自然界大事件（2009）

太阳的能量
The power of the sun
推动着四季的变化 影响着地球的变迁
drives the seasons, transforming our planet.
浩瀚洋流和气流的运动
Vast movements of ocean and air currents
带来令人叹止的巨变 终年不息
bring dramatic change throughout the year.
在地球上某些特殊的地区
And in a few special places, these seasonal changes
季节变化造就了壮丽无比的自然奇景
create some of the greatest wildlife spectacles on Earth.
北极的夏天 阳光开始融化冬季的冰雪
Here in the Arctic each summer, the sun begins to melt the winter ice.
近三百万平方英里的冰层随之消融
Nearly three million square miles of ice will disappear,
数百万的动物迎来了一线生存良机
opening up a narrow window of opportunity for millions of animals.
对大多数动物来说 这是生息和繁衍的最佳时期
For many, it's their best chance to feed and breed.
但对北极熊来说 却是一年中最难熬的日子
But for polar bears, it's the hardest time of the year.
它们不得不在季节变换中艰难求生
They have to survive the greatest seasonal change on the planet.
自 然 界 大 事 件
世纪大消融
画外音
大卫 · 爱登堡 爵士
北极的冬天
Winter in the Arctic.
摇曳的北极光横跨在天际
The northern lights flicker across the sky.
这里成了极夜的世界
It's a land of continuous night
气温骤降到零下40度
where temperatures plummet to minus 40.
北极熊处在最佳生存环境中
Polar bears are in their element,
它在结冰的海面上捕食海豹
hunting for seals on the frozen sea.
但长夜终将过去
But the long night is coming to an end.
二月露出的第一缕曙光
In February the sun rises
结束了长达四个月的黑暗
for the first time in four months.
在未来几周内 太阳的力量
In the coming weeks the strength of the sun
将使一切变得面目全非
will power an enormous change.
可现在这一刻的阳光却是温暖的
But for now its rays offer only a little warmth.
尽管阳光重现 地球最北端六百万平方英里的面♥积♥
Despite the sun's return, six million square miles of the planet's far north
仍是一片冰天雪地
is still cloaked in ice.
厚厚的积雪覆盖着山川
Deep snow covers the mountains.
海面上也结着几米厚的坚冰
Even the sea is frozen solid, many metres deep.
成群的环斑海豹从冰洞中爬出来
Groups of ringed seals haul out through holes in the ice
享受着淡淡的阳光
to bask in the weak sunlight.
但它们很脆弱 随时保持着警惕
But they are vulnerable and have to keep a lookout.
冰层还很结实 肉食动物很容易靠近
With the sea still frozen, it's easier for predators to get close,
海豹最大的天敌就是北极熊
and the seal's greatest enemy is the polar bear.
一只母熊和它四个月大的小熊正在觅食
A mother bear and her four-month-old cub are hunting.
海豹是它们主要的食物
Seals make up most of the bear's diet,
母熊必须带着孩子到冰上寻找食物
and to find them she must lead her youngster out onto the ice
这是小熊初次外出
for the first time.
为了观察气候变化对北极熊的影响
Scientists, looking at how a changing climate is affecting bears,
科学家给母熊装上了无线电项圈
have fitted the female with a radio collar.
这块冰层有些薄
The ice here is thinner,
母熊必须伸展身体 分散体重压力 避免冰层破裂
and she must spread her weight to avoid breaking through.
而小熊却乐在其中
For her cub, it's all just a game.
紧跟着妈妈 它将学习生存最重要的一课
By sticking close to Mum, he'll learn how she hunts for seals,
如何捕捉海豹
a critical lesson for his future survival.
此时严寒的北极 鲜有生命存在
At this time of year the frozen Arctic is empty of life
仅有少数耐寒的居住者能够生存
and only a few hardy residents can survive.
对这只雌性北极狐来说 冬天是饥饿的时节
For a female arctic fox, the winter has been a time of hunger.
食物太少了 她只得到更远的地方去寻找
Food is scarce and she's had to wander far and wide,
北极熊吃剩下的残骸
scavenging from the remains of bear kills.
它终于时来运转
But her fortunes are changing.
找到一只驯鹿的残骸
A dead reindeer is a lucky find.
如果没有别的食腐动物出现
If no other scavengers come along,
这顿饭会支撑着它过完这个冬天
this could sustain her for the rest of the winter.
趁海面还结着冰 北极熊忙于捕食
With the sea frozen, polar bears are busy hunting.
这只北极熊抓住了一只海豹
This bear has caught a seal.
它等着海豹从冰洞中钻出来
He waited for it to surface through a hole in the ice
它的耐心有了回报
and his patience has been rewarded.
它必须每周捕捉一只海豹 现在是捕猎的大好时机
He must catch a seal about once a week, and this is the best hunting season.
只要海面还有冰 北极熊就不会挨饿
As long as there is sea ice the bears won't go hungry,
因为在冰面上行走是接近海豹最简单的方法
as walking on the ice is the easiest way for a bear to get close to a seal.
但冰层很快便会破裂 捕食将变得困难
But the ice will soon start to break up and hunting will get harder.
现在吃下去的食物的热量
The calories the bear takes in now
必须支撑它渡过即将到来的艰难日子
will have to see him through hard times ahead.
对北极熊而言是最肥者生存
For polar bears it's the survival of the fattest.
这段时间每天仅有五小时日照
At this time of year there are still only five hours of daylight.
