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[sweeping orchestral music playing]

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[Attenborough]
The natural world is full of colours.

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Colours that attract attention.

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Colours that blend beautifully
with their background.

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And colours
that create extraordinary displays.

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There are few animals
more brilliantly coloured

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than these scarlet macaws.

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Animals can use colour
for all kinds of different reasons,

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

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But with new cameras,

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some developed especially for this series,

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we can reveal a world
that has long been hidden from our eyes.

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A world of colours
that only some animals can see.

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Secret communication channels
for the most private of messages.

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And colours so bold and brilliant,
they dazzle our senses.

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Whether to win a mate…

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or beat a rival,

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to warn off an enemy

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or to hide from one.

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We will reveal extraordinary stories
about Life in Colour.

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[calling]

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[mysterious orchestral music playing]

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The rocky hills of Southern India.

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The stage is set for a performance

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of one of the most spectacular dances
in the natural world.

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[peacocks calling]

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Peacocks are gathering.

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[jaunty orchestral music playing]

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This, surely,

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is one of the most glamorous
of all sights in nature.

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A hundred and fifty shimmering eyespots,

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carried on tail feathers
that are six feet long.

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So how did such glories evolve?

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It seems it's all down to the female.

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[calling]

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The brighter a male's colours

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and the greater the number
of his feathery eyespots,

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the more attractive she will find him.

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But colours and plumes like these
come at a cost.

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The immense tail makes flying difficult.

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The males are literally weighed down
by their feathers.

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Yet the colours they carry
are clearly very important to them.

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So why and how
has colour taken on such value?

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[tranquil orchestral music playing]

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To understand that,

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we have to think back
to when it all began.

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Seven hundred million years ago,

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our planet was far less colourful.

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But the first animals, it seems,

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had eyes that were unable
to distinguish colours anyway.

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Gradually, however, this changed.

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I am in Costa Rica…

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a good place to see
how valuable colour can be.

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This toucan likes fruit,

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and its ability to choose ripe fruit
from unripe depends on colour,

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because the ripe ones are black.

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And this capacity of choosing
between different colours

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was a very important stage
in the evolution of colour vision.

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[optimistic classical music playing]

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Birds,

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close relatives of dinosaurs,

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appeared before mammals.

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The first mammals, as far as we can tell,

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were mostly nocturnal.

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Colours are not easily distinguishable
at night,

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so why evolve the ability to detect them?

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So it seems
that the first mammals themselves

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were not very colourful.

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And this is still largely true today.

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Most are shades of black and white.

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Or brown.

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But there are exceptions.

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And one of the most dramatic

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lives in the forests of Gabon
in West Africa.

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[mysterious orchestral music playing]

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[bird calling]

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These monkeys are mandrills,

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a kind of baboon.

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They live in large troops.

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Most are females and youngsters,

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both of which are brown.

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But the males are different.

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They, when they're young,

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have very plain faces with naked muzzles.

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As they grow, their faces begin to change.

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Testosterone begins
to flow through their veins.

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When they're about six years old,

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they leave the troop
and start to fend for themselves.

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As they become sexually mature,

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colour appears in their faces.

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And what colour!

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[tense orchestral music playing]

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Mandrill males
are the biggest of all monkeys,

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weighing over 30 kilos.

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Enormously, frighteningly powerful.

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And their colours say so.

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[mandrills shrieking]

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[mandrill shrieking]

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It is not only his face which is coloured.

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So is his rump.

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Both are fearless declarations

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of his health and strength.

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And this male is more than happy to prove
just how strong he is

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should any male dare to challenge him.

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Not surprisingly,

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mandrill eyes
are particularly sensitive to colour.

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And it's the brightness of their colours
which signals their status.

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[tense orchestral music building]

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[mandrill shrieking]

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There are four males in this troop,

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and they're constantly flexing
their muscles

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and displaying their colours
to establish who is the strongest.

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And not all disputes
are settled peacefully.

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They emphasise their ferocity by gestures,

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such as grinding their teeth.

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If that doesn't work,

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the highest-ranking male will fight…

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[mandrill grunting aggressively]

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and the others know it.

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It's better to let colour do the talking.

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[grunting]

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Mandrills see the world much as we do

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and have three kinds
of colour-sensitive cells.

