Reptiles, mysterious, mythical, monstrous.
The name means things that creep, and that's just what they've done, crawling and slithering
into the corners of our imagination.
They look like creatures from fiction, but with reptiles, fact is far stranger than any
fiction.
Reptiles come in four families.
Lizards and snakes, fascinating and foreboding.
Turtles, slow and strong.
Crocodilians, monsters of the waterways.
And the one and only Tuatara, the living fossil.
What is a reptile?
All reptiles have scaly skin.
It's thick and watertight, like a raincoat in reverse, it keeps the water in.
Reptiles are cold-blooded.
They get their heat from basking in the sun, making them the original sun worshipers.
In effect, they're solar powered.
At the start of the day, all a reptile can do is just sit there, soaking up enough energy
to get moving.
But it's a very efficient design.
Since they get 80% of their energy from the sun, reptiles need far less energy to come
from food.
They can stay in one place, rather than chasing after the food like warm-blooded mammals.
And what if they get too hot?
Reptiles always find a way to cool down.
They might hide under the sand, or clamber into the shade of a convenient rock.
The crocodilian family gates just as dogs pant to release excess body heat.
And this creature goes into workout mode to stop the hot sand from burning its feet.
Reptiles come in all shapes and sizes.
There are lizards that are larger than a human, and others smaller than a beetle.
There are six and a half thousand different types of reptiles, each sculpted by the fine
art of adaptation to fit its environment perfectly.
Like the moloch, or thorny devil, a threatening, vicious monster, only on the outside.
It's a member of the largest reptile family, the lizards, and lives in the desert where
those spines do more than just deter predators.
They collect dew for the animal to drink.
Or the basilisk, named after a mythical medieval beast that could kill with a single look.
This animal is harmless, it's light and athletic, and has frills on its feet which help it literally
to walk on water.
That's why it's sometimes called the Jesus Christ lizard.
Geckos have adapted brilliantly.
Their feet are like suckers, covered in millions of tiny hairs that will grip almost anything
from any angle.
Of the four families of reptile, turtles are by far the slowest.
The top recorded speed for a giant tortoise is only 16 feet a minute.
But as in Aesop's fable of the hare and the tortoise, slow and steady often wins the race.
The turtle has a unique adaptation.
Its backbone has become a shell.
It's actually part of the animal's body.
And when that body belongs to a giant tortoise, that's a big, tough, and heavy shell.
It's so tough, and giant tortoises have such strong muscles, that if it would let you,
you could use one as a jack.
Yes, these creatures that can live for over a hundred years could support more than a
ton of metal.
Maybe that's why thousands of years ago, people in Asia Minor believed that the earth was
held up by a tortoise.
Sea turtles have adapted to the oceans wonderfully.
They can stay underwater for over three weeks at a time without taking a single breath.
That's something to try in your local pool.
But when they move, they really move, migrating thousands of miles.
One theory explaining these marathon migrations claims that millions of years ago, when turtles
evolved, the continents were much closer together.
Although they drifted apart over the millennia, turtles have instinctively returned to their
breeding grounds, no matter how far away they are.
It's not just great distances they travel, they can dive to great depths too, deeper
in fact than most modern submarines.
The reptile family closest to the sea dragons of myth are the crocodilians, embracing alligators,
caimans, and of course, crocodiles.
With their huge smiling jaws and watery eyes, they're as old as the dinosaurs and perfectly
adapted to life in the rivers.
Their tails are their motors, their feet are their rudders, their skin is an iron hull,
and when they move, they strike like lightning.
A fully grown crocodile can lie submerged for well over an hour waiting for prey.
When they make a kill, they can't chew, so they have to twist and literally tear the
meat off the carcass.
Vicious, deadly, certainly.
But these killer jaws can also gently cradle a baby.
Crocodilians are one of the few reptiles that look after their young, and with protection
like this, who would dare snatch a baby from the jaws of its mother?
In fact, it's the jaws that show the difference between a crocodile and an alligator.
An alligator has a more rounded snout, and its front teeth stick out.
