Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Fundación Miguel Lillo, Miguel Lillo 251, 4000, San Miguel de Tucumán, Argentina; Instituto de Ecología, Comportamiento y Conservación, Fundación Miguel Lillo, Miguel Lillo 251, T4000JFE, San Miguel de Tucumán, Argentina.
Instituto de Ecología, Comportamiento y Conservación, Fundación Miguel Lillo, Miguel Lillo 251, T4000JFE, San Miguel de Tucumán, Argentina.
J Therm Biol. 2021 May;98:102924. doi: 10.1016/j.jtherbio.2021.102924. Epub 2021 Apr 2.
Thermal traits knowledge is elemental to forecasting the impacts of environmental change on lizard diversity. Daily and seasonal environmental temperature fluctuations are amplified in desert and semi-desert species. As ectotherms, they can ameliorate physiological constrains through behavioral thermoregulation. Herein, we explored the thermal biology and behavioral related aspects of the endangered sand lizard Liolaemus scapularis and compared it between austral spring and summer seasons. The study was carried out in a north sector of Medanos de Cafayate in the SW of Salta province, Argentina. Mean field-body temperature (Tb) of L. scapularis was 35.72 °C ranging from 29.10 to 41.10 °C. Regression analyzes showed that substrate temperature (Ts) was the parameter that best explained the variability of the Tb. Body temperature in spring was only positively related to Ts, whereas in summer the Tb was positively related to air temperature (Ta). Despite GLMs indicated that the Tb of L. scapularis result statistically unchanged through seasons sampled and sexes, micro-environmental temperatures were different for males and females between sampled seasons. The behavioral thermoregulation trait assessed, sun exposure, revealed that the use of patches with different sun input varied with temperature parameters and between seasons. This behavioral trait seems to have a crucial role in the thermal strategy of these lizards in order to maintain an optimal homeostatic state avoiding overheating; still the Tb recorded for the studied population places Liolaemus scapularis in the upper range for the genus. Our results suggest that the species is an active thermoregulator with a hit gain through sand conduction mainly, a relevant shuttling behavior and seasonal intraspecific shifts.
热特性知识对于预测环境变化对蜥蜴多样性的影响至关重要。在沙漠和半沙漠物种中，每日和季节性环境温度波动会被放大。作为变温动物，它们可以通过行为体温调节来缓解生理限制。在此，我们探索了濒危沙蜥 Liolaemus scapularis 的热生物学和行为相关方面，并在南半球春季和夏季进行了比较。该研究在阿根廷萨尔塔省西南部 Cafayate 盐沼的北部进行。Liolaemus scapularis 的平均体表温度（Tb）为 35.72°C，范围为 29.10 至 41.10°C。回归分析表明，基质温度（Ts）是解释 Tb 变异性的最佳参数。春季的体温仅与 Ts 呈正相关，而在夏季，Tb 与空气温度（Ta）呈正相关。尽管 GLMs 表明，在所采样的季节和性别中，L. scapularis 的 Tb 统计上没有变化，但在采样季节，雄性和雌性的微环境温度不同。评估的行为体温调节特征，即晒太阳，表明不同太阳输入斑块的使用随温度参数和季节而变化。这种行为特征似乎在这些蜥蜴的热策略中起着至关重要的作用，以维持最佳的体内平衡状态，避免过热；然而，所研究种群的 Tb 记录使 Liolaemus scapularis 处于属的较高范围。我们的研究结果表明，该物种是一种积极的体温调节者，主要通过沙传导获得高收益、相关的穿梭行为和季节性种内转移。
