Cold-Blooded Killers Deadly Pole to Pole

My name's Steve Backshall.

And this is Deadly Pole To Pole.

Ohhh!

From the top of the world to the bottom...

Whoa!

..deadly places...

..deadly adventures...

..and deadly animals.

And you're coming with me, every step of the way!

Arghhhh!

Deadly.

In this special edition of Deadly we're dealing with

a group of animals that have dominated our planet

for several hundred million years.

Oceans.

Mountains.

Deserts.

Even skies.

These are the cold blooded killers.

In particular I'm talking about reptiles -

crocodiles, turtles, snakes and lizards.

They are amongst the most successful predators on Earth.

Some roamed the planet before the dinosaurs.

And that's down to their skills.

Bites,

speed,

supersenses

and venom.

But first - what does it mean to be cold blooded?

This doesn't mean they always have cold blood.

It just means that their blood can fluctuate between warm and

cold depending on the outside temperature.

I'm in Florida to show you what I mean.

So, we have one rattlesnake, rattling.

Now, these animals perceive the world in a whole different way to us

human beings.

It's very, very difficult to appreciate that with our own senses,

but we do have a bit of technology to help us out.

This is a thermal imaging camera

and it sees the world in a whole different way to us.

It sees heat.

So as I'm standing here as a warm blooded mammal

hopefully what Lizzie's seeing is my body,

fairly orange, showing that it's hot,

my eye sockets - which will probably be the hottest thing -

will be almost white

and us as mammals need to

maintain that constant body temperature by eating food.

'In fact as much as 75% of what we eat is used to

'power our internal heating systems.

'For cold-blooded reptiles though it's a very different story.

'They don't generate their own heat,

'instead they get it from their surroundings.'

Now, it's been a cool night and

the snake's body temperature will have dropped right down,

so now hopefully you should be seeing a snake whose body

appears to be blue or even black

because its blood genuinely is cold right now.

Can you see that, yeah?

Right now this snake might be pretty chilly,

but that certainly isn't the whole story.

What it's going to do, this time of day is

try and find a nice warm place where it can lie out in the sun and bask

and that will bring its blood temperature right up.

And if I place our rattlesnake down here,

onto the warm surface,

hopefully it'll start to absorb some of that warmth.

'This process takes about half an hour

'so I'm going to speed it up so you can see what's happening.

'You can see from the snake's change in colour that it's absorbing

'the sun's heat and warming up.

'The snake has gone from cold blooded to warm blooded.'

That's cracking.

It's such a contrast from where it was before

and what's really interesting as well is that it's uniform,

that change in temperature has happened throughout the whole snake.

Reptiles still need to be warm to be active.

So this ability to absorb heat is vital

to them once it's time to find food.

Taking on their heat from their environment

means they can be incredibly energy efficient.

It means that in lean times when prey is scarce

they can go without eating for very long periods of time.

Days, weeks, months, even years.

The record amount of time that a snake has gone without eating,

believe it or not, is over three years and at the end of that

the snake was still in perfect

condition and could carry on hunting.

It means that these animals are unbelievably

energy efficient and that, for a hunter,

is one of the finest tools you could ever hope to have.

When they're warm they can be seriously speedy.

'From the lightning strikes of the world's snakes...

'..to the snappy reactions of the caiman that bit me in Argentina.'

Aaargh!

Are you all right?

'They can move at surprising speeds.

'Once warmed up, cold blooded reptiles can even chase down

'the permanently powered up mammals.

'Meet the perentie from the Australian outback.'

And its prey of choice,

the rabbit.

Now most people would have trouble

keeping up with the bounding bunny but not the two-metre long

sprint champion perentie.

Once they've locked in, the chase is on.

Speeding at over 20mph, the cold blooded perentie can

outrun their warm-blooded prey.

It's unusual, but they can sustain these chases

for several hundred metres.

And reptiles aren't just fast on their feet.

This is the fastest tongue in the west.

Well, not the west,

but Madagascar.

For a reptile lover, Madagascar is absolute paradise

and for one lizard in particular -

the chameleons.

This is a male Parson's chameleon

and it's pretty much as big as chameleons get.

And this is a dwarf chameleon.

