Inside Deadly 60 Deadly 60

My name's Steve Backshall...

..and this is my search for the Deadly 60.

Amazing!

That's not just animals that are deadly to me...

but that are deadly in their own world.

My crew and I are travelling the planet.

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

Agh!

For me, Deadly 60 is all about finding out

what's unique and unusual about deadly animals,

but we can only go so far. Until now.

Today, we're going to find out what makes deadly animals tick.

We're getting inside their heads, inside their skulls.

We're going Inside Deadly 60.

This is the Oxford Museum of Natural History,

and it is my favourite building in the world.

In this great hall, and endless dusty rooms beyond,

there's fur and feathers,

skulls and skeletons, from almost every animal on the planet.

And to me, these are so much more than just dead animals.

You can learn so much about creatures

from their skulls, their skeletons, their teeth -

how they live, what they feed on, and how they hunt.

In this special, we're going to have a look inside

some of the top predators we've encountered on Deadly 60.

We're going to look under the skin, ruffle some feathers,

stick our heads in the mouths of these lethal predators,

and uncover what makes them such successful hunters.

We couldn't come to a natural history museum

without at least mentioning the mightiest predators

that ever roamed the planet - the dinosaurs.

This is a T-rex, and if he was alive today,

he would certainly make it onto the Deadly 60.

In fact, he'd probably eat all the other animals.

But believe it or not, we already have on our list

plenty of creatures that are descended from the dinosaurs.

The animals I'm talking about are all around us.

They are...the birds.

Scientists have found many similarities between birds

and dinosaur skeletons.

Fossils have shown that dinosaur scales

may have evolved into feathers.

If it seems far-fetched that today's birds are descended from dinosaurs,

have a look at this.

This is the skeleton of a moa - a giant, flightless bird

which only went extinct about 400 years ago in New Zealand.

Have a look at those legs and feet. They look just like a dinosaur.

Absolutely exactly the same.

And, looking at that, it's not that much different from...this.

This is an ostrich, and this is a completely modern bird.

These are around us now and look at those -

those could easily be the legs and feet of a dinosaur.

Ostrich haven't made it onto the Deadly 60.

But birds that have are the birds of prey.

And this is a skeleton from a white-tailed eagle.

There's a lot of things about this that are very special.

The skull has a fiercely sharp, hooked beak.

Very, very light, because there's no teeth inside.

Here, I'm going very carefully because this is ever so fragile...

Look at this breast bone - it's absolutely massive.

And that's for attaching the flight muscles -

those incredibly huge pectoral muscles that drive the wings

and allow it to fly, like this.

We're big fans of the birds of prey here on Deadly 60,

and quite a few have earned a place on my list.

We've raced a peregrine falcon...

..been hunted by a goshawk...

..seen the teamwork of vultures...

experienced the sheer size and majesty of the harpy eagle,

and in South Africa, had the honour of flying with a black eagle,

to see how effortlessly they soar the skies in search of their prey.

Run, run, run!

And there he is, look!

We're sharing the air with a black eagle! How good is that?

I'm having to use a paraglider -

and the skills of its very experienced pilot -

just to stay airborne.

But with a twitch of its tail, and a slight adjustment of its wings,

this beautiful bird can turn, soar and dive at incredible speeds

towards its supper.

The birds of prey are truly masters of the air.

To help them achieve this,

they all have a secret hidden under their feathers.

And to find out what it is, we have to look closely at their bones.

The thing that keeps birds airborne is lift,

and the biggest enemy of lift is weight.

So, everything about the bones of birds of prey

is all about keeping them as light as possible.

And to give you a demonstration of quite how light they are,

these are all of the bones from one white-tailed sea-eagle.

I know it's a little bit grim having them in a pan like this,

but...if I put those on one scale there,

I have here a bag of sugar.

Let's have a go and see how they balance.

A full bag of sugar weighs about a kilogram.

Whoa! Almost there.

OK, so it's just about balancing now.

That is utterly remarkable.

So just how can an eagle this size weigh so little?

Well, the answer lies in its skeleton.

The bones of birds aren't solid,

but are made up of a honeycomb-like structure.

