Abstract: Plateau pika(Ochotona curzoniae)is a dominant species in Kobresia humilis meadow in Alpine Meadow Ecosystem of Qinghai plateau．The evaporative water loss(EW L)， basal and resting metabolism (BMR and RMR) nonshiverlng thermogenesis (NST) were measured，the total thermal conductance (C)，dry conductance,and thermoregulatory index(TI) were calculated and the role of evaporative heat loss in thermoregulation， especilly at high ambient temperature (Ta)of O．curzoniae were discussed． The results obtained mainly are as follows：
1．The thermal neutral zone (TNZ) is about 25-30℃ ． BMR is 1．54 mlO_2/g·h,
42% higher to that predicted by Kleiber(1961)．Below TNZ their isa inversly relat
ionship between RMR and Ta， which can be described as:
RMR(m1 O₂/g·h)=4．6909－0．1115Ta
while the metabolism increased significantly above 30℃ ， reach to 3.29ml O₂/g·h ，and the pikas will be die about1h at 95℃ because of the thermaI stress．
2．C of O．curzoniae at different temperatures were calculated according to the Newton' s law， mean value of C below TNZ is 0.152ml O₂/g·h·℃ ， 51% higher to that predicted by Herried et al．(1967)and 42% higher relative to that predicted by Bradly et al． (1980)．
3． EWL is lower below TNZ， increased markedly during and above TNZ．Mean
EWL below TNZ is 1.788 mg／g·h， and reach to peak at 30℃ ， 3.557mg／g·h．The relationship between EWL and Ta in and above TNZ is described as:
EWL(mg／g·h)= -3.096+0.210Ta
4．The contribution of EWL to total thermal conductance is 13% below TNZ,
18.0% in TNZ and 15% above TNZ．The variation pattern of dry C is similar as that
of total thermal conductance．The ratio of EWL to metabolic rate (MR) is the
function of Ta， increasing with Ta．The regression equation within 15～ 30℃ is：
EWL／MR =-1.266+0.102Ta 5．Body temperature (Tb) is nearly contant beloW 27．5℃ ， mean 37．5⁰C， independent to Ta,but increasing with Ta above 27．5℃ ．The equation is
Tb(℃ )=24．75+0．454Ta
6．The response of O．curzoniae to noradrenaline is very strong． Maximum NST is 4．34 ml O_2/g·h ，NST scope (NST／BMR)is 2．82 and NST capacity (NST- BMR)is 2．80 ml O_2/g·h ，Tb of pikas increased 1．8℃ after noradranaline injection．
7．The maximum thermal conductance (C_max ) is 0．8323 ml O_2/g·h·℃ ， while dry C is 0．6909 ml O_2/g·h·℃ ， Evaporative C is 0．1414ml O₂／g．h·℃ (about 17 C_max )，The ratio of maximum C to minimum C is 5 49%．The thermoregulatory index (TI) is 15．40， while physical thermoregulatory index is 5．49 and chemical thermoregulatory index is 2．80．
Our results indicated that O．curzoniae is a species that well adapt to the cold and high altitude region．The thermoregulatory characteristics Of O．curzoniae such as high BMR level，relative low Tb and high NST，limiting thermoregulatory ability to high Ta suggest that the main stress of O．curzoniaefaced in the environment that they lived is cold．From the evolutionary scale，O．curzoniaeadapt the environment mainly by increasing thermogenesis capacity， and incorporating the anatomical and behavioral mechanisms．

Key words: Plateau pika, Ochotona curzoniae, Evaporative water loss, EWL, Basal metabolic rate, BMR, Thermal conductance, C, Nonshivering thermogenesis, NST, Thermoregulation．

摘要： 本文对高原鼠兔(Ochotona curzoniae)的静止代谢率(RMR)、蒸发失承(EWL)、非颤抖性产热(NST)等能学参数进行了测定，计算了干燥热传导(dry C)、 热能调节热标(TI)等，评估了蒸发散热(EHL)在热传导(C)中的地位，结果表明:高原鼠兔的基础代谢率(BMR)和最小热传导(C_m)均高于期望值； 25℃以上EHL占有重要地位；热能调节能力较好，但抗高温能力较差；这些特征对于栖居在年气温差较小、日温差大的高寒环境中的高原鼠兔具重要的适应意义。

关键词: 高原鼠兔, 蒸发失水, 基础代谢率, 热传导, 非颤抖性产热, 热能调节