Alligators are smaller, too, and are only found in China and America.
They were mistakenly named after the Spanish word for lizard, el lagarto.
Their appetites are smaller, too, unlike the largest crocodile, the saltwater, which will
eat almost anything, a two-ton giant named Sweetheart trying to eat more than twenty
outboard motors.
The people in Papua New Guinea believe the crocodile is the creator of all things.
Young men are swallowed up and regurgitated as adults.
Hence these teeth marks on their backs.
In their canoes are carved crocodiles carrying people, just as crocodilians carry their babies
on their backs.
But don't ignore this sign.
Would you really want to swim with a crocodile?
In fact, they're more at risk from us.
Maybe those fabled crocodile tears aren't so insincere after all.
The ancient Egyptians relied on the Nile for their lives.
It was the source of all their prosperity.
But swimming in the river of wealth was the crocodile, a deadly reminder that the gods
were still in charge.
So they worshiped crocodiles and gave Sobek, their god of fertility, the head of a crocodile.
The largest reptile family is made up of lizards and snakes.
Snakes evolved from lizards, appearing after millions of years of changing shape and losing
their legs.
A snake is long on length and short on width.
Its internal organs have been rearranged like carriages on a train.
Windpipe, heart, small left lung, long right lung, long liver, long stomach, long intestines,
long kidney, and holding it all in, a long, long spinal cord with rib cage.
The biggest snakes can have 400 vertebrae, each with its own pair of ribs.
And each of these helps with locomotion.
Some snakes seem to slither, but the Sidewinder truly has a style all its own.
It steps across the baking sand with only two parts of its body touching the ground
at any time.
Snakes don't just use their muscles to walk.
Many use them to squeeze their prey to death by constriction.
They do this by literally crushing their prey, tightening their hole with every breath the
victim takes, slowly but surely suffocating it.
They're so alien that snakes have a special place in mythology, from ancient Greece where
serpents were sent to kill Leakoun and his sons, to the fearsome snake pits of modern
adventure films.
But the classic image of Terra is the Greek Medusa, a gorgon with snakes for hair.
Even after she was decapitated by Perseus, just one look was still enough to turn anyone
to stone.
In the Bible, the snake is the symbol of evil, tempting Eve with the apple.
Even a snake's forked tongue seems to carry a threat, something Hollywood has given lip
service to in its movie monsters.
It's not real, of course, but it is great entertainment for lounge lizards everywhere.
What the tongue is doing isn't vicious or threatening at all.
It's just tasting the air, gathering information for a sensor in the roof of the mouth called
Jacobson's organ.
It's like smelling, but a lot more accurate.
Snakes can use their tongues to pinpoint prey and follow its trail however fast or slow
it is.
Lizards also use their tongues in various ways, like cleaning their eyes, very useful
as many don't have eyelids for blinking.
When it comes to tongues, chameleons can silence any challenge, for their tongues are like
an extra limb, longer than their body, and they can use them to catch prey.
They have eyes that move independently so that they can look in two directions at once.
If humans tried this, they'd just go cross-eyed.
For chameleon, it means 100% accurate tracking of prey, making the tongue the reptile equivalent
of a guided missile.
Perhaps what chameleons are most famous for is their ability to change color.
One chameleon can be any or all of these colors, but reptiles don't actually see color very
well.
They see movement.
A snake charmer's music isn't charming to the snake, it's too high-pitched for any
snake to hear.
The snake is really swaying to the movement of the pipe, it would strike if the pipe would
stay still.
Even without the pipe, the snake is still mesmerized by movement.
Reptiles wear coats of many colors, although they themselves can't see them.
Color is another form of adaptation, protection from birds and mammals that can see color
and prey on reptiles.
Color can serve as a reptile's first line of defense, provided it remains in its color-coordinated
natural habitat.
Camouflage works to conceal reptiles from their prey, helping them to make that vital
strike.
Sometimes it's better for all concerned if everyone knows who's who and what's where.
A rattlesnake rattles to say, don't tread on me, and packerys know better than to tangle
with a rattler.
