萨默塞特郡的芦苇地 A reed-bed in Somerset,
蜻蜓在清晨的阳光下闪闪发光 and dragonflies glint in the early morning sun.
它们要等翅膀干了才会飞起来 They won't take to the air until their wings are dry.
其它的则在大型公共栖息地过夜 Others have spent the night in large communal roosts
天气转暖时 它们缓缓爬上芦苇丛 and, as the day warms, they slowly climb up the reeds.
直到最后 Until finally
它们准备好了 they're ready.
所有的蜻蜓都是在淡水中从幼虫开始生命历程 All dragonflies begin their lives as larvae in freshwater
它们成年后 就在阳光下度过了唯一的夏天 before emerging as adults for their summer in the sun.
它们的飞行敏捷性是首屈一指的 Their flying agility is second to none.
几乎无人能及 Or almost none.
一只燕隼 A hobby.
这些小型猛禽在非洲过冬 These small birds of prey spend the winter in Africa
并计算它们抵达英国的时间 and time their arrival in Britain
利用了蜻蜓大量涌现的时机 to take advantage of this mass emergence of dragonflies.
但事情并不总是如它们所愿 But things don't always go their way.
蜻蜓轻轻一拍翅膀就能躲开 The dragonflies can dodge with a flick of their wings
所以燕隼把注意力转向了雌性蜻蜓 so the hobbies turn their attention to the female dragonflies,
她们正忙着在水面产卵 who are busy laying their eggs on the water's surface.
燕隼来得又快又准 The hobbies come in low and fast.
抓住了 Got her!
这场夏日奇观完全取决于一个条件 This summer spectacle is totally dependent on one thing.
淡水 Freshwater.
在英国和爱尔兰 Here in Britain and Ireland,
我们有世界上最美丽的河流和湖泊 we have some of the loveliest rivers and lakes in the world.
从苏格兰的湖泊到威尔士的瀑布 From the lochs of Scotland to the waterfalls of Wales.
从爱尔兰的香农河 From the great Shannon River in Ireland
到像威尔特郡这样的小白垩溪流 to small intimate chalk streams like this one in Wiltshire.
但是今天 不到一半的河流和湖泊 But today, less than half of our rivers and lakes
对大自然来说是健康的 are in good health for nature.
在这期节目中 我们将揭示淡水所扮演的关键角色 In this episode, we will reveal the crucial role that freshwater plays
供养着所有种类的野生动物 in supporting wildlife of all kinds.
淡水是自然界的命脉 Freshwater is the lifeblood of the natural world.
不列颠群岛有超过15万英里的河流 We have over 150,000 miles of rivers in the British Isles.
它们流经每一处景观 连接着我们所有的野生动物 They flow through every landscape, connecting all our wildlife.
水的旅程从山顶开始 The water's journey starts at the top of the mountains.
河流塑造了地貌 Rivers shape the landscape.
它们为众多不同的栖息地提供食物和水源 They feed and water a multitude of different habitats.
最后它们流入大海 And, finally, they enter the sea.
在苏格兰北部 And here in northern Scotland,
幽灵般的影子聚集在像这样的地方 ghostly shadows have gathered where they do so.
大西洋鲑 Atlantic salmon.
在海上漂泊了四年后 它们又回到了这条河 After four years at sea, they've returned to the very river
它们就是在这里孵化的 where they were hatched.
现在是春天 它们将在接下来的六个月里 It's spring, and they will spend the next six-months
奋力逆流而上到达繁殖地 battling their way up-river to their breeding ground.
但它们的数量之多引起了其他人的注意 But their great numbers have attracted attention.
宽吻海豚 Bottlenose dolphins.
一群海豚聚集在尼斯河口 A pod has gathered at the mouth of the River Ness.
潮水正在上涨 这时鲑鱼 The tide is rising, and this is when the fish
会试图进入河流 will try to enter the river itself.
鲑鱼可能超过一米长 难以下咽 The salmon may be over a metre long and difficult to swallow
但这些聪明的猎手仍然有时间 but these intelligent hunters still find time
玩弄它们的食物 to play with their food.
大量的鲑鱼游过一片朦胧的混合水域 Those salmon that get past them swim through a hazy mix of waters
最后到达新鲜的淡水河流 and at last reach the fresh.
从这一点来说 它们是淡水鱼 From this point on, they are freshwater fish.
它们的身体从里到外都在变化 Their bodies change, inside and out.
它们银色光泽逐渐暗淡 变成了一种更深的色调 Their sea-fresh silvery sheen dulls to a darker hue
这使它们在河床上伪装起来 that camouflages them against the riverbed.
但是河水很低 But the river is low.
除非下雨 否则它们不能再前进了 Until there's rain, they can go no further.
它们可能会被困在这里好几个月 They may be stuck here for months.
由于它们不再进食 保存能量是关键 As they will no longer eat, conserving energy is key.
终于下雨了 Rain at last.
河水上涨 鲑鱼就可以继续向上游移动 The river rises, so the fish can start moving further upstream.
低地的急流不费多大力气就能通过 The rapids of the lowlands are passed without much effort.
但事情很快开始变得更加困难 But things soon start to get more difficult.
鲑鱼越游越高 The salmon push on ever higher,
到达了旅途中最严峻的考验面前 before reaching the most demanding test on their journey.
