Dragons Alive (2004) s01e02 Episode Script

Imagine being able to fire your tongue like a ballistic missile Send secret messages underwater Circumnavigate the globe using invisible force fields Spit poison through hollow teeth Even run on water One group of animals can do all this and more so what makes reptiles so smart? Reptiles have infiltrated every corner of the planet from steamy swamps to shifting desert sands Tojungle canopy to the open seas.
But wherever they live they face the same challenges attracting a mate fooling enemies showing how they feel and what they want.
And reptiles have some very smart solutions fine-tuned for millions of years to cope with almost anything the world can throw at them! So how do reptiles call the shots? Imagine living on a remote, primeval island with no food or fresh water, and lashed by hostile seas? How long would you survive? Well, there is such a place, a land that time forg home to iguanas - large dragon-like lizards.
These are the volcanic islands of the Galapagos - and living here takes ingenuity.
Like all cold-blooded reptiles, an iguana needs a blast of morning sun to get it moving - and these rocks are great for basking.
But what about food? There's nothing to eat up here up here it's all down in the chilly waters But the iguana has an answer It soaks up as much heat it can before it takes the plunge.
The cold water kicks in immediately and the iguana's arms and legs cool down fast.
But its body core acts like a storage heater, staying warm long enough for it to reach the seaweed beds.
The bigger the body, the more heat it can store that's why marine iguanas need to be so large - up to one and a half metres long.
The iguana's favourite food is Galapagos algae fed by the cold but nutritious waters of the Humboldt current But how does it stop the current sweeping it away? Another bit of smart design huge curved claws, like an eagle's, clamp it firmly to the rocks Meanwhile, though, the storage heater's cooling down the iguana needs fast food.
Luckily it has just the right tools for the job - a blunt muzzle and trident-shaped teeth clip off seaweed as close into the rock as possible.
Packing in enough to satisfy a hungry lizard takes a while but the iguana can remain 12 metres down for up to one hour on a single breath.
The secret of this trick is saving oxygen- by slowing down its heart beat to a quarter of its normal rate.
But the sea can be a death-trap for a cold and breathless lizard A hammerhead shark can detect the electrical field of any living thing But camouflaged against the seabed with its heart beat almost at a standstill an iguana may be able to remain below the radar This time the danger's passed, but by now the iguana's body is thoroughly chilled.
It needs to get up to the hot rocks before it seizes up.
It's a tough life - but the iguana has the right technology to thrive where others would fear to tread.
But danger can wear many faces and a lizard can rarely afford to relax.
Lizards are top of the menu for a whole variety of hungry beasts So they've become experts in bluff and evasion.
They've learned the hard way that just keeping an eye open isn't always good enough.
Deep in an Asian rainforest, meet secret agent dragon-lizard.
His first tactic is to keep his head down and melt into the background.
He's in surveillance mode and nothing escapes his attention certainly not any nearby females! His drab colours won't attract them But the draco has a secret - he's a flasher! Waving his tiny flag-pole signals his availability But this time all he gets is trouble his cover's blown, the only way is up He might seem doomed, but this is the James Bond of the lizard world with the ultimate gizmo He snaps out his ribs stretching skin into colourful wings, converting into a one-lizard hang-glider This type of flying more like gliding really was adopted by the very first airborne vertebrates before birds even existed.
A flying dragon can glide 30 metres horizontally steering with its rudder-like tail.
On landing, he snaps back into everyday wear and vanishes again Same problem, different solution This collared lizard is as gaudy as they come Like the draco, he's dressed for success, to tempt the girls but it's a calculated risk! Conspicuous against the red rock of Utah in North America, he gets more attention than he wants But this lizard can afford to take more risks than most When danger threatens, he can simply leg it! By lifting his front legs clear off the ground, he gives himself a longer stride without the risk of tripping up Hey presto - a two-legged sprinter, with his own unique style.
With a stride 3 times the length of his whole body, he can do a nifty long jump too he's the gold medallist of the lizard world.
And he doesn't get as hot under the collar as the fur-coated puma.
So with the cat out of the running, he can focus on the main event finding a mate - being a colourful character can work if you've got the legs to carry it off.
But there's another leggy lizard that's taken the great escape a step further.
He's refined his own on-board technology to guard himself against the dangers of the Amazon jungle Here it's not just being eaten he needs to worry about! This is the basilisk - and he's not known as the Jesus Christ lizard for othing.
He doesn't just walk on water - he runs.
But how? With specially fringed super-Iong toes and a running speed of 20 steps a second he literally powers himself along the water surface whipping his feet out before the water skin is broken.
