Nature (1982–…): Season 36, Episode 14 - Natural Born Rebels: Survival - full transcript

♪♪

All animals face
the same challenge.

They must find a
way to stay alive.

And in a tough world...

that's never easy.

So to get what they want,

some animals will
break all the rules.

Meet the planet's
greatest rebels.

They'll steal...

deceive...

and even resort to brute force.



These wild rebels
are getting to grips

with our urban world
in surprising ways.

But could behaving like this

actually be the secret
to their success?

We'll reveal new discoveries
and astonishing science

as our rebels strive to
outwit their enemies...

and get ahead in
the fight for survival.

♪♪

♪♪

Every day, animals across the
world face immense challenges.

Especially when our
world collides with theirs.

♪♪

In the land down under lives
a member of the parrot family...

the sulfur-crested cockatoo.



And as they get to grips
with the urban world,

these birds appear to be going
on a rampage across Sydney.

Destroying property...

annoying the neighbors...

loitering...

and even breaking
and entering...

The residents in this suburb
are reporting these rebels

are also turning up on a
particular day each week.

♪♪

Garbage day.

And they've been covering
the streets with trash.

So what are these
feathered felons up to?

In this area, the red bin is
for food and general waste

and yellow is for recycling.

♪♪

They're definitely curious.

♪♪

It's clear the cockatoos
aren't interested

in the yellow bin at all.

They're deliberately
rifling through the red bin...

The one that gets
them a free meal.

So there's a good
reason for all this littering.

But how have they
worked this out?

Scientist John Martin has
been working with cockatoos

for six years, carrying
out experiments

and fitting them with wing-tags
to monitor what they get up to.

What we're seeing
here is an example

of how cockatoos have
adapted to the urban environment.

After a bit of grabbing the
bin and moving it around

and then seeing
that the lid opens,

they did flip the lid open.

They did find the food reward.

Other birds then
copied that behavior,

and that information will be
mimicked by other cockatoos.

Information is being shared,

and that's benefiting
all the birds in that group.

The cockatoo's ability
to solve problems

and then share the solution

is a very smart
strategy for survival.

In fact parrots are amongst
the cleverest birds on the planet.

Some species have
even displayed intelligence

comparable to that
of a four-year-old child.

This brain power, combined
with a built-in inquisitive nature,

is what scientists
think is behind

all this outrageous behavior.

To survive in a
different environment,

animals, like cockatoos,

need to work out
what benefits them,

and that includes
new food sources.

So that explains the littering.

But what about the cockatoo's
reputation for casual vandalism?

♪♪

No. Oi, Stop it.

Some birds have
developed a habit

of attacking wooden balconies.

This has all been
done by the cockatoos.

What they do is just peel
pieces away, bit by bit.

Sometimes they
get over enthusiastic

and try to tunnel through
the entire piece in one go.

So, what is all this
destruction in aid of?

In their forest home,

Cockatoos regularly chew
on trees and branches.

It helps keep their beaks sharp,

and it's where they find
bugs and grubs to eat.

Cockatoos are now using
these same techniques

in our urban world,

investigating man-made objects

to find out if they
might be useful.

And with a bite four
times stronger than ours,

this trial and error is
causing extensive damage.

So, while the people of
Sydney may see all this

as a cockatoo crime wave...

the birds are simply combining

their natural
skills and abilities

to make the most of
life in their new home.

In the urban environment,

we often talk about
winners and losers.

Sulfur-crested
cockatoos are winners,

they're a successful species
because they're adaptive.

They're willing to take
risks and try new things,

they're exploring novel objects,

and they're finding food
resources and habitat

in the urban environment
where they didn't formally occur.

♪♪

For these cockatoos, city
living is working out well.

♪♪

♪♪

They're clever,
resourceful birds

with a curious and
exploratory nature...

and these are
exactly the qualities

that have led them to
succeed in this up-town world.

♪♪

♪♪

Just like the cockatoos,
rebels across the world

are known to cause
mayhem and mischief.

♪♪

But there's always a reason
for their outlandish behavior

in our urban environment.

♪♪

South African Penguins
take a fancy to beachwear

and use it to
feather their nests.

♪♪

North American black
bears break into backyards...

Standing in the
hammock's not a good idea.

Oh, dear.

Where new climbing techniques

and swimming lessons
are important life skills.

From an elephant
seal dealing with

an unusual threat
to his territory...

to polar bears looking
a little too close to home

for their next meal...

there's a survival strategy

behind all these
shocking animal actions.

♪♪

And some animals
will do whatever it takes

to get ahead in a
new environment.

