雷鸟: 身壮如牛、追着雷跑的大鸟

如果无法播放，请点击此处在新窗口打开

雷鸟: 身壮如牛、追着雷跑的大鸟(上)
So, yeah, so very unlike a bird that you typically think of sitting at a bird feeder-you know, definitely not that kind of bird.
是的，一点也不像你通常看到的停在喂食器旁边的鸟，绝对不是那种鸟。
I'm Flora Lichtman, with Scientific American's Science, Quickly.
我是《科学美国人》科学快播栏目的弗洛拉·里奇曼。
Today: episode three of our four-part fascination on really big birds. We're going on a gargantuan goose chase.
今天是“魅力大型鸟类”四集系列节目的第三集。我们将继续聊巨型大鹅。
I love talking about these big birds because, as you see, most people, you know, think ostrich, and they think that's big. But actually they were real giants around at one time.
我喜欢谈论这些大鸟。因为，如你所见，大多数人都认为鸵鸟体型很大。但实际上这些鸟类在过去才是真正的庞然大物。
This is paleontologist Anusuya Chinsamy-Turan of the University of Cape Town in South Africa.
这是南非开普敦大学的古生物学家金萨米·杜蓝(Anusuya Chinsamy-Turan)。
She's talking about the dromornithids. That's their scientific name. But in big bird circles, you'll hear them called thunderbirds.
她说的是雷啸鸟。这是它们的学名。但在大鸟圈，你会听到它们被称为雷鸟。
And I think the name the thunderbirds is really quite wonderful because it kind of immediately-you know, you can understand these really large animals are coming.
我认为雷鸟这个名字非常贴切，因为马上你就知道这些巨兽要来了。
Thunderbirds lived in Australia, and they had a long run.
雷鸟栖息在澳大利亚，可以长距离奔跑。
The earliest members of the group date back 50 million years or so, and one species persisted to about 40,000 years ago.
这个鸟群的初期成员可以追溯到大约5000万年前，而且其中一种鸟坚持到了大约4万年前才消失。
And there was one thunderbird that was more thunderous than the rest.
有一只雷鸟的声音比其他的鸟都要响亮。
The largest are the thunderbirds called Dromornis stirtoni. And they are known from the late Miocene, about eight million years ago.
体型最大的雷鸟是史氏雷啸鸟(Dromornis stirtoni)。生活年代为中新世晚期，约为800万年前。
Here's what to picture.
以下是对其形象的描述。
It's like an overgrown ostrich, you know. Think about an ostrich, just kind of bigger-big beaks; the bones would have been heavier, more bulkier, more robust ...
它就像一只发育过度的鸵鸟。想想鸵鸟的样子，只是它的体型更大，鸟喙也更大; 骨头更重、更庞大、更结实……
But, like, a lot bulkier and more robust.
不过，雷鸟更庞大，更结实。
Absolutely. They are some of the hugest birds on the planet-were on the planet.
绝对如此。它们是地球上最大的鸟类之一。
This is paleontologist and thunderbird expert Trevor Worthy.
这是古生物学家和雷鸟专家特雷弗·沃西。
They got up to a whopping great 1,300 pounds, which is quite a lot, ten times a human.
它们的体重惊人，重达1300磅，相当重，是人类的十倍。
A bird the size of a cow.
个大如牛的鸟。
Yeah.
是的。
They were huge in … almost every way.
无论从哪里看，它们都是庞然大物。
They've got no discernible wings. The bit that pokes out of the side of the body is four inches. It isn't going to make a dent in the feathers.
雷鸟翅膀的轮廓无法辨认。从鸟身侧面伸出来的部分有4英寸(约10厘米)长。羽毛上无法凹出翅膀的痕迹。
They're not flying. Their closest living relatives are ducks and geese.
雷鸟不会飞。它们现存的近亲是鸭和鹅。
And that's another thing you could picture: just a gigantic goose trundling across a lush landscape-Australia was greener eight million years ago-grazing on plants and fruits.
你可以想象这样一个画面: 一只巨大的鹅在郁郁葱葱的地面上缓慢移动——澳大利亚800万年前的草地更绿——吃植物、吃水果。

