All language subtitles for attenboroughs.life.in.colour.s01e02.1080p.bluray.x264-orbs[eztv.re]

SIR DAVID ATTENBOROUGH:
The natural world is full of colours

that we often take for granted.

There are few animals
more brilliantly colored

than these scarlet macaws.

Animals can use color
for all kinds of different reasons

and some have colours
that we ourselves can't even see.

But not all colours
are what they seem.

Some animals also use colours
to hide.

Colours that make them disappear.

Colours that create
optical illusions.

And colours that are used
to trick and deceive.

To understand how
these colours work,

we need to see them
from an animal's perspective.

With the help
of our specialist cameras,

we can now do that...

...and discover how some animals
have become masters of disguise.

The Indian subcontinent is home
to some truly spectacular animals.

PEAFOWL CALL

Most, like these peafowl,
use color to attract attention

and the kinds they've developed

are influenced by the way they see the world.

But flashy colours can
also come at a cost,

and sometimes it's better
to remain out of sight.

So some animals use their colours

to help them hide
and disappear into the background.

One such animal lives here
in the forests of central India.

It's one of the most formidable
hunters on earth.

A Bengal tiger. A female.

She's one of the world's
biggest cats,

and remaining out of sight
is not easy

when you are as large as she is.

Her orange and black coat
is crucial to her success.

To have any chance
of catching a meal,

she has to get to within
a few metres of her prey.

She keeps to the cover of the trees

and slowly makes her approach.

She may appear conspicuous
to our eyes,

but not so to these chiral deer.

Ch ital have only two types
of color receptors in their eyes,

compared to our three,

which means that they are
effectively blind to red and orange.

So to the deer,
the tiger isn't orange at all.

This is how we see the world...

...and this is how the deer do.

The tiger's orange coat to them
is a muted shade of green,

so it's nearly impossible
for the deer to register.

She creeps closer.

The chiral don't see her.

The odds appear stacked
in the tiger's favour.

But the deer aren't
entirely defenseless.

They have help from an unusual ally.

Languor monkeys.

They're known as
'the eyes of the forest'

and their color vision
is excellent.

Their eyes, like ours,
have three types of color receptors

and they CAN see orange.

MONKEY GROWLS

The languors sounded the alarm
before she could get close enough.

If the languors can easily spot her,

why then is the tiger orange at all?

Why isn't she green?

That's because mammals are unable
to develop green pigments,

so it seems the next best solution
for the tiger is to have orange fur,

which appears green
to her main prey.

She will have to find a new target.

Down by the water, she finds one -

samba deer.

Samar don't keep company
with monkeys.

They are on their own.

They have the same limited eyesight
as the chiral,

but ears like satellite dishes.

If she treads on a twig
and it snaps,

the hunt will be over
before it began.

The deer seem to sense danger.

They still can't see her.

Despite her effective camouflage,

most hunts end like this.

Less than 10% of her attacks
are successful.

But without her orange fur,
her chances would be even lower.

It is her colours that are key
to her survival.

The Cairn Mountains in Scotland.

Here there are special problems
for the hunted.

Some animals have developed
camouflage of such perfection

that they are virtually invisible
against their surroundings.

But what happens
when those surroundings change?

Well, then, of course,
the animals have to change too.

These mountains are home
to a particular kind of grouse

called the ptarmigan.

Their mottled brown feathers
make them inconspicuous

among the rocks and heather.

But in winter,

these mountains are hard places
in which to live.

Temperatures drop

and the land can overnight
be covered by a blanket of snow.

Most birds by now have gone south
to warmer parts of the world,

but not the ptarmigan.

When winter comes, they undergo
the most extraordinary change.

They replace their brown feathers
with pure white ones.

They do so for a simple reason -

they must go unnoticed.

They need to hide.

This open habitat
makes the ptarmigan

very vulnerable to predators.

Being the right color is crucial.

Now they are invisible
even to a keen-eyed eagle.

Ptarmigan are not the only animals
to use this disappearing act.

So does the arctic fox...

...snowshoe hares...

...and weasels.

All, with the coming of winter,
change their coats

and vanish from sight.

Their transformation is triggered
by the decreasing daylight,

and over several weeks,

they replace their brown costumes
with white ones.

So, changing color with the seasons,

for some animals,

is the only way to avoid
becoming a meal.

