Episode 2 Lost Land of the Volcano

In the remote jungles of Papua New Guinea, an international team of scientists and filmmakers

has been searching for rare and endangered creatures.

We could find something really, really spectacular inside here.

I guess that's the hope.

Two weeks in and they've made an impressive start.

What an extraordinary looking fish.

-They've found the weird...

-I have no idea what that will become.

-The wonderful.

-Now you can really see how tiny he is like compared to your thumb.

And discovered animals unknown to science.

I'll bet you any money that wasp right there that's walking along that leaf is a new species,

I bet you any money.

They've hunted high and low.

Now, beneath the forest floor, Steve Backshall is pushing deep into a cave,

one of the few places on Earth where no-one has been before.

I've never seen anything like this before in my life.

This is extraordinary!

Just above Australia in the western Pacific

lies Papua New Guinea.

Cloaked in dense rainforest, these valleys are among the most isolated on the planet.

The main base camp is on the slopes of an extinct volcano, Mount Bosavi.

Further east, a smaller team is on the island of New Britain.

They're exploring an underground river cave, mapping it as they go.

This is one of the most remote, inaccessible places on the planet

and there genuinely are dark corners of Papua New Guinea that no human being has ever been to before.

This place is absolutely ripe for exploration.

It's risky.

Just to get in means abseiling 80 metres to the cave entrance.

Oh, it's pretty nippy, isn't it?

Steve Backshall is the expedition climber, caver and naturalist.

Oh, this is unbelievable!

-Look at that.

-What an unbelievable amount of water.

Welcome to Mageni river cave.

He's joined the Anglo-French team who first discovered this cave.

The locals call it Mageni.

They're led by pioneering British caver Dave Nixon, known as Moose.

I remember coming up here

really, really excited, not knowing what was at the top.

Well, it makes you feel so alive.

Their aim is to press further into this uncharted cave

and map passages never seen before by man.

Plus 5.7.

Lucy is bouncing a laser off the walls of the tunnel so we can figure out how big it all is.

That's the whole purpose of surveying, it's just to map out the size of the caverns.

Jean-Paul, this joint is developed on

50 degrees, 230. 50, 230.

What fires them is the hope of finding a new, undiscovered route right through the mountain.

700 miles west in the shadow of Mount Bosavi lies the base camp.

A cluster of makeshift huts is home to the wildlife filmmakers, the expedition medic,

expert trackers,

cooks...

and, at its heart, the scientists.

Leading them is Dr George McGavin.

I'm heading up a team of scientists, experts in their own field.

Our aim is to document what animals live in and around this giant, extinct volcano,

and also to search for any new species, and there must be hundreds.

The cooks are preparing the dinner,

when their fishing nets land something bigger

than they'd bargained for.

George is on hand to help.

It's a crocodile, I think.

Croc expert Paul O'Dowd has to work fast but carefully.

It's really essential that we secure the front end,

and the jaws have to be tied shut otherwise

they could take somebody's hand off.

But she's really growling,

you can feel that "grrrr" in her throat.

She's not a happy croc at all.

Almost unnoticed in the net, there's a venomous catfish.

There's a big fish here

and the spine is loaded with very nasty toxins,

and if that jabs into Paul's hand or my hand, not nice,

you'd be a very sick person.

Actually, George, maybe with your free hand

could you just sort of make sure that this...?

-That's the way.

-It's not everyday that you have to restrain

a large freshwater crocodile

while holding a toxic spine of a catfish in your other hand.

Out of the net, the crocodile is now free to go.

Fantastic, happy ending.

She's off, she's safe.

Well done, mate.

It's all in a day's work.

But George's main job is running the jungle lab.

This is an absolute monster.

His team has already discovered 17 new species

and catalogued hundreds of other animals.

-What have you got there, Jack?

-The latest creature has just been found

on a tree right next to the lab.

It's quite clearly a group of three caterpillars

on that vine of some sort.