这些瀑布有三米高 These falls are three metres high
超越鱼类的极限 and right at the fish's limits.
它们聚集在雷鸣般的水下 They gather beneath the thundering water.
有的练习跳跃 Some make practice leaps
评估最佳进攻角度 assessing the best angles of attack.
终于 时机成熟了 Finally, the time is right
现在真正的跳跃开始了 and now the real leaping begins.
它们用激流把身体弹射到空中 They use the white water to slingshot their bodies into the air.
没有任何一种鱼能像这条鱼那样越过那么高的瀑布 No other fish can clear waterfalls as high as this one.
有些撞上了岩石 Some crash into the rocks,
它们肌肉发达的身体发出的撞击声 the thud of their muscular bodies audible
甚至在水的咆哮之上 even above the roar of the water.
每年 到达河流的这个点的鲑鱼越来越少 Every year, fewer and fewer get to this point in the river.
回归的鲑鱼数量下降了70% Returning salmon numbers have fallen by 70%
仅仅过了25年 in just 25 years.
但那些已经来到这里的鱼以惊人的活力继续前进 But those that have got here push on with astonishing vigour.
到了深秋 幸存者终于到达了 By late autumn, the survivors finally arrive
它们传统的产卵地 at their traditional spawning grounds.
终于到了繁殖的时候了 It's time, at last, to breed.
雌性鲑鱼直接开始挖掘 The females get straight to work, digging their redds
砾石中的浅洼地 shallow depressions in the gravel.
这是它们产卵的地方 This is where they will lay their eggs.
雄鱼在产卵期的时候全身都是红色 The males, in full spawning colours
长出新的钩状颚 并守在雌性附近 and with newly-developed hooked jaws, wait close by.
一只雌性会释放成千上万的卵 A female releases thousands of eggs
其中一只雄性在卵出生时为它们受精 and one of the males fertilises them as they emerge.
历尽千辛 逆流而上的旅程 It's the culmination of a journey
现在终于落幕 against the flow and the odds.
整个冬季 鱼卵都将在砂砾中发育 The eggs will develop in the gravel throughout the winter
很快就会长成小鱼苗 and soon become tiny fry.
它们的心跳透过半透明的皮肤清晰可见 Their heartbeats visible through their translucent skin.
鲑鱼的回归将维持整个河流生态系统 The salmon's return will sustain the whole river ecosystem
在漫长的冬季 through the long winter months.
但它们需要寒冷清澈自由流动的水来茁壮成长 But they need cold, clear, free-flowing water to thrive,
由于气候变化、污染和水坝 and due to climate change, pollution and dams,
所有这些生长条件都难以满足 all are in short supply.
大西洋鲑鱼曾经在英国和爱尔兰很常见 Atlantic salmon were once common across Britain and Ireland,
但现在越来越局限于这些偏远的北部河流 but are now increasingly restricted to these remote northern rivers.
按照目前的下降速度 它们可能会 At the current rate of decline, they may disappear
在短短20年内从我们所有的河流中消失 from all our rivers in as little as 20 years' time.
这些鱼的后辈可能是来完成 The grandchildren of these fish may be the last
这段非凡旅程的最后一批 to make this astonishing journey.
离开了山脉的河流变宽变缓 The rivers, having left the mountains, widen and slacken.
在一些地方它们汇入湖泊 例如佩思郡的这个湖 In places, they enter lakes such as this loch in Perthshire.
但这里有别的东西可能会减慢它们的速度 But here something else may slow them.
河狸 Beavers.
400年前它们因毛皮而被猎杀至灭绝 400 years ago, they were hunted to extinction for their fur,
但现在它们被重新引入苏格兰 but now they've been reintroduced to Scotland
很快它们就确立了地位 and it hasn't taken them long to get established.
它们行业的迹象显而易见 Signs of their industry are easy to see.
它们最出名的是它们建造水坝的技术 They are best known, perhaps, for their skill in building dams,
这个家庭花了很多时间来确保它的水坝 and this family spends a lot of time making sure that theirs
状况良好 is in good shape.
大坝造就了一片巨大的湿地 The dam has created a huge wetland.
这是河狸建造的天堂 It's a beaver-built paradise
提供了充足的生存空间 that provides plenty of living space
和无限的食物 and unlimited access to food.
在每年的这个时候 树枝在移动只能意味着一件事 At this time of year, branches on the move can only mean one thing.
刚出生的小河狸 Newborn beaver kits.
在最初的几年里 这些幼崽将和它们的家人呆在一起 The kits will stay with their family for the first few years,
在出发寻找自己的领地之前 before setting out to find territories of their own.
苏格兰有超过250个河狸领地 There are over 250 beaver territories in Scotland,
现在它们被重新引入英格兰和威尔士 and they're now being reintroduced into England and Wales.
对于其它物种来说 河狸通过减缓河水流速 By slowing the river, the beavers create a rich habitat
创造了一个富饶的栖息地 for a whole range of other species.
食物链的顶端 Right to the top of the food chain.
鱼鹰 Ospreys.
干净的水仍吸引了各种野生动物 Still, clean water attracts all kinds of wildlife.
在多塞特郡的石南荒原上 On a heathland in Dorset,
蜘蛛网覆盖着池塘周围的灌木丛 spiders' webs cover the bushes surrounding a pond.