但随着太阳高度角的增大 每天日照时间会增加40分钟
But as the sun rises higher, each day lasts 40 minutes longer.
三月 阳光逐渐增多
It's March, and with increasing sunlight
首先是一大批候鸟回归了
the first in a huge wave of migrants are arriving.
数百万只海鸟飞向北方冰冻的海岸
Millions of seabirds are travelling north to reach the frozen coast.
成群结队的海雀和海鸠
Huge flocks of little auks and guillemots
飞过数百里漂着浮冰的海域
fly across many miles of ice from the nearest open water.
它们的目的地 是仍被冰雪覆盖的海崖
Their destination is the still-frozen sea cliffs.
现在这里并不适宜居住
It's an inhospitable place,
但几周后这一切都会改变
but in a few weeks everything here will change.
早起的鸟儿有虫吃 尽管积雪尚未融化
It pays to be early, even though the snow has yet to melt.
但先到的鸟儿能优先占领好的窝点 率先动工
The first arrivals get the best nesting ledges and a head start.
它们只有50天的时间来产卵并孵养小鸟
They have just 50 days from laying their eggs to raise their chicks.
寂静的北极旷野又恢复了生机
The Arctic's silent wilderness is coming to life.
太阳重现已有三个月 它的能量与日俱增
It's three months since the sun's return and its power is growing daily.
气温慢慢升高
The air temperature rises slowly
终于达到零度以上 大融化开始了
and once above zero, at long last, the melt begins.
融化的积雪汇成溪水 奔流着离开陆地
Melting snow feeds freshwater streams which pour off the land.
几天后会呈现出一派崭新的风景
In just a few short days, the melt unveils a whole new landscape.
现在的海崖上挤满了筑巢的海鸟
The coastal cliffs now teem with nesting seabirds,
随即也招来了一些不速之客
and it's not long before they attract unwelcome attention.
狐狸的白色冬衣和积雪一起褪去
The fox's white winter coat has disappeared with the snow.
新皮毛的掩盖使它从食腐者变成了狩猎者
Her new camouflage will allow her to change from scavenger to hunter.
短暂的夏天是它养家糊口的好时机
The short summer will be her best chance to raise a family.
陆地上的冰雪是消失了
The snow may be disappearing from the land,
但海冰还未融化
but the sea ice has yet to melt.
海岸线仍被冰雪覆盖
The coastline is still locked in ice.
北极的岛屿
The islands of the Arctic
被数千英里冰封的白色海洋所包围
are surrounded by thousands of miles of white frozen ocean.
因为冰层很厚
Because the sea ice is so thick, it won't begin to break up
气温要数日持续零度以上 才能使之融化
until the temperature stays above zero for a number of days.
在这之前 没有多少生物能穿破冰层的阻碍
Until then, few creatures can penetrate this icy barrier.
白色冰面反射阳光
The sun reflects from the white frozen sea,
形成冰上海市蜃楼
creating a desert of icy mirage.
北极熊还能在冰面行走捕捉海豹
The bear can still walk on the ice to hunt for seals,
但好景不长
but not for much longer.
天气一天比一天热
It's getting warmer by the day.
北极熊的天地即将消融
The bear's world is about to melt away.
六月 太阳一天24小时炙烤大地
It's now June and the sun beats down 24 hours a day.
气温一直维持在零度以上
The temperature remains constant above zero degrees.
冰封的海面开始融化
The frozen sea begins to melt.
布满冰面的小水洼 吸收了更多太阳能量
Pools form across the surface, absorbing more of the sun's heat,
加快了消融速度
speeding the thaw.
阳光穿透冰层
Sunlight penetrates the frozen surface,
照亮了奇异的冰下世界
illuminating a strange world beneath the ice.
冰层开始破裂
The frozen barrier has split.
各种神秘的声音此起彼伏 回响在冰层之下
Mysterious voices echo against the icy ceiling.
巨大的裂缝或者通道 从冰层较薄处断开
Giant cracks, or leads, form at weak points,
为新的访客敞开道路
creating a pathway for new arrivals.
角鲸
Narwhal.
由于它那奇特的螺旋型长牙 它被誉为北极的独角兽
Known as the arctic unicorn because of their strange spiral tusks,
角鲸是海洋中最为神秘莫测
narwhal are some of the most secretive and elusive animals
的动物之一
in the world's oceans.
成千上万神秘的角鲸经由这些通道前往北极
The leads provide passage for thousands of these mysterious whales.
每个夏季 它们向北穿越600英里
Each summer they travel 600 miles north,
越过冰雪抵达这富饶的渔场
navigating through the ice to reach rich fishing grounds.
更多的鲸顺着沿海的冰块边缘长途跋涉
More whales travel along the edge of the ice where it meets the open sea,
来寻找新道路的开口
to search for the openings of leads.
这是个冒险的旅程 它们是哺乳动物 需要呼吸空气
It's a hazardous journey. As mammals, they need air to breath
它们头顶的冰块闭合 它们就有可能窒息而死
and if the ice closes above them they could suffocate.
它们在寻找能让它们浮出水面的冰窟
They're looking for holes in the ice where they can surface.
一次呼吸能让它们坚持15分钟
A single breath will last them for 1 5 minutes.
游的越远 就越难找到冰窟
The further they travel, the harder it becomes to find holes in the ice.
它们抓紧深吸几口气 然后继续前行
They snatch a breath and then travel on.