美洲大陆（2025）

现在牠们终于能解渴了
Now they can get a drink at last.
精力恢复后
Fully revived
牠们又重操拿手本领
they're back to what they do best.
牠们对沙漠暗藏的危险却是了解甚少
What little they know of the dangers of the desert.
对蚂蚁来说
For the ants
雨水浸透的土地
the rain-soaked ground
正是牠们期待已久的
is exactly what they've been waiting for.
工蚁完成最后的飞行检查
The workers complete last-minute flight checks.
牠们准备好要起飞了
And they are cleared for takeoff.
几分钟内 数百对拍动的翅膀满天飞
Within minutes the air is filled with hundreds of fluttering wings.
终于能进行使命任务了
They can do what they were born to do.
在沙漠中建立新巢
Set up new colonies across the desert.
东方千哩处
A thousand miles to the east
便是北美大平原
lie the Great Plains
面♥积♥5亿英亩
covering 500 million acres
横跨10州
and ten different states.
落基山脉矗立其侧
They're flanked by the Rockies
使空气南北流动
which funnel air north and south
形成了美国风力最强的地区
creating the windiest place in the US.
当温暖的南风碰上寒冷的北风
When warm winds from the south collide with cold northerlies
怪物就此诞生
monsters are born.
雷暴
Thunderstorms.
强度是世界上数一数二的
Some of the most powerful in the world.
其能量可媲美一百颗核弹的总和
They can contain the same energy as a hundred nuclear bombs.
干旱草地瞬间起火
Dry grass is ignited in a flash.
中西部的火灾每年能烧毁 超过一百万英亩的土地
Fire in the Midwest can ravage over a million acres every year.
大火肆虐
And in its wake
改变了这里的生命
life here is transformed.
野火看似是灾难
Wildfires may seem like a disaster
事实上却造就了大平原的模样
but, in fact, they make the Great Plains what they are.
火灾防止了树木过剩
Fire prevents trees from taking over
并触发了自然重生的循环
and sparks off a natural cycle of rebirth.
这些草看似枯死了
The grasses may appear to be dead.
实则深入地底15呎以上
But by extending more than 15ft below the surface
根系依然活着
their roots live on.
这下草根能从灰烬中吸取养分
Now they absorb nutrients from the ash.
几周后
And within weeks
新生嫩草引来了饥肠辘辘的野牛群
fresh new growth attracts eager herds of bison.
美洲最大的陆生哺乳动物
The largest of America's land mammals
重达一吨♥
weighing in at a ton
肩高六呎
and standing 6ft tall at the shoulder.
广大牛群每年跋涉一千哩
Vast herds cover a thousand miles a year
寻找最鲜美的牧草
in search of the best grazing.
这些大块头对热量的需求极大
These beefcakes demand a lot of calories.
然而在南达科他
But here in South Dakota
这只老公牛没时间进食
this old male has no time to dine.
而是忙着靠打斗来获取交♥配♥机会
He's too focused on fighting for the chance to mate.
牠已为此掉了将近200磅
He's lost almost 200 lbs trying
仍然未能成功吸引雌性
and still no success with the ladies.
想确认雌性是否处于发♥情♥期的牠 一点也不低调
Confirming a female is in heat isn't subtle.
这可能是牠今年交♥配♥季的最后机会
She could be his last chance in this year's rut
因此牠决定守在雌牛身边
so he'll stay by her side.
不过牠将迎战一名挑战者
But she has competition from a rival
而且对方更年轻
and a younger one at that.
这只老公牛得站稳立场
This old bull needs to stand his ground.
若双方都不让步
If neither backs down
打斗就无可避免了
a brawl is inevitable.
牠俩势均力敌
They're closely matched
但老公牛善用地形
but the old bull uses the terrain to his advantage.
最终获胜
Victory.
赢得了雌性芳心
And with it, he does get the girl.
两百年前
Two hundred years ago
野牛数量约有六千万头
there were around 60 million bison.
在短短30年的过度捕杀后
After just 30 years of intensive hunting
一度仅剩不到千只
there were fewer than a thousand left.
如今牠们受到保护
Now they're protected
数量逐步回升
and with their numbers recovering
吸引了大量人群来观看其交♥配♥季
people flock to watch the rut.
但我们对大草原的影响其实更加深远
But we've had an even greater impact all across the prairie.
这片开阔平地很适合发展农业
The flat open land is perfect for agriculture...
尤其是大规模农业
on an industrial scale.
这里是美国的粮仓
It's America's breadbasket.
如今逾八成的北美平原都成了农田
More than 80 percent of all North American prairie is now farmland.
这个环境对多数野生动物着实不易
It's a difficult place for most wildlife.
但还是有些例外
But there are exceptions.
恐龙的后代
Descendants of dinosaurs.
内布拉斯加州的田野中
Here, in the fields of Nebraska...
沙丘鹤在北迁途中稍作停留
sandhill cranes make a pit stop on their migration north.
牠们每年造访这片大平原的惯例
They've been coming to this part of the Great Plains every year
自上次冰河时代结束后就已存在
since the end of the last Ice Age.
牠们旧的觅食地早已消失
Their ancient feeding grounds are long gone
如今却有新的契机可善用
but they've now taken advantage of a new opportunity
收成后剩下的玉米粒
corn kernels left over from the harvest.
夕阳西下时
As dusk falls
鹤群飞往夜间栖息地
the cranes head off to roost.
普拉特河
On the Platte River
密西西比河的一条支流
a tributary of the mighty Mississippi.
河道特别宽而浅
It's unusually wide and shallow.
对鹤来说相当理想
Perfect for cranes.
牠们能轻松地走进水中
They can wade right out into midwater.
使得郊狼无法偷偷靠近
So coyotes can't sneak up on them.
只能捡食因恶劣天气
They make do with the odd one
而丧生的零星少数
that succumbed to the elements.
鹤群停留时
While they're here
进入了求偶期
the courting season begins.
这只年轻雄鹤试图要展现自己
This young male is hoping to make an impression
雌鹤们也在打量牠
and the females are checking him out.
对鹤来说
For cranes
爱意
the language of love
由跳舞来传达
is dance.
牠成功吸引了一只雌鹤的目光
He's caught one particular female's eye.
若雄鹤的舞步打动了雌鹤
If his moves impress her
雌鹤就会依样画葫芦
she'll copy them.
整套动作以芭蕾般的优雅舞步作结
The routine builds to its balletic finale.
无论未来好坏
For better or worse
牠们将会相伴余生
they'll be together now for the rest of their lives.
时间可能长达30多年
And that can be over 30 years.
随着天色渐暗
As the light fades
越来越多鹤到此加入这场合唱
more and more birds arrive to join the chorus.
全球八成的沙丘鹤
Eighty percent of the world's sandhill cranes roost
栖息在普拉特河
on the Platte River.
数量超过五十万只
That's over half a million cranes.
这是地球上野生动物的奇观之一
One of the greatest wildlife spectacles on the planet
但在奇妙的狂野西部
but just another day in the extraordinary world
这天再平凡不过了
of the Wild West.
待续
谢谢观赏