I have no idea what that will become.

It looks almost as if it's a snake.

You know, it's quite disturbing if you're a bird I suppose.

As an extra defence, two of them will thrash around like that.

Well, what I think we should do is we should put them in a cage

and just observe them, but it could be weeks until they actually pupate,

which is the only way of finding out what they'll become.

Some animals are showy,

others hide away hoping they won't be seen.

This one's cover has just been blown by wildlife cameraman Gordon Buchanan.

Oh, do you know what that is?

It's a beautiful fruit dove.

That's what it's called, that's not my name for it.

I love all the names of...

especially birds in Papua New Guinea.

You've got all these magnificent bird of paradise,

magnificent rifle bird, the superb fruit dove,

the beautiful fruit dove, they're all very descriptive.

Unbelievably camouflaged sitting there. Such a good find.

It's one of the jungle's more unassuming characters,

but Gordon has his sights set on a far more flamboyant bird.

Personally, I want to find Birds of Paradise.

They are the most iconic bird family on the planet.

They have fascinated every ornithologist, every naturalist

since they were first discovered 400 years ago. I'm no different.

Gordon's mission is to record

one of the most extraordinary rituals in nature,

the mating display of the Bird of Paradise.

Underground, Steve and the caving team

are battling against the white water river.

Steve is the team's naturalist.

Even in a cave, some creatures still survive.

These cave crickets are real specialists

at this kind of environment.

They have tiny little eyes but really almost all of their senses

are in these gigantic antenna.

Look at that, I mean that is probably six times the length of the body.

They're tactile. They tap around a bit in front of the cave

just feeling its way, and also pick up chemical signals.

So it works like a nose, like eyes

and also a bit like a blind man's white stick as well.

I think this one here is a female.

Possibly the least pretty-looking girl in the world.

In total darkness, looks are irrelevant.

Above ground, appearances can be everything.

Bird expert Jack Dumbacher's found a King Bird of Paradise.

I would like to take a blood sample.

So there's a small vein that runs right under the arm here,

we can get the DNA from the blood.

We can use that for genetic studies,

and we can also use it to test whether or not the birds

are carrying malaria or other blood diseases.

Keeping a record of all the animals is expedition photographer Ulla Lohmann.

I've never seen colours like that.

I mean me being a photographer

I love colours and especially when the light is just breaking

into it's feathers, it's just magnificent.

All these colours are to impress the female and their mating display.

They flash all these colours, they have a special dance that they do

and the female is very drab

so she doesn't have any of these specialised colours,

just the male has these.

Completing the look are elaborate tail wires

that play a big part in his courtship display.

It's an important find, proof that Birds of Paradise

live in this patch of forest.

HIGH PITCHED SQUEAKING

-What have you got, Jack?

-Good to see you, Gordon.

Caught up in that net.

Let me just get my hand down in there so that he can't get away.

Oh, a king! Oh, you beauty.

Oh, my goodness me.

They are quite incredible.

All the Birds of Paradise are almost beyond belief.

Jack releases it just where it was found.

Well, it looks like he's happiest on a vertical perch.

Birds of Paradise look stunning,

but even more impressive is their courtship dance.

Catching this on camera will draw Gordon deep into the jungle.

These forests are now under threat.

There's big money to be made from tropical timber.

This forest giant has been growing here for between 100 and 150 years.

The value of this tree when it's cut down to the landowner,

the man who owns this tree, is only about £8.

When it's prepared and shipped out as timber in the UK

it will fetch £1,000 or more.

Somebody is making a great deal of cash,

and it's not the people who own this tree.

Papua New Guinea's forests are peppered with hundreds of remote tribes.

It's those tribes and not the government

who own the land and the trees.

Tribal elders have a difficult decision to make...

Keep their forests,

or sell the trees to the loggers.

If we keep forests like this intact,

we will reduce our chances

of suffering the worst effects

of global climate change and we'll save between 60 and 80%

of all the world's species.

