0:00:10 > 0:00:14In the heart of Southeast Asia is an ancient kingdom...
0:00:17 > 0:00:20..with over 3,000 kilometres of coastline.
0:00:24 > 0:00:26But beyond its golden shores...
0:00:28 > 0:00:29..there are secret worlds.
0:00:37 > 0:00:39Home to mysterious creatures...
0:00:41 > 0:00:43..and forest giants.
0:00:51 > 0:00:53This is a fast-changing country...
0:00:54 > 0:00:56..where East and West collide.
0:01:04 > 0:01:08People and animals must work together to survive.
0:01:11 > 0:01:14Forming unique relationships.
0:01:18 > 0:01:20A spiritual land...
0:01:21 > 0:01:23..full of magic and wonder.
0:01:30 > 0:01:33This is Thailand.
0:01:50 > 0:01:55Thailand's north is a wild and rugged land.
0:01:56 > 0:01:58Cloaked in forest,
0:01:58 > 0:02:00hiding ancient communities
0:02:00 > 0:02:02and unexpected partnerships.
0:02:19 > 0:02:24Here, in the jungles of Phu Kao, live some unusual primates.
0:02:27 > 0:02:29Phayre's leaf monkeys.
0:02:31 > 0:02:33They live up to their name,
0:02:33 > 0:02:37eating the leaves of around 100 different types of plant.
0:02:45 > 0:02:49But this low-calorie diet means they've got to eat a lot.
0:02:51 > 0:02:53So, they need to keep moving.
0:03:08 > 0:03:12In all the hurry, youngsters risk getting lost among the greenery.
0:03:15 > 0:03:17But babies are born bright orange,
0:03:17 > 0:03:20making them easier for parents to spot.
0:03:31 > 0:03:33When he's a few months old,
0:03:33 > 0:03:37this baby will turn grey, like his parents.
0:03:37 > 0:03:40But, for now, he remains highly visible.
0:03:48 > 0:03:50Sisters and aunts share in the childcare.
0:03:51 > 0:03:54It helps them practise their parenting skills.
0:04:02 > 0:04:06But this new mother seems reluctant to release her infant.
0:04:16 > 0:04:20Being this protective doesn't allow her much time to rest.
0:04:21 > 0:04:24She's yet to learn the benefits of sharing.
0:04:38 > 0:04:39On the move again.
0:04:49 > 0:04:53It's hard work travelling in the tree tops with a baby in your arms.
0:04:55 > 0:04:57Feeding is more difficult, too.
0:05:17 > 0:05:20This mother is tired and hungry.
0:05:24 > 0:05:27And with others keen to care for her baby...
0:05:28 > 0:05:30..she accepts their help.
0:05:35 > 0:05:38Now, she can concentrate on the important task
0:05:38 > 0:05:40of eating more leaves,
0:05:40 > 0:05:43knowing her baby is in safe hands.
0:05:55 > 0:05:58In this remote region of Thailand,
0:05:58 > 0:06:02strong partnerships have long formed an essential part of life.
0:06:08 > 0:06:11Northern Thailand is a diverse landscape.
0:06:13 > 0:06:17Almost two-thirds of it is dominated by forested mountains.
0:06:22 > 0:06:27This green veil hides some of the world's rarest creatures.
0:06:28 > 0:06:30Like the leopard...
0:06:30 > 0:06:32the Malayan tapir...
0:06:34 > 0:06:35..and the binturong.
0:06:35 > 0:06:41Isolation has also protected ancient communities,
0:06:41 > 0:06:43where people and nature
0:06:43 > 0:06:45forge surprising alliances.
0:06:55 > 0:06:59Thailand's northern mountains began to form 50 million years ago,
0:06:59 > 0:07:03when Indian and Eurasian plates collided
0:07:03 > 0:07:05and the highest peak was born.
0:07:08 > 0:07:12Doi Inthanon is known as "The Roof of Thailand".
0:07:13 > 0:07:17It stands over 2,500 metres high.
0:07:23 > 0:07:27Temperatures here drop to near freezing,
0:07:27 > 0:07:30bathing the morning forest in cool, moist air.
0:07:42 > 0:07:44Beneath this sea of mist
0:07:44 > 0:07:46lies an enchanting world
0:07:46 > 0:07:50of wild woods and white-water streams.
