Inside Nature's Giants (2009) s02e02 Episode Script
Monster Python
There's an alien invasion going on right here in the Florida Everglades.
Burmese pythons, some of them over 5m long, have escaped into these swamps.
By dissecting the body of one of them, we're going to find out how they kill and consume such huge prey.
And we'll investigate why such a bizarre shaped body has allowed snakes to conquer virtually every corner of our planet.
Join us as we go deep inside the giant python.
The vast wetlands of Southern Florida have become home to a foreign predator.
Back now at 7.
50 with a scary population boom in one part of Florida .
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officially out of control and spreading.
Burmese Pythons, imported from Asia as pets, are now on the loose here.
No-one knows exactly how the pythons got to the swamps.
One theory is that some escaped from reptile breeding centres damaged in Hurricane Andrew in 1992.
But biologists think pet owners dumping unwanted snakes are a more likely source.
Here we have an invasive organism that's very effective at eating all the species we're trying to restore.
In an attempt to control numbers, locals are being trained to capture and kill any pythons they see.
The cull offers us a rare opportunity.
I've come to Florida with anatomist Joy Reidenberg and biologist Simon Watt to join the hunt for the pythons.
We want to find a giant snake and dissect it so we can reveal the inner workings of a truly remarkable animal.
THUNDER They call this the Sunshine State.
I think they're being very, very optimistic.
But more seriously, it's also the lightning capital of the world and we happen to be out in the middle of it in ametalboat.
To ensure we get the biggest possible python, our plan is to split up and see who can find the best specimen.
What have you done to the weather, man? I didn't ask for it! 'My money is on snake expert and former marine Jeff Fobb.
' Go find some snakes! You reckon you can find snakes even in this weather? It's possible.
The ideal way to find one would be as it's crossing the path, when it's in the open.
That is the easiest way to find them.
Their camouflage is excellent.
And what's the biggest you've found here? The biggest one I've ever caught is 14ft! That's a big snake.
Yeah, that's a fairly big snake.
I tell you what, I'll take a look down the other side if you take that side.
So where you coming from, you say? Oh, I'm from Northern Ireland.
We've got no snakes there, Saint Patrick took them all out.
Oh, no snakes? Rather than trek through swamps, I've come downtown to let the snakes come to me.
This unassuming fire station is home to America's leading snakebite response team.
If someone in Miami comes across a nasty-looking snake, these guys are there within minutes.
Come on in.
This is our little corner of the world.
We have our anti-venom bank.
All of this? That's all anti-venom.
95% of what's venomous and can kill you, we have anti-venom for.
Are you finding you're dealing with more constrictors nowadays? More and more constrictors, yeah.
Three years ago we caught 20, two years ago we caught 40, and last year we caught 89.
So it's getting higher and higher now.
If we get one in the Miami area, it'll be here.
This is the place to be.
do we just have to wait around? Grab a chair, we'll just hang out and wait.
The minute I see one, everything just goes - pff - out of my brain and I jump on it.
Joy has come to a Python hot spot in the southern Everglades to search for snakes with seasoned python hunter Joe Wasilewski.
You're going to try and head it off at the pass? Yup.
And bring it out here? I'm going to drag it out here, probably grab it by the tail, if I can.
Once we have it in the open, once we have that thing focused on trying to biteus and not get away You, not me.
No, no, no, no, we're in this together! All right, you have to tell me what I'm supposed to do.
OK.
Cos I'm a afraid that this thing's going to bite.
How dangerous is that? Is this a serious bite? It hurts, trust me.
Depending on how big, they could cause some damage.
But they're not venomous, so they're not going to kill you and that's good news.
Why are you taking me through the water, when we should be looking for them on land? In many cases, they'll take refuge in the water and that actually is one of the times when it gets a bitscary.
All these little dots represent large constrictor reports or recoveries in Miami-Dade County.
All the red dots, those are all Burmese pythons.
The snakes are out here too, but there's nobody there to find them, cos there's no roads, so people don't see 'em.
PHONE RINGS Venom Response.
Lieutenant Wood, may I help you? OK OK.
What colour is he? OK.
And your address is? OK, um, just sit tight and keep an eye on it and we'll get there as soon as we can, OK? All right, thank you, bye-bye.
Have we got one? OK, we got one, it's a snake in a bank.
This should be interesting.
And realistically, if you'd told me even five years ago that I'd be out here looking for pythons, I would have told you you're crazy.
That's how new this Oh, shit! I got him! Here, wait You got it? Yeah, I told you they're fast.
My God, that's huge.
Wait, grab the tail there, let's just Wait, wait, wait, pull it out, keep pulling, let's get the head towards me.
Hold on, wait, don't OK.
Whoa, look at that! Oh, shoot.
Oh, my gosh.
OK No, that's not big, that's a small one.
Actually, feel the power.
I am, I'm making sure it doesn't wrap around me.
Grab it right there, you can feel the two bones right there? Yes, that's the back of the jaw? Yes.
If you keep your hand there, cos they can actually, how can you say, kind of turn their heads.
You got it? Got it.
Got it.
All right.
I'm amazed you saw it.
I just saw it move.
Two more seconds and this thing was in the bush.
We might have found it, but I don't think so.
OK, let's just relax a second here, just take a deep breath.
It seems to be pretty calm now.
OK, so bagging it is another Not problem, because we don't have any problems, but an issue.
OK.
Let's switch again, I got it.
OK.
Take the middle coil, like right there and put it in the bag.
There you go.
He wants a piece of me.
See, if I let him go now, he's going to cut me.
Wait, wait, wait.
Oh, look at him turn.
Whoa.
Yeah.
Right, one, two, three.
Phew! High five? Yes! Where is he? Where is he? Right over here.
We saw him so we wanted to keep him under here.
Oh, good job, excellent.
Oh, he's tiny! Yeah, yeah.
We're slightly disappointed.
No, so was I.
I heard a snake They're looking for big pythons.
No, sorry.
You want to retrieve him? What do I do? How do I get one of these? Just reach under there and get him.
Yeah, but do I have to have some lightning-quick reactions or something? No.
Ah, there you go.
Here, boy.
Yeah, I've got him.
I mean he might bite you, but it's so tiny.
Oh, he's so, so tiny this little fellow.
I can see he's bright orange underneath, is this a defence signal perhaps? Mm-hmm, that's a defence signal.
So he's scared of me, pretty much? Oh, yeah.
This is our first catch of the day.
Next stop, Burmese pythons, with any luck.
By the end of a long and soggy search, I'd failed to see a single snake.
Surely I can bag something bigger than the snake in the bank! 'The fire department took me 'to a snake breeder who lost several pythons in a warehouse fire in 2007.
' Where is it? In the freezer, help yourself.
(LAUGHS) That's enormous.
That's one of my big females, I lost her in the fire.
She's huge.
a use for the dissection, you're more than welcome to it.
Thank you, this is perfect, this is just enormous.
The fun part is getting her out.
Would you mind giving me a hand? Yeah, I think we'll need it.
OK.
OK, I'll take the top half.
Holy cow.
How do you? Whoa.
Now we've got her, there we go.
'Now, surely this has to be the winner.
' Now where? Yes, no? Yes, yes.
OK, good, good.
Wait till you see this baby.
'With our python hunt over, it's time to compare catches 'and select a snake for dissection.
' Yes, no, maybe? Oh, yeah, and it's huge, quite frankly.
Huge? What about you guys, any luck? Me, no, but Joy's got one.
Oh, wow, that is very heavy.
That's really heavy.
Isn't that a beauty? That's a lovely snake.
Let's get her straight, if we can.
OK.
It's quite pretty, huh? Let's just get this one out in comparison.
Oh, my God! Oh, my God, that is massive.
I did tell you.
Whoa, you'd need six people to carry this guy.
That is absolutely huge.
He's enormous, isn't he? Should we just take him the same way, so we've got the head the same end? Stick the heads side by side.
OK, that is a very big snake.
Oh, my God, look how big this is.
That is a huge, huge snake.
Wow.
I didn't realise they got this big.
I thought mine was a big snake when I saw it! Two, three I mean, that's four metres.
Is it really soft and mushy? Is it really soft and mushy? Yeah, very.
Oh, yeah, it's really mushy here.