For me, it's a no-brainer.

In the cave, progress is slow and exhausting.

They need to stop and refuel.

The French have brought cheese,

and the Brits,

baked beans.

Oh, please tell me you're not eating cold baked beans?

-What's the matter with you, man?

-Oh, you're all wrong!

I'll have some of that, that's mine.

No, the cheese, cheese is good.

Oh, no, that absolutely turns my stomach.

-Smell that.

-This is actually pretty good for us.

I mean we've really just been having a chocolate bar for lunch most days.

To actually stop and have cheese and crackers, it's luxury!

YORKSHIRE ACCENT: Eee, you don't know you're born, lad!

From base camp, two boats head upstream.

Gordon's first stop on his search for Birds of Paradise

is a remote village where the feathers are used for costumes.

Also on their way are George and expedition medic Jane Stevenson.

The boats' engines disturb a colony of bats roosting in the treetops.

This is quite spectacular.

These are flying foxes, they're the largest bats on the planet.

They are just amazing, look at the size of them.

They must have a wingspan of about that.

They eat, I think it's exclusively fruit.

When they eat the fruit they pass through the seeds,

so they are pretty much the species

that is responsible for keeping this forest living and growing.

Oh, wow!

Fogomaiyu village is dominated by the extinct volcano Mount Bosavi.

Contact with outsiders is rare.

Yeah, it's an unbelievable welcome,

you're sort of quite overwhelmed about somewhere like this

and so many people just turn out

with just big smiles on their face.

Is he a big man in the village?

-This man?

-He's the chief.

-Oh, I see.

His name is Chief Ayambo.

These villagers know more than anyone

about Birds of Paradise and where they display.

Thank you, thank you.

Hello. It's Gordon, pleased to meet you.

These feathers are from Birds of Paradise?

Cassowary, OK.

It's a very poor village of just 500 people.

Medicines are in short supply

and there's been a severe outbreak of malaria.

Here in this particular village one of the biggest problems is access.

They can't get out to hospitals,

they can't get out to clinics,

they can't get medicines brought in,

and everything is so expensive for them that health

has actually had to take a back seat really, to just pure survival.

While Jane sets up a makeshift clinic,

George meets the village elders

to find out what the future holds for them and their forest.

First of all, I want to thank you very much

for us being able to be here in this fantastic forest land of yours.

It has been a great honour. You own a huge area of valuable land.

You could sell your land, you could sell your trees.

What do you want to happen, what's the way forward?

Well, you know, you're sort of stuck because you want certain things,

you want to pay for education and healthcare and soap and things,

but you don't have the means of earning the cash.

How many children die here?

At Jane's clinic, a concerned mother has brought in her feverish child.

We need to be sponging this baby down.

I'm going to test the baby for malaria but it probably is malaria.

It's one of the biggest killers in the tropics.

Out here, mosquito nets are virtually non-existent.

Can you see there's two lines there?

Jane's test confirms her worst fears.

He is particularly vulnerable now. He has a raging fever

and he has the worst type of malaria strain.

This is today's dose,

as soon as possible.

Although the baby is getting quite upset with this

it is absolutely the best thing.

This will potentially save his life

and without this there is a very high chance that he will die.

A mile into the mountain, rescue from outside is next to impossible.

The water here is very fast-flowing and deep,

that's why we're wearing lifejackets,

because really if you're spending a lot of time in the water

try not to get too cold, and really just battling against the flow.

Moose has put in these lines so you could traverse across safely.

Whoa, it's pretty faster here, Moose.

-Don't want to get swept away there, do you?

-Watch your feet.

Oh, it's like the North Sea. Freezing.

Forcing themselves against the flow, the team press on into the darkness.

Here he is. This is a dwarf kingfisher.

You can see just how small he is.

George is back at work with the other scientists.

Look at that. It's really fast.

Their work is vital if they are to prove this jungle is worth saving.

Alanna Maltby is the bat expert.

