Original subtitles

This is the Komodo dragon.

The biggest lizard on the planet.

Science discovered the dragon just 100 years ago.

But the giant's story extends across millions of years.

The dragon has long been seen as a prehistoric creature

from a lost world,

and we're beginning to realise

there's far more to this lizard than meets the eye.

Today, scientists are teasing secrets from the dragon

by delving deeper into their lives than ever before.

As you can see, it's destroyed

the ability of the blood to form the blood clot.

There's something in their mouth that affects the blood coagulation.

And with modern technology, they are able to see the dragon

in a completely new light.

I would say that the Komodo is a more sophisticated killing machine

than lions and tigers.

A century on since its scientific discovery,

we're just beginning to uncover the secrets about the dragon

that reveal this lizard as a true wonder of the natural world.

The largest lizard in the world attracts a lot of attention.

Around 40,000 people come to Komodo National Park every year

to see the legendary dragon.

Their home is an extraordinary place.

Where else in the world would a tourist be allowed

to stroll alongside a top predator?

One known to kill humans.

The dragons are named after the Indonesian island where they were first discovered,

but we now know they are also found on several neighbouring islands.

Together, these are home to some 4,000 dragons.

It's not just tourists who have beaten a trail to see the dragons.

Over the last 100 years, scientists, filmmakers and explorers

have staked their reputation on the big lizard.

Today, the dragon has become something of an obsession

for this man, Australian biologist Dr Bryan Fry.

A leading authority on snakes,

Bryan recently turned his attention to the hunting strategy of lizards.

He has a hunch that there's a lot more to discover about the way dragons kill their prey,

and a visit to the island of Rinca

will allow him to study dragons in the wild.

Hello, sir. Hi, good morning, how are you?

Bryan. I'm Kevin.

Kevin, a ranger with Komodo National Park,

will be showing Bryan around the island.

But first, there's the crucial matter of health and safety.

So how do you use the sticks?

We just use the stick to push the dragon around the nose.

He will feel sensitive and run away.

Dragons often gather round the rangers' huts,

using the shade to keep cool.

And they are as inquisitive of people as people are of them.

Luckily, Bryan's stick

is an effective deterrent against this nosy dragon.

You can see the huge throat that they have.

Komodo dragons and other monitor lizards have a bone in their throat

they use to inflate their throat out,

and that's one of the things that allows them to swallow such huge meals.

They can eat up to 80% of their body weight in a single serving.

Satisfying their big appetites seems low on today's agenda

for these docile dragons.

We have five Komodo dragons here

and they're all just -

oh, this feels nice - laying down on this nice, cool earth.

Out in the sunshine it's about 105 degrees.

In the shade here, it's still about 90.

So they're moving back and forth

in between the sunlight and the shade to cool off.

And just laying down like this, it feels really nice.

You can see the big, big tail.

If he slapped me with that tail, it would probably break my cheek.

But they don't think that I'm food, they don't think I'm a threat,

so they're just watching me.

But I have my trusty little stick here in case things go awry.

They look like they're just sleeping. Stand up, run away!

If you're going to get close to dragons, you must be able to move fast.

Luckily, this is just a small skirmish between two tetchy individuals.

In dragon society, big means powerful.

So when two heavyweights of roughly equal size come together,

there can be only one outcome - a fight.

Only when dragons fight do you get a real sense of their power and size.

For many years following their scientific discovery,

we had no idea how big these dragons could grow.

We now know the biggest males can grow to over three metres

and weigh up to 100 kilos.

To get a better idea of where the dragons are hunting

and what they are killing,

Kevin and Bryan must head away from the rangers' station.

Dragons are often found around waterholes,

where they cool off in the heat of the day.

During the dry season, water becomes a rare commodity

and must be shared with other beasts.

Although they get most of the water they need from their food,

they will top up with an occasional drink.

But waterholes are also a perfect spot

for dragons on the lookout for lunch.

It's late afternoon, it's really hot.

The buffalo are here to escape the heat and it's a good opportunity

for a Komodo dragon to come down and do a bit of hunting.