I haven't felt it since it thawed, actually.
OK, we've got Jeanette from Florida Atlantic University.
She's the reptile anatomist, she's looking after the science of these dissections.
Your first impressions about these two? This is a whopper.
It is a whopper.
This big bodied snake is probably a female.
But it's kind of lumpy-looking and This one died in a fire? A fire and been in a freezer for? For nearly three years.
Oh, wow.
So from an anatomy and a dissection point of view, is this going to be a suitable candidate? It's a great snake in terms of its size, but It's got great size, but boy is it? The viscera are probably pretty, pretty decomposed.
I would say this is going to be not that useful an animal for anatomy.
This one, on the other hand, is really firm still and, you know, when I reach underneath, you know, it keeps its shape.
So, ah, let's work with this one.
I have another one over here that's from the park, so And how big is that one? A little bit bigger than this.
We'll lay them out and make the comparison.
We'll pack these up, take them to where we'll do the dissection and compare the two and crack on.
From the outside, snakes may look like simple animals, but under the skin lies a remarkable story of survival.
Snakes have adapted to thrive in almost every environment on Earth.
Their muscles move their bodies with mesmerising ease.
They've evolved anatomy to sense, squeeze and strike their prey before they swallow it whole.
Their ability to wait months for food makes them master ambush predators.
As scientists, we want to show you the inner workings of the snake and explore how this extraordinary animal evolved.
We're carrying out our dissection in what is a truly amazing location.
It's a swamp-camp right in the middle of the Everglades, where all the action is taking place with the Burmese pythons.
Our team are just doing some basic measuring and weighing.
And for me, the most incredible thing about these giant snakes is not just, for this female, how big it is, but just look at this body.
It is one massive tube with a head at the end.
We are so familiar with our own limbs.
That's how we get around, that's how mammals get around.
And yet this is an animal that is incredibly agile.
It gets all over the place, yet it does is with just a tube.
But these animals are able to use a couple of different ways of getting around.
One of them is, what we would call, "sinusoidal locomotion".
So you'll see this snake putting its body into these S-shaped curves.
It's anchoring in one part and pushing the body forward with another part.
That's the kind of classic snake slithering that everybody, if you asked a child to draw a picture of a snake moving, that's what you'd get.
Exactly.
It's this S-shaped curve that just keeps going by.
And that's actually a bit hard for a real heavy-bodied snake, like this female.
A lot of times you'll see these snakes look like they're just moving forward, in a straight line.
And it's a little bit eerie, but it's remarkable.
When we turn the snake up, you'll see that it's got these scales on the bottom.
And each has a set of muscles attached to ribs.
You're now really starting to whet my appetite.
I want to see under here and see these muscles.
OK, so where should we cut? Let me get it started, here.
So we're seeing these muscles here.
All these white ones running diagonally.
They're going into the skin and they're going to lift the scales forward.
Underneath them is second layer.
It's going in the opposite direction from this layer over here.
But the real power is actually coming from these muscles, which are right on the bottom.
The graceful glide of a large python requires intricate coordination of muscles.
As a section of the belly muscle relaxes, rib muscles pull it forwards.
A contraction then drags the belly along, and a second set of rib muscles keep the top of the snake in synch.
The pattern is repeated along the body to produce a steady, forward motion.
My brief is to get as close as possible to the animals.
And here, in Florida, that's not difficult.
Round here, an encounter with a python is quite common.
Their agile bodies take them almost anywhere.
Pythons like this are so at home in the water.
You can see it glide through, beautifully, using that same S-shaped motion that is uses whenever it's on the land.
It's beautiful to watch.
In their home ranges pythons like this live very close to water.
They're so used to it, they use it for thermo-regulating - controlling their body temperature.
They use it as a way of hunting.
They use it as a way of getting from A to B.
Here in the Everglades, pythons like this have been shown to travel up to 70km during the wet season.
It's astounding! OK.
So we've been working on taking the skin off of this python.
And when we peel it back here, what we see is a very beautiful structure.
If you pull the skin, you can stretch it and recoil it back and forth.
So you see how the scales overlap over each other, almost like a little accordion.
The reason they do that, is there's skin underneath these scales.
So that allows some stretch in here, which is really important because not only does the python have to curve its body, moving through the ground or even swimming, but it also has to be able to stretch its belly when it swallows something big.
Imagine how much can this skin stretch around? Well, it can almost eat me.
Not quite but, you know, maybe if I lost a little weight! A python that was a little bit bigger could probably swallow me because it's really, really stretchy.
Very stretchy skin.
To show us how snakes curve and contort their bodies, Jeanette has prepared the spinal column of another large python.
Wow! That is amazing! Compared to the 33 vertebrae of a human spine, this is truly impressive.
This is hundreds! This snake probably has somewhere around 300 vertebrae.
They just get bigger? From birth.
That's right.
So if we were to go and look at each one of these, what you would find is, when you get that curve, it's really from a whole bunch of vertebrae bending, not so much a sharp bend in any one.
And yet what you're not seeing is any sense of limbs here.
So does this come first and then, in evolutionary terms, and then limbs are somehow kind of attached for a different form of locomotion, or is it the other way around? You've asked a really old question, a really important question.
So one of the things that we can show you is the evidence that these snakes are derived from lizards.
It's easiest to see these things in the male.
And so I'm going to turn this over and you'll see these structures on both sides.
These are called spurs and the males use them in reproduction and courtship.
And what I'm doing here is just simply separating out the muscle from the body wall.
Grab that with the forceps there.
That's muscle, and here we have Oh, look at that.
Look at the bone coming out now.
This is amazing.
Pull this back.
And there we go.
That's the limb.
This is the equivalent of pelvis.
Equivalent of the pelvis.
That's the equivalent of the thigh bone, or femur, and this part on the end is like a fingernail? Probably.
That would be a good description.
So they skip right over the leg.
So it's, so it's like It's like that.
Exactly.
That is amazing.
Evidence.
Evidence of evolution.
That That is incredible.
This vestigial leg, now nothing more than a claw, is evidence that the ancestors of this creature once ran along on legs.
Imagine you had an ancestor a bit like a lizard, with a, sort of, lizard number of vertebrae.
And then in evolution, the vertebrae got duplicated and duplicated and duplicated again.
It's like a goods train and just putting in more and more trucks in the middle.
They're nearly all thoracic vertebrae from the chest.
They lost the front limbs and the hind limbs.
And amazingly, there are vestiges of the hind limbs still there.
It's a very telling example of a vestigial organ.
Something that was once there and was once larger and has now almost completely disappeared, but betrays its history by being still there in a reduced, modified form.
Serpents have been synonymous with evil since the Garden of Eden.
We have long been wary of their forked tongue and slithering movements.
When pythons appeared in the Everglades, there was another reason to demonise them.
Over its lifetime, a python consumes hundreds of prey animals.
Florida's native species were under threat.
'Researcher Clay DeGaynor discovered the first python' A field project, radio-tracking one of the rarest species on Earth - the Key Largo woodrat - came to an unfortunate end.
The rat was found inside an eight-foot-python.
This is what happens when a near-perfect predator is let loose in a fragile ecosystem.
The python's hard wired to hunt.
It has no evil intent.
As for the menacing forked tongue, it is best understood as part of the snake's sophisticated senses.
Snakes, as you might see very quickly, they don't have any eyelids.
Or they appear not to have any eyelids.
In fact, what they have is an eyelid that has fused and covered the eye itself.
And that fused eyelid becomes clear and it's called the spectacle, and the spec But it's actually a scale of the skin.
No, it's actually the eyelid.
It's shed when they shed their skin? It's shed when they shed their skin.
Now, these animals do have a nose, but probably they're not actually smelling with the nose.
They're probably smelling, from what we know about snakes, with the tongue.
By waving their tongue in the air, they're picking up chemicals, just like we pick them up with our nose.
If the tongue were to come out and touch the environment and then go back in, it would be placed back up there, that's called the Jacobson's organ, or the vomeronasal organ.
In essence, that's their chemosensory area.
So let's just cut that off, so we can take a look at the tongue itself.
Thank you.
OK.
If we lay this tongue out, we notice that at the tip of the tongue, it's actually forked, so it has two prongs, a left and a right.
