0:00:05 > 0:00:08I'm on the cycle track
0:00:08 > 0:00:09that goes from Bodmin in Cornwall
0:00:09 > 0:00:11all the way up to Bristol.
0:00:11 > 0:00:14And it takes you through some glorious countryside.
0:00:16 > 0:00:19This bit here is particularly special.
0:00:21 > 0:00:23I always stop here
0:00:23 > 0:00:28because this seems like a perfect spot for otters.
0:00:28 > 0:00:30And, in fact, there are otters here -
0:00:30 > 0:00:32there's probably one watching us right now.
0:00:32 > 0:00:36But even though I've stopped here literally dozens of times,
0:00:36 > 0:00:39I've never seen one.
0:00:39 > 0:00:41But I'm not that surprised.
0:00:41 > 0:00:44Although otters are one of our largest carnivores,
0:00:44 > 0:00:47they're incredibly secretive and hard to see.
0:00:48 > 0:00:5340 years ago, otters very nearly became extinct in England,
0:00:53 > 0:00:56yet they seem to be making a remarkable recovery.
0:00:58 > 0:01:03But what we really know about them? Where are they? How can I see one?
0:01:03 > 0:01:07In the next hour, Springwatch's confirmed otterholics,
0:01:07 > 0:01:10Charlie Hamilton James and Simon King,
0:01:10 > 0:01:13will delve into the secret life of the otter.
0:01:13 > 0:01:18And Chris Packham will explore just what an otter's made of.
0:01:18 > 0:01:20And I'll be delving into the otter's past,
0:01:20 > 0:01:23looking forward into its future, and trying,
0:01:23 > 0:01:26with the help of some simple detective work,
0:01:26 > 0:01:30to see how you and I can actually see one for ourselves.
0:01:30 > 0:01:35So welcome to the Springwatch Guide To Otters.
0:02:04 > 0:02:09Meet the otter - one of our most charismatic animals.
0:02:09 > 0:02:11It's inquisitive, playful, elegant,
0:02:11 > 0:02:14but the otter has another side.
0:02:14 > 0:02:16It's a skilled hunter,
0:02:16 > 0:02:21fiercely territorial about guarding its patch. And what a patch!
0:02:23 > 0:02:26Otters live in some of the most gorgeous places
0:02:26 > 0:02:28in the British Isles.
0:02:30 > 0:02:34They recolonised these islands after the last ice age,
0:02:34 > 0:02:38and over 10,000 years, they've spread out from England rivers
0:02:38 > 0:02:40in the south, right up the coast
0:02:40 > 0:02:42to the northern most islands of Scotland.
0:02:46 > 0:02:49They're generally solitary, secretive creatures
0:02:49 > 0:02:51that like to keep themselves to themselves.
0:02:51 > 0:02:55You might just glimpse a swirl here, or a whiskery snout there,
0:02:55 > 0:02:57before it vanishes in the water,
0:02:57 > 0:02:59leaving nothing but a trail of bubbles.
0:03:04 > 0:03:07So what kind of animal is the otter?
0:03:07 > 0:03:10It's time to meet the family. Chris.
0:03:11 > 0:03:15Well, the otter is a member of the mustelid family of mammals.
0:03:15 > 0:03:17There are 54 species across the world,
0:03:17 > 0:03:21but we have seven in the UK, and here they are.
0:03:26 > 0:03:29You'll certainly be familiar with some of them.
0:03:29 > 0:03:32How about this little chap down here? This is the weasel.
0:03:33 > 0:03:38They're ferocious little carnivores, armed with really sharp canine teeth,
0:03:38 > 0:03:41and this one is especially designed
0:03:41 > 0:03:43to dive down into mouse and vole holes,
0:03:43 > 0:03:45where they predate those species.
0:03:45 > 0:03:47It's slightly larger relative, the stoat,
0:03:47 > 0:03:51does a very similar thing, except that it is after rabbits.
0:03:56 > 0:03:58Over here, we have the polecat.
0:03:58 > 0:04:00Now these are very closely related to
0:04:00 > 0:04:02the domestic ferrets that people keep.
0:04:02 > 0:04:06And then, the most arboreal of all of the British mustelids -
0:04:06 > 0:04:09the fabulous and exquisite pine marten.
0:04:09 > 0:04:12Once a species you could find all over the UK, but these days
0:04:12 > 0:04:16sadly restricted to Scotland, although they are spreading out.
0:04:16 > 0:04:19Perhaps the most familiar of all of them,
0:04:19 > 0:04:23though, is this animal - the badger. And here you can see that,
0:04:23 > 0:04:26typical of this group of animals, it has five non-retractable claws
0:04:26 > 0:04:31on its front foot, because it's using those to dig its set.
0:04:31 > 0:04:35That just leaves us with the two semi-aquatic species,
0:04:35 > 0:04:37the mink and the otter.
0:04:37 > 0:04:40Now, the mink here is not a native of the UK,
0:04:40 > 0:04:42it was introduced from North America.
0:04:42 > 0:04:44In fact, it's made a bit of a pest of itself.
0:04:44 > 0:04:47But the otter is truly a native,
0:04:47 > 0:04:50and when it comes to identification, well, look,
0:04:50 > 0:04:53the mink is significantly smaller, so I think that
0:04:53 > 0:04:56if you get a good view of an animal swimming through the water,
0:04:56 > 0:05:01you shouldn't mistake anything in the UK for the fabulous otter.
0:05:03 > 0:05:07And most of us, when we think about otters, you probably imagine them in
0:05:07 > 0:05:11a river, but they don't just live in rivers, they also live by the coast.
0:05:11 > 0:05:14Some people think that the otters that live in saltwater
0:05:14 > 0:05:16and the otters that live in fresh water
0:05:16 > 0:05:19are two completely different species,
0:05:19 > 0:05:22but they're not, they're the same species, the Eurasian otter.
0:05:22 > 0:05:26And of all the 13 different species of otter that live in the world,
0:05:26 > 0:05:29the Eurasian otter has the widest distribution,
0:05:29 > 0:05:31and if I had a map, I could show you.
0:05:31 > 0:05:35Oh, blow me down! Good Lord, I do have a map!
0:05:35 > 0:05:37So, look, you can see, in the pink,
0:05:37 > 0:05:40that's where the Eurasian otter is distributed.
0:05:40 > 0:05:43So the otters are here, here's the heartland in Europe,
0:05:43 > 0:05:48but they go down south to Morocco, and all the way across here,
0:05:48 > 0:05:52across the Himalayas, down to Indonesia in the south,
0:05:52 > 0:05:56and now up here to Kamchatka Peninsula in the north.
0:05:56 > 0:06:00But for our otters, although they're all the same species,
0:06:00 > 0:06:03they do have two very different lifestyles.
0:06:05 > 0:06:10On rivers in the south, otters are almost entirely active at night,
0:06:10 > 0:06:12while the coastal otters of the north,
0:06:12 > 0:06:17who rely on the shifting tides to hunt, are out and about by day.
0:06:21 > 0:06:24One of the best places to see otters in the UK
0:06:24 > 0:06:27are the Shetland Islands off the north coast of Scotland.
0:06:27 > 0:06:31Here, the sea has battered the coastline over millions of years
0:06:31 > 0:06:36to create 3,000 kilometres of perfect otter habitat -
0:06:36 > 0:06:39a rocky coastline full of shallow pools,
0:06:39 > 0:06:42with plenty of sea caves to rest up in.
0:06:43 > 0:06:47So this is the ideal place for Simon King
0:06:47 > 0:06:50to give us his first guide to otter watching.
0:06:57 > 0:07:00So, Simon, when you're out trying to spot otters,
0:07:00 > 0:07:02what's the first thing you look for?
0:07:02 > 0:07:03Seagulls, obviously!
0:07:03 > 0:07:05There's a black-back, great black-back,
0:07:05 > 0:07:09and herring gulls, all scavenging birds, looking for an easy meal.
0:07:09 > 0:07:11If you see any of those three species sitting on a rock,
0:07:11 > 0:07:13looking down into the rocks,
0:07:13 > 0:07:16it means it's watching an otter that's already feeding,
0:07:16 > 0:07:19and then you can very carefully move yourself around
0:07:19 > 0:07:21to get a view of the otter.
0:07:23 > 0:07:26SEAGULL CAWS
0:07:30 > 0:07:34Following them really closely is all down to field-craft.
