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Natural World
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AnimalsTranscript
00:18This is the Komodo Dragon, the biggest lizard on the planet.
00:27Science discovered the dragon just 100 years ago.
00:35But the giant's story extends across millions of years.
00:42The dragon has long been seen as a prehistoric creature from a lost world.
00:48And we're beginning to realize there's far more to this lizard than meets the eye.
00:55Today, scientists are teasing secrets from the dragon by delving deeper into their lives than ever before.
01:01As you can see, it's destroyed the ability of the blood to form the blood clot.
01:06There's something in their mouth that affects the blood coagulation.
01:10And with modern technology, they are able to see the dragon in a completely new light.
01:16I would say that the Komodo is a more sophisticated killing machine than lions and tigers.
01:23A century on since its scientific discovery,
01:27we are just beginning to uncover the secrets about the dragon
01:29that reveal this lizard as a true wonder of the natural world.
01:55The largest lizard in the world attracts a lot of attention.
02:02Around 40,000 people come to Komodo National Park every year to see the legendary dragon.
02:17Their home is an extraordinary place.
02:21Where else in the world would a tourist be allowed to stroll alongside a top predator?
02:26One known to kill humans.
02:32The dragons are named after the Indonesian island where they were first discovered.
02:36But we now know that they are also found on several neighboring islands.
02:41Together, these are home to some 4,000 dragons.
02:46It's not just tourists who have beaten a trail to see the dragons.
02:50Over the last 100 years, scientists, filmmakers and explorers
02:55have staked their reputation on the big lizard.
03:01Today, the dragon has become something of an obsession for this man,
03:05Australian biologist, Dr. Brian Frye.
03:09A leading authority on snakes, Brian recently turned his attention to the hunting strategy of lizards.
03:19He has a hunch that there's a lot more to discover about the way dragons kill their prey.
03:25And a visit to the island of Rincha will allow him to study dragons in the wild.
03:31Hello, sir.
03:32Hi, good morning.
03:32How are you?
03:33Brian.
03:34I'm Kevin.
03:34Kevin, a ranger with Komodo National Park, will be showing Brian around the island.
03:39But first, there's the crucial matter of health and safety.
03:43I'm with you.
03:44I see Komodo dragon on the way.
03:45Great.
03:45So how do you use the sticks?
03:47We just use a stick to push dragon around the nose.
03:49They will be feeling sensitive and running away.
03:52Dragons often gather around the ranger's huts, using the shade to keep cool.
03:58And they are as inquisitive of people as people are of them.
04:03Luckily, Brian's stick is an effective deterrent against this nosy dragon.
04:20You see the huge throat that they have.
04:23Komodo dragons and other monitor lizards have a bone in their throat.
04:26They use that to inflate their throat out.
04:28That's one of the things that allows them to swallow such huge meals.
04:32They can eat up to 80% of their body weight in a single serving.
04:38Satisfying their big appetites seems low on today's agenda for these docile dragons.
04:43We have five Komodo dragons here.
04:46And they're all just, oh this feels nice, laying down on a nice cool earth.
04:51Out in the sunshine it's about 105 degrees.
04:54In the shade here it's still about 90.
04:56So they're moving back and forth in between the sunlight and the shade to cool off.
05:01And just laying down like this, it feels really nice.
05:06As you can see the big, big tail.
05:07If you slap me with that tail right now that would probably break my cheek.
05:12But they don't think that I'm food.
05:14They don't think I'm a threat.
05:15So they're just watching me.
05:17But I have my trusty little stick here in case things go awry.
05:26They look like they're just sleeping.
05:30If you're going to get close to dragons you must be able to move fast.
05:35Luckily this is just a small skirmish between two tetchy individuals.
05:43In dragon society big means powerful.
05:47So when two heavyweights of roughly equal size come together
05:50there can be only one outcome.
05:53A fight.
06:00Only when dragons fight do you get a real sense of their power and size.
06:20need one another.
06:36For many years following their scientific discovery
06:38we had no idea how big these dragons could grow.
06:43We now know the biggest males can grow to over 3 meters and weigh up to 100 kilos.
06:54To get a better idea of where the dragons are hunting and what they are killing, Kevin and Brian must
06:59head away from the ranger's station.
07:05Dragons are often found around water holes, where they cool off in the heat of the day.
07:14During the dry season, water becomes a rare commodity and must be shared with other beasts.
07:26Although they get most of the water they need from their food, they will top up with an occasional drink.
07:55But water holes are also a perfect spot for dragons on the lookout for lunch.
08:01It's late afternoon. It's really hot. The buffalo are here to escape the heat.
