Are measures of sociality linked to Oxytocin and Glucocorticoid profiles and health in wild chimpanzees (Pan troglodytes verus)?

压力激素水平长期升高是由于反复暴露于压力源，可能导致人类和其他社会性哺乳动物的免疫抑制、健康状况不佳和寿命延长。在许多灵长类动物中，暴露于压力源的有害影响可以通过社会应对策略来减轻，尽管对这种策略的近似机制知之甚少。在黑猩猩中，最近的研究表明，维持密切的社会关系有助于调节糖皮质激素水平。我们将评估在象牙海岸Taï国家公园的三个野生黑猩猩社区中，两种社会应对策略如何以及在多大程度上影响激素分布和健康参数。社会整合假说认为，在一个社会群体中保持身体或社会中心地位，例如通过支配地位，将最大限度地减少暴露于环境和社会压力源（季节影响、食物或性竞争）。社会纽带假说认为，拥有亲密的社会纽带伙伴可以缓冲压力源的有害影响，即使压力源暴露程度很高。我们预测，使用而不是不使用任何一种应对策略的个体将经历更低的平均糖皮质激素水平和更少的病原体感染，通过病毒载量和尿新蝶呤水平来衡量。此外，虽然我们认为社会融合的好处是受到攻击的几率较低，但我们认为保持密切的社会关系的好处是每天与伴侣保持高频率的联系，比如梳理毛发，这与催产素的释放有关。因此，伴侣梳理率应该与较高的平均尿后叶催产素水平和较低的平均尿糖皮质激素水平相关。这项研究将使我们能够调查野生黑猩猩的社会性和健康的不同参数之间的关系，包括了解潜在机制的各个方面。

Chronically elevated stress hormone levels occur from repeated exposure to stressors and can result in immuno-suppression, poor health and longevity in humans and other social mammals. In a number of primate species, deleterious effects of exposure to stressors can be mitigated through social coping strategies although little is known about the proximate mechanisms underlying such strategies. In chimpanzees, recent research shows that maintaining close social relationships can help regulate glucocorticoid levels. We will assess how and to what extent two social coping strategies impact on hormone profiles and health parameters in three communities of wild chimpanzees, in Taï National Park, Ivory Coast. The Social integration hypothesis states that maintaining either physically or socially central positions within a social group, such as through dominance, will minimize exposure to environmental and social stressors (seasonal effects, food or sexual competition). The social bonds hypothesis states that having close social bond partners should buffer the deleterious effects of stressors, even when exposure to stressors is high. We predict that individuals utilising, rather than not utilising, either coping strategy will experience lower average glucocorticoid levels and fewer pathogen infections, measured by virus load and urinary neopterin levels. In addition, whilst we expect benefits from social integration to be characterised by lower rates of received aggression, we expect benefits from maintaining close social bonds to be characterised by high rates of repeated, daily bond partner affiliations, such as grooming, which are associated with oxytocin release. Thus, bond partner grooming rates should correlate with higher average urinary oxytocin levels and lower average urinary glucocorticoid levels. This study will allow us to investigate the relationship between different parameters of sociality and health in wild chimpanzees including understanding aspects of the underlying mechanisms.