0:07:36 > 0:07:39If I'm to stand a chance of a very close view,
0:07:39 > 0:07:40I've got to make my way down the beach,
0:07:40 > 0:07:46and the only way I can do that is to move when the otter is underwater.
0:07:49 > 0:07:50On the surface...
0:07:53 > 0:07:55..and down. OK.
0:07:55 > 0:08:00Otter dives rarely last much longer than 30 seconds,
0:08:00 > 0:08:02so I don't want to move...
0:08:02 > 0:08:04He's up.
0:08:06 > 0:08:09I won't move for much longer than 20 seconds.
0:08:11 > 0:08:13And down again.
0:08:14 > 0:08:19OK, I'm just going to tuck myself into the rocks.
0:08:21 > 0:08:22So it's absolutely vital that
0:08:22 > 0:08:27the wind is blowing from the otter towards me.
0:08:27 > 0:08:31That ensures that my scent doesn't reach the otter.
0:08:31 > 0:08:34OK, it's got a big fish. It's coming in towards me.
0:08:38 > 0:08:39Oh, that's beautiful!
0:08:43 > 0:08:45Just look at that.
0:08:47 > 0:08:48What a great view.
0:08:49 > 0:08:52No more than that.
0:08:57 > 0:09:02(I can't sit up.)
0:09:02 > 0:09:04(She's started to look in my direction.)
0:09:11 > 0:09:15To see an otter, like Simon, you've got to try and think like one.
0:09:17 > 0:09:20Whilst he was in Shetland, Simon got to know
0:09:20 > 0:09:24a couple of otter families, each living either side of a bay.
0:09:24 > 0:09:27There was Ebb, and her cub on one side,
0:09:27 > 0:09:30and Flow with two cubs on the other.
0:09:32 > 0:09:35Beautiful views. This is Flow, off to the right, that's the adult female.
0:09:35 > 0:09:38Her two cubs off to the left, 18 months old now.
0:09:38 > 0:09:40Pretty independent, those cubs,
0:09:40 > 0:09:43but they still depend on their mum for a certain amount of food,
0:09:43 > 0:09:46and, of course, an enormous amount of care and affection.
0:09:46 > 0:09:49They're a very, very close family unit, otters.
0:09:49 > 0:09:51Look at that, lovely serpentine grace,
0:09:51 > 0:09:53moving from land to sea as one,
0:09:53 > 0:09:57and otters that swim together, dive together.
0:09:57 > 0:10:00Look at this, one, two, three, all of them down, looking for food,
0:10:00 > 0:10:02we thought, but then within about a minute or two,
0:10:02 > 0:10:05the cubs were up on the surface having a complete barney.
0:10:05 > 0:10:09Now, this isn't a scrap, this is just hi-jinks, having a good time.
0:10:09 > 0:10:13But nothing being done with any serious aggression here.
0:10:13 > 0:10:16This is the sort of behaviour you might see when otters
0:10:16 > 0:10:19are courting, but right now this is just the youngsters playing together.
0:10:19 > 0:10:22And then, look at this, he loses his mate. "Where's he gone?
0:10:22 > 0:10:25"Where are you? Oh, there you are!"
0:10:25 > 0:10:28He thought the game was over, then it's all off again,
0:10:28 > 0:10:30they're just superb to watch.
0:10:30 > 0:10:33Absolutely magnificent.
0:10:33 > 0:10:35Oh, where is he gone? There you go.
0:10:35 > 0:10:39Quick bundle, and then no sooner did they disappear
0:10:39 > 0:10:42than one of them came up with a huge fish, a lumpsucker.
0:10:42 > 0:10:43They went back into feeding.
0:10:46 > 0:10:47And the game was over.
0:10:50 > 0:10:51Twice a day, these otter families
0:10:51 > 0:10:54have food delivered right to their door.
0:11:04 > 0:11:09A rising tide fills the shoreline with a seafood smorgasbord.
0:11:14 > 0:11:16Although their main diet is fish,
0:11:16 > 0:11:19in Scotland, otters are very partial to crabs.
0:11:23 > 0:11:24But whatever they are hunting,
0:11:24 > 0:11:27otters are spectacularly manoeuvrable underwater.
0:11:36 > 0:11:39How can an animal originally designed for life on the land
0:11:39 > 0:11:43be so good in water? Over to you, Chris.
0:11:48 > 0:11:52You've got to watch your fingers, but this is a fabulous place
0:11:52 > 0:11:54to appreciate just how well the otter
0:11:54 > 0:11:56is adapted to its aquatic environment.
0:11:56 > 0:11:59I'm at the British Wildlife Centre in Surrey,
0:11:59 > 0:12:01and these are obviously tame otters.
0:12:03 > 0:12:06They use their rear limbs, which are well webbed,
0:12:06 > 0:12:10to push that body through the water, and then they have that strong,
0:12:10 > 0:12:13stout tail, which they use as a rudder.
0:12:13 > 0:12:17The entire body is incredibly supple, it can twist and turn
0:12:17 > 0:12:20and bend, and when they're swimming as fast as they can,
0:12:20 > 0:12:24they undulate that body to improve their stroke, as it were.
0:12:26 > 0:12:29They want to be as streamlined as they possibly can,
0:12:29 > 0:12:32and, as you can see, they've achieved that
0:12:32 > 0:12:37with a long, lithe, slim body.
0:12:42 > 0:12:45Honestly, beautiful.
0:12:45 > 0:12:47You know, when I was a kid, I was obsessed with otters.
0:12:47 > 0:12:50I was so obsessed that my mother made a fake fur otter.
0:12:50 > 0:12:54It was a terrible representation of this beautiful animal,
0:12:54 > 0:12:58but I would wind it up at the foot of the bed and shine a torch on it
0:12:58 > 0:13:00and squint to make it look real.
0:13:00 > 0:13:03If this had happened to me when I was eight, I'd have burst.
0:13:03 > 0:13:06I'd have burst spontaneously.
0:13:07 > 0:13:11Aw, a childhood dream fulfilled.
0:13:11 > 0:13:14But come on, Chris, focus. Back to the engineering.
0:13:17 > 0:13:20To really understand how an animal works physically,
0:13:20 > 0:13:22we need to look inside it.
0:13:22 > 0:13:25We've got a fabulous opportunity to do that here,
0:13:25 > 0:13:28with this articulated otter skeleton.
0:13:28 > 0:13:31If we consider the vertebral column here,
0:13:31 > 0:13:37it's got all of these flanges, and those are muscle attachment points.
0:13:37 > 0:13:39Now, the bigger and broader they are,
0:13:39 > 0:13:42the larger the muscle is that's attached to them.
0:13:42 > 0:13:44So I can tell you, for instance,
0:13:44 > 0:13:46that there was a lot of muscle tissue there,
0:13:46 > 0:13:50and, therefore, this is a very supple and sinuous animal.
0:13:50 > 0:13:53And let's look at the feet, because, on land,
0:13:53 > 0:13:56this animal is walking on the soles of its feet, just like we do,
0:13:56 > 0:13:59and that tells me that it's not fast-moving,
0:13:59 > 0:14:03because, typically, animals which are fast-moving run on their toes.
0:14:03 > 0:14:06Think of cats and dogs, and horses, of course.
0:14:06 > 0:14:09But, of course, here, it doesn't need to be fast-moving on land,
0:14:09 > 0:14:12what it wants is broad feet, which are webbed, as you know,
0:14:12 > 0:14:17because these are used for pushing the animal through the water.
0:14:17 > 0:14:20So what we've got here is an animal that's supremely adapted
0:14:20 > 0:14:22for an aquatic lifestyle.
0:14:25 > 0:14:28There's no better way to see this than when,
0:14:28 > 0:14:31on a calm day in Shetland, Simon found an otter
0:14:31 > 0:14:34swimming in gin-clear water.
0:14:34 > 0:14:38It's really unusual to find a steep drop-off like this, with water
0:14:38 > 0:14:42directly beneath that's shallow enough to attract an otter to feed.
0:14:42 > 0:14:46And it's one thing to watch these animals on the surface, but look!
0:14:48 > 0:14:51I have to say, this really is the clearest view
0:14:51 > 0:14:53I have ever had of an otter hunting like this,
0:14:53 > 0:14:57and it's immediately clear that it's not chasing fish directly,
0:14:57 > 0:15:00or not at first, but instead... Ooh, there you go.
0:15:00 > 0:15:03..charging after fish that it disturbs from under rocks
0:15:03 > 0:15:05and through the seaweed.
0:15:05 > 0:15:09It spends most of its time foraging through that weed in the dense,
0:15:09 > 0:15:12dense bladderwrack and kelp.
