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，因为它们能带来健康益处，以婴儿存活率、生育率和净繁殖率衡量。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。慢性应激导致糖皮质激素长期升高，可能严重影响个人健康和生存，也可能对生殖生理产生不利影响。因此，重要的是要了解社会纽带对灵长类个体的重要性，并了解社会纽带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。Hamadryas Baboons(Papio Hamadryas Hamadryas)提供了一个理想的系统，用来研究社会纽带对健康的最新衡量标准的影响，以及缺乏纽带对压力生理学的影响。哈马德里亚人生活在一个多层次的社会系统中，最小的一层是一个男性单位(OMU)。一个OMU，除了一只“领袖”雄性外，还包括一只或多只雌性及其后代，以及次级“追随者”雄性。在灵长类动物中，Hamadryas社会可能是最由男性主导的社会，女性会受到来自领头羊男性的大量攻击，特别是在接管期间和之后。尽管女性将相当大比例的从属互动集中在领导男性身上，但她们也会与其他女性甚至追随者男性形成社会关系。因此，很明显，根据女性所居住的OMU类型的不同，她将形成非常不同的社会纽带，从而对她的健康产生不同的影响。这项研究将在埃塞俄比亚阿瓦什国家公园的Filoha前哨，研究不同类型的OMU中的Hamadryas雌性在Hamadryas Baboons种群中的行为差异。该项目使用短期生殖参数(受孕率和婴儿存活率)以及生理(糖皮质激素)和行为(自我引导行为，如自我梳理、抓挠、自我触摸和摇晃身体)等健康指标，旨在确定社会纽带的强度和质量对女性健康的影响，以及女性是否采取应对特定社会环境的策略。这个项目将考察女性与OMU中每种类型的成年伴侣的关系，并回答有关社会纽带对健康指标和压力水平的影响的问题。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纽带是否对母亲和婴儿都有利，因为他们得到了异地帮助和额外保护，并由于更好的社会融合而降低了压力水平。还将研究雌性与领头羊的关系，以了解雌性是否受益于更宽容的领头羊雄性，允许雌性与其他雌性或追随者建立关系，或者雌性是否受益于更具攻击性的雄性，后者对其幼崽更具保护作用。这项研究将有助于缓慢增长的关于社会支持对动物生理、健康和繁殖影响等因素的知识体系。这项研究将提高人们对灵长类动物社会纽带和应对机制的适应价值的认识，以及两者对压力生理学的影响。通过研究社会单位的不同成员，特别是男性，对婴儿和女性适应能力的影响，这项研究有助于我们理解进化灵长类动物中更大的理论问题，因为异育作用在人类和非人类灵长类的进化中都被认为是重要的。这项研究的结果也可能有助于我们从整体上理解狒狒社会制度的进化和灵长类社会行为的进化。最后，它们与原始人的相似之处使得它们作为原始人起源的模型非常有用，因此这项研究可能有助于我们理解人类的社会进化，特别是具有多层次社会制度和强大的长期雄性-雌性联系的Hamadryas狒狒。

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.