Slowly reproducing and long-lived terrestrial mammals are often more at risk from challenges that influence fitness and survival. It is, therefore, important to understand how animals cope with such challenges and how coping mechanisms translate over generations and affect phenotypic plasticity. Rapidly escalating anthropogenic challenges may further diminish an animal’s ability to reinstate homeostasis. Research to advance insights on elephant stress physiology has predominantly focused on relative or comparative analyses of a major stress response marker, glucocorticoids (GCs), across different ecological, anthropogenic, and reproductive contexts. This paper presents an extensive review of published findings on Asian and African elephants from 1980 to 2023 (May) and reveals that stress responses, as measured by alterations in GCs in different sample matrices, often are highly dynamic and vary within and across individuals exposed to similar stimuli, and not always in a predictable fashion. Such dynamicity in physiological reactivity may be mediated by individual differences in personality traits or coping styles, ecological conditions, and technical factors that often are not considered in study designs. We describe probable causations under the ‘Physiological Dynamicity Model’, which considers context–experience–individuality effects. Highly variable adrenal responses may affect physiological plasticity with potential fitness and survival consequences. This review also addresses the significance of cautious interpretations of GCs data in the context of normal adaptive stress versus distress. We emphasize the need for long-term assessments of GCs that incorporate multiple markers of ‘stress’ and ‘well-being’ to decipher the probable fitness consequences of highly dynamic physiological adrenal responses in elephants. Ultimately, we propose that assessing GC responses to current and future challenges is one of the most valuable and informative conservation tools we have for guiding conservation strategies.

中文翻译：

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大象的生理可塑性：非洲和亚洲象的高动态糖皮质激素

繁殖缓慢且寿命较长的陆生哺乳动物往往更容易受到影响健康和生存的挑战的影响。因此，了解动物如何应对这些挑战以及应对机制如何在几代人中转化并影响表型可塑性非常重要。快速升级的人为挑战可能会进一步削弱动物恢复体内平衡的能力。深入了解大象应激生理学的研究主要集中在不同生态、人为和生殖背景下主要应激反应标志物糖皮质激素（GC）的相对或比较分析。本文对 1980 年至 2023 年（5 月）期间已发表的亚洲象和非洲象研究结果进行了广泛回顾，并揭示了通过不同样本基质中 GC 的变化来衡量的应激反应通​​常是高度动态的，并且在暴露于环境的个体内部和个体之间存在差异。类似的刺激，而且并不总是以可预测的方式。生理反应的这种动态性可能是由人格特征或应对方式、生态条件和技术因素的个体差异介导的，而这些因素在研究设计中通常没有考虑到。我们在“生理动态模型”下描述了可能的因果关系，该模型考虑了背景-经验-个性效应。高度可变的肾上腺反应可能会影响生理可塑性，从而产生潜在的健康和生存后果。这篇综述还讨论了在正常适应性压力与痛苦的背景下谨慎解释 GC 数据的重要性。我们强调需要对GC进行长期评估，其中包含“压力”和“幸福”的多种标记，以破译大象高度动态的生理肾上腺反应可能产生的健康后果。最终，我们建议评估GC对当前和未来挑战的反应是我们指导保护策略的最有价值和信息最丰富的保护工具之一。