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缓解群体内对资源的竞争。 但是，生活在较大的群体提供了一个优势，在群体之间的竞争。群内竞争（有利于较小的群体）和群间竞争（有利于较大的群体）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，这一假设很少得到验证，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充沛的状态，并最终繁殖和生存。本研究将通过分析野生灵长类动物的甲状腺激素-代谢和能量平衡的调节剂-来解决这些问题，以了解群体大小，不同类型的竞争和精力充沛的状态之间的关系。这项研究将集中在肯尼亚的一个野生狒狒种群，该种群已被安博塞利狒狒研究项目研究了45年以上。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，其中储存了大约8,000个已经获得的狒狒粪便样本，这些样本是在连续12年的时间里从200多只成年雌性狒狒身上收集的。甲状腺激素代谢物将与丰富的数据集进行比较，包括个人群体成员身份，群体规模，群体运动，繁殖和寿命等信息，以测试围绕生活在不同规模群体中的益处的预测。 为了实现研究目标，研究人员将培养STEM人才，并扩大行为生态学和生物人类学中代表性不足的群体的参与：（1）为全职研究技术人员提供就业和培训;（2）指导斯托尼布鲁克大学毕业生和杜克大学本科生;以及（3）针对高需求地区的中学生，制定和实施可持续的行为科学课后计划。 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。 资源竞争如何影响社会性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议题。本研究将解决这个问题，直接通过经验评估资源竞争之间的紧张关系，在野生灵长类动物种群的社会群体内部和之间。为了做到这一点，研究人员将量化大约8,000个已经获得的成年雌性狒狒粪便样本中的甲状腺激素浓度。其核心前提是甲状腺激素浓度的变化提供了一个可量化的指标，个人的精力充沛的条件，这将是不同的功能内和组之间的能量资源的竞争。将结合关于女性个人和社会群体的详细数据对所得数据进行分析。个体层面的数据将包括社会地位、年龄、生殖状态、饮食和竞争性相互作用;组层面的数据将包括组规模、组层面的范围模式、组间遭遇和组稳定性。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验证;（2）量化社会等级和群体规模的能量后果;（3）评估通过群体分裂事件发生的群体规模变化的能量预测因子和后果;（4）了解能量与心理社会过程对女性内分泌特征变化的相对贡献。这种新颖的方法，将提供一个前所未有的窗口到社会等级和群体规模的能量后果，很少被应用到野生灵长类动物的研究，从来没有被应用到任何项目的这种规模和范围。这个奖项反映了NSF的法定使命，并已被认为是值得通过评估使用基金会的智力价值和更广泛的影响审查标准的支持。

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.