Mitigation of the Effects of Chronic Stress through Social Bonding

在包括人类在内的许多灵长类社会中，个体形成了牢固而持久的社会纽带，这种纽带可以是适应性的，例如，通过增加寿命、后代存活率以及最终的生殖成功。人们对社会纽带发挥作用的机制仍知之甚少。一种可能性是，由于社会纽带在帮助个人应对压力源方面的已知功能，社会纽带缓解了长期压力对健康和生殖的负面影响。但是，日常生活中的社会压力是否以及如何影响灵长类动物的雌性生殖也鲜为人知。这个项目将通过研究社会纽带的变化与健康和生殖措施之间的联系，来解决我们知识中的上述差距。它将评估应激激素是否调节了肠道寄生虫感染的易感性；研究了社会压力与生殖生理之间的关系；以及评估社会纽带是否调节了喂食竞争的成功，从而影响了繁殖所需的能量。该项目的数据将从南非开普敦半岛的三只查克玛狒狒(Papio Ursinus)中收集。该项目的多方面数据将包括：记录压力源和社会纽带的行为观察；通过非侵入性采集的粪便样本测量压力和生殖激素以及肠道寄生虫负载；以及收集尿液C肽(胰岛素生产的副产品)以测量能量平衡。此外，还将进行一项新的现场实验，从随机选择的雌性动物中清除肠道寄生虫，以首次在野生灵长类动物中评估与再次感染的时间和强度有关的因素。利用这一综合方法，这项研究将对连接社会行为、压力生理、健康和生殖的机制产生新的见解，并有助于阐明灵长类社会中社会纽带的功能。由于非人灵长类动物，如狒狒，与人类有许多共同的特征，在研究人类生物学的各个方面都很有用，这个项目将通过阐明社会压力作为寄生虫感染风险因素的作用，提高人们对社会性在人类进化过程中的好处的理解，并具有临床意义。该项目将加强美国和南非之间的机构联系，培训在科学领域代表性不足的学生，并提供宝贵的数据和教育资源，以帮助管理和保护灵长类动物。

In many primate societies, including humans, individuals form strong, long-lasting social bonds which can be adaptive, for example, by increasing longevity, offspring survival, and, ultimately, reproductive success. What is still poorly understood are the mechanisms by which social bonds achieve their effects. One possibility is that, because of their known function in helping individuals cope with stressors, social bonds mitigate negative effects of chronic stress on health and reproduction. But whether, and how, daily-life social stress influences female reproduction in primate societies also is poorly understood. This project will address both of the above gaps in our knowledge by examining the pathways connecting variation in social bonds with measures of health and reproduction. It will assess whether stress hormones mediate the susceptibility to intestinal parasite infections; examine the relationship between social stress and reproductive physiology; and evaluate whether social bonds mediate success in feeding competition, and hence, energy available for reproduction. Data for this project will be collected from three troops of chacma baboons (Papio ursinus) in the Cape Peninsula of South Africa.The project's multifaceted data will include behavioral observations to document sources of stress and social bonds; measurement of stress and reproductive hormones, as well as intestinal parasite loads, via non-invasively collected fecal samples; and collection of urinary C-peptide (a byproduct of insulin production) to measure energy balance. Additionally, a novel field experiment will be conducted in which intestinal parasites are eliminated from a random selection of females to assess, for the first time in a wild primate, the factors associated with the timing and intensity of re-infection. Utilizing this comprehensive approach, the research will generate new insights into the mechanisms linking social behavior, stress physiology, health, and reproduction, and help elucidate the function of social bonds in primate societies. Because non-human primates such as baboons share many traits with humans and are useful in studying aspects of human biology, this project will improve understanding of the benefits of sociality during human evolution and carry clinical implications by elucidating the role of social stress as a risk factor for parasite infections. The project will strengthen institutional ties between the U.S. and South Africa, train students underrepresented in science, and provide valuable data and educational resources to aid in management and conservation of primates.