0:00:03 > 0:00:08Madagascar. An ancient island adrift in the Indian Ocean.
0:00:10 > 0:00:14Its animals and plants in isolation for millions of years
0:00:14 > 0:00:17have evolved in their own way so that now over 80% of them
0:00:17 > 0:00:21are unlike any others anywhere else in the world.
0:00:24 > 0:00:30And by far the greatest concentration of its highly specialised wildlife
0:00:30 > 0:00:35is found here, among the mountains and rainforests of the east.
0:00:46 > 0:00:53A journey down these eastern slopes from isolated mountain peaks to tropical shorelines
0:00:53 > 0:00:57reveals the huge variety of this islands' wildlife.
0:01:18 > 0:01:21160 million years ago,
0:01:21 > 0:01:24Madagascar lay between Africa and India
0:01:24 > 0:01:28within a much larger super-continent called Gondwana.
0:01:30 > 0:01:33As this giant landmass slowly broke apart,
0:01:33 > 0:01:38the upheavals created a 1,000-mile-long range of mountains
0:01:38 > 0:01:41that stretched the length of Madagascar.
0:01:43 > 0:01:47Separating west from east, the Andringitra Highlands
0:01:47 > 0:01:50are one of the high points along this rocky backbone.
0:01:53 > 0:02:01Over 2,500 metres high, they rise like inland islands far above the surrounding plains.
0:02:14 > 0:02:22Over an immense span of time, these huge granite domes and plateaux have been sculpted by the elements.
0:02:27 > 0:02:34The climate on these isolated tops is the most extreme found on this tropical island.
0:02:34 > 0:02:37The days are scorching hot,
0:02:37 > 0:02:40the nights bitterly cold.
0:02:41 > 0:02:46It appears deserted, and yet there is life here.
0:02:46 > 0:02:53Usually found in warm forests, a few small troops of ring-tailed lemurs
0:02:53 > 0:02:57make their home in this desolate, windswept place.
0:03:03 > 0:03:06To combat the cold, they have evolved larger bodies
0:03:06 > 0:03:10and much thicker coats than their lowland relatives.
0:03:12 > 0:03:15And they have another trick up their sleeves.
0:03:20 > 0:03:24After spending the freezing nights huddled together in a crevice,
0:03:24 > 0:03:27they start the day with a spot of sunbathing.
0:03:33 > 0:03:39Only drought-loving plants like aloe and cactus can survive in this high-altitude desert.
0:03:44 > 0:03:51During the dry season, these succulent plants are the lemurs' only source of moisture.
0:03:51 > 0:03:54It may be a tough, hand to mouth existence,
0:03:54 > 0:03:57but they have few competitors up here.
0:03:59 > 0:04:04Even so, venturing out on these exposed summits
0:04:04 > 0:04:06is not without its dangers.
0:04:18 > 0:04:22Madagascar buzzards are quite capable
0:04:22 > 0:04:23of snatching an unwary lemur.
0:04:26 > 0:04:27LEMUR BARKS
0:04:27 > 0:04:31A barked alarm call sends them all scuttling for cover.
0:04:35 > 0:04:38BARKING CONTINUES
0:05:02 > 0:05:07Ring-tailed lemurs are just as suited to life on the ground as up in the trees,
0:05:07 > 0:05:12and that makes them far more adaptable than most of Madagascar's lemurs.
0:05:14 > 0:05:19Several troops of ring-tails manage to make a living in these highlands.
0:05:25 > 0:05:32Some of the luckier ones occupy a more sheltered valley where a few trees have managed to take root.
0:05:34 > 0:05:40Morning fog condensing on leaves is an important source of water.
0:05:44 > 0:05:49Although the mornings still have a chill to them, life here seems more relaxed.
0:05:54 > 0:05:57But also more crowded.
0:06:05 > 0:06:13Pied crows need to be moved on, not least because there are some vulnerable arrivals in the troop.
0:06:17 > 0:06:21Almost every female is carrying an infant,
0:06:21 > 0:06:26an indication that life is comparatively easy up here.
0:06:30 > 0:06:33With more protection from the elements
0:06:33 > 0:06:38and a little more food, this troop is particularly large
0:06:38 > 0:06:41and can devote plenty of time to their social lives.
0:06:56 > 0:06:59One female even has twins.
0:07:03 > 0:07:06A rare event amongst ring-tailed lemurs
0:07:06 > 0:07:09and a direct result of a good food supply.
0:07:11 > 0:07:18But this valley troop still has to work hard to collect food in this broken landscape.
0:07:20 > 0:07:24Few lemurs are such good rock-climbers.