Of course, humans could do this too - if we could run at 68 miles an hour with 15 times our normal muscle power! So we've seen a smart runner, a water sprinter and a secret agent but speed and secrecy aren't always the best ways to avoid becoming a meal This time the predator's a South African meerkat hoping to root out a lizard basking in the sun.
But this armadillo lizard has spotted him first.
His first line of defence is spiky armour down his back - a pretty good deterrent for most enemies.
But the meerkat will even tackle stinging scorpions so it may not be put off by a few spikes.
The lizard tries to dash for cover But the meerkat's a fast runner too In this case, extreme tactics are required.
The lizard flips round, grabs its tail in its jaws, and spins itself into a prickly wheel.
Faced with frustrating prickles on all sides, the meerkat has nothing to get his teeth into.
It's all too much No meals on wheels today.
Once the coast is clear, the smart lizard can unroll again.
Getting in a spin has saved this reptile's skin.
Each reptile's box of hi-tech tricks fits its own lifestyle.
The variety and ingenuity of solutions so far have been impressive, what other secret surprises do these smart reptiles have to help them survive? For one urban lizard, the Australian skink, it's people and pets that cause most of the problems.
But it's got a simple way of dealing with a nuisance it just pulls a scary face! its that old warrior trick Again! The skink has no weapons to back up its bluff but who knows that? This time smart attitude wins the day! But a lizard doesn't spend its whole life on the run it needs to catch its own prey too.
And when it comes to specialist equipment, one lizard has got all the others licked.
This tongue means business.
It's the fastest in the reptile world, and it belongs to a Jackson's chameleon from the mountains of East Africa.
Chameleons cruise the treetops where there are lots of insects.
There's no shortage of food - the tricky part is catching up with it You might think insects should be pretty safe they have lightning reactions while the doddering chameleon is by far the slowest on its feet of any lizard But this hunter doesn't need to get too close it has a secret weapon a ballistic missile! So how does it work? Inside the mouth, things are much more complex than inside ours.
The tongue has a muscular tube surrounding a rod of cartilage.
When the chameleon's ready to strike, muscles at the back of the throat push the tongue into launch position.
Once the prey is lined up and the distance calculated super-fast muscles contract and propel the tongue forward at lightning speed But the cleverest part is the tip covered in microscopic fingers, it closes like a sticky mitt, ripping the insect from its perch.
As if on a rubber band, it recoils back into the mouth.
Steel-trapjaws and needle-teeth finish the job.
But even the most powerful missile is only as good as its guidance system.
The chameleon judges range and distance best of any reptile.
Its turret eyes move independently, missing nothing But to focus on prey, it swivels its eyes together to line up its target precisely The focus is super-smart.
It's a bulls-eye nine times out of ten.
Chameleons may be slow but they aren't passive.
Here two males size each other up They threaten with hisses and gaping mouths And if that doesn't break the stand-off, they charge rhinoceros style and into battle.
Jackson's chameleons are the only ones with specialised fighting gear a horn on the snout and two above the eyes.
Two evenly matched males may wrestle for hours until one is finally forced to retreat.
The loser slinks off to regroup, while the winner triumphantly takes centre stage Body language is one of the reptile's specialities They use accessories postures and colour To communicate Mood and emotion But the panther chameleon of Madagascar takes visual aids onto a whole different plane This is the kaleidoscope of the reptile world.
It's colour vision is even better than ours.
Colour is how it shows its innermost feelings An excited chameleon can switch from cool green to angry red in an instant.
But how does it change its skin so fast and fluently? Beneath the skin, is a double layer of simple pigment cells which expand or contract, flushing from yellow through green to blue.
Contracting both layers, reveals the white cells below, turning the skin pale.
And groups of branch cells give a red colour, turning darker or lighter as black melanin granules move up and down.
All this produces the most complex, dazzling colour coding of any land animal.
This is biotechnology at its smartest.
Imagine if we could communicate in colour Make our intentions known in a split second use a different palette to express our every mood and even disappear into the background When we felt like it But all this only works if you can see! At night, visual aids are of limited use all.
It's easy for humans, we have words to tell each other what we want.
But reptiles - like most animals - can't speak.
Or so you might think! Meet the flying gecko.
The gecko has a true functioning voice - it can bark, trill, warble and yap.
So in a simple sense, groups of geckos actually talk to each other.
As spring approaches here in Bali, gecko calls get louder and more urgent.
Inside this restaurant, geckos are courting.
The ritual uses sound alone and male to female conversation has a certain tone.
But listen to the difference when a rival male intrudes on this suitor's domain it's clearly unacceptable! Geckos back up their vocal threats with a visual display And if they're really pushed, the call goes up a gear - in gecko speak this is extremely menacing.