有一种特殊的物种生活在水的边缘 And one specialist species lives at the very edge of the water.
一只雌性筏蛛 A female raft spider.
她只有你的手掌那么大 但却是个致命的刺客 She's the size of your palm and a deadly assassin.
她用水面当网 She uses the surface of the water as her web
通过振动感应猎物的存在 and senses the presence of prey from its vibrations.
不错的开始 但现在是繁殖季节 A good start, but it's mating season,
如果要繁殖后代的话 她需要更多的食物 and she'll need much more food if she's going to breed.
一只水黾可能是个很好开胃小菜 A pond-skater could be a good snack.
但不容易被抓住 But it's not easily caught.
这么少的一顿饭几乎不值得费这个劲 Such a small meal is barely worth the effort
但她也能在水下捕猎 but she can also hunt under the surface.
在这里有更丰盛的食物 There are much bigger meals to be had down here.
龙虱幼虫 The larva of a diving-beetle.
它本身就是凶猛的掠食者 Itself a ferocious predator.
但它必须浮出水面才能呼吸 But it has to come to the surface to breathe
通过尾部的气管 through a tube in its rear.
这样就进入了蜘蛛的攻击范围 And that brings it within striking range of the spider.
终于有一顿真正的大餐了 At last, a real meal.
现在她有了寻找配偶所需的能量 Now she has the energy needed to find a mate.
她留下一根丝线 She lays down a thread of silk
掺有香味 laced with perfume
然后回到她最喜欢待的地方 before returning to her favourite spot.
没过多久另一只筏蛛就发现了踪迹 And it's not long before another raft spider picks up the trail.
一只雄性 A male.
它有一对如拳击手套般的器官 He has a pair of large boxing glove-like organs
叫做须肢 用来储存精子 called pedipalps in which he stores his sperm.
这就是它一直在找的东西 And this is what he's been looking for
一根直接通向她的丝线 a thread of silk that leads straight to her.
一旦靠近 它就在水面上敲击 Once close, he taps the water's surface
发出它要靠近的信号 to signal that he's about to approach.
它还没她最后一顿饭大 He's no bigger than her last meal.
现在走错一步 它就可能变成甜点 A wrong move now and he could become dessert.
她似乎能接受 She seems receptive.
机会难得 It's now or never.
小心翼翼地 Carefully does it.
它们以缠绕的腿交配 They mate in a tangle of legs
它用一根须肢来转移精子 and he uses one of his palps to transfer his sperm
放进她身体的一个囊里 她会把它保存起来 into a sac in her body, where she will keep it
直到她准备好使用它 until she's ready to use it.
雄蛛随即迅速撤离 The male then beats a hasty retreat
在她把它也吃了之前 before she makes a meal of him, too.
当河流到达它们旅程的中间阶段时 As rivers reach the middle stages of their journey,
它们的体积和能量都会增加 they increase in both size and power.
几千年来 正是它们的力量塑造了我们的地貌 And it is their force over millennia that has shaped our landscape.
在石灰岩地区 In limestone country,
淡水在地下凿出一条路 the freshwater carves its way underground.
英国和爱尔兰有数千英里长的洞穴 Britain and Ireland contain thousands of miles of caves,
包括卡文郡的这些 including these in County Cavan.
水滴造就了钟乳石和石笋 The dripping water builds stalactites and stalagmites,
就像这些牙齿聚集在一起做鬼脸 like these teeth coming together in a rocky grimace.
几个世纪以来 它创造出了各式各样的石柱和石帘 Over centuries, it can create all kinds of pillars and curtains.
但即使在这里也有生命 Yet, even here, there is life.
水鼠耳蝠白天栖息在洞穴里 Daubenton's bats roost in caves during the day.
夜幕降临时它们才开始觅食 And, as night falls, they head out to feed.
幽灵般的影子出现在星光闪烁的河流上 Ghostly shapes appear over a starlit river.
蝙蝠通过发出回声定位的叫声来导航 The bats navigate by sending out echolocation calls
如果我们放慢声音和图像的速度 我们就能看到它的运作 which we can watch in operation if we slow down both sound and picture.
很快就明白了为什么水鼠耳蝠 It's soon clear why Daubenton's bats
也被称为水蝠 are also called water bats.
它们在河上巡逻 利用缓慢流动的水 They patrol the river, searching for tiny movements on the surface
搜寻水面上的微小动静 of the slow-moving water.
它们用叫声的回声 They use the echoes from their calls
来锁定猎物 to lock on to their prey.
然后从水面抓走 And then skim it from the surface.
这些小蝙蝠重约8克 Weighing about 8g, these little bats can nearly double
它们的体重在一夜的狩猎中会增加一倍 their body weight in a single night's hunting.
在这个秋天的夜晚 And on this autumn night,
雄性尤其需要它们所能获得的所有能量 the males in particular need all the energy they can get.
一只水鼠耳蝠在林间空地盘旋 A Daubenton's bat circles in a woodland glade.
很快其它的也从树的 And it's soon joined by others emerging from a cave
底部洞穴中出来 at the base of a tree.
在它们的导航声中 有一种不同的声音 Amongst their navigational clicks, there's a different sound.
它们在互相呼唤 They are calling to one another.
随着它们数量的增加 它们的叫声也在增加 As their numbers increase, so do their calls.