0:08:02 > 0:08:05As water flows through this forest,
0:08:05 > 0:08:08it absorbs carbon dioxide from the soil and air,
0:08:08 > 0:08:10making it more acidic.
0:08:11 > 0:08:15It eats away at the limestone rock of the mountains,
0:08:15 > 0:08:17creating worlds within worlds.
0:08:23 > 0:08:25Over millions of years,
0:08:25 > 0:08:29streams and rivers have carved a maze of caverns.
0:08:36 > 0:08:40So far, more than 4,000 have been discovered.
0:08:46 > 0:08:50Tham Lod Cave is 50 metres tall.
0:09:12 > 0:09:18Thousands of Cook's swifts nest in its cathedral-like vaults.
0:09:18 > 0:09:20But they can't nest in peace.
0:09:30 > 0:09:33A predator prowls these walls.
0:09:35 > 0:09:40This cave racer snake is two metres long,
0:09:40 > 0:09:43helping it bridge gaps to scale this cavern.
0:09:56 > 0:09:58To escape the snake,
0:09:58 > 0:10:03the swifts build their nests in the most inaccessible places.
0:10:08 > 0:10:11At night, they keep dead still,
0:10:11 > 0:10:13hoping the danger passes.
0:10:23 > 0:10:26When dawn breaks over the mountains,
0:10:26 > 0:10:30the swifts can once more take to the safety of the air.
0:10:56 > 0:11:00As they leave the cave, their droppings rain down.
0:11:10 > 0:11:15Insect remains in the guano may be appealing to the carp,
0:11:15 > 0:11:19but others also take advantage of this fertile sprinkling.
0:11:31 > 0:11:34Anpa visits the cave most days.
0:11:36 > 0:11:39SHE SPEAKS IN OWN LANGUAGE:
0:12:00 > 0:12:03In Buddhism, heavenly favour can be earned
0:12:03 > 0:12:06by small acts of respect or kindness
0:12:06 > 0:12:08known as "making merit".
0:12:42 > 0:12:48Anpa's ritual of collecting this guano also has earthly benefits.
0:13:14 > 0:13:19This natural alliance reaffirms Anpa's spiritual beliefs,
0:13:19 > 0:13:21as well as providing valuable nitrogen
0:13:21 > 0:13:23and phosphorus for the soil.
0:13:29 > 0:13:32Traditional small-scale farming in the mountains
0:13:32 > 0:13:35requires a close connection with nature.
0:13:37 > 0:13:39So, too, does modern-day practice.
0:13:43 > 0:13:45In north-eastern Thailand,
0:13:45 > 0:13:47where there was once forest,
0:13:47 > 0:13:49there is now farmland.
0:13:49 > 0:13:51And people here still maintain
0:13:51 > 0:13:54an important relationship with wildlife.
0:14:00 > 0:14:02Mr Tanon is on a personal mission.
0:14:05 > 0:14:08By bending and breaking the spines of banana palm leaves,
0:14:08 > 0:14:11he creates new homes for a rare and secretive mammal.
0:14:26 > 0:14:29Among these dry, dead leaves,
0:14:29 > 0:14:31lives the painted bat.
0:14:35 > 0:14:39Painted bats have adopted this unusual roosting site...
0:14:40 > 0:14:44..because there's a short supply of natural forest in this region.
0:14:51 > 0:14:53HE SPEAKS IN OWN LANGUAGE:
0:15:03 > 0:15:06These bats were a rare sight.
0:15:06 > 0:15:11But 16 years ago, a breeding population was rediscovered here.
0:15:24 > 0:15:31It's easy to see why they are known locally as the "butterfly bat".
0:15:34 > 0:15:37For Mr Tanon, the reward for this partnership
0:15:37 > 0:15:42is simply to see the natural beauty of these bats on the wing.
0:16:04 > 0:16:06Sometimes all it takes
0:16:06 > 0:16:10is one person to make a difference.
0:16:29 > 0:16:30In northern Thailand,
0:16:30 > 0:16:35the lives of animals and people are deeply entwined
0:16:35 > 0:16:38and the natural world is an integral part of religion.