08:06And it's a good opportunity for a Komodo dragon to come down and do a bit of hunting.
08:10It's not just the buffalo, but the pigs and the deer will also be coming down to have a drink.
08:16And you often find the Komodo dragons, particularly in the dry season like this, hanging around the water hole.
08:23Just like if you're in South Africa, you'd find the lions circling the water hole or the crocodiles in the
08:28water.
08:38On the surface, these animals don't seem particularly cunning or calculating.
08:45But anecdotal evidence suggests dragons are smarter than the average lizard.
08:51They are keenly aware of everything going on around them.
08:55Even when their eyes are shut.
09:02Komodo dragons are extremely alert.
09:05It's easy to confuse lack of movement with lack of awareness.
09:08He's not missing a thing.
09:10I'm sitting here playing a little game with him where, when I open my eyes, he's closing his eyes and
09:15pretending to be asleep.
09:16But then the minute that I close my eyes, he pops his eyes open and starts checking me out.
09:22So he's just pretending like he doesn't know I'm here or doesn't care.
09:25But as soon as I pretend to go to sleep, he opens his eyes.
09:48Gotcha.
09:53They're able to think. They're able to almost plot a bit.
09:56They're more like a mammalian predator.
09:58So they're much, much smarter than you'd give them credit for normally.
10:03As cold-blooded reptiles, dragons can sit for hours assessing the situation around the water hole,
10:10waiting patiently for the perfect opportunity.
10:16Water buffalo were introduced to these islands by Dutch colonists.
10:19The heaviest weigh in at a ton.
10:21A hard catch for even the biggest dragons.
10:25But a lame buffalo is an entirely different proposition.
10:36Dragons have an incredible sense of smell.
10:39Using their forked tongues to taste the air for odors, it's thought they can even detect a pregnant buffalo by
10:45the smell she emits.
10:47And will follow her relentlessly, devouring her calf as she gives birth.
10:55So the smell of a bloody cut to a buffalo's leg is enough to rouse their senses.
11:03And with excellent eyesight, they can easily distinguish the lame from the healthy.
11:15They can quite literally smell the buffalo's weakness.
11:19And several dragons soon circled a hapless animal.
11:50So the
12:00Each bite, when it happens, is quick and glancing.
12:51The dragons are not working.
12:53Each dragon is acting alone in its own interest, though when the buffalo finally dies, the
12:59meal will be big enough to share.
13:12The most remarkable thing about this scene is that no other lizard on the planet is able
13:16to kill in this way.
13:21The dragon has somehow broken ranks from other lizards to become a killer of prey much larger
13:27than itself.
13:33Brian and his colleagues believe this evolutionary leap happened not here in Indonesia, but thousands
13:39of miles away in Australia.
13:55This is a paradise for monitor lizards, close relatives of the dragon.
14:31They both have the type of scales with little bits of bone inside of them.
14:35They've got the long tongue with the exquisite sense of smell.
14:39There's a lot of misconceptions about the lace monitor and the komodo dragon where a lot of
14:43people think of them just as scavengers, but they're actually very efficient predators.
14:47Any good predator will scavenger prey, but just because they eat carrion and other dead prey doesn't mean that they're
14:55not very adept hunters in their own right.
15:01The way a lace monitor lives today gives us an idea of how the komodo dragon's ancestor
15:07hunted prey had hunted prey millions of years ago.
15:13The lace monitor is an agile tree climber.
15:16Its long claws allow it to grip the smooth gum tree bark.
15:25This particular tree has attracted the attention of a lace monitor because it's the home of a female possum with
15:31babies in her nest.
16:12The possum's noisy defense forces the monitor to retreat.
16:32But hunger drives the lizard to make a second attempt.
16:54Lunging into the possum's nest looks suicidal, yet the monitor seems hardly to notice the possum's bite.
17:21It takes less than a minute for the lizard to devour the baby possum's inside the nest.
17:33It's not hard to imagine a smaller ancestor of a komodo dragon hunting in trees just like the lace monitor.
17:41But at some point in Australia's past this all changed.
17:45Some monitor lizards became big, very big.
17:59Paleontologist Scott Hocknell has been piecing together the past lives of these reptiles.
18:04The evidence comes in tiny fragments that, like a jigsaw, builds a picture of a lost world of giant lizards.
18:18What I have here is Megalania.
18:19What I have here is Megalania.
18:20This is the largest lizard to have ever lived.
18:22It's about five metres long, maybe even getting to six metres.
18:26So it's an absolute monster of an animal.
18:28Found in Australia, lived between about 500,000 years ago and 50,000 years.