很快 其他物种也来了 包括纳特勒的 Soon, other species arrive, including Natterer's
棕色长耳蝙蝠 and brown long-eared bats.
任何一个时间里最多可以有十个物种 There can be up to ten species at any one time,
在这漆黑的竞技场里旋转 whirling around in this pitch-black arena.
这是一个展示会场 This is a display ground
雄性蝙蝠竞相吸引雌性 where male bats compete to impress the females.
有些蝙蝠甚至跋涉40英里来到这里 Some of these bats have travelled over 40 miles to be here.
午夜时分 蝙蝠都消失在下面的洞穴里 Around midnight, the bats disappear back into the caves below,
它们很快就会在那里安顿下来并冬眠 where they will soon settle down to hibernate.
春天结束了另一种动物的冬眠 Spring brings the end of hibernation for another animal.
一只蟾蜍 A common toad.
这是一只母的 This is a female.
母蟾蜍需要淡水来产卵 Common toads need freshwater in which to lay their eggs,
所以她必须找到一个池塘 so she must find a pond
这可能需要几英里的路程 and that can involve a journey of several miles
道路充满了障碍和危险 which is full of obstacles and dangers.
今晚行动的可不止她一个 She's not the only one on the move tonight.
雄性蟾蜍另有目标 Male toads are also about.
它们在寻找雌性 They're in search of females,
当这只雄性找到一只时 它会紧紧地锁住她 and when this male finds one, he locks on tight.
但它的对手也有同样的想法 But his rivals have the same idea
然后是一场摔跤比赛 and then it's a wet-legged wrestling match
争夺最佳位置 to stay in prime position.
比赛结束了 奖金是免费搭便车 The competition is seen off and the bonus is a free ride.
但最大的挑战还在前面 But the biggest challenge lies ahead.
现在许多蟾蜍的传统迁徙路线是穿过公路 Roads now cross many of the toads' traditional migration routes
每年都有成千上万的蟾蜍被杀 and tens of thousands are killed every year.
成功了 Made it.
在过去的30年里 蟾蜍的数量 With toad numbers down by two-thirds
减少了三分之二 in the past 30 years,
在三月温暖潮湿的夜晚 我们应该注意下路面 we ought to be careful on warm, wet nights in March.
黎明时分 母蟾蜍和她的搭车者 At dawn, the female and her hitchhiker
终于到达它们旅程的终点 reach the end of their journey.
她小时候孵化成蝌蚪的那个池塘 The very pond in which she hatched as a tadpole.
它们直接进入正题 They get straight down to business
雌性会产下成千上万的卵 一串一串的 and the female produces thousands of eggs in long links of spawn.
如果雄性紧抓不放 它们会全部受精 The male, if he holds on tight, will fertilise them all.
几个月后 夏天到了 A few months later and summer is here.
这些小蟾蜍现在已经准备好进入下一个阶段 These tiny toadlets are now ready for their next stage.
它们必须前往陆地 They must head for dry land.
成年后的大部分时间里 它们将在树林里度过 They will spend most of their adult lives in the woods
也就是它们母亲的出发地 from which their mother emerged.
但要到达那里 它们必须穿过一个杀戮区 But to get there, they must cross a killing zone
被巨大的水蛭所困扰 haunted by giant leeches.
有些有15厘米长 Some are 15cm long.
而且它们对小蟾蜍很有胃口 And they have an appetite for baby toads.
它们用敏锐的嗅觉和五双眼睛搜寻 They hunt using a keen sense of smell and five pairs of eyes.
小蟾蜍要想到达树林就必须冒险前进 The toadlets must keep going if they want to reach the woods.
如果它们不够快 等待它们的命运是残酷的 If they're not quick enough, their fate is grim.
整个吞噬 Consumed whole.
水蛭可以用身体的任何一端抓住猎物 The leeches can grab with either end of their body
还有三副牙齿 and three sets of teeth.
小蟾蜍一旦被抓住就无路可逃 Once caught, a toadlet has no escape.
虽然有一两只被夺去生命 But for every one that is taken,
但有数百只安全逃到了树林里 hundreds make it to the safety of the woods.
对于大多数的小蟾蜍来说 这是一个有着快乐结局的恐怖故事 For most of these toadlets, it's a horror story with a happy end.
在不列颠群岛 我们有世界上最稀有 In the British Isles, we have one of the world's rarest
最美丽的淡水栖息地 and most beautiful freshwater habitats.
白垩溪 Chalk streams.
世界上只有200条左右 Only around 200 exist in the world
其中超过四分之三流经英国 and over three-quarters of those flow here in England.
凉爽、富含矿物质的水流 A reliable flow of cool, mineral-rich water
从下面的白垩层冒出来 bubbles up through the chalk below
并支撑着一个丰富的淡水群落 and supports a rich freshwater community.
河床上有东西在蠕动 On the riverbed, something stirs.
这只小昆虫在过去的两年里 This young insect has spent the last two years
掩埋在碎石中 buried in the gravel.
有强壮的前腿 羽毛状的鳃和流线型的身体 With strong front legs, feathery gills and a stream-lined body,
它非常适应水下生活 it's excellently adapted to life underwater.
但现在是五月下旬 一切即将改变 But it's late May, and everything is about to change.
