Recognizing how climate change will impact populations can aid in making decisions about approaches for conservation of endangered species. The blunt-nosed leopard lizard (Gambelia sila) is a federally endangered species that, despite protection, remains in extremely arid, hot areas and may be at risk of extirpation due to climate change. We collected data on the field-active body temperatures, preferred body temperatures and upper thermal tolerance of G. sila. We then described available thermal habitat using biophysical models, which allowed us to (i) describe patterns in lizard body temperatures, microhabitat temperatures and lizard microhabitat use; (ii) quantify the lizards’ thermoregulatory accuracy; (iii) calculate the number of hours they are currently thermally restricted in microhabitat use; (iv) project how the number of restricted hours will change in the future as ambient temperatures rise; and (v) assess the importance of giant kangaroo rat burrows and shade-providing shrubs in the current and projected future thermal ecology of G. sila. Lizards maintained fairly consistent daytime body temperatures over the course of the active season, and use of burrows and shrubs increased as the season progressed and ambient temperatures rose. During the hottest part of the year, lizards shuttled among kangaroo rat burrows, shrubs, and open habitat to maintain body temperatures below their upper thermal tolerance, but, occasionally, higher than their preferred body temperature range. Lizards are restricted from staying in the open habitat for 75% of daylight hours and are forced to seek refuge under shrubs or burrows to avoid surpassing their upper thermal threshold. After applying climatic projections of 1 and 2°C increases to 2018 ambient temperatures, G. sila will lose additional hours of activity time that could compound stressors faced by this population, potentially leading to extirpation.

中文翻译：

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联邦濒临灭绝的豹纹蜥蜴（Gambelia sila）的热生态学

认识到气候变化将如何影响种群，有助于做出有关濒危物种保护方法的决定。钝头豹纹蜥蜴（Gambelia sila）是联邦濒危物种，尽管受到保护，但仍处于极其干旱，炎热的地区，并可能因气候变化而面临灭绝的危险。我们收集了有关田间活动的体温，首选体温和仓鼠的最高耐热性的数据。然后，我们使用生物物理模型描述了可用的热栖息地，这使我们能够（i）描述蜥蜴体温，微生境温度和蜥蜴微生境的使用方式；（ii）量化蜥蜴的体温调节准确性；（iii）计算目前在微型栖息地中受热限制的小时数；（iv）预计将来随着环境温度的升高，限制小时数将如何变化；（v）评估袋鼠大洞穴和提供阴影的灌木在当前和预计的G. sila热生态学中的重要性。在活动季节期间，蜥蜴的白天体温保持相当稳定，随着季节的进行和环境温度的升高，洞穴和灌木的使用量也在增加。在一年中最热的部分，蜥蜴在袋鼠老鼠的洞穴，灌木和开阔的栖息地之间穿梭，以保持体温低于其最高耐热性，但偶尔高于其优选的体温范围。蜥蜴在白天的开放时间中只能在开放的栖息地停留75％，并且被迫在灌木或洞穴下避难，以免超过温度上限。应用1和2°C的气候预测后，温度将升高到2018年的环境温度G. sila 将会失去额外的活动时间，这可能会使该人群面临的压力源更加复杂，并可能导致其绝种。