As human-modified landscapes encroach into natural habitats, wildlife face a reduction in natural food sources but also gain access to calorie-rich, human-derived foods. However, research into the energetics of wildlife living within and adjacent to urban and rural landscapes is lacking. C-peptide - a proxy for insulin production and a diagnostic tool for assessing pancreatic function in humans and domestic animals - can be quantified non-invasively from urine (uCP) and may provide a way to investigate the energetic correlates of living in human-altered landscapes. UCP is increasingly used in studies of primate energetics, and here we examine predictors of variation in uCP levels in n = 17 wild chacma baboons (Papio ursinus) living at the urban edge on the Cape Peninsula, South Africa. We find that uCP was positively associated with food provisioning and negatively with night fasting. UCP levels were comparable between winter and summer but significantly lower during spring, possibly driven by consumption of energy-rich seeds during summer and more human-derived foods during winter. UCP was elevated in pregnant females and similar for lactating and cycling females. We find no effect of dominance rank on uCP. Samples collected with synthetic Salivettes had significantly lower uCP levels than directly pipetted samples. Overall, our results indicate that uCP is a reliable, non-invasive measure of energy balance and intake in baboons, and suggest potential energetic benefits of living at the urban edge. More broadly, studies of uCP may offer unique insight into the environmental control of hormone-behaviour relationships in species crossing natural and urban environments.

随着人类改造的景观侵入自然栖息地，野生生物面临着天然食物来源的减少，但也获得了热量丰富的人类食品。然而，缺乏对生活在城市和乡村景观之内和附近的野生动植物能量的研究。C肽-胰岛素产生的代理和评估人类和家畜的胰腺功能的诊断工具-可以通过尿液（uCP）进行非侵入性定量分析，并可以提供一种方法来研究人类改变后生活的能量相关性风景。UCP越来越多地用于灵长类动物能量学的研究中，在这里，我们研究了n = 17个野生Chacma狒狒（Papio ursinus）中uCP水平变化的预测因子）居住在南非海角半岛的城市边缘。我们发现uCP与食物供应有正相关，而与空腹则有负相关。冬季和夏季的UCP水平相当，但春季时的UCP水平却明显较低，这可能是由于夏季食用能量丰富的种子以及冬季食用更多人类食品所致。孕妇的UCP升高，哺乳期和骑自行车的女性UCP升高。我们发现优势等级对uCP没有影响。与合成移液器收集的样品相比，直接移液样品的uCP水平明显降低。总体而言，我们的结果表明，uCP是狒狒能量平衡和摄入量的可靠，非侵入性测量方法，并暗示了生活在城市边缘的潜在能量收益。更广泛地，