我们的星球（2019）

The longest migration made by any mammal.
‎幸运的是 它的孩子成长很快
Fortunately, her youngster is growing fast.
‎在每天200多升奶水的滋养下
Nourished by more than 200 liters of milk a day
‎这头一吨♥重的幼崽充满了活力
the one-ton baby is full of energy.
‎幸运的是 妈妈知道该去哪里放松
Luckily, Mother knows just the place for him to let off steam.
‎就是这里
And this is it.
‎泻湖中♥央♥的一个浅沙洲
A shallow sandbar in the middle of the lagoon.
‎显然这里是一处好地方
And it's clearly the place to be.
‎当潮水从浅滩上卷过时
As the tide rolls in over the shallow bank
‎就会产生温和的水流
it creates a gentle current
‎吸引来自泻湖对面的鲸鱼
attracting whales from across the lagoon.
‎这是幼崽第一次认识鲸鱼社会
It's the calf's first introduction to whale society.
‎它看起来有点害羞
And he seems a little shy.
‎最好还是贴近妈妈
Best stay close to Mother.
‎沙洲是一个好地方
The sandbar is a good place to practice the swimming skills
‎可以用来练习 ‎长途旅行所需要的游泳技能
he'll need for the long journey north.
‎水母顺流而行
Jellyfish are carried along with the current
‎但它逆流而上
but he swims against it.
‎将水流当做水下跑步机来锻炼体力
Using it like an underwater treadmill to build up his stamina.
‎每年有超过一千只灰鲸 ‎迁徙到这片泻湖
Every year, over a thousand gray whales migrate to this one lagoon.
‎但并不都是带着幼崽的雌鲸
But not all are females with calves.
‎很多大块头的雄性长途跋涉到这里
Many are large males that make the long journey here
‎以期找到一个伴侣
in the hope of finding a mate.
‎带着幼崽的雌性肯定没兴趣
Females with young are definitely not interested
‎但这不会阻止这只浪漫的雄性
though that doesn't put off this amorous male.
‎游走似乎只会鼓励它
And swimming away only seems to encourage him.
‎若是横跨半个地球才来到这里
Rejection is clearly hard to take
‎那拒绝显然是难以接受的
when you've traveled half the length of the planet to get here.
‎现在 它似乎很沮丧 ‎将怨气发泄到了幼崽身上
And now, he seems to take out his frustration on the calf
‎逼它下潜 离开水面
forcing him down, away from the surface.
‎终于 雄性理解了暗示
Finally, the male gets the hint.
‎这对母子是时候往北走了
It's time for the pair to head north.
‎自从三个月前来到这里
Since arriving three months ago
‎雌性的体重减少了三分之一
the female has lost a third of her body weight.
‎所以它必须开始长途跋涉 ‎回到它的捕食地
So now she must begin the long trek back to her feeding grounds.
‎它的孩子需要运气才能完成旅程
Her youngster will need luck to complete the journey.
‎三分之一的灰鲸幼崽
One in three gray whale calves
‎永远不会到达目的地
never reach their destination.
‎（大西洋 赤道）
‎地球的倾斜促成了所有迁徙
The Earth's tilt drives all migrations.
‎但在赤道附近 ‎即使倾斜的季节性影响不大
But even at the equator, where the tilt has little seasonal effect
‎也有一些动物一直在移♥动♥
there are some animals that are constantly on the move.
‎行军蚁
Army ants.
‎每只行军蚁每天 ‎都要跑相当于人类马拉松的路程
Every day, each runs the equivalent of a human marathon
‎以收集食物
in order to collect food.
‎这种蚂蚁专门捕食其他昆虫的幼虫
These particular ants specialize in capturing the larvae of other insects.
‎满载猎物的工蚁
Workers loaded with their prey
‎在其他工蚁的帮助下穿过落叶的缝隙
are helped to cross gaps in the leaf litter by others
‎形成蚁桥
forming living bridges.
‎信息素的轨迹将它们引向临时总部
Trails of pheromones lead them to their temporary headquarters.
‎一个营地
A bivouac.
‎完全由这种蚂蚁的尸体组成的巢穴
A nest built entirely from the bodies of the ants themselves.
‎藏在这堵活墙背后的
Hidden behind this living wall
‎是蚁群的指挥中心
lies the control center of the colony
‎蚁后和它最新的幼虫
the queen and her most recent young.
‎过去两周 整个营地都挂在这里
The whole bivouac has hung here for the last two weeks.
‎但情况即将改变
But that is about to change.
‎白天变成黑夜
Day turns to night
‎一个信♥号♥♥在整个蚁群中荡漾开来
and a signal ripples through the colony.
‎从营地深处传来一个化学信♥号♥♥
A chemical cue coming from deep within the bivouac.
‎信息很清楚
The message is clear.
‎是时候离开了
It's time to move.
‎这些小昆虫有着大胃口
These little insects have large appetites.
‎在清除了周围森林中的活体猎物后
And having cleared the surrounding forest of living prey
‎它们现在必须移♥动♥并寻找新的觅食地
they must now move and find new feeding grounds.
‎沿着一条主要的觅食路径
Following one of the main foraging trails
‎工蚁们运送新孵化的幼虫…
workers transport the newly hatched larvae...
