Original subtitles

Narrator: Ever wondered why a spider might sparkle?

Could this be some kind of courtship ritual?

Narrator: Or why an animal would play a prank?

[ barking ]

Without the pictures, no one would believe it.

Narrator: And could anything take on the great white shark?

The kind of teeth marks we see

Are almost something mammal-like.

Narrator: Nature is awe-inspiring,

But sometimes it just doesn't make sense.

Man: I have never, ever seen anything like this.

Strange animal behavior,

Unexpected events captured on camera.

[ animals screeching ]

The truth behind them is astonishing.

Woman: My god!

Nature's greatest mysteries solved.

-- Captions by vitac -- www.Vitac.Com

Captions paid for by discovery communications

June 2017, williamsburg, virginia.

A mysterious sequined spider lights up the night

Like a disco ball.

Schreiber: So a woman sees a spider on the floor.

She decides to flash her torch onto it just to see it better.

When she does, she gets an amazing sight.

Suddenly, it was just lit up with colors,

All these different colors.

I'm a real fan of spiders, and I always love it

When I see something that I've not seen before,

And I think it's absolutely beautiful.

That's great. I like spiders in any context,

But a sparkly spider, that's perfect.

Narrator: So what is making this spider sparkle?

Riskin: The first thing that comes to my mind

Is bioluminescence, right?

Bioluminescence is just light

Coming from something biological,

And there are all kinds of different creatures

That can make light with their bodies, so the question is,

"is that what's happening with this spider?"

It might be doing it for certain reasons

Like trying to attract a mate, to make a sort of call sign.

Narrator: There's one insect that's famous

For lighting up for the ladies.

Now, when fireflies bioluminesce,

They're in total control of it.

They turn it on.

They turn it off, and they flash their bioluminescence

In a very specific way because that is sexy to females.

So one suggestion is,

Could this be some kind of courtship display,

A way of the spider attracting a mate?

Peacock spiders do these incredibly elaborate displays.

These are males doing their very best to impress the females.

Narrator: But could spiders

Really make themselves glitter in the gloom?

Perhaps not.

Burke: As yet, there is simply not one documented example

Of a spider that produces bioluminescence,

So at the moment, that's a really unlikely explanation

For what's going on here.

Narrator: But there could be another way

Of getting to the essence of the story.

Could it be iridescent?

That's an interesting theory.

Iridescence is when, like, looking at a soap bubble

Or looking at certain beetles, the light is broken down

Into its various different components,

And so it looks amazing.

Narrator: In case you missed that,

Iridescence occurs when light bounces off a surface

And is scattered into different colors

Like the feathers on this hummingbird,

Which appear to change from green to red and blue

As it dips its head.

Depending on the angle we're seeing it from,

The surface seems to change color.

Burke: It's basically where animals

Are able to produce color without a pigment.

The morpho butterfly -- which is a butterfly

That's found in the amazon rainforest --

It's an amazing example of iridescence.

It has these beautiful, shiny, blue wings.

Narrator: Like the hummingbird,

This butterfly is actually brown.

It's the iridescence which makes it look blue.

Riskin: But iridescence isn't sparkly.

It almost looks like shiny paint on a car.

It is not sparkly like this spider.

Narrator: So the spider is not bioluminescent,

Iridescent or any other kind of -escent.

Time to go back to basics.

Burke: So a really important thing to do is work out

What species we're looking at if we can,

And we know that this is a wolf spider.

Narrator: Like many arachnids, the wolf spider has eight eyes,

But it's recognizable for this face --

Two large eyes at the front,

A row of four underneath and two hidden on top.

They are one of only a handful of spider families

That don't weave webs,

And the wolf spider has another unusual characteristic.

One of the remarkable things about wolf spiders

Is they're one of the few species of spiders

That show maternal behavior.

People think of spiders as these cold-blooded, unfeeling,

Terrible creatures.

They're not. They can be great mothers.

Wolf spiders carry their eggs around in a special silk sack,

And when those eggs hatch out, the spiderlings actually

Climb onto and completely coat the female's abdomen,

And they'll ride on her back like that

Until they're old enough to fend for themselves.

Narrator: It's cute, I think.

So that's a horror movie if you're scared of spiders.

Narrator: So could these petite piggybackers

Help us crack the case?

Wolf spiders are very visual predators.

They actually actively pursue their prey,

And they need really great eyesight to do this.

Narrator: Most spiders have poor eyesight.

They rely on web vibrations to know that prey has been snared,

But with no web,

Wolf spiders need perfect vision to hunt with.

They've evolved eyes that see particularly well in low light,

And it's this feature that illuminates the secret

Behind the sparkle.

So you see this in a lot of cats where they have eyeshine,

And basically there's a part inside the eyeball

That reflects extra light so that in dim situations

Enough light hits the brain that it can see something,

And you see this in a lot of nocturnal creatures,

Like crocodiles.

It happens in spiders, too.