This is going to enable the snake to pick up chemicals on both sides, both the left and the right prongs of that tongue, and compare the left to the right side.
As soon as it knows which side it has a stronger scent on, that's the direction it's going to go.
Another really amazing thing that pythons have, is the ability to see an image with infra-red.
And infra-red is associated with heat.
And so the animals actually have a set of clefts that are their infra-red detectors.
It's almost like having an in-built thermal-imaging camera.
They're going to see the heat.
If they've got a prey animal, say here, they may not be able to visually see it, but they'll be able to sense the temperature of that animal compared to its surroundings, which says this is potential prey.
Python vision is poor and they don't have ears to hear sounds.
But make no mistake, other senses are finely tuned for night-time hunting.
They can feel even the tiniest vibrations in the ground.
Their constantly flicking tongue picks up the chemical scent of prey.
And their infrared sensors lock onto the target.
Even in complete darkness, nocturnal snakes strike with near-perfect accuracy.
These pythons in Australia are able to pluck bats out of the air.
And this mouse may think it's free to forage under the cover of the darkness, but the rattlesnake knows exactly where it is.
The venom kills it in seconds.
Hey, Tom.
Pleased to meet you.
Hi,Tom Crutchfield.
Pleasure to meet you.
Pleased to meet you If you want to know your boas from your anacondas, or your mambas from your vipers, Tom Crutchfield is your man.
We'll go into the Venomous Room first In snake breeding circles, Tom is a giant.
His Florida-based collection of rare and exotic species is world-renowned.
You first.
Just watch your step.
A visit to his Venomous Room is not for the faint-hearted.
Here's an example of the most dangerous North American rattlesnake - the Mojave rattlesnake.
It only takes about 15mg of venom to be lethal for an average 160lb man.
It would take a little more than that for me, weighing a little more than 160lb.
This is a large albino cobra, which is captive raised.
This is from South East Asia.
This particular one is SNAKE HISSES .
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from Thailand.
This snake probably causes more deaths in South East Asia than any other snake.
He's sitting up about a foot or so, and that's about as far as he can strike.
We don't have to run.
You can just tell this thing's angry It's not angry at all? It's not? It's not? It's afraid.
It's afraid? It's afraid.
I mean, what would you do if a giant had you? Now, he's going to turn and he's going to try to bite me.
That was a pretty good attempt.
So, all these snakes kill their prey and would-be attackers using fangs and venom.
But I want to see some snakes with a much more brutal approach.
Some constrictors.
You got any of those? Some constrictors.
You got any of those? We do.
We have constrictors.
OK.
Now, on this one, what you're going to have to do is put your hand down and when you get it, you're going to have to get it behind the neck.
You can't hesitate.
I don't want you to do this sort of thing because he'll see that and he may strike at you.
If he does that, he may bite you.
You have to put your hand down, without hesitation, and grab it behind the neck.
Do you feel ready to do this? Um, yeah.
The worst thing that can happen is you're going to bleed a lot.
I'm not going to let it do much to you.
All right, OK, let's go.
Nervous, but ready.
The head is right here.
Come on this side.
See, it's looking at you.
Don't, don't Go ahead, grab it behind the neck.
Get it out quick.
Now, you can see here Oh, he's already trying to coil me.
He's gone for my arm.
In fact The longer you hold him, the more pressure he'll put.
And he's probably already, he's already cutting the blood completely off, to your hand.
Imagine a much bigger snake wrapped around you.
Every time you exhale, it will squeeze tighter and you can't breathe.
You still, you don't die from lack of oxygen.
What you die of, is your heart stops because that steady, consistent, hard pressure, within less than a minute, your heart stops and you die.
Can you feel the pressure? Look at your hand now, the colour.
This, this snake is piling on the pressure and this is what it does in defence, or in attack.
This is really it's weapon.
And snakes like this have been doing this for a 100 million years.
This is a technique which worked and it's stuck with it.
Look at how his hand looks.
It's literally purple.
It's beginning to hurt now? It's beginning to hurt now? You can feel It's even trying to coil around my back.
I think it wants to finish me off! This thing's going for it now.
Do you mind taking it off? I can take it.
Patty, can you help? She's going to have to unwrap it from the other side.
Hang on.
Turn it loose.
I got it.
Turn loose the head.
Yep.
Oh! Ah.
Ooh! Let's put him back in the box.
It wasn't really trying.
What really is scary to me is, when you look inside this, it kind of reminds me of that movie Alien, you've got another set of mouth inside the mouth.
Look at this, there's a row of teeth here, and then there's also another row inside that, look at this one here.
So there's two rows of teeth.
And they're curving backwards, which is absolutely amazing.
If you actually have an animal that gets bit by one of these teeth, it's instinct's going to be to pull away, but because the teeth are curving inward, that's actually going to drive the tooth further into the animal and really secure and anchor that tooth into it, so it doesn't get away.
What I need to get my head round is how they can actually swallow a prey animal that is many times the size of their own head, because if I jack my mouth open and go, "Ahh", I can get a large burger in there maybe, that's about it.
But nothing bigger than that.
How does it manage to end up with a head that size, being able to take in something that's this kind of size OK, while our head is very fixed, a snake's head is very mobile, in many, many places.
In a human, the lower jaw's just one bone and it just articulates, right with the base of the skull.
But in snakes, they actually have a very complicated lower jaw.
It has another intermediate bone that connects the lower jaw to the skull.
It's called the quadrate bone, you can see it being moved right now, right in here.
The quadrate bone acts as a double hinge, allowing the mouth to open to an astonishing angle.
Unlike in humans, the left and right sides of the jaws are completely separate.
Each is free to move as the mouth splays even wider.
An extra set of upper teeth move back and forth as the snake walks its jaws along its prey.
With the teeth leading the way, the python pulls its body over its meal.
But with a mouth and throat full of fur, how does it breathe? This is the beginning of their breathing passageway.
This is normally going to be locked up into the roof of the mouth like that, to create a passageway from the nose down to the trachea and then to the lungs.
They're normally nose breathers? That's the normal, yeah, that would be the normal at rest position.
But if you've got something big in your mouth, that's going to separate this and block it.
So what these animals would do is actually extend this forward, so If you can grab this If I There you go, you've got that opening there.
It's almost like having a snorkel you can stick out the front of your mouth to breathe.
Not only can they stick this out, but the cartilage gives this windpipe some support, so it's not totally crushed flat, there's still an ability to breathe.
I'm loving this animal.
It's just amazing.
Hey! Yeah, so now he's coiling around it.
He thinks it's a live rat, of course.
He has not been eating for three or four months, so he is really, really hungry.
Given the chance, pythons will consume meals as large as their own body.
But if food is scarce they can last for months on nothing at all.
I've come to a basement lab in Denmark where professor Tobias Wang studies how pythons cope with this diet of extremes.
So you can see the entire snake here.
The rat is lying here, in the stomach now, just a few hours after ingesting.
You can actually see the jaws of the rat, you can see the spine.
Ok, here we have the snake one and a half days after eating the rat.
You can now see that the rat is gradually disappearing.
The head is no longer recognisable, we can't see the forelimbs.
So within the next day or two, this rat will disappear completely The CT scans show how large quantities of stomach acid break down every last bit of the prey.
In order to absorb nutrients from large meals, the intestines undergo a remarkable transformation.
Here we have the snake that is fasting, and here it is 24 hours after eating the rat.
What you can see here is the fasting animal has a very small, small intestine.
But we then look at the animal 24 hours after eating the rat, so the rat is in the stomach, but look at the small intestine, enormous increase.
In the hours before food arrives from the stomach, the python's intestine swells to an incredible size.
But a big intestine takes energy, so between meals it shrinks down and switches off.
So it's perfectly adapted to feasting, and it's perfectly adapted to famine? Exactly.
Gosh, look at the size of this! This is oesophagus, I mean, this is stomach? This is stomach, and look at the size of that intestine.
It doesn't feel like there's anything in there but oh, wait, wait what are these? Is this all fat? We're going to need to open this animal up.
There's a lot of fat and some of this Oh, look what we got here.
Cool! The ovary! Look at that! So this snake was getting ready to breed.
