0:00:02 > 0:00:06One of the most remarkable animals ever to have walked the earth
0:00:06 > 0:00:07is heading for extinction.
0:00:12 > 0:00:18Now, an international team of scientists, filmmakers and explorers
0:00:18 > 0:00:23has been given unique access to the remote Himalayan kingdom of Bhutan.
0:00:23 > 0:00:26If they can find a thriving population of tigers here,
0:00:26 > 0:00:29there's a chance to bring them back from the brink.
0:00:29 > 0:00:31It's perfect tiger habitat.
0:00:31 > 0:00:34But it won't be easy.
0:00:36 > 0:00:39If a snow leopard can take down a yak,
0:00:39 > 0:00:41it certainly wouldn't struggle with me.
0:00:43 > 0:00:46It can't get any worse that this.
0:00:46 > 0:00:48THUNDER CRASHES
0:00:48 > 0:00:49Woo-hoo!
0:00:49 > 0:00:52They're taking on the wildest Himalayan rivers...
0:00:54 > 0:00:57..fighting through the deepest jungles...
0:00:57 > 0:01:00..and scaling the highest peaks.
0:01:00 > 0:01:03My lungs are burning.
0:01:03 > 0:01:05My legs are burning.
0:01:05 > 0:01:07Do I really want to do this?
0:01:07 > 0:01:11What they discover could be the key to saving this magnificent big cat.
0:01:11 > 0:01:13Can we save tigers?
0:01:13 > 0:01:15Absolutely we can save tigers.
0:01:15 > 0:01:17We will save tigers.
0:01:54 > 0:01:58Hidden in the foothills of the world's highest mountain range,
0:01:58 > 0:02:01lies the little known Kingdom of Bhutan.
0:02:05 > 0:02:10These Himalayan forests could be the tiger's last hope for survival in the wild.
0:02:14 > 0:02:19An expedition has set up camp on the banks of a river in the south of the country.
0:02:22 > 0:02:26A hand-picked team has already spent 10 days searching for tigers.
0:02:26 > 0:02:30They now have hard evidence these elusive cats are living close to base camp.
0:02:32 > 0:02:37For this phase of the expedition, they will be spreading the net wider.
0:02:39 > 0:02:43On his way to help them, is wildlife cameraman, Gordon Buchanan.
0:02:43 > 0:02:46He's spent 10 years filming big cats worldwide.
0:02:46 > 0:02:52It's amazing that we are looking out at what could be the future for tigers in the wild.
0:02:52 > 0:02:55The only chance that they've got
0:02:55 > 0:02:58are them existing in hills like this.
0:02:59 > 0:03:02He's already placed remote cameras high in the Himalayas,
0:03:02 > 0:03:06to try to capture images of tigers living at altitude.
0:03:11 > 0:03:18Now, Gordon's joining forces with Doctor Alan Rabinowitz, one of the world's foremost tiger experts.
0:03:18 > 0:03:22Alan has dedicated his life to saving tigers.
0:03:22 > 0:03:25I'm not sure tigers will be able to survive.
0:03:25 > 0:03:29I wake up wondering if there's any hope for the tiger.
0:03:29 > 0:03:33If we continue on the course we are now,
0:03:33 > 0:03:36tigers will be extinct in the wild
0:03:36 > 0:03:39easily within a couple of decades.
0:03:42 > 0:03:44With Gordon in camp, the team's reunited.
0:03:46 > 0:03:50They've worked together around the world.
0:03:50 > 0:03:55But this is their most critical mission so far.
0:03:55 > 0:03:58They have just 10 days left here.
0:03:59 > 0:04:01Alan gets Gordon straight up to speed
0:04:01 > 0:04:05with the images they've recorded close to camp.
0:04:05 > 0:04:06Oh!
0:04:06 > 0:04:09Oh, my word.
0:04:09 > 0:04:13Oh, gosh, they're beautiful.
0:04:13 > 0:04:16- There's no other animal like them. - And it walks that way.
0:04:16 > 0:04:20It walks like, "nothing bothers me, I don't have to be afraid of anything in this forest".
0:04:20 > 0:04:23It just walks that way!
0:04:23 > 0:04:26It's a promising start.
0:04:26 > 0:04:29But now, the expedition needs more detailed information.
0:04:29 > 0:04:34What I need you to do now is to get me more pieces of the puzzle.
0:04:34 > 0:04:37How many more tigers are there in this area?
0:04:37 > 0:04:41How far in the river valleys are they heading up?
0:04:43 > 0:04:47For Bhutan to offer tigers a lifeline, Alan needs to know whether
0:04:47 > 0:04:50there's a continuous population, right across the country.
0:04:50 > 0:04:57He's sent naturalist and expert tracker Steve Backshall up-river, far to the east.
0:04:57 > 0:05:01The Drangme Chhu is the biggest river in Bhutan.
0:05:01 > 0:05:04It actually starts way up in the high Himalaya.
0:05:04 > 0:05:07It flows right across eastern Bhutan.
0:05:07 > 0:05:12There are no records at all about tiger numbers in eastern Bhutan.
0:05:12 > 0:05:14Nobody knows anything about them here.
0:05:14 > 0:05:17If we could find any evidence at all of tigers here,
0:05:17 > 0:05:20that's vital information.
0:05:20 > 0:05:21Through this rugged landscape,
0:05:21 > 0:05:25river valleys are natural highways for wildlife.
0:05:25 > 0:05:27They are the best place to search for tigers.
0:05:30 > 0:05:34Steve's journey will begin at the top of the Drangme Chhu.
0:05:34 > 0:05:38He'll travel downstream, scouring the riverbanks for tiger tracks...
0:05:38 > 0:05:43right the way back to base camp, 100 kilometres away.
0:05:43 > 0:05:46That's where the proper mission begins.
0:05:46 > 0:05:50As this river snakes away from the path that we've been walking on,
0:05:50 > 0:05:54it heads into some of the most unknown territory in Bhutan.
0:05:54 > 0:05:57Down there is where we're really going to find
0:05:57 > 0:06:00some answers about the tiger and the future of the tiger in Bhutan.
0:06:02 > 0:06:05Answers need to be found, and quickly.
0:06:05 > 0:06:09Virtually nothing is known about Bhutan's vast forests,
0:06:09 > 0:06:13but we do know that elsewhere, tigers are in deep trouble.
0:06:14 > 0:06:20In the last century, the world has lost 98% of its tigers.
0:06:20 > 0:06:23Only small pockets survive.
0:06:23 > 0:06:26There could be as few as 3,000 left in the wild.
0:06:28 > 0:06:31But all hope is not lost.
0:06:31 > 0:06:33Along the foothills of the Himalayas,
0:06:33 > 0:06:36where human pressure is not so intense,
0:06:36 > 0:06:40Alan has a plan to join together fragmented tiger populations
0:06:40 > 0:06:44and give them the space they need to roam.
0:06:44 > 0:06:48It's an idea he's been working on for many years.
0:06:48 > 0:06:53The solution I have for saving tigers is to connect
0:06:53 > 0:06:55these isolated populations
0:06:55 > 0:07:01through corridors, through linkages in the landscape.
0:07:01 > 0:07:06So that some of these tigers could move between isolated fragments
0:07:06 > 0:07:10and thus the isolated fragments become part of a larger whole.
0:07:10 > 0:07:13Bhutan is the missing link.
