自然界大事件（2009）

太阳的能量 推动着四季的变化
The power of the sun drives the seasons,
影响着地球的变迁
transforming our planet.
浩瀚洋流和气流的运动
Vast movements of ocean and air currents
带来令人叹为观止的巨变 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.
其中最显著的巨变之一
One of the most remarkable transformations
就发生在此处 南美的卡拉哈里沙漠里
occurs here in Southern Africa, in the desert lands of the Kalahari.
大群的动物历经数月跋涉 寻找食物和水源
Large herds of animals trek for months in search of food and water,
并等待着一件将完全改变他们生活状况的大事发生
waiting for an event that will dramatically change their lives.
一年一度 生命之泉奥卡万戈河（位于非洲西南中部）
For once a year, life-giving water turns an area of unforgiving desert
都会将荒芜贫瘠的沙漠 变成广阔潮湿的天堂
into a vast, watery paradise known as the Okavango.
奥卡万戈河的洪水 将于何时何地发生
Where and when the Okavango will flood
决定着数百万动物的命运
determines the fate of millions of animals,
因此也成为了 自然界举足轻重的大事件之一
making this one of nature's truly great events.
自 然 界 大 事 件
奥卡万戈大洪水
画外音
大卫 · 爱登堡 爵士
在南非的心脏地带 卡拉哈里沙漠
In the heart of Southern Africa, the desert lands of the Kalahari
覆盖近40万平方英里的土地
cover an area of almost 400,000 square miles.
这是世界上最干旱的地区之一
It's one of driest places on Earth,
然而大量的草食动物 却能奇迹般的生存下来
yet miraculously, great herds of grazing animals survive here.
他们四处漂泊
They lead a nomadic existence,
为了寻找食物和水源而颠沛流离
trekking huge distances in search of food and water.
旱季才刚刚开始 八个月之内都不会下雨
It's the start of the dry season. It won't rain for eight months,
早已艰辛的生活 将变得更加艰难
and so life, already hard, is about to get even harder.
在所有的动物中
Of all the animals here,
也许大象是最为足智多谋的
perhaps the most resourceful are the elephants.
每个家族都由一位年长的女族长带领
Each family is led by an older female, the matriarch,
并凭着她的经验率领大家穿过沙漠
and they all rely on her experience to guide them through the desert.
多年的生活经验告诉她 有一天
Her years here have taught this matriarch that, one day,
在西边几百英里的地方 她终将找到一片苍茫葱郁的草原
hundreds of miles to the west, she will find a lush grassland.
但在找到之前
But before she will find it,
她的家族得在沙漠中艰苦的生存数月之久
her family will have to survive many months in the desert.
那能改变他们生活的甘泉
The water that could transform their lives
其源头却远在千里之外
has its origins a thousand miles away,
是那安哥拉高原上的乌云
in the rain clouds over the highlands of Angola.
这丰沛的雨水有滋润沙漠的能力
The rain is so plentiful it has the power to transform a desert.
它奔流向南 不入海洋 却向着卡拉哈里沙漠的中心
It cascades southwards, not to the sea, but into the heart of the Kalahari,
一块手掌形状的盆地涌去
towards a basin shaped like a hand
这里就是奥卡万戈河
known as the Okavango.
在这里 入口处的湿地将被水流注满
Here it will fill the swamp that lies at its entrance.
只有当雨量特别丰富时
And only if the rains have been plentiful
水才会满溢 流向外部干旱的平原
will water flood out onto the arid plains beyond,
将它们滋养成绿草如茵
transforming them into the grassland paradise
动物们无比向往的乐土
that the herds so badly need.
在沙漠 大象每三天都需要补充水分
Out in the desert, the elephants need to find water every three days.
口渴的大象争先奔向水塘
Thirsty elephants often race into pools,
但女族长知道 争抢毫无意义
but the matriarch knows that her family must not rush in.
这是一潭死水
This pool is stagnant,
但大象找到了喝清水的窍门
and the elephants have a trick that deals with that.
沉淀物都沉在底部
Sediment settles to the bottom,
而干净的水则浮在表面
and the cleaner, fresher water lies on the surface.
他们小心翼翼的从水面上掠过
They skim it carefully from the top.
然后用最轻柔的动作缓慢前进
Then, as gently as elephants can, they move forward slowly,
尽可能的不把水搅浑
trying not to disturb the stagnant layers.
但这珍贵的水源 也吸引了其他种群远道而来
But precious water like this draws in herds from far and wide.
在相互热情的问候中 所有的小心翼翼被毁于一旦
In the exuberance of a greeting all their careful work is undone.
当暴躁的动物因饮水的需要而聚集时
When bulls are forced together by the need for water,
怒火也一触即发
tempers can flare.
在每年的这个时候 食物和水源往往相距甚远
At this time of year, food and water can often be far apart.
因此 既然小象们都已经恢复了精神
And so, now that the little ones are refreshed,
大家族又得再次踏上寻找食物的征途
the family has to head off to find food.
他们所前往的奥卡万戈平原 此时依然干旱
The distant Okavango plains that they're heading for are still dry,
而旱情还在恶化
and getting even drier.
困在逐渐干涸水塘里的鱼儿奋力挣扎着
Trapped catfish struggle in a shrinking pool.
而炙热的阳光却不是他们唯一的敌人
And the burning sun is not their only enemy.