When crocodilians roar their message, they can be as loud as an airplane.
A coral snake doesn't have to shout to be noticed.
Its color announces its deadly poison, red, yellow, and black are nature's primary warning
colors.
But some appearances can be deceptive.
This frilled lizard looks vicious and threatening, but it's all bluff.
Behind the skin and bone frill is a reptile far more likely to turn tail and run.
The armadillo lizard just puts its tail in its mouth, making it very difficult to eat.
Some tails are a bit too long for that though.
But when it comes to mating, however, reptiles display some of their most bizarre characteristics.
Plowshare tortoises jousting over a female resemble a pair of tanks, aggressive characters
coming out of their usual shells.
The outcome of all this is the greatest reptile adaptation of all.
Reptiles were the first animals to leave the water for good and stay on land, but they
only accomplished this giant leap by taking a bit of the water with them.
So wherever a reptile lived, however dry it was, it still had some water for its very
young babies, a drop of water and a bag of food.
And a casing with very tiny holes so air could get in without water leaking out.
We're talking about eggs.
Reptiles were the first animals to lay eggs with shells.
They invaded the land and could live anywhere, thanks to eggs.
But that doesn't mean growing up is easy for a young reptile far from it.
From the thousands of eggs laid here, only five males will survive to mate and five females
will live the 30 years it takes to mature and return to lay eggs of their own, because
these babies are easy prey.
On
a group of islands off New Zealand, the fourth and smallest reptile family, the Tuatara,
had few predators to contend with.
There are only three species of Tuatara and they bear the closest resemblance to ancient
reptiles.
Now, they're in danger of becoming extinct.
Because almost a thousand years ago, humans arrived, bringing animals that were new to
the islands, including predators that could invade Tuatara burrows and eat their eggs.
Most species adapt over millions of years to life with predators, not so with Tuataras.
So this living fossil, with a vestigial third eye on the top of its head to sense light
and a metabolism so slow it can go up to 60 minutes without breathing, is in danger of
breathing its last and vanishing from our world.
One animal that still hasn't appeared in New Zealand is the snake.
They've only been on the earth as long as the mammals and birds, almost as though they
evolved specifically to hunt them.
They certainly have a special technique for dealing with bird eggs.
The snake's jaws are expandable to fit the egg in.
There is a muscle to help swallow the egg.
There are special spikes on the inside of the spine to break the egg so the tasty contents
can be eaten and the crushed empty shell regurgitated.
Finally, the jaw is put back together with a lazy yawn.
Some snakes also have special heat-sensitive pits in their lips for detecting warm blood.
It's like seeing infrared and makes striking with those feared venomous fangs all the easier.
Fangs, the hypodermic needles of the reptile world.
In fact, less than a quarter of the world's snake species have venom that is harmful to
people.
Many of these are now milked for their poison to create anti-venom.
It's injected into horses, where immunity builds up in the blood which is then used
for serum against the snake bite.
Nevertheless, there are still 30,000 to 40,000 human deaths each year from snake bites.
One of the most venomous snakes of all is the sea snake.
This one isn't tying itself in knots.
It's rubbing against itself to shed or slough its skin.
Reptiles grow out of their skins, shedding it like a garment that no longer fits.
And because of a snake's shape, all it has to do when it changes skin is just crawl out
of the old one.
This leaves behind a ghostly double.
It looks as though the snake has been reborn, so snakes have become the symbol of eternity.
The Hindu god Vishnu lies in heaven in the coils of the eternal serpent.
The cobra is a symbol of fertility for Shiva and his wife Pavati.
The Australian aborigines believe that the mother and father of all creation, including
humans, is a snake.
In the West, the sign of Escolapius, the Greek god of medicine and the modern symbol of health
and healing, is a staff with a snake wound around it.
But reptiles can't be contained by myths and symbols.
They're larger than life.
The Komodo dragon, a real live dragon, is the largest lizard in the world.
It's 13 feet long, weighs 300 pounds, and is genuinely fierce.
Its saliva is toxic, so it can kill just by biting and then waiting for its prey to drop
exhausted from infected wounds.