0:07:15 > 0:07:19In India, the more isolated tiger populations have become,
0:07:19 > 0:07:21the quicker they are dying out.
0:07:21 > 0:07:25Even those living in protected reserves.
0:07:25 > 0:07:28Oxford University biologist, Doctor George McGavin,
0:07:28 > 0:07:32is heading south to India, to find out why.
0:07:38 > 0:07:42It will be a very different experience from the forests of Bhutan.
0:07:42 > 0:07:47It's really only when you're up here, that you realise just how vast
0:07:47 > 0:07:49the forest is, and, you know,
0:07:49 > 0:07:52how many tigers are roaming down there,
0:07:52 > 0:07:53I wonder.
0:07:55 > 0:07:59That's what Gordon wants to find out.
0:07:59 > 0:08:01But to estimate the density of tigers
0:08:01 > 0:08:03in the forest around base camp,
0:08:03 > 0:08:05he must draw on all his field experience.
0:08:07 > 0:08:12All along here is exactly where I'd expect to find tigers.
0:08:12 > 0:08:15That sort of lush, green grass that's growing here,
0:08:15 > 0:08:18creatures like Sambar deer will come out and feed here at night time.
0:08:18 > 0:08:20And tigers will come out and check
0:08:20 > 0:08:23if there's anything there for them to eat.
0:08:25 > 0:08:28Each tiger hunts over a huge area.
0:08:29 > 0:08:33So Gordon's decided his best chance is to blitz the forest
0:08:33 > 0:08:36with 30 remote cameras, which can record day and night.
0:08:39 > 0:08:44What we're trying to do is figure out how many tigers are in this area,
0:08:44 > 0:08:47because it'll give us an overall indication of the health
0:08:47 > 0:08:50of the tiger population in this part of Bhutan.
0:08:50 > 0:08:53So we need to distinguish one from the other
0:08:53 > 0:08:57and the best way of doing that is the stripe pattern on each side.
0:08:57 > 0:09:01They have a unique, almost fingerprint pattern that their stripes make up,
0:09:01 > 0:09:03so if we can photograph as many tigers as possible,
0:09:03 > 0:09:06we should be able to tell one from another.
0:09:12 > 0:09:18Far to the east, Steve's 10-day descent of the Drangme Chhu is about to begin.
0:09:20 > 0:09:25Dave Allardice will lead three rafts carrying the expedition's food and filming gear.
0:09:25 > 0:09:30He's navigated the biggest Himalayan rivers, and knows their dangers.
0:09:30 > 0:09:35We're going to be very careful out there. The water's running high, you can see it's snow melt.
0:09:35 > 0:09:39There's quite a lot of water, so we'll have to be careful.
0:09:39 > 0:09:41It's hard telling what's down there.
0:09:41 > 0:09:45Yeah, I guess that's the thing - we're kind of paddling off into the unknown.
0:09:45 > 0:09:48The team's found a calm spot to launch, but once they start,
0:09:48 > 0:09:52there's no escape from this steep-sided gorge.
0:09:52 > 0:09:54The nerves are going just a little bit.
0:09:54 > 0:09:58Also really, really optimistic about our chances
0:09:58 > 0:10:01of finding evidence of tigers moving through here.
0:10:01 > 0:10:05And that's our big goal, really.
0:10:05 > 0:10:09Steve and three other kayakers will scout each set of rapids
0:10:09 > 0:10:12to pick a safe route through for the rafts.
0:10:16 > 0:10:20With the river running so high, there'll be no margin for error.
0:10:26 > 0:10:30Near base camp, Gordon's setting camera traps.
0:10:30 > 0:10:33They won't trigger unless an animal walks within a few metres.
0:10:36 > 0:10:38Gordon now needs to think like a tiger.
0:10:42 > 0:10:44Let me just go up here.
0:10:44 > 0:10:47I am a tiger. I am a tiger.
0:10:47 > 0:10:51I am a tiger. Oh, no.
0:10:51 > 0:10:53I'm thinking about food.
0:10:53 > 0:10:58I'm thinking about going to a place where I can get something to eat.
0:10:58 > 0:11:01I think I'll cross here, because it's just a little leap like this.
0:11:01 > 0:11:04And I would go...
0:11:04 > 0:11:06this side of the rock.
0:11:06 > 0:11:10Maybe just right here.
0:11:16 > 0:11:19Tigers aren't the only wildlife the team's looking for.
0:11:19 > 0:11:22Bhutan's forests remain largely unexplored,
0:11:22 > 0:11:24so the expedition is compiling a report
0:11:24 > 0:11:27of all the animals that live here.
0:11:28 > 0:11:35Wildlife camera woman, Justine Evans, is walking the forest trails to see what creatures she can find.
0:11:40 > 0:11:44It's a huge forest, and I think it's just a tough place to work, you know?
0:11:44 > 0:11:46It's a tough place to get shots.
0:11:46 > 0:11:48Especially now when there's a lot of rain,
0:11:48 > 0:11:52there's a lot of food about, it's going to be a really difficult thing.
0:11:52 > 0:11:54Off we go.
0:11:59 > 0:12:03Alan will stay in camp to analyse camera trap images as they come in.
0:12:07 > 0:12:12The amount of tiger prey gives him a picture of how many tigers this forest might support.
0:12:12 > 0:12:16These camera traps, these are our eyes in the jungle.
0:12:16 > 0:12:19So far, the tiger prey that we're getting in the camera traps -
0:12:19 > 0:12:23the Sambar deer and the gaur, they look beautiful.
0:12:23 > 0:12:28But the team really wants to find tigers here.
0:12:28 > 0:12:31And right across Bhutan.
0:12:36 > 0:12:40Steve is in the east, on the wild, upper reaches of the Drangme Chhu.
0:12:43 > 0:12:46It's so rugged, so remote.
0:12:46 > 0:12:50You can see why nobody's ever penetrated into this place before.
0:12:50 > 0:12:54I mean, you could never get down these canyon walls,
0:12:54 > 0:12:58and it's just an absolute haven for wildlife.
0:12:58 > 0:13:01And hopefully, one of those will be our tiger.
0:13:04 > 0:13:07Their search has been made much harder.
0:13:07 > 0:13:10The Monsoon rains have arrived early.
0:13:13 > 0:13:17The river is high and the rapids are now treacherous.
0:13:17 > 0:13:19- I've got a big rapid to the left.- Stop!
0:13:19 > 0:13:22I'm going to stay away from them.
0:13:26 > 0:13:27- Come on!- Come on!
0:13:27 > 0:13:30Right now, tigers are the last thing on their minds.
0:13:32 > 0:13:34Keep paddling!
0:13:38 > 0:13:42- Hard right!- Keep going. Forward together again.
0:13:44 > 0:13:46Come on!
0:13:53 > 0:13:56Keep right of that one.
0:13:56 > 0:14:00Safely through the rapids, they look for a place to stop.
0:14:05 > 0:14:08Sandy beaches are where Steve hopes to find tiger footprints.
0:14:12 > 0:14:15But the rains have made his mission doubly difficult.
0:14:15 > 0:14:20You can see all of this rain just spatters off the surface
0:14:20 > 0:14:23and makes all the prints totally indistinct.
0:14:23 > 0:14:26Everything around me now, I mean, there's lots of animal prints here,
0:14:26 > 0:14:29I have no idea what any of them are.
0:14:29 > 0:14:31Some of them could have been left yesterday.
