Collaborative Research: Competition within and between primate social groups: Hormonal and behavioral signatures

生活在不同规模的社会群体中的成本和收益是什么？理论预测，生活在较小的群体中应该会缓解群体内部对资源的竞争。但在更大的群体中生活，在群体之间的竞争中提供了一种优势。这些在群体内竞争(有利于较小群体)和群体间竞争(有利于较大群体)之间的权衡可能意味着，生活在中等规模的群体中是社会物种的最佳策略。然而，这一假设很少得到检验，基本的问题仍然是个人和群体之间的竞争如何影响个人的精力状况，并最终影响繁殖和生存。这项研究将通过分析野生灵长类动物中的甲状腺激素来解决这些问题，甲状腺激素是新陈代谢和能量平衡的调节器，以了解群体规模、不同类型的竞争和能量状况之间的关系。这项研究将集中在安博塞利浣熊研究项目研究了超过45年的肯尼亚野生狒狒种群。为了追求这一创新的研究方向，研究人员将使用一个储存库，其中包含在连续12年中从200多只成年雌性鹦鹉身上收集的大约8000份已经获得的狒狒粪便样本。甲状腺激素代谢物将与一个丰富的数据集进行比较，其中包括关于个体群体成员、群体规模、群体运动、繁殖和寿命等信息，以测试围绕不同规模群体生活的好处的预测。与研究目标一致，研究人员将培养STEM人才，并通过以下方式扩大代表不足的群体在行为生态学和生物人类学领域的参与：(1)为全职研究技术人员提供就业和培训；(2)指导石溪大学的毕业生和杜克大学的本科生；以及(3)制定和实施可持续的课后行为科学计划，目标是来自高需求地区的中学生。这项研究由生物科学局的行为系统计划和社会、行为和经济科学局的生物人类学计划共同资助。资源竞争如何影响群居哺乳动物的生存和繁殖是行为生态学和生物人类学的中心课题。这项研究将通过经验性地评估野生灵长类种群中社会群体内部和社会群体之间的资源竞争之间的紧张关系来直接解决这个问题。为了做到这一点，研究人员将量化大约8000个已经从成年雌性狒狒身上获取的粪便样本中的甲状腺激素浓度。中心前提是，甲状腺激素浓度的变化提供了个体能量状况的可量化指数，该指数将随着群体内部和群体之间对能源资源的竞争而变化。结果数据将结合有关女性个人和社会群体的详细数据进行分析。个人层面的数据将包括社会地位、年龄、生殖状态、饮食和竞争互动；群体层面的数据将包括群体规模、群体水平的范围模式、群体间的相遇和群体的稳定性。研究的目的是：(1)加强我们现有的粪便甲状腺激素分析的生物学有效性；(2)量化社会等级和群体规模的能量后果；(3)评估通过群体裂变事件发生的群体规模变化的能量预测因素和后果；以及(4)了解能量和心理社会过程对女性内分泌变化的相对贡献。这一新的方法将提供一个前所未有的窗口，了解社会等级和群体规模带来的能量后果，很少被应用于野生灵长类动物的研究，也从未被应用于任何如此规模和范围的项目。这一奖项反映了NSF的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。

What are the costs and benefits of living in social groups of different sizes? Theory predicts that living in smaller groups should ease competition for resources within groups. But living in larger groups provides an advantage in competition between groups. These trade-offs between within-group competition (favoring smaller groups) and between-group competition (favoring larger groups) may mean that living in intermediate-sized groups is the best strategy for social species. However, this hypothesis has rarely been tested, and basic questions remain about how competition between individuals and groups affect an individual's energetic condition, and ultimately reproduction and survival. This study will address these questions by analyzing thyroid hormones - a modulator of metabolism and energy balance - in wild primates, in order to understand the relationship between group size, different types of competition, and energetic condition. The research will focus on a wild baboon population in Kenya studied for more than 45 years by the Amboseli Baboon Research Project. To pursue this innovative research direction, investigators will use a repository of approximately 8,000 already-acquired baboon fecal samples collected over a continuous 12-year period from over 200 adult females. Thyroid hormone metabolites will be compared to a rich dataset including information on individual group membership, group size, group movements, reproduction, and life span, among other information, to test the predictions surrounding the benefits of living in groups of varying size. In concert with the research goals, the investigators will build STEM talent and broaden participation of under-represented groups in behavioral ecology and biological anthropology by: (1) providing employment and training for a full-time research technician; (2) mentoring Stony Brook University graduate and Duke undergraduate students; and (3) developing and implementing a sustainable after school program in behavioral science that targets middle school students from high-needs districts. This research is co-funded by the Behavioral Systems Program in the Directorate for Biological Sciences and the Biological Anthropology Program in the Directorate for Social, Behavioral and Economic Sciences. How resource competition affects survival and reproduction in social mammals is a central topic in behavioral ecology and biological anthropology. This research will address this topic directly by empirically evaluating the tension between resource competition within and between social groups in a wild primate population. To do so, the investigators will quantify the concentration of thyroid hormones in approximately 8,000 already-acquired fecal samples from adult female baboons. The central premise is that variation in thyroid hormone concentrations provides a quantifiable index of individual energetic condition, which will vary as a function of competition for energy resources within and between groups. The resulting data will be analyzed in combination with detailed data on individual females and on social groups. Individual-level data will include social status, age, reproductive state, diet, and agonistic interactions; group-level data will include group size, group-level ranging patterns, intergroup encounters, and group stability. The research aims are to: (1) enhance our existing biological validation of fecal thyroid hormone analysis; (2) quantify the energetic consequences of social rank and group size; (3) assess the energetic predictors and consequences of changes in group size that occur through group fission events; and (4) understand the relative contributions of energetic versus psychosocial processes to variation in female endocrine profiles. This novel approach, which will provide an unprecedented window into the energetic consequences of social rank and group size, has rarely been applied to the study of wild primates and has never been applied to any project of this scale and scope.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.