一些蝙蝠会在细雨中飞行，然而一旦遇到暴雨，它们便会找地方躲起来。
在5月3日的《生物学快报》网络版上刊登的一项新的研究给出了一个答案：当蝙蝠的皮毛和翅膀被打湿后，它们不得不更加卖力地飞行。
在哥斯达黎加进行的一连串试验中，科学家对在一个八角形大笼子中飞行的索维尔短尾果幅进行了研究。
有时他们会用自来水把蝙蝠弄湿；有时蝙蝠会被雨水打湿。研究小组发现，与外表干燥时相比，蝙蝠被打湿后使用的能量是前者的两倍。
在雨中飞行并没有什么区别，这排除了因雨点击打翅膀，或水的实际重量而产生的一些力学问题。
科学家认为，就像大多数潮湿的哺乳动物那样，潮湿的蝙蝠会很冷，因此它们不得不努力保持体温。并且随着雨水弄乱它们的皮毛、打湿它们的翅膀，浑身湿透的蝙蝠可能也无法运用空气动力。（生物谷Bioon.com）
生物谷推荐原文出处：
Biology Letters DOI： 10.1098/rsbl.2011.0313
Rain increases the energy cost of bat flight
Voigt, Christian C.; Schneeberger, Karin; Voigt-Heucke, Silke L.; Lewanzik, Daniel
Similar to insects, birds and pterosaurs, bats have evolved powered flight. But in contrast to other flying taxa, only batsare furry. Here, we asked whether flight is impaired when bat pelage and wing membranes get wet. We studied the metabolismof short flights in Carollia sowelli, a bat that is exposed to heavy and frequent rainfall in neotropical rainforests. We expected bats to encounter higher thermoregulatorycosts, or to suffer from lowered aerodynamic properties when pelage and wing membranes catch moisture. Therefore, we predictedthat wet bats face higher flight costs than dry ones. We quantified the flight metabolism in three treatments: dry bats, wetbats and no rain, wet bats and rain. Dry bats showed metabolic rates predicted by allometry. However, flight metabolism increasedtwofold when bats were wet, or when they were additionally exposed to rain. We conclude that bats may not avoid rain onlybecause of sensory constraints imposed by raindrops on echolocation, but also because of energetic constraints.