They basically start off with little tiny follicles, oh, man look at the oviduct, wow! Anyway So each one of these is a potential new snake? But it's the very start of it, it's the yolk and the egg inside it that then has to get swallowed by this little tube called the oviduct.
And its like a production line for producing new snakes.
This hole that Joy has her finger into now, is an open-ended tube.
That tube has to swallow each of these one by one and it essentially feeds the tube over the yolk, and it flows then down this tube here.
So, so delicate.
It's then fertilized by the male sperm that's come up the oviduct from reproduction, to produce one of these.
And it's this that then carries on moving down the oviduct and then be laid out through the cloaca.
But there will be a whole chain of these coming.
There's about 20 eggs there, so all those will come down the same production line.
And when they come out, they then all get stuck together and you have a clutch of eggs.
But a clutch of many more than that.
This is just one side.
We can see on the other side If we flip that out the way.
.
.
there's another ovary.
You'll notice that they're staggered, one in front of the other, so this other ovary is all the way up here.
These structures right here look very much like what we would call, corpora albicans, which is the scar from previous matings and previous years.
So if you actually counted up all the scars and these eggs, you've got an indication of the number of offspring this female's produced, which could be a very big number? Yes, it could.
Back in 2006, Everglades biologists found their first python nest.
It confirmed their worst fears.
The pythons were breeding.
In their native habitat python hatchlings are eaten by birds and jackals.
Here in Florida they have few predators.
Alligators will attack them, but they're not part of their natural diet.
Surprisingly, pythons will sometimes eat alligators too .
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although this one proved too much to stomach.
The python's only effective predator is us.
We're going to allow hunters, in hunting season, if they come across a python, they're going to have the legal right to shoot them.
But taking on giant snakes is not a task that should be taken lightly.
What else have we got here then? We do have the longest of all living snakes, and the only snake that occasionally kills and eats people.
And that is the reticulated python of south-east Asia.
OK, help me get it out, guys.
OK, just keep pulling it out.
Oh, he's heavy.
Woah, woah, woah.
You got it? Yeah, yeah, just got a hold of him, just about.
This thing's huge, isn't it? This is only medium sized as well? This is a medium sized.
So they get a lot bigger than this? Yep.
I once sold a snake to a Mr Lou Daddano of Serpent City.
It was a wild caught, about a 23 or 24-foot reticulated python.
He went in the cage with it, with one other helper, and I'd already advised him actually not to do that, at least to have two or three people.
And somehow the snake mistook him for prey, it bit him, constricted him.
His friend began stabbing it with a knife, which didn't work.
His friend then got, er, panicked and ran off.
The snake constricted him and actually killed him, he was clinically dead.
Fire Rescue got there and they used the defibrillators, like they use on human hearts to start them.
They shocked the snake, the snake released Lou and then to start Lou's heart again, because basically he was dead, they used the defibrillators and brought him back to life.
He was on the Oprah Winfrey Show.
Crikey, he got a lucky getaway.
He was an extremely lucky man.
You feel comfortable enough to hold the head? I'd love to give it a shot, if that would be all right.
I want you to put both hands around its neck, tightly, yes.
Tightly.
Yeah, this Now, this really gives you more of an idea, now you're understanding the power of this thing.
This guy's getting a bit fed up of being handled, we should put him back in.
Let's do that.
Let's do this, guys.
I want one of you to undo the front of the cage.
Go do that, Alex, open the front of the cage there.
Whoa, guys, somebody's got to help me here! It is getting seriously hard to handle at this point.
Where are we taking him? Putting him in here.
Into the big cage? OK.
Yeah, now we got to go round and close the back though.
There he is, he's happy.
This is an example of it's more afraid of us than we are of it.
It's just wanting to get away.
Yes, all that was simply to try to protect itself.
A snake like that is not a snake any one person should ever try to handle alone.
The dissection's getting to a fascinating stage now, because the team have taken all the internal organs out.
What you're left with is this fantastic impression of what a snake is.
It's a backbone, with ribs on the sides, and muscles that create this kind of gutter, if you like, that goes all the way down the body, right to the tail.
But laid in the gutter is everything that Joy and the team have laid out on the other side of the table.
And you've got pretty much every part of a snake.
The internal workings of a snake all laid out in a row here.
Jeanette, you've got the heart out? That is absolutely stunning.
And like so much of the snake, it's an elongated structure.
And no diaphragm, so we've got liver right next to lungs and right next to heart.
And here, two kidneys.
And look how it's all squiggled up, very unlike our kidneys that are kind of like a big bean.
And then this massive fat store.
Yeah, this is amazing.
Who would think that in such hot weather a snake would need so much fat? This is fat for energy stores to make this.
'Joy has noticed something strange about the lungs, 'and wants to fill them with water to take a closer look.
' It's going, it's going, can you see it move down there? You got it, there it goes.
There it goes, see that? Look at this.
This one's filled, this is the shorter lung, this is the left lung.
And this is the right lung, going all the way down to here.
I wouldn't have expected this kind of asymmetry, these lungs are two completely different lengths.
For whatever reason, maybe because it enabled them to wrap themselves around bigger prey, snakes became longer and longer and longer.
And, as so often in evolution, that had secondary consequences, that raised new problems.
And in particular, how do you pack all the internal organs into this long, thin tube? In the case of the lungs, snakes did something rather interesting.
The right lung stretches way, way down the body.
But the left lung is tiny, and in some snakes the left lung disappears altogether.
In the case of the kidneys and ovaries it's similar, but in this case the organs are just staggered, one of them is in front of the other.
It's an answer to the problem of how you pack the organs into this very long, very narrow tube.
I've got That's ovary, you don't want that.
GI contents lower 'Our dissection team's final task is perhaps the most important.
'We must search the python's gut to find out 'what species it has been eating.
' Wow, she really hasn't eaten much recently.
But look! There's a tooth.
A little something.
There's a tooth That needs to be in the bag.
They'll want to look at that under a microscope.
Yeah, right.
OK, we're getting some lumpy things here.
What is that? Now should I pour some water on this, or do you want to take it? What is that? What is that? Shall Iclean? Yeah.
Yeah.
Is that a hoof? That's hoof.
Are you sure? Are you sure? That's a hoof.
Are you sure? No, no, no, no, no, no, no.
Hang on.
Oh, no it's not.
It's a No, it's a bird.
That is definitely hoof.
Look.
Look.
This is absolutely amazing because when you clean this off, it is really obvious that this is one hoof from a small ungulate, so that's a, em, a two-clawed animal.
There's hair here as well, isn't there? Yeah.
Look at how long this fur is, too.
So this, this was quite a big animal.
I mean, standing on here like that, This would have been animal, I guess, would have been this kind of size probably, up to its head.
Wow.
We do get, we have feral pigs.
We have small deer, we have feral goats.
That's not pig.
That's definitely either deer or possibly goat.
Probably more likely deer.
Look at that! I've never seen this many sticks in a snake.
Now that must have been in the stomach.
Of the animal it was eating.
Of the animal it was eating.
.
.
of the animal it's eaten.
Surely it wouldn't have? It certainly wouldn't eat it on purpose.
That's amazing! It is astonishing, isn't it? It's the last bit of our dissection.
Finding that hoof is the kind of proof you need.
Here is an animal that is able to take huge prey, many times bigger than the size of its head, swallow it whole and then have such an efficient digestive system, it can digest every part of it apart from a little bit of fur and one toenail.
That is extraordinary.
The toenail belonged to a white-tailed deer, just one of the many animals on the menu as the pythons conquer the Everglades.
It's an odd story that these animals, snakes, with their immense length, their loss of limbs, should be so successful and yet they are.
They're in every continent of the world except Antarctica and perhaps it's a lesson in how successful animals can be if they take what looks like a disadvantage and turn it into an advantage.
There's one final twist to the Everglades story.
(NEWS REPORTER) 'The Sunshine State gets a blast of cold air' January 2010 brought the coldest weather Florida has seen in decades.
No-one knows how many pythons died in the freeze, but biologists fear the worst.
It will take more than a cold snap to halt this remarkable animal's invasion of Florida.
Next week we'll be dissecting a lion and a tiger.
We'll find out if they're the same animal under different skins.
This is a killing machine.
This is the business end.
And solve the mystery of how they roar.
