冰冻星球（2011）

形成一层海冰
It forms a cover of sea ice
面♥积♥是欧洲的两倍，环绕整座大♥陆♥
that is twice the size of Europe and encircles the entire continent.
这处据点
This is a stronghold
栖息着南极洲最了不起的住民之一
for one of Antarctica's most remarkable inhabitants.
它用牙齿啃咬，防止换气孔冻结
It uses its teeth to prevent its breathing holes from freezing over.
威德尔海豹
The Weddell seal.
在地球最南端繁衍的哺乳动物
The most southerly breeding mammal on the planet.
这只十天大的幼海豹，仍完全依赖母亲
This ten-day-old pup is still entirely dependent on his mother. Out on the ice,
在冰层上或许能不受海洋掠食者的侵扰
这只十天大的幼海豹，仍完全依赖母亲
it may be safe from marine predators...
This ten-day-old pup is still entirely dependent on his mother. Out on the ice,
在冰层上或许能不受海洋掠食者的侵扰
it may be safe from marine predators...
可是在出生的两周内
...but within its first two weeks,
就必须冒险进入水下世界
it will have to venture into the underwater world
它的未来仰赖于此
upon which its future depends.
这是地球上最冰冷的水域
This is the coldest water on Earth.
因此不意外的是
So it's not surprising
小小的幼海豹需要一些鼓励
that a pup needs some encouragement.
现在该离开安全的换气孔了
It's time to leave the safety of the breathing hole.
为了能在捕到鱼后安全归来
To catch fish and then safely return,
这只幼海豹必须学会认路
为了能在捕到鱼后安全归来
this pup must learn how to find his way
To catch fish and then safely return,
这只幼海豹必须学会认路
this pup must learn how to find his way
在水下冰穴的迷宫中穿梭
through the maze of underwater ice caverns.
可是才刚过八分钟
But after just eight minutes...
母亲就示意应该返回
...his mother signals that it's time to head back.
它能够闭气一个半小时
She can hold her breath for an hour and a half.
可是幼海豹已经疲倦，而且就快没气了
But he is already starting to tire and is running out of air.
在返回换气孔途中
On their way back to their breathing hole,
它们听见如同战斗机一般的巨响
they hear a sound as loud as a fighter jet.
这是重达半吨♥的雄性威德尔海豹的呼唤
It is the call of a half-tonne male Weddell seal
宣告着它正在寻找交♥配♥对象
announcing that he's on the lookout for a mate.
然而这只雌海豹仍在为幼海豹泌乳
She, however, is still producing milk for her pup,
因此还不到受孕期
and so isn't sexually receptive.
但雄海豹并未停止尝试
But he doesn't stop trying.
为了吓阻它求爱
To repel his advances,
雌海豹会先离开幼海豹
she leaves her pup's side.
可是幼海豹还无力在缺少母亲的帮助下
But the pup isn't strong enough
自行上岸
to haul himself out without his mother's help.
它试图击退成年雄海豹
She tries to fight off the adult male.
它已给雄海豹重重一击
She's wounded him so seriously
短时间内不太可能再回来
that he is unlikely to be back any time soon.
母亲的轻轻一推
A gentle nudge from Mother
就是疲惫的幼海豹
is all an exhausted pup needs
回到安全的海冰上唯一所需
to make it to the safety of the sea ice.
母亲会陪伴幼海豹六个星期
Mothers stay with their pups for six weeks,
届时它们就够强壮，可以保护自己
by which time they're strong enough to fend for themselves.
春天降临，海冰就会退缩
As spring arrives, the sea ice retreats,
南极洲海岸有少数几个，能接触到无冰海面
and in a few places, Antarctica's coast is exposed to the open sea.
这能引来各式各样的动物
And that attracts all kinds of animals.
在海上过冬之后
Having spent the winter at sea,
颊带企鹅现在总算能上岸繁衍
chinstrap penguins can now come ashore to breed.
很快地，海岸就挤得水泄不通
Soon, the coast becomes extremely crowded.
但还是有办法能维持社交距离
But there are ways to maintain social distance.
天啊
Oh, dear.
幼鸟在长到八周大之前
The chicks, until they're eight weeks old,
都要仰赖父母提供食物和关乎生死的体温
depend on their parents for food and, critically, warmth.
融化的水是一大问题
Meltwater is a particular problem.
幼鸟的羽毛还无法防水
The chicks' feathers are not yet waterproof.
弄湿就可能致命
Getting wet could be fatal.
父亲的职责就是帮幼鸟保持干燥
A father's duty is to keep his chicks high and dry...
使用唯一能取得的建材
...using the only building material available.
石头
Stones.
而合适的石头更是珍贵难寻
And suitable ones are precious.
