VARIATION IN THERMAL METABOLISM AND BROWN ADIPOSE TISSUE (BAT) IN POSTNATAL DEVELOPMENT OF OCHOTONA CURZONIAE
FENG YONO WANG ZU-WANG(Northwest Plateau Institute of Biology, Academia Sinica, Xining 810001)
This work was carried out at Haibei Alpine Meadow Ecosystem Research Station at Men Yuan, Qinghai Province, from May to September in 1988 and in May, 1989. The results showed that when ambient temperature varied, new-born pikas (Ochotona curzoniae) were not able to maintain steady body temperature because they had only the initial capacity of thermoregu-lation and mainly depended on the nests underground and the developed brown adipose tissue to protect against cold temperature. Both heat insulation and thermogenesis capacity increased with corresponding decline in the importance of BAT during the development of plateau pikas, however, heat insulation has precedence in development over the thermogenesis capacity. When body weights of young pikas reached the level of adults, minimum metabolic rate was higher than the value predicted by Kleiber, and thermal conductance was lower than the value predicted by Bradey-Deavers. In addition plateau pikas complemented physiological regulation through behavioral thermoregulation. Adaptation of plateau pikas to the alpine envinment is discussed in the paper.