0:15:14 > 0:15:17Little bit of a breather. Again, you never get to see their feet
0:15:17 > 0:15:19when they're on the water surface like this,
0:15:19 > 0:15:23but you can just see, she's so at home, perfectly relaxed.
0:15:23 > 0:15:24What a great view.
0:15:26 > 0:15:30Now, Simon King is clearly a confirmed otterholic.
0:15:30 > 0:15:34But there's one other cameraman who's always trying to get
0:15:34 > 0:15:36even closer than Simon.
0:15:36 > 0:15:39That is my good friend, Charlie Hamilton James.
0:15:41 > 0:15:45I saw my first otter when I was 16,
0:15:45 > 0:15:49and I'd gone to Shetland just to see otters.
0:15:54 > 0:15:56Luckily, I've had lots of cups of tea,
0:15:56 > 0:15:59so I'll be able to keep myself warm.
0:15:59 > 0:16:01I think that's too cold down there.
0:16:01 > 0:16:03The otters won't hang around long,
0:16:03 > 0:16:06so I need to get on with the serious business of being
0:16:06 > 0:16:10one of the only people ever to have swum with a truly wild otter.
0:16:15 > 0:16:18Usually they're incredibly wary.
0:16:18 > 0:16:21The slightest smell of a human and they're gone.
0:16:21 > 0:16:23But in the water, my scent is hidden,
0:16:23 > 0:16:26and whilst they know I'm here, they don't know what I am.
0:16:33 > 0:16:35I can see an otter working the shore,
0:16:35 > 0:16:37and I'm swimming gently towards it.
0:16:42 > 0:16:46And then suddenly, it appears.
0:16:46 > 0:16:48My first shot of an otter underwater.
0:16:49 > 0:16:52It's incredible how close I'm getting,
0:16:52 > 0:16:56and although inquisitive, it's still carrying on hunting and fishing.
0:17:09 > 0:17:10As it swims through the water,
0:17:10 > 0:17:14I can see for the first time how otters use their whole bodies
0:17:14 > 0:17:17to propel themselves along, not just their tails and feet.
0:17:20 > 0:17:23It's quite simply breathtaking to watch,
0:17:23 > 0:17:29and I feel it can't get any better. But it does.
0:17:34 > 0:17:38This bold and brazen dog otter is swimming up to investigate,
0:17:38 > 0:17:41coming so close he touches my camera.
0:17:41 > 0:17:44It really is a once-in-a-lifetime experience.
0:17:44 > 0:17:47GARBLES EXCITEDLY
0:17:57 > 0:18:00That is, without a doubt,
0:18:00 > 0:18:04the best wildlife encounter I have ever had in my life, by a mile.
0:18:04 > 0:18:05It is unbelievable.
0:18:07 > 0:18:11Now, like Charlie and Simon, I've spent some time in Shetland.
0:18:11 > 0:18:14DRAMATIC MUSIC
0:18:14 > 0:18:18And it's not always sunny and serene.
0:18:25 > 0:18:27The thing is, though,
0:18:27 > 0:18:30no self-respecting mother otter
0:18:30 > 0:18:34- is going to take her cubs out in that! - HE LAUGHS
0:18:34 > 0:18:37It takes a lot to stop an otter.
0:18:37 > 0:18:39This mother and her cub are out fishing.
0:18:39 > 0:18:43Even in gale force winds, they have to eat every day.
0:18:43 > 0:18:46If they don't, they'll starve.
0:18:46 > 0:18:49And surviving in these chilly North Sea waters
0:18:49 > 0:18:52requires some high-performance equipment.
0:18:53 > 0:18:58The otter's fur is short, fine, dense and velvety,
0:18:58 > 0:19:02and it's also extremely good at doing two essential things -
0:19:02 > 0:19:06keeping it dry and keeping it warm.
0:19:06 > 0:19:09Let's take a closer look at the fur using this microscope.
0:19:09 > 0:19:12I'll just focus it.
0:19:12 > 0:19:17You can see that the coarse hairs there are what we call
0:19:17 > 0:19:23the guard hairs. They're about 20 millimetres long, and they're covered
0:19:23 > 0:19:28with a water-repellent oil, and it's these that keep the otter dry.
0:19:28 > 0:19:30But if I part them
0:19:30 > 0:19:32and we delve underneath into the under-fur,
0:19:32 > 0:19:37these hairs are shorter, between 10 and 15 millimetres,
0:19:37 > 0:19:40and they occur at an incredible density -
0:19:40 > 0:19:4460,000 hairs per square centimetre
0:19:44 > 0:19:47all over this otter's body,
0:19:47 > 0:19:50and they are really good at keeping it warm,
0:19:50 > 0:19:53because they trap a layer of air here
0:19:53 > 0:19:57at a temperature ten degrees higher than the surrounding air or water.
0:19:57 > 0:20:01And when it comes to staying warm in water, you've got to try hard,
0:20:01 > 0:20:06because we lose temperature 27 times quicker through water
0:20:06 > 0:20:07than we do through air.
0:20:07 > 0:20:12Now, if you've got a coat like that, you certainly need to look after it.
0:20:12 > 0:20:16And one thing you'll notice is otters spend a lot of time grooming,
0:20:16 > 0:20:19particularly if they've been into saltwater,
0:20:19 > 0:20:23because the salt leads to the breakdown of that oil
0:20:23 > 0:20:25which is keeping the animal dry.
0:20:25 > 0:20:29So they'll come onto land, actively look for freshwater to bath in,
0:20:29 > 0:20:33and then spend a lot of time grooming, often in traditional spots.
0:20:33 > 0:20:37At the end of the day, if you've got a coat like this,
0:20:37 > 0:20:40you want to keep it in tiptop condition
0:20:40 > 0:20:42so you're nice and dry and warm.
0:20:42 > 0:20:46- HE SHIVERS - I could do with a bit of extra under-fur myself, it's bitter.
0:20:46 > 0:20:49Now, we've seen otters frolicking about
0:20:49 > 0:20:51in broad daylight on the coast.
0:20:51 > 0:20:55I don't know about you, but when I think about where an otter lives,
0:20:55 > 0:21:00I tend to think about something like this - a river, freshwater.
0:21:07 > 0:21:11In southern Britain, otters live not just on rivers,
0:21:11 > 0:21:15but in lakes and marshes too - anywhere, in fact,
0:21:15 > 0:21:19where there's water and plenty of bushes for cover.
0:21:19 > 0:21:22Here it's much harder to follow their lives,
0:21:22 > 0:21:25because on a river, otters come out at night.
0:21:28 > 0:21:31There's no twice-daily tide bringing food,
0:21:31 > 0:21:34but with dusk, the river comes alive.
0:21:36 > 0:21:40Away from prying eyes, fish like bullheads and eels emerge.
0:21:44 > 0:21:48And under the cover of darkness, otters come out to hunt them.
0:21:59 > 0:22:01As the otters emerge, so does Charlie,
0:22:01 > 0:22:04hoping to share their lives.
0:22:09 > 0:22:13He's spent more time than anyone filming their movements at night.
0:22:18 > 0:22:21Tonight he's using a thermal imaging camera,
0:22:21 > 0:22:24which works by detecting heat,
0:22:24 > 0:22:27and shows up any warm-blooded creature on the river.
0:22:28 > 0:22:33I've got the ducks on it. They're coming down the river,
0:22:33 > 0:22:38and the ducks... are right up against the edge.
0:22:41 > 0:22:44Ah, it's really hard to see it. There's the otter.
0:22:44 > 0:22:50I've got the otter, it's right near the ducks. They can't see it.
0:22:50 > 0:22:52I can only just see the ducks.
0:22:52 > 0:22:55Yeah, he's right next to the ducks.
0:22:55 > 0:22:58There goes the ducks. Oh...
0:22:58 > 0:23:01HE CHUCKLES
0:23:05 > 0:23:10There's something very special about seeing an otter at night like this.
0:23:10 > 0:23:13And I guess it's because you're seeing something
0:23:13 > 0:23:16that you shouldn't really be seeing.
0:23:22 > 0:23:25From all the hours he's spent watching them at night,
0:23:25 > 0:23:29Charlie's noticed the otters are constantly alert.
0:23:29 > 0:23:30They're hyper-sensitive
0:23:30 > 0:23:33to everything that's going on around them.