It's not just the buffalo,

but the pigs and the deer will also be coming down to have a drink

and you often find Komodo dragons, particularly in the dry season like this,

hanging around the waterhole, just like if you were in South Africa,

you'd find the lions circling the waterhole or crocodiles in the water.

On the surface, these animals don't seem particularly cunning or calculating,

but anecdotal evidence suggests dragons are smarter than the average lizard.

They are keenly aware of everything going on around them,

even when their eyes are shut.

Komodo dragons are extremely alert.

It's easy to confuse lack of movement with lack of awareness.

He's not missing a thing.

I'm sitting here playing a little game with him

where, when I open my eyes,

he's closing his eyes and pretending to be asleep.

But the minute I close my eyes,

he pops his eyes open and starts checking me out.

So he's just pretending like he doesn't know I'm here or doesn't care.

But as soon as I pretend to go to sleep, he opens his eyes.

Gotcha!

They're able to think, they're able to almost plot a bit.

They're more like a mammalian predator,

so they're much, much smarter than you'd give them credit for normally.

As cold-blooded reptiles, dragons can sit for hours

assessing the situation around the waterhole,

waiting patiently for the perfect opportunity.

Water buffalo were introduced to these islands by Dutch colonists.

The heaviest weigh in at a tonne,

a hard catch for even the biggest dragons.

But a lame buffalo is an entirely different proposition.

Dragons have an incredible sense of smell,

using their forked tongues to taste the air for odours.

It's thought they can even detect a pregnant buffalo by the smell she emits

and will follow her relentlessly,

devouring her calf as she gives birth.

So the smell of a bloody cut

to a buffalo's leg is enough to rouse their senses.

And with excellent eyesight, they can easily distinguish

the lame from the healthy.

They can quite literally smell the buffalo's weakness,

and several dragons soon circle the hapless animal.

Each bite, when it happens, is quick and glancing.

The dragons are not working as a team.

Each dragon is acting alone, in its own interest,

though when the buffalo finally dies,

the meal WILL be big enough to share.

The most remarkable thing about this scene

is that no other lizard on the planet is able to kill in this way.

The dragon has somehow broken ranks from other lizards

to become a killer of prey much larger than itself.

Bryan and his colleagues believe this evolutionary leap happened

not in here in Indonesia but thousands of miles away

in Australia.

This is a paradise for monitor lizards,

close relatives of the dragon.

20 species live here, and they come in all shapes and sizes.

The monitor lizards include

some of the biggest natural predators in Australia.

And there is one particular Australian monitor that provides

an important connection to the dragon.

This is the Australian lace monitor.

It's the closest living relative of the Komodo dragon.

You can see the close relationship in the features that they share.

They both have scales with little bits of bone inside of them.

They've got the long tongue with the exquisite sense of smell.

There's a lot of misconceptions

about the lace monitor and the Komodo dragon

where a lot of people think of them just as scavengers,

but they're actually very efficient predators.

Any good predator will certainly scavenge a prey,

but just because they eat carrion and other dead prey

doesn't mean that they're not very adept hunters in their own right.

The way a lace monitor lives today gives us an idea

of how the Komodo dragon's ancestor hunted prey millions of years ago.

The lace monitor is an agile tree climber.

Its long claws allow it to grip the smooth gum-tree bark.

This particular tree has attracted the attention of a lace monitor

because it's the home of a female possum with babies in her nest.

POSSUM HISSES

The possum's noisy defence forces the monitor to retreat.

But hunger drives the lizard to make a second attempt.

Lunging into the possum's nest looks suicidal,

yet the monitor seems hardly to notice the possum's bite.

It takes less than a minute for the lizard to devour

the baby possums inside the nest.

It's not hard to imagine a smaller ancestor of the Komodo dragon

hunting in trees just like the lace monitor.

But at some point in Australia's past, this all changed.

Some monitor lizards became big - very big.

Palaeontologist Scott Hocknull has been piecing together the past lives of these reptiles.

The evidence comes in tiny fragments but, like a jigsaw,

builds a picture of a lost world of giant lizards.

What I have here is Megalania.

This is the largest lizard to have ever lived.