This makes them strong, yet much lighter.

They also minimise their weight by having no large jaw bone,

no teeth, small skulls and small tail bones.

We're talking about a bird of prey

that can take things as large as a fox or a sheep,

and its bones weigh about the same as half a bag of sugar.

That is totally remarkable.

All birds of prey have this ultra-lightweight skeleton.

Combine this with razor-sharp claws and beak,

and they're pound-for-pound

some of the deadliest predators on the planet.

For me, the most beautiful skeletons of any animals

are those that belong to the snakes,

and I think they really tell a very strong story as well.

This here is the skeleton of a very large-bodied heavy snake.

It's a python of some kind.

Now, I can't touch this one because it's quite an old skeleton,

and it might fall apart.

But what I can do is show you up close - using this little camera -

what it feels like to fly alongside

the skeleton of a truly giant snake.

OK, here at the top, that's the backbone - the vertebrae.

You can see they're all tightly linked together.

This interlocking spine

gives the snake's backbone rigidity and strength.

And running down here...

these are its ribs.

It's obviously got rather more than we have, and the reason

that that is so important is that muscles attach to bones,

and where they do attach to bones is where they're at their strongest.

So, we've got hundreds of ribs alongside each other,

forming a cage like this.

The muscles that attach to them can be really, really strong.

And that relates to how this particular animal hunts.

It uses those powerful muscles to constrict -

that is, to squeeze the life out of - its prey.

I had first-hand experience of a constrictor's power

when I got into a rather tight squeeze

with a boa constrictor in Costa Rica.

This is what constricting means.

If you see me starting to go blue or purple in the face,

then I might need a little bit of help!

Constricting basically means to strangle -

to suffocate the life out of prey.

And that's how this magnificent animal...

SNAKE HISSES ANGRILY

..manages to kill the mammals it's feeding on.

Ooh! Its tail's going round the back of my neck now.

It's just finding places and ways of getting purchase

to use its really strong muscles in choking me.

But the snake wouldn't have anywhere near the same strength

if it didn't have all those ribs to attach its muscles to.

Actually...yeah...it's amazing how strong it is!

I mean, this snake is only actually feeding on mammals

about that sort of size, maximum.

And it has the strength to choke the life out of me.

I mean, I must be ten times, twenty times the size of its normal prey,

and he easily has enough strength to choke me!

Constrictors will occasionally take on

much larger animals than themselves.

So what happens when the meal you're trying to eat

is four times as wide as your mouth?

Well, the way they deal with this mouth-splitting meal...

is pretty horrendous.

So far, so frightening, but it gets even better

when you get a look inside one of those big snake's mouths.

Right... this utterly horrifying skull

belongs to an African rock python.

I've got to be very careful how I handle it.

But this really shows you why it is such a ferocious predator.

You can see the teeth are so sharp,

they're actually getting stuck on my rubber gloves.

They point backwards so that once it's got a hold of its prey,

it doesn't let go,

and then...

along the top jaw is an extra two rows of teeth.

That is a really scary mouth.

But that is not what is most remarkable about this skull.

The incredible thing is that a snake that big

can swallow things that are bigger than its own head.

The way it does that is that back here,

it has particularly stretchy ligaments

to allow this jaw and the upper jaw to really stretch apart

and be absolutely massive.

And then here, on the lower jaw, it's not joined at all.

That allows these two independent sections of the lower jaw

to walk their way down prey, swallowing it whole.

But it doesn't stop there.

This snake can divide not just its lower jaw in two,

but can also divide its upper jaw,

so that its head is in four main sections.

Two halves of the lower jaw and two halves of the upper jaw.

Elastic ligaments connect the four sections,

allowing them to move independently.

The snake's jaws walk over the prey,

guiding its victim down into its stomach...

where acids will break down the bones, hooves and horns

into liquid nourishment.

And whereas our ribs join at our chest,

the python's aren't connected...

..and can expand to enable it

to consume an animal three times as wide as its own head.

This snake might not eat again for a whole year.

Some of the most exciting encounters we've had on Deadly 60,

and sometimes the most frightening, have been with fish,

but very big fish, with very big teeth.