0:23:35 > 0:23:37OTTER SQUEAKS
0:23:40 > 0:23:45The family cruise the river like a well-oiled hunting machine,
0:23:45 > 0:23:47diving after fish,
0:23:47 > 0:23:51rooting around rocks to dislodge crabs and crayfish.
0:24:03 > 0:24:08Now and again they rest up in special places - their holts -
0:24:08 > 0:24:12hidden behind bushes or perhaps beneath a tangle of tree roots.
0:24:12 > 0:24:15This pattern of resting and hunting, resting and hunting,
0:24:15 > 0:24:19is how they pass the night.
0:24:23 > 0:24:26But I wonder if you, like me,
0:24:26 > 0:24:30have ever wondered how on earth otters find food
0:24:30 > 0:24:33in this murky, pitch-black water?
0:24:33 > 0:24:36One of the ways the otter is going to be finding its food
0:24:36 > 0:24:39is by using its whiskers -
0:24:39 > 0:24:43these highly modified hairs we call virissae.
0:24:43 > 0:24:46And they are extraordinarily sensitive.
0:24:46 > 0:24:48Well, not the hair itself - that's dead -
0:24:48 > 0:24:53but it's the tissue into which it's rooted that is absolutely packed
0:24:53 > 0:24:58full of neurons, nervous tissue, and this transmits the information
0:24:58 > 0:25:00to the animal's brain, and in otters,
0:25:00 > 0:25:03that part of the brain is significantly larger
0:25:03 > 0:25:08than in other species that are not so reliant on their whiskers.
0:25:08 > 0:25:11But, you know, it's not that the whiskers actually have to touch
0:25:11 > 0:25:15their prey, or anything they're looking for,
0:25:15 > 0:25:17because they are sufficiently sensitive
0:25:17 > 0:25:19to be able to detect the vortices.
0:25:19 > 0:25:22Now, that the churned up water that fish have left behind them
0:25:22 > 0:25:25when they're swimming through the river.
0:25:25 > 0:25:29And what's even more astonishing is that these animals
0:25:29 > 0:25:33can actually detect which species of fish has been swimming there,
0:25:33 > 0:25:36even when the fish is long gone.
0:25:36 > 0:25:38That's remarkable.
0:25:41 > 0:25:43That's an astonishing bit of biology,
0:25:43 > 0:25:45but when it comes to hunting,
0:25:45 > 0:25:49it seems that otters may have an even cleverer trick up their sleeve.
0:25:49 > 0:25:53Now, after hours and hours of patient observation,
0:25:53 > 0:25:56Charlie Hamilton James thinks he's discovered something
0:25:56 > 0:25:58completely unexpected.
0:26:01 > 0:26:03So, Charlie, I'm imagining I'm an otter,
0:26:03 > 0:26:07I'm swimming around at night, in possibly murky water,
0:26:07 > 0:26:09that's a tall order.
0:26:09 > 0:26:13Now, apart from using... sensing movement of fish,
0:26:13 > 0:26:16what other senses could I use to hunt?
0:26:16 > 0:26:20I've got this theory that otters also use smell underwater.
0:26:20 > 0:26:23Yeah, but they are mammals like us, so we have to go...
0:26:23 > 0:26:27- HE SNIFFS - ..and they're holding their breath.
0:26:27 > 0:26:29So how on earth can an otter smell underwater?
0:26:29 > 0:26:32Well, otters, they're supposed to have their nostrils
0:26:32 > 0:26:35completely closed underwater,
0:26:35 > 0:26:37but I used to feed the otter in my garden,
0:26:37 > 0:26:40because I was rehabilitating one to release him,
0:26:40 > 0:26:43and I used to put her fish in the river,
0:26:43 > 0:26:45so that the rats didn't get it.
0:26:46 > 0:26:49And she could find it. Wherever I put it, she could always find it.
0:26:49 > 0:26:52So I was always thinking, "How can she find it?"
0:26:52 > 0:26:55- It's not moving at all. - No, so the whiskers thing,
0:26:55 > 0:26:56that's not doing anything.
0:26:56 > 0:26:59It's dark, and the river's all murky, so she can't see it,
0:26:59 > 0:27:01so it's got to be something else going on.
0:27:01 > 0:27:05- OK.- So, I thought, "Well, I'd better try and film it."
0:27:05 > 0:27:08I invented some kit. It's an underwater camera.
0:27:08 > 0:27:11And I also put a nappy in it, because it leaked.
0:27:11 > 0:27:12THEY LAUGH
0:27:12 > 0:27:14And then I put it in the river,
0:27:14 > 0:27:17and I put a couple of infrared lights on it
0:27:17 > 0:27:20to light it up. So it's still pitch dark.
0:27:20 > 0:27:22I tied a dead fish to a brick,
0:27:22 > 0:27:24I stuck it in the murky river at night,
0:27:24 > 0:27:27and it found it straightaway.
0:27:27 > 0:27:29- How? Can we see it? - Yeah, have a look.
0:27:31 > 0:27:33- Here's the dead fish?- Yeah.
0:27:33 > 0:27:37And it's very quick, look, the otter comes in, picks it up, it's gone.
0:27:37 > 0:27:41Now, how does that tell us that it's smelling the fish?
0:27:41 > 0:27:45Right, well, at first, I didn't know anything else was going on,
0:27:45 > 0:27:46other than it had found it.
0:27:46 > 0:27:48So I had to go back, and look at this thing
0:27:48 > 0:27:51and look at this thing, and try and work out what was going on,
0:27:51 > 0:27:56and this is what I noticed. If you play it back really slowly...
0:27:56 > 0:27:57There. There's a little bubble.
0:27:57 > 0:28:01I thought that was just its nostril, but just that little flash there...?
0:28:01 > 0:28:03A little flash, it's putting a bubble out,
0:28:03 > 0:28:05and it's sniffing that bubble back in.
0:28:05 > 0:28:11And that's going to get loaded with scent and the chemicals of the fish.
0:28:11 > 0:28:15And then once it's worked out what it is, pick it up, swim off with it.
0:28:15 > 0:28:18It actually exudes a bubble of air,
0:28:18 > 0:28:22that somehow captures the scent, and it sucks it back into its nose.
0:28:22 > 0:28:25- Absolutely. - Did you just come up with that?
0:28:25 > 0:28:28Is that just the Charlie theory from nowhere?
0:28:28 > 0:28:31No, it's not. You know, I knew something was going on
0:28:31 > 0:28:34because I knew they could find them, and then I'd seen a BBC documentary,
0:28:34 > 0:28:38and in it they featured star-nosed moles -
0:28:38 > 0:28:42these very cool critters that hunt underwater.
0:28:42 > 0:28:45And what they'd done is they'd basically filmed them
0:28:45 > 0:28:48in very slow motion and proved that they are smelling
0:28:48 > 0:28:50by putting out bubbles and sniffing them back in again.
0:28:50 > 0:28:53- The scent is in the water?- Yeah.
0:28:53 > 0:28:56But I put cameras above the water.
0:28:56 > 0:28:58I wanted to look down on, to see exactly what was happening,
0:28:58 > 0:29:02so not just underwater. And you can see, she comes up the river,
0:29:02 > 0:29:04and she goes past the fish,
0:29:04 > 0:29:07and then she suddenly makes a very sharp turn, and grabs it.
0:29:07 > 0:29:10- So she clocked it. - Somehow she's detected it.
0:29:10 > 0:29:14And a bit like the wind, the river's going in one direction,
0:29:14 > 0:29:17so any scent's coming down the river, and when she went past it,
0:29:17 > 0:29:19she obviously clocked it, and came back round and grabbed it.
0:29:19 > 0:29:24So whatever it is, she clearly can do it. She is picking up that scent.
0:29:24 > 0:29:28And it looks like she's using the Charlie bubble scenting theory.
0:29:28 > 0:29:31I think that's probably what they'll call it from now on!
0:29:31 > 0:29:33Science in action, folks.
0:29:35 > 0:29:38Now we know otters are supreme swimmers,
0:29:38 > 0:29:43they have a highly sophisticated sense of both touch and smell,
0:29:43 > 0:29:48all of which combines to make them very, very good at catching fish.
0:29:48 > 0:29:51And that skill would inevitably bring them
0:29:51 > 0:29:54into conflict with humans.
0:29:54 > 0:29:59For hundreds of years, in Britain, otters have been hunted.
0:30:03 > 0:30:06Organised hunting of otters was going on
0:30:06 > 0:30:11way back in the 12th century, partially to control their numbers.
0:30:11 > 0:30:16But by the 20th century, otters were being hunted purely for sport.
