Wildlife Biology Program, The University of Montana, 32 Campus Drive, Missoula, MT 59812, USA.
J Exp Biol. 2013 Jun 1;216(Pt 11):1982-90. doi: 10.1242/jeb.081067.
Severe storms can pose a grave challenge to the temperature and energy homeostasis of small endothermic vertebrates. Storms are accompanied by lower temperatures and wind, increasing metabolic expenditure, and can inhibit foraging, thereby limiting energy intake. To avoid these potential problems, most endotherms have mechanisms for offsetting the energetic risks posed by storms. One possibility is to use cues to predict oncoming storms and to alter physiology and behavior in ways that make survival more likely. Barometric pressure declines predictably before inclement weather, and several lines of evidence indicate that animals alter behavior based on changes in ambient pressure. Here we examined the effects of declining barometric pressure on physiology and behavior in the white-crowned sparrow, Zonotrichia leucophrys. Using field data from a long-term study, we first evaluated the relationship between barometric pressure, storms and stress physiology in free-living white-crowned sparrows. We then manipulated barometric pressure experimentally in the laboratory and determined how it affects activity, food intake, metabolic rates and stress physiology. The field data showed declining barometric pressure in the 12-24 h preceding snowstorms, but we found no relationship between barometric pressure and stress physiology. The laboratory study showed that declining barometric pressure stimulated food intake, but had no effect on metabolic rate or stress physiology. These data suggest that white-crowned sparrows can sense and respond to declining barometric pressure, and we propose that such an ability may be common in wild vertebrates, especially small ones for whom individual storms can be life-threatening events.
剧烈的风暴会给小型内温动物的体温和能量平衡带来严重挑战。风暴伴随着较低的温度和大风，增加了代谢支出，并可能抑制觅食，从而限制能量摄入。为了避免这些潜在问题，大多数恒温动物都有抵消风暴带来的能量风险的机制。一种可能性是利用线索来预测即将到来的风暴，并改变生理和行为，使其更有可能生存。气压在恶劣天气来临前可预测性下降，有几条证据表明，动物会根据环境压力的变化改变行为。在这里，我们研究了气压下降对白冠麻雀（Zonotrichia leucophrys）生理和行为的影响。利用长期研究的现场数据，我们首先评估了气压、风暴和自由生活的白冠麻雀应激生理之间的关系。然后，我们在实验室中进行了气压实验操作，确定了气压变化如何影响活动、食物摄入、代谢率和应激生理。现场数据显示，在暴风雪前 12-24 小时内气压下降，但我们没有发现气压与应激生理之间的关系。实验室研究表明，气压下降会刺激食物摄入，但对代谢率或应激生理没有影响。这些数据表明，白冠麻雀能够感知和应对气压下降，我们提出这种能力可能在野生脊椎动物中很常见，尤其是对于个体风暴可能危及生命的小型动物。
