0:00:04 > 0:00:06Britain.
0:00:06 > 0:00:08The history and the culture.
0:00:09 > 0:00:13Born of a landscape that we know and love.
0:00:13 > 0:00:15But, hang on a minute...
0:00:15 > 0:00:19That's just how WE see Britain.
0:00:19 > 0:00:23We humans are in a minority. We share our land and our shores here
0:00:23 > 0:00:26with hundreds of thousands of other species of animal,
0:00:26 > 0:00:30many of which have been here a lot longer than we have.
0:00:30 > 0:00:33So what I want to know is what they think of Britain,
0:00:33 > 0:00:34what matters to them?
0:00:38 > 0:00:44And that's my mission - to see the UK through our animals' eyes.
0:00:46 > 0:00:49Where are their favourite places in these crowded islands?
0:00:51 > 0:00:55How do their senses affect their view of our country?
0:01:00 > 0:01:02And what do they make of us?
0:01:02 > 0:01:03Off you go!
0:01:05 > 0:01:07I'm starting by diving into the lives
0:01:08 > 0:01:11of a hand-picked group of freshwater animals.
0:01:12 > 0:01:17I want to understand each one's unique abilities.
0:01:17 > 0:01:21And how freshwater animals have adapted to modern Britain.
0:01:24 > 0:01:27Together, they're going to reveal our country
0:01:27 > 0:01:29as we've never seen it before.
0:01:31 > 0:01:34Welcome to The Animal's Guide to Britain.
0:01:56 > 0:02:03Rivers, lakes, marshes, ponds, even ditches.
0:02:03 > 0:02:07Britain's freshwater habitats form a countrywide life support system
0:02:07 > 0:02:09on which all species depend.
0:02:17 > 0:02:21But the value of these places is greatest for the animals
0:02:21 > 0:02:22that actually live there.
0:02:29 > 0:02:30Now you may think
0:02:30 > 0:02:33that animals don't have much choice about where they live.
0:02:33 > 0:02:37But there's certainly one creature that does, because twice a year,
0:02:37 > 0:02:41it literally flies the length of the UK, sampling our lakes and marshes.
0:02:41 > 0:02:47So it's the perfect species to give us an insight into the quality of Britain's freshwater habitats.
0:02:56 > 0:03:03The osprey, a spectacular bird and a highly specialised fish hunter.
0:03:05 > 0:03:09Every spring, several hundred ospreys make the 3000-kilometre
0:03:09 > 0:03:12journey from West Africa to Britain.
0:03:13 > 0:03:16And most of them come here, to the Scottish highlands.
0:03:19 > 0:03:22Beautiful, isn't it?
0:03:22 > 0:03:23Very picturesque.
0:03:23 > 0:03:26This is Loch Garten and it's only a few hundred metres away
0:03:26 > 0:03:29from the ospreys' nest in the woods, there.
0:03:29 > 0:03:32So you would think that this would be the most convenient place
0:03:32 > 0:03:33for them to come and hunt.
0:03:33 > 0:03:35But they rarely, if ever, fish here
0:03:35 > 0:03:38because there aren't enough fish in here to warrant the effort.
0:03:38 > 0:03:41But luckily, they know somewhere better.
0:03:41 > 0:03:44And even luckier, I know it too.
0:03:47 > 0:03:51It's 5am and I've come to a much smaller loch where ospreys have
0:03:51 > 0:03:53often been seen hunting fish.
0:03:56 > 0:03:58Just donning some essential stealth.
0:03:58 > 0:04:04A couple of dark green mittens and then, and I can tell you,
0:04:04 > 0:04:10you won't have seen this on the catwalk this season. Oh!
0:04:10 > 0:04:14Oh, yeah. Just hope it works.
0:04:15 > 0:04:17Nothing's going to see me in this.
0:04:18 > 0:04:23For me, the prospect of seeing an osprey is always special.
0:04:23 > 0:04:24When I was a kid,
0:04:24 > 0:04:28these were rare birds, you know, they were super state secrets.
0:04:28 > 0:04:31No-one got the look-in as to where they were.
0:04:31 > 0:04:35You know, there was a privileged few in the RSPB who got to see them.
0:04:35 > 0:04:37The rest of us just saw them on the 9 o'clock news
0:04:37 > 0:04:40when they were being harried by egg collectors.
0:04:44 > 0:04:46RADIO: 'OK, on top of you now, Chris.'
0:04:46 > 0:04:49This is Keith, he's our osprey spotter this morning.
0:04:49 > 0:04:51'Female osprey from Loch Garten.'
0:04:51 > 0:04:53Look at that!
0:04:54 > 0:04:56Wow.
0:05:06 > 0:05:09'Three more birds coming up the river, there.'
0:05:14 > 0:05:19Unbelievable. Look at this, the sky. It's a flock - a flock of ospreys.
0:05:19 > 0:05:23In 40 years of birding, I've never seen this many ospreys,
0:05:23 > 0:05:26this close together, anywhere in the world.
0:05:29 > 0:05:31Wow...
0:05:33 > 0:05:35He missed.
0:05:36 > 0:05:39This is a brilliant place
0:05:39 > 0:05:42to get your head into that of a hungry osprey.
0:05:42 > 0:05:44They're clearly circling around the lake,
0:05:44 > 0:05:46looking through the surface for fish.
0:05:46 > 0:05:50They identify an area and then they seem to focus on it.
0:05:54 > 0:05:57This one's going in, it's going in, it's going. It's gone.
0:05:59 > 0:06:01It's got one.
0:06:02 > 0:06:04And it's got an antenna on its back,
0:06:04 > 0:06:07which means it's one of the study birds from Loch Garten.
0:06:12 > 0:06:16And that bird was carrying a fish in the classic osprey manner.
0:06:16 > 0:06:19Immediately after catching it, it swings it around
0:06:19 > 0:06:21so the fish is head-first
0:06:21 > 0:06:24into the direction the bird's flying, keeping it streamlined.
0:06:24 > 0:06:27It's tough enough work carrying a heavy fish anyway,
0:06:27 > 0:06:30but you don't want it flapping around underneath you.
0:06:30 > 0:06:31And to help them with this,
0:06:31 > 0:06:35one of their toes is opposable, so they can turn it round.
0:06:35 > 0:06:38So there are two toes on one side of the fish and two on the other.
0:06:51 > 0:06:52Got it!
0:06:55 > 0:06:57And one thing you see is that when they lift themselves out,
0:06:57 > 0:07:01they have a jolly good shake, to get that water off of their plumage.
0:07:01 > 0:07:04One thing that's immediately apparent here
0:07:04 > 0:07:06is how energetically expensive
0:07:06 > 0:07:09the process of catching fish is for these birds.
0:07:09 > 0:07:13They're using up lots of reserves.
0:07:13 > 0:07:17Maybe about one in four, they're going out with a fish.
0:07:19 > 0:07:23But the reason that this particular loch is so popular with ospreys
0:07:23 > 0:07:25is that this is a fish farm.
0:07:25 > 0:07:26It's heaving with prey.
0:07:33 > 0:07:37Amazing. Top 10 birding moment.
0:07:37 > 0:07:41A whole morning spent watching ospreys fishing.
0:07:41 > 0:07:46It's been absolutely remarkable. There's been only one downside.
0:07:48 > 0:07:49And that's dealt with that.
0:07:49 > 0:07:52My goodness me, the balaclava, never again.
0:07:52 > 0:07:56But you know, more than anything, it's given me the opportunity
0:07:56 > 0:07:59to get my head inside that of an osprey.
0:07:59 > 0:08:01And I think I've come up with a conclusion.
0:08:01 > 0:08:05It's not the pure water, it's not the climate up here,
0:08:05 > 0:08:08it's not the nesting trees. It's the fish.
0:08:08 > 0:08:12It's the fish that are the most important thing to these birds.