轻音乐播放地址

如果无法播放，请点击此处在新窗口打开

雷鸟: 身壮如牛、追着雷跑的大鸟(中)
Trevor says the thunderbirds' vegetarian diet might partly explain their size.
特雷弗认为，雷鸟食素的饮食习惯可能是它们体型庞大的部分原因。
You can get big; you can have a big gut. And then you can eat a lot of rubbish.
你的体型会变大; 你的胃会变得很大。你可以吃进很多劣质食物。
So if you can ingest a lot of low-quality food, then that is one way of living in an environment.
如果你可以摄入大量品质低劣的食物，那也是在环境中生存的一种方式。
Their big body probably helped them in other ways, too.
雷鸟庞大的身体可能也在其他方面帮助了它们。
Here's Anusuya again.
以下是金萨米的观点。
Their body size probably evolves in the context of what else is around at the time.
它们的体型可能是根据当时周围的环境而进化的。
In Australia, there were these thylacines. There are these marsupial lions, and I think a big body size would have enabled them to escape predation.
澳大利亚有袋狼，也有袋狮，我认为雷鸟巨大的体型可以让它们逃脱被捕食的命运。
They're just too big to eat.
雷鸟体型太大了，没法吃。
Yeah. Or otherwise it's too much of trouble to deal with them. You know, you rather go after something that's smaller, that's not going to harm you.
是的。处理雷鸟实在太麻烦了。它们宁愿去找一些体型更小的动物，也不愿伤害雷鸟。
Because, I think, you know, we know ostriches certainly are not predators, but an ostrich can do pretty serious damage to, to any animal that attacks it just by kicking.
因为，我们当然知道鸵鸟不是捕食者，但鸵鸟可以对任何攻击它的动物造成严重伤害。
And if they're related to geese, I mean, we all know how terrifying geese can be.
如果雷鸟是鹅的近亲，我们都知道鹅有多可怕。
Yes. You know, I had a friend earlier this year that was attacked by a goose, and you're not going to believe this, but literally, she had to be hospitalized because this goose attacked out of nowhere.
是的。年初，我有个朋友被一只鹅袭击了，你不会相信，实际上，因为这个不知道从哪里冒出来的鹅袭击了我朋友，她不得不住院。
Just imagine if that goose was, you know, 1,300 pounds.
想象一下，如果那只鹅有1300磅重。
Exactly. Exactly.
是的，正是如此。
But how did they grow so big? That's something Anusuya wanted to understand.
但它们是怎么长这么大的呢? 这正是金萨米想要了解的。
To drill down on that question, she took a very thin section of a thunderbird bone and looked at it under the microscope.
为了深入研究这个问题，她从雷鸟的骨头上取了一小部分，放在显微镜下观察。
And this is fascinating because it tells us about the way in which the bone was deposited. So it tells us about the rates of growth.
这很有趣，因为这展示了雷鸟骨头沉积的方式以及骨头生长的速度。
Bones have rings that correspond to growth. Like tree rings…
骨头上有与生长相对应的骨轮。与树的年轮一样……
Where you have a white band that is growth during the favorable season, and then you have a growth line that indicates growth stopped for a period of time, and then afterward, it resumes.
这里有一个白色条纹，表示生长在适宜的季节里，之后出现了一条生长线，表示生长停止了一段时间，之后又恢复了生长。
So just like tree rings, you can count the number of rings, and you can work out the age of the animal, and you can work out how long it took for an animal to grow to an adult body size.
就像树木的年轮一样，你可以数年轮的圈数计算树龄，同样，你也可以计算出雷鸟的年龄，你可以计算出雷鸟长到成年体型需要多长时间。
This bone ring method is a feather in Anusuya's cap-she developed it when she was just a fledgling Ph.D. student working on dinosaurs.
这种骨轮法是金萨米的得意成就——当她还是一名研究恐龙的初出茅庐的博士生时，她就发明了这种方法。
And when she applied the method to this giant thunderbird, she found ...
当她把这种方法应用到这只巨大的雷鸟身上时，她发现…...
These birds lived life in the slow lane.
这些鸟生活节奏很慢。
We can find growth cycles in the bones that suggest that they took about 15 years to reach an adult body size.
我们可以发现生长骨环，这表明雷鸟花了大约15年的时间才达到成年体型。
And this is really a long time, compared to modern birds that grow up very quickly.
与现代生长得很快的鸟类相比，这真的是很长的一段时间。
And it took them years to have babies, too, the data suggest.
数据显示，雷鸟要花很多年才能产下幼崽。
Anusuya and Trevor say that gives us some insight, into why these birds don't exist today.
金萨米和特雷弗表示，关于为什么这些鸟今天不存在了，这给了我们一些启发。
轻音乐播放地址

