Title: Metabolic rate, maximum metabolism, and advantages of torpor in the fat mouse Steatomys pratensis natalensis Roberts, 1921 (Dendeomurinae)
Abstract: The fat mouse Steatomys pratensis natalensis (mean body mass 37.4±0.43 (se)) has a low euthermic body temperature Tb=30.1–33.8 °C and a low basal metabolic rate (BMR)=0.50 ml O2 g−1 h−1. Below an ambient temperature (Ta)=15 °C, the mice were hypothermic. The lowest survivable Ta=10 °C. Torpor is efficient in conserving energy between Ta=15–30 °C, below Ta=15 °C, the mice arouse. Euthermic and torpid mice were hyperthermic at Ta=35 °C. Thermal conductance was 0.159 ml O2 g−1 h−1 °C−1, 98.8% of the expected value. Non-shivering thermogenesis (NST) was 2.196 ml O2 g−1 h−1 (3.69×BMR). Maximal oxygen consumption, however, was 3.83 ml O2 g−1 h−1 (6.44×BMR), indicating that other methods of heat production are additive. Because fat mice conserve energy by torpor only between Ta=15–30 °C, we suggest that torpor may be a more important mechanism for surviving food shortages than for surviving cold weather.
Publication Year: 2005
Publication Date: 2005-12-01
Language: en
Type: article
Indexed In: ['crossref']
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Cited By Count: 8
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