CIBIO, Research Centre in Biodiversity and Genetic Resources, InBIO, Universidade do Porto, Campus de Vairão, Rua Padre Armando Quintas, Vairão, Vila do Conde, Portugal.
Departamento de Biologia, Faculdade de Ciências da Universidade do Porto, R. Campo Alegre, Porto, Portugal.
PLoS One. 2019 Jul 25;14(7):e0220384. doi: 10.1371/journal.pone.0220384. eCollection 2019.
Climate change is negatively affecting many species. The increase in mean air temperature is often associated with shifts in distribution, changes in phenology, and local extinctions. Other factors that only partially correlate with air temperature, like water shortage, may also contribute to the negative consequences of climate change. Although the effect of temperature on lizards' ecophysiology is highly studied, many lizards are also at risks of increased water loss and dehydration, which are predicted to increase under climate change. Here we aimed for the first time to explore if lacertid lizards exposed to dehydration thermoregulate less precisely than hydrated lizards and if dehydrated lizards are less active, change the daily pattern of thermoregulation and balance water balance against thermoregulation. We exposed four lizard species with differences in the thermal preference to thermal gradients with or without a source of water. We measured preferred body temperatures, daily pattern of thermoregulation, and the use of space. Dehydration negatively affected thermoregulation in all investigated species. Dehydrated lizards reduced their preferred body temperature and showed a species-specific pattern of hourly change in thermal preference. Furthermore, they more frequently used the colder parts of the gradients and spent more time hidden. Lizards experiencing dehydration may suffer a reduction in survival and fitness because of poor thermoregulation. Similarly, they may spend more time hidden, waiting for more favourable weather conditions. Such inactivity may carry ecological costs especially in those regions that undergo either short or prolonged periods of droughts.
气候变化正在对许多物种产生负面影响。平均气温的升高通常与分布的转移、物候变化和局部灭绝有关。与气温只有部分相关性的其他因素，如缺水，也可能导致气候变化的负面影响。尽管温度对蜥蜴生态生理学的影响已得到深入研究，但许多蜥蜴也面临着失水和脱水增加的风险，预计在气候变化下这种风险会增加。在这里，我们首次试图探索脱水蜥蜴是否比水合蜥蜴更难以精确调节体温，以及脱水蜥蜴是否不那么活跃、改变日常体温调节模式并在水温和体温调节之间取得平衡。我们将具有不同热偏好的四种蜥蜴暴露在有或没有水源的热梯度中，以测量其偏好的体温、日常体温调节模式和空间利用情况。脱水对所有被研究的物种的体温调节都有负面影响。脱水的蜥蜴降低了它们偏好的体温，并表现出特定于物种的每小时热偏好变化模式。此外，它们更频繁地使用梯度较冷的部分，并花更多的时间隐藏。由于体温调节不良，脱水的蜥蜴可能会减少其存活率和适应性。同样，它们可能会花更多的时间隐藏，等待更有利的天气条件。这种不活跃可能会带来生态成本，尤其是在那些经历短期或长期干旱的地区。