0:16:44 > 0:16:49Under the full moon, there's one event that happens each year,
0:16:49 > 0:16:51symbolising the letting go of past problems
0:16:51 > 0:16:54and welcoming new hope for the future.
0:17:00 > 0:17:03In Buddhist culture, sky-borne lanterns
0:17:03 > 0:17:07represent a move away from darkness into the light.
0:17:38 > 0:17:41The festivals of Yi Peng and Loy Krathong
0:17:41 > 0:17:44bring families and friends together.
0:18:03 > 0:18:06Celebrating the elements of nature,
0:18:06 > 0:18:09they honour Phra Mae Khongkha - the water goddess.
0:18:20 > 0:18:24"Loy", in Thai, means "to float"
0:18:24 > 0:18:28and small baskets, or "krathongs", fill the village river.
0:18:31 > 0:18:35These elaborate rituals help communities to live in harmony
0:18:35 > 0:18:37and show respect for the natural world.
0:18:52 > 0:18:56The connection between people and nature is a complex one.
0:18:58 > 0:19:02And there's one creature with which the people of northern Thailand
0:19:02 > 0:19:04have had an enduring relationship.
0:19:06 > 0:19:08But it has not always been a happy one.
0:19:24 > 0:19:26The Asian elephant.
0:19:27 > 0:19:31These giants can weigh up to five tonnes.
0:19:31 > 0:19:34So, you don't want to cross paths with one in thick jungle.
0:20:08 > 0:20:11This is an elephant this woman knows well.
0:20:12 > 0:20:16She was rescued by Lek from a life of toil and hardship.
0:20:21 > 0:20:24The felling of the forests for hardwood timber
0:20:24 > 0:20:26was once common in northern Thailand,
0:20:26 > 0:20:29and elephants were used as tractors.
0:20:33 > 0:20:36When logging was made illegal in 1989,
0:20:36 > 0:20:41many elephants were forced to earn their keep in the tourist industry.
0:20:45 > 0:20:49SHE SPEAKS IN OWN LANGUAGE:
0:21:13 > 0:21:16Now, Lek is working to change the lives
0:21:16 > 0:21:19of Thailand's domesticated elephants.
0:21:27 > 0:21:30She's rescuing them from illegal logging sites,
0:21:30 > 0:21:33circuses and tracking camps,
0:21:33 > 0:21:35and giving them a new life.
0:21:40 > 0:21:43Caboo suffered an injury in a logging camp
0:21:43 > 0:21:46when she was two years old.
0:21:46 > 0:21:51But she had to carry on working for another 23 years -
0:21:51 > 0:21:53until Lek came to her rescue.
0:22:12 > 0:22:17The elephants roam here without chains, meeting others,
0:22:17 > 0:22:19and forging new bonds.
0:22:24 > 0:22:29Lek's sanctuary also enables visitors to meet these giants.
0:22:31 > 0:22:34EXCITED CHATTER
0:22:46 > 0:22:48SNORTING
0:22:51 > 0:22:54THUNDER RUMBLES
0:23:00 > 0:23:05In the wild, Asian elephants live in family groups of related females.
0:23:07 > 0:23:13But these individuals have welcomed Lek to be part of the herd.
0:24:14 > 0:24:20Elephants are highly intelligent and emotional animals.
0:24:20 > 0:24:23And after years of psychological trauma,
0:24:23 > 0:24:27these individuals are now putting their trust in Lek.
0:24:44 > 0:24:47RUMBLING AND SPLASHING
0:24:47 > 0:24:49In Thailand, there isn't always the space
0:24:49 > 0:24:53to release large numbers of them back into the wild.
0:24:53 > 0:24:58So, these elephants are likely to spend the rest of their days
0:24:58 > 0:24:59in this sanctuary.
0:25:29 > 0:25:32With Lek's love and dedication,
0:25:32 > 0:25:34they'll get the care they need,
0:25:34 > 0:25:37and now have a second chance at life.
0:25:52 > 0:25:55In Thailand's northern mountains,
0:25:55 > 0:25:59there are a few places where great tracts of forest still remain.
0:26:02 > 0:26:05Especially on the border with Myanmar.
0:26:07 > 0:26:11It's the largest area of protected land in mainland Southeast Asia.
