Abstract：
Primate social organizations, or grouping patterns, vary significantly across species. Behavioral strategies that allow for flexibility in grouping patterns offer a means to reduce the costs of group living. Chimpanzees (Pan troglodytes) have a fission-fusion social system in which temporary subgroups (\"parties\") change in composition because of local socio-ecological conditions. Notably, western chimpanzees (P. t. verus) are described as showing a higher degree of bisexual bonding and association than eastern chimpanzees, and eastern female chimpanzees (P. t. schweinfurthii) are thought to be more solitary than western female chimpanzees. However, reported comparisons in sociality currently depend on a small number of study groups, particularly in western chimpanzees, and variation in methods. The inclusion of additional communities and direct comparison using the same methods are essential to assess whether reported subspecies differences in sociality hold in this behaviorally heterogeneous species. We explored whether sociality differs between two communities of chimpanzees using the same motion-triggered camera technology and definitions of social measures. We compare party size and composition (party type, sex ratio) between the western Gahtoy community in the Nimba Mountains (Guinea) and the eastern Waibira community in the Budongo Forest (Uganda). Once potential competition for resources such as food and mating opportunities were controlled for, subspecies did not substantially influence the number of individuals in a party. We found a higher sex-ratio, indicating more males in a party, in Waibira; this pattern was driven by a greater likelihood in Gahtoy to be in all-female parties. This finding is the opposite of what was expected for eastern chimpanzees, where female-only parties are predicted to be more common. Our results highlight the flexibility in chimpanzee sociality, and caution against subspecies level generalizations.
摘要：
灵长类社会组织，或分组模式，物种间差异很大。允许分组模式灵活性的行为策略提供了一种降低团体生活成本的方法。黑猩猩（Pantroglodytes）具有裂变融合社会系统，由于当地的社会生态条件，临时亚群（“政党”）的组成发生变化。值得注意的是,西方黑猩猩(P.t.verus）被描述为比东部黑猩猩表现出更高的两性结合和关联程度，和东部雌性黑猩猩(P.t。schweinfurthii）被认为比西方雌性黑猩猩更孤独。然而,报道的社会性比较目前取决于少数研究组，特别是在西方黑猩猩中，和方法的变化。纳入其他群落并使用相同方法进行直接比较对于评估所报告的社会性亚种差异是否适用于这种行为异质性物种至关重要。我们使用相同的运动触发相机技术和社会措施的定义，探讨了两个黑猩猩社区之间的社会性是否不同。我们比较派对规模和组成(派对类型，性别比例）在宁巴山脉（几内亚）的西部Gahtoy社区和Budongo森林（乌干达）的东部Waibira社区之间。一旦对食物和交配机会等资源的潜在竞争得到控制，亚种对聚会中的个体数量没有实质性影响。我们发现性别比例更高,表明派对上有更多的男性，在Waibira；这种模式是由Gahtoy更有可能参加全女性派对驱动的。这一发现与东部黑猩猩的预期相反，预计只有女性的派对会更常见。我们的结果突出了黑猩猩社会性的灵活性，并警惕亚种水平的概括。