But it usually feeds on animals that are already dead.
The alligator-snapping turtle, also the stuff of nightmares.
It can weigh as much as a grown man and eats anything it can get.
The alligator-snapper lies disguised on the river bed, mouth open, its worm-like tongue
luring unsuspecting prey.
In parts of Europe, they now lurk in ponds and streams.
Whatever gets too near is snapped, and that can be anything from a small fish to a human
hand.
The Chinese honored dragons as law-givers.
In the Manchu dynasty, everything used by the emperor was described in terms of a dragon.
They even believed a dragon introduced the art of painting to China.
The constellation Draco was named after a dragon hovering in the heavens.
Knights like St. George fought dragons in legend, hence their use as a symbol in heraldry.
European mythology cast dragons as evil, fire-breeding monsters that roamed the countryside, kidnapping
maidens and hoarding great treasures, perhaps because the early Christians were eager to
demonstrate their power over the natural world.
So legends came to show the very image of Christian virtue, like the German Siegfried
who slew the dragon and sought boundless power from its blood.
Now our attitudes towards nature have changed, but we still hear stories of superhuman struggles
against monstrous reptiles.
In the early 1900s, a reward of $1,000 was offered by the New York Zoological Society
for proof of a snake longer than 40 feet.
That's now worth $50,000 and still hasn't been claimed, because despite assertions to
the contrary, snakes don't grow that long.
The record so far is a reticulated python at 32 feet.
It's just another one of our projected images.
It's not humans that are most at risk from snakes.
Lizards live the nightmare that given the opportunity, a snake won't hesitate to make
a meal of its reptilian cousin.
The
Yet just when it seems all is lost, some reptiles
have one more twist, literally, to their tail.
Many lizards can shed their tail to evade capture.
It's a final resort, but it means safety.
It's just one more reason reptiles have survived so long.
One more adaptation.
One more way in which the truth about reptiles is stranger than the myth.
The
eyewitness museum, created by combining traditional filmmaking techniques with state-of-the-art
graphics, stripping away the mysteries of nature and science, to reveal the essence
of each subject, bringing the world into sharp focus.
The making of eyewitness.
The distinct style of the eyewitness books is the basis for each of the programmes.
Each half-hour episode is based on a book title.
The eyewitness book's visual style gives the programme makers a starting point and
a challenge.
The challenge of transferring the clarity and super-realism into moving images and sound.
Now let's take a look behind the scenes at the making of reptile.
The eyewitness museum was developed to house a wide range of subjects under one electronically
generated roof.
We started with the architecture.
With an electronic building, staircases and elevators are not needed.
Just the most exciting route.
The objects in the museum also needed to be built.
Once programmed into the computer, the plane is as good as real and can be lit and viewed
from any angle.
The final choice rests with the designer.
The museum can show us the distant past.
Into a computer, a dinosaur is as real as the aeroplane.
The computer can give us an exciting building and models, but more is needed.
Real animals.
Incorporating live action into the museum was the biggest challenge.
Just building the underwater room took weeks and combined several layers of film, graphics,
effects and specially shot fish.
The final element for the title sequence was the music.
With so many varied rooms and animals the brief was complex.
The music is our only guide to the museum in this sequence, both in terms of movement
and location.
For every visual move and piece of action, a synchronized music cue was needed.
As well as providing a musical theme for the whole series and the eyewitness motif.
One of the memorable images from Reptile was the car apparently jacked up by a giant tortoise.
Convincing though it looks, the car was not actually held up by the animal, but by a breakdown
truck.
By tickling the tortoise's neck, our specialist handler encouraged it to lift up its shell.
A movement used a great effect in the final cut.
How did some lizards evolve into snakes?
In the eyewitness museum's x-ray room, this was graphically illustrated with the use
of 3D computer animation.
By plotting the changes on a computer, millions of years of evolution were shown in a matter
of seconds.
We used another electronic process to tell a shorter story.
This time it wasn't really the snake who removed the lizard's tail, but an image manipulation
computer called Howl.