Fission-Fusion Dynamics of Large Ateline Species

社会性的增强一直被认为是灵长类动物区别于其他哺乳动物的特征之一。大多数白天活动的灵长类动物生活在有凝聚力的社会群体中，在这些群体中，成员大部分时间都在很近的距离内活动。然而，长期实地研究的数据显示，灵长类社会群体的凝聚力随着时间的推移发生了更大的变化。我们现在认识到一种称为“裂变-融合动力学”的内聚谱，其中子群的形成和大小、组成和空间内聚的变化。我的研究计划的长期目标是通过对两种密切相关的灵长类物种的研究，揭示分裂融合社会变化的原因和后果，这两种物种在凝聚力水平上差异很大。蜘蛛猴和吼猴是体型庞大的新热带猿亚科的成员，它们经常生活在同一片森林中，但它们在生态和社会组织方面却表现出惊人的差异。嚎叫是一种以树叶为食的动物，它们一直生活在小而紧密结合的群体中（低裂变融合动力学），范围小，空间接近。蜘蛛猴是成熟的水果专家，它们生活在大的、高度流动的社区（高裂变融合动力学）中，有很大的家庭范围，在这些社区中，具有流动（经常变化）成员的亚群广泛分散。因此，在伯利兹的逃跑河自然保护区（RCNR）研究地点发现的蜘蛛和嚎叫动物都是研究灵长类动物社会性变异和裂变融合动力学的绝佳对象。该研究项目自1999年开始活跃。在接下来的五年里，我将研究：生态和亲缘关系如何决定裂变-聚变动力学的变化；性隔离、性选择与裂变聚变动力学之间的关系以及这种灵活的社会在压力和疾病方面的后果。本课程将全面介绍亲缘关系、生态学、性选择、压力和疾病如何塑造和限制哺乳动物的社会性。通过研究影响群体凝聚力和结社模式的环境和社会条件，我的目标是更好地理解哺乳动物社会性本身的进化。

Enhanced sociality has long been recognized as one of the traits distinguishing primates from other mammals. Most day-active primates live in cohesive social groups in which members range in close proximity most of the time. However, data emerging from long-term field studies are revealing much greater variation in cohesiveness in primate social groups over time. We now recognize a spectrum of cohesiveness, termed “fission-fusion dynamics”, in which subgroups form and change in size, composition, and spatial cohesion. The long-term objective of my research program is to uncover the causes and consequences of variation in fission-fusion sociality through the study of two closely related primate species that vary dramatically in their levels of cohesion. Spider and howler monkeys, members of the large bodied Neotropical subfamily Atelinae, are often found living in the same forests, yet they show striking contrasts in ecology and social organization. Howlers are leaf eaters that live in consistently small and tightly cohesive groups (low fission-fusion dynamics) with small ranges and close spatial proximity. Spider monkeys are ripe fruit specialists that live in large, highly fluid communities (high fission-fusion dynamics) with large home ranges over which subgroups with fluid (often changing) membership are widely dispersed. Spiders and howlers, both found at the Runaway Creek Nature Reserve (RCNR) study site in Belize, are thus excellent subjects for the study of variation in primate sociality and fission-fusion dynamics. This research program has been active since 1999. Over the next five years I will investigate: how ecology and relatedness determine variation in fission-fusion dynamics; the relationship between sexual segregation, sexual selection, and fission-fusion dynamics; and the consequences of such flexible sociality in terms of stress and disease. This program will provide a comprehensive account of the manner in which relatedness, ecology, sexual selection, stress, and disease shape and constrain mammalian sociality. By investigating the environmental and social conditions that affect group cohesiveness and association patterns, I aim to better understand the evolution of mammalian sociality itself.