因此每一颗都务必要把握
So it's vital to hold on to every one.
就在转身背对时
But while backs are turned...
珍贵的藏品，遭到邻居迅速的掠夺
...collections are readily plundered by neighbours.
身边有这样的盗贼
With thieves like these around...
那颗石头变得更加珍贵
...that stone has just become even more valuable.
技能上的不足
What's lacking in skill...
就用坚持不懈来弥补
...is made up for with persistence.
可是父母的辛苦也可能徒劳无功
But a parent's labours could be in vain.
现今记录到的夏季气温，高达摄氏18度
Summer temperatures have now been recorded as high as 18 degrees Celsius.
结果就是企鹅悉心堆起的平台
As a result, the penguins' carefully constructed platforms
正遭到淹没
are now being flooded.
融水量是前所未有地多
There is more meltwater than ever before...
地面渐渐变成泥淖
...and the ground is becoming a quagmire.
在干燥时，隔绝寒冷能力优异的羽绒
Downy feathers, which are excellent insulation from the cold when dry,
潮湿时便毫无防御力
are no defence when wet.
失温悄悄来袭
Hypothermia sets in.
过去50年来
Over the last 50 years,
此地的颊带企鹅数量已经减少一半
the number of chinstraps here has dropped by half.
南极洲正在失去构筑其轮廓的重要元素
Antarctica is losing the very element that defines it.
冰
Ice.
如今消退的速度是原先的六倍
That is now diminishing six times faster than it once did.
南乔治亚岛上的纽梅耶冰河
Neumayer Glacier on South Georgia
短短20年间，就失去了近六英里长的冰
has lost nearly six miles of ice in just 20 years.
南极洲某些区域的暖化速度
Parts of Antarctica are warming faster than anywhere else
快过南半球任何一处
in the southern hemisphere.
对于生活在海岸上的动物
And that is having a serious effect
造成严重影响
on the animals that live on its coast,
像威德尔海豹
such as the Weddell seal.
由于海冰变少，有许多只能在陆上苦撑
With less sea ice available, many are now hauling out on land.
不只对它们造成问题
That's not just a problem for them...
同时还有专门猎捕它们的掠食者
...but also for the predators that specialise in hunting them...
南极虎鲸的其中一个族群
...one particular group of Antarctic killer whales,
数量多达一百头左右
100 or so animals strong.
虎鲸是人类以外，智慧最高的一种掠食者
Killer whales are among the most intelligent of all nonhuman predators.
它们正在研究要如何对付
And they're now working out how to tackle prey
不是威德尔海豹的猎物
that isn't a Weddell seal.
一只阿德利企鹅正在冰上休息
An Adelie penguin, resting on the ice.
对成年虎鲸来说只能算是点心
A mere snack for an adult killer whale...
却能让这群六岁的鲸鱼有机会
...but it gives this group of six-year-olds
练习它们其中一种格外高明的狩猎技巧
a chance to practise one of their particularly ingenious hunting techniques.
波浪冲击
Wave-washing.
这种技巧需要练习至少15年，才能娴熟
A skill that takes at least 15 years to perfect.
首先虎鲸要评估潜在对象的体型与位置
First, the killer whales assess the size and position of a possible victim.
接着必须计算进行攻击所需的速度
They must then calculate the speed needed for an attack.
可是它们晚了一步
But they're too late.
尽管透过协调良好的摆尾
Even though a co-ordinated flick of their tails
能产生够大的波浪
尽管透过协调良好的摆尾
creates a reasonable wave...
Even though a co-ordinated flick of their tails
能产生够大的波浪
creates a reasonable wave...
不能精准掌握时机也是惘然
...it's nothing without precision timing.
由于在浮冰上休息的偏爱猎物威德尔海豹变少
With fewer of their favourite prey of Weddell seals resting on ice floes,
虎鲸现在别无选择
killer whales now have no choice
只能锁定新猎物
but to target new prey.
食蟹海豹
Crabeater seals.
数量高达五千万头
Numbering 15 million,
它们是地球上最多的海洋哺乳动物
they're the most abundant marine mammal on Earth.
但它们这个目标却比威德尔海豹
But they are a far more dangerous target...
更加危险
...than a Weddell seal.
更强壮
Stronger...
也更勇于反击
...and more inclined to fight back.
可是这个鲸群的每个成员
But each member of this pod
每日需要吃一头海豹
needs to eat a seal a day.
因此觅食的压力不小
So the pressure is on to feed.
领导它们的雌性族长，深知该如何因应
They're led by a matriarch who knows exactly what to do.
活了至少一百岁的它
Living 100 years or more,
有丰富的狩猎经验可供汲取
活了至少一百岁的它
she has plenty of hunting experience to draw upon.
Living 100 years or more,