All language subtitles for Natures.Strangest.Mysteries.Solved.Series.1.09of10.Animal.Vandals

Narrator: How and why did ants
build this bridge

With their own bodies?

Daly: The level of cooperation
it takes to pull this off

Is mind-blowing.

Narrator: And, no joke,
why did the fish cross the road?

Most fish would never do that.

Narrator: And what creature is
behind a european crime wave?

These animals caused
$330 million

Worth of damage to cars.

The big question is -- why?

Narrator: Nature is
awe-inspiring.

But sometimes,
it just doesn't make sense.

Man: I have never seen
anything like this.

Our team of experts
investigate

The weirdest
animal behavior...

That's amazing.

...And the most unexpected
events...

What is causing that?

...Ever caught on camera.

Man #2: My god!

These are...

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

Captions paid for by
discovery communications

Luxembourg, 2016 --

Residents of this small
european country

Are waking up to
a curious crime wave.

Thousands of motorists
are finding their cars

Had been damaged
and won't start.

However, the evidence
is quite strange.

Not only are wires
cut through completely,

But there is feces and a strong
smell of urine everywhere.

It's not human vandals...

It's animals.

Very angry animals.

Narrator: It turns out
that stone martens,

A relative of
the american pine marten,

Have been engaging in an ongoing
campaign to destroy cars.

What may at first
seem like a minor act

Of wildlife vandalism
is in fact a very big deal.

Cooke: Between 2010 and 2014,

Stone martens caused
$330 million

Worth of damage to cars.

That's over a million
insurance claims.

The big question is -- why?

Narrator: To find out, we need
to know more about this furtive

And furry rascal.

So, what exactly
is a stone marten?

Greive: It's basically
a super weasel.

It's about the size
and weight of a house cat,

But far slimmer
and far more muscular,

And 10 times the mischief.

Narrator: In the last 40 years,

The stone marten population
in europe has exploded.

Cooke: So, back in the 1950s,

Stone martens
were almost extinct.

They'd been hunted
for their fur.

But now, populations
are bouncing back,

And they're actually
spilling into urban situations.

And that's where we're starting
to see this vandalism.

Narrator: However,
closer proximity to people

Still doesn't explain
why they're terrorizing cars.

And while the bad-boy behavior
seems strange,

It's not the first time members
of the animal kingdom

Have targeted motor vehicles.

Greive: There's a safari park
in mersey side, in England,

Where baboons are famous for
tearing off windshield wipers

Just to elicit a response
from the drivers within.

Man: [ laughs ]
dude.

Child: Look at the monkey!

No!
Woman: Go on!

Oh, no!

Ah [bleep]

[ laughter ]

Greive: And in the mountains
of new zealand,

There's a large alpine parrot
called a kia

That, curious as they are,

Is famous for tearing off
pieces of rubber,

Not just from
the windshield wipers.

But also from window seals
and sun roofs,

And even the tires themselves.

♪

Narrator: But what's driving
the stone marten

To carry out
this vehicular vandalism?

Greive: So, is this damage
caused by young stone

Martens who are basically
trying their new teeth out

On anything they can find?

Cooke:
Are they just chewing things,

Trying to figure out
how their teeth work

And what's good and what isn't?

Greive: A team of scientists
are currently

Looking into
what it is that stone

Martens are attracted to
within vehicles.

Narrator: We paid one of those
scientists a visit,

Britta habbe,
in hankensbuettel, germany.

Habbe: Stone martens cause
a lot of damage in germany.

Now we've got about 66 million
euros of damage per year.

Narrator: Habbe works
with captive stone

Martens to try to get
to the bottom

Of why they are wreaking
so much havoc.

We run different tests
to find out how to prevent cars

From being damaged
by stone martens.

We've put two animals in here.

They are called kate
and william.

Stone martens show exploring
behavior by gnawing on things.

They've got very sharp teeth,
and that's why they can cause

A lot of damage
on cables used in cars.

