Mice Above 21,000 Feet: The Highest Mammals
Welcome back to Learn English with Podcasts! Sarah, what is the highest place you have ever stood?欢迎回到 Learn English with Podcasts！Sarah，你站过的最高地方是哪里？
Hmm, maybe the top of a tall building? Or a small mountain on a holiday. Nothing too serious.嗯，也许是一栋高楼的楼顶？或者假期里爬过的一座小山。没什么太厉害的。
Okay, now imagine standing almost 7,000 meters above the sea. The air is thin. It is below freezing. And a small mouse runs past your feet.好，现在想象你站在海拔近 7000 米的地方。空气稀薄，气温在冰点以下。然后一只小老鼠从你脚边跑过。
A mouse? Up there? No way. There is almost nothing to eat, and the air has very little oxygen.一只老鼠？在那上面？不可能。那里几乎没东西吃，空气里氧气也很少。
That is exactly what scientists thought. But it is true. The animal is called the Andean leaf-eared mouse, and it holds a Guinness World Record.科学家们原本也这么想。但这是真的。这种动物叫安第斯叶耳鼠，它还拥有一项吉尼斯世界纪录。
So how did anyone even find it? That mountain must be very hard to reach.那人们到底是怎么发现它的？那座山一定很难到达。
It started with a short video. Some local mountaineers filmed a mouse running across the snow at about 6,205 meters. They sent the video to a biologist named Jay Storz.一切都始于一段短视频。几位当地登山者拍到一只老鼠在约 6205 米的雪地上跑。他们把视频发给了一位叫杰伊·施托兹的生物学家。
And where was he when he got it?他收到视频的时候在哪里？
He was on sabbatical in Argentina. He is also a serious mountaineer, so he did not just watch the video. He decided to go and look for the mouse himself.他当时在阿根廷休假。他本人也是一名认真的登山者，所以他没有只看视频。他决定亲自去找这种老鼠。
Wait, a biologist who climbs mountains? That sounds like the perfect person for this.等等，一个会爬山的生物学家？听起来这活儿非他莫属。
Exactly. In 2020, his team went to a volcano called Llullaillaco. It is on the border between Chile and Argentina, and it is 6,739 meters high. That is about 22,110 feet.没错。2020 年，他的团队去了一座叫尤耶亚科山的火山。它位于智利和阿根廷交界处，高 6739 米，大约 22110 英尺。
22,110 feet. I cannot even imagine that. What is it like at the top?22110 英尺。我根本想象不出来。山顶上是什么样子？
It is a hard place for any animal. Temperatures rarely rise above freezing, and the air has less than half the oxygen you get at sea level.对任何动物来说那都是个艰难的地方。气温很少升到冰点以上，空气中的氧气还不到海平面的一半。
Right. Even very strong climbers can only stay there for a short time. So how did they catch a mouse?对。就连很强壮的登山者也只能在那里待一小会儿。那他们是怎么抓到老鼠的？
They set traps near the top and waited. And yes, they caught one on the summit. Later trips found more mice, and even active burrows.他们在山顶附近设了陷阱，然后等待。结果他们真的在山顶抓到了一只。后来的考察又发现了更多老鼠，甚至还有正在使用的洞穴。
So these mice are not just visiting. They actually live there.所以这些老鼠不是偶尔路过。它们是真的住在那里。
They live there. And the species has another surprising record. It lives from sea level all the way up to more than 6,700 meters. No other mammal has such a wide range.它们就住在那里。而且这个物种还有另一个惊人的纪录。它从海平面一直生活到 6700 多米高的地方。没有其他哺乳动物有这么大的分布范围。
Okay, that is the mystery. How does a tiny mouse survive cold and thin air that would make a human feel sick?好，谜题就在这里。一只小老鼠，怎么能在让人类难受的寒冷和稀薄空气里活下来？
The first part is heat. The highland mice can produce a lot of body heat by burning fat. Their muscles have more "power plants" that use oxygen.首先是热量。高地老鼠能通过燃烧脂肪产生大量体热。它们的肌肉里有更多利用氧气的"发电厂"。
