0:00:05 > 0:00:07BIRD SQUAWKS
0:00:10 > 0:00:1560 million years ago, on the shores of this tropical island,
0:00:15 > 0:00:17an extraordinary story began.
0:00:18 > 0:00:22The waves brought ashore an odd band of survivors...
0:00:22 > 0:00:28a few ancient creatures that had been accidentally swept across hundreds of miles of ocean
0:00:28 > 0:00:32from a distant land.
0:00:32 > 0:00:36They found themselves here, in a place unlike any other.
0:00:46 > 0:00:52Totally cut off from the rest of the world, these castaways made this island their own,
0:00:52 > 0:01:00gradually evolving into a collection of wildlife that's strange, rare and utterly unique.
0:01:08 > 0:01:14So rare that more than 80% of the species are found nowhere else on earth.
0:01:16 > 0:01:18The island was Madagascar.
0:01:18 > 0:01:22This is the story of what happens when a set of animals and plants
0:01:22 > 0:01:26are cast away on an island for millions of years.
0:01:26 > 0:01:31This is how this curious wonderland came into being.
0:01:54 > 0:01:57It had all begun millions of years earlier
0:01:57 > 0:02:03when a great slab of land broke apart to form the continents as we know them today.
0:02:03 > 0:02:10Africa went one way, and India went the other, and an orphaned chip of land was cast adrift,
0:02:10 > 0:02:14and ended up hundreds of miles from the nearest land.
0:02:17 > 0:02:23Its unusual geological history, its isolation, and its resting place in the tropics,
0:02:23 > 0:02:25were to shape Madagascar's fortunes.
0:02:27 > 0:02:34It's the world's oldest island, and it's had time to develop an astonishing range of landscapes.
0:02:34 > 0:02:37It's split in two by a spine of mountains
0:02:37 > 0:02:43that runs its entire length, and each side has its own character.
0:02:44 > 0:02:50On the western side lie huge forests populated with strange, bulging trees.
0:02:55 > 0:03:00Further south, an alien world... a parched and sandy wilderness,
0:03:00 > 0:03:06with an immense lake of salt, and gnarled and twisted spiny woodlands.
0:03:13 > 0:03:18And on the eastern side, lush jungle drenched in rain.
0:03:31 > 0:03:36It's this combination of long isolation and varied landscapes
0:03:36 > 0:03:42that's created the eccentric diversity of wildlife which makes this island so special.
0:03:44 > 0:03:48These rainforests are unlike any other rainforest on earth,
0:03:48 > 0:03:52and they are home to Madagascar's most successful inhabitants.
0:03:54 > 0:03:56They are lemurs.
0:04:00 > 0:04:04There are 80 different types, from nocturnal, mouse-sized creatures
0:04:04 > 0:04:09to this, the biggest, the size of a child. It's an indri.
0:04:15 > 0:04:19They are direct descendents of those first primitive mammals
0:04:19 > 0:04:25that had washed in from Africa by chance, and now they live nowhere else.
0:04:26 > 0:04:29PIERCING SQUEAL
0:04:31 > 0:04:33CALL IS ANSWERED BY OTHERS
0:04:38 > 0:04:41They have almost dog-like faces.
0:04:41 > 0:04:44But they are primates, related to us.
0:04:44 > 0:04:47And when you watch them, you can see it.
0:04:47 > 0:04:50They are highly social.
0:04:50 > 0:04:55At two years old this young male is an adolescent, but he's still close to his mother.
0:04:59 > 0:05:02His little sister is just six months old.
0:05:02 > 0:05:06This family group will stay together for several more years.
0:05:10 > 0:05:14Lemurs also have the grasping hands and feet of all primates.
0:05:14 > 0:05:17It's fundamental for a life in the trees...
0:05:18 > 0:05:23as well as an effective way to put a stranglehold on an older brother.
0:05:29 > 0:05:32For an indri, childhood is long.
0:05:32 > 0:05:35It's nine years before they are fully adult.
0:05:35 > 0:05:41There's plenty of time for play, and perfecting their impressive jumping skills.
0:05:41 > 0:05:45And perhaps even a spot of showing off.
0:06:20 > 0:06:24Everywhere you look, Madagascar has echoes of elsewhere...
0:06:24 > 0:06:29at first glance similar, but with different origins.
0:06:31 > 0:06:37On the rainforest floor, an animal emerges that might be mistaken for a hedgehog.