Narrator: So does habbe
think teething toddler

Martens are to blame?

We found out that young

Martens don't show
this kind of behavior.

At least, they have to be
two years old.

The young ones don't do that.

Narrator: Juvenile nibblers
are ruled out.

Could there be another reason
the stone

Martens go into the vehicles?

Cooke: What if the martens are
actually attracted to the cars

Because they think
it's a food source?

Well, incredibly, some car
cables actually

Have food substances in them.

So that could be attracting
the stone martens.

Narrator: Surprisingly, soy-
and plant-based sugars

Can be a major component
of some car cables.

And though cars now contain up
to about a mile of cable,

The stone marten isn't
a picky eater

When it comes
to which cables to chew.

He'll bite them all.

Studies have shown that
there's no material

That makes these wires
and cables more

Or less attractive
to a stone marten.

Any other substance doesn't seem
to make a difference.

So why are they chewing
through these cables?

♪

Narrator: Dr. Jan herr,
a zoologist in luxembourg,

Tracked wild stone martens
over a two-year period,

And thinks the answer may lie

In their highly
territorial behavior.

I equipped 13 stone martens
with a radio collar

That sends out a signal.

It helps you to follow
the animal around,

To locate its position.

I took a location of the animal
every 15 minutes, at night.

And it gives you a very
good definition

Of where the territory
of the animal is.

You can see that, different
colors for different martens,

So it's very clear
territorial behavior.

Narrator: What he discovered
is that the solitary male stone

Marten jealously guards
his home turf

By scent-marking objects
within it.

Now, you can imagine
that the stone marten

That has scent-marked
the car over here?

That car is gonna be driven away
to a different territory

Within the same town,
or a different town,

And that basically means
that this stone marten

Is gonna come across
a scent mark from a marten

That lives somewhere far away.

And that will obviously trigger
their territorial response.

Greive: We now know that these
vehicles were targeted simply

Because they are
unwitting participants

In an ongoing stone
marten turf war.

Narrator: Cars are routinely
scent-marked

By a stone marten
when parked in its territory.

When the car is moved
outside of that area,

It's marked by
another rival stone marten.

And when that vehicle
then returns home,

All hell breaks loose.

Greive: The original
stone martens will tear apart

Every aspect of that vehicle
that they can,

Trying to obliterate
the scent of their rivals.

And that's not enough for them.

Stone martens take it
one step too far

By defecating
throughout the vehicle,

To make it very clear
who it belongs to.

Narrator: The final insult
is ripping through the car's

Internal wiring
with their sharp teeth.

And given the size of a stone
marten's territory,

That means a lot of cars
are in the firing line.

Keep in mind, a stone-marten
home range is roughly 200 acres.

That's roughly 800 households.

Just assuming there's one
car per household,

That's 800 cars
for a stone marten to mark.

Narrator: And how are
european drivers

Dealing with this
vehicular vandal?

Well, one way is to send out
small electric shocks

That deter the martens.

Another is to use sound,
a very high-frequency sound,

That will put the martens off
from chewing the cables.

Greive: But of course, the only
truly effective measure

Is a paid-up
insurance policy.

♪

Narrator: Costa rica,

July 30, 2018 --

Extraordinary footage is
captured of an army

Ant structure.

Daly: When you first look at it,

It looks more like
a rope or a vine,

But upon closer inspection,
you can see thousands of ants.

Narrator: The colony
has joined forces

To create a living bridge.

I think that's amazing.

Daly: The level of cooperation

It takes to pull this off
is mind-blowing.

For an animal
with a brain smaller

Than a pin-head,
what they achieve is remarkable.

Narrator: But what motivated
this miniature feat

Of engineering?

Why have these ants built
such an incredible structure?

♪

Narrator: In costa rica,
army ants have constructed

A living bridge out of thousands
of their own bodies.

How?
And why?

To find out, we need to know
more about these mini marvels.

There are over 13,000
known species of ants.