♪♪

Amongst the trees and
forests of central Europe

lives a secretive species...

The stone marten.

These small omnivores are
relatives of otters and weasels.

Holding territories
within the woods,

they'll eat anything
they can find.

They hunt small
birds and rodents...

and forage for
fruit and berries.

♪♪

But some have realized there's
one place that's much easier

to find all the food, shelter,
and warmth they need...

♪♪

The city.

So martens are moving in
in ever-increasing numbers.

But now they're in town,

these rebels are
causing trouble.

♪♪

One morning, I got
into my car and drove,

and then suddenly,
the brakes didn't work.

When I opened
the hood of the car,

I saw that even the
caps were chewed on.

City stone martens
have developed

a new, alarming obsession.

We have stone-marten
damaged cars...

Two or three a day.

You see scratches
everywhere, little scratches.

You see here, the tubes
have been completely cut off.

And they are afraid of nothing.

♪♪

These vehicle vandals have
made headlines across Europe.

♪♪

They've become prime
suspects for electrical fires...

and they're been caught
red-handed by mechanics.

♪♪

Stone martens are
causing a staggering

$75 million worth of damage
every year in Germany alone.

♪♪

Severed electrical cables
and gnawed insulation

isn't just a nuisance...

It's a very dangerous problem...

and one that scientist Jan
Herr has been looking into.

So, we knew that martens went
into cars and damaged them.

What we really wanted to
know is why do they do this.

First of all, we saw very
big difference in behavior

between winter and
then spring seasons.

In spring, suddenly,
you find that the animals

spend an awful lot
of time in the road,

and they really start
running from car to car,

checking them out,

sniffing around on
them, climbing into them.

And that is the
same time of the year

where you get a lot
more car damage, as well.

♪♪

For a stone marten,
spring and early summer

is a very important
time of the year.

It's the breeding season.

Jan's research suggests
their destructive behavior

may all be connected by
the need to secure a mate.

Martens are very
territorial animals,

and males will
defend their territories

in order to have exclusive
access to females.

Like most carnivores,
stone martens

defend their territories
by scent marking.

So, they use two techniques.

Either they use
urine to scent mark,

or they can also
use small droppings.

♪♪

An intruder will try to
move in on another marten

by leaving its own scent
marks in his territory.

This can provoke
a furious response

from the original owner.

We're pretty sure
that there's a link

with territoriality.

So, once they're in
an engine compartment

and they come across a
scent from a different marten,

that they will have an
aggressive response,

they start biting
around on certain parts.

So, all this damage
might be caused by

a stone marten on the offensive.

But why do they only attack cars

and nothing else
in their territories?

In other environments,
they would just scent mark

rocks or trees or whatever.

At some point, they were
starting scent marking cars,

and cars are mobile
features in their environment

and they tend to move around,

so the cars carry
these scent marks

from territory to territory.

City residents are
moving their cars

between different
stone-marten territories,

and without realizing it,

they're totally confusing
the stone martens.

They can smell the
scent of a rival marten

on the new car in the area,

and they think
there's an intruder.

This sends them into
a scent-marking frenzy

as they attempt to
regain rightful ownership

of their patch,

and it's our cars
that pay the price.

But, of course, it's not
bad news for everyone.

Well, I find them very lovely,

but they bring us a lot of work.

As for the stone martens,

they'll always
defend their territory

to the best of
their abilities...

Regardless of anyone or
anything that gets in their way.

♪♪

These wild rebels
are getting to grips

with our urban world
in surprising ways.

But in the fight for survival,
there's a much bigger problem

that almost every
species must face...

predators.

Almost every animal
in the world has another

that wants to
eat it or just kill it.

♪♪

So one tiny crab in the Red Sea

has devised an almost
unbelievable strategy

to stay alive.

Beneath the waves,

amongst the corals,

lives an extraordinary creature.

A sporting super star...

the boxer crab.

♪♪

In a world where almost
everything is big and dangerous,

a tiny crustacean needs a
fool-proof plan to stay alive.

♪♪

This puffer fish fancies his
chances of an easy meal...

♪♪

But the crab has
a secret weapon...

the perfect pair
of boxing gloves.

♪♪

A blistering left hook
makes this fish think again.

And that's because those
gloves are, in fact, sea anemones.

Tiny relatives of jellyfish,

they have a cocktail of powerful
toxins in their tiny tendrils.

Every time the
crab lands a punch...

the anemone
delivers a painful sting.

The puffer fish won't
try that again in a hurry.

But to survive,
this prize fighter

needs to keep its gloves
in perfect working order.

