Assessing adaptive and maladaptive stress responses in wild Capuchin monkeys

压力是一个每天影响全球数百万人和动物的问题。大多数关于压力影响的研究都是从生物医学的角度出发，并将重点放在其对健康的负面、非适应性影响上。相比之下，基于行为生态学的研究评估应激反应如何自适应地拯救生物体免受挑战。这两种方法建立的二分法限制了我们对压力的理解，因为最初引发适应性反应的压力可能会及时地产生累积的损失，导致磨损（寿命缩短）或慢性压力（无法引发适应性反应）。为了进一步了解压力反应，特别是社会反应，本研究分析了两个野生灵长类动物种群，它们自然暴露于不同的环境（食物限制的自然时期）和社会（过度拥挤）压力下。这种比较为检测压力反应的变化与个人健康和适应性之间的关系提供了一个强大的工具。这项研究为小学儿童开展了外联活动，建立了实地实验室的能力，并为保护工作作出了贡献。这项研究首次在了解野生灵长类动物应激反应的适应和不适应性质方面取得了前所未有的进展。该研究以生活在两个不同森林的120只野生卷尾猴为研究对象：(1)测量已知社会（如邻近群体之间的攻击）和生态压力（如干旱）前后糖皮质激素的变化；(2)量化每个个体独特的应激反应；(3)确定这些响应是否可重复；(4)确定同一个体对不同应激源的反应是否不同和/或同一应激源是否引起不同个体的不同反应；(5)评估哪些应激反应会对健康产生影响。该研究采用了一种受试者内部的方法，通过测量粪便压力激素（糖皮质激素）在面对已知压力源之前和之后的细微变化。生成的数据为压力诱发的激素水平建立了一个基线，与此相比较的是与压力反应相关的激素水平。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Stress is a problem that affects millions of people and animals across the globe every day. Most studies on the impacts of stress use a biomedical perspective and focus on its negative, non-adaptive effects on health. In contrast, studies based in behavioral ecology assess how stress responses can adaptively rescue organisms from challenges. The dichotomy established by these two approaches limits our understanding of stress because stresses that originally trigger an adaptive response may in time take a cumulative toll resulting in wear-and-tear (reduced longevity) or chronic stress (inability to elicit an adaptive response). To advance knowledge about stress reactivity in general, and social reactivity in particular, this study analyzes two populations of a wild primate that have been naturally exposed to different environmental (natural periods of food restriction) and social (overcrowding) stresses. This comparison offers a powerful tool for detecting how variation in stress responses relate to individual health and fitness. The research develops outreach activities for grade-school children, builds capacity at the field laboratory, and contributes to conservation efforts. This research is the first to make unprecedented gains in understanding the adaptive and maladaptive nature of the stress response in wild primates. The study focuses on 120 wild capuchins living in two different forests to: (1) measure the variation in glucocorticoids before and after known social (e.g., aggression between neighboring groups) and ecological stressors (e.g., droughts); (2) quantify each individual’s unique stress response; (3) determine whether these responses are repeatable; (4) determine if the same individuals respond differently to different stressors and/or if the same stressor induces different responses from different individuals, and; (5) assess which if any stress responses have fitness consequences. The study uses a within-subject approach by measuring fine-scale variation in fecal stress hormones (glucocorticoids) before and after facing a known stressor. The data generated builds a baseline for stress-induced hormone levels against which the levels associated with stress-reaction can be compared.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.