0:07:45 > 0:07:49There's a real bonanza at this time of year.
0:07:49 > 0:07:55While some gather canopy fruits, the mother of the twins stays lower and gathers fresh leaves.
0:07:59 > 0:08:02The young are born during the fruiting season
0:08:02 > 0:08:04when demands on the mothers are heaviest.
0:08:10 > 0:08:15After such a heavy meal the troop head off in search of their next course...
0:08:15 > 0:08:18a daily dose of dirt.
0:08:29 > 0:08:32Eating soil is thought to help with digestion,
0:08:32 > 0:08:40but it also provides minerals and even helps the lemurs to cope with troublesome gut parasites.
0:08:56 > 0:09:03These troops are becoming even more isolated as farmers push up into the high valleys.
0:09:06 > 0:09:13Now surrounded by rice paddies, these highland lemurs are marooned in their mountaintop islands.
0:09:15 > 0:09:18Here, away from the rest of their kind,
0:09:18 > 0:09:21they have had to adapt in order to survive.
0:09:29 > 0:09:33It's a story that's repeated all across these eastern mountains.
0:09:41 > 0:09:45Each peak is effectively an island,
0:09:45 > 0:09:50and each is home to its own unique collection of animals and plants.
0:10:09 > 0:10:13This mountain range is home to one of these rarities -
0:10:13 > 0:10:17the Andringitra jewelled chameleon.
0:10:23 > 0:10:27Swollen with eggs, this female is on a mission.
0:10:30 > 0:10:34As the rainy season approaches, she begins to dig.
0:10:37 > 0:10:41The only safe place for her clutch is deep underground.
0:10:45 > 0:10:49But her first attempt ends in disaster.
0:10:49 > 0:10:53Unearthing an ants' nest is not a good start.
0:10:55 > 0:10:59She moves on and tries again.
0:11:01 > 0:11:04She needs to find just the right spot.
0:11:04 > 0:11:09Her eggs will remain hidden here for several months.
0:11:11 > 0:11:15It takes her a whole day to excavate the nest.
0:11:17 > 0:11:23Finally she reverses in and lays around a dozen eggs.
0:11:36 > 0:11:40It becomes a race against time to get the eggs under cover.
0:11:46 > 0:11:48She carefully hides her tracks.
0:11:59 > 0:12:03And then she abandons her eggs to their fate.
0:12:16 > 0:12:22Madagascar's mountainous spine is the reason the island's eastern side is so wet.
0:12:24 > 0:12:28It blocks the tropical winds blowing in from the Indian Ocean.
0:12:31 > 0:12:34As the warm, moisture-ladened air hits this barrier
0:12:34 > 0:12:40rain condenses from the clouds and drenches these slopes.
0:12:40 > 0:12:43Over five metres can fall here in a year.
0:12:46 > 0:12:51Rain-swollen torrents pour over giant steps towards the ocean.
0:13:02 > 0:13:06They descend into a richer, greener, more enclosed world.
0:13:17 > 0:13:22The mist-shrouded Marojejy mountains lie in the north-east of the island.
0:13:30 > 0:13:34These cloud forests are a rich, many-layered world
0:13:34 > 0:13:38that offers huge opportunities for life to flourish.
0:13:54 > 0:13:59One bird dominates the dark tangle of the under-storey.
0:14:00 > 0:14:04It's another of Madagascar's many oddities.
0:14:06 > 0:14:08The Helmet Vanga.
0:14:10 > 0:14:15And these wet eastern forests are its only home.
0:14:29 > 0:14:35Why the Helmet Vanga possesses such a vivid blue bill is a mystery.
0:14:35 > 0:14:38But it's certainly a lethal weapon.
0:14:41 > 0:14:46Vangas are ambush hunters, pouncing on ground-living millipedes
0:14:46 > 0:14:49or snatching cicadas and lizards from tree trunks.
0:14:52 > 0:14:59Around 20 species of vanga live on the island, all descended from a single ancestral species
0:14:59 > 0:15:03that became isolated here millions of years ago.
0:15:11 > 0:15:16There's a much more ghostly presence in these tangled forests, too.
0:15:19 > 0:15:25The high canopy is home to one of the world's rarest primates.
0:15:25 > 0:15:30There may only be 200 silky sifakas in existence.
0:15:34 > 0:15:37Extremely sensitive to disturbance,
0:15:37 > 0:15:43these large lemurs have retreated to the region's most inaccessible valleys.
0:15:46 > 0:15:50Leaves and flowers make up the bulk of their diet,
0:15:50 > 0:15:52but such food is difficult to digest
0:15:52 > 0:15:56and they take long rests after each meal.