0:14:31 > 0:14:34It just makes our job almost impossible.
0:14:34 > 0:14:38We need to find a tiger track that's been left within the last hour,
0:14:38 > 0:14:40that's the only way we're going to succeed.
0:14:44 > 0:14:46The team press on.
0:14:46 > 0:14:49They will explore every beach they come across.
0:14:54 > 0:14:59100 kilometres down-river, Gordon's been dogged by rain too.
0:15:01 > 0:15:05But his search is proving more productive.
0:15:05 > 0:15:07Come and see this.
0:15:09 > 0:15:11Nice.
0:15:11 > 0:15:12Very nice.
0:15:14 > 0:15:18These are the tracks of either...
0:15:18 > 0:15:21a very small tiger or a leopard.
0:15:21 > 0:15:23These are just ultra fresh.
0:15:23 > 0:15:26Look at that - it's just literally just been made.
0:15:26 > 0:15:30These are the first big cat tracks that I've found.
0:15:30 > 0:15:34Oh, that's good. Man, I was beginning to worry,
0:15:34 > 0:15:38because there's almost nothing coming up this river bed,
0:15:38 > 0:15:40not even Sambar deer, nothing.
0:15:40 > 0:15:43And then to find this, is all the encouragement
0:15:43 > 0:15:46that I need to maybe put some remote cameras.
0:15:46 > 0:15:48We've got a big cat right here.
0:15:50 > 0:15:52Only if Gordon gets a picture of it
0:15:52 > 0:15:55can they tell whether it's a different tiger,
0:15:55 > 0:15:56or one they've already seen.
0:16:00 > 0:16:03A thousand kilometres away, in India,
0:16:03 > 0:16:06George is travelling to Bandhavgarh Tiger Reserve
0:16:06 > 0:16:10to find out why every single tiger has become so precious.
0:16:13 > 0:16:15HORN BEEPS
0:16:16 > 0:16:19Very loud horn for such a small scooter.
0:16:19 > 0:16:25India used to have lots of tigers and they were all over the place,
0:16:25 > 0:16:29and now they're just clinging on to small, isolated reserves.
0:16:29 > 0:16:33And they're surrounded by a sea of humanity
0:16:33 > 0:16:36and I don't really see how tigers
0:16:36 > 0:16:39will be able to survive in the long term,
0:16:39 > 0:16:42when they haven't got anywhere to go.
0:16:46 > 0:16:50As the population of the Indian subcontinent has exploded,
0:16:50 > 0:16:54tigers have been pushed out of their former habitat.
0:16:54 > 0:16:58Numerous protective reserves have been created,
0:16:58 > 0:17:02but tigers are now confined to far smaller ranges than they need.
0:17:03 > 0:17:08There are 27 tigers in this core,
0:17:08 > 0:17:11which is about 100 kilometres square.
0:17:11 > 0:17:17Which is the range of one male tiger in the wild.
0:17:19 > 0:17:23There's not enough space within the park boundaries.
0:17:24 > 0:17:26Inevitably, tigers wander outside,
0:17:26 > 0:17:30and into direct conflict with humans.
0:17:30 > 0:17:32Local tiger expert, Digpal,
0:17:32 > 0:17:36has been battling with this problem for over 10 years.
0:17:36 > 0:17:39What are the risks for a tiger, individual,
0:17:39 > 0:17:42if it has to go outside, if it's pushed out?
0:17:42 > 0:17:46They start killing cattle or buffalos, or whatever they get.
0:17:46 > 0:17:50So the maximum risk is the villagers.
0:17:50 > 0:17:54They poison the carcass, and that's where the poachers can also go.
0:17:54 > 0:17:55So a very high risk outside?
0:17:55 > 0:17:57Very high risk, yes.
0:17:59 > 0:18:03Tigers feed on a kill for several days.
0:18:03 > 0:18:06If they prey on cattle outside the reserve,
0:18:06 > 0:18:08angry villagers poison the carcass.
0:18:08 > 0:18:11When the tiger returns, it is doomed.
0:18:16 > 0:18:20It's a world away from the unbroken forests of Bhutan.
0:18:27 > 0:18:29Gordon is heading back to camp,
0:18:29 > 0:18:32to do a first check of his remote cameras.
0:18:36 > 0:18:39One or two casualties,
0:18:39 > 0:18:41most of them intact.
0:18:41 > 0:18:43That's how they're supposed to look.
0:18:44 > 0:18:48This is how they look once an elephant has got hold of them.
0:18:48 > 0:18:50HE LAUGHS
0:18:50 > 0:18:53Do you know what? I can probably repair that.
0:18:56 > 0:19:00But just how good has Gordon been at second-guessing the tigers?
0:19:04 > 0:19:06Oh, my gosh!
0:19:09 > 0:19:11Wow, look at that.
0:19:17 > 0:19:19Another one, another one.
0:19:21 > 0:19:24Gordon's struck gold.
0:19:24 > 0:19:29Images like this of tigers is precisely what we need.
0:19:31 > 0:19:33Just look at that.
0:19:33 > 0:19:36They are such amazing animals.
0:19:44 > 0:19:48You know, if ever there was an animal on this planet worth saving,
0:19:48 > 0:19:50it has to be the tiger.
0:20:01 > 0:20:06Gordon has four images, but they may all be the same animal.
0:20:06 > 0:20:08He'll have to leave his remote cameras recording
0:20:08 > 0:20:10until the end of the expedition,
0:20:10 > 0:20:12and then compare all the images
0:20:12 > 0:20:15to see how many different tigers are living here.
0:20:24 > 0:20:28In India, where tigers are trapped in small areas,
0:20:28 > 0:20:31George can easily see them with his own eyes.
0:20:31 > 0:20:34Look there, look at it! Oh, my God.
0:20:36 > 0:20:39Oh, look at that.
0:20:39 > 0:20:41And there are two cubs.
0:20:41 > 0:20:45There's an adult tiger, about 100 yards from the car.
0:20:45 > 0:20:51So that is a female with her two cubs, who are about a year old.
0:20:51 > 0:20:56Oh! They are beautiful, beautiful animals. Oh, look at that.
0:20:59 > 0:21:01They're practising their stalking.
0:21:04 > 0:21:06Look at that. That is so beautiful.
0:21:11 > 0:21:14It seems slightly unreal, actually, I have to say.
0:21:14 > 0:21:18I mean, seeing a tiger this close in Bhutan would be just unthinkable.
0:21:18 > 0:21:21I mean, it would never, ever happen.
0:21:28 > 0:21:31It's a privilege to view.
0:21:31 > 0:21:35But these young tigers face an uncertain future.
0:21:44 > 0:21:49When that male cub reaches a certain age, he'll have to move on.
0:21:49 > 0:21:52And it's not clear what he would do.
0:21:52 > 0:21:55He can't certainly occupy the same range as the other males in the park,
0:21:55 > 0:21:57so he'll have to go.
0:21:59 > 0:22:02It's unlikely he'll get far beyond the park boundaries.
0:22:06 > 0:22:10Even tigers within reserves are no longer safe from poachers,
0:22:10 > 0:22:12who supply the Chinese medicine market
0:22:12 > 0:22:15with tiger bones and body parts.
0:22:19 > 0:22:22Even in the isolated populations, where the big cats still survive,
0:22:22 > 0:22:25they're under great threat. They're being killed there as well.
0:22:25 > 0:22:29But if we save tigers within the last remaining isolated populations,
0:22:29 > 0:22:32we still have a problem.