18:35As well as the giant Megalania fossils, Scott has found evidence of another large lizard,
18:40not as big as Megalania, but certainly bigger than any other lizard living in Australia today.
18:53Now, originally it was thought that these bones were simply a small Megalania, a small individual.
18:59But when we look at the bones carefully, you can tell that they're actually from adults,
19:03so they were fully grown.
19:04So what that shows is that it was a completely different species.
19:08Now when we compare the bones of this animal to all of the living and extinct monitor lizards,
19:13it's all the fossils that exist, what we see is it's very much the same as a Komodo dragon.
19:18And in fact it's so similar, it's the same species.
19:21So this is concrete evidence that in Australia Komodos existed,
19:25they lived four million years ago, and it's most likely that they originated here.
19:36Prehistoric Australia was full of giants.
19:39Back then, prey animals were dangerous quarry because of their size.
19:43To catch big prey, it helped to be a big predator.
19:55The standard body shape of a regular monitor lizard became supersized.
19:59The Komodo dragon was one of the most successful of these giants.
20:04Evolving from a smaller ancestor into a giant predator.
20:14Today, Australia is no longer home to giants.
20:18At some point, they disappeared.
20:22Around a million years ago, Australia began to dry out.
20:26And as its forests contracted, the dragon population slowly dwindled.
20:32But some found a new home further north.
20:36Back then, a land bridge linked Australia to part of Indonesia.
20:41But the islands where dragons live today were never joined to a mainland.
20:50There was only one way dragons could have reached the central Indonesian islands.
20:56By swimming.
21:08For a three-meter-long animal weighing 100 kilos, the dragon is a very good swimmer.
21:13Able to cross deep-water channels.
21:24The first migrant dragons that reached these central Indonesian islands would have been in paradise.
21:32No other predators lived here, so that meant no competition for food.
21:40But for every castaway washing up on a beach, there is the possibility it will spend the rest of its
21:45life alone.
21:48So how did these Robinson Crusos of the dragon world actually establish a population on these islands?
21:57It's only recently that we've discovered another extraordinary secret about the dragons.
22:03In extreme situations, females can reproduce without a male.
22:10It's a phenomenon that in a human would be seen as miraculous.
22:17Somehow, the dragon's body senses that normal conception is impossible.
22:21And her dividing egg cells effectively create a sperm substitute, enabling her to fertilize her own eggs.
22:31For stranded dragons, it's a regular part of their desert island survival kit.
22:49After almost eight months of incubation, dragon eggs hatch deep underground.
23:02The first instinct is to climb upwards and out of the nest.
23:20These first few moments in their lives are perhaps the most dangerous.
23:24Staying on the ground makes them vulnerable to predators.
23:27And that includes bigger dragons on the lookout for a small snack.
23:32So the hatchlings must quickly head up into trees for safety.
23:47Young Komodo dragons are lithe and agile and bear little resemblance to the lumbering adults that stalk the ground beneath
23:54them.
23:58But as they grow up, they eventually come back down to the ground and transform into bulky giants ready to
24:04hunt big prey.
24:14It's easy to see why locals call the dragon a land crocodile.
24:19But despite its size and bruising appearance, there is one part of the dragon that is nowhere near as strong
24:26as a crocodile's.
24:27Its head.
24:29If you look at the skull, it's actually quite small relative to that massive body.
24:35And that's because I need a very lightweight skull in order to move very fast when they're chasing down their
24:39prey.
24:41And the speed at which they can swing their skull while running is amazing.
24:45They're very, very agile animals.
24:49We're only just discovering the remarkable complex relationship between the design of the dragon's skull and its killer bite.
24:57Brian Fry's colleague, Stephen Rowe, has examined the skulls of many top predators.
25:03He's created a computer model of a skull based on a real dragon.
25:08In this case, we were fortunate enough to have a whole specimen of a Komodo dragon.
25:12And we're able to actually dissect the muscles out and come up with estimates for the cross-sectional area of
25:22the individual muscles.
25:23So that allows us to get a pretty good estimate for the sort of forces that this animal would have
25:28to apply in the jaws.
25:30By recreating how a dragon bites, he's revealed a serious weakness in this animal's jaws.
25:37Its ability to bite down very hard just using its jaw muscles, its skull's not really well adapted to do
25:46it.
25:47The red and white colours indicate stress and clearly show that a dragon biting down hard could easily break its
25:54jaw.
25:56Its bite forces themselves are weak.
25:59For an animal of its size, it has a very weak bite.
26:03In fact, by our predictions, it's actually smaller than that of an average house cat.
26:12Despite its super lightweight skull, the dragon is able to kill prey weighing up to a ton.
26:18The secret to its success is in the way it uses its skull.