0:08:13 > 0:08:16But Britain has loads of fish.
0:08:16 > 0:08:19So why aren't ospreys everywhere?
0:08:20 > 0:08:24Well, once upon a time, they were.
0:08:33 > 0:08:38In medieval times, ospreys could be found from the Highlands of Scotland
0:08:38 > 0:08:40to the English south coast.
0:08:40 > 0:08:45They were believed to have to the mystical ability to hypnotise fish,
0:08:45 > 0:08:48which turned belly-up in surrender.
0:08:48 > 0:08:50They were held in awe by humans,
0:08:50 > 0:08:56featuring on the coat of arms of Swansea, granted 1316.
0:08:56 > 0:08:59Ospreys even enjoyed divine protection,
0:08:59 > 0:09:03listed in The Old Testament as an animal not to be eaten.
0:09:03 > 0:09:06They had it good.
0:09:06 > 0:09:11But then, around the 1500s, ospreys began fishing from human-made ponds,
0:09:11 > 0:09:15and the relationship soured.
0:09:15 > 0:09:19Later, the Victorian humans became obsessed with collecting rare eggs.
0:09:19 > 0:09:22The rarer the bird, the higher the demand,
0:09:22 > 0:09:26until, in 1916, the last osprey vanished from Britain.
0:09:29 > 0:09:33But, thankfully, that wasn't the end of the story.
0:09:33 > 0:09:37In 1954, a pioneering pair of ospreys,
0:09:37 > 0:09:43migrating from West Africa to Scandinavia, stopped at Loch Garten.
0:09:43 > 0:09:47They liked it so much they stayed to raise a family.
0:09:47 > 0:09:51As they struggled to survive, a nation watched in awe.
0:09:51 > 0:09:55Mr Watson, just how rare are these birds in Scotland?
0:09:55 > 0:09:56Well, as far as we know,
0:09:56 > 0:09:59they're the only pair nesting in the whole of Great Britain.
0:09:59 > 0:10:01Last year, they were robbed, unfortunately,
0:10:01 > 0:10:04and the year before this, one of the pair was shot.
0:10:04 > 0:10:09Ospreys were giving Britain a second chance and, this time,
0:10:09 > 0:10:14one group of humans was determined to protect them from egg collectors.
0:10:16 > 0:10:19This big clump of barbed wire is a pretty useful deterrent
0:10:19 > 0:10:21to anyone trying to get up to that nest.
0:10:21 > 0:10:25The electronic warning devices on the tree are rather interesting.
0:10:25 > 0:10:27They are vertical wires all round the trunk
0:10:27 > 0:10:31and anyone trying to climb the tree is almost bound to touch the wires,
0:10:31 > 0:10:34particularly if they're climbing it in the dark,
0:10:34 > 0:10:37because it is during the hours of darkness
0:10:37 > 0:10:39that we think an egg collector
0:10:39 > 0:10:43might try to raid the nest and collect the very valuable eggs.
0:10:46 > 0:10:49In the annals of British ornithology,
0:10:49 > 0:10:52this is an historic place.
0:10:52 > 0:10:56The hide, where veritable legions of bobble-hatted volunteers
0:10:56 > 0:11:00have guarded the oldest ospreys' nest in Britain.
0:11:00 > 0:11:03Established 1954.
0:11:03 > 0:11:04This is an honour.
0:11:06 > 0:11:10And in here, the history continues.
0:11:10 > 0:11:11Just look at this.
0:11:11 > 0:11:14Legend has it that these binoculars
0:11:14 > 0:11:17were requisitioned from a German U-boat.
0:11:17 > 0:11:19They're not marked with an osprey,
0:11:19 > 0:11:23but with a German eagle clasping a swastika.
0:11:23 > 0:11:27I'm rather hoping that I'm not going to spot a battle cruiser
0:11:27 > 0:11:30through here, but an osprey grasping a fish.
0:11:30 > 0:11:33And there is an osprey.
0:11:33 > 0:11:35That is one of this year's young
0:11:35 > 0:11:38that has fledged in the last few days.
0:11:38 > 0:11:43And it's sat there, having a bit of a preen,
0:11:43 > 0:11:46waiting for the adults to bring in a fish.
0:11:46 > 0:11:49This chick is an osprey success story,
0:11:49 > 0:11:52the fourth generation to be born at Loch Garten
0:11:52 > 0:11:55and one of around 100 chicks to have fledged here
0:11:55 > 0:11:58since they first came back in 1954.
0:11:58 > 0:12:02And many of these have gone on to nest across the Highlands.
0:12:02 > 0:12:05In fact, they've become part of the Scottish experience,
0:12:05 > 0:12:09along with lochs, monsters, haggis, tartan, you name it.
0:12:10 > 0:12:14But it's largely an accident that so many nest in Scotland.
0:12:14 > 0:12:18You see, ospreys keep returning here because they're creatures of habit.
0:12:18 > 0:12:22They prefer to nest near the place they were born or,
0:12:22 > 0:12:24at least, close to other ospreys.
0:12:25 > 0:12:29But ospreys have gradually spread out from their Loch Garten home.
0:12:29 > 0:12:33And now, some humans are trying to encourage them
0:12:33 > 0:12:35to go much further south.
0:12:35 > 0:12:38You can't get much further south than this, in the British Isles.
0:12:38 > 0:12:39That is Poole Harbour
0:12:39 > 0:12:43and I'm standing in Dorset on the RSPB's reserve at Arne.
0:12:43 > 0:12:46And the locals here have got a big idea.
0:12:46 > 0:12:49They want ospreys to nest here.
0:12:49 > 0:12:53After all, Poole Harbour is full of fish
0:12:53 > 0:12:57and ospreys regularly pass over Poole on their way back from Africa.
0:12:58 > 0:13:00But from an osprey's point of view,
0:13:00 > 0:13:03what's missing is other ospreys' nests.
0:13:04 > 0:13:10So the RSPB are putting up what you might call show nests,
0:13:10 > 0:13:13and I'm here to find out what an osprey needs in a nest.
0:13:13 > 0:13:17Do you know what I thought when I saw this nest from the ground?
0:13:17 > 0:13:19I know. It wasn't very high! I thought that as well.
0:13:19 > 0:13:23For the osprey, is that going to be high enough? It's perfect.
0:13:23 > 0:13:25What the osprey are looking for
0:13:25 > 0:13:30is a really isolated tree, nice and high, with a good vantage point.
0:13:30 > 0:13:34OK. Well, let's get some more twigs up and try and make it look
0:13:34 > 0:13:36a little bit more attractive.
0:13:38 > 0:13:42The thing is, everyone thinks a big pile of twigs is easy to build.
0:13:42 > 0:13:45But birds do a remarkable job, don't they, of weaving them in and out?
0:13:45 > 0:13:47They do. They definitely do.
0:13:47 > 0:13:50Yes, ospreys know what they're doing.
0:13:50 > 0:13:53The males do the heavy construction work,
0:13:53 > 0:13:58bringing back up to 100 loads of dead wood every day.
0:14:00 > 0:14:01Females, on the other hand,
0:14:01 > 0:14:05focus on the comfy bits, like the moss to keep their eggs warm.
0:14:06 > 0:14:08So what other desirable features
0:14:08 > 0:14:11would a house-hunting osprey be looking for?
0:14:11 > 0:14:13Erm, I think we can go for the pooh now.
0:14:13 > 0:14:16Pooh? Not literally.
0:14:16 > 0:14:18Can we have pooh paint, please?
0:14:21 > 0:14:25Well, I think we've, we've really poohed the nest. Yep.
0:14:28 > 0:14:30I'm beginning to understand
0:14:30 > 0:14:35what an osprey looks for, but this nest needs one final touch.
0:14:35 > 0:14:39This is a very fish-filled osprey, if ever I've seen one. Oop.