She's made another important find.

This is the second potential new species of bat.

-Amazing.

-Yeah, really is amazing.

It's really unusual to find new mammals and new bats,

and to have two potential new species in the course of a couple of weeks,

that's just that's like nothing I've ever come across.

The frog man has been kept busy too.

You could spend the whole day trying to catch one of these things.

But this is yet another frog which Alan Allison has never seen before.

It's an interesting little guy

because I'm almost certain that it's a new species.

This is exactly why I'm here.

We're seeing animals in a 100 years time might not even be here.

The scientists will report their findings

to the government of Papua New Guinea

to lend support in protecting Mount Bosavi's weird and wonderful wildlife.

This is amazing, this is a really strange world.

Here is a beetle larva.

Over there, we have a tiny bat.

So here is an animal with a backbone that is a fraction the size of this.

Alanna, can I just compare the size of that bat

to the size of this insect?

Which one do you think is more beautiful, George?

I have to confess, Alanna,

on this occasion the bat does win it hands down.

Even I couldn't really love this thing.

In Mageni, the only respite from the deafening river

is to enter one of its many side caverns.

Wow, this is nothing like any other cave we've seen so far at Mageni.

It's quiet, relatively dry.

We can talk to each other without shouting.

Yeah, it's incredible, isn't it?

Looks at these stals, they're fantastic.

Check this out here, Steve.

See this formation, you've got a column that's formed

where a stalactite has met a stalagmite.

This is deposited on a mud floor,

but can you see how it's all fractured and broken there?

That's almost certainly as a result of earth movement, earthquakes.

What do you think it would be like down here if...

It would be terrifying, really would be terrifying.

It's been a long day of caving and, two miles into the mountain,

they have to find somewhere to sleep.

It's dusk in the village.

Tomorrow, Gordon will set off in search of Birds of Paradise.

But tonight, the village elders have allowed him

to see their head dresses.

So this is from the Ragi Bird of Paradise.

You are correct, some... Raggianna.

Yeah, see I know what

I'm talking about!

OK. It's like having a personal dresser.

-So do they use these headdresses for ceremonies?

-For ceremonies, yes.

Um, this is quite unexpected.

A lot of early collections of Birds of Paradise

and other bird species that are found in Papua New Guinea

came from headdresses which were sort of taken by explorers

and brought back to the west,

and in those early days when they saw feathers like those,

ornithologists just thought it was fakery,

that it couldn't be a bird that had such spectacular feathers.

I've made myself a little pit here

and my sleeping bag ready to go.

Tackle bag and half a carry mat, what more could a man ask for?

The cavers have found a place for the night, but they're not alone.

That is really weird.

This is a freshwater crab from the outside

and I would guess that it's probably been swept in here

right from where the water's gathered for this cave.

What's incredible though, to me,

is if you look at it close up,

its' absolutely covered in parasites.

Rather grotesque white blobs

which are kind of moving all over it, I mean look at those.

I've never seen anything like this before in my life.

It really lends to the sense

this place has of being just like an alien landscape.

It's enticing to think from here quite how much is unexplored,

that's like what we've seen so far in this area.

It's probably riddled with caves like this

and some of them will never see the light of day, and never be explored.

The team desperately need their rest.

But in a small damp cave under a million tonnes of rock,

sleep may not come easily.

In the village, a tribal dance begins.

THEY CHANT

You've got everything that represents light and life in the forests.

These guys wearing spectacular headdresses, Birds of Paradise,

cockatoos, hornbills, all this sort of lush vegetation

they've adorned themselves with.

Centre stage are the feathers

from one of the largest birds of paradise, the Raggianna.

These are from Raggianna.

Raggianna Bird of Paradise. And if you just look at the...

Better from this angle. They look as if they've been doctored.

They're just very un-feather like but very exquisite

and that's just a small proportion of the feathers that are on this bird.

If you think these costumes are elaborate,

they are nothing compared to the birds themselves.

