中国四种小型鸟类代谢产热的气候适应

采用封闭式流体压力呼吸计 ,分别在 5 - 35°C、 10 - 30°C和 10 - 35°C的环境温度范围内测定了黄眉(Emberizachrysophrys)、红胁绣眼鸟 (Zosteropserythropleura)、画眉 (Garrulaxcanorus)和红嘴相思鸟 (Leio thrixlutea)的耗氧量、热传导、体温等指标 ,探讨了其代谢产热特征。黄眉、红胁绣眼鸟、画眉和红嘴相思鸟的热中性区分别为 2 5 - 30°C、 2 5 - 2 7 5°C、 2 2 5 - 2 7 5°C和 30 - 32 5°C。在 5 - 30°C的温度范围内 ,黄眉和画眉能保持稳定的体温 ,分别为 4 0 5 8± 0 2 6°C和 4 1 6 8± 0 11°C ;红胁绣眼鸟和红嘴相思鸟的体温随环境温度的降低有下降的趋势。在热中性区内 ,黄眉、红胁绣眼鸟、画眉和红嘴相思鸟的平均基础代谢率分别是3 6 5± 0 14、 4 6 9± 0 2 7、 3 5 5± 0 14和 4 2 4± 0 17mlO2 / (g·h) ,分别是体重预期值的 12 8%、 2 30 %、 6 0 %和 12 0 %。在下临界温度以下 ,黄眉、红胁绣眼鸟、画眉和红嘴相思鸟的最小热传导分别是 0 2 4、 0 31、 0 2 1和 0 34mlO2 / (g·h·°C) ,分别是体重预期值的 14 9%、 14 9%、 2 15 %和 2 4 3%。这些小型鸟类的生理生态学特征是 :(1)黄眉和红胁绣眼鸟有高的基础代谢率和相对低的下临界温度 ,适应低温环境

Climatic adaptations in metabolism of four species of small birds in China

To understand metabolic adaptations,the basal metabolic rate(BMR) of four small birds in China were investigated.Metabolic rate,body temperature and thermal conductance were determined in yellow-browed bunting Emberiza chrysophrys at a temperature range of 5-35° C,chestnut-flanked white-eye Zosterops erythropleura and hwamei Garrulax canorus at 10-30° C,and red-billed leiothrix Leiothrix lutea at 10-35° C.Oxygen consumption was measured by using a closed circuit respirometer.The thermal neutral zone was 25-30° C for yellow-browed bunting,25-27.5° C for chestnut-flanked white-eye,22.5-27.5° C for hwamei,and 30-32.5° C for red-billed leiothrix.With a temperature range of 5-30° C,buntings and hwameis could maintain stable body temperatures (Tb) at a mean of 40.58±0.26° C and 41.68±0.11° C,respectively,and Tbs in white-eyes and leiothrixs tended to decrease with declining ambient temperature.Mean basal metabolic rates within thermal neutral zone were 3.65±0.14 ml O2/(g*h) for buntings,4.69±0.27 ml O2/(g·h) for white-eyes,3.55±0.14 ml O2/(g·h) for hwameis,and 4.24±0.17 ml O2/(g·h) for leiothrix,which are 128%,230%,60% and 120% of the expected value based on their body mass,respectively.Thermal conductance of yellow-browed bunting,chestnut-flanked white-eye,hwamei and red-billed leiothrix were 0.24,0.31,0.21 and 0.34 ml O2/(g·h·° C),respectively,below the lower critical temperature,which were 149%,149%,215%,and 243% of the expected value based on their body mass,respectively.The ecophysiological characteristics of these species were: (1)yellow-browed bunting and chestnut-flanked white-eye had high basal metabolic rates and relatively low lower critical temperatures;these were typical characteristics of adaptations to cold;the two species also showed a relatively higher thermal conductance;this could expand its geographic distribution;(2)hwamei had very low basal metabolic rate and high thermal conductance;because this species feeds mainly on insects,these physiological traits and feeding habits could limit its distribution in a narrow zone where climate is a relative warmer and food resources is abundant;(3)red-billed leiothrix has high basal metabolic rate and high thermal conductance,and relatively high lower critical temperatureActa Zoologica Sinica 51(1):24-30,2005].