0:06:44 > 0:06:49But she's only the most distant relation. She's a tenrec,
0:06:49 > 0:06:52another of Madagascar's own inventions.
0:06:53 > 0:06:56And these are her youngsters.
0:07:00 > 0:07:02Dozens of them.
0:07:02 > 0:07:06Tenrecs have the distinction of giving birth to more babies than any other mammal on earth -
0:07:06 > 0:07:09as many as 32.
0:07:15 > 0:07:21Her babies are stripy, the better to hide in the shadows of the rainforest floor.
0:07:37 > 0:07:41Their ancestors too had washed in from Africa and, like the lemurs,
0:07:41 > 0:07:46they have diversified into many different species.
0:07:57 > 0:08:01As well as being Madagascar's equivalent of hedgehogs, tenrecs
0:08:01 > 0:08:05also take the place that moles and shrews would occupy
0:08:05 > 0:08:07anywhere else in the world.
0:08:14 > 0:08:19Madagascar's rich forests have been isolated from outside influence for so long,
0:08:19 > 0:08:26they have become an evolutionary cauldron, producing increasingly extreme forms of life.
0:09:07 > 0:09:10And none are stranger than this.
0:09:14 > 0:09:17It's a giraffe-necked weevil,
0:09:17 > 0:09:19and this is a male.
0:09:22 > 0:09:26And this is the reason for his extra long neck.
0:09:26 > 0:09:29He uses it for fighting.
0:09:36 > 0:09:44Meanwhile a female weevil, who's not quite as long-necked, is beginning an ambitious construction project.
0:09:44 > 0:09:49She's snipping through the leaf's veins, and making little creases in it.
0:09:55 > 0:09:59She also appears to referee the fight.
0:10:09 > 0:10:12She finally mates with the winner.
0:10:19 > 0:10:26Then, using her powerful legs, the female starts to fold the leaf in half.
0:10:28 > 0:10:31She then curls up the end,
0:10:34 > 0:10:38and inside the curl, she lays a single egg.
0:10:43 > 0:10:50All around the rainforest edge, females are busy rolling and curling their leaf nests.
0:10:53 > 0:10:56Each seems to have her own design.
0:11:07 > 0:11:14Only in these particular rainforests, and only on this one particular type of soft leaf,
0:11:14 > 0:11:17are conditions right for her to make her nest.
0:11:17 > 0:11:20It's an astonishingly specific behaviour.
0:11:23 > 0:11:28The expectant fathers are apparently just getting in the way.
0:11:33 > 0:11:38But they may be guarding against tiny insects that would parasitise the newly laid egg.
0:11:44 > 0:11:48The female has bitten tiny notches along the leaf's ribs,
0:11:48 > 0:11:53to form a kind of Velcro strip to help all it stick together.
0:11:55 > 0:11:58A few final folds,
0:11:58 > 0:12:03and the nest is complete.
0:12:03 > 0:12:07When she finally snips the leaf roll off,
0:12:07 > 0:12:09it falls to the forest floor to hatch.
0:12:18 > 0:12:22All that effort for just one egg.
0:12:28 > 0:12:31Madagascar has had a turbulent past.
0:12:31 > 0:12:39At its birth it was ripped from India and Africa, and the geological upheavals have continued since.
0:12:46 > 0:12:50The north of the island is speckled with slumbering volcanoes.
0:12:52 > 0:12:57On the forested slopes lives another Madagascar speciality.
0:13:02 > 0:13:04A chameleon!
0:13:05 > 0:13:10Chameleons weren't amongst those pioneering castaways.
0:13:10 > 0:13:12Theirs is a different story.
0:13:12 > 0:13:17It's thought that they evolved here in Madagascar itself.
0:13:18 > 0:13:22They are wonderfully adapted to a life in the trees.
0:13:22 > 0:13:26Their toes are fused, so their feet grip like tongs,
0:13:26 > 0:13:30and the arrangement of their legs is unusual for a reptile...
0:13:30 > 0:13:32they're beneath their body.
0:13:32 > 0:13:36This allows them to walk on branches thinner than their body.
0:13:46 > 0:13:48A male panther chameleon,
0:13:48 > 0:13:50one of the biggest.
0:13:54 > 0:13:58A second male is in his tree.
0:13:58 > 0:14:01He won't like that.
0:14:01 > 0:14:03If the intruder doesn't back down, there will be trouble.
0:14:20 > 0:14:24They are evenly matched - it's neck and neck.
