Doctoral Dissertation Research: Cooperation, grooming exchange, and supply and demand among free-ranging primates

人类的一个决定性特征是他们不同寻常的合作天性，这在动物中是无与伦比的。人类学的一个重要目标是理解这种“利他”行为的本质和进化。这个博士论文项目将调查自由放养的恒河猴之间的合作交流，以测试从几个竞争的利他主义进化假说的预测。研究恒河猴之间的合作交流将为理解人类和我们祖先的行为进化提供一个比较模型。该项目的更广泛影响包括通过研究助理的宝贵实地经验，本科生的数据分析经验，以及在各种公共形式（包括当地动物园和会议）中展示研究成果，支持科学教育和推广。本研究将观察来自波多黎各圣地亚哥岛三个社会群体的50只成年雌性恒河猴之间的梳理互动。使用焦点动物采样方法，持续11个月（跨越交配和出生季节）。具体而言，该项目将研究互惠梳理交流如何类似于几个竞争的理论假设（亲属选择，互惠利他主义，生物市场理论和社会债券投资），在一个全面和综合的分析，通过AIC模型排名预测。这些交流将在多个时间尺度和不同规模的群体中进行审查。此外，还将对生物市场理论进行更详细的研究。通过关注配偶的梳理或婴儿处理的交换，本研究将检验一个关键的预测，即这种交换符合供求关系。在何种程度上，明显的供应和需求关系可能是文物，或介导的，压力反应将进行检查，与压力测量行为和通过粪便糖皮质激素代谢物测定。

One defining characteristic of humans is their unusually cooperative nature, which is unparalleled among animals. An important goal for anthropology is to understand the nature and evolution of this "altruistic" behavior. This doctoral dissertation project will investigate cooperative exchanges among free-ranging rhesus macaques in order to test predictions from several competing evolutionary hypotheses about altruism. Studying cooperative exchanges among rhesus macaques will provide a comparative model for understanding the behavioral evolution of humans and our ancestors. The broader impacts of this project include the support of science education and outreach, through valuable field experience for research assistants, data analysis experience for undergraduates, and presentation of research results in various public formats, including local zoos and conferences.This study will observe grooming interactions among 50 adult female rhesus macaques from three social groups at Cayo Santiago, Puerto Rico, using focal animal sampling methodology, for eleven months (spanning both mating and birth seasons). Specifically, the project will examine how well reciprocal grooming exchanges resemble those predicted by several competing theoretical hypotheses (kin selection, reciprocal altruism, biological markets theory, and social bond investment), in one comprehensive and integrated analysis, via AIC model ranking. These exchanges will be examined across multiple time scales and across groups of variable sizes. Additionally, there will be a more detailed investigation of biological markets theory. By focusing on exchanges of grooming for mates or infant handling, this study will test a key prediction that such exchanges conform to supply and demand relationships. The extent to which apparent supply and demand relationships may be artifacts of, or mediated by, stress responses will be examined, with stress measured both behaviorally and via fecal glucocorticoid metabolite assays.