But many plants, of course,
do the reverse.

In spring, they produce color

to declare that are
providing food - nectar.

Bees and many other insects love it.

In spring and summer,

they travel busily from flower
to flower collecting it.

And when the bees leave
to look for more,

they inadvertently take pollen
with them,

which then fertilizes
the next flowers they visit.

But there's a hunter here
that exploits this relationship.

A crab spider.

She's tiny -
no bigger than a fingernail -

and she's waiting for her prey.

Almost the same color
as her background,

she's virtually invisible.

No more honey for her.

But of course, the spider's
hunting grounds are limited.

Not all flowers are yellow.

When she sits on a pure white petal,
she immediately becomes obvious.

She will never catch a bee
while she's so conspicuous.

So she changes.

She breaks down the yellow pigments
in the outer layer of her skin

to expose special crystals
underneath

that act like tiny mirrors
and reflect the light.

It may take a few days,

but she turns from yellow to white.

Changing color isn't
the spider's only trick.

There's more to this story
than meets the eye.

Bees can see colours that we cannot.

They can see ultraviolet colours.

As they come in to land on a flower,

they use special sensors that can
detect ultraviolet patterns

on the flower's petals.

We can see them too

with our special UV camera.

There are dark lines on the petals

that mark the landing strips
for the bees,

guiding them to the nectar.

The spider, however, has developed
a way to exploit these signals.

Watching her with our UV camera,

we can see that she reflects
ultraviolet light,

SO she appears even more conspicuous
sitting on a flower.

This extra brilliance
acts as a kind of super signal

which the bee can't resist.

And the spider benefits.

In fact, the bees are more than
three times as likely

to visit flowers
with UV-reflecting spiders on them

than those without.

The crab spider uses
a sophisticated range of colours

to deceive its prey.

But color can also be used in
a simpler, even more surprising way

to confuse the enemy.

And on the plains
of Kenya's Maasai Mara,

there's one animal
that uses just two colours

to outwit its predators.

The zebra.

Its black and white coat
makes it extremely obvious

as it grazes
out on the open grasslands.

Other grazers have softer,
gently varied coloration,

which blends with their background.

So, it seems strange that zebras
apparently do quite the opposite.

Particularly as they live in a world
where there are so many hunters.

Lions...

...hyenas...

...and cheetah.

The boldly-striped zebra
seem to be asking for trouble.

How do they get away with it?

The question has been hotly debated
by naturalists for centuries.

New research is now
suggesting an answer.

To understand how it might work,

we need to consider
the particular colours involved.

Black and white are two of
the most contrasting colours

and no two animals have
exactly the same pattern,

so each has a unique
whole-body fingerprint.

But when the zebras move,
the stripes create confusion.

It's known as motion dazzle...

...and it makes it difficult
for a predator

to keep focused
on one particular target.

The cheetah, looking for a meal.

To make a successful strike,

they must judge the distance accurately
and time it perfectly.

So if a zebra's stripes
can confuse the cheetah

just for a few crucial seconds,

it may escape.

ZEBRAS CALL

But there's another threat
on these plains.

BUZZING

Flies.

They are a real pest here.

They're not just a nuisance -
they carry diseases,

some of which are particularly nasty,
even deadly.

Despite the huge numbers of flies,

the zebras appear
remarkably untroubled by them.

There are plenty of flies around...

...but few actually land
on the zebra.

One theory is that
the black and white stripes

make it difficult for flies
to judge the distance.

To test this idea,

scientists counted
how many flies landed

on animals with
gently graded colours

and how many landed
on the zebra's stripes.

They found that four times fewer flies
landed on zebras

than on their more
plainly-colored neighbours.

Why should that be?

It seems it's another consequence
of those stripes.

They confuse the flies as they make
their final approach to settle.

Perhaps this creates
a visual blurring for the flies,

much as it does for a cheetah.

So, it seems that
the zebra's patterns of stripes

create an optical effect
that helps protect them

from enemies both large and small.

While zebras use different patterns
to confuse their enemies,

on the island of Cuba

there are smaller
and rather slower-moving creatures

that do a similar thing.

This is Polymath pica,

a Cuban painted snail.

You might think that this one is

an exceptionally lovely,
eye-catching individual.