0:14:33 > 0:14:35HISSING
0:14:49 > 0:14:54The territory holder wins, and the loser takes the quickest way out.
0:15:12 > 0:15:17In these isolated forests, chameleons have taken a variety of paths,
0:15:17 > 0:15:21and have diversified to an astonishing degree.
0:15:23 > 0:15:28Some are miniatures, and have the rich forest floors to themselves.
0:15:35 > 0:15:39A pygmy chameleon, the world's tiniest reptile,
0:15:39 > 0:15:44tiptoes through the leaf litter on the steep volcanic slopes.
0:15:50 > 0:15:54She's so tiny, she's scarcely bigger than an ant.
0:15:58 > 0:16:03And over here, in a forest of toadstools, a male.
0:16:08 > 0:16:10He's looking for her.
0:16:16 > 0:16:19He's even smaller than she is.
0:16:19 > 0:16:23Finding a mate in a giant world is challenging.
0:16:29 > 0:16:34And it's somewhat hazardous, when you could get run over by a millipede.
0:16:51 > 0:16:57It takes a while, but when he finally reaches her, he has a special tactic.
0:16:59 > 0:17:01He's not going to let go.
0:17:35 > 0:17:36They're not mating,
0:17:36 > 0:17:40simply riding around until the time is right.
0:17:40 > 0:17:44He barely touches her... just an occasional gentle little sway.
0:17:51 > 0:17:54They can go round like this for days.
0:17:55 > 0:17:58But at least they won't lose each other
0:17:58 > 0:18:01in their big volcanic forest.
0:18:07 > 0:18:12The heart of Madagascar still rumbles with geological activity.
0:18:12 > 0:18:17The centre of the island is a wide plateau of uplifted rock.
0:18:17 > 0:18:21Here there are still thousands of earthquakes every year.
0:18:30 > 0:18:32Over aeons of time,
0:18:32 > 0:18:36millions of these tiny earthquakes have torn a vast hole
0:18:36 > 0:18:41right in these central uplands, forming this, Madagascar's biggest lake...
0:18:41 > 0:18:43Lac Alaotra.
0:18:46 > 0:18:52Around the edges of this massive body of water, there are reed beds.
0:18:55 > 0:18:58But the vegetation is not fixed.
0:18:58 > 0:19:02It floats in great mats in water three metres deep.
0:19:05 > 0:19:08It's tricky and inaccessible to most.
0:19:08 > 0:19:13But one creature has adapted to live here, and only here.
0:19:25 > 0:19:29This is the Lac Alaotra reed lemur.
0:19:31 > 0:19:39Not only is it small enough to climb the thinnest reeds, it can also survive on a diet of tough grass.
0:19:39 > 0:19:43Unusually for a primate, it lives its whole life over water.
0:19:43 > 0:19:46And it only lives on this one lake.
0:19:58 > 0:20:03This family group has a patch of reeds to themselves.
0:20:14 > 0:20:16But they have a problem -
0:20:16 > 0:20:21to find enough to eat, you have to move from reed bed to reed bed,
0:20:21 > 0:20:25and that takes skill and practice.
0:20:31 > 0:20:35These lemurs can swim, but they prefer not to.
0:20:35 > 0:20:39So they have developed a special technique for crossing the reed beds
0:20:39 > 0:20:41without ending up in the water below.
0:20:46 > 0:20:49Their mother is an old hand.
0:20:49 > 0:20:54Even with a baby on her back, she is surefooted, and her older children are getting the hang of it.
0:22:22 > 0:22:24These lemurs are so specialised
0:22:24 > 0:22:27that they would struggle to live anywhere else.
0:22:29 > 0:22:33While Madagascar's centre was shaped by volcanic fire,
0:22:33 > 0:22:37the western side of the island has an entirely different story.
0:22:39 > 0:22:46For millions of years, this landscape was drowned, and layers of limestone formed underwater.
0:22:46 > 0:22:50When the ocean finally retreated, this is what was left.
0:22:50 > 0:22:54It's a gigantic, ancient reef.
0:22:59 > 0:23:04The seabed was pushed up, creating a great block of limestone.
0:23:04 > 0:23:08Over time, it's been carved by water into forests of giant pinnacles.
0:23:08 > 0:23:14This is the Tsingy - one of Madagascar's strangest landscapes.
0:23:14 > 0:23:19Underneath, it's riddled with caves, dissolved away by underground rivers.
