Department of Environment and Agriculture, Curtin University, PO Box U1987 Perth, Western Australia 6845, Australia.
Comp Biochem Physiol A Mol Integr Physiol. 2012 Nov;163(3-4):336-42. doi: 10.1016/j.cbpa.2012.07.011. Epub 2012 Jul 31.
We examine here the thermal physiology of the ash-grey mouse, as there is a paucity of data to explain how Australian rodents meet thermoregulatory demands. Most ash-grey mice remained normothermic over a range of ambient temperatures (10 °C to 30 °C), although they became hyperthermic at high ambient temperatures. One individual entered torpor at ambient temperatures of 20 °C and 25 °C, with minimal body temperatures of 24.5 °C and 28.4 °C respectively, before spontaneously arousing. This is the first evidence of torpor use by an Australian murine rodent. Our data suggest that although ash-grey mice have the physiological ability to use torpor, it is used rarely, presumably due to other behavioural and physiological adaptations. Their higher-than-expected basal metabolic rate (1.56±0.25 mL O(2)g(-1) h(-1)) indicates that ash-grey mice do not have a frugal approach to energy expenditure. Other standard physiological variables were typical of a generalised rodent. A readily-available omnivorous diet, nocturnal activity, semi-fossorial habit and social behaviour presumably allow a high energy lifestyle. A reluctance to use torpor, despite an apparent physiological ability to do so, supports the idea that the use of torpor reflects a net balance between the costs and benefits of a heterothermic thermoregulatory strategy.
我们在这里研究灰鼠的热生理学，因为目前的数据很少能解释澳大利亚啮齿动物如何满足体温调节的需求。大多数灰鼠在环境温度（10°C 到 30°C）范围内保持正常体温，但在高温环境下会出现体温过高。有一只灰鼠在环境温度为 20°C 和 25°C 时进入了蛰伏状态，其体温分别降至 24.5°C 和 28.4°C，然后自动醒来。这是首例澳大利亚鼠类啮齿动物使用蛰伏的证据。我们的数据表明，尽管灰鼠具有使用蛰伏的生理能力，但它们很少使用这种方法，大概是因为它们有其他行为和生理上的适应。它们高于预期的基础代谢率（1.56±0.25 mL O(2)g(-1) h(-1)）表明，灰鼠在能量消耗方面并不是俭省的。其他标准生理变量是典型的通用啮齿动物。容易获得的杂食性饮食、夜间活动、半穴居习性和社会行为，大概允许它们过着高能量的生活方式。尽管灰鼠显然有能力进行蛰伏，但它们不愿意使用这种方法，这支持了这样一种观点，即蛰伏的使用反映了异温调节策略的成本和收益之间的净平衡。