0:14:42 > 0:14:45Oh, my goodness. Oh, my goodness. That...
0:14:45 > 0:14:47He's a beauty.
0:14:47 > 0:14:49Right, OK.
0:14:49 > 0:14:52I thought everything was going so well with your plans.
0:14:52 > 0:14:55Have to hope for a very short-sighted osprey.
0:14:55 > 0:14:58From a distance, they actually do look quite convincing.
0:14:58 > 0:15:01And, of course, looking out there, we don't have to look far,
0:15:01 > 0:15:04do we, to see an amazing source of food for them?
0:15:04 > 0:15:07That's got to be full of flat fish and mullet, which they love eating.
0:15:07 > 0:15:08Yep, it's perfect.
0:15:08 > 0:15:12This sort of habitat, they'll be able to get more young off, hopefully,
0:15:12 > 0:15:15be a lot more successful here than they already are in Scotland.
0:15:26 > 0:15:28To an osprey checking out Britain,
0:15:28 > 0:15:30these artificial nests are a nod and a wink
0:15:30 > 0:15:33that this IS a good place to breed.
0:15:33 > 0:15:38And it's working. Human-built nests are popping up across Britain,
0:15:38 > 0:15:41and ospreys are spreading south.
0:15:41 > 0:15:45And if humans continue to make these magnificent birds welcome,
0:15:45 > 0:15:49ospreys will once again see the whole of Britain
0:15:49 > 0:15:52as a top spot to raise their young.
0:15:57 > 0:15:59It's easy to be impressed
0:15:59 > 0:16:04by dramatic lochs and lakes and cascading mountain streams.
0:16:04 > 0:16:08Not all of us, though, have these sorts of things on our doorstep.
0:16:08 > 0:16:09But what we can have
0:16:09 > 0:16:13is a very important freshwater wildlife habitat.
0:16:13 > 0:16:17It can come in the form of marshes, perhaps village ponds,
0:16:17 > 0:16:19or even our garden ponds.
0:16:19 > 0:16:21And when you think about it,
0:16:21 > 0:16:23if you were to add all of these things together,
0:16:23 > 0:16:27they'd become an incredibly important resource for wildlife.
0:16:27 > 0:16:30And I wouldn't mind betting that on each and every one of them,
0:16:30 > 0:16:34there's a species of one of nature's most miraculous insects.
0:16:44 > 0:16:46Dragonflies.
0:16:46 > 0:16:49Superbly adapted aerial predators.
0:16:51 > 0:16:56Some species can fly at 40 miles an hour! Others can even fly backwards.
0:16:56 > 0:17:03They can hover and bother any aerial insect with a diabolical deadliness.
0:17:03 > 0:17:04Imagine you're a little blue bottle.
0:17:04 > 0:17:08You fly out over the pond, flashing your iridescent blue bottom.
0:17:08 > 0:17:12You get spotted by the giant compound eyes of the dragonfly.
0:17:17 > 0:17:21It seizes you, snips off your legs and your wings,
0:17:21 > 0:17:24and by the time they've fluttered down onto the lily leaves,
0:17:24 > 0:17:28the assassin is already looking for its next victim.
0:17:30 > 0:17:34I think we can see dragonflies as a triumph of evolution.
0:17:34 > 0:17:36I mean, when you think about it,
0:17:36 > 0:17:40their body form has been virtually unchanged for millions of years.
0:17:40 > 0:17:43And their beginnings can be traced in Britain.
0:17:53 > 0:17:55The story of the British dragonfly
0:17:55 > 0:17:58goes back to a time long before humans,
0:17:58 > 0:18:02and before our islands even existed.
0:18:02 > 0:18:04This is the cast of a fossil
0:18:04 > 0:18:08that was recovered from the Bolsover coalmine in Derbyshire.
0:18:08 > 0:18:11And it shows the wing of a dragonfly.
0:18:11 > 0:18:15This is about 320 million years old.
0:18:15 > 0:18:19And this insect would have had a wingspan of about 20 centimetres.
0:18:19 > 0:18:22Others that lived with it had wingspans of up to 50 centimetres.
0:18:22 > 0:18:25And they were able to get this big because
0:18:25 > 0:18:27there was more oxygen in the air.
0:18:27 > 0:18:30It's incredible to think, isn't it, that this thing would have been
0:18:30 > 0:18:35flying around a full 150 million years before birds?
0:18:36 > 0:18:39But what about more recent times?
0:18:39 > 0:18:42Well, they've had their share of human prejudice.
0:18:45 > 0:18:48In The Middle Ages, dragonflies were associated with evil.
0:18:48 > 0:18:51Humans believed them to be in cahoots with snakes
0:18:51 > 0:18:53and able to wake them from the dead.
0:18:57 > 0:19:01A folk tale tells of the Devil turning St George's horse
0:19:01 > 0:19:03into a giant evil dragonfly.
0:19:05 > 0:19:09Humans also believed that women who scolded their husbands
0:19:09 > 0:19:13and men who cursed, might have their mouths sewn shut
0:19:13 > 0:19:15by a Devil's darning needle.
0:19:16 > 0:19:20Perhaps such a sinister reputation isn't surprising.
0:19:21 > 0:19:25But what do dragonflies see in Britain?
0:19:26 > 0:19:29Dragonflies are extremely accomplished aerial predators.
0:19:29 > 0:19:34And because there's an abundance of good quality aerial insect prey
0:19:34 > 0:19:35across much of Britain,
0:19:35 > 0:19:38they've managed to colonise just about every corner of it.
0:19:38 > 0:19:41But the story is a little bit more interesting than that,
0:19:41 > 0:19:45and if we look at the distribution of individual dragonfly species,
0:19:45 > 0:19:49because each of Britain's 24 species of dragonfly
0:19:49 > 0:19:52has a very different view on where to live.
0:19:59 > 0:20:02Some species are common and widespread,
0:20:02 > 0:20:07such as the Four-Spotted Chaser and the Emperor.
0:20:09 > 0:20:13But others are very picky, such as the Common Clubtail,
0:20:13 > 0:20:17which actually isn't common at all, apart from on a few rivers in Wales.
0:20:19 > 0:20:21And then there's the Norfolk Hawker,
0:20:21 > 0:20:24which is only happy on the Norfolk Broads.
0:20:24 > 0:20:27But to understand why different dragonflies prefer
0:20:27 > 0:20:29different parts of Britain,
0:20:29 > 0:20:33we have to enter the weird world of the dragonfly.
0:20:34 > 0:20:38If you take a look around the edge of this pool,
0:20:38 > 0:20:41down in amongst the emergent vegetation,
0:20:41 > 0:20:45you might find something which is utterly remarkable, truly bizarre
0:20:45 > 0:20:47and provides us with a real clue
0:20:47 > 0:20:52as to why dragonflies need very particular habitats.
0:20:53 > 0:20:56This is a dragonfly larva,
0:20:56 > 0:21:01the form in which a dragonfly spends most of its life.
0:21:03 > 0:21:06They're terrors of the underwater world,
0:21:06 > 0:21:09equipped with one of nature's most vicious weapons.
0:21:11 > 0:21:16A double-hinged jaw that flips forward to impale its prey
0:21:16 > 0:21:19in just two hundredths of a second.
0:21:26 > 0:21:31Despite its ferocity, the larva is very sensitive to its surroundings.
0:21:31 > 0:21:35It needs particular varieties of plants and prey,
0:21:35 > 0:21:40along with the right levels of oxygen and acidity in the water.
0:21:44 > 0:21:46Only if these things are right
0:21:46 > 0:21:51will it grow and then one day venture out of its watery nursery
0:21:51 > 0:21:55to make one of nature's most incredible transformations.
0:22:25 > 0:22:27So, when it comes to the distribution
0:22:27 > 0:22:30of the UK's dragonfly species,
0:22:30 > 0:22:33it's actually down to the tastes of their larvae.