Finally for the rival it's a case of fight or flight and this time he decides the female isn't worth the fuss.
By using their wide repertoire of sound, these geckos can talk their way out of trouble But when it comes to sheer volume, it's the biggest reptiles of them all that have the biggest voices crocodilians huge, fearsome, capable of man-eating up to a ton in weight and with jaws to match.
But they have brains as well as brawn including a sophisticated sound system to beat that of all other reptiles.
At 100 decibels, the love song of an adult American alligator is the loudest of all reptile calls.
A deep-pitched roar means a big, powerful male And for all other males in the vicinity, it's a call to arms they can't ignore.
The males home in from far and wide, to check the singer's status, and if necessary put him in his place As more and more males muscle in to settle status issues, mayhem rules After all, there's a stretch of good breeding river at stake.
Now the chorus starts It's alligator -style Fame Academy where the winner gets the girls! But there's more to this concert than meets the ear.
Below the water-line, the singing male is shivering his flanks, producing a pulse of low-pitched frequencies which causes the water to literally dance on his back.
This infra-sound bass line isn't designed to be heard but felt, like a pressure wave.
It travels up and down the river, penetrating deeper than the airborne bellow and affecting every alligator for up to a mile in both directions.
Everyone within the sound and pressure Range receives these signals.
Alligators' lips are lined in tiny mole-like pressure receptors, sensitive to vibrations in the water.
To a male, this infrasound signalling means competition To a female, it probably feels like a seductive tingling in her lips to her his infra-sound solo is irresistible.
Ancient alligators may be, but not primitive.
Their sound system is the most complex in the reptile world.
This is a real love song with real feeling! The female is inspired to make the first move and the solo turns to a duet.
Crocodiles speak a similar language to alligators, but it's one we don't yet understand - this can lead to problems A chugging outboard motor gives out infrasound To a male croc this can feel like the lip tingles from a rival's bellows.
A big bull is extremely territorial and he won't tolerate another male on his patch, certainly not one who roars out such a threat So he sends back his own warning, telling the intruder to make a smart exit now! But he gets no response The intruding boat of course doesn't behave like a crocodile; the Motor tingles are driving the male croc mad With the offender silenced, the male can relax and peace returns to the river.
After catching prey - and making sure you don't become it - the next challenge is to find your way around Humans have learned to travel the globe using instruments and landmarks.
But how do you navigate thousands of miles in an open featureless ocean? Welcome to the secret high tech world of turtles.
This green turtle has just swum back to the island of her birth This is the first time she has left the sea and she's about to lay her very first batch of eggs.
To get here she's made an incredible journey It started years ago, on this very beach.
So lets go back in time Newly hatched, she digs towards the surface.
Once in the fresh air, she heads for the sea.
But how does she know which way to go? In a world without light pollution, the sky is a mass of stars.
She, like the other hatchlings, simply heads for the lowest point of light that way must lie the ocean On her way down the beach, she registers features of the sand that we couldn't even detect, its smell becomes imprinted on her memory.
In the first few minutes of life, each hatchling behaves like a mini-computer, storing volumes of information.
Years later this data will guide them back to their birthplace to breed.
It's hard to believe these tiny scraps of life grow up to be some of the greatest navigators on the planet.
Once our female reaches the waves, she swims at right angles to them.
And so begins a 24-hour swimming frenzy which carries her clear of the treacherous coastal waters.
What happens in the next 20 years is still a mystery.
All we do know is that turtles Swim thousands of miles to and from their feeding grounds Using an amazing form of navigational technology One which we humans have discovered only recently.
A turtle's brain contains tiny particles of the mineral magnetite - once used in compass needles.
These respond to the pattern of magnetic force fields through which they pass.
By programming in this navigation data, the growing turtle's brain builds up a map of its ocean world This memory map will guide it back to its birthplace with amazing accuracy, even after 20 years or more.
Or more.
When a female reaches breeding age she rewinds all the cues in her head to return to the place where she began.
Meanwhile, males feel the same instinct and also return to their Home beach.
So as the female approaches land, she runs into squadron of suitors.
After mating in the shallows, she hauls her heavy, egg-filled body up on to the beach.
The sand's distinctive smell, logged in her infant brain so long ago, is the final confirmation that her epic voyage has come full circle.
Who would have thought a shell on legs was so sophisticated? But there's one well-travelled reptile group that leaves the turtles standing Snakes possess a range of super senses that have helped them conquer every continent except Antarctica.
They've even managed to turn legless ness to their advantage slithering into all kinds of surprising places.
Spring arrives on the prairies of North America.
Garter snakes emerge from the big freeze, after a winter hibernating in protected cavities deep underground.