0:23:24 > 0:23:29In places the limestone has collapsed, creating deep canyons,
0:23:29 > 0:23:35and in among them have grown little oases of forest, filled with oddities.
0:23:49 > 0:23:52The isolated forests are rich sources of food,
0:23:52 > 0:23:54but not easy for outsiders to reach.
0:23:54 > 0:24:01The great walls of rock make moving between them, across razor sharp blades of stone, seem impossible.
0:24:06 > 0:24:10Not so. This too is the haunt of lemurs.
0:24:10 > 0:24:17This most diverse group of primates has adapted to thrive all over the island, even here.
0:24:20 > 0:24:23These are crowned lemurs.
0:24:33 > 0:24:36They don't live up here, but they must cross the peaks
0:24:36 > 0:24:40to find fruiting trees in the forest pockets.
0:25:14 > 0:25:18Exposed to the tropical sun, it's devilishly hot.
0:25:31 > 0:25:37The group seeks shelter and a brief respite.
0:25:45 > 0:25:49The lemurs are vulnerable here,
0:25:49 > 0:25:52and need to get a move on.
0:26:07 > 0:26:10There's still a way to go before they reach the forest.
0:26:25 > 0:26:30They get to what looks like the most daunting part of the journey -
0:26:30 > 0:26:36a 30-metre drop where the limestone has fallen away to create sheer cliffs.
0:26:40 > 0:26:44But crowned lemurs are as good at rock climbing as they are at tree climbing.
0:26:57 > 0:27:04Once down, they'll find shelter from the heat and plenty to eat.
0:27:04 > 0:27:06But they must be on their guard.
0:27:12 > 0:27:16There is one danger that every lemur on the island fears,
0:27:16 > 0:27:20a hunter that climbs as well as they can -
0:27:20 > 0:27:21the fossa!
0:27:24 > 0:27:27No big African predators made it to Madagascar.
0:27:27 > 0:27:30There are no lions, no leopards, no wild dogs.
0:27:30 > 0:27:36Instead the island's top predator is a giant mongoose.
0:27:36 > 0:27:39And it eats lemurs.
0:27:43 > 0:27:47But it has more curious habits.
0:27:47 > 0:27:54It's the mating season, and this female has stationed herself 15 metres up a tree.
0:27:54 > 0:28:00She's chosen a branch that will just support her own weight, plus that of a male.
0:28:05 > 0:28:10A male approaches. If she approves of him, she'll allow him to mate.
0:28:10 > 0:28:15If she doesn't, she'll back away to a thinner branch, and he won't be able to get to her.
0:28:20 > 0:28:23She's only fertile for a few days a year,
0:28:23 > 0:28:31so setting herself up in this tall tree is a good way of advertising her availability to suitors.
0:28:31 > 0:28:36And it seems to work. This is the sixth male she's entertained today.
0:28:48 > 0:28:53The great diversity of Madagascar's wildlife is driven
0:28:53 > 0:28:57not only by the variation in landscape but also by the climate.
0:29:00 > 0:29:06The spine of mountains running the length of the island blocks the rain blowing in from the east.
0:29:06 > 0:29:12While the east coast is drenched year-round, the west lies in a rain shadow.
0:29:15 > 0:29:20The plants that have evolved here have had to adapt to an arid world.
0:29:20 > 0:29:25Some places get less than a tenth of the rain that falls in the rainforests of the east.
0:29:27 > 0:29:31This is the land of the baobab.
0:29:31 > 0:29:37These bizarrely shaped trees evolved to store water in their trunks.
0:29:37 > 0:29:42They are tough and can live to a great age.
0:29:42 > 0:29:45This baobab may be over 1,000 years old.
0:29:48 > 0:29:53In these desiccated landscapes, many plants have evolved
0:29:53 > 0:29:56these bloated trunks to store water for the driest times.
0:30:00 > 0:30:03The west of the island is dotted with these fat oddities.
0:30:03 > 0:30:09Many survive by just clinging with long roots to cracks on bare rock.
0:30:19 > 0:30:24Like most plants here, this uncarina stores water in its stem.
0:30:24 > 0:30:30And it is also economical with its flowers, putting out a few a day, over several months.
0:30:30 > 0:30:37This gives maximum opportunity for pollinators to visit.
0:30:37 > 0:30:41But this is not what the uncarina needs,
0:30:41 > 0:30:45a sunbird has become a nectar thief.
0:30:45 > 0:30:50Piercing the base of the flower it by-passes the pollen entirely.
0:31:00 > 0:31:03But the sunbird is not alone.