Schreiber: So what we're in fact seeing

Are hundreds of tiny baby spider eyeballs,

All looking up at this lady and the torch.

Narrator: With one wolf spider mom carrying around 100 babies,

That could be 800 eyes and one brilliant answer

Staring us right in the face.

That's amazing.

♪

Narrator: Gansbaai, south africa,

Home to the most feared animal on the planet.

Huge teeth, incredible jaws.

Burke: They are supreme predators.

They are powerful, scary. They're fast.

They're precise.

They have incredible weaponry.

Midcap: They'll float just a little bit below the surface.

When they see something that they think might be food,

They increase their speed momentarily and kind of ram it,

Kind of maybe catch it off guard.

Narrator: The great white shark is considered

To be the ocean's undisputed champion predator.

But when, in 2017,

Their bodies began washing up on a south african beach,

It put that title in doubt.

We often think about great whites

As being these invincible, powerful hunters,

And so when four of them wash ashore dead on a beach,

Clearly having been killed by something else,

It really makes us wonder

What could have possibly happened to them.

Narrator: Local shark experts

Have never seen anything like this before.

They hope that an autopsy might tell them how the sharks died.

So what kills a great white shark?

♪

Narrator: The bodies of four great white sharks

Wash up on a beach in south africa.

This is a very rare event.

So what or who has killed them?

Humans in their boats kill all kinds of animals every year,

And it's very possible that one of them

Might have bumped into these sharks and caused them to die.

Narrator: But there's something about the sharks' injuries

That doesn't quite add up.

What's interesting about this kill is that,

When you look at it, it looks premeditated.

It looks surgical.

These sharks aren't just dead. They've been dissected,

And something has opened them up in a really precise way.

These sorts of injuries are just not consistent

With an accidental boat strike.

Even an intentional boat strike

Could not produce these kinds of injuries.

Narrator: If this wasn't a boat strike,

Could humans still be the killers?

Riskin: Humans kill sharks all the time,

But when humans are killing sharks,

They're usually doing it to take the fins.

Narrator: In china, they're used to make shark fin soup.

These carcasses all had their fins intact.

However, what they were missing were their livers,

Which had been almost surgically removed with such precision.

Narrator: Sharks' livers can make up

A quarter of their body weight.

They're packed with nutrients,

Which could be valuable to humans.

Nosal: In the first part of the 20th century,

Sharks were actually being hunted for their livers.

Shark liver oil is very rich in vitamin a,

But in the mid-1940s,

Scientists came up with a synthetic form of vitamin a

That eliminated the demand for shark liver oil.

Narrator: So if we're not hunting them

For their livers or fins,

Could another fish be the great shark killer?

Sharks kill other sharks all the time.

That's a normal shark thing.

Big fish eat the little fish.

Man #2: Oh! Oh [bleep]

Oh, my god. That is [bleep]

Narrator: This is very rare footage

Of a shark-on-shark attack off the coast of australia in 2014.

So was it cannibalism by other great whites?

Now, if these were sharks targeting other sharks,

What we would expect to see were teeth marks

From these serrated teeth that the shark have.

Narrator: A shark's jaggedy teeth

Leave an instantly recognizable pattern.

Burke: But this is not what we were seeing.

What we're seeing are teeth marks from a blunt tooth,

Like a blunt instrument.

Nosal: The kind of teeth marks we see

Are almost something mammal-like.

Narrator: These puncture wounds might be a huge clue.

Could they lead to the identity of the real killer?

Narrator: In 2017, four great white sharks wash ashore

In gansbaai, south africa.

Their injuries point to a series of savage attacks,

The likes of which have never been seen before

On this formidable predator.

Experts have found humans and cannibal sharks not guilty.

Now their attention turns to other suspects.

Riskin: There aren't a lot of animals that will eat

A great white shark or even part of a great white shark.

They're very hard to kill.

Dolphins sometimes get together to fend off a shark

And send it away, but they don't kill it.

Narrator: There is a sea creature that's been known

To tackle other large prey.

And that is a killer whale, an orca.

Orcas have the ability to take any size prey,

From something as small as a penguin

To something moderate in between, a seal, a sea lion.

They'll even take down a newborn blue whale.

Conley: Typically orca whales target mammals,

So it's possible that these guys are actually

Going after these sharks as well.

So could an orca

Really take down a great white shark?

Narrator: And there's another huge clue

The puts orcas right in the frame.

Conley: These guys have been known to go after whales,

And when they do, they just take the organs out,

And they leave the carcass floating in the water.

Narrator: Orcas only eat

The most nutritious parts of their prey.

The rest is clearly not worth the effort.

But tackling a whale for its organs is one thing.

A great white is something else altogether.

At the university of california at san diego,

Marine biologist andrew nosal is researching shark behavior.

He thinks the orcas might have picked up

On a key vulnerability in sharks.

This involves flipping them over on their backs

To put them into a temporary state of hypnotic inactivity

Known as tonic immobility.