26:24Hidden inside its mouth are 60 amazingly sharp teeth that wouldn't look out of place in the mouth of a
26:30great white shark.
26:32Each tooth is backward curved and serrated, making them ideal slicing tools.
26:40But to really take advantage of its weaponry, the dragon has to bite in a very precise way.
26:47When it bites in, the head comes in at a slight angle.
26:51It then pulls back and in doing so, it basically uses a can-opening motion.
27:00So it's using leverage around its body instead of just its jaws.
27:05That helps drive the teeth in and cause major damage.
27:10So it's not the jaw muscles themselves that are doing the serious damage here.
27:16It's the very powerful forearms and shoulders that are really driving this whole process.
27:23And it's actually a very clever use of leverage.
27:30Scientists have called this the grip and rip bite.
27:33The dragon uses its sharp teeth and muscular body so it doesn't need a heavyweight jaw.
27:39It's a combination that allows the dragon to be a fast ambush hunter with one of the best killer bites
27:45in the animal kingdom.
27:56With a big dragon like this and a water buffalo, they can kill them but it takes repeated bites over
28:02several days.
28:04What happens is that when they do the grip and rip, they'll do that several times and then every time
28:09they catch up with the water buffalo, they'll hit them again.
28:11And this will leave more and more wounds on it and they'll keep bleeding.
28:15But with something much smaller like a deer or a pig, 90% of the attacks are fatal.
28:21And in fact, 75% of them don't even survive the first contact.
28:25The majority of them will die immediately, some will last three or four hours.
28:30But only 10% of a natural prey item will survive the initial attack.
28:35Those are the kind of numbers that a lion would love to have.
28:41The fact that these giant lizards are able to kill so quickly and efficiently makes living alongside them a little
28:47worrying.
28:52If dragons are meant to keep out of villages, then someone has clearly forgotten to tell them.
28:59And the temptations of village life are all too obvious.
29:12Brian is keen to find out more about the difficulties of living with dragons.
29:17So Kevin is taking him to the local police station.
29:36The police keep a log of all incidents involving dragons.
29:41So Brian, look at here. These have accident here.
29:44Oh, here's like 30 August and 31 August.
29:47So what happened on the 23rd? What happened there?
29:50Right here, one Komodo dragon was killed one deer around the spring water.
29:54Okay.
29:54And the last moment is at 24.
29:57The police patrol around the village here.
30:00They saw one Komodo dragon was killed one goat.
30:0424.
30:05So two days in a row they had dragon problems.
30:07So the killing of a goat, that's property and food.
30:10So that's an economic impact to the village.
30:13Yes, that's also.
30:17In this part of the world, livestock often live in or around the homes of the people who own them.
30:23But that risks attracting dragons into the heart of the village.
30:35Goats and chickens are an easy meal for dragons.
30:39But people have also been killed.
30:46Children are most vulnerable.
30:48And although attacks are rare, police records reveal just how cunning dragons can be.
30:55One teacher in 1998 climbed on a tree and when they go down, a Komodo already waiting in the street.
31:03Oh right, so the Komodo saw the person go up the tree, came over, sat and waited.
31:08Smart lizard.
31:09So what happened to that person? Did they die?
31:11The people did not die immediately at the time.
31:13Right.
31:14But two years later, two years later, he died.
31:17Right.
31:18But according along here, the people, they believe it, this is, they die because of the bacteria.
31:29Here in Rincha, with the local villagers, they quite rightly fear the dragons because the dragons have killed villagers and
31:36there's also a big economic impact where they're regularly taking goats and other livestock.
31:42It is interesting, though, that people believe things about the dragons that just can't be accurate.
31:47For example, one person was bitten, bled heavily, but he recovered.
31:52Two years later, he died.
31:54In the intervening period, he wasn't sick.
31:56It's not like he was wasting away.
31:57He was healthy.
31:58But when he died two years later, they blamed it on his dragon bite.
32:02Now, we don't know what he actually died from, but there's no way that that was from the dragon bite.
32:11Infection is a word you often hear when people talk about dragons.
32:16Death by infection through a dragon bite is an idea that has been around for 30 years.
32:23The story goes something like this.
32:26Komodo dragons have dirty mouths full of lethal bacteria.
32:31When the dragon bites, it infects its victim with bacteria.
32:35So if its bite doesn't kill, the infection will.
32:40It's a story so wonderfully horrific, it has been endlessly retold.
32:45And today is one of the most well-known facts about Komodo dragons.
32:51Just ask the tourists.
32:54From what I've read, it's bacteria from the mouth of the Komodo that actually leads to the slow death of
33:00the prey.
