Hansen S, Lavigne D M
Department of Zoology, University of Guelph, Ontario, Canada.
Physiol Zool. 1997 Jul-Aug;70(4):436-43. doi: 10.1086/515849.
The metabolic rates of six female grey seal (Halichoerus grypus) pups were measured during their postweaning fast at air temperatures between -15 degrees and 30 degrees C. The composite of their individual thermal neutral zones extended from a mean lower critical temperature of -7.1 degrees +/- 0.7 degree C to a mean upper critical temperature of 23.0 degrees +/- 0.4 degree C. Within the thermal neutral zone, mean standard metabolic rate of the fasting animals was 1,265 +/- 82 kcal d-1, or about 1.1 times the value predicted for an adult animal of similar body mass (mean mass = 40.9 +/- 1.2 kg). For those grey seal populations that reproduce during winter months in the eastern and western Atlantic and in the Baltic Sea, the lower critical temperature of fasting pups corresponds closely with the coldest mean monthly air temperature at the northern end of their breeding ranges. This observation supports the hypothesis that cold ambient air temperatures limit the northern breeding distribution of grey seals, primarily through their thermoregulatory effects on small, fasting pups before they enter the water.
在-15摄氏度至30摄氏度的气温下，测量了六只雌性灰海豹幼崽断奶后禁食期间的代谢率。它们个体热中性区的综合范围从平均下限临界温度-7.1摄氏度±0.7摄氏度延伸至平均上限临界温度23.0摄氏度±0.4摄氏度。在热中性区内，禁食动物的平均标准代谢率为1265±82千卡/天，约为预测的类似体重成年动物（平均体重=40.9±1.2千克）代谢率值的1.1倍。对于那些在东大西洋、西大西洋和波罗的海冬季繁殖的灰海豹种群，禁食幼崽的下限临界温度与它们繁殖范围北端最冷月的平均气温密切相关。这一观察结果支持了以下假设：寒冷的环境空气温度限制了灰海豹在北方的繁殖分布主要是通过对小的、禁食的幼崽进入水中之前的体温调节作用。