Army ants are nomadic and have
some of the largest colonies,

Making them a moving swarm --

One that eats
almost everything in its path.

One single colony can be
comprised of millions of ants.

And within that colony,
they can consume

50,000 different
prey items per day.

Greive: The ants' strength
is entirely in numbers --

The ability
to overwhelm an enemy

With relentless
stinging and biting.

So, to a colony of army ants,

The entire planet
is a moveable feast.

And they are
absolutely relentless

In their pursuit of new prey.

Narrator: It's these qualities
that make them

The most voracious
predators in the rainforest.

On this occasion, the army
colony is raiding a wasp's nest,

Carrying off the wasp larvae
as a tasty treat.

But the route the army ants
have taken is a puzzling one.

Greive: They've taken a very
elaborate path.

Why wouldn't they just move
directly across the roof

And attack the nest at its base?

It seems like a lot more
trouble than it's worth.

♪

Narrator: It turns out
that the stalk of the nest,

Where it's fixed to the ceiling,

Is covered in a wasp-made
insecticide,

That only they are immune to.

Greive:
The wasps create a substance
which is quite toxic to ants,

And they coat the entire base
of their nest with it.

Narrator: But instead
of calling it quits,

The army ants build
this living bridge

To circumnavigate the poison.

But how do ants dream up
these elaborate structures?

To find out,
we met with scientists

Who have been studying
ant super powers.

Working with ants
is always surprising.

We always underestimate
what they can do.

Narrator: Case in point --
ant strength.

While we've always known

They are the heavyweight
champions of the insect world,

It's only recently been revealed
just how much muscle they have.

Hu:
Ants are tremendously strong.

We know that they can carry 10

To almost 100 times
their weight,

But their exoskeleton
is much stronger.

It can take out 100,000 times
an ant's body weight.

That's the equivalent of us
being crushed by a house

And still be able
to walk away.

Narrator: But it's the swarm
intelligence of ants

That makes them
such amazing architects.

They don't just build bridges.

When they encounter water,

They make a spontaneous
floating device.

Instead of panicking,
they'll actually start linking

Their bodies together
and building this raft

That can float around
on the water's surface.

The ants on the bottom of this
raft you think would drown,

But each of these ants actually,
when they're together,

They can carry bubbles
with them,

Trapped between their legs.

So the ants on the bottom
are basically breathing.

Narrator: Ants breathe through
an opening in their abdomen

Called a spiracle, which
the bubble supplies with oxygen.

But when it comes
to bridge building,

It's the ant colony's team work
that is the defining factor.

Hu: Cooperation is vital

When they're building
these structures.

The ants had started out with
basically a single line of ants.

But there was a lot of interest
in going to this wasp nest,

So it recruited more
and more ants.

And so, the bridge
had to grow in width

To accommodate the traffic.

But because there's so much
traffic,

The bridge had to become
longer to support itself.

Burke: The solution is really
elegant and extraordinary.

These ants formed
this long length of chain,

On which other worker ants
can run back and forth.

Narrator: And by creating a long
path to get to the wasp nest,

The ants mount
a much more effective raid.

Greive: Thousands of ants
continue to fortify this,

Until we have active soldier
ants going in to fight the wasp.

And wave after wave of army ants
make their way into the nest,

Until they destroy
the wasp nest,

And then wave after wave
make their way out,

Carrying their booty.

Narrator: Proving that the
humble ant is not to be messed.

Daly: Individually, ants may be
fairly easy to overlook,

But once in a large group,
they are unstoppable.

Grieve:
Their ability to construct

Improvised architectural wonders
on the fly is without peer.

They're one the most
remarkable animals I know of.

♪

Narrator: November 2016,
skokomish, washington --

Something fishy is going on
on this flooded road.

Animals are using it
as an aquatic crosswalk.

Conley:
So, this a really cool video,

Where we see a flooded-out
highway and fish

Just scooting
their way across.

So, the question is -- why?

♪

Narrator: In skokomish,
washington,

Fish are crossing the road
to get to the other side.