It's about five metres long, maybe even getting to six metres,

so it's an absolute monster of an animal.

Found in Australia, lived between

about 500,000 years ago and 50,000 years.

As well as the giant Megalania fossils,

Scott has found evidence of another large lizard -

not as big as Megalania,

but certainly bigger than any other lizard living in Australia today.

Originally it was thought that these bones

were simply a small Megalania, a small individual.

But when we look at the bones carefully

you can tell that they're actually from adults,

so they were fully-grown. So what that shows is that

it was a completely different species.

When we compare the bones of this animal

to all of the living and extinct monitor lizards,

all the fossils that exist, what we see

is that it's very much the same as a Komodo dragon.

In fact, it's so similar, it's the same species.

So this is concrete evidence that in Australia, Komodos existed,

they lived four million years ago,

and it's most likely that they originated here.

Prehistoric Australia was full of giants.

Back then, prey animals were dangerous quarry

because of their size.

To catch big prey, it helped to be a big predator.

The standard body shape of a regular monitor lizard became super-sized.

The Komodo dragon was one of the most successful of these giants,

evolving from a smaller ancestor into a giant predator.

Today, Australia is no longer home to giants.

At some point, they disappeared.

Around a million years ago, Australia began to dry out,

and, as its forests contracted,

the dragon population slowly dwindled.

But some found a new home further north.

Back then, a land bridge linked Australia to part of Indonesia.

But the islands where dragons live today

were never joined to a mainland.

There was only one way

dragons could have reached the central Indonesian islands.

By swimming.

For a three-metre-long animal weighing 100 kilos,

the dragon is a very good swimmer, able to cross deep-water channels.

The first migrant dragons that reached these central Indonesian islands would have been in paradise.

No other predators lived here, so that meant no competition for food.

But for every castaway washing up on a beach,

there is the possibility it will spend the rest of its life alone.

So how did these Robinson Crusoes of the dragon world

actually establish a population on these islands?

It's only recently that we've discovered

another extraordinary secret about the dragons.

In extreme situations, females can reproduce without a male.

It's a phenomenon that in a human would be seen as miraculous.

Somehow, the dragon's body senses

that normal conception isn't possible, and her dividing egg cells

effectively create a sperm substitute,

enabling her to fertilise her own eggs.

For stranded dragons, it's a regular part of their desert island survival kit.

After almost eight months of incubation,

dragon eggs hatch deep underground.

Their first instinct is to climb upwards and out of the nest.

These first few moments in their lives are perhaps the most dangerous.

Staying on the ground makes them vulnerable to predators,

and that includes bigger dragons on the lookout for a small snack.

So the hatchlings must quickly head up into trees for safety.

Young komodo dragons are lithe and agile

and bear little resemblance to the lumbering adults

that stalk the ground beneath them.

But as they grow up, they eventually come back down to the ground

and transform into bulky giants ready to hunt big prey.

It's easy to see why locals call the dragon a land crocodile.

But despite its size and bruising appearance,

there is one part of the dragon that is nowhere near as strong as a crocodile's.

Its head.

If you look at the skull,

it's actually quite small relative to that massive body

and that's because they need a very lightweight skull

in order to move fast when they're chasing down their prey.

And the speed at which they can swing their skull

while running is amazing.

They're very, very agile animals.

We're only just discovering the remarkable, complex relationship

between the design of the dragon's skull and its killer bite.

Bryan Fry's colleague, Stephen Wroe, has examined the skulls

of many top predators.

He's created a computer model of a skull based on a real dragon.

In this case, we were fortunate enough to have

a whole specimen of a komodo dragon

and we were able to actually dissect the muscles out

and come up with estimates

for the cross-sectional area of the individual muscles.

So that allows us to get a pretty good estimate for the sort of forces

that this animal would be able to apply in the jaws.

By recreating how a dragon bites,

he's revealed a serious weakness in this animal's jaws.

Its ability to bite down very hard just using its jaw muscles,

its skull's not really well adapted to do it.

The red and white colours indicate stress, and clearly show

that a dragon biting down hard could easily break its jaw.