当你只有2厘米长的时候 Even breaking through the surface is a challenge
即使是突破表面也是一个挑战 when you're just 2cm long.
最后当它的翅膀展开 Finally, as its wings unfurl,
这只成年后的雄性蜉蝣开始了 the little creature starts a new life as an adult
新的生活 a male mayfly.
它现在只剩下几天的生命了 He now has just a few short days to live,
所以它很快就为它的第一次飞行做好准备 so he quickly prepares for his first flight.
而且越快越好 And the sooner the better.
下面的鱼是第一个注意到这个春天的宝藏的 The fish below are the first to notice this springtime bonanza.
没过多久 水面上的动物也开始注意到了 And it's not long before those above water also get their eye in.
它需要升空 He needs to get airborne.
但这是刚从煎锅里出来 But it's out of the frying pan
又跳入火中 and into the fire.
至少蜉蝣的优势在于数量众多 At least the mayfly have the advantage of great numbers.
一周内就会有超过一百万只 In just a week, more than a million will emerge
仅这条河 from this stretch of river alone.
雄蜉蝣要做的第一件事就是向河岸游去 And the first thing the male does is head for the river bank.
蜉蝣在昆虫中是独一无二的 在它们完全成长之前 Unique among insects, mayfly undergo a second adult moult
经历了第二次成虫蜕皮 before they're fully mature.
它的一生都在为这一刻而努力 His whole life has been building to this moment.
它终于准备好了 And finally, he's ready.
它在河的上空高飞 He flies high above the river
加入了求偶之舞 and joins the mating dance.
和其它雄性一起起起伏伏 Rising and falling with the other males,
它展开尾巴炫耀自己的空中本领 he spreads out his tail, showing off his aerial prowess.
这些都是为了吸引雌性 It's all for the benefit of the females,
她们现在正从水下浮出水面 who are now emerging from the water below.
很快 河岸上到处都是交配的情侣 Soon, the river bank is alive with mating pairs.
每只雄蜉蝣都会继续跳舞 直到精疲力竭而死 Each male will continue to dance until he dies of exhaustion.
河岸上的小洞 A small hole in the river bank
是这条河上最神秘的居民之一的家 home to one of the most secretive of the river's residents.
鼩鼱 A shrew.
这个是母的 This one, a female,
和你的拇指差不多大小 is pretty small about the size of your thumb.
体型小意味着热量损失也快 Being small means she loses heat quickly
必须不停地进食 and must eat almost constantly.
三小时不进食可能是致命的 Three hours without food could be fatal
所以当岸上的食物不足时 so when supplies on the bank get low,
她必须到别处去找食物 she must find food elsewhere.
她是一只水鼩 She's a water shrew.
一开始她有点不情愿 She's somewhat reluctant at first.
因为在水下她会更快地失去热量 Underwater, she will lose heat even faster.
但当她需要冒险时 她必须这样做 But needs must, so when she does take the plunge,
她动作很快 she works at great speed.
在实际的情况下无法看清发生了什么 In real time, it's impossible to see what's going on.
但放慢速度后 可以看出她是多么适应 But slowing things down reveals how marvellously adapted she is
水下的环境 to the underwater world.
她脚上的硬毛就像脚蹼 Stiff hairs on her feet act like flippers
把尾巴变成了方向舵 and others on her tail turn it into a rudder.
她能闭着眼睛游泳 She swims with her eyes closed
展开的胡须帮助她感知猎物 fanning out her whiskers to help her sense her prey.
最值得注意的是 And, most remarkably,
她能闻到水中的气味 she can detect smells down here.
她放出微小的气泡 She lets out tiny bubbles of air
捕捉水中的气味颗粒 to pick up scent particles in the water.
这被称为嗅泡泡 It's known as bubble sniffing.
但使用这种技术意味着她很快就会耗尽氧气 But using this technique means she quickly runs out of air.
这一次 好在一切顺利 This time, everything comes together.
蜻蜓幼虫是一顿大餐 A dragonfly larva is a huge meal
但很难制服 but hard to subdue.
是时候使用她最后的武器了 It's time to use her final weapon.
鼩鼱是英国唯一一种唾液有毒的哺乳动物 Water shrews are the only mammal in Britain with venomous saliva.
所有的野生动物都在某种程度上依赖于淡水 All wildlife is dependent, to some extent, on freshwater.
但是在英国每条河流都被污染了 But here in England, every single river is polluted.
农业径流和人类排泄物倾倒 Run-off from farming and dumping of human waste
导致藻类大量繁殖 causes algae to bloom.
这会减少氧气 使植物窒息 This reduces oxygen, chokes the plants,
让野生动物赖以生存的河流退化 and degrades the rivers on which our wildlife depends.
当河流接近它们旅程的终点时 它们的速度会减慢 As rivers approach the end of their journeys, they slow,
芦苇床能够生根发芽 and beds of reeds are able to take root.
萨福克郡现在是冬末 Here in Suffolk, it's late winter.
赤鹿 Red deer.
这个广阔的区域是鲜为人知的庇护所 This huge area is a little-known winter refuge
英国最大的陆地哺乳动物就栖息于此 for Britain's largest land mammal.
鹿踏出的小路在芦苇丛中留下了痕迹 The paths the deer create make gaps in the reeds.