0:26:15 > 0:26:19At its heart, the wilderness of Huai Kha Khaeng,
0:26:19 > 0:26:24is home to some of Thailand's rarest and most elusive creatures...
0:26:29 > 0:26:30..such as banteng.
0:26:33 > 0:26:36They normally live deep within the forest,
0:26:36 > 0:26:37but, during the dry season,
0:26:37 > 0:26:41come out into the clearings to feed on the last remaining grasses.
0:26:43 > 0:26:48These wild cows are believed to be the ancestors
0:26:48 > 0:26:51of all cattle in Southeast Asia.
0:27:05 > 0:27:08Each herd is comprised of a male,
0:27:08 > 0:27:10several females,
0:27:10 > 0:27:12and their playful calves.
0:27:21 > 0:27:24Huai Kha Khaeng is one of the few places
0:27:24 > 0:27:27where numbers seem to be growing.
0:27:40 > 0:27:43Sambar deer also like to graze here
0:27:43 > 0:27:45and are useful sentinels,
0:27:45 > 0:27:47alert to the sounds of the forest.
0:27:49 > 0:27:51They need to be.
0:27:51 > 0:27:54Large predators live here, too.
0:28:02 > 0:28:05Armed rangers are here to protect the rarest of them all.
0:28:06 > 0:28:08The Indochinese tiger.
0:28:08 > 0:28:15It is estimated there are only 200 of these tigers left in Thailand.
0:28:15 > 0:28:17And they face extinction
0:28:17 > 0:28:20due to habitat loss and poaching.
0:28:30 > 0:28:34The rangers pass on any information they find to scientists...
0:28:36 > 0:28:40..who are also working hard to prevent the tigers' decline.
0:28:42 > 0:28:44It's a great collaboration
0:28:44 > 0:28:47between the Department of National Parks,
0:28:47 > 0:28:49Wildlife And Plant Conservation,
0:28:49 > 0:28:52and the Wildlife Conservation Society.
0:28:56 > 0:28:58But it's tough work for everyone.
0:29:00 > 0:29:03Tigers are almost impossible to find.
0:29:24 > 0:29:27The best way for Som Pot and the tiger research team
0:29:27 > 0:29:32to work out how many live here is by using camera traps.
0:29:33 > 0:29:36They've revealed that here in Huai Kha Khaeng -
0:29:36 > 0:29:39just four hours' drive from Bangkok -
0:29:39 > 0:29:41there's a significant tiger population.
0:29:50 > 0:29:53Many Thai people are unaware these secretive cats
0:29:53 > 0:29:55still exist in their country.
0:30:12 > 0:30:14To know where to put the camera traps,
0:30:14 > 0:30:17the team need to understand the tigers' territory.
0:30:19 > 0:30:22To do that, they follow a number of key individuals
0:30:22 > 0:30:25using satellite collars.
0:30:29 > 0:30:34Today, Som Pot's tracking one particular tiger.
0:30:34 > 0:30:40Its satellite collar shows it keeps returning to the same place.
0:30:41 > 0:30:44It's a good chance to get vital camera-trap footage.
0:30:53 > 0:30:55The tiger has made a kill...
0:30:57 > 0:30:59..a male sambar deer.
0:31:03 > 0:31:05They must work quickly, with minimal disturbance.
0:31:05 > 0:31:07THEY MURMUR QUIETLY
0:31:12 > 0:31:14FLIES BUZZ
0:31:22 > 0:31:24THEY SPEAK IN OWN LANGUAGE
0:31:24 > 0:31:27Later that night, the tiger returns.
0:31:37 > 0:31:42Camera-trap footage has been vital for documenting the tigers here.
0:31:44 > 0:31:48Tiger stripe patterns are like fingerprints -
0:31:48 > 0:31:50unique to each individual.
0:31:59 > 0:32:04The database shows around 70 tigers roamed these forests.
0:32:14 > 0:32:18Numbers have almost doubled in a decade
0:32:18 > 0:32:21and that's because of people like Som Pot and his team.
0:32:41 > 0:32:46Restoring natural harmony in the forests of northern Thailand
0:32:46 > 0:32:49is also vital for preserving the spiritual lives
0:32:49 > 0:32:50of the people that live here.