This is a sort of an imitation of their splendour.

WHISPERS: I've just woken up in the middle of the night.

Well, I think it's the middle of the night, could be any time really.

Bit sort of tossing and turning with weird dreams

about scuttling white cave crabs and things.

I've suddenly picked up a fever,

I've had the shakes, very high temperature,

and a couple of sort of weak panic attacks with it as well.

I feel absolutely awful.

Just typical that it would happen tonight.

Lie back down and try and get a bit more sleep

but just can't wait for the morning and get out, really.

At daybreak, Gordon sets off with trackers from the village

looking for birds of paradise that are displaying.

The one saving grace we have is that Birds of Paradise are very vocal.

We want to see them displaying

which will give us an indication

that they are in this area and they are breeding.

I'm hoping that we can hear those sounds

and zone in on them and find the birds based on their calls.

It's definitely getting rougher.

Pouring down from Mount Bosavi

is a network of rivers that they must cross.

So, how are we going to get across this?

We will use a log to make a bridge.

Put a log across, there's no way to walk round, no?

They swim when they can, but the camera gear must be kept dry.

They've managed to get that over but if you fell in there

with a backpack on, you'd be a goner.

Deep underground, Steve Backshall is going nowhere.

I still have a really heavy fever and it was spiking in the night.

I was actually hallucinating it was that bad.

I just feel like I want everyone else to go out

and just leave me here.

That's not an option though, is it?

Well, it's not really an option,

no, but I feel absolutely desperate.

Tim Fogg is in charge of safety.

It's his job to get Steve out of the cave.

This is a very, very remote place.

We're a long way from home.

We're going to have to help them as much as we can,

but basically he's going to need to get out under his own steam.

Even though the water's warm,

it still gets to you a bit after a while.

Steve is weak and running a high temperature.

Lets go, Steve. Let's go, mate, straight through here.

You all right?

Come on, mate, you're doing great.

Calling from the canopy is a King Bird of Paradise.

Gordon's found a display site.

It's right here, come over.

Fortunately, the King does his courting close to the ground.

Oh, yeah, there he is.

I'm hoping that this is him getting ready for his big display,

just making sure that all his feathers are in order.

Great, now that's just the start of the display

as he jumps from either side of the branch.

These tail wires whack back and forward

and that's attracting the female even more.

Oh... duck down again. Oh, there he is right out in the open.

OK, he's started displaying.

He's brought the little tail

that he does have right up to flat with his back,

and tail wires are kind of dangling about over his head,

and he's sort of jiggling back and forwards.

There must be a female up there.

On, yeah, there we go, there's a female.

Gosh, you wouldn't even think that that was the same species.

It's very easy to relate to this Bird of Paradise behaviour

because it pretty much mimics what a lot of men do

is to show off to attract women.

It's the kind of disco scenario, the best dancer,

the best dressed man sort of gets the best choice of the women, he gets the best women.

Very easy to understand.

Amazing.

Practically every life form

that lives in this rainforest depends on the forest.

You lose the forest, you lose the animals just like that,

it's a very, very simple equation.

You can't have one without the other.

And that's the terrible thing about deforestation.

You're not just losing the trees you're losing this habitat

and everything that depends on it.

In the lab, the scientists are finding yet more evidence

of the richness of this forest.

Satellite images reveal just how rapidly jungle is disappearing.

This is the scariest series of images that I think I've ever seen.

This is pristine rainforest

that has existed in this area for 10,000 years.

16 years ago it looked like that,

virtually untouched.

And the most up-to-date image shows the road for forestry vehicles

which are coming in to extract the wood,

now spreading like veins all over the forest,

and this is only 20 miles from here.

This makes the mission to explore Bosavi's forests

all the more urgent.

I think the thing that's really striking about this

is the incredible diversity,

so every time you turn a corner you see a new insect,

you see a new frog,

you see a new beetle and that's the fun of it.