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[serene orchestral music playing]

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But another group of animals
has colour vision that's far superior

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to that of any mammal.

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Birds.

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[birds calling]

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Their ability varies from group to group,

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but you can judge how good they are

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from the colours they use
to signal to one another.

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[whispering]
Hummingbirds have excellent colour vision,

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because that enables them
to spot brightly coloured flowers,

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which contains the nectar
on which they feed.

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So this artificial feeder
is a big success.

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Brightly coloured down here

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and containing sugar solution,
artificial nectar, up there.

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But hummingbirds also use their ability
to see colour in a different way,

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to attract a mate.

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Most species live in South America,

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where there are flowers of some sort
all year round.

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[birds chirping, calling]

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A few, however, have spread northwards

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into the deserts
of the American Southwest.

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[tranquil orchestral music playing]

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In this vastness,

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it's hard to get noticed,

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especially if you're a small hummingbird
looking for a mate.

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But this male Costa's hummingbird
uses his colours to send a secret message.

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Out in the open,

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flashy colours
can attract unwanted attention,

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so he keeps them hidden most of the time.

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A slight turn of the head, however,

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provides a tantalising glimpse
of what he has to offer.

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He's spotted a female.

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She's feeding.

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Hummingbirds live fast lives
and need plenty of fuel.

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So if he is to attract her attention,
he needs something eye-catching.

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Time to reveal his colours.

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Erecting the iridescent feathers
on his neck,

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he positions himself
to catch the sunlight.

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Seen at just the right angle,
his colours are dazzling.

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Aerobatics like these
take a lot of energy,

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so his performance can give her clues
about his health and fitness.

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Every second she takes to decide
burns up his energy reserves.

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So he can only hover for so long.

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At last,

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his colours have persuaded her.

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Displaying your colours
is easy out in the open.

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[mysterious orchestral music playing]

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Birds which live in dark forests, however,

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have to work harder to get noticed.

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The rainforests of New Guinea.

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Here, the trees stand 100 feet tall

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with their crowns forming
a near-continuous canopy.

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But here and there,

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there's a small gap
through which a shaft of light

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illuminates a patch on the forest floor.

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A stage for one of the most
versatile dancers in the natural world.

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A bird of paradise.

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There are over 30 different species.

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This one, understandably,

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is called
the magnificent bird of paradise.

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A male.

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Before starting his show,

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he clears his stage.

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The bare brown earth
will make his colours stand out better.

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He takes particular care
to remove anything green.

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That colour will be
the main feature of his display,

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and he doesn't want any competition.

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Satisfied at last.

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A sapling in the centre
will serve as his dancing pole.

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His costume must be immaculate.

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Plumes like these need careful attention.

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Time to summon the audience.

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[calling]

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[calling continues]

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The first to appear are all young males.

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They won't develop their colours
until they're seven years old.

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They have come to watch and to learn.

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[calling]

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At last, a female.

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She looks much like a young male
to our eyes,

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but he can clearly tell the difference.

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[whimsical orchestral music playing]

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She will judge him by his performance
and the brightness of his feathers.

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She does that from directly above him.

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He puffs up his feathers
and swings round to show her his colours.

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For years,

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naturalists only watched this performance
from ground level.

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00:19:20,080 --> 00:19:22,880
But the female does so from above.

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00:19:27,720 --> 00:19:28,840
And from there,

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his brilliant green colours
stand out vividly

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00:19:31,920 --> 00:19:33,960
against the brown of the ground.

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00:19:38,160 --> 00:19:42,880
A pair of bare quivering quills
sprouting from his tail

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add to the excitement.

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This is one of the most complex
of all courtship dances,

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and we're still unaware of the details
that she may regard as critical.

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00:20:08,840 --> 00:20:12,200
The prize-giving, however,
is unmistakable.

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The colour vision of birds
is mostly excellent…

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00:20:30,480 --> 00:20:33,520
but that of many insects
is almost as good.

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[serene orchestral music playing]

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Butterflies.

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They, too,
have evolved an astonishing variety

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00:20:51,360 --> 00:20:53,240
of colours and patterns.

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00:21:05,920 --> 00:21:10,600
The wings are covered by tiny scales,
like tiles on a roof,

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and it's they that produce
some of the colours.

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00:21:17,920 --> 00:21:19,680
Some have pigments.

