathered information on their movements and social networks through all-occurrence, focal and scan sampling. I hypothesize that high-ranking females lead more collective movements than males as they have highly structured social bonds. I also predict that movements weighted by female presence are more efficient as societies are matrilineally structured and females are more socially connected. There were a total of 128 successful collective movements recorded over a 2-month period. There was no significant effect of sex, age or rank on the leadership frequency. The highest-ranking female (YH) and a young female (TXX) led more collective movements than expected by chance, which may be a consequence of the mating season. There was a significant difference in successful movement time between movements weighted by female presence and those unweighted, which may be due to the matrilineally-structured societies and strong female bonds present

Leadership in the Collective Movements of Tibetan Macaques (Macaca thibetana) at Mt. Huangshan, China

As a socially well-connected and cohesive species, humans tend to make many collective decisions. How do nonhuman species collectively relay information? We present data on the leadership of collective movements in Tibetan macaques (Macaca thibetana) in Mt. Huangshan, China, by analyzing their movements in relation to their social networks. All-occurrence sampling was used to investigate collective movement patterns, and focal and scan sampling were used to retrieve information on their affiliative and agonistic behaviors for a complete social network analysis. There were a total of 128 successful collective movements recorded over a two month period. All 20 adult individuals participated in collective movement leadership. There was no significant effect of sex, age, or rank on the leadership frequency of adult troop members. However, the highest-ranking female (YH) and a young female (TXX) significantly led more collective movements than expected by chance. The strength and eigenvector centrality of affiliative and agonistic social networks were significantly correlated with collective movement. Both females belong to different clusters in the social network analysis of collective movement, meaning that certain individuals tend to move with one female or the other. Individuals belonging to these two clusters may be a consequence of the mating season. An alpha level of .05 was used for all statistical tests. Supported by NSFC (30970414 & 31172106) and NSF-OISE (1065589)

Social connectivity among female Tibetan macaques (Macaca thibetana) increases the speed of collective movements

Social network analysis provides insights into patterns of group movements in primates, but fewer studies to date have focused on the dynamics of how such movements occur. In this study, we proposed and tested two hypotheses about the influence of sex on social connectivity and group movement in Tibetan macaques (Macaca thibetana): (1) adult females are socially more connected than are adult males and (2) social connectivity facilitates the speed of collective decision-making. We collected data from 128 successful collective movements (≥ 2 individuals followed an initiator within 5 min) over a 2-month period in a group of adult Tibetan macaques at Mt. Huangshan, China. Although high-ranking individuals of both sexes in our dataset were more central in their social network than were low-ranking individuals, our results show that affiliations between females were stronger, with more preferred associations than those between males. Groups with more females reached collective decisions faster than groups with fewer females. We conclude that female Tibetan macaques use their social networks to enhance the speed of collective decision-making, which may have associated fitness benefits