Data from: Physiological responses to elevated temperature across the geographic range of a terrestrial salamander

Widespread species often possess physiological mechanisms for coping with thermal heterogeneity, and uncovering these mechanisms provides insight into species responses to climate change. The emergence of non-invasive corticosterone (CORT) assays allows us to rapidly assess physiological responses to environmental change on a large scale. We lack, however, a basic understanding of how temperature affects CORT, and whether temperature and CORT interactively affect performance. Here, we examine the effects of elevated temperature on CORT and whole-organism performance in a terrestrial salamander, Plethodon cinereus, across a latitudinal gradient. Using water-borne hormone assays, we found that raising ambient temperature from 15 to 25&[deg]C increased CORT release at a similar rate for salamanders from all sites. However, CORT release rate was higher overall in the warmest, southernmost site. Elevated temperatures also affected physiological performance, but the effects differed among sites. Ingestion rate increased in salamanders from the warmer sites but remained the same for those from cooler sites. Mass gain was reduced for most individuals, though this reduction was more dramatic in salamanders from the cooler sites. We also found a temperature-dependent relationship between CORT and food conversion efficiency (i.e., the amount of mass gained per unit food ingested). CORT was negatively related to food conversion efficiency at 25&[deg]C but was unrelated at 15&[deg]C. Thus, the energetic gains of elevated ingestion rates may be counteracted by elevated CORT release rates experienced by salamanders in warmer environments. By integrating multiple physiological metrics, we highlight the complex relationships between temperature and individual responses to warming climates.

广布物种通常具备应对热异质性的生理机制，揭示此类机制有助于深入理解物种对气候变化的响应。无创皮质酮（corticosterone, CORT）检测技术的出现，使我们能够大规模快速评估生物对环境变化的生理响应。然而我们仍缺乏对温度如何影响皮质酮水平，以及温度与皮质酮是否会交互影响个体生理表现的基础认知。本研究以沿纬度梯度分布的陆栖蝾螈红背蝾螈（Plethodon cinereus）为研究对象，探究升温对其皮质酮水平及整体个体性能的影响。通过水体激素检测法，我们发现当环境温度从15℃升高至25℃时，所有采样位点蝾螈的皮质酮释放速率均以相似幅度上升。但整体而言，来自最温暖的最南部采样位点的蝾螈皮质酮释放速率更高。升温同样会影响蝾螈的生理性能，但不同采样位点的响应存在差异。来自温暖位点的蝾螈摄食率有所提升，而来自凉爽位点的个体摄食率则无明显变化。多数个体的体重增长受到抑制，且这种抑制在凉爽位点来源的蝾螈中表现得更为显著。我们还发现皮质酮与食物转化效率（即单位摄食食物对应的体重增益量）之间的关联依赖于环境温度。在25℃环境下，皮质酮水平与食物转化效率呈负相关；而在15℃环境下二者则无显著关联。因此，温暖环境中蝾螈因摄食率提升带来的能量收益，可能会被其升高的皮质酮释放速率所抵消。本研究通过整合多项生理指标，揭示了温度与个体对气候变暖的响应之间存在复杂关联。