Its bite forces themselves are weak.

For an animal of its size, it has a very weak bite. In fact,

by our predictions, they're smaller than that of an average house cat.

Despite its super-lightweight skull,

the dragon is able to kill prey weighing up to a tonne.

The secret to its success is in the way it uses its skull.

Hidden inside its mouth are 60 amazingly sharp teeth

that wouldn't look out of place in the mouth of a great white shark.

Each tooth is backward curved and serrated,

making them ideal slicing tools.

But to really take advantage of its weaponry,

the dragon has to bite in a very precise way.

When it bites in,

the head comes in at a slight angle.

It then pulls back

and, in doing so, it basically uses a can-opening motion,

so it's using leverage around its body instead of just its jaws.

That helps drive the teeth in and cause major damage.

So it's not the jaw muscles themselves

that are doing the serious damage here,

it's the very powerful forearms

and shoulders that are really driving this whole process.

And it's actually a very clever use of leverage.

Scientists have called this the "grip and rip" bite.

The dragon uses its sharp teeth and muscular body

so it doesn't need a heavyweight jaw.

It's a combination that allows the dragon to be a fast ambush hunter

with one of the best killer bites in the animal kingdom.

With a big dragon like this and a water buffalo,

they can kill them but it takes repeated bites over several days.

What happens is that when they do the grip and rip,

they'll do that several times and every time they catch up with the water buffalo

they'll hit him again, and this will leave more and more wounds on it, and they'll keep bleeding.

But with something much smaller like a deer or a pig,

90% of the attacks are fatal

and, in fact, 75% of them don't even survive the first contact.

The majority of them will die immediately,

some will last three or four hours

but only 10% of a natural prey item will survive the initial attack.

Those are the kind of numbers that a lion would love to have.

The fact that these giant lizards are able to kill so quickly and efficiently

makes living alongside them a little worrying.

If dragons are meant to keep out of villages,

someone has clearly forgotten to tell THEM.

And the temptations of village life are all too obvious.

Bryan is keen to find out more about the difficulties of living with dragons,

so Kevin is taking him to the local police station.

Hello. Hello.

THEY SPEAK INDONESIAN

Bryan.

How are you?

The police keep a log of all incidents involving dragons.

So, Bryan, look at here.

Accident here. Oh, here's 30 August and 31 August.

So what happened on the 23rd? What happened there?

Right here - one Komodo dragon was kill one deer around the spring water. OK.

And the last moment, 24, the police patrol around the village here,

and saw one Komodo dragon was killing one goat, 24th.

So two days in a row they had dragon problems.

So the killing of a goat,

that's property and food, so that's an economic impact to the village. Yes, yes.

In this part of the world,

livestock often live in or around

the homes of the people who own them.

But that risks attracting dragons into the heart of the village.

Goats and chickens are an easy meal for dragons,

but people have also been killed.

Children are most vulnerable, and although attacks are rare,

police records reveal just how cunning dragons can be.

One teacher, in 1998, climb on a tree

and when he go down, Komodo already waiting.

Oh, right, so the Komodo saw the person go up the tree

and came over and sat and waited? Yes. Smart lizard.

So what happened to that person? Did they die?

People didn't die at the time but two years later,

two years later he is dying. Right.

But according to the people around here,

they believe he die because of the bacteria.

Here in Rinca, with the local villagers,

they quite rightly fear the dragons

because the dragons have killed villagers

and there's also a big economic impact

where they're regularly taking goats and other livestock.

It is interesting, though,

that people believe things about the dragons

that just can't be accurate.

For example, one person was bitten, bled heavily, but he recovered.

Two years later he died.

In the intervening period he wasn't sick,

it's not like he was wasting away, he was healthy,

but when he died two years later, they blamed it on his dragon bite.

Now, we don't know what he actually died from,

but there's no way that that was from the dragon bite.

"Infection" is a word you often hear when people talk about dragons.

Death by infection through a dragon bite is an idea

that has been around for 30 years.

The story goes something like this.

Komodo dragons have dirty mouths full of lethal bacteria.

When the dragon bites, it infects its victim with bacteria,

so if its bite doesn't kill, the infection will.