0:22:32 > 0:22:34Because the long term survival
0:22:34 > 0:22:37of just an isolated population is in grave doubt.
0:22:38 > 0:22:40To avoid genetic inbreeding,
0:22:40 > 0:22:46male tigers need to roam over vast distances to find new females.
0:22:46 > 0:22:52Space is what Bhutan's forests could offer tigers along the Himalayas.
0:22:56 > 0:22:59This is just incredible.
0:22:59 > 0:23:02This fog forms over the top of the water,
0:23:02 > 0:23:04it almost looks like the river's on fire.
0:23:04 > 0:23:05Oh, it's a cave.
0:23:13 > 0:23:15It's a waterfall.
0:23:15 > 0:23:20I'll bet this is home to thousands and thousands of bats.
0:23:35 > 0:23:38While the rafting team makes camp for the night,
0:23:38 > 0:23:40Steve hunts for signs of tigers.
0:23:47 > 0:23:49OK, this is going to seem like
0:23:49 > 0:23:51the most tenuous bit of tracking out there,
0:23:51 > 0:23:55but I have been asked to record every one of the tracks
0:23:55 > 0:23:59that fits a tiger profile, no matter how degraded.
0:23:59 > 0:24:01These tracks, well, they're going in that direction,
0:24:01 > 0:24:04but that's the first one I spotted.
0:24:04 > 0:24:06They're coming back
0:24:06 > 0:24:07down here...
0:24:09 > 0:24:12..and...
0:24:12 > 0:24:14this one, I think, is the clearest.
0:24:14 > 0:24:18It's very circular,
0:24:18 > 0:24:21seems to be heading in this direction
0:24:21 > 0:24:26and these look much more like toes to me than they do hooves.
0:24:26 > 0:24:30The next thing really is just the size of it.
0:24:30 > 0:24:34That is the perfect size...
0:24:35 > 0:24:37..for a tiger track.
0:24:39 > 0:24:41There's no way you could say this was evidence,
0:24:41 > 0:24:44but Alan will be able to tell better than I can.
0:24:44 > 0:24:46So I'm just going to take this data back,
0:24:46 > 0:24:48and hopefully he'll tell us more.
0:24:48 > 0:24:53In India, George has spotted a fully grown adult male.
0:24:53 > 0:24:57There he is. Oh, God. Look.
0:24:57 > 0:25:00Look at him! Absolutely magnificent.
0:25:00 > 0:25:05Look at him, look at him. Ah, look at that.
0:25:05 > 0:25:07Look at that.
0:25:07 > 0:25:11What a magnificent beast.
0:25:11 > 0:25:14It's the most incredible animal.
0:25:14 > 0:25:16I'm hooked.
0:25:16 > 0:25:17I'm hooked now.
0:25:17 > 0:25:19TIGER ROARS
0:25:22 > 0:25:24Wow.
0:25:24 > 0:25:27It's the first time I've heard a tiger roaring like that.
0:25:32 > 0:25:35ROARING That noise is just amazing.
0:25:36 > 0:25:39Pretty emotional, actually.
0:25:39 > 0:25:42I feel very emotional.
0:25:42 > 0:25:45I'm a bit shaky, actually, after that.
0:25:49 > 0:25:53Seeing them now so close, it brings it home to me even more
0:25:53 > 0:25:58what a tragedy it would be if these animals were to ever become extinct.
0:26:05 > 0:26:08The hope is that we can help the tiger,
0:26:08 > 0:26:11which is a very adaptable animal, to increase.
0:26:11 > 0:26:14And, you know, it's not hard to do.
0:26:14 > 0:26:16It requires prey, it needs space.
0:26:16 > 0:26:22We've just got to stop hunting and poisoning and poaching
0:26:22 > 0:26:26and allow the animal to move freely.
0:26:26 > 0:26:29In reality, what you want is a massive area
0:26:29 > 0:26:32through which you can roam.
0:26:32 > 0:26:37Currently, all you've got is little fragments of original tiger habitat
0:26:37 > 0:26:41which hold a few individuals, and that won't work for very long.
0:26:41 > 0:26:45We need to join these up and I now see how it'll work.
0:26:45 > 0:26:49If you can join these areas up and tigers are able to move freely.
0:26:53 > 0:26:55With so many people living in India,
0:26:55 > 0:26:58there is little chance of linking tiger reserves.
0:26:58 > 0:27:02Along the less densely inhabited Himalayas, carefully managed land
0:27:02 > 0:27:04within a conservation corridor
0:27:04 > 0:27:09would offer tigers safe passage between isolated populations.
0:27:09 > 0:27:14Creating one giant refuge in which they can roam and breed.
0:27:14 > 0:27:16ALAN: The tiger corridor is an ambitious plan,
0:27:16 > 0:27:18but it's a very, very doable plan.
0:27:18 > 0:27:22It's become Alan's life's work.
0:27:22 > 0:27:26Nine years ago, he was diagnosed with incurable leukaemia.
0:27:28 > 0:27:30There's not enough time for me.
0:27:30 > 0:27:33I've got to spend whatever time I have left
0:27:33 > 0:27:37making sure that this tiger corridor becomes a reality.
0:27:37 > 0:27:41Making sure that tigers are saved for the future.
0:27:41 > 0:27:43I think about...
0:27:43 > 0:27:47It's really interesting, because I try not to think about
0:27:47 > 0:27:52my leukaemia, and yet it's in my mind every single day.
0:27:52 > 0:27:54It's in the back of my mind every waking hour,
0:27:54 > 0:27:56because it drives me now.
0:27:56 > 0:28:00It drives me to keep on doing what I know I do best,
0:28:00 > 0:28:03right up until I can no longer do it.
0:28:15 > 0:28:19The rest of the team is inspired to work day and night.
0:28:22 > 0:28:23Justine's trying a new tactic,
0:28:23 > 0:28:28to learn more about what lives alongside the big cats here.
0:28:28 > 0:28:32So what I'm doing now is I'm going to walk some of the trails at night.
0:28:32 > 0:28:34With these elephants.
0:28:34 > 0:28:38So I can conceal myself behind them, but also,
0:28:38 > 0:28:42their smell is quite domineering, so hopefully it will disguise my smell.
0:28:42 > 0:28:45These are all just ideas I have and they may work.
0:28:45 > 0:28:46If we cover enough distance,
0:28:46 > 0:28:49we've got a good chance of seeing some things.
0:28:49 > 0:28:52And it's just nice to be out walking in the forest
0:28:52 > 0:28:54and not sitting and waiting.
0:28:54 > 0:28:56I feel a bit more proactive.
0:29:06 > 0:29:07Deep in the forest,
0:29:07 > 0:29:11Gordon's remote cameras are a secret window into this world...
0:29:14 > 0:29:17..revealing behaviour which would never otherwise be seen.
0:29:21 > 0:29:24A sambar deer stomps his forelegs nervously.
0:29:30 > 0:29:33He's being stalked by wild dogs...
0:29:36 > 0:29:39..ruthless predators who hunt in packs.
0:29:42 > 0:29:47A wild boar investigates the camera, unaware of the shining eyes
0:29:47 > 0:29:51of a leopard just a few metres behind him.
0:29:57 > 0:30:00And the ultimate reward -
0:30:00 > 0:30:03a tiger, out hunting.
0:30:06 > 0:30:11The remote cameras free up Gordon to stalk the forest trails himself.
