Sizing Up Rivals and Mates in Wild Geladas: Visual, Vocal, and Hormonal Signals

人类通常通过依赖之前与特定个人(个人识别)的经历而获得的信息来评估其他人。事实上，个体识别是大多数灵长类物种的主要评估手段。然而，越来越多的证据表明，人类也使用身体特征(质量信号)。作为评估他人的一种方式？特别是在竞争和交配的背景下。人类可能使用高质量信号的一个原因是，他们生活在非常大的社会群体中，在那里他们经常遇到他们不认识的人。然而，这一假设很难检验，因为高质量的信号在灵长类动物中很少见，而且对信号在非人类灵长类动物中的功能和使用知之甚少。因此，这项研究的主要目的是确定灵长类动物是如何生活在大群体中的？潜在的竞争对手和伴侣？这项任务涉及绘制个人识别在哪里结束，以及其他简单的评估手段在哪里开始的边界。这项研究的对象是野生狐猴(Theropithecus Glada)，这是一种只生活在埃塞俄比亚高地的猴子。出于两个原因，美洲狮是这项研究的理想物种。首先，虽然绝大多数灵长类动物生活在小群体中，每个群体的个体都能识别每一个群体成员，但狐狸(像人类一样)生活在极大的群体中，个人识别可能不会超出一个小的亚群。其次，雄性狐狸在灵长类动物中是不寻常的，它有两个明显的特征可以作为质量信号，胸部和颈部有一块红色的皮肤，以及仪式化的显示发声。通过结合行为观察、实验回放和对粪便类固醇激素的实验室分析，这项研究解决了三个问题：(1)在狐猴社会中，个体识别的极限是什么？(2)对于被认可的个体，他们是否基于这些信息做出生育决定？(3)或者(或者另外)，狐狸是否使用质量信号，如胸色或声音显示，来评估潜在的竞争对手或配偶？该项目的PI和共同PI致力于在几个层面上将研究目标与教育和保护相结合。首先，在这个为期三年的项目中，一名博士后将接受回放实验和激素分析方面的培训，4-6名研究生将获得夏季实地考察经验，6-8名本科生将获得高级论文数据分析经验。第二，预计将有1-3名灵长类行为方面的埃塞俄比亚研究生加入该项目。第三，将资助一名埃塞俄比亚同行进行野生动物管理方面的研究生培训。最后，该项目在西缅山国家公园(目前被列入濒危世界遗产名录)的研究工作正在协助保护工作。到目前为止，已经启动的保护项目包括：对生活在该地区的美洲狮进行普查，对游客进行公园保护调查，以及对当地人进行调查，以衡量人与野生动物冲突的程度。国际和平协会和联合国际组织将继续把他们现场时间的一小部分用于该地区的保护工作。

Humans routinely assess other people by relying on information gained during previous experiences with a particular individual (?individual recognition?). Indeed, individual recognition is the primary means of assessment for most primate species. However, a growing body of evidence indicates that humans also use physical characteristics (?quality signals?) as a way to evaluate others ? particularly in the context of competition and mating. One reason why humans might utilize quality signals is because they live in extremely large social groups where they frequently encounter individuals they do not recognize. However, this hypothesis is difficult to test because quality signals are rare among primates, and little is known about the function and use of signaling in non-human primates. Thus, the main objective of this research is to determine how primates living in large groups ?size up? potential rivals and mates ? a task that involves mapping the boundary of where individual recognition ends and where other short-hand means of assessment begin. The subjects for this research are wild geladas (Theropithecus gelada), a monkey that lives only in the highlands of Ethiopia. Geladas are an ideal species for this research for two reasons. First, while the vast majority of primates live in small groups where individuals recognize every group member, geladas (like humans) live in extremely large groups where individual recognition may not extend beyond a small subgroup. Second, male geladas are unusual among primates in having 2 conspicuous traits that may serve as quality signals, a red patch of skin on the chest and neck, and ritualized display vocalizations. By combining behavioral observations, experimental playbacks, and laboratory analysis of fecal steroid hormones, this research addresses 3 questions: (1) What are the limits of individual recognition in gelada society? (2) For recognized individuals, do they base reproductive decisions on this information? (3) Alternatively (or additionally), do geladas use quality signals, such as chest color or vocal displays, to evaluate potential competitors or mates? The PI and co-PI of this project are committed to integrating research goals with education and conservation at several levels. First, over the course of this three-year project, a post-doc will receive training in playback experiments and hormone analysis, 4-6 graduate students will gain summer field experience, and 6-8 undergraduates will gain experience analyzing data for senior theses. Second, it is expected that 1-3 Ethiopian graduate students in primate behavior will join the project. Third, an Ethiopian counterpart will be sponsored for graduate training in wildlife management. Finally, this project's research presence in the Simien Mountains National Park (currently on the list of World Heritage Sites in Danger) is assisting conservation efforts. Conservation projects that have been initiated thus far include: a census of geladas living in the area, a survey for tourists on park conservation, and a survey for the local people to gauge the degree of human-wildlife conflict. Both the PI and co-PI will continue to dedicate a fraction of their field time to conservation efforts in the area.