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Others reflect light
to produce a shimmering iridescence

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with colours that change
according to the angle

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00:21:28,880 --> 00:21:30,440
from which they're viewed.

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00:21:43,000 --> 00:21:45,200
But some butterflies use colours

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00:21:45,280 --> 00:21:48,280
that are invisible to our eyes.

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00:21:57,000 --> 00:22:01,160
The glorious colours
of an English meadow in bloom

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00:22:01,240 --> 00:22:04,280
is a delight to the eyes of many of us.

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00:22:05,200 --> 00:22:08,120
But their purpose is not to appeal to us.

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00:22:08,960 --> 00:22:13,960
It's to attract insects
such as butterflies and bees.

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00:22:15,800 --> 00:22:20,440
Most of these plants
depend on insects to pollinate them,

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00:22:21,560 --> 00:22:25,360
and they use their bright colours
in order to attract insects.

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00:22:26,200 --> 00:22:29,720
But to understand what an insect sees,

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we have to be able
to see it through their eyes

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and from their perspective.

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00:22:35,160 --> 00:22:39,560
And, happily, we've got a camera
that enables us to do just that.

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00:22:44,000 --> 00:22:48,680
This camera setup lets us look
at that flower in two different ways.

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00:22:49,720 --> 00:22:52,520
This camera is an ultraviolet camera

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00:22:52,600 --> 00:22:57,200
because it has a filter there
that only lets through ultraviolet light.

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00:22:57,920 --> 00:23:02,400
But, at the same time,
this filter also reflects normal light,

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00:23:02,480 --> 00:23:06,360
and that comes into this camera,
and that shows what we can see.

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So I can compare the two very easily.

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00:23:10,040 --> 00:23:11,720
That's what we can see…

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00:23:15,320 --> 00:23:17,200
and that's what the insect sees.

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00:23:17,720 --> 00:23:19,840
[enchanting orchestral music playing]

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00:23:19,920 --> 00:23:23,080
Flowers have evolved
these ultraviolet markings

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00:23:23,160 --> 00:23:26,720
for the benefit of insects
such as butterflies.

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00:23:35,960 --> 00:23:40,000
This particular one lives
in the rainforests of Eastern Australia.

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00:23:41,040 --> 00:23:43,480
It's a blue moon butterfly.

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A male.

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You might not think
that it's the most colourful

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you've ever seen,

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but with our ultraviolet camera,

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00:23:56,840 --> 00:23:59,560
his wings take on a magical look.

262
00:24:05,480 --> 00:24:07,040
The brighter his patches,

263
00:24:07,120 --> 00:24:09,680
the more attractive he is to females.

264
00:24:14,280 --> 00:24:16,880
But ultraviolet markings like these

265
00:24:16,960 --> 00:24:20,640
can also be seen
by the blue moon's main predators.

266
00:24:23,320 --> 00:24:25,960
Birds can see them just as clearly.

267
00:24:29,720 --> 00:24:33,880
So flying around with a bright signal
like that on your wings

268
00:24:33,960 --> 00:24:35,080
could be dangerous.

269
00:24:41,680 --> 00:24:45,160
For a male, however,
it's worth living dangerously.

270
00:24:45,880 --> 00:24:49,480
If he can mate with one or two females
in his short lifetime,

271
00:24:49,560 --> 00:24:52,080
his colours will have been a success.

272
00:24:59,960 --> 00:25:01,960
But he has competition.

273
00:25:03,680 --> 00:25:07,680
He will have to defend his territory
if he's to secure a mate.

274
00:25:11,160 --> 00:25:15,440
Butterfly wings are fragile,
so physical combat is to be avoided.

275
00:25:18,280 --> 00:25:22,720
Disputes, instead,
are settled with aerial displays.

276
00:25:32,000 --> 00:25:35,320
A female has been watching
from the sidelines.

277
00:25:39,920 --> 00:25:42,360
Time to show her his colours.

278
00:26:01,040 --> 00:26:04,360
In her eyes, he's simply dazzling.

279
00:26:19,960 --> 00:26:22,680
Ultraviolet colours
are part of the spectrum

280
00:26:22,760 --> 00:26:26,520
that insects can see and we cannot.

281
00:26:28,960 --> 00:26:31,040
Recent discoveries have revealed

282
00:26:31,120 --> 00:26:34,760
that some animals can also see
a characteristic of light

283
00:26:34,840 --> 00:26:36,560
that we cannot detect.