0:30:13 > 0:30:16This time of day is when tigers, leopards start to prowl about,
0:30:16 > 0:30:18actually probably half an hour ago,
0:30:18 > 0:30:22so I am walking along here half expecting to bump into a big cat.
0:30:22 > 0:30:25Most of the time, kills take place at night time,
0:30:25 > 0:30:28so that's why tigers start to get active round about now.
0:30:33 > 0:30:35Heavens above.
0:30:35 > 0:30:37Oh, two.
0:30:39 > 0:30:41Two porcupines.
0:30:41 > 0:30:44There's no mistaking what these creatures are.
0:30:44 > 0:30:48There's nothing in this forest you could confuse them for.
0:30:48 > 0:30:51I've actually seen a tiger with a porcupine quill
0:30:51 > 0:30:53stuck in its throat,
0:30:53 > 0:30:56so even something as prickly as this is still...
0:30:56 > 0:30:58a meal for a tiger.
0:31:00 > 0:31:03Camouflaged by the elephant's smell and sound,
0:31:03 > 0:31:06Justine is hoping that the wildlife won't noticed she's there.
0:31:08 > 0:31:10Going around with these elephants
0:31:10 > 0:31:13is the opposite of being stealthy and quiet.
0:31:13 > 0:31:17It's the opposite really of being a predator or being a tiger.
0:31:17 > 0:31:20I think it's probably a good thing for prey animals
0:31:20 > 0:31:23because we don't seem like a threat to them.
0:31:23 > 0:31:27We're not trying to stalk them or trying to be quiet,
0:31:27 > 0:31:29and they probably just think we're a herd of elephants.
0:31:32 > 0:31:36Her thermal imaging camera picks up an animal's body heat
0:31:36 > 0:31:38and makes them easy to spot in the dark.
0:31:38 > 0:31:44I've got something here. Looks like a squirrel.
0:31:44 > 0:31:47It should be climbing up.
0:31:47 > 0:31:49It's going way up.
0:31:52 > 0:31:54Wow, what was that?
0:31:54 > 0:31:57It's a flying squirrel!
0:31:57 > 0:31:58It just went flying through the frame.
0:31:58 > 0:32:02I didn't realise there were flying squirrels here.
0:32:02 > 0:32:05That's a great find.
0:32:09 > 0:32:13Far to the east, Steve is searching the banks of the river.
0:32:22 > 0:32:25It's a little bit nerve-racking
0:32:25 > 0:32:29wandering through this tall grass at night,
0:32:29 > 0:32:32knowing that this could be tiger territory
0:32:32 > 0:32:36and we could actually be being watched by a tiger right now.
0:32:41 > 0:32:43This is by far the biggest spider
0:32:43 > 0:32:46I've seen in this part of the world,
0:32:46 > 0:32:51and it is absolutely furious. Look at it reared up.
0:32:52 > 0:32:53That's wonderful.
0:32:53 > 0:32:55This is a primitive spider.
0:32:55 > 0:32:56All over the world,
0:32:56 > 0:32:57they're known as tarantulas.
0:32:57 > 0:32:58Big, hairy spiders,
0:32:58 > 0:33:00they're heavy-bodied
0:33:00 > 0:33:02with downward pointing fangs
0:33:02 > 0:33:04and he's bound to have
0:33:04 > 0:33:07small venom glands at the top here,
0:33:07 > 0:33:09and a bite from this
0:33:09 > 0:33:11would certainly really, really hurt.
0:33:11 > 0:33:13Look how angry he is.
0:33:13 > 0:33:15He's actually got...
0:33:15 > 0:33:16just hanging from one fang
0:33:16 > 0:33:19the wing from, I don't know...
0:33:19 > 0:33:20could be a termite.
0:33:20 > 0:33:23That is absolutely remarkable.
0:33:25 > 0:33:29Justine's tactics with the elephants are working.
0:33:29 > 0:33:30Very bright eye-shine.
0:33:30 > 0:33:34It's quite thick foliage in here.
0:33:34 > 0:33:39Just see if I can get closer to whatever's in here.
0:33:39 > 0:33:42It's quite hard to work out what it is exactly,
0:33:42 > 0:33:44cos it's all curled up having a snooze.
0:33:44 > 0:33:47But it looks very much like a civet to me.
0:33:50 > 0:33:54It's actually waking up now. Preening his tail.
0:33:54 > 0:33:57Oh, you can see the head much better now.
0:33:57 > 0:34:00Big yawn.
0:34:00 > 0:34:02It's definitely a civet.
0:34:05 > 0:34:07He's having a good old lick on his paw now.
0:34:09 > 0:34:12Beautiful.
0:34:12 > 0:34:15He's probably going to be busy all night and then sleep all day.
0:34:15 > 0:34:17Ah, look he's moving, he's moving.
0:34:20 > 0:34:22That's really nice.
0:34:22 > 0:34:24It's great on the thermal camera.
0:34:24 > 0:34:25You can really see the shape.
0:34:27 > 0:34:29Jump!
0:34:31 > 0:34:33He's going to jump again. There he goes.
0:34:33 > 0:34:35That was great.
0:34:35 > 0:34:40Gordon has found another pair of eyes reflected in his torchlight.
0:34:42 > 0:34:44Where are you? Oh!
0:34:44 > 0:34:46There he is, there he is.
0:34:46 > 0:34:49Oh, you beautiful little cat.
0:34:49 > 0:34:51He's been looking for the largest cat,
0:34:51 > 0:34:54but has found the smallest, a leopard cat.
0:34:54 > 0:34:57Wow, he's tiny.
0:34:57 > 0:35:01Is that a youngster? I wonder.
0:35:01 > 0:35:04Yes.
0:35:05 > 0:35:09Oh, this is what it is about.
0:35:09 > 0:35:11He's on the move now.
0:35:11 > 0:35:16He's kind of same size as a domestic cat, much longer legs,
0:35:16 > 0:35:18spotted like a leopard.
0:35:18 > 0:35:21Beautiful.
0:35:21 > 0:35:27You know these leopard cats, they'll catch small rodents,
0:35:27 > 0:35:29birds even.
0:35:31 > 0:35:32Eating grass at the moment.
0:35:34 > 0:35:37Whether it's a cat of this size
0:35:37 > 0:35:42or whether it's a cat the size of a tiger, there's just no denying them.
0:35:42 > 0:35:44They're just perfect, they really are.
0:35:59 > 0:36:03Steve's search for footprints has been frustrated by heavy rain
0:36:03 > 0:36:04so he's switched tack.
0:36:07 > 0:36:09Along the river, there's a handful of communities,
0:36:09 > 0:36:12rarely visited by outsiders.
0:36:12 > 0:36:15Steve will try to gather local intelligence
0:36:15 > 0:36:17about whether they've seen tigers.
0:36:17 > 0:36:18So we have someone.
0:36:19 > 0:36:23When was it that you saw this tiger and where?
0:36:23 > 0:36:25HE SPEAKS NATIVE LANGUAGE
0:36:29 > 0:36:34OK, this young man has seen a tiger just up here,
0:36:34 > 0:36:37down by the river, two weeks ago
0:36:37 > 0:36:39which is pretty incredible.
0:36:39 > 0:36:42And where was it?
0:36:42 > 0:36:45HE SPEAKS NATIVE LANGUAGE
0:36:45 > 0:36:47So, he saw the tiger.
