自然界大事件（2009）

他们身上储备的脂肪 只够维持十天
The young have enough fat reserves to survive for just 1 0 days
在这段短暂的时间内
And in this brief window
他们必须自己学会飞行和捕食
they must learn how to fly and hunt for themselves
这是鲣鸟生命中最关键的时期
This is the most critical time in a gannet's life
失败就意味着饿死
Failure will mean starvation
为了准备他们的首次飞行
To prepare for their maiden flight
他们不断尝试着挥动翅膀 增强肌肉力量
they test their wings and strengthen their flying muscles
最终 饥饿驱使他们飞起
Eventually, hunger drives them onwards and upwards
一些幼鸟第一次就可以飞得又高又远
Some get up and away first time
但却有许多 没能越过汹涌的海浪
But many don't make it past the crashing surf
一些全身湿透的幼鸟 挣扎着回到岸上
Some bedraggled chicks struggle back to shore
而另外的一些 无法承受海浪的猛烈撞击
But for others, the pounding has been too much
这片栖息地上 只有少于半数的幼鸟
Fewer than half of all the chicks on this colony
能活过生命的最初三个月
survive their first three months of life
南非海岸线的生活是残酷无情的
The coast of South Africa is an unforgiving place
海豚宝宝依然依赖着它们的妈妈
The baby dolphins are still dependent on their mothers
他们要吃六个月的奶 直到像小鲣鸟一样
They suckle for six months before they, like the young gannets
不得不开始自己捕鱼
have to start fishing for themselves
洄游时 会出现大量的沙丁鱼
There is such an abundance of fish during the Sardine Run
就算幼崽也能捕到一些 并开始学习捕鱼技巧
that even the calves can catch some and so begin to learn their hunting skills
但今年的沙丁鱼洄游 也许根本不会发生
But the Sardine Run might not even happen this year
海豚暂时只能在茫茫大海中 不停地搜寻
For now the dolphins will have to continue to scour the vast ocean
回到岸上 一群小伙子们正为独♥立♥生活做准备
Back at the coast, other youngsters are getting ready to go it alone
南非软毛海豹也期待着 沙丁鱼群能向岸边靠拢
Cape fur seals are also waiting for the sardines to come close to shore
不过 海豹不太挑食
But seals have a broad diet
所以他们也不会放过其他到嘴的食物
so they can make the most of other feeding opportunities
直到沙丁鱼群进入捕食范围
until the sardines come within range
常有年轻的海豹 被成年雄性赶离栖息地
Young seals are forced from the colony by the dominant males
一旦被逐出 这些年轻的海豹会在岸边徘徊 寻找食物
Once they're cast out, the adolescents roam the coastline looking for food
对那些胖嘟嘟的鲣鸟幼鸟 他们是不会视而不见的
They won't turn their noses up at a plump young gannet
饥饿的海豹在海浪中巡游
Hungry seals patrol the surf
时刻准备攻击那些不能马上飞走的鸟
ready to pick off any birds that don't get airborne straight away
风力减弱的时候 鲣鸟幼鸟被困在了岛上
When the wind is light, the gannet chicks are stuck on the island
它们在这里真的安全吗?
Surely they're safe here?
即使在陆地上 海豹也可以用鳍以惊人的速度移♥动♥
But even on land the seal is surprisingly fast on his flippers
仅仅在这个栖息地上 这一个季节内
In this one season, on this one colony alone
海豹就可以吃掉多达一万只幼鸟
seals kill up to1 0,000 fledglings
然而 对于海豹而言 这些幼鸟只是
And, as ever, it all comes down to sardines
在沙丁鱼群到来之前的 开胃小菜
for the seals are only after the fish within the stomach of their victims
对于那些躲过海豹的幼鸟来说
For the young birds who do make it past the seals
依然有新的挑战
there are fresh challenges
向他们的父母学习各种技巧
Learning the skills of their parents
首先 他们需要找到猎物 沙丁鱼群
First they have to find their quarry, the sardine shoals
跟随追踪专家是最好的方法
And the best way to do that is to follow the expert trackers
他们饿坏了 父母的最后一次喂食在好几天以前
They're hungry. It's been days since their parents last fed them
随着搜寻的进行
As the search goes on
幼鸟学到了最复杂
the chicks are learning the most sophisticated
的生存技巧
survival technique of all -
如何利用其他生物的专长
how to harness the expertise of another species
在长时间的搜索后
After a long search
海豚发现了一小群鱼
the dolphins have found a small school of fish
它们将沙丁鱼驱赶到水面 进入了鲣鸟幼鸟的捕食范围
They drive the sardines to the surface and within range of the young gannets
现在 他们得迅速学会俯冲入水的技巧
Now, quickly, they have to learn the art of the plunge-dive
但是问题来了
But there's a problem
投机取巧的海豹也找到了鱼群
The opportunistic seals have found the fish, too
鲣鸟幼鸟面临一个棘手的抉择
The young gannets have a daunting choice
要么冒着面对敌人的危险潜下去 要么挨饿
To risk diving with the enemy or to starve
如果它们不尽快行动 鱼就会被吃光了
If they don't take their chances soon, there will be nothing left
这次它们很幸运
They're in luck
由于沙丁鱼重回海豹的菜单 海豹没有理会鲣鸟
With sardines back on the menu, the seals ignore the gannets
像往常一样 正当海豚完成了
As ever, the dolphins have done the hard work
聚集鱼群的苦差
of rounding up the fish
另一群捕食者赶来坐享其成
and now a host of other predators take advantage
鱼群每秒都在减少 竞争因此愈加激烈