0:22:33 > 0:22:36It's that that governs where these dragonflies live.
0:22:41 > 0:22:45This is a White-faced Darter, a superb dragonfly.
0:22:45 > 0:22:48It's a male, and you can see clearly here how it got its name.
0:22:50 > 0:22:53Apart from its face, it's dark-coloured
0:22:53 > 0:22:55so it can warm up quickly,
0:22:55 > 0:22:58making it well-adapted to the cool British climate.
0:23:01 > 0:23:05But one thing that might strike you as unusual about this species
0:23:05 > 0:23:08is that you can only find it in five sites in England,
0:23:08 > 0:23:13the most southerly of which is here, at Chartley Moss. But why?
0:23:13 > 0:23:15Well, this corner of Staffordshire
0:23:15 > 0:23:20has exactly the conditions that a White-faced Darter larva needs,
0:23:20 > 0:23:24and here is what makes this place so special.
0:23:24 > 0:23:27Whilst it might look like a piece of old heathland,
0:23:27 > 0:23:30I can tell you that, with no divine capabilities,
0:23:30 > 0:23:33I'm walking across the surface of a lake.
0:23:33 > 0:23:37Only the good news for me is that it's an underground lake.
0:23:37 > 0:23:41Look at this, you can see the ground rippling underneath me.
0:23:41 > 0:23:44And here, the cover is just about a metre of sphagnum
0:23:44 > 0:23:48and then 16 metres of...water.
0:23:48 > 0:23:49Yeah, that's quite enough.
0:23:52 > 0:23:56It's covered with a thick layer of this stuff,
0:23:56 > 0:24:01sphagnum moss, a hugely absorbent species.
0:24:01 > 0:24:03Just look at the amount of water
0:24:03 > 0:24:05that I can squeeze out of just one handful.
0:24:06 > 0:24:09But sphagnum isn't just highly absorbent.
0:24:09 > 0:24:11It also makes the water acidic
0:24:11 > 0:24:15and this is perfect for the White-faced Darter larva.
0:24:16 > 0:24:19What's peculiar about White-faced Darter larvae
0:24:19 > 0:24:21is they're not very good with predators.
0:24:21 > 0:24:25Rather than freeze when they're approached and avoid detection,
0:24:25 > 0:24:29they try to wriggle away, and fish in particular gobble them up.
0:24:29 > 0:24:34But the water here is way too acidic for fish,
0:24:34 > 0:24:36so there are no predators in it.
0:24:36 > 0:24:41And furthermore, the White-faced Darters don't live in the open pool,
0:24:41 > 0:24:45they avoid competition with all of the other dragonfly larvae
0:24:45 > 0:24:47by living in amongst the sphagnum moss.
0:24:47 > 0:24:52They could even be under my feet right now.
0:24:52 > 0:24:54So, for White-faced Darter dragonflies,
0:24:54 > 0:24:56this is heaven.
0:25:00 > 0:25:05Hmm, the only problem is, this type of acid heaven is disappearing.
0:25:08 > 0:25:14Over the past 40 years, humans have dug up 95% of acid peat bogs,
0:25:14 > 0:25:16mainly to make garden compost.
0:25:19 > 0:25:23But whilst bog-loving dragonflies have fewer places to live,
0:25:23 > 0:25:28other species find modern Britain more inviting than ever.
0:25:28 > 0:25:33Thousands of gravel pits, quarries and opencast mines
0:25:33 > 0:25:38have been flooded to create prime real estate for dragonfly larvae.
0:25:38 > 0:25:41And here, dragonflies such as the Emperor
0:25:41 > 0:25:44and Four-spotted Chaser are thriving.
0:25:47 > 0:25:51And global warming is actually helping, too.
0:25:54 > 0:25:55Since the 1980s,
0:25:55 > 0:25:59almost all of Britain's dragonflies have expanded northwards,
0:25:59 > 0:26:04and five new species have arrived from the warmer climates of Southern Europe.
0:26:06 > 0:26:10I'm pleased to say that dragonflies are continuing
0:26:10 > 0:26:14their 320-million-year reign on these islands.
0:26:23 > 0:26:27Imagine you were to wake up one morning and come face-to-face
0:26:27 > 0:26:31with the meanest, most terrifying animal in your world staring at you
0:26:31 > 0:26:33across the breakfast table.
0:26:33 > 0:26:35And you were its breakfast!
0:26:35 > 0:26:37Well, this is a fate that's been played out
0:26:37 > 0:26:39on rivers all over Britain
0:26:39 > 0:26:43to what could be described as our most put-upon mammal.
0:26:43 > 0:26:49A creature that's declined by 97% in the last 20 years.
0:26:49 > 0:26:50Now, I know what you're thinking.
0:26:50 > 0:26:54This now can't possibly be a romantic, happy tale
0:26:54 > 0:26:55from the riverbank.
0:26:55 > 0:27:00But, honestly, stay with us, because there IS a happy ending.
0:27:10 > 0:27:12The water vole.
0:27:12 > 0:27:15Surely our cutest British rodent.
0:27:15 > 0:27:21Many humans will know them as water rats, but they are definitely voles.
0:27:21 > 0:27:25All water voles need to set up home is a river to swim in,
0:27:25 > 0:27:29nice, soft banks to burrow in and plenty of grass and roots to eat.
0:27:29 > 0:27:32A water vole's home is its castle.
0:27:32 > 0:27:36They construct networks of tunnels and chambers
0:27:36 > 0:27:39extending up to five metres into a bankside,
0:27:39 > 0:27:41with specialised areas for storing food,
0:27:41 > 0:27:47sleeping and nesting, where they produce up to 40 offspring a year.
0:27:47 > 0:27:52There are two or more entrances, including one by the water,
0:27:52 > 0:27:54for emergency exits...
0:27:56 > 0:28:01..because a tasty water vole can never afford to let its guard drop.
0:28:03 > 0:28:06From the land, the stoat.
0:28:08 > 0:28:10The water vole runs for the tunnel
0:28:10 > 0:28:12but the stoat's flexible body can follow.
0:28:12 > 0:28:16The only escape is a quick dive into the water.
0:28:18 > 0:28:21From the water, the voracious pike.
0:28:24 > 0:28:27The quick-acting water vole scrambles to safety just in time.
0:28:29 > 0:28:32From the air, the barn owl.
0:28:34 > 0:28:39But once again, the water vole makes its swift escape.
0:28:40 > 0:28:42Now, the reason that water voles
0:28:42 > 0:28:45are so good at avoiding their predator compatriots
0:28:45 > 0:28:49is that they've been in Britain for a very long time.
0:28:56 > 0:28:59Around 10,000 years ago, after the ice sheets retreated,
0:28:59 > 0:29:02water voles from Southern Europe made the epic journey
0:29:02 > 0:29:06across an ancient land bridge, to colonise Britain.
0:29:06 > 0:29:08And these were water voles were black.
0:29:10 > 0:29:13Then, several thousand years later,
0:29:13 > 0:29:18they were pushed north by the BROWN water vole from the Balkans.
0:29:18 > 0:29:20Eventually a truce was reached,
0:29:20 > 0:29:22where the black voles hung on to Scotland
0:29:22 > 0:29:25and the brown invaders claimed England and Wales.
0:29:27 > 0:29:31At the start of the 20th century, there were over
0:29:31 > 0:29:35eight million water voles thriving in Britain's waterways.
0:29:35 > 0:29:40And in 1908, Ratty the water vole became a superstar.
0:29:43 > 0:29:46But sadly, fame didn't do the water voles any good.
0:29:49 > 0:29:52First there were two world wars.
0:29:53 > 0:29:58Humans, desperate for food, stripped bankside vegetation for crops
0:29:58 > 0:30:01and allowed cattle to trample water voles' homes.
0:30:03 > 0:30:04But worse was to come.