Power plants in the muscle. You mean mitochondria?肌肉里的发电厂。你是说线粒体？
Yes. And in tests, the highland mice did better in cold, low-oxygen conditions than lowland mice of the same species. In simple words, their engines work better when the air is thin.对。在测试中，高地老鼠在寒冷、低氧的环境里，比同物种的低地老鼠表现更好。简单说，空气稀薄时，它们的"发动机"更给力。
So they are born with better engines. That makes sense.所以它们天生就有更好的发动机。这说得通。
But here is the part that surprised the scientists. The mice also have special genes for dealing with plant poisons.但接下来这部分让科学家们很意外。这些老鼠还有处理植物毒素的特殊基因。
Plant poisons? Why would a mountain mouse need those?植物毒素？一只山上的老鼠为什么需要这些？
Because life up there is not just snow and rock. The mice eat plants from the Andes, and many of those plants are full of chemicals that protect them from animals. The highland mice can break those chemicals down.因为那里的生活不只有雪和岩石。这些老鼠会吃安第斯山的植物，而其中很多植物充满用来防御动物的化学物质。高地老鼠能把这些化学物质分解掉。
So they are not only great climbers. They are also tough eaters.所以它们不仅擅长爬山，还特别能"吃"。
Right. And that changes the picture. The mountain is not just a cold, empty place. It is a whole world with food, poison, and competition.对。这改变了我们的理解。那座山不只是一个寒冷空旷的地方。它是一个有食物、有毒物、有竞争的世界。
Wait, I have another question. Why the Andes? Why not the Himalayas? They are even higher.等等，我还有一个问题。为什么是安第斯山？为什么不是喜马拉雅山？那边还更高。
Good question. The answer is the weather. The record was set in a very dry desert plateau called the Puna de Atacama. For much of the year, the peaks there have little ice and snow, so small animals can reach the top.好问题。答案是天气。这项纪录是在一个叫普纳-德阿塔卡马的极干燥高原上创造的。那里一年中大部分时间山峰上冰雪很少，所以小动物能到达山顶。
So on other mountains, the summit is locked under ice. Here, the door is open.所以在其他山上，山顶被冰雪封住了。而在这里，门是开着的。
Exactly. And here is a fun detail. The Inca people also built shrines on the tops of these same peaks. No snow, so they could climb.没错。还有一个有趣的细节。印加人也曾在这些同样的山峰顶上建神龛。因为没有雪，所以他们能爬上去。
So humans and mice used the same mountain roads. Just at very different times.所以人类和老鼠用的是同一条山路，只是时代差得很远。
Yes. The Inca built temples, and the mice built burrows. Both found a way to live above the clouds.对。印加人建神庙，老鼠挖洞穴。它们都找到了在云层之上生活的方法。
I love that. So what does this study teach us, beyond one cool record?我很喜欢这个说法。那么除了一个很酷的纪录，这项研究还告诉我们什么？
It shows that the limits of life are not fixed. When scientists look closely, they often find life in places they thought were empty.它说明生命的边界不是固定的。当科学家仔细去看，常常会在以为空无一物的地方发现生命。
And the video? The one that started everything?那那段视频呢？就是开启这一切的那段。
Storz joked that a mouse running in the snow would never go viral on TikTok. But that little video led to years of expeditions, a Science paper, and a place in the Guinness Book of World Records.施托兹开玩笑说，一只老鼠在雪地里跑，永远不会在 TikTok 上火。但那段小小的视频带来了多年的考察、一篇《科学》论文，还有吉尼斯世界纪录里的一席之地。
So much for TikTok. Sometimes the quietest video has the loudest ending.TikTok 可看不出来。有时候最安静的视频，结尾最响亮。
And the mouse? It is still up there, small, fast, and completely at home. Thanks for listening, everyone. See you in the next episode!那老鼠呢？它还在上面，小小的、飞快的，完全把那里当成了家。谢谢大家收听，我们下期见！