Doctoral Dissertation Improvement: The ontogeny of male-male bonds in wild Ethiopian geladas (Theropithecus gelada)

虽然雄性-雄性债券在雄性-philopatric灵长类动物中相对常见，但在雄性分散的物种中这些债券的证据很少。 尽管有文献表明，在这种情况下，男性与男性之间的联系会产生生殖后果，但人们对这些联系是如何发展的知之甚少。博士生Caitlin Barale（普林斯顿大学）在丹尼尔·鲁宾斯坦博士的指导下，研究了狮尾狒狒（Theropithecus gelada）雄性-雄性关系的个体发育，这是一个以雄性扩散和雄性-雄性关系为特征的物种。本研究的主要目的是研究雄性债券的性质，并确定的行为和激素因素，设置少年狮尾狒狒男性的个人生殖轨迹，因为他们从纳塔尔的一个男性单位过渡到一个临时的同龄人群体，并向前进入一个全男性单身汉组。该项目有四个具体目标：（1）描述青少年同伴群体，（2）描述青少年时期的男性-男性关系，（3）评估这些关系的短期效益，（4）调查男性关系在肾上腺素初显时如何变化。研究人员采用了横截面和纵向行为分析，社会网络分析和非侵入性粪便激素采样的所有少年男性（N=51）在西米恩山脉国家公园，Ethiopia.This研究代表了第一个长期的研究专门集中在少年狮尾。它提供了一个有价值的新视角，通过收集的行为，生理和网络为基础的数据，并启动了第一个纵向数据集已知的狮尾狒狒男性的社会发展。拥有已知个体从幼年到成年的详细数据，使研究人员能够将早期生命的影响与终身生殖成功联系起来。这项研究的结果将为灵长类动物中雄性-雄性关系的发展提供新的数据，推进社会网络理论在动物系统中的应用，并帮助建立早期人类，现代人类和其他非人类灵长类动物的社会发展模型。

Although male-male bonds are relatively common in male-philopatric primates, evidence for these bonds in species with male dispersal is rare. Despite documentation that male-male bonds have reproductive consequences in this context, little is known about how these bonds develop. Doctoral student Caitlin Barale (Princeton University), under the supervision of Dr. Daniel Rubenstein, investigates the ontogeny of male-male relationships in the gelada (Theropithecus gelada), a species characterized by both male dispersal and male-male bonds. The primary objective of this research is to examine the nature of male-male bonds, and identify the behavioral and hormonal factors that set juvenile gelada males on individual reproductive trajectories as they transition from their natal one-male unit, to a temporary peer group, and onwards into an all-male bachelor group. The project has four specific goals: (1) to describe juvenile peer groups, (2) to characterize male-male bonds in the juvenile period, (3) to evaluate a short-term benefit of these bonds, and (4) to investigate how male relationships change at adrenarche. The investigators employ a combination of cross-sectional and longitudinal behavioral analyses, social network analysis and non-invasive fecal hormone sampling on all juvenile males (N=51) in a band of geladas in the Simien Mountains National Park, Ethiopia.This research represents the first long-term study focused exclusively on juvenile geladas. It provides a valuable new perspective on gelada social development through the collection of behavioral, physiological and network-based data, and initiates the first longitudinal dataset on known gelada males. Having detailed data on known individuals from juvenility to adulthood allows researchers to connect the effects of early life to lifetime reproductive success. The results of this research will contribute novel data on the development of male-male bonds in primates, advance the application of social network theory to animal systems, and help build a model for social development in early hominins, modern-day humans, and other non-human primates.