0:15:59 > 0:16:05However, these essential halts do give them time to indulge their gentle, playful natures.
0:16:14 > 0:16:19The whole family gets drawn into the games.
0:16:23 > 0:16:28Even the older members, distinguished by their paler faces.
0:16:33 > 0:16:37As with most lemurs, the female sifakas are only sexually receptive
0:16:37 > 0:16:40for just one or two days each year,
0:16:40 > 0:16:44so it's crucial for the males to keep a very close check on them.
0:16:45 > 0:16:48The females leave scent-marks on the tree trunks.
0:16:54 > 0:16:59And the dominant males are quick to move in and check the subtle messages.
0:17:01 > 0:17:07They can't afford to miss the one opportunity in the year to father a baby.
0:17:16 > 0:17:21The name lemur means "spirits of the dead"
0:17:21 > 0:17:25and with only a few hundred of these brilliant white sifakas left,
0:17:25 > 0:17:28the name here could be only too prophetic.
0:17:39 > 0:17:44Lower down the mountains, cloud forest gives way to warmer, wetter rainforests.
0:17:54 > 0:17:58Great clumps of bamboo thrive in the tropical heat and damp.
0:18:01 > 0:18:07The tangle of bowed and broken poles creates a natural climbing frame,
0:18:07 > 0:18:12a playground for one of Madagascar's most specialised group of animals.
0:18:15 > 0:18:17Bamboo lemurs are Madagascar's pandas,
0:18:17 > 0:18:22depending almost entirely on this over-grown grass for food.
0:18:29 > 0:18:35Bamboo is tough and woody, hard to chew let alone digest.
0:18:37 > 0:18:43But hardest of all, the leaves of some species are packed full of cyanide.
0:18:43 > 0:18:51Yet three species of bamboo lemur live here eating these plants day in, day out.
0:18:51 > 0:18:56Two of them favour parts of the plant low in poison.
0:18:56 > 0:18:59But the third, the golden bamboo lemur,
0:18:59 > 0:19:01is the real specialist.
0:19:01 > 0:19:06It eats the tips of new leaves that are loaded with cyanide.
0:19:07 > 0:19:10It's not known how they cope with the poison
0:19:10 > 0:19:15but they can tolerate up to 12 times a normally lethal dose.
0:19:20 > 0:19:23Only through these subtle differences in diet
0:19:23 > 0:19:28can all three species share the same small patch of rainforest.
0:19:30 > 0:19:36Bamboo thrives here because this part of Madagascar is very wet throughout the year.
0:19:36 > 0:19:43And these lower eastern slopes are exposed to the full fury of the cyclone season.
0:19:47 > 0:19:54For a few months each year these powerful tropical storms sweep straight in from the Indian Ocean.
0:19:56 > 0:20:00Lasting for days, they create paths of destruction across the island
0:20:00 > 0:20:04and pour huge amounts of water onto these forests.
0:20:34 > 0:20:40But for the bamboo lemurs, these dark clouds have a silver lining.
0:20:40 > 0:20:47In their wake, something peculiar starts springing up all over the forest floor.
0:20:47 > 0:20:50It's what the lemurs have been waiting for all year -
0:20:50 > 0:20:53bamboo shoots.
0:20:55 > 0:20:59The greater bamboo lemurs, in particular, find these spikes irresistible.
0:21:11 > 0:21:15These new shoots are particularly rich in sugary sap.
0:21:29 > 0:21:34It might take half an hour or more to consume a single shoot.
0:21:38 > 0:21:44These bamboo-loving primates are one of the most highly specialized animals
0:21:44 > 0:21:48to have evolved during Madagascar's long isolation.
0:21:48 > 0:21:53But this has left them vulnerable as their forest home disappears.
0:21:55 > 0:22:01As few as 1,000 of them now live in these dappled bamboo thickets.
0:22:09 > 0:22:13The dense canopy means little light reaches the forest floor.
0:22:13 > 0:22:17To survive in this shadowy world, animals need to blend in.
0:22:28 > 0:22:36At just three centimetres long, this brown leaf chameleon is one of the smallest of its family.
0:22:38 > 0:22:42Its long, flattened body gives it excellent camouflage
0:22:42 > 0:22:46as it hunts among the debris of the forest floor.
0:22:51 > 0:22:56Today, it's also getting some help from upon high.
0:23:05 > 0:23:12This mess is being created by the largest of Madagascar's 80 odd lemurs...
0:23:12 > 0:23:13the indri.
0:23:13 > 0:23:16An unlikely ally for the tiny chameleon.