0:31:41 > 0:31:46Unfortunately for the shrub, it's another flower bandit.
0:31:46 > 0:31:50In a place as tough as this, a flower is well worth the effort.
0:32:07 > 0:32:11Madagascar is 1,000 miles from end to end.
0:32:11 > 0:32:19The variation from north to south is extreme, and the further south you go, the drier it gets.
0:32:21 > 0:32:25Most of the time, the rivers here are barely ankle deep.
0:32:30 > 0:32:32But there's just enough water and nutrients
0:32:32 > 0:32:34for a fringe of forest to take hold.
0:32:34 > 0:32:39And in Madagascar, where there's forest, there are lemurs.
0:32:41 > 0:32:43These are sifakas.
0:32:43 > 0:32:48They are superb acrobats, adapted to leaping from trunk to trunk.
0:32:51 > 0:32:56But where the gap is too great or in more open stretches of river bank,
0:32:56 > 0:33:00they abandon the trees and do something extraordinary.
0:33:08 > 0:33:15Their hind legs are too long to walk on all fours, so they stay upright, and gallop.
0:33:20 > 0:33:25These river forests are an oasis in this dry landscape.
0:33:25 > 0:33:29That can lead to some spectacular competition for territory.
0:33:29 > 0:33:35A female paradise flycatcher is busy building a nest.
0:33:35 > 0:33:39Both male and female have red feathers,
0:33:39 > 0:33:41but the males are particularly striking,
0:33:41 > 0:33:45with long tail plumes and bright blue rings round their eyes.
0:33:49 > 0:33:55Curiously, although all males start out with red feathers, some males turn completely white.
0:33:55 > 0:34:00No-one knows why, but it's something that's exceedingly rare in birds.
0:34:00 > 0:34:02Another Madagascar oddity.
0:34:06 > 0:34:10The red female and her white partner construct the nest between them.
0:34:18 > 0:34:21It's a delicate affair, built of leaves and grasses
0:34:21 > 0:34:26woven together with cobwebs, and it takes days of careful work.
0:34:39 > 0:34:41A red male watches nearby,
0:34:41 > 0:34:46breeding territory is particularly jealously guarded.
0:34:46 > 0:34:48The white male must see him off.
0:35:07 > 0:35:11Danger averted, the couple return to work.
0:35:17 > 0:35:19But there's worse to come...
0:35:22 > 0:35:23..a drongo!
0:35:36 > 0:35:41For some reason it sets about destroying the carefully-made nest.
0:35:43 > 0:35:46There is nothing the flycatcher couple can do about it.
0:35:48 > 0:35:50SQUAWKING
0:35:50 > 0:35:54The drongo isn't even stealing the material,
0:35:54 > 0:35:57just chasing the flycatchers from their territory.
0:35:57 > 0:36:02Competition for space is that fierce.
0:36:39 > 0:36:43The female gives up and leaves.
0:36:43 > 0:36:48Maybe she'll look for a more assertive male.
0:36:58 > 0:37:02Go far enough south and the island changes once more,
0:37:02 > 0:37:06into a landscape of scrub and spines.
0:37:08 > 0:37:12This place may go years without rain.
0:37:13 > 0:37:15Strangely, there is water here.
0:37:17 > 0:37:23This vast lake is ten-miles long, and just two-metres deep.
0:37:25 > 0:37:27But it's not what it seems.
0:37:32 > 0:37:36Greater flamingos fly 250 miles from Africa to breed here.
0:37:39 > 0:37:41But they pretty much have it to themselves,
0:37:41 > 0:37:43because this is not fresh water,
0:37:43 > 0:37:45it's a salt lake,
0:37:45 > 0:37:48gradually evaporating in the heat and drought,
0:37:48 > 0:37:50and it's hostile to life.
0:38:07 > 0:38:13This whole area has been getting drier for the last 40,000 years.
0:38:13 > 0:38:18But the plants and animals here are uniquely adapted to extreme aridity.
0:38:23 > 0:38:27Mornings are surprisingly chilly.
0:38:27 > 0:38:31A rare Verreaux's coua, found only round this lake,
0:38:31 > 0:38:34puffs itself up until it's almost spherical.
0:38:44 > 0:38:47Ring-tailed lemurs sunbathe too.
0:38:47 > 0:38:49The most adaptable of all the lemurs,
0:38:49 > 0:38:52they can cope with the dryness,
0:38:52 > 0:38:56but they can't go without water entirely.