But it's not by any means
the only snail

that is so beautifully decorated.

No two individuals are
exactly the same,

yet all these belong
to the same species.

There are also five other species
of Polymath here.

Each snail has
its own unique combination

of colours and stripes.

Their colours come from their diet -

lichen and mosses rich in minerals

that give the shells
these stunning colours.

They differ according to
the particular mix of plants

that each snail has been eating.

Variations of individuals
within a species

is not uncommon
in the natural world.

It's called polymorphism.

But it's particularly marked
among Cuban snails.

Some scientists believe
that the variation in itself

may be a kind of defense
against predators.

But how could that work?

Most animals looking for prey
have a search image in their minds.

They scan their surroundings

looking for a victim
that matches their expectations.

If they see something they recognise,
they'll go for it.

And that's where the snail's
varying colours may come in.

The great range of different
tints and patterns,

it seems, confuses the birds.

He's never seen one
quite like this before.

And while the bird is wondering
whether it's edible or not,

the snail can - slowly -
make a getaway.

So, it seems that color can
both conceal and confuse.

And sometimes it's used in yet
a third, quite different, way.

Some poisonous animals,

like this little ladybird,

use color as a warning.

It's bright red,

and that's a message which says,

"Keep away. I'm poisonous."

Red, black and yellow are
widely understood as warnings,

so the ladybird's message is
a truthful one -

it is poisonous.

But some animals
that are in fact harmless

have found it profitable to develop
these warning colours themselves.

This African queen butterfly,
like the ladybird,

is indeed very poisonous.

But this is
a different species entirely -

a Dana butterfly.

It has almost exactly
the same coloration,

yet it's perfectly edible.

It is, you might say,
using its colours and patterns

to tell a lie.

To our eyes
and to that of the predators,

poisonous and non-poisonous
individuals look almost identical -

and that's the point.

The Dana mimics the colours
and patterns of the African queen

and so it isn't eaten.

Mimicry like this occurs
quite frequently among insects.

The yellow and black stripes
of this harmless overfly

resemble the warning colours
of bees and wasps that sting,

so it's left alone.

Other animals use mimicry to hide.

This moth resembles a broken twig.

A kind of mantis closely matches
the shape and colours of a leaf.

Another mantis is shaped
and colored like a flower...

...and gets a reward
for the resemblance.

And one particular caterpillar
has come to look like a tiny snake.

While this butterfly's wings take on
the appearance of dead leaves.

But there are some animals
which use mimicry

for a rather more sinister purpose.

And one such creature lives here
on Australia's Great Barrier Reef.

Just beneath the surface,
the reef is a riot of color.

But that means there are great
opportunities for deceptions.

A blue striped Lenny.

It lives close to
a cleaning station -

a place on the reef
where large fish come

to get their parasites picked off
by smaller fish

that feed on what they remove.

This little wrasse
is one of these cleaners.

It has a longstanding relationship
that relies on trust.

The big fish get a health treatment

and the little fish get a meal.

But the Lenny has learn how to
exploit this trusting relationship.

It leaves its hole
and starts looking for a meal.

But the big fish
don't seem to trust it.

It's time for a change of costume.

Filmed close up
under controlled conditions,

we can see how the Lenny’s
brown stripes turn black.

The pigment cells in its skin
expand and contract

to bring about this subtle change.

But it's enough to do the trick.

The Lenny now looks very similar
to a juvenile cleaner wrasse.

It's a devious disguise

and one that will help it
take advantage of the arrangement

the cleaner wrasse has developed
with its clients.

It's spotted a target -

a butterflyfish.

The Lenny hangs back,

allowing an established
cleaner wrasse to start work.

Now the Lenny slowly moves in,

as if to offer the same service
as the wrasse.

But once within range...

...it strikes!

Its razor-sharp teeth have removed
not just dead skin

but a chunk of flesh.

This isn't the treatment
the butterflyfish was expecting.

The Lenny's deceit
may work for a time,

but eventually it has consequences.

Reef fish begin to associate

the distinctive colours
of a cleaner wrasse

with the pain of the bites
of a Lenny.

Then they will eventually stop
coming to this cleaning station.

And that is bad for business
for the Lenny too.

So it's time to let things cool off.

A quick change back to brown

and its deception is over - for now.

