Centre for Behavioural and Physiological Ecology, Zoology, University of New England, Armidale NSW 2351, Australia.
Integr Comp Biol. 2011 Sep;51(3):337-48. doi: 10.1093/icb/icr042. Epub 2011 Jun 22.
Torpor, the most effective means of energy conservation available to endotherms, is still widely viewed as a specific adaptation in a few high-latitude, cold-climate endotherms with no adaptive function in warm regions. Nevertheless, a growing number of diverse terrestrial mammals and birds from low latitudes (0-30°), including species from tropical and subtropical regions, are heterothermic and employ torpor. Use of torpor is especially important for bats because they are small, expend large amounts of energy when active, rely on a fluctuating food supply, and have only a limited capacity for storage of fat. Patterns of torpor in tropical/subtropical bats are highly variable, but short bouts of torpor with relatively high body temperatures (T(b)) are most common. Hibernation (a sequence of multiday bouts of torpor) has been reported for free-ranging subtropical tree-dwelling vespertilionids, cave-dwelling hipposiderids, and house-dwelling molossids. The observed range of minimum T(b) is ∼6-30 °C, and the reduction of energy expenditure through the use of torpor, in comparison to normothermic values, ranges from 50 to 99%. Overall, torpor in the tropics/subtropics has been reported for 10 out of the currently recognized 18 bat families, which contain 1079 species, or 96.7% of all bats. Although it is unlikely that all of these are heterothermic, the large majority probably will be. Frequent use of torpor, including hibernation in diverse groups of tropical/subtropical bats, suggests that heterothermy is an ancestral chiropteran trait. Although data especially from the field are still scarce, it is likely that torpor, highly effective in reducing requirements for energy and water even under warm conditions, plays a crucial role in the long-term survival of the majority of small tropical and subtropical bats. Discovering how bats achieve this provides numerous opportunities for exiting new research.
蛰伏，作为一种内温动物最有效的节能方式，仍被广泛认为是少数高纬度、寒冷气候的内温动物的特殊适应，而在温暖地区没有适应功能。然而，越来越多来自低纬度（0-30°）的不同陆地哺乳动物和鸟类，包括来自热带和亚热带地区的物种，都是异温动物，并采用蛰伏。蛰伏对于蝙蝠尤为重要，因为它们体型小，活跃时消耗大量能量，依赖波动的食物供应，且脂肪储存能力有限。热带/亚热带蝙蝠的蛰伏模式变化多样，但最常见的是短暂的蛰伏和相对较高的体温（T(b)）。自由生活的亚热带树栖蝙蝠、洞穴栖居的蹄蝠和居家栖居的食虫蝙蝠都有报道过冬眠（一连串多天的蛰伏）。观察到的最低 T(b)范围为 6-30°C，与正常体温相比，通过蛰伏降低的能量消耗范围为 50-99%。总体而言，在目前已识别的 18 种蝙蝠科中，有 10 种（占所有蝙蝠的 96.7%）在热带/亚热带地区有蛰伏记录。虽然不太可能所有这些都是异温动物，但绝大多数可能是。频繁使用蛰伏，包括热带/亚热带蝙蝠的不同群体的冬眠，表明异温性是一种古老的翼手目特征。尽管特别是来自野外的数据仍然很少，但蛰伏在降低对能量和水的需求方面非常有效，即使在温暖的条件下，它也可能在大多数小型热带和亚热带蝙蝠的长期生存中发挥关键作用。发现蝙蝠如何实现这一点为新的研究提供了许多机会。