0:23:18 > 0:23:21The fallen fruit is the perfect bait,
0:23:21 > 0:23:24attracting all sorts of insects, including swarms of fruit flies.
0:23:27 > 0:23:32But this tiny predator has its sights set on something a little larger.
0:23:33 > 0:23:36A cockroach.
0:24:00 > 0:24:05As night falls, the forest floor becomes a different world,
0:24:05 > 0:24:10where smell and sound and touch are the primary guides.
0:24:21 > 0:24:28A family of striped tenrecs starts truffling through the dead leaves.
0:24:28 > 0:24:33They may look like hedgehogs, but tenrecs are unique to Madagascar
0:24:33 > 0:24:38and these striped tenrecs are only found here in these eastern rainforests.
0:24:46 > 0:24:53One of the youngsters has been distracted by the discovery of a particularly juicy worm.
0:24:53 > 0:24:56A tenrec's teeth are small but needle-sharp
0:24:56 > 0:25:00and well suited to dealing with this soft slippery food.
0:25:03 > 0:25:09By the time it's subdued its struggling prey, the rest of the family has moved on.
0:25:13 > 0:25:19This is not a good place to be out on your own in the dark.
0:25:21 > 0:25:25It needs to get back to its family,
0:25:25 > 0:25:28but how to find them in the tangled undergrowth?
0:25:28 > 0:25:31They have a unique solution -
0:25:31 > 0:25:33specialised quills on their backs.
0:25:34 > 0:25:37HIGH-PITCHED GRATING
0:25:44 > 0:25:47As these quills rub together,
0:25:47 > 0:25:50they create a high-pitched noise that cuts through the din of the forest.
0:25:50 > 0:25:56It acts like a homing beacon, guiding wayward offspring back into the fold.
0:26:00 > 0:26:05These are the only mammals in the world to communicate in this way.
0:26:11 > 0:26:15Eastwards again towards the coastal lowlands.
0:26:17 > 0:26:19VARIOUS BIRDS CALL
0:26:21 > 0:26:27All that stands in the way are the last cliffs and ravines of the escarpments.
0:26:54 > 0:26:59As the gradient slackens, the rivers slow and spread.
0:27:05 > 0:27:09Down here the forests are even more luxuriant.
0:27:18 > 0:27:23It's so wet that some tree frogs don't need to lay their eggs in water.
0:27:28 > 0:27:35Instead, they stick them to the underside of leaves, well out of reach of hungry fish.
0:27:35 > 0:27:40In less than a week, they've already developed into tadpoles.
0:27:40 > 0:27:43They mature very quickly...
0:27:46 > 0:27:49..but not quite fast enough in this case.
0:27:57 > 0:28:04The most unlikely of predators has stumbled on these clumps of spawn.
0:28:07 > 0:28:12The protective jelly merely slows down the wasp's smash and grab tactics.
0:28:29 > 0:28:32The wasps return again, and again,
0:28:32 > 0:28:38chewing up tadpoles before taking them back to their own nest.
0:28:50 > 0:28:54And yet the tadpoles aren't entirely helpless.
0:28:57 > 0:29:01By the time they are only five days old they are already
0:29:01 > 0:29:05able to react to the vibrations created by the hunting wasps.
0:29:14 > 0:29:17They hatch prematurely when stressed like this
0:29:17 > 0:29:19and as the jelly liquefies,
0:29:19 > 0:29:23the tadpoles dribble down to the leaf-tip and into the water below.
0:29:26 > 0:29:29They may be under-developed, but they can swim well enough
0:29:29 > 0:29:36to give themselves at least a fighting chance away from the jaws of the wasps circling above.
0:29:43 > 0:29:48These lowland forests are full of sinister and unlikely predators.
0:29:53 > 0:29:57Some plants have become meat-eaters.
0:29:59 > 0:30:05The shores of Lac Ampitabe are thick with pitcher plants.
0:30:17 > 0:30:20Their closest relatives are found in Indonesia,
0:30:20 > 0:30:25a place last connected to Madagascar 80 million years ago.
0:30:32 > 0:30:35The liquid-filled cups are modified leaves.
0:30:36 > 0:30:41Insects are attracted by the plant's bright patterns and sweet nectar.
0:30:47 > 0:30:50But it's a fatal attraction.
0:30:52 > 0:30:55The rim of the pitchers is very slippery.
0:31:06 > 0:31:11And the sap appears to have a narcotic effect.
0:31:11 > 0:31:15Once trapped inside, there's no escape.
0:31:18 > 0:31:25Prey is slowly dissolved in the soup of enzymes secreted by the plant.
