地球脉动（2006）

和大象一样
Like the elephants,
狮子也必须长途跋涉 寻找生存所需的食物
the lions must travel great distances to find enough to live on.
可是狮子并不是什么地方都能去的
But lions can't go everywhere -
它们不会试着爬过一座沙丘
they won't attempt to cross this field of sand dunes
长角羚很清楚这一点
and the oryx know it.
狮子必须耐心等待 长角羚离开安全的沙丘
The lions must wait for the oryx to leave the safety of the dunes,
因为它们最后总得寻找食物和水
which eventually they must to find food and water.
介时狮子就能伏击它们
And then the lions will ambush them.
大象找到了一些它们最喜欢吃的食物
The elephants have found some of their favourite food.
草是所有大象的主食
Grasses are the staple diet of all elephants,
但这群象却忙着挖掘草根
but this herd concentrates on digging up the roots,
因为草根中的营养和水分比茎干多得多
which have more nutrition and moisture than the stems.
这一举措在这个资源 严重匮乏的地方显得极为重要
It's the sort of behaviour that can make all the difference in a place of serious shortages.
然而所有这一切即刻就将发生改变
Yet all this can change in an instant.
许多沙漠的命运都由远方的雨水决定
The fortunes of many deserts are ruled by distant rains.
这些水来自100英里之外的山地降雨
This water fell as rain in mountains more than a hundred miles away.
它叫做“瞬时洪水”
It's known as a flash flood
之所以这么叫是因为 这些水可能仅仅流淌一天左右
and called that because the water may run for just a single day.
而且一年最多也只发生1～2次
It's an event that only happens once or twice a year at the most.
布满沙子的河床像是一张巨大的吸水纸
The sandy riverbed acts like a giant strip of blotting paper
水一边流淌一边被它吸去
sucking up the water as soon as it appears.
这里的每一寸土壤都已被河水润湿
But every square metre of soil moistened by this river
为生活在这里的动物们带来了生机
will increase the chances of survival for those that live here.
水坑里暂时填满了水
Waterholes are filled temprorarily.
非洲其它地方的大象每天都会喝水
Elsewhere in Africa elephants drink every day,
但这里缺水的现状
but the lack of water here
意味着沙漠里的大象 只能每隔四五天喝饱一回
means that desert elephants can only refill their tanks once every four or five days.
短短一周内 瞬时洪水浸润过的 土地上已长出了青草
Within a week the flash flood has produced a flush of green,
远远多于从沙丘返回的长角羚的需求
more than enough to draw the oryx out of the dunes.
这是它们仅有的积累食物储备的机会
It's a rare chance for them to build up their food reserves.
洪水也让狮子过上了好日子
The flood has made life easier for the lions, too.
这只长角羚的肉最多 能维持整个家族一星期左右
The flesh of this oryx will keep the family going for a week at the most.
此时 狩猎暂时变得容易许多 河道也穿上了一件绿装
But for a while the hunting will be easier, now that river channel has turned green.
狮子和长角羚的美好时光十分短暂
The good times for lions and oryx are brief,
但就是这些短暂的日子使它们 得以全年在沙漠中生活
but these are the short moments that make it possible to live in deserts the year round.
死亡谷是地球上最热的地方
Death Valley is the hottest place on Earth.
然而这个“火炉”也会因为水而发生改变
Yet even this furnace can be transformed by water.
一场大雨使得在地下沉睡了30多年的 种子迸发出生命的活力
A single shower can enable seeds that have lain dormant for 30 years or more to burst into life.
这里已有一个世纪 没有像现在这样开满鲜花
And there hasn't been a bloom like this one for a century.
死亡谷中的花期很短
The periods of boom in Death Valley are short.
但它们发生的次数 足以保证生命长盛不衰
but they're just frequent enough to keep life ticking over.
植物的突然兴盛是 所有沙漠动物都盼望的事
A sudden flush of vegetation is what every desert dweller waits for,
一旦发生 它们必须尽可能地利用它
and when it happens they must make the most of it.
好日子到来时 地球上没有其它物种 能像沙漠蝗那样迅速而又戏剧性地作出反应
There is no other species on the planet that responds as quickly and as dramatically to the good times as the desert locust.
在地下埋藏了20年的虫卵开始孵化
Eggs that have remained in the ground for 20 years begin to hatch.
沙漠蝗的若虫是跳跃能手
The young locusts are known as hoppers,
在这一阶段 它们还不能飞
for at this stage they're flightless.
它们循着萌发的草香寻找新的用餐场所
They find new feeding grounds by following the smell of sprouting grass.
一般说来 若虫需要 经过4周才能变成成虫
Normally it takes four weeks for hoppers to become adults,
但如果条件允许 譬如现在
but when the conditions are right as now
它们的生长过程就会切换到快车道
their development switches to the fast track.
当一个地方的植物即将吃光时
As the vegetation in one place begins to run out
长着翅膀的成虫便释放出信息素 即一些气味信♥号♥♥
the winged adults release pheromones - scent messages,
提醒蝗群中的其它成员它们应该动身了
which tell others in the group that they must move on.
蝗群合并之后
And when groups merge,
形成了一团蝗虫云
they form a swarm.
成虫每天的进食量相当于自己的体重
An adult locust eats its entire body weight every day,
而整团蝗虫云能消耗掉数百吨♥植物
and a whole swarm can consume literally hundreds of tonnes of vegetation.
它们必须不停地迁徙
They have to keep on moving.
沙漠蝗御风而行
The swarm travels with the wind -
这是最省力的飞行方式
it's the most energy-saving way of flying.
随着风向迁徙意味着 它们总是飞向低压地区
Following the flow of wind means that they're always heading toward areas of low pressure,
那里正是风雨交加的地方 植物定能生长
places where wind meets rain and vegetation starts to grow.
在飞行过程中
As they fly,
一团蝗虫云也会和其它蝗虫云汇合
swarms join up with other swarms
从而形成巨大的灾害 无数“瘟神”组成的大军绵延长达40英里
to form gigantic plagues several billions strong and as much as 40 miles wide.
它们将把一路上能吃的东西 全部吃得精光
They will consume every edible thing that lies in their path.
这是地球上最壮观的景象之一
This is one of planet Earth's greatest spectacles.
很少能看见如此大的规模
It's rarely seen on this scale
而且也不会持续多久
and it won't last long.
待到食物耗尽之时
Once the food is gone,
无数蝗虫拍打翅膀时的喧哗将不复存在 再次取代它的只是沙漠中呼啸的风声
the steady roar of a billion beating locust wings will once again be replaced by nothing more than the sound of the desert wind.