All right.
Here we go.
This has never been done before.
ROAR Red Bee Media Ltd
Burmese pythons, some of them over 5m long, have escaped into these swamps.
By dissecting the body of one of them, we're going to find out how they kill and consume such huge prey.
And we'll investigate why such a bizarre shaped body has allowed snakes to conquer virtually every corner of our planet.
Join us as we go deep inside the giant python.
The vast wetlands of Southern Florida have become home to a foreign predator.
Back now at 7.
50 with a scary population boom in one part of Florida .
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officially out of control and spreading.
Burmese Pythons, imported from Asia as pets, are now on the loose here.
No-one knows exactly how the pythons got to the swamps.
One theory is that some escaped from reptile breeding centres damaged in Hurricane Andrew in 1992.
But biologists think pet owners dumping unwanted snakes are a more likely source.
Here we have an invasive organism that's very effective at eating all the species we're trying to restore.
In an attempt to control numbers, locals are being trained to capture and kill any pythons they see.
The cull offers us a rare opportunity.
I've come to Florida with anatomist Joy Reidenberg and biologist Simon Watt to join the hunt for the pythons.
We want to find a giant snake and dissect it so we can reveal the inner workings of a truly remarkable animal.
THUNDER They call this the Sunshine State.
I think they're being very, very optimistic.
But more seriously, it's also the lightning capital of the world and we happen to be out in the middle of it in ametalboat.
To ensure we get the biggest possible python, our plan is to split up and see who can find the best specimen.
What have you done to the weather, man? I didn't ask for it! 'My money is on snake expert and former marine Jeff Fobb.
' Go find some snakes! You reckon you can find snakes even in this weather? It's possible.
The ideal way to find one would be as it's crossing the path, when it's in the open.
That is the easiest way to find them.
Their camouflage is excellent.
And what's the biggest you've found here? The biggest one I've ever caught is 14ft! That's a big snake.
Yeah, that's a fairly big snake.
I tell you what, I'll take a look down the other side if you take that side.
So where you coming from, you say? Oh, I'm from Northern Ireland.
We've got no snakes there, Saint Patrick took them all out.
Oh, no snakes? Rather than trek through swamps, I've come downtown to let the snakes come to me.
This unassuming fire station is home to America's leading snakebite response team.
If someone in Miami comes across a nasty-looking snake, these guys are there within minutes.
Come on in.
This is our little corner of the world.
We have our anti-venom bank.
All of this? That's all anti-venom.
95% of what's venomous and can kill you, we have anti-venom for.
Are you finding you're dealing with more constrictors nowadays? More and more constrictors, yeah.
Three years ago we caught 20, two years ago we caught 40, and last year we caught 89.
So it's getting higher and higher now.
If we get one in the Miami area, it'll be here.
This is the place to be.
do we just have to wait around? Grab a chair, we'll just hang out and wait.
The minute I see one, everything just goes - pff - out of my brain and I jump on it.
Joy has come to a Python hot spot in the southern Everglades to search for snakes with seasoned python hunter Joe Wasilewski.
You're going to try and head it off at the pass? Yup.
And bring it out here? I'm going to drag it out here, probably grab it by the tail, if I can.
Once we have it in the open, once we have that thing focused on trying to biteus and not get away You, not me.
No, no, no, no, we're in this together! All right, you have to tell me what I'm supposed to do.
OK.
Cos I'm a afraid that this thing's going to bite.
How dangerous is that? Is this a serious bite? It hurts, trust me.
Depending on how big, they could cause some damage.
But they're not venomous, so they're not going to kill you and that's good news.
Why are you taking me through the water, when we should be looking for them on land? In many cases, they'll take refuge in the water and that actually is one of the times when it gets a bitscary.
All these little dots represent large constrictor reports or recoveries in Miami-Dade County.
All the red dots, those are all Burmese pythons.
The snakes are out here too, but there's nobody there to find them, cos there's no roads, so people don't see 'em.
PHONE RINGS Venom Response.
Lieutenant Wood, may I help you? OK OK.
What colour is he? OK.
And your address is? OK, um, just sit tight and keep an eye on it and we'll get there as soon as we can, OK? All right, thank you, bye-bye.
Have we got one? OK, we got one, it's a snake in a bank.
This should be interesting.
And realistically, if you'd told me even five years ago that I'd be out here looking for pythons, I would have told you you're crazy.
That's how new this Oh, shit! I got him! Here, wait You got it? Yeah, I told you they're fast.
My God, that's huge.
Wait, grab the tail there, let's just Wait, wait, wait, pull it out, keep pulling, let's get the head towards me.
Hold on, wait, don't OK.
Whoa, look at that! Oh, shoot.
Oh, my gosh.
OK No, that's not big, that's a small one.
Actually, feel the power.
I am, I'm making sure it doesn't wrap around me.
Grab it right there, you can feel the two bones right there? Yes, that's the back of the jaw? Yes.
If you keep your hand there, cos they can actually, how can you say, kind of turn their heads.
You got it? Got it.
Got it.
All right.
I'm amazed you saw it.
I just saw it move.
Two more seconds and this thing was in the bush.
We might have found it, but I don't think so.
OK, let's just relax a second here, just take a deep breath.
It seems to be pretty calm now.
OK, so bagging it is another Not problem, because we don't have any problems, but an issue.
OK.
Let's switch again, I got it.
OK.
Take the middle coil, like right there and put it in the bag.
There you go.
He wants a piece of me.
See, if I let him go now, he's going to cut me.
Wait, wait, wait.
Oh, look at him turn.
Whoa.
Yeah.
Right, one, two, three.
Phew! High five? Yes! Where is he? Where is he? Right over here.
We saw him so we wanted to keep him under here.
Oh, good job, excellent.
Oh, he's tiny! Yeah, yeah.
We're slightly disappointed.
No, so was I.
I heard a snake They're looking for big pythons.
No, sorry.
You want to retrieve him? What do I do? How do I get one of these? Just reach under there and get him.
Yeah, but do I have to have some lightning-quick reactions or something? No.
Ah, there you go.
Here, boy.
Yeah, I've got him.
I mean he might bite you, but it's so tiny.
Oh, he's so, so tiny this little fellow.
I can see he's bright orange underneath, is this a defence signal perhaps? Mm-hmm, that's a defence signal.
So he's scared of me, pretty much? Oh, yeah.
This is our first catch of the day.
Next stop, Burmese pythons, with any luck.
By the end of a long and soggy search, I'd failed to see a single snake.
Surely I can bag something bigger than the snake in the bank! 'The fire department took me 'to a snake breeder who lost several pythons in a warehouse fire in 2007.
' Where is it? In the freezer, help yourself.
(LAUGHS) That's enormous.
That's one of my big females, I lost her in the fire.
She's huge.
a use for the dissection, you're more than welcome to it.
Thank you, this is perfect, this is just enormous.
The fun part is getting her out.
Would you mind giving me a hand? Yeah, I think we'll need it.
OK.
OK, I'll take the top half.
Holy cow.
How do you? Whoa.
Now we've got her, there we go.
'Now, surely this has to be the winner.
' Now where? Yes, no? Yes, yes.
OK, good, good.
Wait till you see this baby.
'With our python hunt over, it's time to compare catches 'and select a snake for dissection.
' Yes, no, maybe? Oh, yeah, and it's huge, quite frankly.
Huge? What about you guys, any luck? Me, no, but Joy's got one.
Oh, wow, that is very heavy.
That's really heavy.
Isn't that a beauty? That's a lovely snake.
Let's get her straight, if we can.
OK.
It's quite pretty, huh? Let's just get this one out in comparison.
Oh, my God! Oh, my God, that is massive.
I did tell you.
Whoa, you'd need six people to carry this guy.
That is absolutely huge.
He's enormous, isn't he? Should we just take him the same way, so we've got the head the same end? Stick the heads side by side.
OK, that is a very big snake.
Oh, my God, look how big this is.
That is a huge, huge snake.
Wow.
I didn't realise they got this big.
I thought mine was a big snake when I saw it! Two, three I mean, that's four metres.
Is it really soft and mushy? Is it really soft and mushy? Yeah, very.
Oh, yeah, it's really mushy here.
I haven't felt it since it thawed, actually.