Scientists have discovered that
these anemones could grow up to

five times their current size
if left to their own devices.

♪♪

So, to keep them
small enough to hold,

the crab starves them,
stealing their food for itself.

Gripped tightly in
the crab's claws,

the anemones are hostages.

It's a ruthless but
ingenious defense.

Even so, the crab's not
completely out of harm's way.

These anemones have
only ever been found

living in boxer crab claws.

♪♪

Which means another rebel

will inevitably try to pinch
these precious possessions.

♪♪

In the struggle, the thief
steals one of the anemones.

But this crab's not down
for the count just yet.

It still has one anemone left...

and one is all it needs.

It rips the anemone in half.

But this doesn't kill it,

because, incredibly,

anemones can survive
being split in two.

In time, the boxer
crab will regrow

the perfect pair of gloves,

and it'll be ready to roll
with the punches once again.

♪♪

In this dangerous
underwater world,

the boxer crab has a sporting
playbook full of sneaky skills,

and it's helping it
survive against the odds.

♪♪

If some rebels have
found very effective ways

to defeat their enemies...

others just aren't
suited to confrontation.

♪♪

In the rainforests of Central
America lives a creature

that uses a very
different tactic to survive...

the three-toed sloth.

♪♪

Sloth by name
and sloth by nature,

with a top speed of
around one mile per hour.

They're one of the slowest
mammals on the planet.

Yet this lethargic lifestyle

gives the sloth a big problem.

These rainforests are
full of impressive hunters...

from huge harpy
eagles to deadly jaguars.

♪♪

To protect itself,

this rebel is
using a dirty trick.

♪♪

Rain forests are clammy,
sticky, humid places...

Perfect conditions for
mold and fungi to thrive.

And, because they
don't move very quickly,

algae will even
grow on a sloth's fur...

turning them a delightful
shade of "rainforest green."

But what's really interesting

is that each hair follicle has
deep grooves and cracks,

which actively encourage
this algae to establish.

But why would they want
such a disgusting coat?

Well, the sloth's fetid fur
may act as camouflage...

helping to hide
them from predators.

But this living
green coat of algae

needs extra nutrients
to really flourish,

and it gets those from
a surprising source.

Sloth fur is full of insects...

Hundreds of them.

And one species in particular

is a moth that can only
be found on sloth fur.

This writhing, scuttling
mass of moths,

is vital to the sloth's
green camouflage

because the dead
moths and their droppings

provide the nutrients
for the algae to grow.

And while it might
seem revolting,

the sloth has actually
adapted its whole lifestyle

to make sure its fur is
teeming with these insects.

Once a week, three-toed
sloths make a perilous journey

down to the forest floor...

for a trip to the bathroom.

No other tree-dwelling
animal does this,

and it puts them at
great risk of predators.

♪♪

Why do they do it?

Once again, it's those moths.

♪♪

When the sloth is on the ground,

female moths hop off and
lay their eggs in its feces.

The larvae then feed here,
before they change into moths

and find another
sloth to live on.

♪♪

The sloth risks everything to
complete the moth's life cycle.

And in turn, the moths provide

the fertilizer for
the algae in the fur,

vital for the sloth's
camouflage and survival.

♪♪

So, they may be slow and
have questionable hygiene,

but the three-toed sloth has
devised an incredible solution

to stay alive.

♪♪

Some wild rebels take
camouflage to a whole new level.

There's the hawk
moth caterpillar

that looks like a snake,

a stick insect that
pretends to be a plant,

a leafy sea dragon
sways in the kelp,

and a leaf tailed
gecko disappears

against the trunk of the tree.

These extraordinary animals
have adapted their whole bodies

to hide in plain sight
and con their enemies.

♪♪

But when it comes to survival,

even one of the world's
most dangerous predators

uses a devious deception to
avoid becoming prey themselves.

♪♪

This is the home of a snake
with a truly terrifying skill set.

♪♪

The puff adder.

♪♪

With an attack speed of
just a quarter of a second,

armed with a cocktail
of cell-destroying venom,

hidden by cryptic camouflage,

and tracking prey with
a superb sense of smell,

this rebel is the
ultimate hunter.

♪♪

But even the puff adder
is not without its problems.

Surprisingly, this
venomous villain

has over 40 different
predators of its own,

including the feisty mongoose

and the fearsome honey badger.

♪♪

So, to continue
its reign of terror,

it must avoid
being eaten itself.

And to do that, it has
a very devious trick.

A team from Wits
University in South Africa

recently made an
extraordinary discovery

on their camera traps.

A genet walks straight
past a puff adder

and a porcupine
treads right on it.