0:36:47 > 0:36:50It was in the forest in the middle of the daytime,
0:36:50 > 0:36:53about 3 o'clock in the afternoon and it saw him
0:36:53 > 0:36:55and began to move away from him
0:36:55 > 0:36:59and this guy shouted at it and it ran off.
0:36:59 > 0:37:01So...
0:37:01 > 0:37:04So do you and your friends and you family see tigers often,
0:37:04 > 0:37:07many times, or is this a very unusual thing for you?
0:37:07 > 0:37:11HE SPEAKS NATIVE LANGUAGE
0:37:12 > 0:37:16Um, yeah, this is really quite striking news.
0:37:16 > 0:37:19So he wasn't on his own, there was three of them there -
0:37:19 > 0:37:22his father and someone else as well -
0:37:22 > 0:37:25so it's not like he's just kind of making it up,
0:37:25 > 0:37:28and also when I asked how often they see tigers,
0:37:28 > 0:37:31he said maybe once a month,
0:37:31 > 0:37:33sometimes every two months.
0:37:34 > 0:37:37That is absolutely extraordinary.
0:37:37 > 0:37:40There must be a phenomenal amount of tigers moving through here
0:37:40 > 0:37:42for there to be any sightings at all,
0:37:42 > 0:37:44let alone regular sightings.
0:37:44 > 0:37:48Last thing that Alan said to me before I left base camp
0:37:48 > 0:37:51was that if you get any evidence from people who live round here
0:37:51 > 0:37:53that there are tigers here -
0:37:53 > 0:37:56even just one person saying that they've seen one -
0:37:56 > 0:37:58then that's going to be massive,
0:37:58 > 0:38:01and you don't get any more definitive than that.
0:38:06 > 0:38:11Heartened by success, Steve continues on towards base camp.
0:38:18 > 0:38:24Back in camp, Alan is marking all confirmed tiger sightings on a map.
0:38:24 > 0:38:29Expedition biologist Rebecca Pradan has spent many years
0:38:29 > 0:38:30trekking through western Bhutan,
0:38:30 > 0:38:34where she's seen tigers with her own eyes.
0:38:34 > 0:38:39And when I saw that tiger, I was just pinching myself.
0:38:39 > 0:38:40Weren't you scared?
0:38:40 > 0:38:43No, it's quite a little bit far away,
0:38:43 > 0:38:48so then after some time, there's two things climb up.
0:38:48 > 0:38:55It's a little bit like a dog little bit smaller than a dog size cubs.
0:38:55 > 0:38:57Both cubs were there.
0:38:57 > 0:39:01So it was a female and two cubs? That's terrific.
0:39:01 > 0:39:04You've had more close tiger encounters than I have ever had.
0:39:04 > 0:39:07That's incredible. All of the data is now coming together.
0:39:07 > 0:39:11The fact that Rebecca has walked so much of Bhutan
0:39:11 > 0:39:15and has had first-hand sightings of tigers right in front of her,
0:39:15 > 0:39:19tiger prints right in front of her - females and cubs -
0:39:19 > 0:39:23all that is exactly the kind of data we need.
0:39:23 > 0:39:27And what this is showing is that large areas of Bhutan
0:39:27 > 0:39:31not only have tigers, but have tiger populations breeding.
0:39:31 > 0:39:34So the source population that Bhutan will provide
0:39:34 > 0:39:37for the overall Himalayan tiger corridor now
0:39:37 > 0:39:41is growing and growing as we get more and more data.
0:39:45 > 0:39:50With so many tiger populations facing a genetic dead end,
0:39:50 > 0:39:55Bhutan's extensive forests could serve as a tiger nursery,
0:39:55 > 0:40:00helping to repopulate other areas of the Himalayas.
0:40:00 > 0:40:04More than ever now I believe that Bhutan is the key
0:40:04 > 0:40:08to what I envisioned as the Himalayan corridor.
0:40:08 > 0:40:11If you think of the Himalayan corridor as a body,
0:40:11 > 0:40:14this really could be thought of as the heart,
0:40:14 > 0:40:18pumping blood out throughout the entire body, keeping it alive.
0:40:18 > 0:40:21Much of the rest of the body is starting to die.
0:40:21 > 0:40:25But this has the potential to not only keep it alive,
0:40:25 > 0:40:29but to invigorate the rest of the body.
0:40:30 > 0:40:36Up-river, Steve's expedition has come to an abrupt halt.
0:40:36 > 0:40:39Their path blocked by a near impossible rapid,
0:40:39 > 0:40:43they must judge whether there's a safe route through.
0:40:43 > 0:40:47- Looks pretty scary.- It does, doesn't it? It's quite intimidating really.
0:40:47 > 0:40:49It's a lot of water going downstream.
0:40:49 > 0:40:51How do you feel about it?
0:40:51 > 0:40:53Um...
0:40:53 > 0:40:55My concern is that if I make a mistake,
0:40:55 > 0:41:01if I roll over up here somewhere and can't get back up again
0:41:01 > 0:41:04and get thrown into that washing machine,
0:41:04 > 0:41:07- that would be, well it would be awful.- No. it wouldn't be much fun.
0:41:07 > 0:41:11It's one of those rapids, you've actually got to just pick your line,
0:41:11 > 0:41:12look exactly where you go
0:41:12 > 0:41:15and that's what you concentrate on and you just go for it,
0:41:15 > 0:41:17and make sure you nail it.
0:41:28 > 0:41:30Hard left! Hard left! Hard left!
0:41:36 > 0:41:38Come on, come on, come on!
0:41:51 > 0:41:53Agh! Whoa!
0:42:07 > 0:42:11Woo-hoo!
0:42:11 > 0:42:14OK, Steve, can you hear me?
0:42:14 > 0:42:16I can hear you fine, Dave.
0:42:16 > 0:42:20That looked like a hell of a run down the bottom, violent as anything.
0:42:20 > 0:42:23Any advice for the raft just before we head on down?
0:42:23 > 0:42:26Just power left through those waves to begin with
0:42:26 > 0:42:30and make sure you go to the side of that massive hole.
0:42:30 > 0:42:35You can't miss seeing it, but unfortunately I think you could miss and get dragged into it.
0:42:35 > 0:42:38You've just got to power on through there, I think.
0:42:41 > 0:42:44Woo! All forward.
0:43:01 > 0:43:04This river better not get any bigger than that.
0:43:04 > 0:43:06That is my absolute limit.
0:43:06 > 0:43:11But this place is out of this world.
0:43:16 > 0:43:20Back in camp, George is on bath duty.
0:43:22 > 0:43:24This is great.
0:43:29 > 0:43:33Alan has a new mission for him.
0:43:33 > 0:43:36If Bhutan is to be at the heart of a massive tiger corridor,
0:43:36 > 0:43:38the team needs to discover
0:43:38 > 0:43:42what local people think about coexisting alongside big cats.
0:43:42 > 0:43:47Alan has asked George to trek to a settlement up river.
0:43:47 > 0:43:50George this is a really, really important trip that you're taking.
0:43:50 > 0:43:52If the corridor is going to work,
0:43:52 > 0:43:55we know we've got the tigers here - the big cats -
0:43:55 > 0:43:57and we know that the young males
0:43:57 > 0:43:59are going to disperse outward from here,
0:43:59 > 0:44:02but we have to know if it can work
0:44:02 > 0:44:05once they go out into the human landscape,
0:44:05 > 0:44:07where they pass by human settlements.
