Effects of progressing age on energy balance, sociality and health in wild female Assamese macaques (Macaca assamensis)

随着年龄的增长，人类的社会活动减少，在选择伴侣时变得越来越挑剔，更喜欢有价值的关系，而不是没有意义的关系。这种社会情感的选择性归因于老年人有限的时间观念。社会活动和社会伙伴数量的减少也是非人灵长类动物在没有时间意识的情况下年龄增长的特征。我们认为，随着年龄的增长，社会活动的下降是由能量的限制，由于年龄相关的觅食性能，能量摄入和能量平衡的下降。精力不足和社交能力下降会造成精力和社交压力，预计会影响生理压力水平，进而影响个人的健康。在这个项目中，我们的长期研究人口的野生阿萨姆猕猴面临着明显的自然变化的能源供应，我们结合联合收割机数据年龄对食物摄入量和能量预算的影响，社会融合的措施，营养和社会压力的生理措施与健康指标，特别是肠道微生物群落和非特异性免疫标记。该项目有三个主要目标。首先，我们将添加到野生种群在自然生态条件下，使我们能够整合精力充沛的限制，作为一个重要的，但很少调查的因素限制社会活动的行为老年学的少数研究。其次，我们的目标是分离生理反应的营养和社会压力的老年人所经历的同时测量非特异性应激标志物（糖皮质激素）和营养应激标志物（甲状腺激素）。最后，我们的目标是将与年龄有关的精力限制、生理压力反应和社会融合措施与健康指标联系起来。总之，这些数据将有助于全面了解随着年龄的增长，精力充沛的因素对社会活动和选择性的作用，并将为人类行为老年学研究提供信息。

As humans age they decrease their social activity and become increasingly selective in their choice of partners favoring valuable relationships over less meaningful ones. This socio-emotional selectivity has been attributed to the limited time perspective of elderly humans. A decline in social activity and number of social partners are also characteristics of increasing age in nonhuman primates in the absence of awareness of limited time. We propose that the declining social activity with progressing age is driven by energetic constraints due to age-related decreases in foraging performance, energy intake and energy balance. Energetic constraints and decreasing sociality pose energetic and social stressors and are expected to influence physiological stress levels which in turn impact an individual´s health. In this project on our long-term study population of wild Assamese macaques facing pronounced natural variation in energy availability, we combine data on age effects on food intake and energy budget, measures of social integration, physiological measures of nutritional and social stress with indicators of health, specifically the gut microbial community and a non-specific immune marker. This project has three main goals. First, we will add to the few studies on behavioral gerontology in wild populations under natural ecological conditions which enables us to integrate energetic constraints as an important but rarely investigated factor limiting social activity. Second, we aim to separate physiological responses to nutritional and social stressors experienced by aged individuals by simultaneously measuring a non-specific stress marker (glucocorticoids) and a nutritional stress marker (thyroid hormone). Lastly, we aim to link age-related energetic constraints, physiological stress responses and measures of social integration to health indicators. Together, these data will contribute to a comprehensive understanding of the role of energetic factors on social activity and selectivity with increasing age and will inform studies on human behavioral gerontology.