33:01They have a tremendous amount of bacteria in their mouths that can kill large water buffaloes.
33:05It was sort of a slow death bacterial release.
33:08You know, so it was sort of very painful.
33:10They've got mouths full of bacteria, which sounds pretty nasty.
33:15Dragons are not unique in having bacteria in their mouths.
33:19A bite from a human could leave the victim with a nasty infection.
33:23But do dragons really use bacteria as a weapon to help them kill larger prey?
33:36Even with its slasher bite, the lightweight skull of a dragon means it could face serious injury when preying on
33:43a buffalo.
33:46Buffalo can be as much as ten times the weight of an average dragon.
33:53So an additional weapon like killer bacteria would certainly help.
33:59It's a good story, but Brian just doesn't buy it.
34:05It's been a bit of a puzzle to me of how the whole idea of the bacteria being part of
34:10the predatory behaviour of the Komodo dragon became such gospel.
34:15It's never actually been proven. It's never actually been shown that they're using bacteria.
34:21With their natural prey item, they're killed by the massive blood loss.
34:24With something like a water buffalo, that's going to colour our observations.
34:28Imagine, if you will, one of these being bitten by a Komodo dragon and surviving, and then hanging out in
34:34water like this.
34:35What do you think is going to happen? It's going to get an infection.
34:38Is that linked to the feeding behaviour of the Komodo? No.
34:46While some people believe infection comes directly from the mouths of the dragon,
34:51Brian's visit to Komodo National Park has shown him that there are many other potential sources.
34:56Not least the rotten water where the dragon's prey loves to wallow.
35:05But there is something about the bacteria story that reminds Brian of the hunting strategy of another type of animal.
35:12One that he has studied for most of his career.
35:15The snake.
35:18There is one particular thing about snakes that has fascinated Brian for years.
35:24Venom.
35:26This inland taipan has one of the most venomous bites on the planet.
35:31And Brian regularly collects its venom for analysis.
35:34Like many snakes, it strikes quickly at its prey, retreats, and waits for its victim to die.
35:43It sounds suspiciously similar to the so-called bacteria bite of a hunting dragon.
35:49Bite, infect, retreat, and wait.
35:52Could the bite of a dragon, the largest lizard in the world, actually be venomous?
36:01It may not be such a crazy idea.
36:03After all, snakes and lizards are closely related and share a common ancestor.
36:12Today there are just under 4,000 species of lizard living on the planet.
36:17But two of these lizards stand out from the rest for one important reason.
36:22The venom.
36:27And this is one of them.
36:28The Mexican beaded lizard.
36:31A bite from one of these is painful and in severe cases can lead to complete respiratory failure.
36:41So if two species of lizard use venom, why not more?
36:46And why not the Komodo dragon?
36:57A hospital in the Netherlands seems an unlikely place to find the answer.
37:01But Brian has always believed the best discoveries come from taking a different look at a familiar subject.
37:09This hospital boasts one of the best MRI scanning departments in the world.
37:13Which is great for looking inside the heads of human patients.
37:18Thankfully, that's not what Brian is carrying.
37:21There they are. Let's have a look.
37:28He has two pickled lizards on loan from a local museum.
37:32The first is the venomous Mexican beaded lizard.
37:36The second is the head of a female Komodo.
37:41Close up, the dragon's head has some features that makes Brian think an MRI scan is worse.
37:51It's not the jaw bone.
37:57It's soft.
37:58That's definitely glandular material.
38:00That's not calcium.
38:02So the first thing we'll do is do an MRI of the beaded.
38:07And then that will be our control because we know about that gland.
38:10And we have a fairly good handle of what it's supposed to be like from published reports.
38:14And then once we acquire that data, we'll then put the Komodo dragon in and be able to compare and
38:19contrast between the two of them.
38:23The MRI scanner is usually used to look inside the heads of patients, helping diagnose illnesses such as cancer or
38:31Alzheimer's.
38:35This is the first time it is being used for something of a more reptilian nature.
38:41So, let's see what we're going to find.
38:52The beaded lizard scan has taken two hours and the images allow Brian to take a fresh look at a
38:58lizard already well known for its venom.
39:01So, these are the results.
39:02All right.
39:03So, let's count the compartments for the beaded lizard.
39:05Let me go just a bit further.
39:07All right.
39:08There.
39:09Stop.
39:09Right there.
39:11So, with the beaded lizard, it's supposed to only have one duct coming out.
39:15But we...
39:15Yeah, second duct over there.
39:16Yeah.
39:17And then here's a third one.
39:18Here's a fourth one.
39:20Five, six.
39:21So, it's got six compartments in it.