0:38:59 > 0:39:02RUSTLING AND CHIRPING
0:39:08 > 0:39:16A giant fig, surprisingly and persistently green, wafts its thirsty roots across the ground.
0:39:16 > 0:39:19There's water here somewhere,
0:39:19 > 0:39:20but it's hidden.
0:39:29 > 0:39:34It's part of a southern river system that flows underground here,
0:39:34 > 0:39:37carving holes into the limestone like a Swiss cheese.
0:39:37 > 0:39:40But it can only be reached in a few places.
0:40:06 > 0:40:12For the ringtails, it's a life-line, and they visit every day.
0:41:02 > 0:41:05In the water, too, there are curiosities...
0:41:05 > 0:41:07strange white fish,
0:41:07 > 0:41:10found only in these caverns.
0:41:10 > 0:41:14They have been trapped in these underground rivers for millennia,
0:41:14 > 0:41:16and they too have gone their own way.
0:41:21 > 0:41:23They have not only lost all their pigment,
0:41:23 > 0:41:26they've lost their eyes too.
0:41:31 > 0:41:34They also swim upside down.
0:41:34 > 0:41:37This may be to help them feed on the surface,
0:41:37 > 0:41:42but in a dark world, it barely matters which way is up.
0:42:12 > 0:42:19Here in the far south of the island, the extreme conditions make this a land of rare specialists.
0:42:19 > 0:42:22There is wildlife that's found nowhere else in Madagascar.
0:42:24 > 0:42:27A little nocturnal mammal, whistling in the dark.
0:42:31 > 0:42:36It's Grandidier's vontsira, one of the world's rarest carnivores.
0:42:38 > 0:42:41They survive on a diet of almost nothing but insects.
0:42:41 > 0:42:48As the climate here dried, only the toughest and most adaptable stayed on.
0:42:48 > 0:42:54Grandidier's vontsira, able to survive on such a diet, was able to hang on.
0:42:54 > 0:42:57THEY SQUEAL
0:43:15 > 0:43:17They're sociable, and playful.
0:43:17 > 0:43:21But their lives remain largely a mystery.
0:43:25 > 0:43:31The intense dryness of this end of the island has demanded some ingenious behaviour.
0:43:31 > 0:43:38In this desert scrubland, desiccation is just as problematic for a spider as for a mammal.
0:43:38 > 0:43:42An empty snail shell would make a perfect refuge from the heat.
0:43:44 > 0:43:47But it's not safe lying on sand.
0:43:51 > 0:43:54So this spider begins an astonishing process.
0:43:54 > 0:43:59It attaches silk to the shell, and starts to haul it into a bush.
0:44:14 > 0:44:17This is the first time this has been filmed,
0:44:17 > 0:44:21and may be the first time it's even been observed in the wild.
0:44:29 > 0:44:31Each new strand is shorter than the last,
0:44:31 > 0:44:35so the shell gradually gets pulled up.
0:44:35 > 0:44:36Technique is key.
0:44:36 > 0:44:40It's important that the shell is secured from several angles,
0:44:40 > 0:44:42for maximum stability.
0:44:49 > 0:44:51This spider has got it wrong.
0:44:51 > 0:44:55And when the wind springs up, it totally loses control.
0:45:17 > 0:45:19This one shows how it should be done.
0:46:04 > 0:46:09This is the farthest southerly point of Madagascar.
0:46:09 > 0:46:14Beyond this is nothing until you reach Antarctica.
0:46:24 > 0:46:31This is the oldest, most arid and most remote landscape of all.
0:46:31 > 0:46:35The spiny trees are dwarves, bent by the wind.
0:46:37 > 0:46:41And on these windswept cliffs there are radiated tortoises,
0:46:41 > 0:46:44one of the world's most beautiful species.
0:46:44 > 0:46:47They're only found in these southern scrublands.
0:46:58 > 0:47:01A male sets off in pursuit of a female.
0:47:27 > 0:47:31He'd be able to mate with her if only he can get her to stand still.
0:47:35 > 0:47:40He uses the front of his shell to lift her back legs off the ground.
0:47:40 > 0:47:42She seems less than willing.
0:47:43 > 0:47:51It's a slow process, but radiated tortoises don't do anything very quickly.
0:47:51 > 0:47:57They don't become parents until the age of 20, and they may live to be 130.
0:47:57 > 0:48:03One legendary individual was claimed to be 188,
0:48:03 > 0:48:07which would make him the longest-living animal on earth.
