Doctoral Dissertation Improvement: Variation in Female Social Lives in a Male-Dominated Society: Bonds, Stress, and Reproduction in Female Hamadryas Baboons

社会性和社会关系对人类和非人类灵长类动物都很重要，因为它们会带来健康效益，以婴儿存活率、生育率和净繁殖率来衡量。另一方面，缺乏社会支持已被证明与人类和非人类灵长类动物的慢性压力有关。慢性压力，通过引起糖皮质激素的长期升高，可以严重影响个人健康和生存，也可以对生殖生理产生不利影响。因此，了解社会关系对个体灵长类动物的重要性，了解社会关系对健康的有益影响以及缺乏社会支持对应激生理的负面影响是很重要的。Hamadryas狒狒（Papio Hamadryas Hamadryas）提供了一个理想的系统来研究社会关系对健康的近似测量和缺乏社会关系对应激生理的影响。哈马德亚人生活在一个多层次的社会系统中，最小的层次是一个男性单位（OMU）。一个OMU，除了一个“领导”雄性，可变地包含一个或多个雌性和它们的后代，以及次要的“追随者”雄性。Hamadryas社会可能是灵长类动物中男性主导程度最高的社会，雌性从雄性领袖那里受到大量的攻击，尤其是在被征服期间和之后。尽管雌性将相当大比例的从属互动集中在雄性领袖身上，但它们也会与其他雌性甚至是追随者建立社会关系。因此，很明显，根据雌性所处的OMU类型的不同，她会形成非常不同的社会关系，从而对她的适应性产生不同的影响。本研究将在埃塞俄比亚阿瓦什国家公园菲洛哈前哨的一个hamadryas狒狒种群中，研究不同类型的omu中hamadryas雌性狒狒的行为变化。本项目利用短期生殖参数（受孕率和婴儿存活率）、生理（糖皮质激素）和行为（自我导向行为，如自我梳理、抓挠、自我触摸和身体颤抖）压力指标等适应度的近似测量方法，旨在确定社会关系的强度和质量对女性适应度的影响，以及女性是否锻炼策略来应对特定的社会环境。该项目将研究女性与OMU中每种类型的成年伴侣的关系，并回答有关社会关系对健康指标和压力水平影响的问题。通过研究女性与其他女性以及与追随者男性的关系，该项目旨在阐明与他人的社会关系是否以异体父母的帮助和额外的保护以及由于更好的社会融合而降低的压力水平的形式对母亲和婴儿都有益。女性与雄性领袖的关系也将被研究，以了解女性是否受益于更宽容的男性领袖，他们允许女性与其他女性或追随者男性建立关系，或者女性是否受益于更具侵略性的男性，他们更保护自己的孩子。这项研究将有助于对诸如社会支持对动物生理、健康和繁殖等因素的影响的缓慢增长的知识体系。这项研究将提高对灵长类动物社会关系的适应价值和应对机制的认识，以及它们对应激生理的影响。通过研究不同社会单位成员（尤其是雄性）对婴儿和雌性适合度的影响，本研究有助于我们理解进化灵长类学中更大的理论问题，因为异源养育在人类和非人类灵长类动物的进化中都很重要。这项研究的结果也可能有助于我们理解狒狒社会系统的进化和灵长类动物社会行为的进化。最后，它们与原始人类的相似性使得狒狒，特别是具有多层次社会系统和强大的长期雄性雌性关系的hamadryas狒狒，非常有用的原始人类起源模型，因此这项研究可能有助于我们对人类社会进化的理解。

Sociality and social relationships are important to both human and non-human primates because they lead to fitness benefits, measured by infant survival, fertility and net reproductive rates. Lack of social support, on the other hand, has been shown to be associated with chronic stress in human and non-human primates. Chronic stress, by causing prolonged elevation of glucocorticoid hormones, can severely impact individual health and survival and can also adversely affect reproductive physiology. Thus it is important to understand the importance of social bonds to individual primates, and to understand both the beneficial effects of social bonds on fitness as well as the negative impacts of the lack of social support on stress physiology. Hamadryas baboons (Papio hamadryas hamadryas) provide an ideal system in which to study the effects of social bonds on proximate measures of fitness and the lack of bonds on stress physiology. Hamadryas live in a multi-level social system with the smallest level being a one-male unit (OMU). An OMU, in addition to a "leader" male, variably contains one or more females and their offspring, as well as secondary "follower" males. Hamadryas society is probably the most male-dominated society among primates and females receive a substantial amount of aggression from leader males, especially during and after takeovers. Even though females focus a sizeable proportion of their affiliative interactions on the leader male, they also form social relationships both with other females and even follower males. It is obvious, therefore, that depending on the type of OMU in which a female resides, she will form very different social bonds with consequent variable effects on her fitness. This study will examine variation in the behavior of hamadryas females across different types of OMUs in a population of hamadryas baboons at the Filoha outpost of the Awash National Park in Ethiopia. Using proximate measures of fitness, such as short-term reproductive parameters (conception rates and infant survival), and both physiological (glucocorticoid hormones) and behavioral (self-directed behavior such as self-grooming, scratching, self-touching and body-shaking) indicators of stress, this project aims to determine the effect on female fitness of the strength and quality of social bonds and whether females exercise strategies to cope with their specific social environment. This project will examine a female's relationships with each type of adult partner available to her in an OMU and answer questions addressing the effects of social bonds on fitness measures and stress levels. By examining female relationships with other females as well as with follower males, this project aims to elucidate whether social bonds with others benefit both mothers and infants in the form of alloparental help and extra protection received as well as lower stress levels due to better social integration. Female relationships with the leader male will also be studied to understand whether females benefit from more tolerant leader males who allow females to have relationships with other females or follower males, or whether females benefit from more aggressive males who are more protective towards their infants.This study will contribute to the slowly growing body of knowledge about the effects of factors such as the availability of social support on the physiology, health and reproduction of animals. This research will improve knowledge of the adaptive value of social bonds and coping mechanisms in primates and the effects of both on stress physiology. By examining the effects on infants and female fitness of alloparenting by various members of the social unit, particularly by males, this study can contribute to our understanding of larger theoretical questions in evolutionary primatology, as alloparenting has been suggested to be important in the evolution of both human and non-human primates. The results of this study may also contribute to our understanding of the evolution of baboon social systems and the evolution of social behavior in primates as a whole. Lastly, their similarities with hominids make baboons, especially hamadryas baboons with their multi-level social system and strong long-term male-female bonds, very useful as models of hominid origins and this study may therefore contribute to our understanding of human social evolution.