Van Damme Raoul, Bauwens Dirk, Castilla Aurora M, Verheyen Rudolf F
Field Biological Station, University of Antwerp (U.I.A.), Verbindingsweg, B-2180, Kalmthout, Belgium.
Department of Biology, University of Antwerp (U.I.A.), Universiteitsplein 1, B-2610, Wilrijk, Belgium.
Oecologia. 1989 Sep;80(4):516-524. doi: 10.1007/BF00380076.
We studied, in the field and laboratory, aspects of the thermal biology in two populations of the lizard Podarcis tiliguerta along a 1450 m altitudinal gradient. Body temperatures (T) at high altitudes average lower, are more variable, but are more elevated above environmental temperatures than at sea level. Lizards partially reduced the impact of altitudinal changes in thermal loads through presumable subtle behavioural adjustments. A comparison of the thermal preferences in the laboratory, the maximal operative temperatures predicted from a biophysical model, and the activity T's at both sites, indicates that the main response to changing environmental conditions is an active shift in thermoregulatory set points. Integration of field T's and laboratory data on temperature specific sprint speeds, predicts that the mountainous lizards experience reduced running abilities that are especially acute in the early morning. Despite this impairment of running performance, the thermal sensitivity of running speed has not evolved to match the T's experienced by both populations. This result supports the view that the thermal physiology of this lizard is evolutionarily conservative, but the lack of information on the relation between running performance and fitness components impedes rejection of alternative hypotheses.
我们在野外和实验室中，对沿1450米海拔梯度分布的两个意大利壁蜥种群的热生物学方面进行了研究。高海拔地区的体温平均较低，变化更大，但比海平面地区更高于环境温度。蜥蜴通过可能的细微行为调整，部分减轻了热负荷中海拔变化的影响。对实验室中的热偏好、根据生物物理模型预测的最高有效温度以及两个地点的活动体温进行比较，结果表明，对不断变化的环境条件的主要反应是体温调节设定点的主动转变。结合野外体温和关于温度特定冲刺速度的实验室数据预测，山区蜥蜴的奔跑能力下降，在清晨尤为明显。尽管奔跑性能受到这种损害，但奔跑速度的热敏感性并未进化到与两个种群所经历的体温相匹配。这一结果支持了这样一种观点，即这种蜥蜴的热生理学在进化上是保守的，但由于缺乏关于奔跑性能与适合度成分之间关系的信息，阻碍了对其他假设的否定。
