Data from: Lizards paid a greater opportunity cost to thermoregulate in a less heterogeneous environment

The theory of thermoregulation has developed slowly, hampering efforts to predict how individuals can buffer climate change through behaviour. Mixed results of field and laboratory experiments underscore the need to test hypotheses about thermoregulation explicitly, while measuring costs and benefits in different thermal landscapes.
We simulated body temperature and energy expenditure of a virtual lizard that either thermoregulates optimally or thermoconforms in a landscape of either low or high quality (one or four basking sites, respectively). We then compare the predicted values in each landscape with the observed values for real lizards in experimental arenas.
Lizards thermoregulated more accurately in the high-quality landscape than they did on the low-quality landscape, albeit only slightly so, but spent similar amounts of energy in these landscapes. Basking, rather than shuttling between heat sources, accounted for the majority of the energy consumed in both landscapes.
These results did not support the predictions of our model. In the low-quality landscape, real lizards thermoregulated intensely despite the potential to save energy by thermoconforming. In the high-quality landscape, lizards moved more than expected, suggesting that lizards explored their surroundings despite being able to thermoregulate without doing so.
Our results suggest that non-energetic benefits drive thermoregulatory behaviour in costly environments, despite the missed opportunities arising from thermoregulation. We propose that energetic costs associated with thermoregulatory movement will become substantial in homogeneous environments such as flat plains and dense forests. The theory of thermoregulation should incorporate these aspects if biologists wish to predict responses of ectotherms to changing climates and habitats.

体温调节（thermoregulation）理论的发展进程相对迟缓，掣肘了学界通过生物个体行为预测其如何缓冲气候变化影响的相关研究。野外与实验室实验得到的混杂结果凸显了明确检验体温调节相关假说的必要性，同时需在不同热景观（thermal landscape）中量化体温调节的成本与收益。
本研究模拟了两种策略的虚拟蜥蜴的体温与能量消耗：一类为最优体温调节者，另一类为体温顺应者（thermoconformer）；二者分别栖息于低质量或高质量的热景观中（分别对应仅1个或4个晒太阳位点（basking site））。随后，我们将各热景观中的模型预测值，与实验 arena 中真实蜥蜴的观测数据进行对比。
相较于低质量热景观，真实蜥蜴在高质量热景观中的体温调节精度更高——尽管提升幅度较小，但二者的能量消耗水平相近。在两种热景观中，占能量消耗主体的均为晒太阳行为，而非在热源间穿梭移动。
本研究结果并未支持我们的模型预测。在低质量热景观中，尽管通过体温顺应策略可节省能量，但真实蜥蜴仍进行了高强度的体温调节行为。在高质量热景观中，蜥蜴的移动频率高于模型预期，这表明即便无需移动即可完成体温调节，蜥蜴仍会探索周围环境。
研究结果表明，即便体温调节会错失能量节省的机会，在高成本环境中，非能量收益仍是驱动体温调节行为的主要因素。我们提出，在平坦草原、茂密森林这类均质环境中，与体温调节移动相关的能量成本将变得十分显著。若生物学家希望预测变温动物（ectotherm）对气候变化与栖息地变化的响应，体温调节理论应纳入上述相关要素。