0:31:27 > 0:31:33On this island of specialists, some creatures have even made this unwelcome place home.
0:31:35 > 0:31:38Ants live in and around the pitchers,
0:31:38 > 0:31:40collecting nectar from the rim.
0:31:42 > 0:31:49Day geckos also sip at the sweet liquid and hunt the insects attracted to the plants.
0:31:51 > 0:31:55The ridged soles of their feet make them super-sticky,
0:31:55 > 0:31:57able to grip on just about any surface.
0:32:01 > 0:32:05But there are still dangers around these pitchers.
0:32:07 > 0:32:11Striped snakes love this tangle of vegetation...
0:32:12 > 0:32:15..and eating geckos.
0:32:19 > 0:32:24At the first hint of danger, the geckos retreat to the nearest cover.
0:32:28 > 0:32:33An old dried-up pitcher is an excellent refuge.
0:32:57 > 0:33:03In these forests staying safe is often best done by keeping a low profile.
0:33:04 > 0:33:07But Paradise flycatchers are hard to miss.
0:33:07 > 0:33:10CHICKS CHIRP
0:33:16 > 0:33:20And with their nest just a metre off the ground,
0:33:20 > 0:33:24the chicks are vulnerable to snakes and other birds.
0:33:36 > 0:33:40Flycatchers, like many birds, have a trick that reduces
0:33:40 > 0:33:43the chance of their nest being discovered.
0:33:49 > 0:33:53The chicks enclose their waste in white faecal sacs.
0:33:55 > 0:33:58Just dumped over the side of the nest,
0:33:58 > 0:34:04these would attract a lot of unwelcome attention, so the adults collect and dispose of them.
0:34:23 > 0:34:28Others living in this forest don't seem to mind being the centre of attention.
0:34:35 > 0:34:40This big, noisy bird is Madagascar's very own cuckoo.
0:34:41 > 0:34:43CUCKOO CALLS
0:34:45 > 0:34:50All these calls are directed at its tiny foster parents.
0:34:52 > 0:34:55Having disposed of their young long ago,
0:34:55 > 0:35:00this super-sized impostor is monopolizing their attention.
0:35:02 > 0:35:06They seem unable to resist its incessant demands.
0:35:07 > 0:35:10But now that the cuckoo is nearly full grown,
0:35:10 > 0:35:13their exhausting ordeal will soon be over.
0:35:25 > 0:35:29These lowland forests also contain a curious throw-back -
0:35:29 > 0:35:32a plant that reveals a link
0:35:32 > 0:35:36to a time when Madagascar was still connected to mainland Africa.
0:35:38 > 0:35:42The Traveller's Tree is only found in Madagascar, but its closest
0:35:42 > 0:35:47relatives are the bird of paradise flowers growing in Southern Africa.
0:35:53 > 0:35:54Over on the mainland,
0:35:54 > 0:35:57those plants are pollinated by nectar-feeding birds.
0:36:00 > 0:36:04But in Madagascar, the Traveller's tree has evolved
0:36:04 > 0:36:06to attract another pollinator.
0:36:08 > 0:36:12Not a bird, but something altogether stranger.
0:36:14 > 0:36:19The large flowers produce huge amounts of sugary nectar
0:36:19 > 0:36:23and they are tough enough to withstand rough handling.
0:36:27 > 0:36:32And they need to be when aye-ayes come calling.
0:36:41 > 0:36:46It may not look much like one, but the aye-aye is a lemur.
0:36:51 > 0:36:54As it feeds, its snout becomes coated with pollen,
0:36:54 > 0:36:57which it then carries to other Traveller's Trees
0:36:57 > 0:37:00as it makes its nightly rounds of the forest.
0:37:07 > 0:37:10For the aye-aye, nectar is just a passing fancy.
0:37:10 > 0:37:15What's really shaped their extraordinary appearance
0:37:15 > 0:37:16is a love of beetle grubs.
0:37:19 > 0:37:23Its large ears, gnawing teeth and long, thin fingers
0:37:23 > 0:37:25are all beautifully adapted to detect
0:37:25 > 0:37:30and winkle out juicy larvae from under the bark of rainforest trees.
0:37:38 > 0:37:44In a few places, the rainforest extends right down to the ocean.
0:37:52 > 0:37:56The largest stretch left in Madagascar grows
0:37:56 > 0:38:00on the remote Masoala peninsula in the north of the island.
0:38:02 > 0:38:05Here, there are hundreds of square miles of pristine jungle.
0:38:09 > 0:38:14Growing right next to the ocean brings its own particular challenges.