OK, we've got Jeanette from Florida Atlantic University.
She's the reptile anatomist, she's looking after the science of these dissections.
Your first impressions about these two? This is a whopper.
It is a whopper.
This big bodied snake is probably a female.
But it's kind of lumpy-looking and This one died in a fire? A fire and been in a freezer for? For nearly three years.
Oh, wow.
So from an anatomy and a dissection point of view, is this going to be a suitable candidate? It's a great snake in terms of its size, but It's got great size, but boy is it? The viscera are probably pretty, pretty decomposed.
I would say this is going to be not that useful an animal for anatomy.
This one, on the other hand, is really firm still and, you know, when I reach underneath, you know, it keeps its shape.
So, ah, let's work with this one.
I have another one over here that's from the park, so And how big is that one? A little bit bigger than this.
We'll lay them out and make the comparison.
We'll pack these up, take them to where we'll do the dissection and compare the two and crack on.
From the outside, snakes may look like simple animals, but under the skin lies a remarkable story of survival.
Snakes have adapted to thrive in almost every environment on Earth.
Their muscles move their bodies with mesmerising ease.
They've evolved anatomy to sense, squeeze and strike their prey before they swallow it whole.
Their ability to wait months for food makes them master ambush predators.
As scientists, we want to show you the inner workings of the snake and explore how this extraordinary animal evolved.
We're carrying out our dissection in what is a truly amazing location.
It's a swamp-camp right in the middle of the Everglades, where all the action is taking place with the Burmese pythons.
Our team are just doing some basic measuring and weighing.
And for me, the most incredible thing about these giant snakes is not just, for this female, how big it is, but just look at this body.
It is one massive tube with a head at the end.
We are so familiar with our own limbs.
That's how we get around, that's how mammals get around.
And yet this is an animal that is incredibly agile.
It gets all over the place, yet it does is with just a tube.
But these animals are able to use a couple of different ways of getting around.
One of them is, what we would call, "sinusoidal locomotion".
So you'll see this snake putting its body into these S-shaped curves.
It's anchoring in one part and pushing the body forward with another part.
That's the kind of classic snake slithering that everybody, if you asked a child to draw a picture of a snake moving, that's what you'd get.
Exactly.
It's this S-shaped curve that just keeps going by.
And that's actually a bit hard for a real heavy-bodied snake, like this female.
A lot of times you'll see these snakes look like they're just moving forward, in a straight line.
And it's a little bit eerie, but it's remarkable.
When we turn the snake up, you'll see that it's got these scales on the bottom.
And each has a set of muscles attached to ribs.
You're now really starting to whet my appetite.
I want to see under here and see these muscles.
OK, so where should we cut? Let me get it started, here.
So we're seeing these muscles here.
All these white ones running diagonally.
They're going into the skin and they're going to lift the scales forward.
Underneath them is second layer.
It's going in the opposite direction from this layer over here.
But the real power is actually coming from these muscles, which are right on the bottom.
The graceful glide of a large python requires intricate coordination of muscles.
As a section of the belly muscle relaxes, rib muscles pull it forwards.
A contraction then drags the belly along, and a second set of rib muscles keep the top of the snake in synch.
The pattern is repeated along the body to produce a steady, forward motion.
My brief is to get as close as possible to the animals.
And here, in Florida, that's not difficult.
Round here, an encounter with a python is quite common.
Their agile bodies take them almost anywhere.
Pythons like this are so at home in the water.
You can see it glide through, beautifully, using that same S-shaped motion that is uses whenever it's on the land.
It's beautiful to watch.
In their home ranges pythons like this live very close to water.
They're so used to it, they use it for thermo-regulating - controlling their body temperature.
They use it as a way of hunting.
They use it as a way of getting from A to B.
Here in the Everglades, pythons like this have been shown to travel up to 70km during the wet season.
It's astounding! OK.
So we've been working on taking the skin off of this python.
And when we peel it back here, what we see is a very beautiful structure.
If you pull the skin, you can stretch it and recoil it back and forth.
So you see how the scales overlap over each other, almost like a little accordion.
The reason they do that, is there's skin underneath these scales.
So that allows some stretch in here, which is really important because not only does the python have to curve its body, moving through the ground or even swimming, but it also has to be able to stretch its belly when it swallows something big.
Imagine how much can this skin stretch around? Well, it can almost eat me.
Not quite but, you know, maybe if I lost a little weight! A python that was a little bit bigger could probably swallow me because it's really, really stretchy.
Very stretchy skin.
To show us how snakes curve and contort their bodies, Jeanette has prepared the spinal column of another large python.
Wow! That is amazing! Compared to the 33 vertebrae of a human spine, this is truly impressive.
This is hundreds! This snake probably has somewhere around 300 vertebrae.
They just get bigger? From birth.
That's right.
So if we were to go and look at each one of these, what you would find is, when you get that curve, it's really from a whole bunch of vertebrae bending, not so much a sharp bend in any one.
And yet what you're not seeing is any sense of limbs here.
So does this come first and then, in evolutionary terms, and then limbs are somehow kind of attached for a different form of locomotion, or is it the other way around? You've asked a really old question, a really important question.
So one of the things that we can show you is the evidence that these snakes are derived from lizards.
It's easiest to see these things in the male.
And so I'm going to turn this over and you'll see these structures on both sides.
These are called spurs and the males use them in reproduction and courtship.
And what I'm doing here is just simply separating out the muscle from the body wall.
Grab that with the forceps there.
That's muscle, and here we have Oh, look at that.
Look at the bone coming out now.
This is amazing.
Pull this back.
And there we go.
That's the limb.
This is the equivalent of pelvis.
Equivalent of the pelvis.
That's the equivalent of the thigh bone, or femur, and this part on the end is like a fingernail? Probably.
That would be a good description.
So they skip right over the leg.
So it's, so it's like It's like that.
Exactly.
That is amazing.
Evidence.
Evidence of evolution.
That That is incredible.
This vestigial leg, now nothing more than a claw, is evidence that the ancestors of this creature once ran along on legs.
Imagine you had an ancestor a bit like a lizard, with a, sort of, lizard number of vertebrae.
And then in evolution, the vertebrae got duplicated and duplicated and duplicated again.
It's like a goods train and just putting in more and more trucks in the middle.
They're nearly all thoracic vertebrae from the chest.
They lost the front limbs and the hind limbs.
And amazingly, there are vestiges of the hind limbs still there.
It's a very telling example of a vestigial organ.
Something that was once there and was once larger and has now almost completely disappeared, but betrays its history by being still there in a reduced, modified form.
Serpents have been synonymous with evil since the Garden of Eden.
We have long been wary of their forked tongue and slithering movements.
When pythons appeared in the Everglades, there was another reason to demonise them.
Over its lifetime, a python consumes hundreds of prey animals.
Florida's native species were under threat.
'Researcher Clay DeGaynor discovered the first python' A field project, radio-tracking one of the rarest species on Earth - the Key Largo woodrat - came to an unfortunate end.
The rat was found inside an eight-foot-python.
This is what happens when a near-perfect predator is let loose in a fragile ecosystem.
The python's hard wired to hunt.
It has no evil intent.
As for the menacing forked tongue, it is best understood as part of the snake's sophisticated senses.
Snakes, as you might see very quickly, they don't have any eyelids.
Or they appear not to have any eyelids.
In fact, what they have is an eyelid that has fused and covered the eye itself.
And that fused eyelid becomes clear and it's called the spectacle, and the spec But it's actually a scale of the skin.
No, it's actually the eyelid.
It's shed when they shed their skin? It's shed when they shed their skin.
Now, these animals do have a nose, but probably they're not actually smelling with the nose.
They're probably smelling, from what we know about snakes, with the tongue.
By waving their tongue in the air, they're picking up chemicals, just like we pick them up with our nose.
If the tongue were to come out and touch the environment and then go back in, it would be placed back up there, that's called the Jacobson's organ, or the vomeronasal organ.
In essence, that's their chemosensory area.
So let's just cut that off, so we can take a look at the tongue itself.
Thank you.
OK.
If we lay this tongue out, we notice that at the tip of the tongue, it's actually forked, so it has two prongs, a left and a right.