I'm talking about the sharks.

On the Deadly 60, we've met loads of sharks. From the whale shark -

the biggest fish in the sea...

What a wonderful, beautiful giant!

..to sleeker, more nimble blacktip sharks.

Wow!

In the Philippines, we met the mysterious thresher shark.

And in South Africa, the ragged tooth shark.

Now, I am a total shark freak,

and I reckon there's few more impressive things in the world

than looking inside the mouth of a shark.

This here is from a shortfin mako shark.

It's one of the fastest sharks in the sea.

The jaw itself is not actually made of bone.

It's made of a softer substance called cartilage.

But there's nothing soft about these teeth.

Because the mako shark feeds on fish,

which are slimy and slippery and quick,

the teeth themselves are quite thin, point backwards,

and they're impossibly sharp.

If I was to actually rub my finger down that edge there,

I'd probably get cut.

It's mightily impressive. And look at the way here,

the teeth almost seem to spill right out of the mouth,

forming a working fish trap.

This, however, is very, very different.

And that's because this is a tiger shark,

and it feeds on completely different things.

Tiger sharks are swimming dustbins, and will eat just about anything.

They do eat fish, but they'll happily also eat sea birds...

..other sharks...

and even sea turtles.

But how do they get through the turtle's protective shell?

If I open this up, wow!

Right, you can instantly see

how different those teeth are.

In close-up, they have a serrated edge, just like a kitchen knife,

and work almost like a can opener.

The tiger shark can actually bite

clean through the shells of sea turtles,

which is one of its favourite foods.

But it gets even cooler.

If I turn this around slightly,

and you look at the inside of the jaw...

..lined up there are one, two, three, four, five rows of teeth,

all waiting to spring into position when the front one breaks.

It's like a conveyor belt of teeth

that keeps on going through the shark's life,

so it doesn't matter if it loses a tooth -

another one will just roll into its place.

This would have to be the most formidable predator in the sea.

I was lucky enough to swim with these magnificent predators

when the crew and I travelled to the Bahamas.

Look! That's a seriously big tiger coming in!

A big female!

Not only do tiger sharks have serrated teeth,

but they can get to be huge.

This female tiger shark

looks to be twice the size of our cameraman, Simon.

All my years diving with sharks,

and they still have the power to surprise me.

Even that huge bulldog of a female tiger

was just nosing cautiously between Simon the cameraman and I.

It was almost like she was being polite,

she didn't want to jump the queue!

For all that, though, the tiger shark has to be on the Deadly 60.

They're big, they're powerful, they have enormous can opener teeth,

and they're one of the wonders of the ocean.

That was incredible.

Over the course of Deadly 60,

there's one group of animals I keep coming back to,

because nobody is ever going to doubt that they're deadly.

And I'm talking about the crocodilians.

Gharials,

caiman,

and the crocodiles.

This here is the skeleton of a Nile crocodile.

It's one of the largest reptiles in the world,

and one of the fiercest crocodiles.

This one is about 2.5 metres long. They get to be about six.

Yep, you heard right - six metres! That's as long as a minibus.

OK, let's get down to specifics. This is the neck, here.

And you can see that the vertebrae are tightly packed,

which gives it a rigid, strong structure.

Just like in constricting snakes,

this gives the backbone added strength...

..and allows the crocodile to rip its head from side to side

and take down enormous prey - things as big as buffalo.

But how do such enormous predators track down their prey?

Well, they use the first of many lethal attributes.

Living in water, crocs need to be able to open their mouths

without the risk of drowning.

When the head's submerged,

a valve at the back of the tongue seals the throat

and completely stops water pouring down into the lungs.

Air tubes open behind this valve and run to the nostrils

enabling the crocs to breathe

as they lie concealed beneath the water's surface.

They can lie underwater not breathing

for as long as three hours.

And in order to conserve oxygen and energy,

they can slow their heart rate from 40 to three beats per minute.

So that's all pretty impressive,

but let's come to the business end of the beast.

This is the skull. This is from quite a decent sized Nile croc.