0:44:07 > 0:44:10So some of the stuff that's going to be really vital
0:44:10 > 0:44:14is what people feel about living among tigers.
0:44:14 > 0:44:17If they value it? If they accept it?
0:44:17 > 0:44:19If they're angry about it?
0:44:19 > 0:44:23They're going to be one of our really important pieces to the puzzle.
0:44:28 > 0:44:31Rebecca will introduce him to the people of Yumdang,
0:44:31 > 0:44:34a small village three hours' walk away.
0:44:34 > 0:44:37Very wobbly!
0:44:37 > 0:44:38I'm very scared on the bridge.
0:44:38 > 0:44:41I thought you'd be used to this?
0:44:41 > 0:44:44No, I walk, but I'm very scared
0:44:44 > 0:44:45all the time.
0:44:47 > 0:44:50They are not alone on the forest path.
0:44:50 > 0:44:52Ah!
0:44:52 > 0:44:53I've been leeched.
0:44:53 > 0:44:55There'll be other ones, I'm sure.
0:44:55 > 0:44:57They're all God's little creatures.
0:44:57 > 0:44:59Ah!
0:44:59 > 0:45:00Look!
0:45:00 > 0:45:02How did it get on my finger?
0:45:06 > 0:45:08Even Eden has its problems.
0:45:08 > 0:45:11I mean, look at this. Every time you walk past,
0:45:11 > 0:45:14you will find a leech and they know exactly where you are.
0:45:14 > 0:45:18I'm just holding my hand out and it's hot and it's reaching out,
0:45:18 > 0:45:20it's just desperate to get to me.
0:45:22 > 0:45:25Oh! But I won't let you.
0:45:25 > 0:45:28These are monsters.
0:45:35 > 0:45:37That's going to bleed for a while.
0:45:53 > 0:45:59In the east of Bhutan, Steve's stopping at each remote community along the Drangme Chhu valley
0:45:59 > 0:46:03to ask whether they've seen tigers.
0:46:12 > 0:46:16There are many sightings, but the best is yet to come.
0:46:18 > 0:46:22Just been chatting to this guy through two separate interpreters
0:46:22 > 0:46:26because he doesn't actually speak the normal Bhutanese language.
0:46:26 > 0:46:30He's a farmer who moves around an awful lot around this area
0:46:30 > 0:46:32and has just come down with his cattle
0:46:32 > 0:46:34to a place quite close to here.
0:46:36 > 0:46:39HE SPEAKS NATIVE LANGUAGE
0:46:42 > 0:46:45He think about this, maybe, in total.
0:46:45 > 0:46:48In total when it was laid out.
0:46:48 > 0:46:50Body like this, and tail like this.
0:46:50 > 0:46:55What is actually quite interesting is that just two years ago,
0:46:55 > 0:46:58they actually found a tiger cub.
0:46:58 > 0:47:00He said it was about this size,
0:47:00 > 0:47:04so it wasn't a young tiger cub - probably a year or even more old.
0:47:04 > 0:47:08The fact that you've got a tiger that's with its mother,
0:47:08 > 0:47:11that's moving through an area like this is significant
0:47:11 > 0:47:13because it's usually the young males
0:47:13 > 0:47:15that are going to be actually travelling big distances
0:47:15 > 0:47:17to set up big territories.
0:47:17 > 0:47:20Far more likely if you've got a mother with a young cub
0:47:20 > 0:47:23that she is actually living around here somewhere,
0:47:23 > 0:47:27and that would actually be quite a dramatic discovery.
0:47:29 > 0:47:33News of breeding females in this far eastern part of the country
0:47:33 > 0:47:35is very good news indeed.
0:47:37 > 0:47:40But even in these pristine forests,
0:47:40 > 0:47:47tigers will only survive if people accept predators on their doorstep.
0:47:47 > 0:47:52You can't treat any habitat or any place on its own.
0:47:52 > 0:47:55You have to include the human element.
0:47:55 > 0:47:58And any efforts that you might do
0:47:58 > 0:48:02to conserve any particular animal or the whole habitat
0:48:02 > 0:48:05has to include a human element,
0:48:05 > 0:48:08because if you don't, your efforts are futile.
0:48:08 > 0:48:12Before getting a chance to ask any questions,
0:48:12 > 0:48:15George is welcomed into a village game of kuru,
0:48:15 > 0:48:18the local version of darts.
0:48:24 > 0:48:26You have to throw the dart
0:48:26 > 0:48:30at that object? What, from there?!
0:48:30 > 0:48:32Not from there. From there to here.
0:48:32 > 0:48:38You're throwing it from there to here? That's quite a long way.
0:48:38 > 0:48:41I'm so going to lose here!
0:48:42 > 0:48:45I love the way they indicate the target,
0:48:45 > 0:48:47going, "Here, come on, hit it, come on."
0:48:51 > 0:48:54Are you going to stand there? I haven't thrown this before.
0:48:54 > 0:48:56What if I miss?
0:48:59 > 0:49:00Oh!
0:49:02 > 0:49:06He's doing fine, because it's the first time he's playing, so that's why.
0:49:06 > 0:49:08I think he couldn't hit the target,
0:49:08 > 0:49:11but after some time, it's possible he may hit the target.
0:49:15 > 0:49:18Somehow, George's team wins.
0:49:21 > 0:49:23THEY SING
0:49:28 > 0:49:29SHE LAUGHS
0:49:31 > 0:49:33GEORGE JOINS IN CHANTING
0:49:33 > 0:49:37THEY CHANT AND CHEER
0:49:39 > 0:49:42After ten days exploring the Drangme Chhu,
0:49:42 > 0:49:45Steve and the rafting team are approaching base camp.
0:49:45 > 0:49:47During his dramatic, 100-kilometre journey,
0:49:47 > 0:49:51Steve has not only found tiger tracks,
0:49:51 > 0:49:53but has collected many eye-witness accounts
0:49:53 > 0:49:56of tigers living at several different locations along the river.
0:49:58 > 0:50:00Here they come.
0:50:08 > 0:50:10Hey, look at you.
0:50:10 > 0:50:14- Hey, Alan, how are you doing? - I'm doing great, how about you?
0:50:14 > 0:50:16- Really good.- You look great.
0:50:18 > 0:50:20Wow, this is a strange sight.
0:50:20 > 0:50:22Thank you very much.
0:50:22 > 0:50:25- How you been, buddy?- Good.- Great to see you. Was it a good trip?
0:50:25 > 0:50:28- Really good. Oh, it was absolutely incredible, yes.- Really?
0:50:28 > 0:50:30It's an amazing part of the world.
0:50:30 > 0:50:34Well, before we go, you just have to tell me did you find any evidence...
0:50:34 > 0:50:36- Yes. Yeah, yeah absolutely. - You're kidding?
0:50:36 > 0:50:39Almost everyone we spoke to had seen tigers.
0:50:39 > 0:50:42The stories were, I would say very, very strong.
0:50:42 > 0:50:45Some of them had seen them within weeks.
0:50:45 > 0:50:46- You're kidding? - No, absolutely serious.
0:50:46 > 0:50:51They said, "Yeah, they come through here quite regularly, I see their paw prints on the beach,"
0:50:51 > 0:50:54or, "Someone in my village sees one every couple of months."
0:50:54 > 0:50:59- Well, that's great. - One guy actually found a tiger cub within yards of his house.
