Most primates live in habitats with some level of anthropogenic disturbance, and such disturbances have a larger impact on frugivorous primates that are more sensitive to ecological disruptions than folivores. Fecal glucocorticoid metabolites provide insight into how the external environment affects internal physiological state, and thus provide information on how anthropogenic pressures become embodied. Here, I examine how subgroup size and glucocorticoids vary with high and low fruit abundance, and how fruit abundance, subgroup size, and activity budget affect fecal glucocorticoid metabolites in female spider monkeys (Ateles geoffroyi) living in an anthropogenically disturbed habitat. I measured these variables via behavioral, ecological, and fecal sampling for 15 months in 17 female spider monkeys at El Zota Biological Field Station. Subgroup size was significantly larger during periods of high fruit abundance, but glucocorticoids did not differ between periods of low and high fruit abundance. Monthly fruit abundance predicted subgroup sizes significantly, but did not predict fecal glucocorticoid concentrations. Increased resting time and reproductive state predicted fecal glucocorticoid concentrations significantly, but travel and foraging time had no significant effect on glucocorticoid concentrations. Individual resting time over the study period correlated negatively with glucocorticoid concentrations. These results suggest that spider monkeys cope with variation in fruit abundance by adjusting subgroup size, and that these adjustments may mitigate environmental stress in this mildly seasonal environment. The large, relatively productive forest size at this site, and the availability of anthropogenic food sources, enable this population of spider monkeys to cope with human-induced habitat disturbance.

中文翻译：

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雌性蜘蛛猴（Ateles geoffroyi）通过裂变融合动力学应对人为干扰

大多数灵长类动物生活在受到一定程度人为干扰的栖息地，这种干扰对食果灵长类动物的影响更大，与食叶动物相比，它们对生态破坏更敏感。粪便糖皮质激素代谢物可以洞察外部环境如何影响内部生理状态，从而提供有关人为压力如何体现的信息。在这里，我研究了亚群大小和糖皮质激素如何随着果实丰度的高低而变化，以及果实丰度、亚群大小和活动预算如何影响生活在人为干扰栖息地的雌性蜘蛛猴 (Ateles geoffroyi) 的粪​​便糖皮质激素代谢物。我通过 El Zota 生物野外站的 17 只雌性蜘蛛猴的行为、生态和粪便采样 15 个月测量了这些变量。在果实丰度高的时期，亚组大小明显更大，但糖皮质激素在果实丰度低和果实丰度高的时期没有差异。每月水果丰度显着预测亚组大小，但不能预测粪便糖皮质激素浓度。休息时间和生殖状态的增加显着预测粪便糖皮质激素浓度，但旅行和觅食时间对糖皮质激素浓度没有显着影响。研究期间的个人休息时间与糖皮质激素浓度呈负相关。这些结果表明，蜘蛛猴通过调整亚群大小来应对果实丰度的变化，并且这些调整可以减轻这种温和的季节性环境中的环境压力。该地点的大片、相对多产的森林面积，