0:30:05 > 0:30:08A water vole apocalypse.
0:30:10 > 0:30:13So what's happening with the water voles?
0:30:13 > 0:30:16You know, when I was a kid, if I'd have wandered up the River Tale
0:30:16 > 0:30:20here in Devon, I'd have been listening for this sound...
0:30:21 > 0:30:25..the characteristic plop of a water vole diving beneath the surface
0:30:25 > 0:30:28and finding shelter in its burrow.
0:30:28 > 0:30:33But in 2002, water voles were declared extinct in the Southwest.
0:30:33 > 0:30:38That's the whole of Devon and Cornwall, two large counties.
0:30:38 > 0:30:41But how could an animal so prolific at procreating,
0:30:41 > 0:30:46so security-conscious, completely disappear? Here's a clue.
0:30:47 > 0:30:49You may be interested to know
0:30:49 > 0:30:52that it's been simply pouring into this country.
0:30:52 > 0:30:54Yes, mink coats.
0:30:54 > 0:30:59In the 1920s, the North American mink was imported into the UK
0:30:59 > 0:31:01to support the British fur trade,
0:31:01 > 0:31:07and by the 1970s there were no less than 800 mink ranches in Britain,
0:31:07 > 0:31:10some of them with as many as 5,000 animals,
0:31:10 > 0:31:13each one of them a hungry predator.
0:31:13 > 0:31:18And not only did some manage to escape, but in the '80s and '90s,
0:31:18 > 0:31:22thousands were released by animal rights activists.
0:31:22 > 0:31:26And ever since, the American mink has been on the rise
0:31:26 > 0:31:27in the wild in Britain.
0:31:28 > 0:31:30Fast and agile swimmers,
0:31:30 > 0:31:33they can attack water voles from water or land.
0:31:38 > 0:31:41And they won't stop until they've eaten them all.
0:31:47 > 0:31:52Since the 1950s, mink have eaten their way across Britain,
0:31:52 > 0:31:58and many black and brown water vole populations have been annihilated.
0:32:00 > 0:32:04But the mink kill other animals too, such as water fowl,
0:32:04 > 0:32:07and cause so much carnage that an army of humans
0:32:07 > 0:32:09has decided to take them on.
0:32:13 > 0:32:16Large chunks of Britain have been cordoned off,
0:32:16 > 0:32:18creating areas to be defended at all costs,
0:32:18 > 0:32:20where mink are trapped and killed.
0:32:22 > 0:32:26And the first of these was here in the Southwest.
0:32:30 > 0:32:34The surge has been so successful that the mink have been pushed back.
0:32:34 > 0:32:39So today's a great day because water voles are being re-introduced.
0:32:39 > 0:32:40How's it going, Mervyn?
0:32:40 > 0:32:42Yep, pretty good, thanks, Chris.
0:32:42 > 0:32:45I've done one hole, and we're just nearly finishing the other.
0:32:45 > 0:32:48So if you'd like to finish it off for us.
0:32:48 > 0:32:51OK. Perfect. I'll go and get some water voles.
0:32:51 > 0:32:54I've not done a lot of augering but I'll do my best.
0:32:54 > 0:32:58Pushing and turning at the same time. I think even I can manage that.
0:33:02 > 0:33:05The principle here is that we're digging starter burrows
0:33:05 > 0:33:08for these animals, somewhere to hide from predators
0:33:08 > 0:33:11whilst they settle down to their new life in the wild.
0:33:17 > 0:33:22Right. All we need now are the voles.
0:33:25 > 0:33:27Look at that. What a beauty.
0:33:27 > 0:33:30This is one of this year's young.
0:33:30 > 0:33:33It currently weighs just over 100 grams, which is
0:33:33 > 0:33:34a small vole, believe it or not.
0:33:34 > 0:33:37How are we going to get this animal into those burrows
0:33:37 > 0:33:40without risking losing it struggling across the ditch?
0:33:40 > 0:33:43It's the trusty crisp tube, Chris.
0:33:43 > 0:33:45The trusty crisp tube!
0:33:45 > 0:33:50Very Blue Peter, but I presume it works. Now, in you go.
0:33:50 > 0:33:53He's gone in there a treat. All right, let's put him in.
0:33:55 > 0:33:58Right, do you want to stick yours in, then, Mervyn?
0:33:59 > 0:34:01How many have you released here?
0:34:01 > 0:34:04Well, this year, about 140.
0:34:06 > 0:34:10I think he's gone in, Mervyn, straightaway.
0:34:11 > 0:34:14'As long as mink are kept at bay, water voles have a good chance
0:34:14 > 0:34:17'of reclaiming this piece of England.'
0:34:19 > 0:34:22If it works, in the future there'll be lots of little voles
0:34:22 > 0:34:25paddling up and down this pleasant English tributary.
0:34:27 > 0:34:30Let's hope that the brown water voles have been rescued
0:34:30 > 0:34:32in the nick of time.
0:34:36 > 0:34:40But to get a complete water vole's picture of Britain,
0:34:40 > 0:34:43we need to see how the black water voles of Scotland
0:34:43 > 0:34:44are coping with mink.
0:34:49 > 0:34:52This is Loch Muick on the Balmoral estate,
0:34:52 > 0:34:58where I've come to investigate a very peculiar triangle of murder.
0:34:58 > 0:35:02Researchers here on the Balmoral estate have established that where
0:35:02 > 0:35:07there are lots of rabbits - rabbits - there are no water voles.
0:35:07 > 0:35:10But where there aren't any rabbits, there are lots of voles.
0:35:10 > 0:35:12So, my nature detectives,
0:35:12 > 0:35:18this might imply that rabbits are eating the voles. The plot thickens.
0:35:19 > 0:35:23But rabbits aren't carnivores, so they can't be responsible.
0:35:23 > 0:35:26I suspect that somehow the mink is at the bottom
0:35:26 > 0:35:29of this rodent irregularity.
0:35:29 > 0:35:34What I need is a sort of Inspector Poirot for water voles.
0:35:34 > 0:35:37So I'm meeting one of Britain's leading experts
0:35:37 > 0:35:41who, perhaps reassuringly, also happens to be Belgian.
0:35:43 > 0:35:46'Xavier Lambin has been investigating
0:35:46 > 0:35:49'the black water voles of Balmoral for 12 years.'
0:35:49 > 0:35:51Let's check what we have. There she is.
0:35:51 > 0:35:53Oh, my goodness, look at that!
0:35:54 > 0:35:58What an animal, honestly! I've never seen a black water vole before.
0:35:58 > 0:36:03They're beautiful beasts. Lovely charcoal, brilliant black.
0:36:03 > 0:36:07I'm giving it points over the brown southern variety, I have to say.
0:36:07 > 0:36:10And what's the story between the water voles,
0:36:10 > 0:36:11the rabbits and the mink?
0:36:11 > 0:36:14Because clearly, the rabbits aren't eating the water voles.
0:36:14 > 0:36:16In the presence of American mink,
0:36:16 > 0:36:20we don't find water voles within 5km of a rabbit colony,
0:36:20 > 0:36:21a rabbit warren.
0:36:21 > 0:36:25Ah, so it IS the mink that are making the water voles disappear?
0:36:25 > 0:36:26Yes.
0:36:26 > 0:36:30It's quite difficult for a mink to make a living in the uplands,
0:36:30 > 0:36:32so when they have rabbits,
0:36:32 > 0:36:35they are able to spread further than what they would otherwise do.
0:36:35 > 0:36:37In doing so, that brings them closer
0:36:37 > 0:36:40to the surviving water vole colonies.
0:36:40 > 0:36:44So basically, the mink need the rabbits to sustain them in any area
0:36:44 > 0:36:47and whilst hunting those rabbits,
0:36:47 > 0:36:49they also snack on any voles they find?
0:36:49 > 0:36:51Yes.