All the while, it keeps its eye
on the cleaning station

and waits for its next target.

Some animals change color
for short periods of time

in order to deceive others,

but some use color mimicry
permanently

as a method of persuading
a different species

to rear their young.

One such creature lives here on
the grasslands of southern Zambia.

A nest hidden in the grass.

It belongs to a pair
of common waybills.

They are busy feeding their chicks.

The hungry youngsters
open their beaks

to display
a conspicuously patterned gape

which says, in effect,
"Food here, please!”

And the parent obeys.

But among them, in this nest,
there is an impostor.

One is significantly bigger
than the rest.

It hatched from an egg

that was surreptitiously laid
in the waybills' nest

by a pin-tailed why.

Having done so, she flew away,

leaving her young to be cared for
by the waybills.

But why do the waybills
feed this impostor?

The parent birds
recognise their young

by the pattern of their gapes.

And the black and white markings
are characteristic of their species.

But the impostor's markings closely
mimic those of its nest-mates,

and because it's bigger,
it takes nearly all the food

and the young waybills
get little or none.

Two weeks later,

and the young why is much bigger.

By now, however,

the adult waybills have accepted
the young why as their own,

and the more it begs,
the more they give it.

One last meal from
its luckless foster-parents...

...and the young why
leaves its nest-mates behind.

And this is what
it will grow up to be -

quite different from the hardworking
waybills that raised it.

All pin-tailed howdahs
are reared like this.

Mimicry wins.

Deceiving a different species
is one thing,

but in South Africa, one animal
uses mimicry to fool its own kind.

The Orange River,
the largest in South Africa,

and on it, the Aug rabies Falls.

These are the main home

of a particular species
of flat-backed lizards.

The males are brilliantly colored.

The females, on the other hand,
are very different.

They are plain and drab.

The brilliance of a male's colours
is an indication

of its physical fitness
and strength.

The higher their status,
the more colorful they are.

And they're not afraid
to make their seniority quite clear.

A side-shuffle dance
showing off their colours

is usually quite enough
to settle who is the boss.

But if that doesn't work,

they fight.

Their disputes are
all about location.

Sometimes they want a vantage point
from which to show off.

At others, a good place to hide,

or to get close to the river
where there's food.

Here on these falls,
food means flies.

The river is a breeding ground
for black flies.

There are huge swarms of them.

And they are the favourite food
of the lizards.

They have acrobatic skills
needed to catch them.

While the colorful males
are busy feeding,

a different kind of male appears.

He is brown, rather like a female.

There's just a hint of blue
on his throat

that gives him away as a male.

He's fully mature,

but not yet strong enough to compete
with his flashier neighbours.

To avoid fighting, he delays
the development of his colours

and so mimics a female.

One in ten young males
behave in this this way.

But he still needs to eat,

and to do that, he's got to get down
to the river where the flies are.

That means getting past
the powerful, highly-colored males.

One thing could reveal
the deception -

he may look like a female,
but he smells like a male.

As long as he keeps his distance,
he'll be alright.

The big male hasn't noticed
that he's not a female.

Almost there.

Only one male now stands in his way.

The most dominant and aggressive
of the lot.

He's made it.

His disguise worked
and now he can feast on the flies.

He won't be able
to keep this up forever.

Ultimately, all males have to
put on their glad rags

and develop those bright colours
if they are to breed.

For now, though, he's developed
a disguise that enables him to cheat

in one of nature's most
color-dependent mating systems.

So, animals of all kinds use color
in a multitude of different ways.

New discoveries are giving us
fresh insights

into the lives of these animals,

and new cameras are allowing us
to see into a world of color

as never before.

We're only just beginning
to understand

the many different ways
in which animals use color,

particularly those colours
that we can't even see.

For us, color in the natural world
is a source of beauty and wonder,

but for animals,
it's a tool for survival.

We've seen in this series that
color is crucial for survival.

So what happens to animals
when their world changes color?

The experts we've worked with
in the field

have been helping us to find out.

In the Cairns in Scotland,
I met Jim Corn foot,

a land manager and an expert

on the natural history
of these mountains.

How long have you been here now?

Over 30 years
since I started up here,

so I've seen a lot
of different changes.

In what way?

