Body temperature, evaporative water loss and resting metabolic rate data for 12 southern African arid-zone passerines

Surface water is a critical resource for many birds inhabiting arid regions, but the implications of regular drinking and dependence on surface water for the evolution of thermal physiology remain largely unexplored. We hypothesized that avian thermoregulation in the heat has evolved in tandem with the use of surface water and predicted that a) regularly-drinking species have a greater capacity to elevate rates of evaporative water loss (EWL) compared to non-drinking species, and b) heat tolerance limits are higher among drinking species. To test these predictions, we quantified thermoregulatory responses to high air temperature (Ta) in 13 species of passerines from the South African arid zone and combined these with published values for an additional four species. We categorized each species as either: a) water-dependent, regularly-drinking, or b) water-independent, occasional-/non-drinking. In support of our predictions, both conventional and phylogenetically-independent analyses reve...

地表水对于栖息于干旱区域的多数鸟类而言是关键生存资源，但定期饮水行为与地表水依赖对鸟类热生理演化的潜在影响，目前仍未得到充分探索。我们提出研究假说：鸟类高温环境下的体温调节能力与地表水利用能力协同演化，并做出两项预测：a）与不饮水的鸟类相比，定期饮水物种的蒸发失水（evaporative water loss, EWL）速率提升能力更强；b）饮水物种的耐热极限更高。为验证上述预测，我们对来自南非干旱区域的13种雀形目鸟类开展了高温空气温度（Ta）下的体温调节响应量化实验，并结合另外4个物种的已发表数据进行整合分析。我们将所有受试物种划分为两类：a）依赖水源、定期饮水；b）不依赖水源、偶尔饮水/不饮水。研究结果支持我们的预测，常规分析与系统发育独立分析均显示……