这种天赐良机吸引了数英里以外的鹰
An opportunity like this attracts eagles from many miles away.
通常 他们要潜入河里捕鱼
Usually, they dive and snatch fish from the surface of the water,
但这种大旱却减轻了他们的工作量
but in this drought they won't have to work so hard.
这是上天赐予的礼物
These are prized catches.
鹳鹳和豺挤了进去 抢些残羹冷炙
Marabou storks and jackals muscle in on the leftovers.
尽管鱼的数量非常可观
But even with this bounty of fish,
然而鹰的天性使他们更乐于盗窃别人的食物 而不是去自己捕捉
it's in an eagle's nature to steal a meal rather than catch its own.
而这些争端却是秃鹳的好机会
And all this squabbling gives the marabou a chance.
到手了!
Got it!
现在只有再次泛滥的大洪水才能拯救这些鱼
Only the return of the flood can save these fish now.
在水塘周围
All around these pools,
奥卡万戈平原上的草持续的枯萎死去
the grass on the Okavango plains continues to wither and die.
尽管叶子上还残留着少许养分
But there's still some nourishment left in the leaves,
也被百万张小嘴吸食殆尽
and millions of tiny mouths make the most of what remains.
白蚁咬断枯草 拽入地底
Termites chop the dead grass and drag it underground
喂养自己的种群
to feed their colony.
蚂蚁扮演着关键的角色
They play a crucial role,
因为它们能促使养分重归贫瘠的土地
helping to return nutrients to these poor soils.
但现在 他们却带走了最后一棵珍贵的绿草
But now, taking the last, precious grass,
只留下一地的尘土和黄沙
they leave dust and sand in its place.
在这草食动物四处分散的时刻
With the grazing animals dispersed far and wide,
肉食动物的生活则更加艰难
it's leaner times for predators here.
只有走投无路的美洲豹才会对箭猪下手
Only a desperate leopard would tackle a porcupine.
这只年幼的豹子却遇上了双重麻烦
This youngster is about to meet double trouble.
箭猪唯一能下口的地方 在下腹
The only place to get a bite is on their undersides.
但这两只箭猪团结一致 守望相助
But the porcupines work together to watch each others' backs.
这只美洲豹只能先把其中之一翻过来
The leopard will have to flip one over.
钉子般锋利的刺能轻易刺穿皮肤嵌入肉中
Pin-sharp quills can easily snap off and become embedded in flesh.
高防御武器还可以轻易变成进攻的武器
It's a highly effective defence that can also be turned into attack.
这是个血的教训
It's a harsh lesson,
但是只要一点好运在加上少许愈合的时间 并不会留下永久性的伤害
but with luck and a bit of healing time, there'll be no lasting damage.
两百英里外
Two hundred miles away,
生命之泉的水流已经到达了
the pulse of life-giving water has now reached the swampland
奥卡瓦戈河入口处的湿地
at the entrance to the Okavango.
在这里 纸莎草的花床像海绵一样 贪婪的吸收水分
Here, thick beds of papyrus act like a sponge,
减慢了水流的进程
slowing the water's progress.
注满湿地将耗时数月
The swamp can take months to fill,
此后 如果水源仍然充足
and only then, if there is enough water,
才能溢出湿地 使动物们赖以生存的平原回春
can it overflow and rejuvenate the plains on which the herds depend.
遥远的东边
Far to the east,
女族长已经带领家族来到了荒漠枯林
the matriarch elephants have led their families to desert woodlands.
看来这是个偏僻的地方... 丝毫没有食物的痕迹
It seems an odd place to come - there's no sign of food
也没有供小象乘凉的树荫
and there's little shade for the calves.
但大象却自有妙计
But elephants can do something unusual.
它们可以吃下并且消化 那些看起来枯萎了的树枝
They can eat and digest seemingly lifeless branches.
年轻的象需要学习 干树枝也是有营养的
The youngsters need to learn that dry sticks are nutritious,
而且树皮里含有水份
and that there is moisture in the bark.
但是只吃树皮 不能满足小象的需求
But bark won't feed the youngest calves.
它们一天需要喝15公升的奶
They need to drink 1 5 litres of milk a day,
所以象妈妈们不仅需要食物 还非常需要水
so their mothers desperately need water as well as food.
一只年轻母象已经精疲力竭了
Exhaustion has got the better of one young female.
但她不能休息太长时间
But she won't get the chance to rest for long.
距下一处水塘 可能还有30英里
The next waterhole could be 30 miles away,
整个象群得启程了
and the whole herd needs to get moving.
回到奥卡万戈平原
Back on the Okavango plains,
从残存的草丛中 升起一股烟
the last remnants of grass are going up in smoke.
对于驻留的食草动物来说 这是个坏消息
It's bad news for the few grazers that remain.
一些鸟还搜寻着四散奔逃的虫子
A few birds collect the escaping insects.
但是大火却将食草动物们推向绝境
But fires don't help those who need to eat grass here and now.
这正是奥卡万戈平原最凄凉的时候
The Okavango plains are at their most desolate.
然而 在沙漠里的
Yet, out in the desert,
象群正向这里走来
the elephant herds are heading towards them.
女族长带领她的家族 沿着难以辨认的小路
The matriarchs guide their families along the maze of trails
走向下一处水塘
to the next waterhole.