These animals use
their sense of smell

to find food and locate danger.

Even in the dark, they
should sniff out the snake.

How is the devious puff
adder deceiving them?

♪♪

To find out, the research team

has its own devious,
innovative plan.

They've enlisted the help...

of a meerkat.

♪♪

Using an exceptional
sense of smell,

meerkats find and
attack a very daring diet...

including venomous snakes.

They're the perfect
scent detectives.

♪♪

First, scent samples
are carefully collected

from different snakes

and then placed in small tubes.

One tube contains
a control scent.

It's the smell of a
sterilized, empty tank.

The meerkats will be
given a food reward

if they manage to
recognize a specific scent.

Time to begin.

Right now, I'm
showing the meerkat

what she's looking for.

In this tube is the scent
sample of a brown house snake.

To the meerkat, this will
have a distinctive smell.

Now to find the matching
odor in the tube line up.

♪♪

There she's got it —
Brown house snake.

It now needs to find
the matching tube

for the puff adder scent.

But this time, it
doesn't seem so easy.

So, now she's
indicating the control,

which means she
can smell the tank.

The empty tank pretty
much smells of nothing.

And she continues searching.

She's also
indicating puff adder,

which means she
can't tell them apart.

By choosing both scent tubes,

the meerkat is showing
it can't distinguish

between the smell of the
snake and the empty tank.

It's as if the puff adder
has no scent at all.

So, this is a form
of chemical crypsis.

They're camouflaging themselves.

This discovery is extraordinary.

The puff adder has evolved

a kind of invisibility
cloak for its smell.

This allows them
to continue hunting

and still stay safe
from predators.

It's the first land
vertebrate known

to use this disguise
for its own defense.

♪♪

But just how it does
it is still a mystery.

♪♪

The puff adder has completely
nailed the art of survival.

From fatal fangs to
masterful deception,

this is one devious
snake in the grass.

♪♪

Hiding in plain sight is the
perfect way to avoid predators.

But other animals need
to be far more ruthless.

They'll even turn on their
own kind to stay alive.

On the seashore,
hidden in rock pools,

live tiny animals with huge
challenges to overcome.

Hermit crabs.

Unlike almost all
other crabs in the world,

the hermit crab doesn't
produce its own external armor.

To protect itself
from predators,

it has to pick a
shell to live in.

But the hermit crab is
constantly outgrowing its home,

and finding the right
new shell on a vast beach

can be a real issue.

So it has a lawless
plan to get what it needs.

♪♪

Another hermit crab...

and it has the perfect sized
shell for our growing crab.

♪♪

There's only one thing to do.

Fight for it.

♪♪

But brute force isn't enough.

To win, the crab
needs a new tactic.

♪♪

Using its own shell as a weapon,

it attacks the resident owner.

♪♪

And the faster it raps,

the more it's proving
its strength and stamina.

It's deliberate intimidation.

Cowering inside, the
victim tries to hold on.

♪♪

But our attacker has one
final devastating move.

♪♪

It's a forceful eviction...

that leaves the
loser homeless...

and the victor with
the shell it wanted.

This maybe blatant theft,

but the hermit crab's
aggressive strategy pays off.

It's found an ingenious way
to ensure its own survival.

So, animals will
do whatever it takes

to outwit their
enemies and stay alive.

But what if the
threat to survival

comes from closer to home?

From your own relatives?

Just off the coast
of South America,

one bird of prey
rules the roost.

The striated caracara,

also known as the Johnny rook.

♪♪

In spring, these birds
feast on the eggs and chicks

of the island's vast
seabird colonies.

For caracaras, these
are prime feeding grounds.

Each adult has carved out its
own territory in which to hunt.

And there's no space
left for anyone else.

♪♪

This juvenile has been
left on the sidelines.

Still too young to
have its own territory,

there's little access
to the hunting grounds.

♪♪

But a youngster
decides to chance its luck.

The adults take
down any trespassers.

♪♪

♪♪

♪♪

The risk of injury in
these brutal confrontations

is too high.

Outwitting the adults
requires a new plan.

Up on the moorlands,

the young caracara
isn't the only one in exile.

New science shows
juvenile caracaras

use distinctive calls
to rally together.

♪♪

This gang of teenagers
are planning a rebellion.

♪♪

Working together, they invade
an adult's feeding territory.

The balance of power shifts.

The adults can't fend
off the entire mob.

♪♪

♪♪

Their smash-and-grab
scheme has paid off.

Gorged with food,

these young birds
return to the moorlands.

Being forced to live on
the periphery is tough,

but for now, rising
up against the adults

is the only way to survive.