0:32:56 > 0:33:00These men are from the Black Lahu hill tribe.
0:33:01 > 0:33:06Their ancestors lived in the Himalayan foothills
0:33:06 > 0:33:10for over 2,000 years, settling here within the last century.
0:33:13 > 0:33:15They believe spirits dwell in this forest.
0:33:22 > 0:33:25For Papa, cooperating with them is vital.
0:33:25 > 0:33:27HE SPEAKS IN OWN LANGUAGE:
0:33:38 > 0:33:43The Black Lahu have a unique relationship with nature,
0:33:43 > 0:33:47with an animist faith that predates Buddhism.
0:33:51 > 0:33:55This tree will become a bridge to the spirit world.
0:33:58 > 0:34:01HE CHANTS, OTHERS PLAY PIPES
0:34:01 > 0:34:03An offering is made.
0:34:03 > 0:34:07THEY PLAY NOTES
0:34:07 > 0:34:11Papa believes this cord will pull his wife's lost soul
0:34:11 > 0:34:15along the tree trunk back from the forest.
0:34:15 > 0:34:16HE CHANTS
0:34:22 > 0:34:25By tying the cord around her wrist,
0:34:25 > 0:34:29the spirit doctor reconnects Nalor with her soul.
0:34:30 > 0:34:34A Lahu will never cut a spirit cord,
0:34:34 > 0:34:37wearing it until it falls off.
0:34:39 > 0:34:44This sacred connection with the forest is cause for celebration.
0:34:44 > 0:34:48MUSIC PLAYS, THEY CLAP IN TIME
0:34:54 > 0:35:00By dancing, the Lahu show their joy to their creator spirit, Gui Sha.
0:35:04 > 0:35:07The Lahus' spiritual relationship with the forest
0:35:07 > 0:35:11protects their loved ones and strengthens the community.
0:35:54 > 0:35:57These remote mountain worlds
0:35:57 > 0:36:00not only hide ancient traditions,
0:36:00 > 0:36:03they also hide age-old showdowns.
0:36:06 > 0:36:09Up here lurks one of northern Thailand's
0:36:09 > 0:36:11more surprising creatures.
0:36:13 > 0:36:15The big-headed turtle.
0:36:17 > 0:36:22As his name suggests, he has an enormous head,
0:36:22 > 0:36:24with super-sized jaws.
0:36:32 > 0:36:36Food can be hard to come by in this fast-moving water,
0:36:36 > 0:36:40but as he only needs to eat every few days, there's no real urgency.
0:36:42 > 0:36:44And he knows where he's going.
0:36:49 > 0:36:54Long claws and a muscular tail propel him upstream.
0:37:02 > 0:37:05He's a little on the slow side,
0:37:05 > 0:37:06but it helps him save energy.
0:37:12 > 0:37:15He's got to where he wants to be.
0:37:15 > 0:37:17It's now a waiting game.
0:37:29 > 0:37:33Other ancient creatures are drawn from the forest to the water.
0:37:45 > 0:37:47Freshwater crabs.
0:37:49 > 0:37:53It's likely their ancestors ended up here,
0:37:53 > 0:37:55300km from the coast,
0:37:55 > 0:37:59when the mountains formed millions of years ago.
0:38:30 > 0:38:35To a crab, the big-headed turtle looks much like a rock...
0:38:39 > 0:38:40..and that's just what he wants.
0:38:53 > 0:38:57Now those jaws make sense.
0:38:57 > 0:38:59The ideal crab cracker.
0:38:59 > 0:39:01CRUNCHING
0:39:14 > 0:39:17Over millennia, remote forest streams
0:39:17 > 0:39:20have brought these unlikely animals together.
0:39:24 > 0:39:29Thailand's mountainous north is an ancient land...
0:39:32 > 0:39:35..but there are places where people have had a big influence
0:39:35 > 0:39:37in recent years.
0:39:39 > 0:39:43Like here, in the hills of Mae Hong Son.
0:39:43 > 0:39:48Commercial logging cleared parts of this land,
0:39:48 > 0:39:52creating new opportunities for other kinds of plant.
0:40:02 > 0:40:06Sunflowers now carpet these mountains.