This is going to enable the snake to pick up chemicals on both sides, both the left and the right prongs of that tongue, and compare the left to the right side.
As soon as it knows which side it has a stronger scent on, that's the direction it's going to go.
Another really amazing thing that pythons have, is the ability to see an image with infra-red.
And infra-red is associated with heat.
And so the animals actually have a set of clefts that are their infra-red detectors.
It's almost like having an in-built thermal-imaging camera.
They're going to see the heat.
If they've got a prey animal, say here, they may not be able to visually see it, but they'll be able to sense the temperature of that animal compared to its surroundings, which says this is potential prey.
Python vision is poor and they don't have ears to hear sounds.
But make no mistake, other senses are finely tuned for night-time hunting.
They can feel even the tiniest vibrations in the ground.
Their constantly flicking tongue picks up the chemical scent of prey.
And their infrared sensors lock onto the target.
Even in complete darkness, nocturnal snakes strike with near-perfect accuracy.
These pythons in Australia are able to pluck bats out of the air.
And this mouse may think it's free to forage under the cover of the darkness, but the rattlesnake knows exactly where it is.
The venom kills it in seconds.
Hey, Tom.
Pleased to meet you.
Hi,Tom Crutchfield.
Pleasure to meet you.
Pleased to meet you If you want to know your boas from your anacondas, or your mambas from your vipers, Tom Crutchfield is your man.
We'll go into the Venomous Room first In snake breeding circles, Tom is a giant.
His Florida-based collection of rare and exotic species is world-renowned.
You first.
Just watch your step.
A visit to his Venomous Room is not for the faint-hearted.
Here's an example of the most dangerous North American rattlesnake - the Mojave rattlesnake.
It only takes about 15mg of venom to be lethal for an average 160lb man.
It would take a little more than that for me, weighing a little more than 160lb.
This is a large albino cobra, which is captive raised.
This is from South East Asia.
This particular one is SNAKE HISSES .
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from Thailand.
This snake probably causes more deaths in South East Asia than any other snake.
He's sitting up about a foot or so, and that's about as far as he can strike.
We don't have to run.
You can just tell this thing's angry It's not angry at all? It's not? It's not? It's afraid.
It's afraid? It's afraid.
I mean, what would you do if a giant had you? Now, he's going to turn and he's going to try to bite me.
That was a pretty good attempt.
So, all these snakes kill their prey and would-be attackers using fangs and venom.
But I want to see some snakes with a much more brutal approach.
Some constrictors.
You got any of those? Some constrictors.
You got any of those? We do.
We have constrictors.
OK.
Now, on this one, what you're going to have to do is put your hand down and when you get it, you're going to have to get it behind the neck.
You can't hesitate.
I don't want you to do this sort of thing because he'll see that and he may strike at you.
If he does that, he may bite you.
You have to put your hand down, without hesitation, and grab it behind the neck.
Do you feel ready to do this? Um, yeah.
The worst thing that can happen is you're going to bleed a lot.
I'm not going to let it do much to you.
All right, OK, let's go.
Nervous, but ready.
The head is right here.
Come on this side.
See, it's looking at you.
Don't, don't Go ahead, grab it behind the neck.
Get it out quick.
Now, you can see here Oh, he's already trying to coil me.
He's gone for my arm.
In fact The longer you hold him, the more pressure he'll put.
And he's probably already, he's already cutting the blood completely off, to your hand.
Imagine a much bigger snake wrapped around you.
Every time you exhale, it will squeeze tighter and you can't breathe.
You still, you don't die from lack of oxygen.
What you die of, is your heart stops because that steady, consistent, hard pressure, within less than a minute, your heart stops and you die.
Can you feel the pressure? Look at your hand now, the colour.
This, this snake is piling on the pressure and this is what it does in defence, or in attack.
This is really it's weapon.
And snakes like this have been doing this for a 100 million years.
This is a technique which worked and it's stuck with it.
Look at how his hand looks.
It's literally purple.
It's beginning to hurt now? It's beginning to hurt now? You can feel It's even trying to coil around my back.
I think it wants to finish me off! This thing's going for it now.
Do you mind taking it off? I can take it.
Patty, can you help? She's going to have to unwrap it from the other side.
Hang on.
Turn it loose.
I got it.
Turn loose the head.
Yep.
Oh! Ah.
Ooh! Let's put him back in the box.
It wasn't really trying.
What really is scary to me is, when you look inside this, it kind of reminds me of that movie Alien, you've got another set of mouth inside the mouth.
Look at this, there's a row of teeth here, and then there's also another row inside that, look at this one here.
So there's two rows of teeth.
And they're curving backwards, which is absolutely amazing.
If you actually have an animal that gets bit by one of these teeth, it's instinct's going to be to pull away, but because the teeth are curving inward, that's actually going to drive the tooth further into the animal and really secure and anchor that tooth into it, so it doesn't get away.
What I need to get my head round is how they can actually swallow a prey animal that is many times the size of their own head, because if I jack my mouth open and go, "Ahh", I can get a large burger in there maybe, that's about it.
But nothing bigger than that.
How does it manage to end up with a head that size, being able to take in something that's this kind of size OK, while our head is very fixed, a snake's head is very mobile, in many, many places.
In a human, the lower jaw's just one bone and it just articulates, right with the base of the skull.
But in snakes, they actually have a very complicated lower jaw.
It has another intermediate bone that connects the lower jaw to the skull.
It's called the quadrate bone, you can see it being moved right now, right in here.
The quadrate bone acts as a double hinge, allowing the mouth to open to an astonishing angle.
Unlike in humans, the left and right sides of the jaws are completely separate.
Each is free to move as the mouth splays even wider.
An extra set of upper teeth move back and forth as the snake walks its jaws along its prey.
With the teeth leading the way, the python pulls its body over its meal.
But with a mouth and throat full of fur, how does it breathe? This is the beginning of their breathing passageway.
This is normally going to be locked up into the roof of the mouth like that, to create a passageway from the nose down to the trachea and then to the lungs.
They're normally nose breathers? That's the normal, yeah, that would be the normal at rest position.
But if you've got something big in your mouth, that's going to separate this and block it.
So what these animals would do is actually extend this forward, so If you can grab this If I There you go, you've got that opening there.
It's almost like having a snorkel you can stick out the front of your mouth to breathe.
Not only can they stick this out, but the cartilage gives this windpipe some support, so it's not totally crushed flat, there's still an ability to breathe.
I'm loving this animal.
It's just amazing.
Hey! Yeah, so now he's coiling around it.
He thinks it's a live rat, of course.
He has not been eating for three or four months, so he is really, really hungry.
Given the chance, pythons will consume meals as large as their own body.
But if food is scarce they can last for months on nothing at all.
I've come to a basement lab in Denmark where professor Tobias Wang studies how pythons cope with this diet of extremes.
So you can see the entire snake here.
The rat is lying here, in the stomach now, just a few hours after ingesting.
You can actually see the jaws of the rat, you can see the spine.
Ok, here we have the snake one and a half days after eating the rat.
You can now see that the rat is gradually disappearing.
The head is no longer recognisable, we can't see the forelimbs.
So within the next day or two, this rat will disappear completely The CT scans show how large quantities of stomach acid break down every last bit of the prey.
In order to absorb nutrients from large meals, the intestines undergo a remarkable transformation.
Here we have the snake that is fasting, and here it is 24 hours after eating the rat.
What you can see here is the fasting animal has a very small, small intestine.
But we then look at the animal 24 hours after eating the rat, so the rat is in the stomach, but look at the small intestine, enormous increase.
In the hours before food arrives from the stomach, the python's intestine swells to an incredible size.
But a big intestine takes energy, so between meals it shrinks down and switches off.
So it's perfectly adapted to feasting, and it's perfectly adapted to famine? Exactly.
Gosh, look at the size of this! This is oesophagus, I mean, this is stomach? This is stomach, and look at the size of that intestine.
It doesn't feel like there's anything in there but oh, wait, wait what are these? Is this all fat? We're going to need to open this animal up.
There's a lot of fat and some of this Oh, look what we got here.
Cool! The ovary! Look at that! So this snake was getting ready to breed.