And the most noticeable thing is just the incredible weight of it.

I mean, it's probably about the weight of a sack of potatoes.

I couldn't hold it like this for much longer,

so I'm going to put it down.

That huge head houses

some of the strongest jaws in the animal kingdom.

And also some of the most brutal teeth.

OK, let's get a look at these fantastic teeth.

That one there is probably the most impressive.

It's about the size of my thumb.

These teeth interlock and spill out of the jaw.

They keep on growing and they get replaced if they get broken.

Now that is a serious set of gnashers.

With their formidable deadly attributes - powerful jaws,

pointed teeth and stealth skills - crocodiles are the perfect predator.

It's easy to see crocs as prehistoric dinosaurs,

but they actually highly sophisticated creatures.

Not only that, but at feeding time,

they often reveal an unexpectedly social side.

After a croc makes a kill, others come and join the feast.

While some crocs will anchor the prey down using their huge jaws,

another takes a bite, locks its neck and back muscles,

and begins to spin.

This is known as the death roll, and something has to give.

The croc tears off a chunk of meat, which can be quite a mouthful.

A large crocodile's bite is five times more powerful than a lion's.

Working together, every last bit is eaten.

Bones, horns, hooves. Nothing is left to waste.

Crocodiles often lose teeth doing this,

but for them, it's no big deal.

Over their lifetime, they can grow up to 3,000 new ones.

But not all reptiles use force - brute force and strength -

to hunt down their prey.

In this box, I've got a very different kind of skull.

This belongs to a monitor lizard.

It's also a reptile, but it couldn't be more different.

While the crocodile's skull is incredibly bony and heavy -

all of the gaps are filled in with thick bone -

this monitor lizard's skull is incredibly light.

You can see that instead of thick bone,

it has tiny little struts to hold the skull together.

That means it's much lighter,

and the animal itself can be much faster over longer distances

and longer periods of time.

It's that lightweight skeleton that makes monitor lizards

one of the most versatile hunters of the reptile world.

They're nimble climbers,

even expert divers.

Whatever it takes to get a meal.

And as well as killer claws,

they carry a face full of ferocious teeth.

Get a load of those teeth.

Very, very different to the crocodile teeth.

They're curved backwards, so that once this gets a bite on something,

it's certainly not letting go.

And these are the lower jaws.

If you see that together,

you can also see that the bottom jaw has enough movement

to allow the monitor lizard

to take bites out of the things that it's feeding on.

So, we've seen how its lightweight skeleton and gripping claws

make it ultra-rapid when chasing down prey.

Add to that its fiercely sharp teeth,

and jaws that allow the monitor lizard

to crush the skull of its prey in one bite,

and you can see why they had to be on the Deadly 60.

I've seen these animals in the wild, and believe me,

they are absolutely fearsome.

Everyone keep your eyes peeled and give me a shout if you see anything.

In the Philippines, we heard that monitor lizards

were sniffing around the garbage heaps of a local village.

And it wasn't long before we came face to face with one.

(He's there!)

This is a bit closer than I would really be comfortable with.

Inside that mouth is one long line of teeth

that are honestly razor-sharp,

backwards curving, and covered with...

He's tasting my face!

He just stuck his tongue in my eye!

OK, this is where I start to get a little bit nervous.

He can move very, very fast.

From there, he can have his arm in his mouth in a second.

Look at him tasting my hand!

As I was saying, the mouth has razor-sharp teeth

which are covered in bacteria.

And those bacteria, once they get into a wound, once he cuts you open,

will almost instantly start to become infected.

Any bite from a monitor lizard is very, very serious indeed.

Luckily, this guy can see that I'm not food.

So, our Deadly 60 superheroes -

from birds of prey to sharks to crocodiles -

are phenomenally complex machines.

And these skeletons are the structures which drive them.

They're incredibly different, but they have a lot in common, too.

There's so much more than meets the eye to animals, so much to learn.

All you have to do is get really under their skin!

Ow!

Ooh! Just stung right into the end of the tongs.

Join me next time for more animal encounters on Deadly 60.

Ooh! He actually flicked venom straight at me.

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