It's the smallest chameleon on the planet,

one of the smallest reptiles and

way smaller than the insects that this bad boy would eat.

Many chameleons hunt in the tree tops.

Their eyes swivel in all directions, looking for a juicy insect meal.

They can see nearly 360 degrees,

scanning for their prey whilst standing perfectly still.

This incredible eyesight gives them a huge advantage.

But the chameleon's most deadly skill

is all down to how it catches its insect prey

and one of the fastest tongues in the whole animal kingdom.

This tongue is spring-loaded.

Sometimes longer than the chameleon's body,

and with a sticky tip that can envelop an insect.

The speedy tongue accelerates even faster

than a jet engine.

Blink and you'll miss it.

It's the turbo tongue of the cold blooded world.

Aaargh.

Ohhhh!

Messy eaters, aren't they?

With the fastest tongue in the animal kingdom,

accelerating faster than a jet engine,

the chameleon.

Deadly...

From the speed of the perentie to

the lightning fast tongue of the chameleon,

reptiles are full of surprises.

Surprise itself can be a weapon -

ambush - allowing them to unleash killer bites.

Our next cold-blooded killer uses a lazy lure to attract prey

to come to it, before unleashing a snap-attack.

We've come to an ecology centre where

they educate people about the local environment and local wildlife

and they've got one resident here who is a genuine superstar.

In this pond is a really big alligator snapping turtle.

And he's called Big Al for a reason. He's massive.

So I'm going to take this quite easily.

There he is.

Now, the alligator snapping turtle is the largest

species of freshwater turtle found on earth and this is a true monster.

These animals are notorious for having an extraordinary bite.

The mouth has no teeth,

but it does have an edge to the jaw that is truly scalpel sharp.

And it's not just their bite that makes them cold blooded killers.

They have an enticing lure which is a triumph of evolution.

The way they entice them is with a remarkable little structure.

And it's just like a little wriggling worm or a maggot.

An enticing little morsel for any fish, frog or bird.

It'll go right into the mouth of the alligator snapping turtle,

and when they do, this is what happens.

Ha! OK. Well, that was pretty quick,

and obviously you would not want that to be your fingers.

Using a slow motion camera you can see

that sharp beak slicing through the carrot like a Samurai sword.

Hah. What a sound!

The alligator snapping turtle, a true legend of Deadly,

and the mightiest snap in the swamp.

All pretty impressive, but when it comes to sheer force

there's one group of reptiles that's head and scales above the rest.

With the strongest bite we've ever recorded...

the crocodiles.

Crocodiles are among the most ancient of reptiles.

They live in rivers, lakes and even the sea.

Muscles at the base of the tail give the crocodile propulsion

to launch itself out of the water...

..and grab its prey with slam shut jaws.

In fact, they have the strongest recorded bite

of any animal on the planet.

I've had some pretty snappy encounters in the past.

With Orinoco crocs in Venezuela...

..and the heavyweights in the crocodile world,

the Australian salty.

But undeterred, I ventured to get even closer and test

this mighty bite for myself.

This looks like it.

In Cuba, we got a call that an American crocodile was hanging

out near this boat.

Right, let's go see what we've got.

Hola.

-Como esta?

-Hi.

Right. Yes.

That is a proper American crocodile.

And I'm guessing that he's got a pretty potent bite force.

'To test it out we brought the Deadly bite test gauge.

'And to tempt him to chomp on it we're strapping on some

'chunks of chicken.'

OK. Crocodiles have completely

individual personalities, so I really can't

predict how this animal's going to react.

And this one looks like he's paying us some interest.

Might just get my feet out the way.

Right. Here he comes.

OK, that's just a little nibble with the front part of the jaw.

It's now going to use the whole body to try and wrench that.

Oh, wow!

Just the slightest squeeze of the jaws and the gauge goes zipping up.

Yes!

That's a big croc.

He's gone over 1,000 pounds per square inch.

'I'm very glad I got my toes out of the way,

'that force is like the weight of a small motorbike landing on you.

'But believe it or not, there's a species of crocodile

'that can more than triple this croc bite.

'The saltwater croc.'

This champion chomper hasn't just got the strongest

recorded bite of all the crocs, but the strongest on the planet.