0:48:09 > 0:48:13It's also one of the most endangered.
0:48:13 > 0:48:20It's hunted, and its unique spiny habitat is being destroyed, bit by bit, cut down for firewood.
0:48:29 > 0:48:32It was once abundant on Madagascar.
0:48:32 > 0:48:38Now it could well be extinct in the wild within the next 20 years.
0:48:46 > 0:48:53On this same windswept beach lie thousands of fragments of egg shells.
0:48:53 > 0:48:57These are the ancient nest sites of an astonishing creature...
0:48:57 > 0:48:59the biggest bird that ever lived.
0:48:59 > 0:49:04The elephant bird stood more than three meters tall,
0:49:04 > 0:49:10and a thousand years ago it would have roamed these spiny scrublands.
0:49:12 > 0:49:18In the warm sand it laid its huge eggs... bigger than dinosaur eggs.
0:49:18 > 0:49:25This astonishing bird only lived in Madagascar, and it was extraordinarily successful.
0:49:27 > 0:49:30But then, it totally disappeared.
0:49:30 > 0:49:37These egg fragments and bits of bone are all that remains to show it was here at all.
0:49:41 > 0:49:45Two thousand years ago, humans first came to Madagascar,
0:49:45 > 0:49:49and it seems the elephant bird started to vanish soon after.
0:49:49 > 0:49:52It's a story that's continued.
0:49:52 > 0:49:58Many of Madagascar's wild landscapes and species are under threat of disappearing forever,
0:49:58 > 0:50:04just as we are beginning to discover and understand the extraordinary diversity of life here.
0:50:07 > 0:50:14It's only during the last few decades that we've really started to appreciate this curious land.
0:50:14 > 0:50:17Let's hope it's not too late.
0:50:34 > 0:50:42Much of Madagascar's wildlife is secretive, and a challenge to find, let alone film.
0:50:42 > 0:50:49The team were keen to tell the story of a little lemur that only lives on this one remote lake.
0:50:49 > 0:50:52There are very few of them left, because they've long been hunted,
0:50:52 > 0:50:55and the reed beds where they live are being cut down.
0:50:58 > 0:51:02But in one village on Lac Alaotra, the local people have made strenuous
0:51:02 > 0:51:07efforts to save the reed lemurs, and they knew where they might be found.
0:51:07 > 0:51:12Field assistant Jonathan Fiely and cameraman Gavin Thurston set out with local
0:51:12 > 0:51:20fisherman and wildlife guide Ndrina Rajohonson, who has spent many months following the lemurs.
0:51:22 > 0:51:27The team wanted to film its specialised way of moving through these floating beds of reeds.
0:51:27 > 0:51:28Easy for the lemurs...
0:51:28 > 0:51:31not so easy for a film crew.
0:51:35 > 0:51:42In fact, in the tangled reed beds, it seemed almost impossible even to see them at all.
0:51:42 > 0:51:46They are so nimble, they simply melt away into the reeds.
0:51:49 > 0:51:55The team negotiated the channels in an attempt to track them down.
0:52:01 > 0:52:03The trouble was, there's no dry land here.
0:52:03 > 0:52:06Gavin would have to try and film them from a canoe.
0:52:06 > 0:52:11Following a cyclone, the lake was deep and the water particularly choppy.
0:52:18 > 0:52:21We're going to need a bigger boat!
0:52:21 > 0:52:25It's way too rocky, and the boat's going all over the shop.
0:52:25 > 0:52:31We've got a few toys up our sleeves... we've got a big stick, to help stabilise the canoe.
0:52:31 > 0:52:34This must look like sort of Amateurville,
0:52:34 > 0:52:38and it is quite precarious... you know, we've got sort of £40,000-worth
0:52:38 > 0:52:40of camera balanced in a rocky canoe,
0:52:40 > 0:52:44which looks like we've just hired it from the local boating lake.
0:52:44 > 0:52:47But I'm feeling positive.
0:52:47 > 0:52:51It was back to base for Plan B.
0:52:51 > 0:52:58Gavin and Ndrina decided to build a platform. But it would have to be very carefully designed.
0:52:58 > 0:53:00It turned into quite an undertaking.
0:53:14 > 0:53:17We're trying to adapt this construction,
0:53:17 > 0:53:21so that when we get out to the reeds we don't need to use any nails at all.