39:23With just the one scan we've done right now, we've shown that it actually has six compartments.
39:28So, even the animals that are well known as being venomous, we can learn a huge amount just by using
39:34this kind of technology that has never been applied towards these kinds of animals.
39:39Next, it's the pickled dragon's head.
39:42Let's see.
39:42Which part do we need to see?
39:44A lower jaw here.
39:46It's great.
39:54It wasn't exactly designed in line with the Komodo dragon, but we're learning so much by doing it, and it's
40:01such an incredible privilege to be able to do things like put a Komodo dragon head in an MRI.
40:06I'd say this is easily the coolest thing I've ever done in science.
40:15So.
40:18Let's see what it looks like.
40:20Yeah.
40:24Oh, this is great.
40:26It's so cool to see this.
40:28We did it.
40:29What started as a hunch has now been confirmed by modern technology.
40:33I mean, look at the size of that internal lumen.
40:35The Komodo dragon does indeed possess a venom gland.
40:39This is our gland here.
40:42There's our big posterior compartment.
40:45You can see the duct starting to emerge there.
40:48Not only do they have this gland, but that it's a very well developed, intricate structure.
40:54So how did people miss this?
40:57It's an extraordinary find that has gone unnoticed for a hundred years.
41:01I'm just so pleased to see this.
41:05It's incredible.
41:06This is all of my Christmases come true.
41:09That we've been able to show that it's got not just a gland, but a very intricate gland.
41:14All this stuff about the bacteria is now called into question by this.
41:21It's taken a modern medical tool to reveal the dragon's hidden venom gland.
41:26But there are many types of venom.
41:29Brian's next task is to find out what sort.
41:33And to do that, he must look into the mouth of a dragon.
41:41It's a task few would relish, but Brian has spent years extracting venom from dangerous animals across the world.
41:52And besides, not all dragons are scary man-eaters.
41:56Brian knows a dragon with just the right personality to help in his research.
42:04It lives in Bali Reptile Park and happens to be very, very friendly.
42:25This is Monty, by far my favourite animal on earth.
42:28I've known him for years now, and we have a bit of an understanding.
42:33What we're going to do is we're going to have Monty bite down on this.
42:36And by the pressure being transmitted along the jaw, it deforms the jaw slightly, which squeezes the venom out.
42:43They don't have the compressor muscles like a snake has.
42:46Instead, the venom just more oozes rather than being put through like a syringe.
42:53All right.
43:03There we go.
43:04Perfect.
43:05Yeah, and just keep it exactly like that.
43:11So as he bites down, that squeezes.
43:23That's enough.
43:26So, got just a little bit of his venom.
43:28He's got a lot more in there, but we don't want to stress him out.
43:30He's, of course, such an accommodating animal.
43:34Sorry, Monty.
43:35Can you forgive me?
43:37Hmm?
43:40Yeah, I'm forgiven.
43:44All right.
43:47He has some venom, but Brian needs one final ingredient to complete his test.
43:53His own blood.
43:58He adds the first sample of blood to some water to act as a control.
44:03The second is mixed with Monty's venom, then left for 20 minutes.
44:11Here are the results of our 20-minute blood test, where in the tube, without any venom, it forms a
44:16nice, normal blood clot.
44:18While the tube with the sample from Monty, as you can see, it's destroyed the ability of the blood to
44:23form the blood clot.
44:24And that's exactly what would happen to a prey animal.
44:27That's why they continue to bleed.
44:29And it's a very illustrative way to show that there is something in the venom that affects the blood.
44:40This is an amazing discovery.
44:43The ability of Monty's venom to prevent blood clotting isn't just a revelation for zoologists.
44:48It could open up new leads in the search for new medicines.
44:52It will take Brian time to analyze the full nature of the venom.
44:56But he knows from past experience that venoms can provide us with new super-drugs.
45:07We now know that a small group of islands in the middle of Indonesia are home to the largest venomous
45:13animal on this planet.
45:17It's taken science almost 100 years to realize this.
45:22In hindsight, the clues were there all along.
45:29You look on the lower jaw, you can actually see a bulge.
45:32That's the venom gland.
45:34If you look in the old reptile anatomy books, it's not in there.
45:37But if you look at the animal, it's a very obvious structure.
45:41The way to think about it is that it's a combined arsenal, that the teeth are the primary weapon.
45:46That's their first line of attack.
45:48And then what their venom does is it exaggerates the effects of the blood pressure.
45:52So it's basically, it's working in harmony with the teeth.
45:56Keeps the animal bleeding, drops the blood pressure further.
45:59And the closer you get towards a very low blood pressure, the sooner you reach unconsciousness.