0:36:51 > 0:36:52How did these voles survive,
0:36:52 > 0:36:55because presumably this area is pretty good for rabbits?
0:36:55 > 0:36:58Where did they go when the mink arrived?
0:36:58 > 0:36:59If you go up in the hills there,
0:36:59 > 0:37:02there are very extensive populations of water voles there.
0:37:02 > 0:37:05So the voles went right to the top of the mountains?
0:37:05 > 0:37:08As high as they could go. This was the refuge they could find,
0:37:08 > 0:37:11and we've managed to remove the mink
0:37:11 > 0:37:13from nearly 10,000 square kilometres
0:37:13 > 0:37:15and now we see the first sign of recovery.
0:37:15 > 0:37:19Voles are coming down from the hills and are reclaiming the ground,
0:37:19 > 0:37:22from which they were excluded previously by American mink.
0:37:22 > 0:37:24Look at that! What a top animal.
0:37:24 > 0:37:26We should let her go.
0:37:28 > 0:37:29Oh, what a beautiful animal!
0:37:29 > 0:37:31What an absolute stunner.
0:37:31 > 0:37:36Let's hope she's part of this whole recolonisation process.
0:37:42 > 0:37:48So, the British water vole story is one that reveals how one small
0:37:48 > 0:37:52change to our waterways can have devastating effects.
0:37:55 > 0:37:58Thankfully, now mink are being kept under control,
0:37:58 > 0:38:00from a water vole's perspective,
0:38:00 > 0:38:05Britain is once again starting to look like a great place to live.
0:38:20 > 0:38:23So far all of the animals we've been looking at spend most of
0:38:23 > 0:38:26their lives in or beside the water,
0:38:26 > 0:38:30but to truly get to grips with the state of Britain's waterways,
0:38:30 > 0:38:34what we need to do is consider a creature that spends all of its life
0:38:34 > 0:38:36beneath the surface of that water.
0:38:36 > 0:38:40I think I've got an ideal candidate. It's an effective predator,
0:38:40 > 0:38:43it's elusive prey and it tastes good on a plate.
0:38:53 > 0:38:56Yes, it's a fish, and not to be confused with the salmon.
0:38:56 > 0:38:59This is a trout.
0:38:59 > 0:39:02Just look at it - beautiful animal.
0:39:02 > 0:39:06Wonderful speckling across the top of its back and down its sides.
0:39:08 > 0:39:10So how did the trout
0:39:10 > 0:39:14come to be such an important resident of British waterways?
0:39:21 > 0:39:2410,000 years ago, as the ice melted,
0:39:24 > 0:39:28an inquisitive trout saw an opportunity, and it wasn't long
0:39:28 > 0:39:32before almost every river had a healthy population.
0:39:33 > 0:39:378,000 years later, and the Romans also took a liking
0:39:37 > 0:39:41to British waterways, building cities along the best trout rivers.
0:39:43 > 0:39:46They also brought fly-fishing.
0:39:48 > 0:39:521,400 years after that, the British Empire spread.
0:39:52 > 0:39:56Trout and the art of fly-fishing followed until trout from Britain
0:39:56 > 0:40:00swam in rivers across five continents.
0:40:02 > 0:40:05But with the industrialisation of Britain's waterways,
0:40:05 > 0:40:10trout disappeared from many of our once great rivers.
0:40:15 > 0:40:16But here is one river,
0:40:16 > 0:40:21away from the main industrialised areas, that has survived.
0:40:22 > 0:40:24The Itchen in Hampshire.
0:40:26 > 0:40:28One of the first to have been fished by the Romans
0:40:28 > 0:40:32and still one of the world's top trout habitats.
0:40:32 > 0:40:34So where better to come to understand
0:40:34 > 0:40:37what is a very unusual fish?
0:40:38 > 0:40:43Perhaps the weirdest thing about trout is that this species of fish
0:40:43 > 0:40:47can basically lay an egg which can develop into
0:40:47 > 0:40:51either one of two completely different types of animal.
0:40:51 > 0:40:56Just think about that. And which type is determined by the habitat.
0:40:56 > 0:41:00Now, here in the cool, clear waters of the Itchen, where there's masses
0:41:00 > 0:41:02of invertebrate life, good food for trout,
0:41:02 > 0:41:06paradoxically you find the smaller of the two.
0:41:06 > 0:41:09It's a thing called the wild brown trout.
0:41:11 > 0:41:15This is one of over a dozen similar streams in the South of England
0:41:15 > 0:41:19where there's enough food, such as caddis fly and mayflies,
0:41:19 > 0:41:23to sustain brown trout for all of their life cycle.
0:41:25 > 0:41:30And the reason it's so fertile is down to the geology.
0:41:30 > 0:41:34You see, the rock beneath the crystal-clear waters
0:41:34 > 0:41:37of the Itchen here is chalk, and it's very porous,
0:41:37 > 0:41:40so when it rains on the surrounding hills,
0:41:40 > 0:41:44all the water seeps through this into underground aquifers.
0:41:44 > 0:41:46And it's these that feed the sources
0:41:46 > 0:41:49of these type of chalk-stream rivers.
0:41:49 > 0:41:52And there's a benefit here, because the water
0:41:52 > 0:41:56is pretty much the same temperature throughout the course of the year.
0:41:56 > 0:42:02It doesn't vary seasonably or due to warm water running off the hills.
0:42:02 > 0:42:06And this means that it's a fantastic place for masses of
0:42:06 > 0:42:11aquatic plants and, living on these, masses of aquatic insects.
0:42:11 > 0:42:14And these in turn are great food for trout.
0:42:18 > 0:42:21But even here in brown-trout paradise,
0:42:21 > 0:42:24there's a problem on the horizon.
0:42:24 > 0:42:28You see, a third of Britain's human population lives in the Southeast
0:42:28 > 0:42:30and they all need water.
0:42:30 > 0:42:33Much of it comes from the same aquifers
0:42:33 > 0:42:36that feed the chalk streams.
0:42:36 > 0:42:40As a result, the chalk streams are drying up.
0:42:40 > 0:42:44And as anyone boiling a half-filled kettle will know,
0:42:44 > 0:42:50less water warms up faster, and no trout wants a warm stream.
0:42:50 > 0:42:52But if things get really bad,
0:42:52 > 0:42:55this species has a cunning survival strategy,
0:42:55 > 0:42:58because trout are capable of surviving
0:42:58 > 0:43:01in a very different environment from this.
0:43:05 > 0:43:08Just 25 miles south and look,
0:43:08 > 0:43:11this New Forest stream is a very different place.
0:43:11 > 0:43:14Conditions are different in the water too.
0:43:14 > 0:43:16You can see it's much murkier.
0:43:16 > 0:43:19There's a lot less aquatic vegetation in there, it's warmer,
0:43:19 > 0:43:22and critically, it's more acidic too.
0:43:22 > 0:43:25So it's home to a very different type of trout.
0:43:25 > 0:43:31They can be very hard to see in this murky water, but we're in luck.
0:43:31 > 0:43:34A shoal has just risen to the surface.
0:43:34 > 0:43:39These fish are typically twice as big as normal brown trout.
0:43:39 > 0:43:44So the question is, then, why and how do they get so big?
0:43:44 > 0:43:49Well, these things are sea trout, and the clue is in their name.
0:43:52 > 0:43:56Yes, all over Britain, there are rivers like this New Forest stream,
0:43:56 > 0:43:59which are poor in food.
0:43:59 > 0:44:04But giant trout still live here, and this is how.
0:44:04 > 0:44:09Leaving en masse, the young fish head downriver...
0:44:11 > 0:44:12..to become sea trout.
0:44:16 > 0:44:20And here they can gorge on the plentiful seafood
0:44:20 > 0:44:23before heading back to the river of their birth.
0:44:25 > 0:44:26So the question is,
0:44:26 > 0:44:30why on Earth do the sea trout bother to come back to it?