0:50:59 > 0:51:06That's phenomenal! It's very possible there are actually populations living along that whole riverine area.
0:51:07 > 0:51:10That's great. God, great news.
0:51:13 > 0:51:15To farmers with livestock,
0:51:15 > 0:51:20news of wild predators living close by may not be so welcome.
0:51:20 > 0:51:26You obviously keep animals here, you have cows and other domestic animals.
0:51:26 > 0:51:35Have you ever heard of a case when those animals have been eaten or killed by wild animals?
0:51:43 > 0:51:46Ah, right, so if there was a wild cat,
0:51:46 > 0:51:50say a tiger was to ever kill one of your cattle, would you hunt it?
0:51:58 > 0:52:01It seems to be a very relaxed view of it.
0:52:01 > 0:52:04In other areas of the world,
0:52:04 > 0:52:07if a wild animal was to kill a cow or something,
0:52:07 > 0:52:10they would be up in arms about it.
0:52:10 > 0:52:13Everyone would be hunting it and make sure it
0:52:13 > 0:52:18ended its eating spree, so that's quite interesting.
0:52:18 > 0:52:25You believe that humans and wild animals can exist in sort of harmony?
0:52:40 > 0:52:42Bye.
0:52:44 > 0:52:47- Bye-bye.- Thank you for the food.
0:52:48 > 0:52:53Generally, it seems that they have quite a relaxed attitude towards wild animals.
0:52:53 > 0:52:56They're happy they're here, they're happy that they have them around.
0:52:56 > 0:53:00They believe that they should be in harmony with the animals
0:53:00 > 0:53:03and their habitat, and they love the forest.
0:53:03 > 0:53:07They think their forest is absolutely great.
0:53:08 > 0:53:13Such good will towards tigers is extraordinary.
0:53:13 > 0:53:15It's a hopeful sign that Bhutan
0:53:15 > 0:53:19could be at the core of a successful Himalayan tiger corridor.
0:53:22 > 0:53:27Gordon is back in camp, reviewing his remote cameras again.
0:53:27 > 0:53:30If he has tiger images from several locations,
0:53:30 > 0:53:33Alan can work out the population density in this area.
0:53:33 > 0:53:35Got nothing on this one.
0:53:35 > 0:53:39It's been fired by something but I don't know what it is.
0:53:42 > 0:53:46Up to now, he has captured four tiger shots.
0:53:48 > 0:53:52Yes! Look at that.
0:53:52 > 0:53:54You beauty.
0:53:55 > 0:53:59This is great, it really is.
0:54:03 > 0:54:05Alan is going to be very pleased with this.
0:54:05 > 0:54:09Oh, you beautiful beast, look at that.
0:54:09 > 0:54:12Cool as a cucumber. They've got a real swagger to them
0:54:12 > 0:54:16that only the king of the forest has.
0:54:16 > 0:54:19They've got a real confidence. There's nothing in this forest
0:54:19 > 0:54:21that these tigers have to fear
0:54:21 > 0:54:25and you can see it in the way that they move. Strutting around.
0:54:27 > 0:54:29The only way of distinguishing one tiger from another
0:54:29 > 0:54:32is by looking at closely at their stripes.
0:54:32 > 0:54:35Once you start looking at these tigers in detail,
0:54:35 > 0:54:38you realise that the stripe pattern is completely different.
0:54:38 > 0:54:42They are as different to each other as humans are.
0:54:42 > 0:54:44OK.
0:54:46 > 0:54:49- HE EXHALES - Very good.
0:54:57 > 0:55:00Gordon has captured 11 different tiger images.
0:55:00 > 0:55:05Now he and Alan have to distinguish one animal from another.
0:55:05 > 0:55:08Look at this one shot which we did.
0:55:08 > 0:55:11Now we compared striping patterns
0:55:11 > 0:55:16of this individual - which is a beautiful side shot -
0:55:16 > 0:55:18to that individual.
0:55:18 > 0:55:21- Another great - pretty great - side shot.- Cool.
0:55:21 > 0:55:25Pulled a single pattern out, and overlapped them.
0:55:25 > 0:55:29Perfect, like a fingerprint. Isn't that great?
0:55:29 > 0:55:33OK, that's great, except it means that those two shots are one tiger.
0:55:33 > 0:55:36This is true of several of the pictures.
0:55:36 > 0:55:37Now, there's one other shot.
0:55:37 > 0:55:41Really nice, look at that, steps over the stream.
0:55:41 > 0:55:43Good behaviour. Nice behaviour shot.
0:55:43 > 0:55:46We're comparing that to this tiger,
0:55:46 > 0:55:50coming straight, but we can look at these side stripes.
0:55:50 > 0:55:52We can overlay those sides.
0:55:52 > 0:55:54We can shift it,
0:55:54 > 0:55:56not at all.
0:55:56 > 0:56:00So here we have clear, beautiful, two individual tigers.
0:56:00 > 0:56:05Let's say out of all those shots we have, I think,
0:56:05 > 0:56:07possibly three individual tigers at least...
0:56:07 > 0:56:10- That's incredible. - ..in a 40, 50 square kilometre area.
0:56:10 > 0:56:12That's a good density.
0:56:12 > 0:56:15That's really good in this area.
0:56:15 > 0:56:20That would be about six tigers per 100 square kilometres. That's a lot.
0:56:20 > 0:56:23That's a really good density.
0:56:27 > 0:56:31Bhutan doesn't just have a handful of tigers.
0:56:31 > 0:56:35The evidence the team's collected from east to west
0:56:35 > 0:56:39points to a high natural density of this big cat,
0:56:39 > 0:56:42stretching across the southern half of the country.
0:56:48 > 0:56:52There's just one final piece of the puzzle.
0:56:52 > 0:56:55The team need to discover whether Bhutan's tigers
0:56:55 > 0:56:58are roaming into the mountainous north.
0:56:58 > 0:57:01If they are, huge areas of the Himalayas
0:57:01 > 0:57:05can be included in the proposed tiger corridor.
0:57:08 > 0:57:11Now Gordon's returning to check the remote cameras
0:57:11 > 0:57:15he left recording at high altitude at the start of the expedition.
0:57:17 > 0:57:19George will assist him.
0:57:26 > 0:57:29It's quite exciting, because all this time
0:57:29 > 0:57:30that I've been at base camp,
0:57:30 > 0:57:33the camera traps that I laid up in the Himalayas,
0:57:33 > 0:57:36they've been clicking away and recording images up there.
0:57:37 > 0:57:40The real important part of this expedition now
0:57:40 > 0:57:44is to find out if tigers can exist higher up in the Himalayas.
0:57:51 > 0:57:56In the final phase, George spots a big cat on the edge of camp...
0:57:56 > 0:57:58(It's behind you.)
0:57:59 > 0:58:02..Steve is stalked by a snow leopard...
0:58:02 > 0:58:06If a snow leopard can take down a yak,
0:58:06 > 0:58:10it certainly wouldn't struggle with me.
0:58:10 > 0:58:12And I don't know where the hell I am.
0:58:14 > 0:58:18..and Gordon makes the discovery of a lifetime.
0:58:18 > 0:58:20Oh, my gosh!
0:58:20 > 0:58:22Oh, my gosh!
0:58:42 > 0:58:45Subtitles by Red Bee Media Ltd
0:58:45 > 0:58:48E-mail subtitling@bbc.co.uk