0:30:18 > 0:30:21Someone who used to hunt them was James Williams,
0:30:21 > 0:30:24now one of the foremost otter experts in the country.
0:30:26 > 0:30:28What was the structure of the hunt?
0:30:28 > 0:30:31Well, I've got a picture here of my father,
0:30:31 > 0:30:33who was the master of the hunt.
0:30:33 > 0:30:36And there he is with some of the officials and the hounds...
0:30:36 > 0:30:40- Great photo.- ..and he organised where the hunt would go
0:30:40 > 0:30:44and then they would meet at 10 o'clock or 10.30
0:30:44 > 0:30:48at a bridge or a house and set off to try and find an otter
0:30:48 > 0:30:50and see if they could have a hunt.
0:30:50 > 0:30:55I've got to say, you've got the most wonderful collection of dogs in this, haven't you?
0:30:55 > 0:30:57- They're purebred otter hounds. - Oh, are they?
0:30:57 > 0:30:59- These are purebred otter hounds? - Yes, purebred otter hounds.
0:30:59 > 0:31:02Here's some more and you can see there
0:31:02 > 0:31:04what fine, upstanding animals they are.
0:31:04 > 0:31:07They're wonderful, wonderful hounds and I love them.
0:31:07 > 0:31:11- And everyone's on foot. Am I right? It's all...- Yes.
0:31:11 > 0:31:14- No horses or anything like that.- No, no horses. All on foot.- All on foot.
0:31:14 > 0:31:18And long poles which people sometimes say they were spears, they're not,
0:31:18 > 0:31:21they're just walking sticks because you've got to cross the river.
0:31:21 > 0:31:24Now, with a fox hunt, the fox will be in a bush or a...
0:31:24 > 0:31:28But an otter's going to be a much harder quarry, I would think,
0:31:28 > 0:31:29to find in the first place.
0:31:29 > 0:31:31Because there are far fewer of them,
0:31:31 > 0:31:35the first thing you have to do is find where the actual otter
0:31:35 > 0:31:39has gone in the night and follow its scent, which we call the drag,
0:31:39 > 0:31:41and hope that eventually you would locate the otter.
0:31:41 > 0:31:44How many separate otter hunts would there have been
0:31:44 > 0:31:47up and down the country?
0:31:47 > 0:31:50About two dozen. Most places were in the territory of an otter hunt.
0:31:50 > 0:31:54What sort of effect did the hunting back in those days
0:31:54 > 0:31:56have on otter numbers overall?
0:31:56 > 0:31:57Very little effect.
0:31:57 > 0:32:01We know that otter hunting was going in the reign of King John
0:32:01 > 0:32:04and otters survived perfectly well.
0:32:04 > 0:32:06I think the hunts were fairly beneficial
0:32:06 > 0:32:09in that they stopped people trapping, because it was much more fun
0:32:09 > 0:32:11to see if you could have a hunt and a day with your friends
0:32:11 > 0:32:14than to set a trap and go in the morning and find a mangled corpse,
0:32:14 > 0:32:19so I think the hunt, in fact, had a slightly protective effect.
0:32:22 > 0:32:27But for all that, between the 1950s and the 1970s,
0:32:27 > 0:32:31there was a sudden and dramatic decline in otters.
0:32:32 > 0:32:35The hunts were the first to notice there was a problem
0:32:35 > 0:32:38and they immediately sounded the alarm.
0:32:38 > 0:32:41But the numbers of otters continued to fall,
0:32:41 > 0:32:44and in 1978, otter hunting was made illegal.
0:32:47 > 0:32:51Something was devastating the population
0:32:51 > 0:32:54and, finally, after lengthy investigation,
0:32:54 > 0:32:56the cause was discovered.
0:33:00 > 0:33:03Toxic chemicals, introduced in the 1950s,
0:33:03 > 0:33:06were being used by farmers to kill pests
0:33:06 > 0:33:09and prevent fungal infestations.
0:33:09 > 0:33:11The poisons were washing into waterways
0:33:11 > 0:33:14and building up through the food chain.
0:33:17 > 0:33:20Otters are a top predator in our rivers
0:33:20 > 0:33:24so the toxins accumulated in their bodies to dangerous levels,
0:33:24 > 0:33:27causing blindness and fertility problems.
0:33:30 > 0:33:33By the early 1980s, otter numbers had crashed
0:33:33 > 0:33:36by up to 90% in England -
0:33:36 > 0:33:38they were on the brink of extinction.
0:33:40 > 0:33:44But a fictional tale about the life of an otter in North Devon,
0:33:44 > 0:33:47written at the peak of the hunting period,
0:33:47 > 0:33:50had begun to change people's attitudes.
0:33:50 > 0:33:54It was Henry Williamson's Tarka The Otter.
0:33:55 > 0:33:57Oh, this is Tarka when a child.
0:33:57 > 0:34:00"The eldest and biggest of the litter was a dog cub
0:34:00 > 0:34:04"and when he drew his first breath he was less than five inches long
0:34:04 > 0:34:08"from his nose to where his wee tail joined his backbone."
0:34:08 > 0:34:09That's a bit twee, isn't it?
0:34:09 > 0:34:12"His fur was soft and grey as the buds of the willow
0:34:12 > 0:34:14"before they opened Easter tide."
0:34:14 > 0:34:15That's all right.
0:34:15 > 0:34:19"He was called Tarka, which was a name given to otters..."
0:34:19 > 0:34:23"..many years ago by men dwelling in hut circles on the moor.
0:34:23 > 0:34:27"It means "little wanderer" or "wandering as water"."
0:34:28 > 0:34:30Now, I read Tarka as a child
0:34:30 > 0:34:36and it's a mixture of poetry and raw, almost brutal, reality.
0:34:36 > 0:34:38And Williamson was a realist.
0:34:38 > 0:34:41He even joined to his local otter hunt to make sure
0:34:41 > 0:34:45the book was as accurate as it possibly could be.
0:34:45 > 0:34:48But when he wrote Tarka The Otter 85 years ago,
0:34:48 > 0:34:50otters were still plentiful.
0:34:50 > 0:34:54The great crash in their numbers hadn't actually started.
0:34:54 > 0:34:58So this isn't really a book about otter conservation,
0:34:58 > 0:35:01but it did start to change the way that we think about otters.
0:35:01 > 0:35:05And that change continued with the publication of this book,
0:35:05 > 0:35:10Ring Of Bright Water by Gavin Maxwell, in 1960.
0:35:10 > 0:35:12And this book, and the film of the book,
0:35:12 > 0:35:15cemented a change that was already happening,
0:35:15 > 0:35:21turning the otter from vermin into a treasured part of British wildlife.
0:35:24 > 0:35:27Otters had had a make-over.
0:35:27 > 0:35:29Now they were playful and friendly
0:35:29 > 0:35:32and there was an outpouring of support for them.
0:35:33 > 0:35:36Otter conservation hit the political agenda
0:35:36 > 0:35:38and they finally became legally protected
0:35:38 > 0:35:41in England and Wales in 1978
0:35:41 > 0:35:43and just a few years later in Scotland.
0:35:49 > 0:35:52Where are you? Come on.
0:35:52 > 0:35:55Meanwhile, new conservation groups had sprung up
0:35:55 > 0:35:58and one of these was the Otter Trust,
0:35:58 > 0:36:02set up in 1972 by Philip and Jeanne Wayre.
0:36:03 > 0:36:07They were so passionate about otters they bought a farm in Suffolk
0:36:07 > 0:36:10and created large breeding enclosures by a lake.
0:36:12 > 0:36:15Rescued otters were taken in and bred in captivity
0:36:15 > 0:36:19and in 1983 the first three otters - two females and a male -
0:36:19 > 0:36:21were released into a river in Suffolk,
0:36:21 > 0:36:24where it was hoped they would start a wild population.
0:36:28 > 0:36:31So the otters took a massive hit,
0:36:31 > 0:36:34but then the chemical pollutants were banned.
0:36:34 > 0:36:36The otters got legal protection
0:36:36 > 0:36:39and a lucky few even got a helping hand directly.
0:36:41 > 0:36:45We had paved the way for their recovery - now it was up to them.
0:36:49 > 0:36:51Good news for the otter's recovery
0:36:51 > 0:36:53is that it can breed at any time of year
0:36:53 > 0:36:56and produce a litter of two or occasionally three cubs.
0:36:59 > 0:37:01The den might be an old rabbit burrow
0:37:01 > 0:37:04or a hole in a tangle of tree roots.