0:44:30 > 0:44:33Well, as with so many puzzling aspects of life,
0:44:33 > 0:44:36it comes down to...sex.
0:44:40 > 0:44:42They gather in the estuaries
0:44:42 > 0:44:45before making the epic journey back upriver to breed.
0:44:53 > 0:44:57They need a clean gravel bed where their eggs can be safely anchored
0:44:57 > 0:45:00under the cover of a bit of vegetation.
0:45:01 > 0:45:06Because of their large size, they can lay up to 38,000 eggs,
0:45:06 > 0:45:09so their time of feeding at sea has paid off.
0:45:12 > 0:45:16It strikes me as absolutely incredible
0:45:16 > 0:45:20that these two types of trout are, in fact, the same species.
0:45:20 > 0:45:22They can be genetically identical.
0:45:22 > 0:45:27It's sort of a case of brothers and sisters making lifestyle choices.
0:45:27 > 0:45:30One decides to be the stay-at-home brown trout,
0:45:30 > 0:45:33the other, the more adventurous sea trout.
0:45:38 > 0:45:42And these two strategies make British trout more resilient.
0:45:42 > 0:45:46Even though wild brown trout are declining in some chalk streams,
0:45:46 > 0:45:50elsewhere the sea trout are recolonising industrial rivers
0:45:50 > 0:45:52as they're cleaned up.
0:45:53 > 0:45:57Already they've returned to the Thames, the Taff and the Tyne.
0:46:01 > 0:46:04It's easy to forget, but each of the freshwater creatures
0:46:04 > 0:46:08that we've looked at so far does, in fact, exert a positive effect
0:46:08 > 0:46:09on the world it shares with humans.
0:46:09 > 0:46:13Think about the water voles. They naturally plough and fertilise
0:46:13 > 0:46:16the banks of the streams where they live.
0:46:16 > 0:46:20Then there are dragonflies. Their larvae are great food for fish.
0:46:20 > 0:46:25Fish like trout, which we like eating, and so do ospreys.
0:46:25 > 0:46:26And when ospreys eat them,
0:46:26 > 0:46:30they spread those nutrients into the wider environment.
0:46:30 > 0:46:33Now, I know what you're thinking. All this is terribly subtle
0:46:33 > 0:46:35and not at all obvious.
0:46:35 > 0:46:39But you know, there is one classic freshwater animal whose effects on
0:46:39 > 0:46:42the natural environment are far from subtle.
0:46:42 > 0:46:45In fact, they've always been hugely controversial.
0:46:56 > 0:46:58The beaver.
0:46:58 > 0:47:02An animal with the ability to build its own habitat,
0:47:02 > 0:47:04a bit like us humans.
0:47:06 > 0:47:09Its view of Britain is going to be especially fascinating because,
0:47:09 > 0:47:13having been extinct here for some 400 years,
0:47:13 > 0:47:16it's now on the verge of being reintroduced.
0:47:19 > 0:47:23So let's take a look at what makes a beaver a beaver.
0:47:26 > 0:47:28This one, Peter, is a babe, in both senses.
0:47:28 > 0:47:31It's a youngster, of course, and it's beautiful.
0:47:31 > 0:47:33It's about 14 weeks old, this fella,
0:47:33 > 0:47:36so he's still very much a youngster and that's why he's
0:47:36 > 0:47:38still chilled and happy to be held like he is.
0:47:38 > 0:47:41He's got all the beaver features already. He has.
0:47:41 > 0:47:44He's just a miniature version of the adult.
0:47:44 > 0:47:48Look at these back feet. I mean, look at that spread of webbing.
0:47:48 > 0:47:51He can swim fantastically fast, manoeuvre really well.
0:47:51 > 0:47:55Look at this tail. I mean, this is an amazing adaptation, isn't it?
0:47:55 > 0:47:58Mmm. It's a little bag of muscle in there
0:47:58 > 0:48:00and that is what gives them a huge thrust.
0:48:00 > 0:48:04What about their teeth? They're huge and incredibly tough, aren't they?
0:48:04 > 0:48:07That's the business end of a beaver. Their teeth does all their real work.
0:48:07 > 0:48:10They're fantastically adapted.
0:48:10 > 0:48:12They are like two sets of chisels,
0:48:12 > 0:48:16constantly self-sharpening to a razor edge. What about the coat, though?
0:48:16 > 0:48:18I mean, this is something else.
0:48:18 > 0:48:21These long guard hairs keep it waterproof, but beneath it
0:48:21 > 0:48:24there's this really thick downy layer,
0:48:24 > 0:48:26which is going to keep them warm, isn't it?
0:48:26 > 0:48:29This is the softest, most lovely fur you could ever feel.
0:48:29 > 0:48:33And that's unfortunately one of the reasons they went extinct.
0:48:38 > 0:48:42The extinction of beavers in Britain was the unhappy last chapter
0:48:42 > 0:48:45of a story which had started so well.
0:48:52 > 0:48:53Thousands of years ago,
0:48:53 > 0:48:57beavers may have paved the way for humans to settle Ice Age Britain,
0:48:57 > 0:49:01providing thick fur coats and energy-rich meat.
0:49:01 > 0:49:05But gradually, human demand for beaver parts escalated.
0:49:07 > 0:49:10Beaver teeth made excellent tools.
0:49:13 > 0:49:17And from Roman times, they were hunted both for castoreum -
0:49:17 > 0:49:20the anal secretion used to mark their territory -
0:49:20 > 0:49:22and for their testicles.
0:49:24 > 0:49:28It was believed that these had painkilling properties.
0:49:29 > 0:49:33And medieval humans were convinced that a desperate beaver would even
0:49:33 > 0:49:36bite off its own testicles, leaving them for the hunter,
0:49:36 > 0:49:39in return, saving its own life.
0:49:46 > 0:49:49But the thing that wiped out the beaver was its fur.
0:49:49 > 0:49:53One of the last ended up as a hat for Henry VIII.
0:49:55 > 0:50:00In the 1600s, the beaver finally went extinct in Britain.
0:50:02 > 0:50:05All that was left were a few archaeological remains
0:50:05 > 0:50:10and place names such as Beverley, which means Beaver Stream.
0:50:12 > 0:50:15So beavers disappeared 400 years ago.
0:50:15 > 0:50:19But does it really matter to anything other than a beaver?
0:50:19 > 0:50:21After all, we humans now have aspirin.
0:50:22 > 0:50:27Well, it could be that the beaver still has a lot to offer Britain.
0:50:29 > 0:50:32In recent times, some humans of the scientist variety have
0:50:32 > 0:50:35concluded that the way beavers modify the environment
0:50:35 > 0:50:38is good for many other species of wildlife.
0:50:38 > 0:50:42And to get an idea of what we might expect from a British beaver,
0:50:42 > 0:50:46here are some of its American cousins in action.
0:50:46 > 0:50:49The first thing the beavers want to do is to flood the area
0:50:49 > 0:50:51by building a dam.
0:50:53 > 0:50:58Each day, a beaver can shift ten times its own body weight.
0:50:58 > 0:51:00That's 200kg.
0:51:00 > 0:51:03As the dam grows, the water rises.
0:51:03 > 0:51:06But you know, they're not just dam builders.
0:51:06 > 0:51:10The beavers then excavate a whole network of channels
0:51:10 > 0:51:14leading to a supply of trees, whose bark and leaves they like to eat.
0:51:19 > 0:51:23Using their strong teeth, they can cut down up to 200 trees a year.
0:51:31 > 0:51:34They float them back to where they can build a lodge to live in,
0:51:34 > 0:51:38and raise a family safe from predators.
0:51:41 > 0:51:43The by-product of all this beaver land management
0:51:43 > 0:51:48is a fantastic new habitat for fish, insects and birds.