As things warm up, More and more snakes emerge Until eventually the ground is swarming with them Snakes have the smartest scent technology of all reptiles.
But they don't use their noses They're equipped with super hi-tech tongues- which trap smelly molecules wafting on the breeze.
The clever science happens in the head.
Each prong-full of scent is drawn to the mouth and then wiped over a special scent-detector.
The results are analysed in stereo, in the snakes brain, telling the snake which smells are coming from where.
This is vital information - because all these snakes are males And when the females emerge later the males outnumber them by 10 to one So speed dating is the only way to go! Each female heads off, leaving an alluring hormone trail It's guaranteed to drive red-blooded males wild with desire.
They deploy their scent detection kit to track her down And soon a mob of males are hot on every female's tail.
In generally the biggest male mates first, but sometimes smaller males manage to sneak in ahead of him Within a few hours she's the centre of a frenzied mating ball.
But the female's always in control and when she's had enough she switches perfumes- to a passion-killing stink which sends her suitors slithering away.
Snakes live in a violent world- so are they up to the challenge? well some of them have a pretty fearsome weapon.
Venom.
This tongue belongs to one of the deadliest snakes of them all an eastern diamondback rattlesnake.
Loaded with chemical ammunition It's Scanning this Florida swamp for prey There's enough venom in a single bite to kill 6 people.
This is one snake you don't want to disturb! It's as much at home in water as it is on land Which gives it a distinct advantage over us Prime hunting territory here's the target but who's going to make the kill? The snake has one big head start it can follow Scent trails with its tongue.
It also senses temperature with special pits below its eyes - it can see heat the way we see light.
It's a hungry, heat-seeking missile Having seen off the competition, the snake can get on with the job.
After tracking the rabbit with its sense of smell and thermal receptors, the snake finally lays an ambush and deploys a chemical weapon.
The strike is super fast.
To see it we need to slow down the action a hundred times.
The long hinged fangs swing forward and penetrate the flesh biting triggers the release of venom.
Hollow fangs act like hypodermic syringes, injecting the free flowing venom It's a lethal dose, but it doesn't kill instantly.
The rabbit appears to escape but the rattler is close on its trail.
The rabbit's heart is pumping poison all round its body But with rabbit smells everywhere how does the snake keep tabs on his victim? Clever chemical technology has this covered too - the venom contains smelly marker chemicals and a diuretic.
So the dying rabbit dribbles a scent-trail of urine.
But the really clever part is still to come By the time the snake catches up with its newly dead victim, digestive enzymes in the venom have already got to work.
This rattler's venom is rich in cytotoxins, these digest the glue that holds the walls of the blood vessels together causing massive internal bleeding.
They then start to digest muscle tissue and the blood itself.
So by the time it's swallowed and begins to be digested from the outside, this meal will already have been pre-digested from the inside.
The result is a meal of tenderised meat.
Venom is the reptiles smartest offensive weapon but even smarter if used for defence as well The African savannah, can be a dangerous place for a snake.
This cobra has been spotted by a hawk In a fix, it has an amazing defensive trick it fires first! That's why this snake is known as the spitting cobra and it's so fast we can't see it in real time Its aim is guided by the architecture of its mouth.
Its fangs are fixed, with a rifled bore to focus the venom jet right on the target.
And the snake always aims for its opponent's eyes Spitting cobra venom is like acid - it causes excruciating pain And temporary blindness.
It's a unique and fantastically effective weapon the trademark of a truly smart reptile.
Deep in a forest in India, there's a creature that woodcutters fear above all others It's the giant king cobra, one of the longest, most venomous snakes in the world and when it rises up and spreads its hood, it can look a grown man in the eye.
One bite can deliver half a teaspoon of venom - enough to kill up to 13 people, or a large elephant.
Fortunately, it only rarely attacks people and then, only in self-defence.
The King cobra isn't interested in warm-blooded prey It specialises in much more dangerous quarry the Indian cobra.
This is a clash of reptile superpowers a war of chemical technology.
It's a lethal face-off.
These two opponents are so ludicrously over-armed, between them they carry enough poison to kill a whole platoon of soldiers.
The king cobra that strikes first Venom containing fast-acting neurotoxins immobilises it's dangerous victim.
But that's not all A neutralising agent in its Blood protects it from the bites of other snakes So the king cobra is immune! What brilliant biotechnology The king of the cobras is surely the ultimate smart snake So it seems all reptiles have amazing hidden, talents.
Their defensive techniques are extraordinary.
And they've developed sophisticated attack weapons.
Their senses are in many ways superior to ours And they communicate in ways that we can barely comprehend.
Surely we underestimate them at our peril! There's just one word that sums up reptiles amazing behaviour and biotechnology - - Smart!