At over 3,700 pounds per square inch,

the force of this bite would be like the weight of a car landing on you.

The crew and I travelled to Australia

to a crocodile research centre to put it to the test.

But things didn't go quite to plan.

Having to put this gauge into some of the biggest jaws

on the planet is not for the faint-hearted.

-Whoa!

-You OK?

I just got absolutely smashed.

Whoa! Good lord, the power of the animal is phenomenal!

That is something else.

Unfortunately now, we've lost the bite gauge, the camera

and the stick.

Holy moly. Ha, ha!

Our bite gauge got completely destroyed so

we didn't get our reading, but I think it's safe to say

the saltwater crocodile has bite.

Killing with phenomenal force,

and the strongest recorded bite on the planet,

the saltwater crocodile.

Deadly.

We've seen that reptiles can be seriously strong and

use speed and strategy to deadly effect.

But some have something even more extraordinary -

supersenses.

Snakes are superb predators,

perfectly adapted to hunting their prey using evolved supersenses

far beyond our own.

The first of these is a tongue for tracking prey.

And to show this in full effect, the tree-dwelling boomslang.

We've got a slow motion camera to see

if we can catch a glimpse of that tongue in action.

There it goes. There it goes.

Right, I'm really hoping Johnny managed to get that

because when you see it slowed down,

actually it is extraordinary what that tongue is really doing.

So, the tongue comes out, it waves up and down,

you can see both sides of that forked tongue

actually trailing into the air

and then dropping down onto the branch itself.

What this snake's doing is tasting its world.

Now if any lizard, a chameleon perhaps,

has been wandering along this log,

it will have left an invisible trail behind it.

And snakes can use this to track them down.

But some snakes have a sixth sense.

Which gives them the ability to hunt in complete darkness

by seeing heat.

We're in a cave in Cuba

in search of a snake that's mastered this supersense, the Cuban boa.

But for us to film it we have to switch to infrared.

Walking through the cave, the crew and I can't see a thing,

but we can feel all kinds of creepy crawlies

scuttling about our feet.

And it's not long before we find what we're looking for.

No way! There's loads of them.

So, this is why we've come to this cave. Cuban boas.

And they are pretty much everywhere.

There's one reason why this snake is here and one reason alone,

and that's to feast on bats.

I'm just trying to keep my eyes on this snake,

because I can't really see it.

'These snakes hunt in complete darkness and like us

'they can't rely on their eyes.'

But, they do have several senses that enable them to find their prey.

The first of those, as with all snakes, is their tongue.

That'll help it to zone in on bats that are roosting in the walls

and in the ceiling,

but also it has special scales on the lip which can see heat.

Cave boas probably see the world

as if through the lens of our thermal imaging camera.

Their warm bat prey stands out against the cooler background,

so the boa can spot them and strike with pinpoint accuracy,

even in the pitch black.

The Cuban boa.

It may make its home in a nightmare of a place,

but for me this is a dream of a snake and, undoubtedly, Deadly.

With a heat-detecting supersense for hunting bats in complete darkness,

the cave boa is definitely...

Deadly!

When it comes to being a cold blooded killer one of the best

ways to take down prey is...

..venom.

Venom is a toxic fluid used to paralyse, disarm and digest victims.

And reptiles have some of the most deadly on the planet.

I'm in Australia to meet the most venomous reptile there is.

It's the inland taipan.

'They live in the Australian outback and are seriously difficult to find.

'But luck was on our side.'

Stop, stop. Steve, there, there!

Well, I don't actually believe what I'm seeing.

We have, at the side of the road,

the most venomous snake on Earth.

This is a fierce snake

sometimes known as an inland taipan.

Head drawn back into an S shape.

Just making out like it's ready to strike,

you can come a bit closer, Graham.

It's OK, it's fixed on me at the moment, not on you.

This has the most toxic venom of any snake on Earth.

'But that venom isn't meant for humans. It's for their rodent prey.'

So around here there are loads of burrows of rats

and those animals can be very, very fast,

so what the fierce snake needs to do is to bite them,

inject enormous amounts of very, very toxic venom

and stop them moving very quickly.

The venom is very complex,

but the main constituent part is what's called a neurotoxin.

