A novel integrative method for measuring body condition in ecological studies based on physiological dysregulation

1. The body condition of free-ranging animals affects their response to stress, decisions, ability to fulfil vital needs and, ultimately, fitness. However, this key attribute in ecology remains difficult to assess, and there is a clear need for more integrative measures than the common univariate proxies. 2. We propose a systems biology approach that positions individuals along a gradient from a ‘normal/optimal’ to ‘abnormal/suboptimal’ physiological state based on Mahalanobis distance computed from physiological biomarkers. We previously demonstrated the validity of this approach for studying ageing in humans; here, we illustrate its broad potential for ecological studies. 3. As an example, we used biomarker data on shorebirds and found that birds with an abnormal condition had a lower maximal thermogenic capacity and higher scores of inflammation, with important implications for their ecology and health. Moreover, Mahalanobis distance captured a signal of condition not detected by the...

1. 野生自由活动动物的身体状况会影响其应激反应、决策行为、满足关键生存需求的能力，并最终影响其适合度（fitness）。然而，生态学中的这一关键属性仍难以评估，且亟需采用比常见单变量替代指标（univariate proxies）更具整合性的测量方法。
2. 我们提出了一种系统生物学方法（systems biology approach），该方法基于由生理生物标志物（physiological biomarkers）计算得到的马氏距离（Mahalanobis distance），将个体沿着“正常/最优”至“异常/次优”的生理状态梯度进行定位。我们此前已验证了该方法用于人类衰老研究的有效性；在此，我们将阐明其在生态学研究中的广泛应用潜力。
3. 作为示例，我们使用了滨鸟（shorebirds）的生物标志物数据，结果发现身体状况异常的个体具有更低的最大产热能力，同时炎症评分更高，这对其生态学特征与健康具有重要意义。此外，马氏距离捕捉到了未被检测到的与状况相关的信号（原文此处未完整收尾）。