‎而兵蚁则守卫在边缘地带
while soldiers guard the edges.
‎这个蚁群里可能有多达50万只蚂蚁
There could be as many as half a million ants in this colony.
‎任何一只都不会被留下
And none will be left behind.
‎它们在黑暗的掩护下行进的原因
The reason they proceed under the cover of darkness
‎现在变得明确起来了
now becomes clear.
‎蚁后正在移♥动♥
The queen herself is on the move.
‎它比其他任何个体都大
She's bigger than any other individual.
‎在过去的两周内
And for the past two weeks
‎它每隔一分钟左右都要产下一枚卵
she's been laying an egg every minute or so
‎因此它无法行动
and, therefore, unable to travel.
‎现在 随着繁殖任务暂时中止
Now, with her reproductive duties temporarily suspended
‎它能够转移到新的觅食地了
she's able to move to fresh hunting grounds.
‎这是它唯一一次在公开场合露面
This is the only time she's ever visible out in the open.
‎蚁后不是行军蚁部队里 ‎唯一重要的旅人
And the queen is not the army's only important traveler.
‎在每隔几年才发生一次的罕见事件中
In a rare event that only happens every few years
‎会出现超大幼虫 由工蚁搬运
supersized larvae appear, carried by the workers.
‎这些年轻的雄性会是未来的蚁后
These are the young males and future queens
‎它们马上就会离开这个蚁群 ‎建立它们自己的王朝
who will soon leave this colony and establish their own dynasties.
‎在日光重新降临之前 ‎行军蚁部队开始扎营
Before daylight returns, the army makes camp.
‎它们每晚都会继续旅行 ‎直到到达新的觅食地
They will continue to travel every night until they reach fresh hunting grounds.
‎那时候 蚁后将做好产更多卵的准备
By then, the queen will be ready to lay more eggs
‎为它的王朝增添更多工蚁
and add more workers to her empire.
‎（四月）
‎（北太平洋）
‎回到北边
Back in the north
‎距离灰鲸妈妈和它的幼崽
the mother gray whale and her calf
‎开始它们伟大的迁徙已经四个月了
are now four weeks into their epic migration.
‎自从离开后 ‎这个小家伙已经胖了一千多公斤
Since leaving, the youngster has put on over a thousand kilos
‎但它的母亲已经几个月没有吃东西了
but his mother hasn't eaten for months.
‎但它们还需要在海里赶很远的路
And there is still a lot of ocean to cover
‎灰鲸妈妈才能在白令海中享受盛宴
before she can begin her banquet in the Bering Sea.
‎它们沿海岸行进 靠视觉线索引导
They keep close to the coast, using visual cues to guide them.
‎它在过去30年间 ‎经历过很多次同样的旅行
She's made this journey many times during the last 30 years
‎现在与它第一次出发时已经大不相同
and a lot has changed since her first trip.
‎但它还是不会回避人类的关注
Still, she doesn't shy away from human attention.
‎而且幼崽似乎很喜欢出风头
And the calf appears to positively relish the limelight.
‎拥挤的加利福尼亚海岸 ‎与它们在墨西哥的避风港湾相比
The crowded Californian coast seems a million miles
‎似乎相去甚远
from their sheltered bay in Mexico.
‎从现在开始只会更忙
And it's only going to get busier from here on.
‎很快它们就到达了洛杉矶的港口
Soon, the pair reach the port of Los Angeles
‎这是北美最大的港口
the biggest in North America.
‎每年有近两千艘船舰使用这里
Nearly 2,000 ships use it every year.
‎持续的发动机噪音扰乱了水下声景
The constant engine noise disrupts the underwater soundscape
‎使灰鲸们迷失方向 增加碰撞的风险
disorientating the whales and increasing the risk of a collision.
‎在这些海域每年都有 ‎几十只鲸鱼死于船舰袭击
Scores of whales die every year in ship strikes in these waters.
‎这条灰鲸
This gray whale
‎就是其中不幸的一条
was one of the unlucky ones.
‎妈妈和幼崽避开了最忙碌的航道
Mother and calf have avoided the busiest shipping lanes.
‎但旅程最危险的部分就在前方
But the most dangerous part of the trip lies just ahead.
‎蒙特利湾
Monterey Bay.
‎35公里的开放水域
Thirty-five kilometers of open water.
‎贴近这里的海岸会耗费宝贵的时间
Staying close to the shore here would cost valuable time.
‎所以它把幼崽带到了海湾深处
So she leads her calf across the deep water of the bay.
‎但这是有风险的
But it's a risk.
‎它知道那里有什么
She knows what's out there.
‎它进入了潜行模式
She goes into stealth mode
‎停止它的定期呼叫
stopping her regular contact calls
‎尽可能少地浮出水面
and surfacing as infrequently as possible.
‎虎鲸
Orca.
‎杀人鲸
Killer whales.
‎它们非常了解这些水域
They know these waters well
‎它们正在觅食
and they are on the hunt.
‎母亲和幼崽被发现了
Mother and calf have been discovered.
‎成年灰鲸的重量是虎鲸是十倍之多
An adult gray weighs ten times as much as an orca
‎足够成为一个强大的对手
and can be a formidable opponent.