George has been mesmerized by his mysterious caterpillars.

At last, they're starting to pupate.

There is one of the little caterpillars.

It's hidden away on this folded leaf

and it's also taken a bit of this dry leaf,

and it's used a bit of silk, and it's now just hiding.

Now I'm assuming what it'll do now is to pupate.

But wouldn't it be great to be here when those hatched out

and then we'd at last know what this amazing animal becomes as an adult.

At Mageni, the cavers have reached the surface camp

and Steve's fever is subsiding.

The rest of the team also need time to recover.

I have a kind of a rash on my body, just like burning my whole body.

It's not very nice.

Steve's gaining strength and keen to get back to the job.

Before they go into the cave,

they're adding their new data to the computer.

In the 21st century,

it's rare to be able to explore and chart a whole new river system.

Well, this crunches all the numbers that we get when we go surveying,

and very cleverly creates a 3D model of the cave.

And it's by no means fully explored

and there's various leads on here,

these little dead ends or look like dead ends,

these are passages that we didn't explore fully

and are waiting to be surveyed.

And it's just a matter of getting there and doing it and that's what burns a hole in my head.

The lure of the cave is strong.

Fired up again, the team drop back down the cliff side.

Truly, this is the land of the unexpected.

On the eastern slopes of Mount Bosavi,

Gordon is still tracking birds

when he discovers a river erupting from deep underground.

This is a place with lots of strange things

and this is another one of them.

This is the start of a river, a river that...

well, actually, no, it's not the start because this river is flowing underground.

It is just very peculiar.

All of this water getting pushed,

a huge quantity of water that's flowing down from Bosavi underground

into a big channel that wells up here.

And I would say that this is the best example of the power of water

and unseen goings on, things that are going on way beneath our feet.

And then, at last, high in the trees above Gordon,

the sound he's been hoping for.

It is a Raggianna Bird Of Paradise calling.

This time of day it will still be displaying.

It's great to know that they're in here,

and it's definitely one I want to try and film

cos they are gobsmackingly beautiful.

The Raggianna displays only in the treetops.

Gordon shoots a line 20 metres up a nearby tree.

He'll have to haul himself and all his kit up into the canopy.

Few people have ever seen a Bird Of Paradise, let alone, you know,

sat up in a treetop with them so there is a real sense of privilege.

Gordon must move quietly, so he doesn't drive the birds away.

Oh, bats!

Lots of them.

Steve and the cavers are back in Mageni,

retracing their steps to where their exploration left off.

Oh, yeah!

And it's not long before their effort pay off.

-Just found a lead.

-What, a new passage? Fantastic!

-I know, I know.

If you look down there you can see the river.

Oh, my god, it's a proper river.

Yeah, no-one's been down there ever.

We're the first people here.

There's a waterfall down there.

Come on, without further ado.

This new passage is drawing them down a side channel of the main river.

Oh, I'm soaking!

It's steep and it's getting narrower

but it could be a new way out of the mountain.

I don't know if you can make this out,

we haven't really got enough light to show,

but we're sitting at the top of a white water cataract

which is raging off down into the mountain.

And we're going to tread really carefully but I think,

do you think, Moose, we should try and push on a little bit?

-Stick to the right-hand side and then we'll cross over.

-OK.

In his treetop, Gordon is in position

but everything is against him.

BUZZING

Bloody bees!

Get off.

He's level with the Raggianna display site

but the heavens have opened.

Little chance of these birds showing up.

It's pouring down and apparently

Birds of Paradise don't like to display in the rain.

-I can hear them off... There you go, there's one.

-BIRD CHIRPS

But the chances of them coming in and doing their stuff, I would say, would be very slim.

Come on, you monkey.

Oh. Jeez, there's one there. There's one there.

Oh, you little darling.

Oh, jeez, there's two of them, there's' two of them!

Wow! Look at that.

Despite the rain, there are two males trying to outshine each other.

That is the most weird and fantastic bird I've ever seen.

