Centre for Behavioural and Physiological Ecology, Zoology, University of New England, Armidale, New South Wales 2351, Australia.
Biol Lett. 2012 Oct 23;8(5):868-70. doi: 10.1098/rsbl.2012.0269. Epub 2012 Jun 6.
Mammalian torpor saves enormous amounts of energy, but a widely assumed cost of torpor is immobility and therefore vulnerability to predators. Contrary to this assumption, some small marsupial mammals in the wild move while torpid at low body temperatures to basking sites, thereby minimizing energy expenditure during arousal. Hence, we quantified how mammalian locomotor performance is affected by body temperature. The three small marsupial species tested, known to use torpor and basking in the wild, could move while torpid at body temperatures as low as 14.8-17.9°C. Speed was a sigmoid function of body temperature, but body temperature effects on running speed were greater than those in an ectothermic lizard used for comparison. We provide the first quantitative data of movement at low body temperature in mammals, which have survival implications for wild heterothermic mammals, as directional movement at low body temperature permits both basking and predator avoidance.
哺乳动物的蛰伏能节省大量能量，但蛰伏通常被认为会导致动物无法行动，从而更容易受到捕食者的攻击。然而，与这一假设相反，一些野生的小型有袋类哺乳动物在体温较低时会移动到晒暖地点进行蛰伏，从而在苏醒时将能量消耗降到最低。因此，我们量化了哺乳动物的运动性能如何受到体温的影响。在所测试的三种已知在野外使用蛰伏和晒暖的小型有袋类物种中，它们可以在体温低至 14.8-17.9°C 时蛰伏并移动。速度是体温的一个 S 型函数，但与用于比较的外温动物蜥蜴相比，体温对奔跑速度的影响更大。我们提供了哺乳动物在低温下运动的第一个定量数据，这对野生异温动物哺乳动物具有生存意义，因为在低温下的定向运动既能晒暖又能躲避捕食者。