With the shoal diminishing by the second, competition is fierce
但对于强大的闯入者来说 时间还有很多
But there is still time for a mighty intruder
布氏鲸一口吞下整个鱼团
The Bryde's whale devours the entire ball of fish
在沙丁鱼洄游正式开始之前
Until the Sardine Run starts in earnest
这些小冲突仅仅是序幕
these minor skirmishes are mere preludes to the main event
但是冬天终于要来临了 寒流向北方推进
But winter is finally on the way. The cold current pushes further north
冰冷的海水冲向岸边
This cool water forces its way up the coast
如果它继续向北流动
If it continues to flow northwards
沙丁鱼群也会随之而来
it will carry great shoals of sardines with it
捕食者们开始成群结队 翘首以待这场饕餮盛宴
The predators begin to gather, in anticipation of a feast
沙丁鱼不能忍♥受高于20度的水温
Sardines can't tolerate water above 20 degrees centigrade
所以 如果没有北上的寒流
So unless the cool water penetrates further up the coast
也就不会有一年一度的沙丁鱼洄游
the fish won't move and the annual run just won't happen
也许气候变化影响了这里
Perhaps climate change has made its mark here
此刻这片水域依然暖和 阻碍了鱼的行动
The waters have stayed too warm, stalling the movement of fish
沙丁鱼已经两年没有洄游了
There hasn't been a sardine run for the past two years
整个捕食队都沉寂了下来
The entire fleet is becalmed
一场冬季暴雨从南极席卷而至
A winter storm rolls in from the Antarctic
包围整个海岬 带来了冰冷的海水
battering the Cape, bringing cold water
为饥饿所驱使的鲣鸟
Driven by their hunger
在这种危险环境中 仍试图捕猎
gannets still try to hunt in these dangerous conditions
而事实上 这样的狂风暴雨
In fact, this wild weather
正是所有捕食者所期待的
is just what all the predators have been waiting for
对于他们来说 这是场完美风暴
For them, it's a perfect storm
它推动着冰冷的海水北上 形成狭长的寒流带
It has pushed a narrow tongue of colder water up the coast
随着寒流而来的 是一拨又一拨的沙丁鱼
This chilly current carries wave after wave of sardines with it
一侧是陆地 另一侧是暖水
Hemmed in by the land on one side and warm water on the other
被包围其中的沙丁鱼 踏入了一个陷阱
the sardines are being drawn into a trap
大自然跟这群不走运的鱼 开了一个残酷的玩笑
Nature is playing a cruel trick on these unfortunate fish
在这漫长的旅途中 它们将一无所获
as they'll get no benefit from their mass voyage
它们只是盲目跟随着寒冷的水流
They're slaves to the cold ocean currents
超过5亿的沙丁鱼正在游向灭顶之灾
More than 500 million fish are swimming towards disaster
但这只是沙丁鱼总数的十分之一
and yet this is just a tenth of the sardine population
洄游开始了
The run is on
前方 已布满埋伏
Ahead, an ambush is being prepared
当大海回归平静
As the seas begin to calm
海豚再一次锁定了沙丁鱼群
the dolphins relocate the sardine shoals
赶往岸边的海豚 一群群聚集了起来
As they track up the coast, the pods unite, combining forces
他们以难以置信的数量 组成了一支超级队伍
They form super-pods of incredible numbers
其中 有多达5,000只海豚
up to 5,000 dolphins in one group
他们迅速组成了一只地支球上
This is fast becoming one of the biggest groups of predators
最庞大的捕食团队
anywhere on the planet
进攻者们散开形成一条很宽的捕食带
The attackers spread out into wide hunting lines
延伸达一英里
stretching up to a mile across
其他的掠食者部队按老规矩 尾随海豚而至
Other divisions follow on, as ever tracking the dolphins
悄悄跟在最后的 是布氏鲸
Shadowing them all, the Bryde's whale
它们都在往同一方向进发
They're all heading in one direction
一个被称作瀑布崖的地方(南非海岸的绝壁景观)
towards a place known as Waterfall Bluff
这是海岸线的一个凹口 水流在这儿被打断
It's an arc in the coastline which interrupts the flow of currents
滞留着形成旋涡
trapping the water in a swirling eddy
而海豚知道 总有大量的沙丁鱼
And the dolphins know that the massive shoals
会被困在这个瓶颈地带
often get caught in this bottleneck
但这些沙丁鱼成功地避开了陷阱
But these sardines have managed to avoid the trap
第一批鱼群安全游到了瀑布崖的北部
The first shoals have been carried well to the north of Waterfall Bluff
把海豚大军抛在了身后
ahead of the dolphin super-pods
随着冷水带被挤压地更窄
As the cool water is squeezed into an ever thinner band
更靠近海岸
closer to the shore
鱼群被迫游入了浅水处
the shoals are forced up into the shallows
只有现在我们才能真正♥见♥识到鱼群的数量
Only now do we get a real sense of the sheer volume of fish
这批鱼群沿着海岸 绵延伸展15英里
This one shoal stretches along the coast for 1 5 miles
而15米深的水
The water is 1 5 metres deep
从上到下挤满了沙丁鱼
and packed with sardines from top to bottom
仅这一批鱼群的鱼 就可能超过了1亿条
There could be more than 1 00 million fish in this single shoal alone
只要沙丁鱼处于这样的浅水处
As long as the sardines are in such shallow water
它们就能免于海豚的捕食
they're beyond the reach of the dolphins
海豚会因害怕搁浅而停止尾随
who won't follow for fear of stranding
鲣鸟也不敢冒险俯冲到如此浅的水中
And the gannets can't risk diving into such shallow water either