♪♪

Forming a gang helps
the young caracaras

get through their
tricky teenage years.

♪♪

But other animals
benefit by working together

throughout their lives.

♪♪

Even when you live in a
group, the best place to be

is usually at the
top of the hierarchy.

But to become the
dominant animal

takes clever, cunning, and
sometimes shocking tactics.

♪♪

Deep in the African jungle...

chimpanzees live together
in large social groups.

Their day-to-day lives
are relatively harmonious.

♪♪

But every now and then,
the peace is broken...

♪♪

By the alpha male.

♪♪

He will scream, display,

and fight to maintain
his position of power.

In Tanzania's
Gombe National Park,

scientist Michael Wilson
has been investigating

why alpha males use
such aggressive strategies

in their fight for leadership.

For the most part,
chimpanzees are

a bit nervous around
the alpha male,

and the other males
are pretty much

always jockeying for position.

And the alpha male does his
best to convince all the other males

that he's the one they
shouldn't mess with.

He's powerful. He's magnificent.

He may charge down
a path through the forest

and kick on a tree to make
a big booming buttress bang.

These lawless tactics
secure his status.

And crucially, this gives him
access to the perks of the job.

The main thing that an
alpha male chimpanzee

is concerned with
is making sure that

he gets to be the first one
to mate with fertile females,

and that's really
what his focus is.

While it's often been
assumed that the alpha male

will care for and protect the
chimpanzees in his group,

the latest thinking suggests
these dominant males

are only in it for themselves.

Using selfish and
aggressive tactics

gives alpha males
the best opportunity

to have as many
offspring as possible.

But over the years,
researchers have reported

some rebel alphas
with a level of brutality

that seems unusually
high, even for chimps.

♪♪

So, can individuals
have distinct

and even sinister personalities?

One alpha, who reigned
here back in 1997, was Frodo.

♪♪

Footage from the time shows
how he maintained his position

through a terrifying combination
of intimidation and violence.

He bullied the other males,
he bullied the females,

he bullied the people

who were trying to
follow the chimpanzees.

We were all afraid of him.

♪♪

Frodo was a ferocious fighter

during attacks on other
chimpanzee groups,

and that aggression spilled
over to anyone in his way.

When I first got
here, he followed me,

and he just knocked
me into the bushes

and hit me with his fists.

It makes a really
good spectacle.

It shows all the other
chimps he was magnificent.

The next time I was
in the forest with Frodo,

I was really nervous.

Which I think is
what life is like

for most chimpanzees
most of the time,

"Where's the alpha
male? Is he gonna hurt me?

Is he gonna beat me up?"

Frodo's behavior was extreme.

His attacks often seemed
malicious and unprovoked.

It was as if he was being
mean simply because he could.

Frodo was just so
big and powerful

that he didn't seem to
need anyone else's help.

Normally, with chimpanzees,
there's a lot of reciprocity.

It's, "I groom you,
you groom me."

"You scratch my
back, I'll scratch yours."

With Frodo it was just,
"You scratch my back."

Frodo held the alpha
position for five years

before becoming ill.

With eight offspring, he was
the second-most successful male

in Gombe history,

and he was by
far the most brutal.

If a person acted similarly,

some scientists might consider
them to be a psychopath.

Roughly 1% of humans
show psychopathic traits...

Characterized by the lack
of morals and empathy,

with fearlessness, ruthlessness,
and volatile aggression.

New research is
revealing that, like us,

individual chimpanzees do
have distinct personalities,

and so some may be more
inherently violent than others.

It can be shocking
to see chimpanzees

attacking and killing
each other like this,

and we tend to see
chimpanzee behavior

in very moralistic terms

because they look and
act so much like people.

But if we think
about it in terms of

what chimpanzees need to do
to succeed in their environment,

this is one way of
achieving that goal,

and it looks to be a
very successful strategy

for chimpanzees.

♪♪

For alpha-male chimpanzees,

being a bully comes
with the territory.

These rebels are doing
whatever they need to do

to get the greatest reward
when it comes to survival.

♪♪

♪♪

When the struggle to stay
alive is a constant battle,

it's no wonder animals
will turn to devious tactics.

Oi. Stop it.

Whether it's a cockatoo
with a taste for vandalism...

No.

A crab holding
anemones hostage...

or even the horrible
hygiene of a three-toed sloth...

these rebels will go
to remarkable lengths...

in the drive to survive.

♪♪

Next time, we meet
nature's love rats.

The sneaks...

cheats...

and the downright freaks.

Doing whatever it takes

to find a mate

and bring up baby.

♪♪

♪♪