Grupo de Morfología y Ecología Evolutiva, Instituto de Ciencias Naturales, Universidad Nacional de Colombia, Apartado 7495, Bogotá, D.C, Colombia.
Grupo de Morfología y Ecología Evolutiva, Instituto de Ciencias Naturales, Universidad Nacional de Colombia, Apartado 7495, Bogotá, D.C, Colombia.
J Therm Biol. 2020 Apr;89:102498. doi: 10.1016/j.jtherbio.2019.102498. Epub 2019 Dec 28.
Vertebrate ectotherms may deal with changes of environmental temperatures by behavioral and/or physiological mechanisms. Reptiles inhabiting tropical highlands face extreme fluctuating daily temperatures, and extreme values and intervals of fluctuations vary with altitude. Anolis heterodermus occurs between 1800 m to 3750 m elevation in the tropical Andes, and is the Anolis species found at the highest altitude known. We evaluated which strategies populations from elevations of 2200 m, 2650 m and 3400 m use to cope with environmental temperatures. We measured body, preferred, critical maximum and minimum temperatures, and sprint speed at different body temperatures of individuals, as well as operative temperatures. Anolis heterodermus exhibits behavioral adjustments in response to changes in environmental temperatures across altitudes. Likewise, physiological traits exhibit intrapopulation variations, but they are similar among populations, tended to the "static" side of the evolution of thermal traits spectrum. The thermoregulatory behavioral strategy in this species is extremely plastic, and lizards adjust even to fluctuating environmental conditions from day to day. Unlike other Anolis species, at low thermal quality of the habitat, lizards are thermoconformers, particularly at the highest altitudes, where cloudy days can intensify this strategy even more. Our study reveals that the pattern of strategies for dealing with thermal ambient variations and their relation to extinction risks in the tropics that are caused by global warming is perhaps more complex for lizards than previously thought.
脊椎动物变温动物可以通过行为和/或生理机制来应对环境温度的变化。生活在热带高原的爬行动物面临着极端波动的日温度，极端值和波动间隔随海拔高度而变化。安诺利科 heterodermus 出现在热带安第斯山脉 1800 米至 3750 米的海拔高度之间，是已知海拔最高的安诺利科物种。我们评估了海拔 2200 米、2650 米和 3400 米的种群使用哪些策略来应对环境温度。我们测量了个体在不同体温下的身体、偏好、临界最大和最小温度以及冲刺速度，以及操作温度。安诺利科 heterodermus 表现出行为调整，以应对不同海拔高度的环境温度变化。同样，生理特征表现出种群内的变异，但在种群之间相似，倾向于热特征谱进化的“静态”一侧。该物种的体温调节行为策略非常灵活，即使是每天的环境条件波动，蜥蜴也会进行调整。与其他安诺利科物种不同，在栖息地热质量较低的情况下，蜥蜴是热适应者，特别是在最高海拔地区，阴天甚至会加剧这种策略。我们的研究表明，处理热带环境温度变化的策略模式及其与全球变暖导致的热带灭绝风险的关系对于蜥蜴来说可能比以前想象的更为复杂。
