Exercise-Generated Heat Contributes to Thermoregulation by Gambel's Quail in the Cold
Exercise-Generated Heat Contributes to Thermoregulation by Gambel's Quail in the Cold
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运动产生的热量有助于甘贝尔鹌鹑在寒冷中的体温调节
DOI：
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发表时间：
1992
期刊：
影响因子：
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通讯作者：
G. Walsberg
中科院分区：
文献类型：
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作者：
E. Zerba;G. Walsberg
本研究的目的是探讨冷暴露时运动产生的热量分配与静息代谢产热之间的关系。我们测试了这样一个假设，即在寒冷暴露期间，运动产生的热量有助于实现恒温需求。我们的假设是，由于边界和羽毛绝缘层的破坏，运动时的恒温要求高于静止空气中休息的鸟类。我们预测，在适度运动时，运动鸟类的代谢热产量将高于静止空气中休息鸟类的代谢热产量，但与暴露于类似对流条件下休息鸟类的代谢热产量没有显著差异。为了验证我们的假设，我们测量了甘贝尔鹌鹑（Callipepla gambelii Gambel）在圆形代谢室中奔跑和静止空气中休息时的全动物耗氧量，环境温度低于动物的较低临界温度。我们将这些数据与之前甘贝尔鹌鹑的数据进行了比较，这些数据暴露在风速等于我们实验中使用的跑步速度的风中。除了耗氧量测量，我们还测量了运动和休息鸟类的体温。数据支持了我们的假设和预测。(1)运动鸟类的全身热阻低于静止空气中静止鸟类的全身热阻，说明运动鸟类由于边界和羽毛保温层的破坏，对恒温的要求更高。(2)运动鸟类的发热量显著高于静止空气中休息鸟类的发热量，但与相同对流条件下休息鸟类的发热量差异不显著。(3)静息和运动鸟类的体温差异不显著。然而，运动鸟类的平均体温比暴露在风中的休息鸟类高2°C。我们得出的结论是，与不活动的动物暴露于类似的对流环境相比，运动动物在低环境温度下可能不会产生与运动活动相关的能量消耗。
Summary The purpose of this study was to investigate the relationship between the allocation of exercise-generated heat and resting metabolic heat production during cold exposure. We tested the hypothesis that, during cold exposure, exercise-generated heat contributes to the fulfillment of the thermostatic requirement. Our assumption was that the thermostatic requirement is higher for exercising than for resting birds in still air because of the disruption of boundary and plumage insulation layers. We predicted that, during moderate exercise, the metabolic heat production of exercising birds would be higher than that for resting birds in still air but would not differ significantly from the metabolic heat generated by resting birds exposed to similar convective conditions. To test our hypothesis we measured whole-animal oxygen consumption of Gambel's quail (Callipepla gambelii Gambel) running in a circular metabolic chamber and at rest in still air at ambient temperatures below the animal's lower critical temperature. We compared these data to previous data for Gambel's quail at rest exposed to wind at a speed equal to the running speed used in our experiments. In addition to oxygen consumption measurements, we measured body temperatures of exercising and resting birds. The data supported our assumption and predictions. (1) Whole-body thermal resistance for exercising birds was lower than that for resting birds in still air, indicating that the thermostatic requirement was higher for exercising birds because of the disruption of boundary and plumage insulation layers. (2) Heat productions of exercising birds were significantly higher than those of resting birds in still air but were not significantly different from the heat productions of resting birds exposed to similar convective conditions. (3) Body temperatures were not significantly different between resting birds in still air and exercising birds. The mean body temperature of exercising birds, however, was 2°C higher than that of resting birds exposed to wind. We concluded that an exercising animal probably does not incur an energetic cost associated with locomotor activity at low ambient temperatures in comparison to an inactive animal exposed to a similar convective regime.