0:38:14 > 0:38:18The forest trees must cope with shifting sandy soils
0:38:18 > 0:38:21and being regularly showered with salty spray.
0:38:25 > 0:38:29Nonetheless, the forest is full of wildlife.
0:38:49 > 0:38:56Standing water can be hard to find here because the sandy soil drains so quickly.
0:38:56 > 0:39:00That makes life very difficult for frogs looking for somewhere to lay their eggs.
0:39:00 > 0:39:05But storm-damaged bamboo stalks provide the solution.
0:39:12 > 0:39:15These rain-filled reservoirs are communal meeting places
0:39:15 > 0:39:19for Madagascar's unique golden bamboo frogs.
0:39:21 > 0:39:25In the breeding season, this community spirit breaks down
0:39:25 > 0:39:30as individual males compete for the water-filled stems
0:39:30 > 0:39:33and start calling to attract mates.
0:39:41 > 0:39:47In response, females are drawn to the males and their bamboo pools.
0:39:50 > 0:39:56This female is a late arrival on the scene and she needs to be very wary.
0:39:56 > 0:40:01Another female has been here, and there's already a tadpole in residence.
0:40:02 > 0:40:06There's very little food in these pools, and the last thing she wants
0:40:06 > 0:40:10is her valuable egg to end up feeding another female's tadpole.
0:40:12 > 0:40:17So she rejects the males' advances and moves on.
0:40:20 > 0:40:27Eventually, she finds an unoccupied pool where she can be sure of laying the first egg.
0:40:27 > 0:40:31And she has a way of getting around the shortage of food, too.
0:40:33 > 0:40:37Once her egg has hatched, she will return repeatedly
0:40:37 > 0:40:41to lay an infertile egg on which her tadpole will feed.
0:40:55 > 0:41:00This is a highly competitive world.
0:41:00 > 0:41:07Predatory birds like couas and Madagascar coucals have leaf geckos on their menu.
0:41:07 > 0:41:09But first they have to find them.
0:41:09 > 0:41:16These geckos are able to stay absolutely motionless.
0:41:18 > 0:41:21Some have evolved ragged fringes around their bodies to help
0:41:21 > 0:41:24break up their tell-tale outline.
0:41:29 > 0:41:31The largest, up to 30 centimetres long,
0:41:31 > 0:41:34hide on favourite tree-trunks that match
0:41:34 > 0:41:37their particular skin colouration.
0:41:44 > 0:41:48But as night falls, they are transformed.
0:41:48 > 0:41:51The hunted become hunters.
0:41:57 > 0:42:01Now it's not about camouflage, but stealth and surprise.
0:42:07 > 0:42:10Their huge eyes help them track prey in the darkness.
0:42:14 > 0:42:19Large mouths packed with sharp teeth help them tackle difficult prey,
0:42:19 > 0:42:23but not necessarily to deal with smaller pests.
0:42:38 > 0:42:43Their sight is 350 times more sensitive than the human eye.
0:42:43 > 0:42:48These geckos can see colour even in the dimmest moonlight.
0:43:17 > 0:43:22They have no eyelids, so licking is the only way to keep their eyes clean.
0:43:56 > 0:44:00This caterpillar apparently doesn't taste good.
0:44:05 > 0:44:11But a bad taste doesn't stop the gecko getting in a little retaliation.
0:44:27 > 0:44:32The richness of these coastal forests is unrivalled on the island.
0:44:35 > 0:44:39Although the Masoala rainforest covers only 2% of Madagascar's
0:44:39 > 0:44:45surface, over half of all the species found on the island are thought to live here.
0:44:45 > 0:44:50The tallest trees of the peninsula's most remote valleys are home
0:44:50 > 0:44:53to one of its most spectacular inhabitants.
0:44:53 > 0:44:56Red-ruffed lemurs are big and noisy.
0:45:00 > 0:45:04This troupe has hit the jackpot - two trees, a fig and a harami,
0:45:04 > 0:45:09practically next door to each other and both loaded with ripe fruit.
0:45:11 > 0:45:16With so few seed-eating birds on the island, the trees rely on lemurs
0:45:16 > 0:45:20like the red-ruffs to disperse their seeds through the forest.
0:45:25 > 0:45:31After gorging all morning, the clan settles down nearby to sleep off their lunch.
0:45:39 > 0:45:44But while most doze, one lemur stays behind.
0:45:44 > 0:45:48It's his job to guard the trees from fruit-robbers.
0:45:51 > 0:45:57And in such a rich forest a fruiting tree quickly becomes a magnet for other interested parties.
0:46:03 > 0:46:06Madagascar green pigeons are quickly seen off.