By taking the shark and putting it on its back,

The shark's muscles go limp.

Its blood pressure and heart rate decrease,

And its breathing becomes deep and rhythmic.

The shark is in a very relaxed state.

In the wild, the shark doesn't typically enter this state

Of tonic immobility.

Imagine how easy it would be for another predator to come

And get it if it was just relaxed on its back.

Narrator: Is this what happened in south africa?

Orcas are smart, but are they smart enough to flip a shark?

Nosal: The orca would have had to have seized each great white,

Probably grabbing it by a pectoral fin or its dorsal fin,

Rotating it so that its belly was facing it up,

And then keeping it, holding it in that position

Long enough to induce tonic immobility.

Narrator: Now, just take a careful look

At this amazing piece of footage,

Shot off california in 2016.

Three orcas, one has a 10-foot-long

Sevengill shark in its jaws,

And the shark is clearly on its back.

It seems they've discovered andrew's shark immobility trick.

So is it possible that the orcas in south africa

Have learned to do the same thing

But with a much bigger shark like the great white?

Narrator: If so, who are the culprits?

Local shark experts have identified two orcas

In the area where the sharks were killed.

They give them the nicknames port and starboard

Because they share a very distinctive feature.

These two orcas are also very easily identifiable

Because they had dorsal fins that were both bent over.

Narrator: It's those fins that might explain

Why the dead sharks' livers were missing.

Nosal: Sometimes that's an indication

That the whales are stressed or malnourished in some way,

And so maybe that's why

They're targeting these high-nutrient livers.

Woman #2: Wow.

Narrator: All the evidence suggests these two orcas

Used an ingenious shark-flipping trick to kill four great whites.

Case solved.

Summer 2018, and in winston-salem in the carolinas,

A mystery has arrived on the doorstep.

So a north carolina resident wakes up one morning,

And as he opens his door, he notices there's more

Than just the one normal newspaper that he gets.

There's a few.

Narrator: For resident james eubanks,

It was quite perplexing.

Eubanks: I was looking out of our picture window,

Which overlooks the back,

And there were, like, five or six newspapers.

We had received ours that morning.

And then the next day he opens up the door again,

And there's more newspapers, and it keeps piling up.

He's thinking, "what is going on here?"

Now, we've picked up as many as 10 papers in one night.

Narrator: 10 papers a day?

No one likes the news that much.

Could the special delivery be from a local animal?

James decided to try and catch the prankster red-handed.

So james set up a motion-sensing camera in his backyard

To find out who the culprit was.

Narrator: The footage reveals many animal suspects --

An opossum, a raccoon, a bat,

But none of them is carrying the damning evidence.

The perpetrator is a little more sly.

It's foxes, groups of foxes just keep coming to his door

Mysteriously with newspapers in their mouth,

Leaving them and going away.

Without the pictures, no one would believe it.

It clearly shows him with a newspaper.

They don't do this kind of domesticated thing like a dog.

You'd expect a dog to be bringing newspapers.

That solved the mystery of who but not why.

Narrator: Up to 10 newspapers a day

Are being dumped in a yard in north carolina.

The mystery behind who's doing the deliveries is solved

When the culprits are caught on camera.

Foxes have lived up close with humans

All across north america and europe for a long time,

But why would a bunch of foxes want to deliver the news?

What's motivating this behavior?

Could it be a domesticated fox?

Burke: Certainly there have been plenty of examples of people

Feeding foxes, encouraging them into their gardens.

And certainly foxes can get very habituated,

Very used to be people,

But a pet fox that would be trained to deliver newspapers,

Now, is that possible?

Narrator: In some parts of the world,

Foxes are kept as pets,

And the wily creatures do seem capable

Of following instructions.

This one is riding the moscow subway.

I hope it got itself a ticket.

But we're talking russia here.

We're not talking north carolina,

A place where it is illegal to own a fox.

Narrator: So if these foxes aren't pets,

Why aren't they afraid of humans?

And why are they playing their own game of fetch?

Burke: Fox populations that live in and around

Urban and suburban areas are much, much more curious

Than their sort of rural counterparts.

What they need to do is lose something called neophobia,

Which is a fear of new things.

They tend to be much more risk-taking,

And they will explore new items.

Narrator: These foxes are certainly not afraid

Of new stuff.

Maybe they're just goofing around.

Cooke: Foxes are known to be playful,

As you can see from this one

Which was filmed playing with a dog toy

In a backyard in canada.

It's a bit less fun for the toy's owner though.

[ barking ]

Certainly with the young, with cubs and the juveniles,

Exploring and play is such an important part

Of their learning experience.

It's how they learn to socialize,

How they learn to interact with each other,

How they establish their hierarchies,

But most importantly, it's how they learn to find food.

They're probably testing just their ability to bite

Around an object and deliver it into one place,

And they got excited by that.

We're watching three scientist foxes repeat an experiment.

Narrator: But james eubanks has another theory.

Since it's newspapers, it must be fox news.