在开阔的水面上 And on the open water,
凤头鸊鷉 great crested grebes.
虽然是年初 It may be early in the year,
但它们的求偶之舞已经开始了 but their mating dance is already well under way.
作为序幕 鸟儿们摇着头 As a prologue, the birds shake their heads,
炫耀它们的羽毛和打扮 showing off their plumage and preening
确保它们的羽毛处于最佳状态 to make sure their feathers are in tiptop condition.
服装准备好了 开始上演第一幕 Costumes ready, act one reaffirms any bonds
重叙旧情 that were made in previous years.
单身的鸟儿呼唤着伴侣 Single birds call for a partner
摆出一种被称为猫态的姿势造型 before adopting a posture known as the cat display.
这是发出邀请 It's an invitation
再来个二重奏 for a duet.
似乎已经被接受了 It seems to have been accepted.
这对情侣步调一致 The pair are falling into step.
但是它们被一个对手打断了 But they are interrupted by a rival.
另一只雄鸊鷉也正在寻找伴侣 Another male is looking for a partner
双方展开激烈的争斗 and starts a sharp-beaked argument.
不过 结局还好 But all's well that ends well.
对手被赶走了 The rival is seen off
两人开始了二重奏的终幕 and the pair begin the final act of their duet
青草舞 the weed dance.
这些复杂的舞蹈加深了双方的情感纽带 These complex displays create a bond between the pair
促使它们在抚养后代时能够在一起 which will keep the two together as they raise their young.
几周后 第一只雏鸟出现了 A few weeks later, and the first chick appears,
紧接着是第二只 shortly followed by the second.
父母双方轮流照顾雏鸟 Both parents care for the chicks, taking turns to babysit
另一方寻找食物 while the other finds food.
它们甚至从自己的背上取下羽毛 They even take feathers from their own backs
然后喂给雏鸟 and feed them to the chicks
保护小肚子不受锋利的鱼骨伤害 to protect tiny tummies from sharp fish bones.
这种非凡的关怀行为 This extraordinary caring behaviour
取决于春天时建立的牢固的联系 depends on the firm bonds that were made back in the spring.
一起跳舞 相伴彼此 Grebes that dance together stay together.
这些年来 我们失去了大片的芦苇地 We have lost huge areas of reedbeds over the years,
受农业排水影响 drained for agriculture.
但最近的保护工作表明它们是可以恢复的 But recent conservation efforts have shown that they can be restored
并且非常迅速 remarkably quickly.
当河流汇入大海时 淡水的旅程就结束了 The journey of freshwater ends when rivers reach the sea.
在这里它们可能会形成巨大的泥滩 Here they may create vast mudflats.
加起来有2000多平方英里 Together, they constitute over 2,000 square miles
遍布我们的海岸线 of our coastline.
从上面看它们毫无生气 From above, they look lifeless.
但它们充满了机遇 But they are full of opportunities.
现在是低潮 有足够的空间觅食 It's low tide, and there is plenty of space to forage.
每年冬天数以百万计的候鸟从各地飞来 Every winter, millions of migratory birds from all over
由北半球到达我们河口补充体力 the northern hemisphere arrive in our estuaries to refuel.
但潮水已经转向 海水开始涌入 But the tide has turned and the sea starts rushing in.
餐馆要关门了 The restaurant is closing
鸟儿从泥里被赶了出来 and the birds are driven from the mud.
滨鹬是这里最常见的鸟 经常集体飞向天空 The most common birds here knot, take to the air en masse.
游隼从上方观察着 Watching from above, a peregrine.
它可能是地球上飞得最快的动物 It may be the fastest animal on the planet,
但它不慌不忙 but it won't be rushed.
它从高处俯视着鸟群 It surveys the flock from on high
然后收起翅膀 and then tucks in its wings
以每小时200英里的速度俯冲 and dives at speeds of up to 200mph.
滨鹬紧紧地靠在一起 The knot bunch tightly together.
在鸟群中间是安全的 There's safety in the middle of the flock.
游隼很难从中选择一只 It's difficult for the peregrine to select an individual bird
所以它改变了策略 so it changes its tactics.
飞低一点的话 更容易挑出一只单独的鸟 Coming in low, it's easier to pick out an individual knot.
用坚硬的泥土作为武器 Using the hard-packed mud as a weapon,
它会把受害者逼到撞向地面 it drives its victim into the ground.
只剩下一对受损的翅膀 The knot is left with a damaged wing.
但游隼会回来的 But the peregrine will be back.
每年冬天 游隼都会来到不列颠群岛的海岸 Every winter, peregrines come to the coasts of the British Isles
利用这个季节性的丰富资源 to take advantage of this seasonal bounty.
鸟群减少一员 The flock is reduced by one
但是当你有一支十万人的队伍时 but when you are 100,000 strong,
这只是一个很小的代价 that is a small price to pay.
现在潮水正涨到最高点 With the tide now at its highest,
鸟儿们安顿下来休息 the birds settle down to rest.
不列颠群岛在地球上的位置 The position of the British Isles on the planet
使得我们的河口在全球范围内都很重要 makes our estuaries globally important.
它们为来自世界各地的候鸟提供了 They provide vital refuelling stations for migratory birds
至关重要的补给站 from different parts of the globe.