They basically start off with little tiny follicles, oh, man look at the oviduct, wow! Anyway So each one of these is a potential new snake? But it's the very start of it, it's the yolk and the egg inside it that then has to get swallowed by this little tube called the oviduct.
And its like a production line for producing new snakes.
This hole that Joy has her finger into now, is an open-ended tube.
That tube has to swallow each of these one by one and it essentially feeds the tube over the yolk, and it flows then down this tube here.
So, so delicate.
It's then fertilized by the male sperm that's come up the oviduct from reproduction, to produce one of these.
And it's this that then carries on moving down the oviduct and then be laid out through the cloaca.
But there will be a whole chain of these coming.
There's about 20 eggs there, so all those will come down the same production line.
And when they come out, they then all get stuck together and you have a clutch of eggs.
But a clutch of many more than that.
This is just one side.
We can see on the other side If we flip that out the way.
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there's another ovary.
You'll notice that they're staggered, one in front of the other, so this other ovary is all the way up here.
These structures right here look very much like what we would call, corpora albicans, which is the scar from previous matings and previous years.
So if you actually counted up all the scars and these eggs, you've got an indication of the number of offspring this female's produced, which could be a very big number? Yes, it could.
Back in 2006, Everglades biologists found their first python nest.
It confirmed their worst fears.
The pythons were breeding.
In their native habitat python hatchlings are eaten by birds and jackals.
Here in Florida they have few predators.
Alligators will attack them, but they're not part of their natural diet.
Surprisingly, pythons will sometimes eat alligators too .
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although this one proved too much to stomach.
The python's only effective predator is us.
We're going to allow hunters, in hunting season, if they come across a python, they're going to have the legal right to shoot them.
But taking on giant snakes is not a task that should be taken lightly.
What else have we got here then? We do have the longest of all living snakes, and the only snake that occasionally kills and eats people.
And that is the reticulated python of south-east Asia.
OK, help me get it out, guys.
OK, just keep pulling it out.
Oh, he's heavy.
Woah, woah, woah.
You got it? Yeah, yeah, just got a hold of him, just about.
This thing's huge, isn't it? This is only medium sized as well? This is a medium sized.
So they get a lot bigger than this? Yep.
I once sold a snake to a Mr Lou Daddano of Serpent City.
It was a wild caught, about a 23 or 24-foot reticulated python.
He went in the cage with it, with one other helper, and I'd already advised him actually not to do that, at least to have two or three people.
And somehow the snake mistook him for prey, it bit him, constricted him.
His friend began stabbing it with a knife, which didn't work.
His friend then got, er, panicked and ran off.
The snake constricted him and actually killed him, he was clinically dead.
Fire Rescue got there and they used the defibrillators, like they use on human hearts to start them.
They shocked the snake, the snake released Lou and then to start Lou's heart again, because basically he was dead, they used the defibrillators and brought him back to life.
He was on the Oprah Winfrey Show.
Crikey, he got a lucky getaway.
He was an extremely lucky man.
You feel comfortable enough to hold the head? I'd love to give it a shot, if that would be all right.
I want you to put both hands around its neck, tightly, yes.
Tightly.
Yeah, this Now, this really gives you more of an idea, now you're understanding the power of this thing.
This guy's getting a bit fed up of being handled, we should put him back in.
Let's do that.
Let's do this, guys.
I want one of you to undo the front of the cage.
Go do that, Alex, open the front of the cage there.
Whoa, guys, somebody's got to help me here! It is getting seriously hard to handle at this point.
Where are we taking him? Putting him in here.
Into the big cage? OK.
Yeah, now we got to go round and close the back though.
There he is, he's happy.
This is an example of it's more afraid of us than we are of it.
It's just wanting to get away.
Yes, all that was simply to try to protect itself.
A snake like that is not a snake any one person should ever try to handle alone.
The dissection's getting to a fascinating stage now, because the team have taken all the internal organs out.
What you're left with is this fantastic impression of what a snake is.
It's a backbone, with ribs on the sides, and muscles that create this kind of gutter, if you like, that goes all the way down the body, right to the tail.
But laid in the gutter is everything that Joy and the team have laid out on the other side of the table.
And you've got pretty much every part of a snake.
The internal workings of a snake all laid out in a row here.
Jeanette, you've got the heart out? That is absolutely stunning.
And like so much of the snake, it's an elongated structure.
And no diaphragm, so we've got liver right next to lungs and right next to heart.
And here, two kidneys.
And look how it's all squiggled up, very unlike our kidneys that are kind of like a big bean.
And then this massive fat store.
Yeah, this is amazing.
Who would think that in such hot weather a snake would need so much fat? This is fat for energy stores to make this.
'Joy has noticed something strange about the lungs, 'and wants to fill them with water to take a closer look.
' It's going, it's going, can you see it move down there? You got it, there it goes.
There it goes, see that? Look at this.
This one's filled, this is the shorter lung, this is the left lung.
And this is the right lung, going all the way down to here.
I wouldn't have expected this kind of asymmetry, these lungs are two completely different lengths.
For whatever reason, maybe because it enabled them to wrap themselves around bigger prey, snakes became longer and longer and longer.
And, as so often in evolution, that had secondary consequences, that raised new problems.
And in particular, how do you pack all the internal organs into this long, thin tube? In the case of the lungs, snakes did something rather interesting.
The right lung stretches way, way down the body.
But the left lung is tiny, and in some snakes the left lung disappears altogether.
In the case of the kidneys and ovaries it's similar, but in this case the organs are just staggered, one of them is in front of the other.
It's an answer to the problem of how you pack the organs into this very long, very narrow tube.
I've got That's ovary, you don't want that.
GI contents lower 'Our dissection team's final task is perhaps the most important.
'We must search the python's gut to find out 'what species it has been eating.
' Wow, she really hasn't eaten much recently.
But look! There's a tooth.
A little something.
There's a tooth That needs to be in the bag.
They'll want to look at that under a microscope.
Yeah, right.
OK, we're getting some lumpy things here.
What is that? Now should I pour some water on this, or do you want to take it? What is that? What is that? Shall Iclean? Yeah.
Yeah.
Is that a hoof? That's hoof.
Are you sure? Are you sure? That's a hoof.
Are you sure? No, no, no, no, no, no, no.
Hang on.
Oh, no it's not.
It's a No, it's a bird.
That is definitely hoof.
Look.
Look.
This is absolutely amazing because when you clean this off, it is really obvious that this is one hoof from a small ungulate, so that's a, em, a two-clawed animal.
There's hair here as well, isn't there? Yeah.
Look at how long this fur is, too.
So this, this was quite a big animal.
I mean, standing on here like that, This would have been animal, I guess, would have been this kind of size probably, up to its head.
Wow.
We do get, we have feral pigs.
We have small deer, we have feral goats.
That's not pig.
That's definitely either deer or possibly goat.
Probably more likely deer.
Look at that! I've never seen this many sticks in a snake.
Now that must have been in the stomach.
Of the animal it was eating.
Of the animal it was eating.
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of the animal it's eaten.
Surely it wouldn't have? It certainly wouldn't eat it on purpose.
That's amazing! It is astonishing, isn't it? It's the last bit of our dissection.
Finding that hoof is the kind of proof you need.
Here is an animal that is able to take huge prey, many times bigger than the size of its head, swallow it whole and then have such an efficient digestive system, it can digest every part of it apart from a little bit of fur and one toenail.
That is extraordinary.
The toenail belonged to a white-tailed deer, just one of the many animals on the menu as the pythons conquer the Everglades.
It's an odd story that these animals, snakes, with their immense length, their loss of limbs, should be so successful and yet they are.
They're in every continent of the world except Antarctica and perhaps it's a lesson in how successful animals can be if they take what looks like a disadvantage and turn it into an advantage.
There's one final twist to the Everglades story.
(NEWS REPORTER) 'The Sunshine State gets a blast of cold air' January 2010 brought the coldest weather Florida has seen in decades.
No-one knows how many pythons died in the freeze, but biologists fear the worst.
It will take more than a cold snap to halt this remarkable animal's invasion of Florida.
Next week we'll be dissecting a lion and a tiger.
We'll find out if they're the same animal under different skins.
This is a killing machine.
This is the business end.
And solve the mystery of how they roar.
All right.
Here we go.
This has never been done before.
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