284
00:26:38,520 --> 00:26:43,640
Sunlight contains rays
that vibrate in many different planes.

285
00:26:44,760 --> 00:26:48,320
In polarised light,
they vibrate in only one.

286
00:26:50,200 --> 00:26:52,680
Light may become polarised

287
00:26:52,760 --> 00:26:56,120
when reflected off a shiny surface
such as water.

288
00:26:57,520 --> 00:27:01,920
Unlike us,
some animals can see polarised light,

289
00:27:02,440 --> 00:27:05,160
and they can exploit it in many ways.

290
00:27:10,000 --> 00:27:11,840
One creature that does so

291
00:27:11,920 --> 00:27:16,120
lives on these vast mudflats
in Northern Australia.

292
00:27:17,320 --> 00:27:19,320
[whimsical orchestral music playing]

293
00:27:21,080 --> 00:27:26,480
These eyes, on stalks,
belong to a male fiddler crab.

294
00:27:29,000 --> 00:27:32,120
And they can see in a way that we cannot.

295
00:27:40,120 --> 00:27:41,800
As the tide goes out,

296
00:27:41,880 --> 00:27:44,560
the crabs emerge from their burrows.

297
00:27:52,000 --> 00:27:56,840
His giant claw is too large
to be used in feeding.

298
00:27:59,520 --> 00:28:03,680
Instead, he uses it
to attract the attention of females

299
00:28:03,760 --> 00:28:06,040
by waving it with vigour.

300
00:28:08,960 --> 00:28:13,040
The crabs can see objects
that are close to them reasonably well…

301
00:28:15,960 --> 00:28:19,440
but their long-distance eyesight
is not so good.

302
00:28:24,400 --> 00:28:27,560
Polarised light
can help solve the problem.

303
00:28:32,280 --> 00:28:34,600
Viewed with a new specialist camera,

304
00:28:34,680 --> 00:28:37,960
the mudflats,
which reflect polarised light,

305
00:28:38,040 --> 00:28:39,120
are bright…

306
00:28:41,920 --> 00:28:46,800
while the unpolarised crabs
appear darker against their background.

307
00:28:48,400 --> 00:28:53,040
This striking contrast
also makes the large claw more obvious.

308
00:28:55,720 --> 00:29:00,280
The big claw is also used by the male
to defend his burrow.

309
00:29:05,000 --> 00:29:07,000
Not everyone heeds the warning.

310
00:29:07,520 --> 00:29:10,280
[playfully tense orchestral music playing]

311
00:29:21,840 --> 00:29:22,920
Battle over.

312
00:29:26,040 --> 00:29:29,240
But there are
more dangerous enemies to face.

313
00:29:29,320 --> 00:29:30,840
Aerial predators.

314
00:29:31,800 --> 00:29:34,360
The quicker they can spot them
the better.

315
00:29:34,440 --> 00:29:35,520
[birds screeching]

316
00:29:35,600 --> 00:29:39,680
And, once again,
polarised light helps them to do so.

317
00:29:50,720 --> 00:29:52,960
[whimsical orchestral music playing]

318
00:29:53,040 --> 00:29:54,320
With the coast clear,

319
00:29:54,960 --> 00:29:57,640
a male reemerges from his burrow.

320
00:30:01,120 --> 00:30:03,080
At last, a female.

321
00:30:09,880 --> 00:30:11,600
With the tide on the turn,

322
00:30:11,680 --> 00:30:14,240
he must work fast to win her over.

323
00:30:21,000 --> 00:30:21,920
And close up,

324
00:30:22,000 --> 00:30:24,120
his colours come into play.

325
00:30:25,360 --> 00:30:29,480
The brightness of his blue back
could be the deciding factor.

326
00:30:38,840 --> 00:30:40,520
She may not look willing,

327
00:30:40,600 --> 00:30:44,680
but the pushing and shoving
are all part of the mating ritual.

328
00:30:49,080 --> 00:30:50,640
One last shove

329
00:30:51,400 --> 00:30:52,520
and she's in.

330
00:30:55,720 --> 00:30:56,840
Just in time.

331
00:31:11,120 --> 00:31:15,920
On land, colour is used
in a multitude of different ways.