在它从山到海的旅程中 On its journey from the mountains to the sea,
淡水滋养并恢复了自然界 freshwater has fed and refreshed the natural world.
它是我们狂野群岛的命脉 It's the lifeblood of our Wild Isles.
世界最伟大的奇观之一 One of the greatest spectacles
在不列颠群岛 in the British Isles
大西洋鲑鱼的迁徙 is the migration of Atlantic Salmon.
尽管它们的数量直线下降 Despite their numbers being in freefall,
淡水摄制组决心寻找新的方法 the freshwater team were determined to find new ways
拍摄这些令人惊奇的鱼 to film these astonishing fish.
它们的故事始于苏格兰东北部的因弗内斯附近 Their story begins near Inverness in north-east Scotland.
每年夏天 一群宽吻海豚聚集在海口 Every summer, a pod of bottlenose dolphins gather just offshore,
被大量鲑鱼吸引而来 drawn here by the salmon.
它们沿着一条狭窄的水道而来 They come along a very narrow channel that runs
就在海滩边上 just off the beach here.
海豚已经记了下来 The dolphins have clocked that
它们基本上就守在这条深水道里前端 and they can basically just sit off the point in this deep channel
等着鱼来 把它们一网打尽 and wait for the fish to come and just pick them off.
海豚只捕猎一个小时左右 The dolphins only hunt for about an hour,
所以船员们可以提前就位 so the crew get into position early.
但他们不是唯一的观众 But they're not the only ones.
很快就有成群的路人加入进来观看这一行为 Crowds of people soon join to see the action.
这是世界上最好的地方之一 This is one of the best places in the world
能离海岸这么近的地方看到这种景象 to see this behaviour so close to shore.
鲑鱼的下一个阶段是游到淡水中 The next stage for the salmon is to swim up into the freshwater.
在这里它们很紧张 对人极度警惕 Here, they're nervous and extremely wary of people,
所以几乎不可能用标准技术拍摄 so it's almost impossible to film using standard techniques.
但摄制组有锦囊妙计 But the crew have a trick up their sleeves.
水下无人机 An underwater drone.
这是另一个"可能会出什么问题?"的时刻 This is another, "What could possibly go wrong?" moment.
塔夫已经对这项技术进行了五年多的试验 Taff has been experimenting with this technology for over five years
认为这是进入鲑鱼世界的唯一途径 and thinks it's the only way to really enter the salmon's world.
即使现在 也不总是能按照计划进行 Even now, it doesn't always go to plan.
噢 Oh!
啊 不 一个螺丝掉了 Ah, no, one of the screws has gone.
我不可能找到那螺丝的 There is no way I'm going to find the screw.
喔... 你说什么? Oh, oh, oh! What?!
哦 你这小淘气 Oh, you beauty.
随着无人机的恢复和运行 With the sub back up and running,
摄制组开始记录鲑鱼的水下世界 the team begin to record the salmon's underwater world.
一窥这场非凡的迁徙 A glimpse into this extraordinary migration
很少有人见过 that few people have seen.
这是我见过最美的东西之一 One of the most beautiful things I've ever seen.
绝对令人着迷 Absolutely mesmerising.
鲑鱼面临的下一个 也是最大的挑战 The next and greatest challenge for the salmon
攀登三米高的瀑布 is ascending the three-metre waterfall.
拍摄鲑鱼在这里跳跃也是团队最大的挑战 Filming the salmon leaping here is the team's biggest challenge, too.
对于第一个镜头 相机需要定位 For the first shot, the camera needs to be positioned
就在瀑布正上方 directly above the falls.
这意味着需要将超过100公斤的装备放置到位 That means getting more than 100kg of kit into position
在四米高的咆哮水面之上 four metres above the roaring water.
鱼现在还没有跳 The fish still aren't jumping at the moment,
不过没关系 因为它们在等水位下降 but that's fine cos they're waiting for the water to drop.
希望在接下来的几个小时里它们会开始跳跃 Hopefully, in the next few hours, they'll start to jump
一旦它们开始了 应该会反复尝试 and once they do start, there should be repeated attempts of this.
新的摄像机位置有了回报 The new camera position pays off.
摄制组第一次拍摄到大西洋鲑的正面跳跃 The team film the salmon leaping head-on for the first time.
但有一个角度是塔夫多年来梦寐以求的 But there's one angle that Taff has been dreaming about for years.
我们要试试梦幻般镜头 We're going to try the dream shot
鱼实际上是从水下跃起的 the fish actually leaving the water from below.
好了 现在是揭晓真相的时刻 OK, so this is it. The moment of truth
好的 好的 我准备好了 OK. Yeah, yeah, I'm ready.
是啊 Yeah.
它出发了 Away she goes.
但瀑布下面的水流最大 Below the falls, the water flow is at its highest
让无人机和塔夫的技术面临巨大压力 putting the sub and Taff's skills under serious pressure.
你知道可能没有人看到过这种行为 You know, probably nobody's watched this behaviour,
但它们会先紧张观望 然后四处游动 but they nervously go and look at it, and then they go around
经过一系列试探 返回 and they do a little test and then they come back
然后开始跳跃 这绝对精彩 and then they go for it. Absolutely amazing.
拍摄鲑鱼这么多年来 这是我第一次看到这个 All these years filming salmon, it's the first time I've seen this.