如果无法播放，请点击此处在新窗口打开

雷鸟: 身壮如牛、追着雷跑的大鸟(下)
If life is easy-if there is enough food and not a lot of pressure from predators-you can take your time to grow up and have babies.
如果生活很轻松——如果有足够的食物，没有来自捕食者的太多压力——你就可以慢慢生长，产下幼崽。
But this can be a riskier strategy when life is tough. And life did get tough for thunderbirds.
但当生活艰难时，这可能是一个风险更大的策略。雷鸟的生活确实很艰难。
After eight million years ago, Australia became more arid. And that's when the giant D. stirtoni disappears. Humans arrived in Australia around 50,000 years ago, and soon after, you don't find any species of thunderbirds at all.
800万年前，澳大利亚变得越来越干旱。这时巨大的史氏雷啸鸟消失了。人类大约在5万年前到达澳大利亚，不久之后，你就找不到任何雷鸟了。
Having the strategy of life in the slow lane didn't facilitate being able to deal with something new in the environment, which is taking out numbers of their young.
缓慢生长的生活策略并不会有助于它们处理环境中的新情况，而这正在夺走许多年轻雷鸟的生命。
This theory is backed up by another bird tale. Consider the emu, a different big bird that lived alongside the thunderbirds.
这一理论得到了另一种鸟类传言的支持。想想鸸鹋，另一种与雷鸟生活在一起的大鸟。
An emu, in contrast, it will grow to full body size in 14 months and is breeding shortly after that.
相比之下，鸸鹋在14个月内就会长到成年体型，此后不久就开始繁殖生育。
And while the thunderbirds went extinct, the emu survived.
虽然雷鸟灭绝了，但鸸鹋却活了下来。
It survives because its growth rate is so much faster, so it is able to reach an adult size very quickly, it reproduce very quickly, and it's able to recoup its numbers very quickly.
鸸鹋幸存下来是因为它的生长速度快得多，能很快达到成年体型，繁殖得也很快，能很快恢复到原来数量。
And that's something to think about.
这是值得思考的问题。
Because many of the birds at our feeders, flapping around our cities, pooping on our cars-they live life in the fast lane. They grow up quickly and have babies early.
因为我们喂食器旁的许多鸟儿，在城市里飞来飞去，在汽车上拉屎——它们的生活节奏很快。它们长得快，生得早。
And in an uncertain world, filled with two-legged jerks who make life hard for other animals, this strategy has advantages.
在一个不确定世界里，那里满是让其他动物生活艰难的两条腿傻瓜，这种策略有其优势。
So I think that when you see a pigeon or a robin, one should appreciate that they are the end products of a long evolutionary history, that there were many other forms that came before them.
我想，当你看到一只鸽子或一只知更鸟时，你应该意识到它们是漫长进化历史的最终产物，在此之前还有许多其他形式的物种。
And I think the giant birds, they also are part of this evolutionary history of all modern birds that we see today.
我认为这些大型鸟类，它们也是我们今天看到的所有现代鸟类进化史的一部分。
On the next Science, Quickly: when a big bird becomes an axe murderer.
下一期科学快播: 当一只大鸟变成斧头杀手时。
Terror birds do not follow the general rules of, of birds. They use the beak as an axe to kill prey.
恐鸟不遵循鸟类的一般规律。它们把喙当作斧头来捕猎。
That's terrifying.
太可怕了。
Well, that's why they are terror birds.
这就是它们名字的由来。
You've just listened to Part Three in a four-part Science, Quickly, fascination on really big birds.
你刚刚收听的是“魅力大型鸟类”四集系列节目的第三集。
Science, Quickly is produced by Jeff DelViscio, Tulika Bose and Kelso Harper. Our theme music was composed by Dominic Smith.
“科学快播”栏目由杰夫·德尔维西奥、图利卡·博斯与凯尔索·哈珀制作。本栏目主题音乐由多米尼克·史密斯制作。
Don't forget to subscribe to Science, Quickly wherever you get your podcasts. Head over to ScientificAmerican.com for in-depth science news.
无论你从哪里打开播客，不要忘记订阅“科学快播”。前往ScientificAmerican.com获取深度科学新闻。
For Science, Quickly-I'm Flora Lichtman.
感谢收听“科学快播”--我是弗洛拉·里奇曼。
轻音乐播放地址