(完整版)BBC生命第三集

第三集：哺乳动物

南极Antarctica.

地球上最寒冷地方The earth's coldest continent

极度不适合生物生存the one that is most hostile to life.

这里，距离南极点800英里Here

零下40摄氏度it's 40 degrees below zero.

地球上数百万种动物中Of all the millions of species of animals on Earth

只有一种能一直在此生存only one can live here permanently.

威德尔海豹A Weddell seal.

它能生存是因为可以潜到冰层下面She can survive because she can dive below the ice.

使自己不受上面的暴风雪袭击Here she is protected from the storms above

这里也能找到食物and here too

但它是哺乳动物，必须呼吸空气But she is a mammal

所以它必须守住一条通到冰层上面的生命线so she has to keep a lifeline open to the world above the ice.

不只是为自己Not only for her

也为刚出生的幼仔but now for her newborn pup.

SEAL GRUNTS

PUP CRIES

它还没一周大，仍旧很脆弱He's less than a week old

暴风雪来袭，力量强劲A blizzard blows in

可以持续一周It could last for a week.

作为哺乳类，海豹可以体内产热Being mammals

皮毛下面是一层厚厚的脂肪And their fur

能防止绝大多数的热量散失prevents most of that heat from escaping

即便是在这么冷的情况下even in cold conditions like this.

更重要的是，它能用哺乳动物所特有的What is more

乳汁，来哺育后代with that mammalian speciality

哺乳时，它还为幼仔遮挡住暴风雪And while she does so

整个冬天，它都孜孜不倦地工作She has worked hard throughout the winter to prevent her breathing hole

防止通气孔被冰冻封住in the ice from freezing over.

这需要持久的专注That requires constant attention -

用牙齿清除洞周围的冰filing back the edges of the hole with her teeth.

一旦幼仔长到适合游泳，就得跟它一起下水Her pup needs to join her under the ice as soon as he can swim properly.

它鼓励它第一次下水She encourages him to take his first plunge

奇怪的是，它一点也不紧张hardly surprisingly

现在，在妈妈的指导下，它要学习如何在水下捕食Now

同时能够在水下迷宫里找到返回通气孔的路and to find his way back through the maze to his hole in the ice.

体温、皮毛、乳汁以及母亲的呵护A warm body

是海豹在这严寒里生存必不可少的for the Weddell seal's survival in this freezing environment. 这些特点有助哺乳动物And those qualities have helped the mammals

统治整个地球to colonise the entire globe.

东非赤道地带Equatorial East Africa.

是一个与南极洲完全不同的世界It's hard to image a place more different from Antarctica.

要在这里生存，哺乳类需要额外的智慧To survive here

这三个窝点是一种小动物的领地This tree shelters the territory of a tiny mammal

花费了它毕生的精力辛勤打理that spends its whole life in frenzied activity.

以前被称作长鼻鼩It used to be called an elephant shrew

现在有个非洲化的名字：森吉（扎伊尔硬币）but now it's called by its African name of sengi. 这是一只红褐色的雌性sengi This is a female rufous sengi.

就像所有的sengi一样，它太活跃，总是吃不饱And

为了得到足够的食物To get all the food she needs

它必须勤劳而又灵巧she has to be both industrious and ingenious.

它为设计了错综复杂的路线She has made an intricate network of trails

帮助自己有效地猎食昆虫that enable her to hunt her insect prey very efficiently.

但这些通道在遭遇天敌时But these pathways have another important function

有重要的作用when she meets her enemies.

能否在头脑中牢记这张路线图关系着Having a map of these trails in her head can mean the difference

生存between life...

或死亡..and death.

跟爬行类不同，像大多数哺乳类Like most mammals

它的腿长在身体正下方（爬行类在身体两侧）her legs are directly beneath her body.

这使它不太稳定，但是更加迅速灵巧That makes her less stable

它不但比这只蜥蜴跑得快，更比它聪明Not only has she outrun this reptile

还有And just as well

它是一位需要照顾幼仔的母亲for she is a mother and has a youngster to care for.

sengi依靠速度和智谋取得成功The sengi relies on speed and cunning for its success.

其它的哺乳类有不同的技能Other mammals have very different techniques.

ANIMALS CALL OUT

马达加斯加Here in Madagascar

一种最为怪异的哺乳动物正在游荡one of the most bizarre of all mammals is on the prowl.

长指狐猴，跟sengi一样，吃昆虫The aye-aye

但它看不见所找的食物But the ones that she seeks

因为它们躲在树干深处for they're buried deep inside branches.

它们是挖虫高手They're beetle grubs.

为找到食物，它有特殊天分To find them

它用手指以每秒8次的速度敲击树干She taps her fingers on the wood up to eight times a second

通过分辨回声中的细微差别and listens for the tiny change in resonance

侦测出里面是否有洞that indicates a hollow spot within.

它的听力及其灵敏，能准确定位Her hearing is so acute

然后咬开树皮，找到虫子in which to gnaw a hole in order to reach the grub.

用它变态的超长中指And she has a grotesquely long middle finger

刺入洞中抓虫with which to skewer it.