That is a toxin that affects the nervous system.

It's very, very fast acting

and one snake is said to have enough venom to kill 100 people.

It's an absolutely phenomenal hunter, very rare,

very difficult to find and the most venomous snake on earth.

You were very lucky, man.

Very lucky, man.

That's one of the best looking fierce snakes,

wild fierce snakes, I've ever seen. You know, far out.

Though venom use in production is quite common in snakes,

it's much less common in the lizards.

This is one of the exception.

It's a Mexican beaded lizard.

Unlike snakes that have venom glands in their upper jaws

and inject their venom,

these creatures have venom glands at the back of the lower jaw.

And they don't have the ability to inject it,

instead they have to chew it into their prey.

This one here wouldn't have enough venom and it isn't strong enough

to kill a human being, although it would certainly hurt.

However, there is one lizard that definitely does,

and it's the largest on the planet.

In Indonesia is an island ruled by a truly prehistoric predator...

..the Komodo dragon.

Dragons aren't just a thing of myths and legends.

They're loaded with everything that makes a

cold blooded killer deadly -

strength,

speed,

a supersensing tongue,

and toxic venomous bite.

In fact, they're the biggest venomous animal on land.

My crew and I are journeying to this island to

see if we can come face to face with these mighty reptiles.

As soon as I arrive,

I'm issued with a state of the art dragon defence device.

Right. OK.

So being as this is a national park,

no-one's obviously allowed to carry any guns

or anything that could harm the dragons,

but you do need a little protection, so I've got a stick!

What use that's going to be against a three-metre monster

I have no idea, but it's better than nothing.

With no roads on the island we continue on foot.

First we headed to the rangers huts, which are a regular dragons' den,

and it wasn't long before we saw one.

Oh, my goodness, right there look.

Yeah. Our first dragon is right in front of us.

'And it wasn't alone.'

Over there, look.

Such an awe-inspiring animal.

'Suddenly there were dragons everywhere.'

Just surrounded by dinosaurs. Oooh, yeah.

They can really motor when they need to.

'We hadn't expected to see quite so many.'

So these are Komodo dragons, the largest lizards on earth.

OK, big fella, it's all right.

It's OK.

Don't want to move quickly

because that could trigger a predatory response.

Much safer just staying calm and still.

And also a good distance from that venomous mouth.

Komodo dragons use their serrated teeth

to rip into their victims' flesh

before seeping toxic venom into the wound.

The venom is slow-acting,

so the dragon has to sit back and wait.

Venom not only guarantees the Komodo a meal,

it also means they can take down prey many times their own size.

And once they do, it's a communal feast.

The dragon's killing technique takes days,

so to see the dragons at their deadly best,

I rigged up a chunk of meat to try and draw them in.

But then something happened that took us by surprise.

OK, we've already got interest guys so, um...

Yeah. Right. OK, let's move, guys, let's get going.

'They locked on to me and the crew.'

OK, guys, go, go, go, go. OK.

-You OK?

-Yeah, yeah.

OK, here they come.

Gray, Gray, Gray!

'It was an unexpected turn of speed and aggression.'

Look at that, that's a completely different animal.

Back up, Graham, back up.

I cannot believe the total change in attitude of this animal.

No, no, no, no, no, no.

As soon as they got food on the brain

they changed from a slumbering, slow-moving creature,

into a predatory dinosaur

and all of a sudden they're not just hunting the meat,

they're hunting us.

Whooah! Whoa, whoa, whoa!

OK, one of the dragons has the meat.

Over there, look, it's tearing into it.

Wow!

I can see into its mouth - the curved, backward-facing teeth

and look at the tail thrashing around.

Now, Komodo dragons have very, very

occasionally attacked and even killed human beings.

But you can see that once an easy source of food is available

they're not focusing on us any more, they're just scented on the meat.

In all my years of wildlife watching this is one of the only times

I've felt like an animal would attack me if it got the chance.

They are one of the world's most formidable predators.

With speed, strength, super sensing tongue and venomous bite,

the Komodo dragon has to be the ultimate cold blooded killer.

Deadly.

Waaah!

'Join me next time for more Deadly Pole To Pole.'

This is a true monster.

Whoa.