地球脉动（2006）

智利的阿塔卡马沙漠
The Atacama in Chile.
这里是世界上最干旱的沙漠
This is the driest desert in the world.
有的地方可能连续5年不会下一滴雨
Some parts may not see rain for fifty years
既然有了这一纪录
and with such a record
不难想象这个地方定是彻底的荒芜
you'd expect the place to be completely barren.
这些是南美洲的骆驼——原驼
These are South America's camels, guanacos.
它们非常善于保存水分
They're very good at conserving moisture
但它们仍须定期补充水
but they nonetheless need a regular supply of water.
其中一部分水取自仙人掌花
They get it partly from cactus flowers
但这里又牵扯出另一个问题
but that explanation raises another question.
仙人掌为何能在这个无雨地带生存
How do the cacti survive without rain?
热浪抽干了地面上所有的水分
Hot winds suck all the moisture from the surface of the land.
显然 这里必须有其它东西 能代替雨水的作用
Clearly there must be something else that takes the place of rain.
答案就是一股与陆地平行的寒冷洋流
The secret is a cold sea current that runs parallel to the land.
冷水使得上方的暖湿气流冷却
The cold water cools the moist warm air above it
形成一团团的雾霾
and that produces banks of fog.
与此同时 吹向海岸的风将雾气带上陆地
At the same time wind blowing on to the shore sweeps the fog inland.
不久之后 雾凝结成了露水
Before long the cacti are dripping with dew.
雾经常会出现
The fog is so regular
就连喜湿的地衣也能在仙人掌上生长
that moisture loving lichens are able to grow on the cacti
它们像海绵一样吸收着水汽
and they absorb liquid like a sponge.
在一个几乎没有雨的地方
In the land of almost no rain
这些宝贵的水滴是许多动物的救命物资
these precious drops are life-savers for many different creatures.
在更远的内陆地区 空气一直十分灼热 水汽无法凝结
Further inland the air remains so warm that its moisture does not condense
因此这个狭长地带实际上是 阿塔卡马沙漠中唯一的生命绿洲
so this slender strip of desert is virtually the only part of the Atacama where life can exist.
如果没有雾
Without the fog,
这片土地也将成为不毛之地
this land, too, would be empty.
原驼尽量舔吮露水
The guanacos make the most of the dew
因为它们不会保留多久
but it will not remain for long.
1～2小时后 太阳将使它们蒸发
In an hour or two the sun will have burnt it off
仙人掌表面将回复干燥
and dry the surface of the cacti.
亚利桑那州的索诺兰沙漠 并不像阿塔卡马沙漠那样干旱
The Sonoran desert in Arizona is not quite so dry as the Atacama -
这里有时会下一些雨
some rain does fall.
可是降雨次数很少
But it is infrequent
一旦雨水到来
and when it does arrive
所有动植物都必须 做好准备尽量地利用它们
animals and plants have to be ready to make the most of it.
要下雨了
And it's coming.
当夏季季风吹来时
When the summer monsoon blows in
巨大的弁庆柱 ——一种世界上最大的仙人掌
the giant saguaros, one of the biggest of all cacti,
准备充分利用雨水
are ready to take full advantage of it.
暴风雨过后 弁庆柱 用又长又浅的根系吸收水分
After a rainstorm the saguaro's long shallow root system sucks up the water
茎上的皱褶使之能迅速膨胀
and the pleats on its trunk enable it to expand rapidly.
吸饱水后 弁庆柱的茎干中 已储存了5吨♥左右的水
When full, a saguaro stem can store up to five tonnes of water
这足以帮助它们度过几个月的旱季
and that's enough to see it through many months of drought.
这些立柱般的巨型植物 为橙腰啄木鸟提供了住所
The trunks of these huge plants provide homes for the gila woodpecker.
不过鸟并非唯一从仙人掌那里 获得好处的动物
But birds are not the only animals to benefit from the presence of the cacti.
在夏季的4个星期里
During four weeks of the summer
弁庆柱在晚上开花 吸引了不少拜访者
the saguaros bloom at night to attract visitors.
这些花中装满了花粉和花蜜
The pollen and nectar with which these flowers are loaded
吸引了长鼻蝠和长舌蝠
attract long-nosed and long-tongued bats.
蝙蝠数日前离开墨西哥以躲避酷暑
The bats left Mexico a few days earlier to escape the heat of summer
正向北飞往美国南部
and are on their way north to the southern United States.
要想到达那里 它们必须穿越索诺兰沙漠
To get there, they have to cross the Sonoran desert.
不过这片沙漠很大
But the desert is so big
它们一年中大部分时间都无法穿越这里
that for most of the year they would be unable to cross it.
现在 有了正在开花的弁庆柱
Now, with the saguaro in bloom,
它们便能在旅途中得到休整
they can refuel on the way.
看来弁庆柱进化出的 这种成功的储水方式
So the saguaro's success in developing a way to store water
如今已关系到大部分 在此生活和旅行的动物
is now crucial to most of the animals that live or even travel through this land.
缺少雨水的环境塑造了这些沙漠中的图标
The scarcity of rain determined the shape of this icon of the desert
尽管水很少 但它也和风一样 造就了各种地形
but water, scarce thought it is, has also, like the wind, shaped the land itself.
在犹他州的沙漠中
In the deserts of Utah
古老的河流冲开岩壁 不断拓宽这些峡谷
ancient rivers flowing across sandstone country steadily widen their canyons
直到把其间的土地削凿成 今天这样的尖峰和石塔
until now the land between them has been reduced to spires and pinnacles.
