Doctoral Dissertation Improvement: Reproductive Strategies of Male White-Faced Capuchins (Cebus capucinus) in the Santa Rosa Sector of the ACG, Costa Rica

本研究的研究目的是通过收集哥斯达黎加Área de Conservación瓜纳卡斯特圣罗莎地区三组C. capucinus的雄性行为数据、两性激素数据和遗传数据，研究优势雄性如何以及为什么会产生最多的后代。性选择理论认为，因为有生育能力的雌性是一种有限的资源，雄性应该为获得它们而竞争，因此只表现出低水平的合作。白面卷尾猴（Cebus capucinus）生活在多个相关的雌性和移民雄性的群体中。虽然C. capucinus的社会系统是基于群体中雌性的紧密联系，但它也包括群体中雄性的合作联盟。在群体内，雄性之间的攻击和公开的交配竞争是罕见的，所有的雄性都参与交配系统。社会生态学模型预测，当群体内竞争低而群体间竞争高时，雄性应该有同等的繁殖成功率。然而，与理论预测和行为观察相反，占统治地位的雄性会产生大多数后代。智力优势：这项研究是为数不多的同时收集男性和女性荷尔蒙数据的项目之一。结合行为和遗传数据，这些数据将有助于正在进行的生殖偏态理论研究，了解男性生殖成功变异的近因，测试挑战假说的适用性，并增加可为人类进化提供见解的比较数据的可用性。更广泛的影响：该项目将为圣罗莎卷尾猴的长期（25年以上）研究数据库做出贡献，同时也为当地和外国助理提供宝贵的现场技术使用培训。本博士论文研究项目将有助于一名女研究生的学术训练。

The research objective of this study is to examine how and why dominant males sire the most offspring by collecting behavioral data on males, hormonal data on both sexes, and genetic data in three groups of C. capucinus in the Santa Rosa Sector of the Área de Conservación Guanacaste, Costa Rica. Sexual selection theory suggests that because fertile females are a limited resource, males should compete over access to them and therefore display only low levels of cooperation. White-faced capuchins (Cebus capucinus) live in groups of multiple related females and immigrant males. While the social system of C. capucinus is based on close bonds among group females, it also involves cooperative alliances among group males. Within-group male-male aggression and overt mating competition are rare, with all males participating in the mating system. The socioecological model predicts that when within-group competition is low and between group competition is high, males should have equal reproductive success. Yet, contrary to theoretical predictions and behavioral observations, dominant males sire the majority of offspring. Intellectual Merit: This study is one of few projects involving the simultaneous collection of hormonal data on males and females. In combination with behavioral and genetic data, these data will to contribute to on-going research on reproductive skew theory, to understand proximate causes of variation in male reproductive success, to test the applicability of the Challenge Hypothesis, and to increase the availability of comparative data which can provide insight into human evolution. Broader Impacts: This project will contribute to the database of long-term (25+ years) research on the capuchins of Santa Rosa, while also providing invaluable training for local and foreign assistants in the use of field techniques. This doctoral dissertation research project will contribute to the academic training of a female graduate student.