0:40:12 > 0:40:15They were first brought to Thailand from Central America
0:40:15 > 0:40:18as garden plants about 70 years ago.
0:40:19 > 0:40:22But no-one quite knows how they got to the slopes.
0:40:24 > 0:40:28Up here, they spread like wildfire.
0:40:38 > 0:40:41Many tourists come to admire the spectacle.
0:40:49 > 0:40:52The people of the North have embraced this interloper...
0:40:59 > 0:41:01..adopting it as a provincial mascot.
0:41:12 > 0:41:18The Mexican sunflower is now part of the fabric of northern Thailand.
0:41:30 > 0:41:34Where farmland is replacing forest,
0:41:34 > 0:41:37wildlife finds new ways to flourish.
0:41:47 > 0:41:52Weaver ants have colonised much of this man-made landscape.
0:41:57 > 0:42:02Hundreds of them work as a team to build their home out of leaves,
0:42:02 > 0:42:04protecting them against the elements.
0:42:20 > 0:42:23To lash the leaves together,
0:42:23 > 0:42:25gangs of workers pull as one.
0:42:29 > 0:42:33Bridges are built, helping ants move quickly around the site.
0:42:49 > 0:42:52To hold their construction together,
0:42:52 > 0:42:55they rely on the youngest members of the colony -
0:42:55 > 0:42:57grubs.
0:43:07 > 0:43:10When they're in their final stages of development,
0:43:10 > 0:43:12they produce strands of silk...
0:43:15 > 0:43:18..and make the perfect glue gun.
0:43:35 > 0:43:39In just a few hours, their new home is complete.
0:43:42 > 0:43:45Their nest happens to be on a mango farm.
0:43:47 > 0:43:49But it's no ordinary orchard.
0:44:00 > 0:44:04Mr Bunchu has recruited this army of miniature warriors
0:44:04 > 0:44:05to defend his fruit.
0:44:07 > 0:44:09They'll eat any pests.
0:44:12 > 0:44:16And by tying these strings between mango trees,
0:44:16 > 0:44:20Mr Bunchu helps the ants get to new foraging grounds,
0:44:20 > 0:44:22expanding their empire
0:44:22 > 0:44:24and protecting his orchard.
0:44:44 > 0:44:49Healthy ant colonies mean fewer pesticides
0:44:49 > 0:44:52and the weaver ants give the farmer something else.
0:44:55 > 0:44:58Mr Bunchu likes to harvest their eggs.
0:45:26 > 0:45:30He takes only a little from each nest,
0:45:30 > 0:45:33separating the ants so they can return to the colony.
0:45:35 > 0:45:38These eggs are a Thai delicacy...
0:45:38 > 0:45:41and a favourite dish of the North.
0:45:51 > 0:45:53By working WITH wildlife,
0:45:53 > 0:45:55farmers in northern Thailand
0:45:55 > 0:46:00are able to benefit from nature's bounty, and help it flourish.
0:46:16 > 0:46:18But the greatest rewards of all
0:46:18 > 0:46:22are found in the shadows of these northern mountains.
0:46:22 > 0:46:29The soil here is watered by rivers that flow down through this land,
0:46:29 > 0:46:30irrigating the rice fields.
0:46:38 > 0:46:42Thailand exports more than 9 million tonnes of rice a year.
0:46:51 > 0:46:55Every rice plant is vital for Mr Thipuin's crop...
0:46:57 > 0:46:59..but there's constant threat.
0:47:01 > 0:47:05White-backed plant hoppers invade the paddy fields.
0:47:10 > 0:47:14They suck the sap and stunt the growth of the rice plants,
0:47:14 > 0:47:16reducing the yield.
0:47:18 > 0:47:21But living beneath these mountains,
0:47:21 > 0:47:25the farmers have their own natural pest control.
0:47:31 > 0:47:34Every evening, it stirs.
0:47:55 > 0:47:59300,000 wrinkle-lipped bats emerge
0:47:59 > 0:48:02to hunt for insects on the wing.
0:48:25 > 0:48:31This living ribbon of bats is a welcome sight for the farmers.
0:48:31 > 0:48:33HE SPEAKS IN OWN LANGUAGE:
0:48:53 > 0:48:57It's estimated that, by eating white-backed plant hoppers,
0:48:57 > 0:48:59these bats rescue enough rice
0:48:59 > 0:49:03to feed 26,000 people in Thailand each year.