0:37:04 > 0:37:06It just needs to be snug and secluded.
0:37:08 > 0:37:10OTTERS SQUEAK
0:37:10 > 0:37:12The cubs grow quite fast,
0:37:12 > 0:37:16playing and sparring with each other to build up their strength.
0:37:22 > 0:37:24It's not until they're about four months old
0:37:24 > 0:37:27that they first venture, tentatively, out into the water.
0:37:29 > 0:37:33The family call to each other with piercing whistles
0:37:33 > 0:37:35to stick close together in the dark.
0:37:39 > 0:37:41OTTERS WHISTLE
0:37:41 > 0:37:44Mum teaches them how to hunt underwater
0:37:44 > 0:37:46and over the next eight months
0:37:46 > 0:37:51they'll learn all the skills they need to become fully independent.
0:37:55 > 0:37:58So if you ever see a group of otters together like this,
0:37:58 > 0:38:01it's invariably a mother and her cubs -
0:38:01 > 0:38:04the male dog otter doesn't stick around.
0:38:07 > 0:38:12Whether on a river or by the coast, dog otters are loners.
0:38:12 > 0:38:16As soon as they're fully grown they move away from home
0:38:16 > 0:38:18to find territories of their own.
0:38:18 > 0:38:22And this they guard aggressively against anyone.
0:38:27 > 0:38:30One of the ways they define their territory
0:38:30 > 0:38:32is by marking its boundaries with scent.
0:38:34 > 0:38:39Otter spraint - their poo - is a language all of its own.
0:38:39 > 0:38:42Left on rocks or sandy mounds, it's a warning to keep out,
0:38:42 > 0:38:46a message that Simon has clearly failed to heed.
0:38:46 > 0:38:49And here it is, on all of the little high points.
0:38:49 > 0:38:53This rock, a great mass of spraint here, here.
0:38:53 > 0:38:54Behind me, here.
0:38:54 > 0:38:56And if you get a close look
0:38:56 > 0:39:00and there are still the odd bubble on, then just keep still
0:39:00 > 0:39:03cos the chances are the otter's only just been here
0:39:03 > 0:39:05and it's somewhere nearby.
0:39:08 > 0:39:12Spraint is actually a complex method of communication,
0:39:12 > 0:39:15and just how complex has only recently become clear.
0:39:20 > 0:39:22Oh, yeah. Look at that.
0:39:22 > 0:39:26You can clearly see the reflective qualities there
0:39:26 > 0:39:29of a lot of fish scales.
0:39:29 > 0:39:31But, of course, to the otters,
0:39:31 > 0:39:35this material has another very clear function
0:39:35 > 0:39:39and it's all about communicating through smell
0:39:39 > 0:39:43and I've got some fresher samples that have been collected here
0:39:43 > 0:39:47that haven't dried out and I'm going to give them a bit of a sniff test.
0:39:47 > 0:39:51Now, some people say that it smells like freshly mown hay,
0:39:51 > 0:39:55some, jasmine tea, but to me,
0:39:55 > 0:39:58that's just pure otter.
0:39:58 > 0:40:03The smell is made up of 100 different components,
0:40:03 > 0:40:06but 17 of those are used by the otters
0:40:06 > 0:40:09to identify the spraint to an individual level.
0:40:09 > 0:40:12So if an otter was to sniff this itself
0:40:12 > 0:40:15it could tell you whether that was male or female,
0:40:15 > 0:40:18five, six, seven, eight years old,
0:40:18 > 0:40:22whether it was sexually mature, whether it was sexually active.
0:40:22 > 0:40:26It's Brian and he's had a fish masala, without any doubt.
0:40:26 > 0:40:30Now we can take DNA from this spraint
0:40:30 > 0:40:34and identify the otters down to individual level.
0:40:34 > 0:40:39So, you see, far from being a nuisance and something a bit quirky,
0:40:39 > 0:40:42otter spraint is incredibly useful both to man and beast.
0:40:45 > 0:40:50Over the past few decades, signs such as spraint and paw prints
0:40:50 > 0:40:54have been used to try to chart the otter's comeback in England,
0:40:54 > 0:40:58and although overall this shows encouraging signs of recovery,
0:40:58 > 0:41:03it's difficult to know exactly how many otters there are now in the UK.
0:41:04 > 0:41:08Trying to identify individual otters using their tracks
0:41:08 > 0:41:12and their spraint is notoriously difficult, but in the future
0:41:12 > 0:41:16this new DNA technique should make it much, much easier
0:41:16 > 0:41:21and help us build a more reliable picture of overall otter numbers.
0:41:24 > 0:41:28Research so far suggests otters are steadily recovering,
0:41:28 > 0:41:32with numbers estimated at somewhere around 2,000 in England
0:41:32 > 0:41:35and perhaps 8,000 in Scotland and Wales.
0:41:45 > 0:41:49In Scotland, where hunting's now been banned for 30 years,
0:41:49 > 0:41:53Simon recently found signs that otters are getting bolder.
0:41:55 > 0:41:59This is an otter trap, or, as they are known locally,
0:41:59 > 0:42:04an otter "hoose", built to trap otters for their fur.
0:42:06 > 0:42:10This would have been the area that the otter was attracted to going in
0:42:10 > 0:42:16and here there would have been a wooden sliding trapdoor
0:42:16 > 0:42:19connected to a string that went inside the structure
0:42:19 > 0:42:23to a pressure pad and if the otter walked inside,
0:42:23 > 0:42:27touched the rock, the door would close behind it.
0:42:27 > 0:42:30And then when the otter hunter came by on his rounds
0:42:30 > 0:42:34he'd lift one of the big rocks at the top, kill the otter, take it out.
0:42:34 > 0:42:37Now, of course, otters are fully protected
0:42:37 > 0:42:42and what is so fantastic and ironic is that this otter trap at least
0:42:42 > 0:42:46is being used very, very regularly by the local otter, or otters,
0:42:46 > 0:42:49as a resting place, and their sign is everywhere.
0:42:51 > 0:42:55There's a spraint here which is no more than an hour old
0:42:55 > 0:42:59and I can see where the animal has collected bedding
0:42:59 > 0:43:04and made a lovely, warm, cosy nest just inside.
0:43:04 > 0:43:07How strange that a structure designed to kill otters
0:43:07 > 0:43:09should prove to be a des-res.
0:43:13 > 0:43:16As they slowly spread across the UK,
0:43:16 > 0:43:19otters are finding new friends to help them on their way.
0:43:20 > 0:43:22On a rain-soaked day last year
0:43:22 > 0:43:27I went to help some volunteers, led by inventor Chris Matcher,
0:43:27 > 0:43:29making specially constructed otter holts.
0:43:34 > 0:43:37'I've put up plenty of bird boxes but an otter prefab?
0:43:39 > 0:43:42'Like any flatpack, well, you know how it goes.'
0:43:42 > 0:43:46- D?- D. Where's D? - Which way round does it go?
0:43:46 > 0:43:49- It should be the other way around. - That should be that way round.
0:43:49 > 0:43:52B. That's B.
0:43:52 > 0:43:53(It never goes smoothly.)
0:43:53 > 0:43:55'But, seriously, when you're not filming,
0:43:55 > 0:43:58'this holt can be put together in under an hour.'
0:43:59 > 0:44:02Girls with power drills - very exciting!
0:44:07 > 0:44:11Done. Chris, thank you for a marvellous day out.
0:44:11 > 0:44:13- Look what we've created. - Thank you very much.
0:44:13 > 0:44:16I shall volunteer for more of this sort of work(!)
0:44:18 > 0:44:21Let's get out of this!
0:44:23 > 0:44:27Excellent! And helping otters isn't just about building nest boxes -
0:44:27 > 0:44:30sometimes it means playing surrogate mum.
0:44:33 > 0:44:37When these three orphaned cubs were found by a roadside,
0:44:37 > 0:44:40a local wildlife sanctuary took them in.
0:44:40 > 0:44:42The cubs had never been in water
0:44:42 > 0:44:45so when the time was right, a swimming lesson was arranged.
0:44:49 > 0:44:51Over the next 18 months,
0:44:51 > 0:44:54the cubs were taught to hunt and fend for themselves
0:44:54 > 0:44:57and eventually they were put back into the river
0:44:57 > 0:44:59very close to where they were found.
0:45:06 > 0:45:09The one thing that has helped the otter's recovery
0:45:09 > 0:45:12more than anything else is the clean-up of our rivers.