由于几乎没有土壤保留地表水分
With little or no soil to retain the water on the surface of the land
这里的生物极其稀少
life here is scarce indeed.
当资源有限的时候
And when resources are limited,
冲突自然不可避免
conflict is never far away.
这些是努比亚羱羊
These are Nubian ibex
它们正摆好架势准备激战
and they are squaring up for a duel.
冲突一旦爆发
And when trouble starts,
聪明的羱羊很清楚 最好的战术就是占领制高点
a smart ibex knows that the best thing to do is to gain higher ground.
这些其实是次级别的公羱羊
These are actually subordinate male ibex,
但它们的战斗依然十分激烈
but their fights are nonetheless serious.
失败一次或许意味着将永远失去生育权
Losing one might mean never getting the chance to breed ever.
同级别的参赛者在此公平竞争
When competitors are evenly matched as they are here,
决斗会持续一小时左右
duels can last for an hour.
高温下的战斗确实很耗费体力
In this heat the effort is trully exhausting.
但是这里的获胜者会获得重要的排名 一步步到达公羊排行榜的第一位
But victory here will gain important ranking points on a male's way to the top.
这类决斗非常危险
There's so much at stake
而且并不总是公平的
that not all play fair.
这场战斗已经分出了胜负
The battle has produced the winner,
但是最后的奖品仍然不属于它
but the ultimate prize is not his yet.
它通常属于拥有统治权的公羊
That currently belongs to the dominant male ibex.
它的地位为它赢得了一群忠诚的母羊
His rank earns him the loyalty of a harem of females
它们一起紧跟着它穿越沙漠
and they follow him closely as he travels across this desert
寻找水和食物
searching for foof and water.
它不必浪费时间寻找配偶
He doesn't have to waste time looking for mates -
它们都是它的妻子
they're his for the taking,
所以它要做的只是保证它们健康精壮
so he can concentrate with them on keeping fit and healthy.
蜥蜴是沙漠专家
Lizards are desert specialists.
在这里 它们的数量多得惊人
But here, their numbers are extraordinary.
非洲南部的这些岩缝中 容纳着世界上最大的蜥蜴群
These crevices in South Africa contain the highest density of lizards in the world.
它们叫做扁石蜥——因为显而易见的原因
They're called flat lizards for obvious reasons,
它们炫耀自己五颜六色的腹部 是为了争夺领地
and they flaunt their multi-coloured bellies in territorial disputes.
它赢了
He's made his point,
现在该是寻找食物的时候了
and now it's time to find some food.
随着白天气温的升高
As the day warms up,
蜥蜴离开它们藏身的岩缝
the lizards move away from their cracks
奔向峡谷底部
and head down to the bottom of the gorge.
它们的目标是这条小河
Their goal is the river.
河边没有一点食物
There is no food at the edge,
但是这条沙漠河流却藏着一个秘密
but this desert river holds a secret.
每天 成千上万的蚋从奔腾的河水中羽化
Each day blackfly rise from turbulent stretches of the river.
这就是蜥蜴到此的目的
This is what the lizards have come for.
蚋不会降落
The black fly never land,
所以蜥蜴必须跳起来捕食
so the lizards have to leap for their food.
每只身怀绝技的小蜥蜴 一天能吃掉50多只小虫
In one day each of these acrobatic little lizards may catch 50 flies.
尽管已有几百只蜥蜴在此捕猎 这里仍聚集着无数飞虫
There are plenty of flies to go round, even with hundreds of lizards competing for them.
在远离这些急流的地方 扁石蜥的数量则要少得多
Away from these rapids flat lizard populations are found much smaller numbers.
但在这里 一种特别的资源 带动了另一物种的兴起
But here one unusual abundance has produced another.
沙漠的形成是因为缺少水
Deserts are created by the lack of water,
可是这里杀死动物的 真正原因并非炎热和缺水
but what actually kills animals here is not heat or thirst,
而是缺少食物
but lack of food.
那么在地球上 如此巨大的植食动物是如何 在这个寸草不生的地方生存的呢
So how on earth does a plant-eater this size survive in a place apparently totally devoid of vegetation?
纳♥米♥比♥亚♥的大象是非洲最能吃苦的动物
Elephants in Namibia are the toughest in Africa.
它们必须如此
And they need to be.
仅有的少量食物也非常分散
What little food exists is so dispersed
所以这些大象每天得走上50英里
that these elephants walk up to 50 miles a day
沿着干涸的河床搜寻一些可以吃的东西
as they travel up the dry river channels searching for something to eat.
有时这个愿望看起来根本不可能实现
At times the task looks truly helpless.
大象似乎不属于有这种地形的地方
Elephants may seem out of place in this landscape,
但它们并非唯一意外的物种
but they're not the only ones.
奇怪的是 狮子也生活在这里
Amazingly, lions live here, too.
热带大草原的竞争促使鼎盛的 狮群数量达到20只 甚至更多
In savanah country huge herds of games support prides containing 20 lions or more.
而若想在此生存 狮子必须改变它们的习性
But to live here lions have had to change their habits -
狮群规模小了很多
prides are much smaller
但家族的疆土面♥积♥却大大增加
and their home ranges are very much bigger.
这里还有另一个问题
And there's an added problem -
它们的食物总是在移♥动♥
their food is always on the move.