0:49:07 > 0:49:10And by planting his rice in the flight path,
0:49:10 > 0:49:14Mr Thipuin will benefit from these hungry little helpers.
0:49:18 > 0:49:22In these northern mountains, success and survival
0:49:22 > 0:49:24rely on working together
0:49:24 > 0:49:28and exploiting opportunities when they arise.
0:49:29 > 0:49:33Ancient beliefs, modern ideas,
0:49:33 > 0:49:35and unexpected alliances
0:49:35 > 0:49:39all help to maintain the natural harmony.
0:49:52 > 0:49:55The toughest challenge for the northern Thailand team
0:49:55 > 0:49:57was filming Indochinese tigers.
0:49:59 > 0:50:03There are only about 350 left in the wild.
0:50:03 > 0:50:07The only place they stood any chance of success
0:50:07 > 0:50:09was in the forest of Huai Kha Khaeng Wildlife Sanctuary.
0:50:13 > 0:50:17Producer James Hemming teamed up with the scientists
0:50:17 > 0:50:18who've devoted their lives
0:50:18 > 0:50:21to understanding the habits of these creatures...
0:50:22 > 0:50:26..sometimes using quite unusual tracking techniques.
0:50:26 > 0:50:28Yeah.
0:50:28 > 0:50:30Yeah, that's really...
0:50:30 > 0:50:31It's quite potent!
0:50:31 > 0:50:34Scent marks define tiger territory.
0:50:34 > 0:50:36They're like signposts,
0:50:36 > 0:50:40providing vital clues to their whereabouts.
0:50:44 > 0:50:45Two different tigers?
0:50:48 > 0:50:52Even so, finding them is far from easy.
0:50:54 > 0:50:57The team have only got three weeks in this forest,
0:50:57 > 0:51:00which is four times the size of Greater London.
0:51:07 > 0:51:09HE SNIFFS
0:51:09 > 0:51:12James is going to need more than a sniff to succeed.
0:51:14 > 0:51:15Wow!
0:51:15 > 0:51:16Yeah.
0:51:18 > 0:51:20Camera traps are his best chance
0:51:20 > 0:51:23of getting footage of these elusive animals.
0:51:25 > 0:51:26The cameras need to be rigged
0:51:26 > 0:51:30at key locations in the forest where they'll be triggered by motion.
0:51:33 > 0:51:34And to film a passing tiger,
0:51:34 > 0:51:37it's really important to get the frame size right.
0:51:37 > 0:51:39Pretty good.
0:51:40 > 0:51:41Yeah. It's all good.
0:51:41 > 0:51:43Cool. OK.
0:51:45 > 0:51:46THEY MURMUR
0:51:46 > 0:51:51For the scientists, camera traps have also proved essential.
0:51:51 > 0:51:56Not just for research, but in helping police with anti-poaching.
0:51:56 > 0:51:59In 2015, camera-trap images proved that a tiger
0:51:59 > 0:52:04which once roamed these forests, had been illegally poached.
0:52:04 > 0:52:07It led to the prosecution of three men.
0:52:12 > 0:52:15The crew aren't relying just on camera traps.
0:52:15 > 0:52:18Wildlife cameraman Graham MacFarlane
0:52:18 > 0:52:21and guide Kwanchi, are also in the field.
0:52:21 > 0:52:25A tiger could be ten metres from you and you wouldn't see it.
0:52:33 > 0:52:36This place is covered with animal prints.
0:52:36 > 0:52:39There's elephant, loads of deer.
0:52:39 > 0:52:41It's a really good sign, all prey for the tiger.
0:52:41 > 0:52:44I've got a really good feeling about this place.
0:52:47 > 0:52:50And there's a fresh tiger track, just down there.
0:52:50 > 0:52:54(Great news. Well spotted, Kwanchi!)
0:52:54 > 0:52:57Graham is using a more traditional method,
0:52:57 > 0:53:00waiting it out in a hide near a spring.
0:53:00 > 0:53:03So, I've got my camera there, my seat,
0:53:03 > 0:53:06my little window out on the world.