这是第一次拍摄到鲑鱼从水下一跃而起 This was the first time salmon had been filmed leaping from underwater.
最后有几条鲑鱼成功突破河的顶端 Finally, just a few salmon make it to the top of the river.
回到了它们孵化成幼鲑鱼的地方 The place in the river where they themselves hatched as young salmon.
繁殖期的它们是最敏感的 When breeding, they are at their most sensitive,
而想要捕捉这些亲密时刻 需要一些无私的奉献 and getting these intimate moments needs some serious dedication.
除了圣诞节和节假日 我每天都拍 I'll film every day other than Christmas Day and Boxing Day
如果我妻子允许 我会在圣诞节那天拍摄 and I would film on Christmas Day if my wife would let me,
但她不让我这么做 but she does not let me do that.
我干这行大概有五年了 I've been doing this for about five years,
所以我们现在知道鱼将在何时何地产卵 so we know when and where the fish are going to spawn now.
关键是要知道它们在哪里 So, that's the key thing is knowing where they are.
随着产卵的完成鲑鱼的旅程也结束了 With spawning complete, the salmon's journey is done.
但对摄制组来说还有最后一部分 But for the crew, there's one final part of the story.
它们等了三年才等到完美的条件 And they've waited three years for the perfect conditions.
不是很优雅的着落 Not a very elegant slide,
但这真的很酷 but this is a really cool slide.
水獭滑道 An otter slide.
很明显附近就有一只 A clear indication there's one nearby.
水獭在白天通常非常难以捉摸 Otters are usually very elusive during the day.
这些寒冷的条件给了雷蒙德机会 These cold conditions gave Raymond his chance.
我能看到水獭在下游更远的地方 I can see the otter further downriver.
它刚刚从那边的冰架上出来 It's just come out onto the ice shelf on the side there.
它只会停留三四秒钟 It's only staying for, like, three or four seconds,
然后又回到水里 then it's back in the water.
这是一项艰苦的工作 It's hard work, this.
在旅程的最后 鲑鱼不仅为这只水獭 At the very end of their journey, the salmon not only provide
提供了急需的食物 a much-needed meal for this otter,
其垂死的身体 提供了丰富的营养 their dying bodies will provide essential nutrients,
滋养了河流的上游 enriching the upper reaches of our rivers.
鲑鱼曾在不列颠群岛的河流中随处可见 Salmon once swam in rivers throughout the British Isles
但在过去的25年里 in huge numbers, but in the last 25 years
从海上返回的鲑鱼下降了70% the number returning from the sea has dropped by 70%.
在英格兰和威尔士 形势已十分危急 In England and Wales, the situation is critical,
超过90%的鲑鱼种群面临灭绝的危险 with over 90% of salmon river populations at risk of collapse.
我们在所有这些不同的地方 Having filmed them in all these different places
不同的环境拍摄它们 and all these different environments,
这让我明白了 it's really brought home that, you know,
我们真的每一步都在干扰它们 we really are messing with them every step of the way.
我们的人造屏障阻断了它们的迁徙路线 Our man-made barriers block their migration routes.
城镇的污水 Sewage from towns and cities
农田的径流污染了我们的河流 and agricultural run-off from farms pollute our rivers,
这些使鲑鱼更容易感染疾病 making the salmon more susceptible to disease.
最重要的是 气候变化给它们带来了 On top of all this, climate change presents them
生存的巨大挑战 with even greater challenges.
干净没污染的水 这就是它们所需要的 They need cold, clean water. That's what they need.
而在很多领域 它们都没有得到 And a lot of areas, they're not getting that.
任何水温达到23度 它们就会停止进食 Anything over 23 degrees, they stop feeding,
一旦超过30度 它们就会在几分钟内死亡 and anything over 30, they die within minutes.
我们需要研究如何控制水温 We need to look at trying to manage those water temperatures.
如果我们能把栖息地带回来 And if we can bring that habitat back
实际上是重新野生化了这些河流 in effect, rewild those bits of rivers to put them
让鲑鱼回到健康的状态 to how they should historically have been, it's going to have
所有生态物种都会连带受益 a knock-on benefit for all the species that use the ecosystem.
鲑鱼是适应力很强的动物 Salmon are resilient animals.
如果我们能改善淡水的质量 If we can improve the quality of our freshwater,
消除其道路的障碍 remove barriers to its flow
更好地管理海洋问题 and better manage the challenges at sea
大西洋鲑鱼可能会再次兴盛 salmon could once more become abundant
穿越不列颠群岛 across the British Isles.
下一集 我们的海洋 Next time our ocean.
一个隐藏的世界 A hidden world
五彩缤纷 full of colour
和惊喜 and surprise.
英国开放大学制作了一张免费海报 The Open University has produced a free poster
探索我们的野生岛屿及其多样的栖息地和物种 exploring our wild isles and their diverse habitats and species.
通过致电订购您的副本 Order your copy by calling
或者登录bbc.co.uk/wildisles or go to bbc.co.uk/wildisles
然后点击链接进入开放大学 and follow the links through the Open University.
如果你愿意为恢复我们的荒野岛屿尽一份力 If you'd like to play your part in restoring our wild isles
了解更多关于你能做些什么 and learn more about what you can do to help,
在BBC网站上搜索Wild Isles just search Wild Isles on the BBC website.