It's a story so wonderfully horrific it has been endlessly retold,

and today is one of the most well-known "facts" about Komodo dragons.

Just ask the tourists.

From what I've read, it's the bacteria

from the mouth of the Komodo

that actually leads to the slow death of the prey.

They've bacteria in their mouths, they can kill large water buffalos.

It's a sort of slow death bacterial release, you know,

so sort of very painful.

They've got mouths full of bacteria, which sounds nasty.

Dragons are not unique in having bacteria in their mouths.

A bite from a human could leave the victim with a nasty infection.

But do dragons really use bacteria

as a weapon to help them kill larger prey?

Even with its slasher bite, the lightweight skull of a dragon

means it could face serious injury when preying on a buffalo.

Buffalo can be as much as ten times the weight of an average dragon.

So an additional weapon like killer bacteria would certainly help.

It's a good story,

but Bryan just doesn't buy it.

It's been a bit of a puzzle to me

of how the whole idea of the bacteria

being part of the predatory behaviour of the Komodo dragon

became such gospel.

It's never actually been proven,

it's never actually been shown that they're using bacteria.

With their natural prey item,

they're killed by the massive blood loss.

With something like a water buffalo, that's going to colour our observations.

Imagine, if you will,

one of these being bitten by a Komodo dragon and surviving,

and then hanging out in water like this.

What do you think's going to happen? It's going to get an infection.

Is that linked to the feeding behaviour of the Komodo? No.

While some people believe infection comes directly from the mouth of the dragon,

Bryan's visit to Komodo National Park has shown him

that there are many other potential sources,

not least the rotten water

where the dragon's prey loves to wallow.

But there's something about the bacteria story

that reminds Bryan of the hunting strategy of another type of animal.

One that he has studied for most of his career.

The snake.

There's one particular thing about snakes

that has fascinated Bryan for years.

Venom.

This inland taipan has one of the most venomous bites on the planet

and Bryan regularly collects its venom for analysis.

Like many snakes, it strikes quickly at its prey,

retreats, and waits for its victim to die.

It sounds suspiciously similar to the so-called bacteria bite

of a hunting dragon.

Bite, infect, retreat and wait.

Could the bite of a dragon, the largest lizard in the world,

actually be venomous?

It may not be such a crazy idea.

After all, snakes and lizards are closely related

and share a common ancestor.

Today, there are just under 4,000

species of lizard living on the planet.

But two of these lizards stand out from the rest

for one important reason.

Their venom.

And this is one of them - the Mexican beaded lizard.

A bite from one of these is painful

and in severe cases can lead to complete respiratory failure.

So if two species of lizard use venom,

why not more?

And why not the Komodo dragon?

A hospital in the Netherlands

seems an unlikely place to find the answer.

But Bryan has always believed the best discoveries

come from taking a different look at a familiar subject.

This hospital boasts one of the best MRI scanning departments in the world,

which is great for looking inside the heads of human patients.

Thankfully, that's not what Bryan is carrying.

There they are, let's have a look.

He has two pickled lizards on loan from a local museum.

The first is the venomous Mexican beaded lizard.

The second is the head of a female Komodo.

Close up, the dragon's head has some features

that makes Bryan think an MRI scan is worthwhile.

You can see very clearly that

there's something that's running the length of the lower jaw.

But by pressing on it, I can feel that it's not the jaw bone -

it's soft.

That's definitely glandular material, that's not calcium.

So the first thing we'll do is do an MRI of the beaded

and then that'll be our control because we know about that gland

and we've a good handle of what it's supposed to be like from published reports.

And then once we acquire that data, we'll then put the Komodo dragon in

and we'll be able to compare and contrast between the two of them.

The MRI scanner is usually used to look inside the heads of patients,

helping diagnose illnesses such as cancer or Alzheimer's.

This is the first time it's being used

for something of a more reptilian nature.

So let's see what we're going to find.

The beaded lizard scan has taken two hours

and the images allow Bryan

to take a fresh look at a lizard already well-known for its venom.

So these are the results. All right, so let's count the compartments for the beaded lizard.

