THE Gila monster cools down in a most unusual way: by using its cloaca.
Keeping cool is a challenge in the desert, where temperatures top 40 掳C in the shade. But Tricia Zubal at Arizona State University, Tempe, has found that the poisonous reptile can keep its body 3 掳C below the ambient temperature by allowing water to evaporate from its cloaca. This is the first time a reptile has been shown to cool itself this way. Her results were presented at the AAAS meeting in Denver, Colorado.
Why Gila monsters resort to this unusual measure rather than simply opening their mouths, as some other reptiles do, is not clear, but Zubal speculates that this might compromise the quality of their venom, which is released into the mouth like saliva.
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