What's going on, what's going on?

They're trying to show who's the fittest

with a complicated dance routine.

Wow!

It almost looks as if the males are showing off to each other.

OK, there must be a female around.

Until a female turns up, these males can't afford to stop their display

and Gordon can't afford to take his eyes off them.

There's a huge volume of water pushing through here.

It's a good job the ground's grippy.

In the cave, the route they found is getting treacherous.

You're best standing on the ridge, that's it.

This is no place to lose your grip.

-Oh, look at that.

-We're going to cross here.

This is extraordinary. It's a real raging, raging river.

There's an incredible amount of water passing through here.

If you actually lost your footing and got swept away down there,

you could get sucked into a place where the water just goes underground

with no air or you could just get swept over the top of a waterfall.

Same time, though, this has got to be one of the most exciting things I've ever done.

Every single step we take is new, no-one's ever seen any of this.

Finding and exploring a brand new underground route

is the ultimate thrill for any caver.

It's a waterfall.

We're in the top of a waterfall.

You can hear the noise of it. It's like a 747 taking off.

The passage goes off in that direction

so we've got some more exploring to do.

That's fantastic!

To descend any further, they'll need climbing equipment.

The guys have kindly said I could go first,

so I'm going to head down, see what we can find down there.

See you at the bottom, mate.

This is an absolutely awesome place.

It's just thunderous.

Honestly, just the noise of it

makes you feel like you're being battered the entire time.

Heading down there now, into the unknown.

Go, go, go, go!

That is the biggest scorpion I have seen yet here.

In the jungle, George is out collecting.

Come on, we want something nice.

The base camp phase of the expedition is nearing an end

but the forest is still delivering surprises.

There's a little tiny frog, a little tiny frog just sitting on that leaf.

Think we should collect that for Alan, our frog expert.

Alan, I bring you frog.

Is it a tree frog, very sort of adhesive little feet?

Indeed it is a tree frog. It's an interesting one, this is a great one.

Wow, it's the first one we've found here, we have not found this yet.

It could either be a new species or on it's way to being a new species.

-Yes!

-Thank you so much.

Across the lab, photographer Ulla has set up a time-lapse studio.

That's looking so close.

One of George's mystery caterpillars is now a chrysalis

and could hatch at any time.

What I really want is to give it a little poke just to see if it's...

I can't just give it a little poke, no?

Well, no, it would really spoil the time lapse, so sorry.

The cameras should capture the very moment it emerges.

I know what's going to happen.

It'll emerge and it'll be the most tedious, boring little moth.

Oh, no, I don't like the look of this at all.

This is the way on...

Well, possibly.

The water seems to have levelled out a little bit

and it goes underneath a narrow ceiling here,

and it looks like there might be more beyond it.

What do you reckon, Moose?

I reckon it's a duck of about four-five metres.

You know this is about the worse thing you could do

is to go into the unknown in fast-flowing water,

cos you get whisked away, yeah?

Only Steve and Moose will press on into the unknown.

The rest of the team can only wait.

In the tree top, Gordon's two male Raggiannas are upping their game.

Their efforts have attracted a potential mate.

Oh, there you go, female.

She'll decide which is her favourite.

Now this could get quite interesting.

Despite the rain,

they're both putting in this display because there's competition.

And not only is there competition,

there is a female around and that's what it's all about.

Oh, man,

doesn't get much better than this.

Not when it comes to birds.

Oh, two females! Jeez.

A second female also shows an interest.

Come on, I see what you can get.

Oh, he's pecking her, oh easy on.

This is quite incredible

that these birds have evolved to look like this, to sound like this,

to act like this just to win a mate.

Well, it looks as if she's decided who she likes.

Oh, yes, you will be mine.

As one male makes the biggest impression, the second knows he's beaten.

Oh, mating, he's mating, oh, lovely.

Oh, I can't believe we've got that.

Now I wonder if he'll actually mate with both of them in the one day.