0:46:08 > 0:46:14A vasa parrot has slipped in under the lemur's guard.
0:46:14 > 0:46:18But it makes little impact on the supply of figs.
0:46:27 > 0:46:30Others need to be watched more carefully.
0:46:37 > 0:46:43A gang of white-fronted brown lemurs have spotted the fruiting trees and want a share.
0:46:52 > 0:46:58The males have striking white caps and they lead the raid.
0:47:19 > 0:47:23It takes the red-ruffed guardian a while to catch on to what's happening.
0:47:34 > 0:47:38The brown lemurs are quick and agile.
0:47:43 > 0:47:51And with ten of them and one of him, it's not that easy to get control of the situation.
0:48:14 > 0:48:18By the time he's finally seen them off, the rest of the clan
0:48:18 > 0:48:21are on their way back to feed in the harami tree.
0:48:40 > 0:48:46With food just an arm's length away, these particular lemurs appear to be living the good life...
0:48:46 > 0:48:48at least for the moment.
0:48:50 > 0:48:55But red-ruffed lemurs are only found in this one stretch of coastal rainforest.
0:49:06 > 0:49:09Their extreme specialisation,
0:49:09 > 0:49:11developed over millions of years,
0:49:11 > 0:49:15enables them to exploit every opportunity that this forest offers.
0:49:20 > 0:49:24But it also comes at a heavy cost.
0:49:24 > 0:49:27It leaves them vulnerable if that opportunity disappears.
0:49:29 > 0:49:34The few miles that separate Madagascar's highest mountains from
0:49:34 > 0:49:42these tropical shores are crowded with animals and plants trapped in their own very narrow world.
0:49:44 > 0:49:51And with these eastern forests rapidly disappearing, these unique worlds
0:49:51 > 0:49:56and their extraordinary inhabitants may soon be lost forever.
0:50:09 > 0:50:14Working in Madagascar's most isolated corners is a real challenge and
0:50:14 > 0:50:20this trip to film red-ruffed lemurs proved to be one of the hardest.
0:50:20 > 0:50:23For this shoot, cameraman John Brown and producer Ian Gray
0:50:23 > 0:50:29have been joined by expert tree-climbers Tim and Pam Fogg.
0:50:31 > 0:50:36They will be responsible for getting John into the forest canopy where these rare lemurs live.
0:50:41 > 0:50:47The easiest way onto the Masoala peninsula, a four-hour ride in a fast boat.
0:50:50 > 0:50:57The crew rendezvous with their local guides at a little-used research station on this isolated coast.
0:51:01 > 0:51:06They need to be entirely self-sufficient while working here.
0:51:07 > 0:51:10Home sweet home.
0:51:12 > 0:51:16That's the toilet. Nice.
0:51:16 > 0:51:19Luxurious. Lovely.
0:51:19 > 0:51:23Better than the huts outside.
0:51:23 > 0:51:29Red-ruffed lemurs are endangered and these forested mountains are their last refuge.
0:51:31 > 0:51:38It might seem like looking for a needle in a haystack, but the crew have a cunning plan.
0:51:42 > 0:51:44Uphill all the way.
0:51:44 > 0:51:48Red-ruffed lemurs love to eat fruit, so find a fruiting tree
0:51:48 > 0:51:51and the red-ruffs shouldn't be too far behind.
0:51:53 > 0:51:55This is a cruel hill.
0:51:55 > 0:51:57You just look up and it just goes on.
0:51:57 > 0:52:00On and on. Hundreds of metres.
0:52:00 > 0:52:01It's a brute.
0:52:04 > 0:52:08Then, on the second day of searching, they get a lucky break.
0:52:13 > 0:52:17That tree looks like it's loaded with fruits.
0:52:17 > 0:52:19Can't see any lemurs though.
0:52:19 > 0:52:21- No. It's a lovely tree though. - It is.
0:52:25 > 0:52:28Those are definitely red-ruffs... aren't they?
0:52:28 > 0:52:30Over there somewhere I think.
0:52:30 > 0:52:36This is encouraging. It's only the second day and things are looking distinctly promising.
0:52:39 > 0:52:42We've lucked out, finally. We've found a big fruiting harami tree
0:52:42 > 0:52:47just over the ridge here and there are red ruffs working in these trees.
0:52:47 > 0:52:52And the best thing is there's another tree next door to it which we think we can get the platform into.
0:52:52 > 0:52:54We'll see what tomorrow brings.
0:52:57 > 0:53:00Rain. Lots of it.
0:53:01 > 0:53:05And this is supposed to be the dry season.