A bit further...there, stop, stop, right there.

So, with the beaded lizard, it's supposed to

only have one duct coming out.

That's a second duct over there.

Yeah. And then here's a third one, here's a fourth one, five, six.

So it's got six compartments in it.

'With just the one scan we've done right now'

we've shown that it actually has six compartments.

So even the animals that are well-known as being venomous,

we can learn a huge amount just by using this kind of technology

that has never been applied towards these kinds of animals.

Next, it's the pickled dragon's head.

Let's see, which part do we need to see? Lower jaw, here.

It wasn't exactly designed in mind with the Komodo dragon

but we're learning so much by doing it

and it's such an incredible privilege to be able to do things

like put a Komodo dragon head in an MRI.

I'd say this is easily the coolest thing I've ever done in science.

So...

Oh, this is great.

It's so cool to see this. We did it.

What started as a hunch has now been confirmed by modern technology.

Look at the size of that internal lumen.

The Komodo dragon does indeed possess a venom gland.

This is our gland here.

There's a big posterior compartment

and you can see the duct starting to emerge there.

Not only do they have this gland,

but it's a very well-developed intricate structure,

so how did people miss this?

It's an extraordinary find that has gone unnoticed for 100 years.

I'm just so pleased to see this - it's incredible,

this is all my Christmases come true,

that we've been able to show that it's got, not just a gland,

but a very intricate gland.

All this stuff about the bacteria is now called into question by this.

It's taken a modern medical tool

to reveal the dragon's hidden venom gland.

But there are many types of venom.

Bryan's next task is to find out what sort,

and to do that he must look into the mouth of a dragon.

It's a task few would relish,

but Bryan has spent years extracting venom from dangerous animals across the world.

And, besides, not all dragons are scary man-eaters.

Bryan knows a dragon with just the right personality

to help in his research.

It lives in Bali Reptile Park

and happens to be very, very friendly.

This is Monty, by far my favourite animal on earth.

I've known him for years now

and we have a bit of an understanding.

What we're going to do is

we're going to have Monty bite down on this

and by the pressure being transmitted along the jaw,

it deforms the jaw slightly which squeezes the venom out.

They don't have the compressor muscles like a snake has,

and instead the venom

just more oozes rather than being put through like a syringe.

All right.

Perfect, yeah. Just keep it exactly like that.

So as he bites down...

..that squeezes.

That's enough.

So we've got just a little bit of his venom,

he's got a lot more in there but we don't want to stress him out,

he's, of course, such an accommodating animal.

Sorry, Monty.

Forgive me?

Yeah, I'm forgiven.

All right.

He has some venom, but Bryan needs one final ingredient

to complete his test.

His own blood.

He adds the first sample of blood to some water to act as a control.

The second is mixed with Monty's venom, then left for 20 minutes.

Here are the results of our 20-minute blood test

where in the tube without any venom, it forms a nice normal blood clot,

while the tube with the sample from Monty, as you can see,

it's destroyed the ability of the blood to form the blood clot.

And that's exactly what would happen to a prey animal,

that's why they continue to bleed,

and it's a very illustrative way

to show that there is something in the venom that affects the blood.

This is an amazing discovery.

The ability of Monty's venom to prevent blood clotting

isn't just a revelation for zoologists -

it could open up new leads in the search for new medicines.

It'll take Bryan time to analyse the full nature of the venom

but he knows from past experience

that venoms can provide us with new superdrugs.

We now know that a small group of islands in the middle of Indonesia

are home to the largest venomous animal on this planet.

It's taken science almost 100 years to realise this.

In hindsight, the clues were there all along.

If you look at the lower jaw you can actually see a bulge -

that's the venom gland.

If you look in the old reptile anatomy books, it's not in there.

But if you look at the animals, it's a very obvious structure.

The way to think about is that it's a combined arsenal,

that the teeth are the primary weapon,

that's their first line of attack.

And then what the venom does is it exaggerates the effects

of the blood pressure

so it's basically working in harmony with the teeth.

It keeps the animal bleeding, drops the blood pressure further

and the closer you get towards a very low blood pressure,

the sooner you reach unconsciousness.

