Doctoral Dissertation Improvement: C-peptide of Insulin as an Index of Energy Expenditure in Wild Chimpanzees

乌干达Kibale国家公园将对黑猩猩进行观察，以检验成年雄性黑猩猩尿液C-肽(UCP)水平的日变化与食物摄入量和攻击性等高能量行为相关的假设。C-肽分子是胰岛素合成的副产物，当从尿液中排泄出来时，可以准确地指示胰岛素的生成。胰岛素能刺激血液中葡萄糖的吸收，从而反映机体能量的可获得性。这项研究将首次直接评估C肽作为野生灵长类动物能量平衡指标的有效性。之前的评估一直是间接的，因为他们使用的是每月平均的饮食质量，而不是对个人行为的日常监测。这项研究旨在解释为什么据报道，优势雄性黑猩猩的UCP水平低于从属黑猩猩，尽管UCP水平跟踪能量摄入量，在水果可获得性较高的时间和地点更高。这项研究的智力价值在于其研究结果将对野外条件下能量学研究的方法论发展产生可能的影响。灵长类动物精力状况的非侵入性指标一直难以捉摸。C-肽作为能量平衡、能量摄入或能量消耗的指标很有前景，这项研究将评估其价值。了解雄性黑猩猩的能量消耗与它们的优势等级之间的关系，也将揭示迄今为止被忽视的群居母猩猩统治的能量成本。该项目的更广泛影响包括对Makerere大学生物野外站功能的贡献。将在当地学校开展教育项目，以提高人们对野生动物的认识和兴趣。这一博士论文研究项目将有助于研究生的学术培训，其结果将发表在同行评议的期刊上。

Chimpanzees will be observed in Kibale National Park, Uganda, to test the hypothesis that daily variation in urinary C-peptide (UCP) levels among adult males is correlated with both food intake and energetically expensive behaviors, such as aggression. The C-peptide molecule is a by-product of insulin synthesis and when excreted in the urine gives an accurate indication of insulin production. Insulin stimulates the uptake of glucose from the bloodstream and thus reflects the availability of energy for the organism.This study will provide the first direct assessment of the effectiveness of C-peptide, as an index of energy balance in wild primates. Previous assessments have been indirect since they used monthly averages of dietary quality, rather than daily monitoring of individual behavior. This research is designed to explain why dominant male chimpanzees have been reported to have lower UCP levels than subordinates, even though UCP levels track energy intake, being higher when and where fruit availability is greater.The intellectual merit of this study lies in the possible implications its findings will have for the methodological development of energetics research in field conditions. Non-invasive indices of the energetic condition of primates have always been elusive. C-peptide is promising as an indicator of energetic balance, energy intake, or energy expenditure and this study will assess its value. Understanding the relationship between energy expenditure in male chimpanzees and their dominance rank will also reveal hitherto overlooked energetic costs of dominance in social mammals.The broader impacts of the project include the contribution to the functioning of Makerere University Biological Field Station. Educational programs will be carried out in local schools to raise awareness and interest in wildlife. This doctoral dissertation research project will contribute to the academic training of a graduate student and the results will be published in peer-reviewed journals.