This male's done well, he's won over the second female.

She is not boring at all.

He looks really doing his stuff.

That's what it's all about with Birds of Paradise,

is if you look that great you're going to get more than one lady.

And off she goes.

You don't really get too many days like this.

Off he goes, beautiful. Ta-da.

Oh, lord. This goes on forever.

Steve and Moose have been alone inside the flooded cave for 15 minutes.

The river's deep and the ceiling is getting lower.

It's not as hectic as it was the other side.

But it's still running quite fast.

Then the river disappears into an airless chamber.

As far as exploration of this part of the cave is concerned,

this is the end of the line.

Don't want to get washed into a watery grave down there,

so let's not go any further.

There's no way the cavers can go on.

There's nothing more here for us. Let's head out.

You know, we've reached the end, that's what we came here to do.

We've actually found the end of this piece of passage,

and now I think it's time to head home.

The caving has been a success.

They've found and charted a section of cave never before seen.

But for Steve, the expedition is far from over.

While George is asleep in his hammock, something stirs in the lab.

The time-lapse camera watches as a moth chooses its moment to emerge.

George?

Oh, that's beautiful, look at that!

Absolutely...

please don't fly off.

I have never seen a moth like this before in my life.

Don't fly off, please don't fly off.

Just look at the pattern on the back of that wing.

Wow, they are amazing.

When you see something in the wild

and you don't know if it'll be a moth or what sort of moth,

and the only way of finding out what any immature stage will become

is to rear them up, which is exactly what we did.

My wife has her birthday today and I'm not there,

and if these turn out to be new species, I will name them after her.

I really hope they are new species.

In base camp, Steve is preparing for the next challenge of the expedition.

The team's new destination is the volcanic crater of Mount Bosavi.

Its fortress walls have kept the hunters out and animals in.

This isolated cauldron could conceal spectacular new species.

Steve, look at that.

There it is, Mount Bosavi. I've got to say it's so much like

something you'd expect to see in a geography textbook.

This whole volcano is a million years old.

The last time it blew up was 200,000 years ago.

Yeah, sounds about right, so potentially

everything that's in there's been trapped in there for 200,000 years.

So the great thing is, of course, is that also if there is any hunting

it tends to be done on the low-lying part.

Who is going to climb up into the crater to hunt stuff

when you don't have to, so this whole area is going to be really...

Very, very exciting.

-You talk about lost worlds, well this is just, it doesn't get any better than this.

-It is amazing.

Steve is leading the advance party,

paving the way for the rest of the team.

Come on, guys, good luck.

They're going to build a camp right in the heart of the crater.

The survey of the animals around base camp is now complete,

and its time to move on.

In just four weeks, the scientists have found and catalogued hundreds of animals.

A staggering 29 are believed to be completely new to science.

Yeah, the trip's been really great.

We were able to get a lot of birds in the nets, a lot of bats as well working with Alanna.

We have well over 90 species between us

and I haven't even made the final total,

it will probably be even more than that.

The next destination is beyond the clouds.

The ancient crater inside Mount Bosavi itself.

They'll be the first scientists ever to explore this lost world.

This is the crater rim we're about to cross now. And that is the crater.

I didn't prepare myself for the size of it.

All the wildlife, all the plants

that are here have been trapped inside by all of these walls.

It's almost like the inside of the crater is kind of like an island.

We could find something really, really spectacular inside here.

I guess that's the hope.

Next time, George witnesses the birth of a new mountain.

To be absolutely honest with you I'm actually feeling quite apprehensive.

You couldn't speed away from this in a hurry, you would be toast.

In Bosavi's crater, the team find kangaroos that live in trees.

The fact that this animal just wandered straight past us

means the wildlife here has never been hunted before,

it hasn't seen people before.

And the most significant discovery of all, a new species

of mammal, the largest of its kind anywhere in the world.

Oh, my word, have a look at this.

Oh, gosh!

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