It's likely that the dragon's venomous bite

evolved long before they reached Komodo.

We know from the fossil record

that they spent millions of years hunting the giant animals of Australia's past.

What in fact they had to eat were giant forest wallabies

and wombats and weird animals that don't exist on Komodo Island today.

So the development, the evolution of the venom, the anti-coagulant venom

has to come from its interaction with these sorts of prey.

So if you think of a Komodo dragon actually attacking and killing a large kangaroo,

venom would have been absolutely essential because of the huge feet

and the killing force of the strike from a kangaroo's hit.

The extraordinary journey of the Komodo dragon has lasted millions of years

and taken it from being a top predator in prehistoric Australia

to living as a castaway survivor on a tiny group of remote islands.

They fit in here remarkably well.

It's as if they were made for these islands.

We know now their large size

and their venomous ripping bite evolved to tackle

large animals that have since gone extinct,

but the dragon has survived by adapting to new opportunities

and new prey.

For Bryan, knowing the complex evolutionary journey

the dragon has taken makes it all the more remarkable.

The Komodo dragon's unique in that it's the last of the giants.

It's the only of these mega-beasts still in existence.

So it's a snapshot back into time when mega-fauna roamed the earth.

Modern scientific tools have at last revealed many of the dragon's best kept secrets.

It's a far cry from the early days of dragon research

when it was still a creature of myth and tall tales.

Back then, explorers were relying entirely on their wits

and enthusiasm simply to catch a dragon.

And how they did that is another story.

In 1912, the astonishing news came

that a new lizard had been discovered

that grew to the astonishing length of 12 feet

and weighed three hundredweights.

It was discovered on one tiny little island in the Pacific - Komodo.

In the 1950s, a young David Attenborough

was filming a pioneering new TV series called Zoo Quest.

Each programme was an exotic mix of travel and natural history

with the primary aim to collect exciting new creatures for London Zoo.

And the Komodo dragon was the biggest and most dangerous animal on the list.

But finding it wouldn't be easy.

When I arrived in Java and went to see the various authorities

that I needed to get permissions,

they'd never heard of it. There wasn't anybody in Java

that I could discover who knew about the Komodo dragon.

Eventually, Attenborough travelled east of Java

and after almost a week at sea, reached the island of Komodo.

There, he enlisted the help of locals

to help him find the animal they called "the land crocodile".

All that was known of it as far as I was concerned

was that it was big, I mean nothing more than that.

And the rest of it was question marks.

OK, so it's the biggest land-living lizard in the world, but why?

And why is it on that small island and nowhere else?

'We lit a fire and roasted some goat's flesh.'

It was clear from the start that even the locals had little idea

about the true nature of this animal.

'I said, "Were they dangerous to human beings?"

'And they said, "Well, there was an old man who was killed by a dragon,'

"but he was very old, you know, and he'd gone out and was sitting in the bush

"and whether he died before the Komodo dragon got to him or afterwards,

"we don't really know," they said.

'Now we had to set about building a trap.'

Undeterred by the potential dangers,

Attenborough pressed ahead with the plan to capture a dragon

for London Zoo.

'And it works.

'He put a piece of goat's flesh inside and now all we had to do was to wait.'

The rotting goat meat soon did the job

of luring dragons from the forest.

'And down came the door.

'Hastily, we piled boulders on the door so that he couldn't lift it up.

'We'd got him!'

Catching a dragon proved relatively straightforward,

but getting the dragon back to England would prove an impossible task.

Unfortunately, in the end, bureaucracy defeated us

and we weren't given a permit to export those dragons from Indonesia,

so I'm afraid they're still there.

Attenborough wasn't the first person to try to catch dragons.

In 1926, an American expedition travelled to Komodo with one big ambition.

To bring back the first dragons from the wild.

Expedition leader William Burden

was an explorer with matinee-idol looks

and a passion for the natural world.

Reptile expert ER Dunn accompanied Burden and his wife

on this daring expedition.

They would spend several weeks here shooting and trapping dragons,

and they would capture the first ever images of dragons on film.