0:45:14 > 0:45:16And although pollution is still a problem,
0:45:16 > 0:45:19many rivers have improved dramatically.
0:45:21 > 0:45:25Otters are a litmus, a test, for the health of a river
0:45:25 > 0:45:29and their presence shows that now many of our rivers
0:45:29 > 0:45:32are the healthiest they've been for 20 years.
0:45:35 > 0:45:37And that's good news,
0:45:37 > 0:45:40not only for otters, but for all our river life.
0:45:46 > 0:45:49It's not just our cameras catching glimpses of otters -
0:45:49 > 0:45:53here are some of your photos from around the country,
0:45:53 > 0:45:56courtesy of our Flickr photo group.
0:46:00 > 0:46:03No longer restricted to coast and countryside,
0:46:03 > 0:46:06some 21st-century otters are living right among us.
0:46:09 > 0:46:11In the cathedral city of Winchester,
0:46:11 > 0:46:15CCTV captured these remarkable images.
0:46:18 > 0:46:21A mother and no fewer than three cubs
0:46:21 > 0:46:24playing quite happily directly underneath the city's mill.
0:46:26 > 0:46:29The Wildlife Trust now estimate that otters are established
0:46:29 > 0:46:32in at least 13 urban centres.
0:46:32 > 0:46:35In Manchester, evidence of otter activity
0:46:35 > 0:46:38was recorded for the first time since the early 1900s.
0:46:40 > 0:46:44And in Newcastle, Simon was thrilled by the sight of an otter
0:46:44 > 0:46:46in the heart of the city.
0:46:49 > 0:46:54That's the trail of bubbles that every otter watcher wants to see.
0:46:54 > 0:46:56I find it truly wonderful
0:46:56 > 0:47:01to think that as we drive over these bridges in city centres,
0:47:01 > 0:47:05scenes like these might well be playing out
0:47:05 > 0:47:08under our wheels all over the country.
0:47:11 > 0:47:16And this is testament to an enormous turnaround
0:47:16 > 0:47:18in the way we treat our waterways.
0:47:18 > 0:47:22The fact that otters and herons can find sufficient food
0:47:22 > 0:47:28in these urban rivers and pools is a clear sign
0:47:28 > 0:47:32that these freshwaters live up to their name - just that, fresh...
0:47:34 > 0:47:36..and life-giving.
0:47:38 > 0:47:42Now, otters are naturally long-distance travellers
0:47:42 > 0:47:45and that's what's bringing them into our cities.
0:47:45 > 0:47:49But not everyone is quite so pleased to see them in the suburbs.
0:47:49 > 0:47:52Some garden ponds have been receiving
0:47:52 > 0:47:54some very unwelcome visitors.
0:47:58 > 0:48:04Imagine a small pond with a big, sluggish koi carp in it.
0:48:04 > 0:48:08To an opportunist like an otter, it's irresistible.
0:48:20 > 0:48:23It's not just ornamental fish ponds that are getting hit.
0:48:23 > 0:48:25Up and down the country,
0:48:25 > 0:48:29otters are becoming a real headache for commercial fisheries too
0:48:29 > 0:48:32and I'm off to Somerset to find out exactly what's going on.
0:48:38 > 0:48:41This lake is owned by an angling club in Bridgwater
0:48:41 > 0:48:44and today its vice president, Danny Danahy,
0:48:44 > 0:48:47is having to restock it with carp.
0:48:48 > 0:48:50Now, Danny,
0:48:50 > 0:48:55I can't help noticing the whole of the lake is like Colditz.
0:48:55 > 0:48:58You've had to go to some really extreme lengths to protect this.
0:48:58 > 0:49:00- Yes.- What has happened?
0:49:00 > 0:49:07- Over the last four years, we've put in approximately 4,000 fish.- Right.
0:49:07 > 0:49:10Last Thursday, we had about 50.
0:49:10 > 0:49:13Mainly roach, small bream.
0:49:13 > 0:49:18The 1,500 carp we put in more or less gone.
0:49:18 > 0:49:21That must have been crushingly disappointing for you.
0:49:21 > 0:49:25Terribly. Terribly. It's costing us an awful lot of money.
0:49:25 > 0:49:28The fence, we've put the fence up to try and stop
0:49:28 > 0:49:31what we believe is the otter doing it.
0:49:33 > 0:49:36'There are a variety of different animals it might be,
0:49:36 > 0:49:38'not just otters.
0:49:38 > 0:49:40'Mink will go for roach and bream,
0:49:40 > 0:49:43'and with a slump in fish stocks out at sea,
0:49:43 > 0:49:46'more and more cormorants are coming inland to hunt.'
0:49:46 > 0:49:51What's led you to think that it is the otter in general?
0:49:51 > 0:49:54Fishermen are actually seeing them on the big lake over there.
0:49:54 > 0:49:59We've also found paw prints, spats, dead fish.
0:49:59 > 0:50:02- Dead fish, yeah.- Dead fish.
0:50:02 > 0:50:05From the photos of fish carcasses taken by the club,
0:50:05 > 0:50:07it does look like otter.
0:50:07 > 0:50:10They'll go for carp because they're slow and easy to catch
0:50:10 > 0:50:14and they typically pick out the muscle just behind the gills,
0:50:14 > 0:50:16leaving the rest of the fish untouched.
0:50:18 > 0:50:20We believe that they're coming from the river,
0:50:20 > 0:50:22- which is in that direction.- Ah.- OK?
0:50:22 > 0:50:25And we believe that they're using that as a superhighway
0:50:25 > 0:50:27to come off onto lakes like ours.
0:50:27 > 0:50:30And they're opportunistically looking for feeding stations
0:50:30 > 0:50:32and they've found your fisheries here.
0:50:32 > 0:50:34Found our fishery and helped themselves.
0:50:35 > 0:50:39As otters are legally protected, Danny's had to invest
0:50:39 > 0:50:42in putting up some sort of barrier to keep them out.
0:50:43 > 0:50:45And you had to sink that into the ground?
0:50:45 > 0:50:48That's gone into the ground, about 18 inches into the ground.
0:50:48 > 0:50:52- It's not a cheap option. - No, no. Very, very expensive.
0:50:52 > 0:50:56For a lot of people, it could be the difference between being in business
0:50:56 > 0:50:58- or going out of business, you know? - Yeah.
0:50:58 > 0:51:01And stock is the most important thing.
0:51:04 > 0:51:06Hmm, that's tricky.
0:51:06 > 0:51:08And the growth in commercial fisheries and fish farms
0:51:08 > 0:51:11happened when there were hardly any otters around.
0:51:11 > 0:51:14And now the otters are making a comeback...
0:51:14 > 0:51:16Well, for an otter, this must be like finding
0:51:16 > 0:51:19a free all-you-can-eat buffet.
0:51:19 > 0:51:23I suppose the only option is to think very seriously about fencing.
0:51:26 > 0:51:29All these sightings of otters could give the impression
0:51:29 > 0:51:32that their comeback is complete,
0:51:32 > 0:51:35but, in fact, whilst it looks like they've recovered their range,
0:51:35 > 0:51:38they definitely haven't recovered their numbers.
0:51:41 > 0:51:44But they ARE coming back.
0:51:44 > 0:51:46And that means we've all got a better chance
0:51:46 > 0:51:48of seeing one for ourselves.
0:51:49 > 0:51:53So how do we go about it? Well, I know just the man.
0:51:54 > 0:51:57OK, Charlie, I've got maybe ten minutes.
0:51:57 > 0:52:00I am desperate to see an otter. How do I see one?
0:52:00 > 0:52:03Well, you're probably not going to see one, to be honest,
0:52:03 > 0:52:07but there's a whole selection of signs that you can look for
0:52:07 > 0:52:09to tell you if there is an otter there, at least.
0:52:09 > 0:52:12So we have to turn otter detective.
0:52:17 > 0:52:19I know the basics of what we're after -
0:52:19 > 0:52:21paw prints, holts in the banks
0:52:21 > 0:52:25and the heady smell of jasmine tea from their spraint -
0:52:25 > 0:52:30but I'm hoping Charlie can fill me in with some fieldcraft tips.
0:52:30 > 0:52:32I've got the right man - he's scaring me to death
0:52:32 > 0:52:36with gruesome tales of their leftovers.
0:52:36 > 0:52:40If an otter eats a trout, it'll hold it like that on the body
0:52:40 > 0:52:42and start with the head.
0:52:42 > 0:52:45You know what I mean? Till it's gone.