On the Cairn plateau,

there's areas where we have
snow patches lasting all year round,

but if you look at
the last, sort of, 20 years,

there's five, six times
where the snow has completely gone,

and in over, sort of,
200, 250 years,

there's only been seven times
that that's happened.

Has that had a great effect
on the wildlife?

You know, they're out of kilter,
basically,

with what's going on
around them.

So, things like mountain hare,
ptarmigan,

they're standing out with the browns
and the heather behind them.

And they're still white?

And they're still white, yeah,
so they're not set up for that.

So if it's a very poor winter,
you know, they're suffering.

Ptarmigan, a kind of grouse,

live year round
in this exposed environment,

where there are few places to hide.

And now, as the world warms,
things are changing dangerously.

The recent decrease in snow cover
has made them only too conspicuous.

Animals like this mountain hare,
also in its winter coat,

can be seen from far away.

And that makes life very hazardous.

BIRDS CAW

These changes are affecting animals
all around the Northern Hemisphere.

In North America, the reduced
snow cover has caused snowshoe hares

to be mismatched on average
for a week a year.

During this time,

the hare is 10% more likely
to end up as someone else's dinner.

By the end of the century,

the loss of snow cover is predicted
to expose the hares

for up to eight weeks a year,

so increasing their annual mortality
by almost a quarter.

Unless they can adapt rapidly,

they could be in serious danger
of extinction.

While a warming climate
is causing problems

in northern habitats...

...it's also driving color changes
in other parts of the world.

Including some of the most
beautiful, color-rich habitats

on our planet...

...coral reefs.

Our Australian team spent months

filming on the Great Barrier Reef.

In these sunlit waters,
color is everywhere.

But this habitat is being subjected

to the most drastic color change
imaginable.

And our crew witnessed it firsthand.

The corals have suddenly turned
into white skeletons.

It's called coral bleaching

and it's now happening
only too frequently.

On the Great Barrier Reef,
such events have increased

from once in every 25 years

to three events in the last five.

Professor Jorge Weizmann

from the Coral Reef Laboratory
at the University of Southampton

has been working to discover
what is behind these changes.

The key is the relationship
between coral

and the microscopic algae
that live in their tissues.

These algal partners
are called symbionts.

It's they that give the coral
its color.

The algae, when they photosynthesis
during the daylight hours,

use sunlight to grow,

excreting sugars as a by-product,

which are then absorbed
by the corals.

This partnership was established
during the time of the dinosaurs

and has been such a success

that it has created structures
that are visible from space.

But warming seas are
disrupting this system.

So, when the seawater temperatures
rise above a critical threshold,

the photosynthetic machinery
of the algal symbionts

starts to malfunction.

SIR DAVID:
They begin to produce toxic compounds

which cause the corals to expel them
from their tissues.

So the coral loses its color.

It bleaches.

Sometimes the bleached corals die,

and then the entire ecosystem,

together with everything
it supports, is lost.

Almost half of the corals
in the Great Barrier Reef

have died this way
over the last 15 years.

But in the last decade,

there have been reports
from various parts of the world

of coral developing
startling neon colours.

We are just beginning to realise

that corals are using color
to fight back.

Org is studying how this works.

JOG: This coral has lost
its algal symbionts,

but instead of turning white,

it's producing
these bright neon green pigments.

The coral produces these pigments

to protect the remaining algae
inside of the tissue

from excess light stress,

so they act as a sort of sunscreen
for the symbiont algae.

SIR DAVID:
This coral sunscreen makes it more likely

that the bleached coral will be able
to take back its algal partners,

restoring its food supply,
its color,

and helping it to recover.

But even this extraordinary adaptation
is not enough

to protect coral against
all the changes it is now facing.

If corals have been exposed
only to mild stress,

then they can recover
from bleaching.

SIR DAVID:
But if corals are subjected

to prolonged or extreme levels
of heat stress,

they lose their ability
to create these sunscreen pigments

and are likely to die -

and unfortunately, global warming
is making this more likely.

There's a severe danger

that corals will be exposed
to episodes of stress

where they can't recover

and where they can't use
these pigments

to bounce back from bleaching.

SIR DAVID: So although color might be
helping coral reefs

to tolerate some of the change,

only action to halt global warming
will ensure their survival.

If warming continues, then they,

together with the beautiful array
of color they provide,

will disappear
from the reefs of the world.