0:53:21 > 0:53:23I'm just worried that if they start banging the nails
0:53:23 > 0:53:26it's going to drive these animals even deeper into the reeds,
0:53:26 > 0:53:31so we're making this precarious 4-metre high platform above the water without any nails.
0:53:37 > 0:53:43At dawn the next day, the platforms were loaded up to be taken out to the reed beds.
0:53:48 > 0:53:52Getting the canoes through the tangled vegetation was hard enough.
0:53:52 > 0:53:57Moving through with the platforms was a different matter.
0:54:02 > 0:54:08And the whole operation had to be completed as quietly as possible, for fear of scaring the lemurs.
0:54:11 > 0:54:15One false move and the whole team would end up in the water.
0:54:23 > 0:54:27At last, a clear and stable view through the reed bed.
0:54:35 > 0:54:38Gavin got himself settled and started filming.
0:54:42 > 0:54:43But it wasn't easy.
0:54:43 > 0:54:46The very thing he wanted to film, the lemurs on the move,
0:54:46 > 0:54:52was limited by the fact that when they moved off, Gavin could only wait for them to return.
0:54:52 > 0:54:55It is quite frustrating really...
0:54:55 > 0:55:00because it doesn't matter how much experience you've got, with something like this...
0:55:00 > 0:55:04filming from the boat was too wobbly, and working off the platform you're
0:55:04 > 0:55:07literally stuck in one place in the hope that they'll come within sight.
0:55:07 > 0:55:10I think we'll get it, in-between that and this sort of cyclonic weather.
0:55:10 > 0:55:12THUNDERCLAP
0:55:13 > 0:55:16Just as they'd got set up, a storm was rolling in.
0:55:16 > 0:55:21The last place you want to be is on a lake, in a canoe, in a thunderstorm,
0:55:21 > 0:55:28so they paddled back as quickly as they could, and then could only wait for the storm to pass.
0:55:28 > 0:55:30That took three days.
0:55:34 > 0:55:39Finally, it dawned clear and calm.
0:55:42 > 0:55:44Things were looking more promising.
0:55:52 > 0:55:55(Gavin's just inside the reed-bed right over there.
0:55:55 > 0:55:59(We set him up about 5.20 this morning.)
0:55:59 > 0:56:05The team were in luck. The lemurs were feeding right next to where Gavin was stationed.
0:56:05 > 0:56:10With Ndrina's careful guidance, they were in the right place at the right time.
0:56:10 > 0:56:17It might look a bit Heath-Robinson, but at last Gavin was getting shots of one of the world's rarest lemurs,
0:56:17 > 0:56:22moving and feeding in the reeds, and for the first time, a mother and her baby.
0:56:27 > 0:56:33But even after ten days, they were still unpredictable.
0:56:34 > 0:56:36(It's 7 o'clock in the morning...
0:56:36 > 0:56:39(and they've gone to sleep!
0:56:39 > 0:56:42(They're just tucked down in here asleep.)
0:56:46 > 0:56:48I've really quite grown to like them...
0:56:48 > 0:56:51it's just quite sad that they are critically endangered.
0:56:51 > 0:56:55They only live in the reeds around this one lake, and there's very few small
0:56:55 > 0:57:01areas of reeds left, and if those reeds do disappear, then the lemurs are going to disappear with them.
0:57:01 > 0:57:06And I think it would be really sad to lose such a cute cuddly little lemur like that.
0:57:06 > 0:57:09These little lemurs have been pushed to the brink of extinction
0:57:09 > 0:57:13by hunting, and the gradual destruction of their reed beds.
0:57:13 > 0:57:19But the quiet determination of people like Ndrina mean that local attitudes are beginning to change.
0:57:42 > 0:57:45Madagascar is one of the poorest countries in the world.
0:57:45 > 0:57:50It's as much as most people can do to earn a basic living from the land.
0:57:50 > 0:57:54And yet it may be the passion and involvement of local people
0:57:54 > 0:58:00that is key to preserving its unique, and increasingly fragile, wild treasures.
0:58:07 > 0:58:13In the next episode we travel into Madagascar's most luxuriant landscape.
0:58:13 > 0:58:17Between the wild peaks of the eastern mountains and the tropical shore
0:58:17 > 0:58:20lies a magical world of rainforest where nature has run riot.
0:58:20 > 0:58:25It's the jewel in Madagascar's crown.
0:58:49 > 0:58:51Subtitles by Red Bee Media Ltd
0:58:51 > 0:58:53E-mail subtitling@bbc.co.uk