0:52:45 > 0:52:48You'll find the crayfish, it'll be the head and the claws they'll leave.
0:52:48 > 0:52:52If you find the back of a crab, often they'll have a single hole in it.
0:52:52 > 0:52:55You know, the canine of the otter has gone through it.
0:52:55 > 0:52:57Rat tails, so they've eaten the whole of the rest of the rat
0:52:57 > 0:52:59and they've just left the tail.
0:52:59 > 0:53:04'OK, Charlie, enough. Show me some hard evidence now!'
0:53:04 > 0:53:06What's the very first thing in your top ten otter signs?
0:53:06 > 0:53:09- What are we looking for? - This, basically, look.
0:53:09 > 0:53:10All these little dotty things?
0:53:10 > 0:53:12Look, there you go. All the way, straightaway.
0:53:12 > 0:53:15Any nice wet bit of mud along the edge of the river,
0:53:15 > 0:53:18if it's got otters, it's generally going to have footprints.
0:53:18 > 0:53:20That could be a dog to the untutored eye.
0:53:20 > 0:53:22What are we looking for that makes it otter?
0:53:22 > 0:53:24Well, key thing is, it's got five toes, an otter,
0:53:24 > 0:53:28and dogs and foxes have got four. But they're so distinctive.
0:53:28 > 0:53:31Look, you can see these teardrop paw marks,
0:53:31 > 0:53:33like upside-down teardrops, straightaway.
0:53:33 > 0:53:35They are sharp at the end, like that.
0:53:35 > 0:53:38What sort of size?
0:53:38 > 0:53:40- Look at that! - All right, let's measure one.
0:53:40 > 0:53:42I always have a little measurer.
0:53:42 > 0:53:44You're looking at about five centimetres.
0:53:44 > 0:53:48- I would have said that's sub adult, teenager, maybe.- Teenage otter?
0:53:48 > 0:53:51- Early teens.- Early teens otter?- Yeah, you know that it'll have Mum with it.
0:53:51 > 0:53:54So if there's a mum and a cub,
0:53:54 > 0:53:57at somewhere on this river will be a dog otter,
0:53:57 > 0:53:59cos he'll have a huge territory,
0:53:59 > 0:54:02encompassing several different females.
0:54:02 > 0:54:04So you know just from seeing these small prints
0:54:04 > 0:54:06there are probably three otters here,
0:54:06 > 0:54:08- even though we are only seeing the prints of one.- Amazing.
0:54:15 > 0:54:17Now, Charlie, this is interesting.
0:54:17 > 0:54:22It looks like a sort of a trail here going up there. Could that be otter?
0:54:22 > 0:54:24Absolutely. Otters cut corners all the time,
0:54:24 > 0:54:26and they cut corners when they are going upriver.
0:54:26 > 0:54:28They don't need to cut corners when going down river
0:54:28 > 0:54:30because they've got the energy of the river
0:54:30 > 0:54:33so they're not expending any energy, but when they're coming upriver,
0:54:33 > 0:54:36it's much easier to get out and cut a corner off.
0:54:36 > 0:54:39Now, obviously, otters are fishing a lot of the time,
0:54:39 > 0:54:41but sometimes they're not, they're just on a mission.
0:54:41 > 0:54:42And you're trying to film them,
0:54:42 > 0:54:44trying to keep up with them and they're just...
0:54:44 > 0:54:49for two or three miles, some of them, and you think, "Where are you going?
0:54:49 > 0:54:52"Are you late for the cinema? Is the fishmonger shutting?"
0:54:52 > 0:54:55I don't really get it, but this is when they're cutting corners.
0:54:55 > 0:54:58Otters on a mission. He knows what he's on about.
0:54:58 > 0:55:01OK.
0:55:01 > 0:55:05O0h, it's a bit deep there, Martin. You have to go tiptoes.
0:55:05 > 0:55:09- That is the classic otter hole. - That is an otter hole.
0:55:09 > 0:55:12Yeah, it's a hole in the root system of an ash tree,
0:55:12 > 0:55:14which the otters love to dig up into.
0:55:14 > 0:55:18So where's the entrance? Is the entrance that bit there where it's sort of a bit muddy?
0:55:18 > 0:55:20Yeah, and you can just see the hole in there.
0:55:20 > 0:55:22There's not just one here either.
0:55:22 > 0:55:24So there's another one 200 metres down there...
0:55:24 > 0:55:27- Right.- ..under a hazel tree. And all the way up the river,
0:55:27 > 0:55:29every few hundred metres, there's another one.
0:55:32 > 0:55:33That's a classic rock -
0:55:33 > 0:55:37the otter is going to come up, he can go out and poo on there.
0:55:39 > 0:55:41Oh, look at that. Hey-hey!
0:55:41 > 0:55:45- Ooh.- Isn't it lovely?- Look at that!
0:55:45 > 0:55:47Now, most otter scientists and enthusiasts,
0:55:47 > 0:55:50they like to pick it up and move it around in their hands.
0:55:50 > 0:55:54Not me. I use a stick.
0:55:54 > 0:55:56Are you listening, Chris Packham?
0:55:56 > 0:56:01- OK, so you can see they've been eating crayfish here.- Look at that.
0:56:01 > 0:56:04The big bits of shell, and that's why it's red.
0:56:04 > 0:56:06Well, here's the crayfish, but this is very different.
0:56:06 > 0:56:07It's green, for a start.
0:56:07 > 0:56:09It's very fresh and it's green.
0:56:09 > 0:56:14- They've been eating fish here.- I can see little fish bones inside that.
0:56:14 > 0:56:17This is... I mean, it's almost still wet
0:56:17 > 0:56:20so you're talking within the last 48 hours.
0:56:20 > 0:56:23And, interestingly, sometimes you find these
0:56:23 > 0:56:27and they've got bits of moor hen in them. They love moor hen.
0:56:27 > 0:56:28This is a signalling system
0:56:28 > 0:56:31so they're going to drop a little bit here and a little bit further up
0:56:31 > 0:56:32- and a little bit further up.- Yeah.
0:56:32 > 0:56:35I mean, they don't sit there for 15 minutes reading National Geographic.
0:56:35 > 0:56:38MARTIN LAUGHS
0:56:39 > 0:56:40Are there any final tips?
0:56:40 > 0:56:44- Well, if you want to see an otter... - I do, I do.
0:56:44 > 0:56:46..you've got to get the wind direction right.
0:56:46 > 0:56:49So what you want is you want the wind coming off the otter
0:56:49 > 0:56:52and blowing into your face and if you do that
0:56:52 > 0:56:55- you've got a pretty good chance of seeing one.- Brilliant.
0:56:58 > 0:57:02There we are - the Springwatch Guide to Otters.
0:57:02 > 0:57:06We've learnt what an otter is, where it lives,
0:57:06 > 0:57:09what it gets up to on our coasts and rivers...
0:57:11 > 0:57:13..even in our cities.
0:57:13 > 0:57:17We know its history, and, most importantly,
0:57:17 > 0:57:19how to go about seeing one.
0:57:21 > 0:57:25But there is one last question.
0:57:25 > 0:57:28Did I, during the making of this film,
0:57:28 > 0:57:31get to see an otter for myself?
0:57:32 > 0:57:33Yes!
0:57:33 > 0:57:35Charlie, Charlie, Charlie!
0:57:35 > 0:57:37- I just saw an otter!- No! - I swear to you.- Where?
0:57:37 > 0:57:40I just saw an otter swimming straight towards us up here.
0:57:44 > 0:57:47Just literally in this pool here!
0:57:47 > 0:57:50- It was coming straight towards us. - Did it see us?
0:57:50 > 0:57:53Yes, because it was only there, feet away from us.
0:57:53 > 0:57:56The first time in my whole life.
0:57:56 > 0:57:59We've been here two minutes!
0:57:59 > 0:58:02But I've only seen about five otters here in the daytime
0:58:02 > 0:58:03in my whole life living.
0:58:03 > 0:58:06It was an otter in that pool not 20 feet away
0:58:06 > 0:58:08from where we are right now.
0:58:08 > 0:58:13I never dreamt I would see a river otter for myself
0:58:13 > 0:58:16and we'd only been there about two minutes.
0:58:16 > 0:58:19It just shows it can happen.
0:58:19 > 0:58:21But I promise you one thing -
0:58:21 > 0:58:25if you ever get to see a wild otter for yourself,
0:58:25 > 0:58:28you will remember it for the rest of your life.
0:58:44 > 0:58:47Subtitles by Red Bee Media Ltd