0:53:10 > 0:53:13As Graham settles in,
0:53:13 > 0:53:16the camera traps start to bring in results.
0:53:32 > 0:53:35A leopard is caught on camera.
0:53:35 > 0:53:37But no sign of tigers.
0:53:39 > 0:53:44A few days later, scientist Som Pot may have found the breakthrough
0:53:44 > 0:53:48that James needs - the rotting remains of a tiger kill.
0:53:50 > 0:53:53"Come to Thailand!" they said. "Full of beaches(!)"
0:53:53 > 0:53:55FLIES BUZZ
0:53:56 > 0:53:59The tiger could return at any time,
0:53:59 > 0:54:01so the team need to work swiftly.
0:54:01 > 0:54:05I really hope this works. It could be the best chance we have
0:54:05 > 0:54:08of actually filming a tiger here.
0:54:08 > 0:54:10Now all they can do is wait.
0:54:16 > 0:54:19Patience is also key for Graham.
0:54:21 > 0:54:23Another day in the office.
0:54:23 > 0:54:26Still no tiger. I'm not going to give up yet.
0:54:33 > 0:54:36As it's the height of the dry season,
0:54:36 > 0:54:39the spring is proving to be a busy place.
0:54:48 > 0:54:50A Malay tapir.
0:54:50 > 0:54:52Such an unusual-looking animal.
0:54:55 > 0:54:59But this binturong has Graham baffled.
0:54:59 > 0:55:02I shall have to look that one up in the mammals book.
0:55:02 > 0:55:04That's is pretty cool, though.
0:55:06 > 0:55:10And there are signs that predators may be close.
0:55:10 > 0:55:13I just saw one of those barking deers with a massive scar.
0:55:13 > 0:55:16I can only imagine it was a...lucky escape.
0:55:16 > 0:55:18Possibly from a tiger.
0:55:21 > 0:55:23It makes me nervous.
0:55:25 > 0:55:28Graham is right to be nervous.
0:55:28 > 0:55:31A ranger was recently attacked here by a tiger.
0:55:33 > 0:55:38But, right now, there's a far bigger threat that no-one had anticipated.
0:55:42 > 0:55:44A forest fire.
0:55:44 > 0:55:45Out of control.
0:55:46 > 0:55:50James and the team are forced back to base.
0:55:58 > 0:56:01It's weird, because it was quite sunny earlier...
0:56:02 > 0:56:05..and now with the wind's picked up, and it's so smoky.
0:56:07 > 0:56:10The langurs all left at the same time.
0:56:10 > 0:56:12They went that way.
0:56:12 > 0:56:13So, I guess...
0:56:15 > 0:56:18..if the fire does come this way, I'll head that way, too.
0:56:22 > 0:56:24Graham's time in the hide is over.
0:56:28 > 0:56:30Back at the headquarters,
0:56:30 > 0:56:34the fires are now dangerously close to James and the team.
0:56:36 > 0:56:41It's suddenly become, within, like, ten minutes, incredibly smoky.
0:56:41 > 0:56:43We're actually having to evacuate.
0:56:46 > 0:56:49Pretty worried, to be honest. It's just so unpredictable.
0:56:58 > 0:57:00Holy Moley...
0:57:07 > 0:57:10The team managed to get out safely,
0:57:10 > 0:57:14and despite the fires, the camera traps were saved.
0:57:18 > 0:57:19Wow...
0:57:23 > 0:57:26Look... I mean, look at the size of him.
0:57:26 > 0:57:28Fantastic. Wow...
0:57:31 > 0:57:34- It's lucky that we got this? - Yes!- Really?
0:57:36 > 0:57:39- Healthy.- Really healthy.
0:57:39 > 0:57:41- Good body condition. - Which is great.
0:57:41 > 0:57:45This must mean there's plenty of animals to, you know, hunt.
0:57:55 > 0:57:57I'm over the moon that we actually managed to,
0:57:57 > 0:57:59you know, get the footage.
0:57:59 > 0:58:03- Thank you very much. It was great. - You're welcome.
0:58:04 > 0:58:07Over the course of the last 20 years,
0:58:07 > 0:58:09tiger numbers have increased here.
0:58:09 > 0:58:14And there is new hope for Thailand's biggest land predator.