46:10It's likely that the dragon's venomous bite evolved long before they reached Komodo.
46:16We know from the fossil record that they spent millions of years hunting the giant animals of Australia's past.
46:26What in fact they had to eat were giant forest wallabies and wombats and weird animals that don't exist on
46:32Komodo Island today.
46:33So the development, the evolution of the venom, the anticoagulant venom has to come from its interaction with these sorts
46:39of prey.
46:41So if you think of a Komodo dragon actually attacking and killing a large kangaroo,
46:45venom would have been absolutely essential because of the huge feet and the killing force of the strike from a
46:51kangaroo's hit.
46:54The extraordinary journey of the Komodo dragon has lasted millions of years
46:58and taken it from being a top predator in prehistoric Australia
47:02to living as a castaway survivor on a tiny group of remote islands.
47:08They fit in here remarkably well.
47:11It's as if they were made for these islands.
47:16We know now their large size and their venomous ripping bite evolved to tackle large animals
47:22that have since gone extinct.
47:24But the dragon has survived by adapting to new opportunities and new prey.
47:37For Brian, knowing the complex evolutionary journey the dragon has taken makes it all the more remarkable.
47:46The Komodo dragon's unique in that it's the last of the giants.
47:50It's the only of these mega beasts still in existence.
47:53So it's a snapshot back into time when megafauna roamed the Earth.
48:02It's the only of these dragons.
48:02Modern scientific tools have at last revealed many of the dragon's best-kept secrets.
48:10It's a far cry from the early days of dragon research when it was still a creature of myth and
48:15tall tales.
48:18Back then, explorers were relying entirely on their wits and enthusiasm simply to catch a dragon.
48:24And how they did that is another story.
48:39In 1912, the astonishing news came that a new lizard had been discovered that grew to the astonishing length of
48:4712 feet and weighed 300 weights.
48:50It was discovered on one tiny little island in the Pacific, Komodo.
48:54In the 1950s, a young David Attenborough was filming a pioneering new TV series called ZooQuest.
49:03Each program was an exotic mix of travel and natural history, with the primary aim to collect exciting new creatures
49:10for London Zoo.
49:11And the Komodo dragon was the biggest and most dangerous animal on the list.
49:16But finding it wouldn't be easy.
49:20When I arrived in Java and went to see the various authorities that I needed to get permission, they had
49:26never heard of it.
49:27There wasn't anybody in Java that I could discover who knew about the Komodo dragon.
49:32Eventually, Attenborough travelled east of Java, and after almost a week at sea, reached the island of Komodo.
49:38There, he enlisted the help of locals to help him find the animal they called the land crocodile.
49:45All that was known of it, as far as I was concerned, was that it was big.
49:48I mean, nothing more than that.
49:50And the rest of it was question marks.
49:53OK, so it's the biggest land living lizard in the world.
49:58But why?
50:00And why is it on that small island and nowhere else?
50:03We lit a fire and roasted some goat's flesh.
50:07It was clear from the start that even the locals had little idea about the true nature of this animal.
50:13I said, were they dangerous to human beings?
50:15And they said, well, there was an old man who was killed by a dragon.
50:22But he was very old, you know, and he'd gone out and was sitting in the bush.
50:26And whether he died before the Komodo dragon got to him or afterwards, we don't really know, they said.
50:32Now we had to set about building a trap.
50:37Undeterred by the potential dangers, Admiral pressed ahead with a plan to capture a dragon for London Zoo.
50:48And it works.
50:50He put a piece of goat's flesh inside and now all we had to do was to wait.
51:00The rotting goat's meat soon did the job of luring dragons from the forest.
51:08And down came the door.
51:10Hastily we piled boulders on the door so that he couldn't lift it up.
51:14We had got him.
51:17Catching a dragon proved relatively straightforward, but getting the dragon back to England would prove an impossible task.
51:25Unfortunately, in the end, bureaucracy defeated us and we weren't given a permit to export those dragons from Indonesia.
51:32So I'm afraid they're still there.
51:36Attenborough wasn't the first person to try to catch dragons.
51:39In 1926, an American expedition traveled to Komodo with one big ambition.
51:44To bring back the first dragons from the wild.
51:50Expedition leader William Burden was an explorer with matinee idle looks and a passion for the natural world.
51:59Reptile expert E.R. Dunn accompanied Burden and his wife on this daring expedition.
52:07They would spend several weeks here shooting and trapping dragons.
52:11And they would capture the first ever images of dragons on film.
52:21Only two dragons would make it back alive to America.
52:24The rest were mounted as museum exhibits.