Why?

♪

Nosal: Could these fish be
trying to find more space

On the other side?

Maybe things are getting
a little tight,

Food is getting
a little scarce on one side

And they're trying
to expand their range.

Narrator: If so, it wouldn't
be the first time.

Conley: There is some footage
of catfish crossing a road

In the kruger national park
in south africa,

Where you see this behavior.

These large fish
will come out of the water

And they'll go
somewhere else,

They'll try to find
a better habitat.

Narrator: Mudskippers are
another famously mobile fish

That can be found
in the indo-pacific,

From africa
through to australia.

Conley: Mudskippers, they can
actually move around

Outside of the water,
in order to find

More beneficial conditions
for themselves.

And they can survive
for quite a long time.

Narrator: In fact, for as long
as they can stay wet.

But the anatomy of catfish
and mudskippers

Differs from
the vast majority of fish.

Nosal: These species are
actually able to gulp air

And use it
for a period of time.

Most fish are not able
to do that.

So it seems unlikely that these
fish would actually be

Leaving water
to find another place.

Narrator: It looks like
these fish

Are not on
an exploratory mission.

It turns out that this is
an annual rite of passage.

And in fact, this phenomenon
seems to happen

At the same time
every single year.

Narrator: And there is
one species of fish

That will swim past
almost any obstacle

To get to where
they need to go --

Salmon.

♪

Salmon are born in fresh water,

Typically fairly far
from the ocean.

But as they grow, they will
swim down toward the coast.

What's amazing is, we don't know
a lot about their behavior

When they're out
in the middle of the ocean.

What we do know is that,

When it comes time for those
salmon to spawn themselves,

They find their way
back to the coast,

And then they'll migrate
their way

Through the branching rivers.

Narrator: In one of the most
stunning feats of nature,

Salmon swim up
to 2,000 miles upstream,

Leaping up to 12 feet
in the air,

To return to their exact place
origin to lay their own eggs.

But it takes more than
physical strength to get home.

They also have to
dodge predators

Who have staked out
their route.

Nosal: A very important
food source for bears,

For birds of prey.

Conley:
It becomes a feeding frenzy

For all the animals
in that environment.

Narrator: But for the salmon
that make it,

This remarkable life cycle
continues.

Once these migrating
salmon swim upstream

And find their natal stream,
they mate,

They give birth...

...And they die.

Narrator: But even after death,
this super species lives on.

Nosal: These salmon,

They form an important
part of the ecosystem.

They contribute so many
nutrients

To the surrounding water
that they're taken up

In the root systems
of nearby trees.

Narrator: In the great forests
of north america,

Up to 80% of the vital soil
nutrient nitrogen

Comes from salmon.

As such, salmon have been
named a keystone species,

Which means they are crucial
to the environment.

Nosal: So they are uniquely tied
to the rest of their ecosystem,

So it's very important
for us to protect

Not only
the spawning grounds

But the entire migration
route for these salmon.

Narrator: The mystery now is --
how did the skokomish salmon,

Who are just at the beginning
of their epic journey,

Even know where to go?

♪

Narrator: In skokomish,
washington,

Salmon are playing chicken
with the traffic.

It's part of their marathon
swim, thousand of miles upstream

To get back to their exact
place of birth to spawn.

But how do they even know
where to go?

By using a salmon sensory
super power.

Nosal: What's amazing is,
using some combination

Of geomagnetic
and chemical cues,

They'll actually find the stream
where they were born

Using the unique signal
of that water.

Narrator: So, for these salmon,

The road is
just another obstacle

In their miracle journey.

Nosal: It's possible that
this stream that they were

Traveling on happened
to have a road built over it.

Maybe there was a pipe

That normally allows water
to go through.

But if this stream
is overflowing

Because of a big rain event,

The salmon, instead of going
through the tunnel underneath,

Are gonna just go right on top.

Narrator: Proving that salmon
will do whatever it takes

To make it home.