0:51:48 > 0:51:54So beavers hugely improve the health of the whole ecosystem.
0:51:56 > 0:51:58As a consequence of that, they've been reintroduced
0:51:58 > 0:52:00into many Western European countries.
0:52:00 > 0:52:04There are only a handful of exceptions - Albania and...
0:52:04 > 0:52:07Britain. Yes, Britain!
0:52:07 > 0:52:12Or, to be precise, Britain, with one tiny exception.
0:52:12 > 0:52:15An exciting but highly controversial trial
0:52:15 > 0:52:18tucked away in a remote part of Scotland.
0:52:21 > 0:52:24This is Knapdale in Argyll, Western Scotland.
0:52:24 > 0:52:29And it was here, in May of 2009, that beavers were translocated
0:52:29 > 0:52:32from Norway into an unfenced area of Scotland -
0:52:32 > 0:52:34that is, into the wild -
0:52:34 > 0:52:41for the first time in Britain in 400 years. So, why this part of Britain?
0:52:41 > 0:52:44Well, from a beaver's point of view, it's fantastic.
0:52:44 > 0:52:48Fertile lochs surrounded by acres of its favourite food -
0:52:48 > 0:52:51alder, rowan and willow trees.
0:52:51 > 0:52:53And from the human point of view,
0:52:53 > 0:52:57it's miles away from any large populations.
0:52:57 > 0:53:02And one thing's clear - the beavers are already rebuilding the place.
0:53:02 > 0:53:05This may look like a pile of brash
0:53:05 > 0:53:08you might find at the bottom of your grandfather's garden, but it isn't.
0:53:08 > 0:53:11It's the structural strength of this beaver dam.
0:53:11 > 0:53:15And all of this flooded woodland is brilliant for biodiversity.
0:53:15 > 0:53:19And look at this too. The beavers have toppled this over
0:53:19 > 0:53:22but already there's lots of natural regrowth, productivity.
0:53:22 > 0:53:26Deer are coming in and nibbling away and enjoying this.
0:53:26 > 0:53:28And when you think about it, we did this for years.
0:53:28 > 0:53:31This is just natural coppicing.
0:53:31 > 0:53:36And by coppicing, these beavers are creating more space, light
0:53:36 > 0:53:39and new growth in the surrounding woodland.
0:53:39 > 0:53:43But you can understand, I suppose, why some humans aren't keen.
0:53:43 > 0:53:48Imagine if this flooded woodland was in your backyard.
0:53:51 > 0:53:55Well, here in Scotland, tempers have flared.
0:53:55 > 0:53:59So I'm anxious to see how well these beavers are settling in
0:53:59 > 0:54:01to this corner of Britain.
0:54:05 > 0:54:09I've joined Roisin Campbell-Palmer of the Scottish Wildlife Trust.
0:54:09 > 0:54:12That's it. That's the lodge, isn't it?
0:54:12 > 0:54:15Yes, that's right. It's quite well camouflaged.
0:54:15 > 0:54:17It's very well camouflaged.
0:54:18 > 0:54:20We've waited until dusk.
0:54:20 > 0:54:23And we need to be extremely quiet.
0:54:24 > 0:54:26Wow. Look at that.
0:54:28 > 0:54:31If that one's feeling relaxed enough, it might even
0:54:31 > 0:54:33come out onto the bank and start feeding.
0:54:33 > 0:54:35That's fantastic.
0:54:35 > 0:54:37It's my first British beaver. Is it?
0:54:37 > 0:54:41My first British beaver. I'm so glad you've seen it.
0:54:41 > 0:54:43I never thought I'd see it. Really?
0:54:43 > 0:54:49Well, I've lived through years of delay, hesitancy, bickering.
0:54:49 > 0:54:52But now that it's happening, I can't tell you, I'm so excited.
0:54:57 > 0:54:58It's going over to the bank.
0:54:58 > 0:55:01If we're quiet, we might see it come out.
0:55:05 > 0:55:07(Just look at that.
0:55:07 > 0:55:09(It really doesn't come any better
0:55:09 > 0:55:12(when it comes to British wildlife watching.
0:55:13 > 0:55:16(You can hear and see this beaver who's just
0:55:16 > 0:55:22(25 metres in front of the canoe, gnawing on a piece of rowan tree.
0:55:28 > 0:55:32(I didn't come with any expectations of sitting so close
0:55:32 > 0:55:35(to one of these animals and being able to observe it like this.
0:55:35 > 0:55:38(In fact, here's another beaver. Another beaver's coming in.
0:55:41 > 0:55:43(Oh, they've joined up on the shore.
0:55:45 > 0:55:49(There seems to be a bit of bickering going on about the branch.
0:55:49 > 0:55:51(In fact...
0:55:52 > 0:55:55(..the beaver that's come in has stolen the branch.
0:55:55 > 0:55:59(It's dragging that piece of rowan across the top of the loch.
0:55:59 > 0:56:01(It's trailing out behind it.
0:56:03 > 0:56:04(Look at that!
0:56:06 > 0:56:09(To get so close to one of these reintroduced animals,
0:56:09 > 0:56:12(to be able to actually hear it gnawing away
0:56:12 > 0:56:15(and then see it on the surface.
0:56:15 > 0:56:19(Honestly, the project gets my thumbs up, big-time.)
0:56:22 > 0:56:25But maybe the strongest sign that the beavers are happy here
0:56:25 > 0:56:27is that they've already bred.
0:56:28 > 0:56:33This is a rare glimpse of one of Britain's first wild baby beavers,
0:56:33 > 0:56:35born in 2010.
0:56:36 > 0:56:41As long as they have a supply of water and trees, beavers can create
0:56:41 > 0:56:44their own habitat and live virtually anywhere.
0:56:44 > 0:56:47So for them, Britain is a land of opportunity, free from
0:56:47 > 0:56:52competition and predators, just waiting to be settled.
0:56:58 > 0:57:00But whether beavers make a comeback or not
0:57:00 > 0:57:04will depend on whether humans are prepared to share the UK
0:57:04 > 0:57:08with another species that likes to redesign the landscape.
0:57:12 > 0:57:16What really strikes me about our freshwater animals is
0:57:16 > 0:57:19that their lives are woven together with ours,
0:57:19 > 0:57:24through our mutual need for healthy freshwater habitats.
0:57:25 > 0:57:28It's not just that they are dependent on us.
0:57:28 > 0:57:30We need them too.
0:57:31 > 0:57:35But if they could speak, I wonder what they'd say to us?
0:57:35 > 0:57:39I wouldn't mind betting they'd say, "Keep the water pure and clean,"
0:57:39 > 0:57:44and, "No more introductions of dangerous non-native animals."
0:57:44 > 0:57:46But surely the main thing, the thing they'd be
0:57:46 > 0:57:52crying out for, begging for, is more good-quality freshwater habitats.
0:57:52 > 0:57:56Perhaps bigger, better wetland nature reserves.
0:57:56 > 0:57:59But then, hey, it's also down to me and you, and if we were to
0:57:59 > 0:58:04put anything, from a puddle to a pond in our back garden,
0:58:04 > 0:58:06I'm sure they'd appreciate that.
0:58:10 > 0:58:15Next time on The Animal's Guide To Britain, our grassland animals...
0:58:15 > 0:58:17Off you go!
0:58:17 > 0:58:20..their astonishing capabilities...
0:58:21 > 0:58:22Look at that.
0:58:22 > 0:58:25..and their surprising view of our landscape...
0:58:25 > 0:58:27What a fantastic thing.
0:58:27 > 0:58:30..in Britain's most dynamic habitat.
0:58:46 > 0:58:50Subtitles by Red Bee Media Ltd
0:58:50 > 0:58:54E-mail subtitling@bbc.co.uk
0:59:04 > 0:59:06If there is nothing new, then the Court of Appeal
0:59:06 > 0:59:09aren't going to change their decision.