52:27The presence of these giant creatures from a lost world in the metropolis of New York caused a sensation and
52:35ultimately inspired the movie King Kong.
52:46At first, zoo dragons were little more than entertainment for an audience.
52:50No one had any real idea whether or not these animals killed people.
52:54And that might explain why zoo visitors were happy to let their children pet a dragon's head.
53:02Whatever the reason, it's unlikely these early dragons were in any fit state to attack people.
53:12Richard Gibson coordinates the European Zoo's dragon conservation program and is a curator at Chester Zoo.
53:20We've learnt a lot about Komodo dragon needs in the last even 30 years and certainly Komodo dragons being kept
53:26outside of their natural range 50, 60, 70, 80 years ago almost certainly wouldn't have been getting the appropriate environment
53:32and as a result those animals probably wouldn't have been very fit and healthy.
53:35We now know and in order for the animals to be in good peak condition, they have pretty extreme environmental
53:40conditions that we have to replicate.
53:44Zoo dragons have played a crucial role in helping signs understand dragon behavior.
53:50Dragons were once thought to be deaf and poorly sighted.
53:53But zoo keepers soon realized they had excellent eyesight and were able to hear.
53:58Come on. Come on Flora. Good girl.
54:01And work with these zoo captive dragons has shown us that they are, for a lizard, an intelligent animal that
54:08can be easily trained in much the same way as we train dogs today.
54:12Good girl.
54:14Flora has been trained to do simple tasks using food rewards.
54:20So this is a brew of rather smelly fish juice, a bit of blood, anything that's really stinky.
54:26And what we do is we pour this around the enclosure and make a trail that the dragon will follow.
54:30Occasionally she'll find a fish head, something as a little tidbit to keep her motivated.
54:34That'll encourage her to be active in foraging.
54:36A couple of fish heads there to get her going.
54:43We try and do some sort of enrichment every day really.
54:47This sort of thing will just give her new smells, new things in her environment, give her a reason to
54:52hunt around and enjoy what's going on.
54:58Although zoos have taught us a lot about dragon behavior, research from wild dragons has given zookeepers a better understanding
55:05of the needs of these animals.
55:08It's very pleasant, doesn't it?
55:10And that has helped keeper Matt Swatman improve the dragon's diet.
55:15On a daily basis they get offered like very, very small prey items. So we give them things like day
55:21old chicks, small freshwater fish, rodents.
55:25But obviously the bulk of nutritional content regarding a dragon's diet takes place where we do regular carcass feeding every
55:31six to eight weeks.
55:37What we're doing is trying to get the dragon to use as much of its muscles as possible so it
55:45really has to work for the food.
55:47Basically in captivity dragons have the capacity to be quite lazy really and they don't have to work very hard
55:54for their food.
55:55So to combat that, to get them to use, you know, their shoulders and that pulling mechanism that in the
56:01wild they'd use all the time.
56:02So in the wild when you see Komodo dragons they have beautiful muscle tone.
56:06And in captivity we're obviously aiming to have the same muscle tone.
56:09So basically by hanging the meat up like this we're hoping that the dragon's going to use all those muscles
56:16to good effect.
56:23Trooper is a male dragon and has been introduced as a mate for Flora.
56:28But it seems she doesn't have much respect for him.
56:31Yet.
56:33Last time we put them together unfortunately she beat him up.
56:37In Dragon Mate and it's all about the dynamic.
56:39Generally it's a good idea if the female has a healthy respect or a fear of the male really.
56:46Breeding dragons rarely become headline news like pandas or gorillas.
56:51But Flora proved to be an exception.
56:54In fact her journey to motherhood was so exceptional some people hailed it as a miracle.
57:00She came to fame a few years ago when she was the first Komodo dragon in the world to knowingly
57:04produce parthenogenic offspring, virgin conception.
57:08Eggs produced that were fertile without any interaction with a male.
57:14We didn't know about this in Komodo dragons before.
57:17So my colleague and myself we organised for samples from the fertile eggs here in Chester to be analysed genetically.
57:24And the genetic fingerprinting work that we did demonstrated that the eggs had been fertilised without a male.
57:29And it was in fact a virgin conception or parthenogenesis.
57:34It seems there are many aspects of dragon behaviour that would have gone unnoticed without the help of zoo dragons.
57:43And whether in zoos or in the wild dragons have pleased and awed crowds for almost a century.
57:54But there are no doubt many more secrets they have yet to reveal to their admiring audience.
58:10And there's more incredible wildlife footage when we're back in the forest with the bear family and me here on
58:16BBC HD on Friday at half past seven.
58:19o
58:20o
58:20o
58:26o
58:31You
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