时差N小时 为什么会有那么多死蛇在路上?（在线收听）

It's a familiar sight: you're driving along one of those long, dry stretches of highway in any of the southwestern states, and you keep coming across snakes that have been run over by cars. Why should snakes have worse luck with cars than any other desert animal does?

很熟悉的一幕：当你驾车在西南各州沿着其中一条又长又干燥的高速公路行驶时，你会不断遇到被汽车碾压过的蛇。为什么蛇比其它野生动物更加不幸得成为了车轮的牺牲品呢？

One reason is that snakes are cold-blooded—that is, their body temperature isn't maintained internally the way ours is, but fluctuates with the temperature of their environment.

原因之一是蛇是冷血动物，这就意味着它的体温不会像人类一样保持恒温，而是随着环境的温度变化而变化。

If you are cold-blooded and you live in the desert, you will find yourself getting very chilly at night, because sandy terrain does not hold heat very long after sunset. To get around this, snakes will often "bask" on warm rocks; and they also seek hot places to help aid in their digestion. This, in fact, is true of any snake, no matter what part of the country you find them in.

如果你是冷血动物，并且也住在荒漠，你会发现夜晚你的身体变得异常冰冷。因为日落后沙地不会长时间保持热度。为了解决这个问题，蛇类经常在温暖的岩石上“晒太阳”；它们也会寻找炎热的地方帮助消化。实际上任何蛇都是这样，不论是在国内哪个地方，都能找见它们。

The deserts just make a particularly clear case exactly because they do get cold so fast at night, and snakes can't hide out in wooded or grassy areas. Now you can probably see the problem that comes when human beings enter into the picture. When we move into deserts, we build those long roads out of asphalt and other materials that retain heat long after the sun has gone down. Desert snakes come out to bask away the cold hours on these convenient stretches of warmth. And, well...that turns out to be a mistake.

沙漠让情形变得更加特殊，因为在夜里蛇的体温降低过快，而且不能藏在树林或者草地里。现在你能想象到当人类进入荒漠会引起什么麻烦。人类进入荒漠，用沥青和其它可以在日落后长久保温的材料铺路。荒漠里的蛇跑出来在这块温暖的乐土上消磨寒冷的时光。然而，事实证明这是错误的选择。