0:53:05 > 0:53:10The tropical paradise is suddenly losing some of its glamour.
0:53:12 > 0:53:17Hoping the rain will soon pass, the crew heads off into the forest to
0:53:17 > 0:53:23rig the filming platform so that it's ready when the weather improves.
0:53:23 > 0:53:27But if anything, the rain is getting worse.
0:53:40 > 0:53:45The hardest part is getting a line up into the tree.
0:53:49 > 0:53:54This will be used to pull up a rope,
0:53:54 > 0:53:59and then haul up the filming platform and fix it in place.
0:54:01 > 0:54:0730 metres up, this will put John level with the lemurs as they feed.
0:54:13 > 0:54:16By the end of a very wet day,
0:54:16 > 0:54:21the only camera still working is on a mobile phone.
0:54:21 > 0:54:25It's a bedraggled team that arrives back at camp.
0:54:27 > 0:54:29Oh, dear.
0:54:38 > 0:54:40Everything has been thoroughly soaked.
0:54:40 > 0:54:44The crucial thing now is to try and get the cameras dried out.
0:54:51 > 0:54:54What's really annoying is you kind of know that
0:54:54 > 0:54:58the animals that we've come halfway round the world to film
0:54:58 > 0:55:02are probably doing exactly what we want them to be doing,
0:55:02 > 0:55:04and looking fantastic somewhere up a tree.
0:55:06 > 0:55:09# When it rains five days
0:55:11 > 0:55:14# And the skies turn dark as night... #
0:55:14 > 0:55:17All anyone can do is to be patient
0:55:17 > 0:55:19and hope for a change in the weather.
0:55:19 > 0:55:22# When it rains five days
0:55:23 > 0:55:28# And the skies turn dark as night
0:55:34 > 0:55:36# Then trouble's taking place
0:55:37 > 0:55:40# And you know everything ain't right. #
0:55:40 > 0:55:45After eight long days, there's a small break in the clouds
0:55:45 > 0:55:49so it's quickly back up the hill once again and onto the platform.
0:56:00 > 0:56:05This is day eight of the shoot, and so far I've shot about
0:56:05 > 0:56:11two minutes of film and it looks like there's another storm coming
0:56:11 > 0:56:13in across the bay that I can see.
0:56:13 > 0:56:21As the storm breaks, being up a tree on a metal platform doesn't seem to be a good idea.
0:56:21 > 0:56:24- THUNDER RUMBLES - Time for another hasty retreat.
0:56:26 > 0:56:30So far, I'm not sure we're going to get what we need,
0:56:31 > 0:56:32but we'll just keep trying,
0:56:32 > 0:56:36cos, well, erm, what else can we do?
0:56:36 > 0:56:40Desperate times call for desperate measures.
0:56:40 > 0:56:45The key thing is to get rid of the condensation without melting the lens.
0:56:50 > 0:56:52Day nine.
0:56:52 > 0:56:55It's stopped raining.
0:56:55 > 0:57:01No it hasn't! It's still raining, and it rained all night, and we're all going absolutely stir crazy.
0:57:01 > 0:57:03Doy-ing!
0:57:03 > 0:57:05I see why you married him!
0:57:07 > 0:57:11I think all of us could do with seeing the sun and getting dry underwear on.
0:57:11 > 0:57:13That would make life a lot better.
0:57:16 > 0:57:21Finally, the storm fronts blow through.
0:57:21 > 0:57:26It's time for one last slog back up to the platform.
0:57:26 > 0:57:30So after ten days of trials and tribulations and a lot of rain,
0:57:30 > 0:57:32we've finally got John up in the tree.
0:57:32 > 0:57:35So now all we need now are the red-ruffs to come and do their stuff.
0:57:35 > 0:57:39I can hear them calling already, so hopefully that's a good sign.
0:57:39 > 0:57:42We're having a very strange meteorological phenomenon
0:57:42 > 0:57:47known as blue sky, and the lemurs have been in
0:57:47 > 0:57:53and feeding and sunbathing, and it's been just such a relief.
0:57:56 > 0:58:00So yeah, it's amazing what a difference the weather makes.
0:58:09 > 0:58:13In the next episode, we cross Madagascar's mountains
0:58:13 > 0:58:19into the southwest of the island, a land that is gripped by dryness for most of the year.
0:58:19 > 0:58:21Among these dramatic landscapes
0:58:21 > 0:58:25lives some of the strangest wildlife of all.
0:58:47 > 0:58:50Subtitles by Red Bee Media Ltd
0:58:50 > 0:58:53E-mail subtitling@bbc.co.uk