Only two dragons would make it back alive to America.

The rest were mounted as museum exhibits.

The presence of these giant creatures from a lost world

in the metropolis of New York caused a sensation

and ultimately inspired the movie King Kong.

At first, zoo dragons were little more than entertainment for an audience.

No-one had any real idea whether or not these animals killed people,

and that might explain why zoo visitors

were happy to let their children pet a dragon's head.

Whatever the reason, it's unlikely these early dragons

were in any fit state to attack people.

Richard Gibson co-ordinates the European zoos' dragon conservation programme,

and is a curator at Chester Zoo.

We've learnt a lot about Komodo dragon needs

in the last even 30 years,

and certainly Komodo dragons

being kept outside of their natural range 50, 60, 70, 80 years ago

almost certainly wouldn't have been getting the appropriate environment.

So they probably wouldn't have been very fit and healthy.

We now know that in order for the animal to be in good peak condition,

they have pretty extreme environmental conditions that we have to replicate.

Zoo dragons have played a crucial role

in helping science understand dragon behaviour.

Dragons were once thought to be deaf and poorly sighted,

but zoo keepers soon realised

they had excellent eyesight and were able to hear.

Come on. Come on, Flora. Good girl.

Work with these zoo-captive dragons

has shown us that they are, for a lizard, an intelligent animal

that can be easily trained,

in much the same way as we train dogs today.

Good girl.

Flora has been trained to do simple tasks using food rewards.

So this is a brew of rather smelly fish juice, a bit of blood,

anything that's really stinky.

So we pour this around the enclosure

and make a trail that the dragon will follow.

Occasionally she'll find a fish head,

a little titbit to keep her motivated.

That encourages her to be active and foraging.

Couple of fish heads there to get her going.

We'd try and do some sort of enrichment every day, really.

This will just give her new smells, new things in her environment,

give her a reason to hunt around and enjoy what's going on.

Although zoos have taught us a lot about dragon behaviour,

research from wild dragons has given zoo keepers

a better understanding of the needs of these animals.

Looks very pleasant, doesn't it?

And that has helped keeper Matt Swatman improve the dragon's diet.

On a daily basis they get offered very, very small prey items.

So we give them things like day-old chicks,

small fresh-water fish, rodents.

But obviously the bulk of the nutritional content

regarding a dragon's diet takes place when we do

regular carcass feeding every six to eight weeks.

What we're doing is trying to get the dragon to use

as much of its muscles as possible

so it really has to work for the food.

Basically, in captivity, dragons have the capacity to be quite lazy

and they don't have to work very hard for their food.

So to combat that, to get them to use their shoulders

and that pulling mechanism that in the wild they'd use all the time...

In the wild when you see Komodo dragons they have beautiful muscle tone,

and in captivity we're obviously aiming to have the same muscle tone.

So by hanging the meat up like this we're hoping that the dragon's

going to use all those muscles to good effect.

Trooper is a male dragon and has been introduced as a mate for Flora,

but it seems she doesn't have much respect for him...

yet.

Last time we put them together, unfortunately she beat him up.

In dragon mating it's all about the dynamic.

Generally it's a good idea if the female has a healthy respect

or a fear of the male, really.

Breeding dragons rarely become headline news

like pandas or gorillas.

But Flora proved to be an exception.

In fact, her journey to motherhood was so exceptional,

some people hailed it as a miracle.

She came to fame a few years ago

when she was the first Komodo dragon in the world

to knowingly produce

parthenogenic offspring, virgin conception,

eggs produced that were fertile without any interaction with a male.

We didn't know about this in Komodo dragons before

so my colleague and myself, we organised for

samples from the fertile eggs here in Chester

to be analysed genetically,

and the genetic fingerprinting work that we did

demonstrated that the eggs had been fertilized without a male

and it was in fact a virgin conception or parthenogenesis.

It seems there are many aspects of dragon behaviour

that would've gone unnoticed without the help of zoo dragons.

And whether in zoos or in the wild, dragons have pleased and awed crowds

for almost a century.

But there are no doubt many more secrets they have yet to reveal

to their admiring audience.