Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland.
Inkawu Vervet Project, Mawana Game Reserve, KwaZulu Natal, South Africa.
Am J Primatol. 2021 Feb;83(2):e23232. doi: 10.1002/ajp.23232. Epub 2021 Jan 19.
Previous primate social network studies largely limited their focus to grooming and/or aggression networks, particularly among adult females. In addition, the consistency of individuals' network centrality across time and/or different networks has received little attention, despite this being critical for a global understanding of dynamic social structure. Here, we analyzed the grooming, aggression, and play social networks of a group of 26-28 wild vervet monkeys (Chlorocebus pygerythrus), including adults and juveniles, over two periods of 6 months. We collected data on grooming, play, and aggression using focal animal sampling with instantaneous recording and ad libitum sampling. We examined whether individuals' network centralities were consistent over the two periods and across networks, as well as the effect of age, sex, and dominance rank on three individual centrality metrics in each network and within each study period. We found that individuals were quite consistent in their network position from 1 year to the next despite changes in group composition. However, their network centralities were not correlated across networks, except for Strength and weighted Eigenvector centrality between grooming and aggression networks. We also found that in the aggression network, high-rankers showed the highest centrality in most network metrics (e.g., Degree, Strength, and Eigenvector centrality) and compared to males, females were most central in 2017 but not in 2018. In the grooming network, high-ranking females had the highest Eigenvector centrality, whereas in the play network, juvenile males had the highest Eigenvector centrality. Our findings corroborate previous findings on vervet monkeys. In addition, they show that individuals' network centralities may vary among networks and over time; thus highlighting the effect of sociodemographics and behaviors' functions on the group level dynamics of social behavior.
先前的灵长类动物社交网络研究主要集中在梳理和/或攻击网络上，特别是在成年雌性中。此外，尽管这对于全面了解动态社会结构至关重要，但个体在时间和/或不同网络中的网络中心性一致性却很少受到关注。在这里，我们分析了 26-28 只野生绿长尾猴（Chlorocebus pygerythrus）的梳理、攻击和玩耍社交网络，包括成年猴和幼猴，时间跨度为两个 6 个月。我们使用焦点动物采样，即时记录和任意采样，收集了梳理、玩耍和攻击的数据。我们研究了个体在两个时期和不同网络中的网络中心性是否一致，以及年龄、性别和支配地位对每个网络和每个研究期间三个个体中心性度量的影响。我们发现，尽管群体组成发生了变化，但个体在网络中的位置在 1 年内到下一年保持相对稳定。然而，它们的网络中心性在网络之间没有相关性，除了梳理和攻击网络之间的强度和加权特征向量中心性。我们还发现，在攻击网络中，高等级者在大多数网络度量（例如，度数、强度和特征向量中心性）中表现出最高的中心性，与雄性相比，雌性在 2017 年而不是在 2018 年最为中心。在梳理网络中，高等级雌性具有最高的特征向量中心性，而在玩耍网络中，幼猴雄性具有最高的特征向量中心性。我们的发现与先前关于绿长尾猴的研究结果一致。此外，它们表明个体的网络中心性可能在网络之间和随时间变化而变化；从而突出了社会人口统计学和行为功能对群体水平社会行为动态的影响。
