温州地区冬季北红尾鸲的代谢特征及体温调节

为探讨北方迁徙性鸟类北红尾鸲(Phoenicurus auroreus)在越冬环境的代谢特征及体温调节,本文采用开放式氧气分析仪和数字式温度测量仪测定了在环境温度(Ta) 5、10、15、20、25、27.5、30、32.5、35、37.5、40℃条件下的代谢率(MR)和体温(Tb),并计算不同温度的热传导(C)。结果表明:在Ta为5~35℃范围内,北红尾鸲的Tb基本维持恒定,平均为40.3±0.1℃;热中性区(TNZ)为25~35℃;基础代谢率(BMR)为50.25±1.35 mL O2·h^-1,是Londo1o等(2015)体重预期值的151%;在Ta为5~25℃范围内,MR随Ta的降低而显著增加,回归方程为:MR (m L O2·h^-1)=99.65-1.93Ta(r=-0.707,P<0.001);高于35℃时,MR随Ta升高增加;当Ta为40℃时,MR达到59.78±1.31 mL O2·h^-1;在Ta为5~25℃范围内,北红尾鸲的C最低且基本保持恒定,为0.17±0.01 mL O2·g^-1·h^-1·℃^-1,是Aschoff(1981)体重预测值的111%;北红尾鸲的基本热生物学特征为较高的Tb、BMR和C以及较宽的TNZ,具有北方地区小型鸟类的代谢特点。

Metabolism and thermoregulation of Daurian redstarts( Phoenicurus auroreus) in Wenzhou in winter

Basal metabolic rate (BMR) is a key hub in the network of physiological mechanisms connecting life history traits.To understand the ecophysiological characteristics of migrator,we examined the physiological responses of Daurian redstart (Phoenicurus auroreus) to changes in temperature by measuring their body temperature (Tb) and metabolic rate (MR),and calculating thermal conductance (C) at temperatures (Ta) between 5℃and 40℃.Ten Daurian redstarts (males) were used in this experiment,with an average body mass of 17.6±2.0 g.Food and water were supplied ad libitum.Oxygen consumption of birds was measured using an open-circuit respirometry system (TSE Instruments,Germany).Tbwas measured during metabolic measurements using a lubricated thermocouple inserted in the cloaca,and the output was digitized using an Oakton thermocouple meter (Eutech Instruments,Singapore).C (m L O2g^-1·h^-1·℃^-1) at any given Tawas calculated from the formula:C=MR/(Tb-Ta).In the range of Tafrom 5 to 35℃,Tbof Daurian redstarts remained constant,with an average of 40.3±0.1℃.The thermal neutral zone (TNZ) of Daurian redstarts was 25-35℃.The mean MR within TNZ (i.e.BMR) of the species was 50.25±1.35 mL O2·^-1,which is 151%of the expected value from their body mass.When Tawas below 25℃,MR increased with the decline of Tawith a fitting equation of MR (mL O2·h^-1)=99.65-1.93Ta(r=-0.707,P<0.001).When Tawas higher than 35℃,MR increased with the increasing Ta,and reached 59.78±1.31 m L O2·h^-1when Tawas 40℃.Average minimum C of redstarts was 0.17 mL O2·g^-1·h^-1·℃-1measured between 5 and 25℃,representing 111%of the expected value based on their body mass.The basic thermobiological characteristics of Daurian redstarts are high Tb,BMR and C,and wide TNZ,which might make them acclimatized to the environment and survive at cold areas.