332
00:31:16,520 --> 00:31:18,440
The same is true in the sea,

333
00:31:19,040 --> 00:31:22,480
but there,
colour works in a very different way.

334
00:31:24,040 --> 00:31:26,840
[enchanting orchestral music playing]

335
00:31:32,200 --> 00:31:35,200
This is Australia's Great Barrier Reef,

336
00:31:35,720 --> 00:31:39,360
and its shallow waters
are full of vivid colour.

337
00:31:45,520 --> 00:31:48,880
The inhabitants of the reef
exploit it to the full

338
00:31:49,400 --> 00:31:52,320
with unparalleled and dazzling effect.

339
00:32:08,720 --> 00:32:12,600
The orange-red stripes
of the harlequin tuskfish

340
00:32:12,680 --> 00:32:14,400
make it very conspicuous.

341
00:32:18,160 --> 00:32:20,440
But as light filters down
through the water,

342
00:32:20,520 --> 00:32:23,840
more and more of its wavelengths
are absorbed,

343
00:32:24,880 --> 00:32:27,680
and red is the first to disappear.

344
00:32:29,920 --> 00:32:33,120
So as the harlequin swims downwards,

345
00:32:33,200 --> 00:32:37,040
his brilliantly coloured red body
looks duller and duller.

346
00:32:48,440 --> 00:32:52,520
Different colours are absorbed
at different rates in the sea,

347
00:32:53,280 --> 00:32:56,560
but some can still be seen
at greater depths.

348
00:33:00,120 --> 00:33:02,400
Yellow and blue travel farthest,

349
00:33:02,480 --> 00:33:07,240
so it's these that many fish down here use
to signal their identity.

350
00:33:13,320 --> 00:33:16,240
Most fish near the surface
have good colour vision,

351
00:33:16,880 --> 00:33:21,440
but some of the smaller species
can also see ultraviolet colours.

352
00:33:25,200 --> 00:33:29,160
To us, these yellow damselfish
all look very similar.

353
00:33:34,640 --> 00:33:36,960
But using our ultraviolet camera,

354
00:33:37,480 --> 00:33:40,680
we can see that many fish
have different patterns

355
00:33:40,760 --> 00:33:44,120
that are normally invisible to our eyes.

356
00:33:48,320 --> 00:33:49,320
And suddenly,

357
00:33:49,400 --> 00:33:51,960
it becomes clear
that these two individuals

358
00:33:52,040 --> 00:33:54,720
are, in fact, different species.

359
00:33:58,640 --> 00:34:03,720
This lemon damselfish
has distinctive spots on its gill covers.

360
00:34:06,400 --> 00:34:09,400
And this, an Ambon damsel,

361
00:34:09,480 --> 00:34:14,360
has bright reflecting ultraviolet patches
all across the body.

362
00:34:17,120 --> 00:34:19,400
It's a code invisible to us

363
00:34:19,480 --> 00:34:22,360
that allows these fish
to recognise each other…

364
00:34:24,680 --> 00:34:27,760
without attracting the attention
of large predators,

365
00:34:27,840 --> 00:34:31,000
which can't see in the ultraviolet range.

366
00:34:38,840 --> 00:34:40,440
And it's on the seabed

367
00:34:40,520 --> 00:34:44,520
that you can find one of the most
colourful sea creatures of all.

368
00:34:50,840 --> 00:34:53,400
The peacock mantis shrimp.

369
00:34:54,080 --> 00:34:56,440
[jaunty orchestral music playing]

370
00:34:59,400 --> 00:35:02,080
This strange-looking creature's ancestry

371
00:35:02,160 --> 00:35:05,520
can be traced back 400 million years,

372
00:35:07,480 --> 00:35:10,440
and it has one of the most
versatile kinds of eyes

373
00:35:10,520 --> 00:35:12,680
in the whole of the animal kingdom.

374
00:35:17,920 --> 00:35:22,920
It can rotate its two huge eyes
independently of each other

375
00:35:23,000 --> 00:35:24,920
and in almost any direction.

376
00:35:27,280 --> 00:35:30,040
We have three kinds of colour receptors,

377
00:35:30,120 --> 00:35:32,280
but the mantis shrimp has 12,

378
00:35:32,360 --> 00:35:35,080
each with a direct link to the brain,

379
00:35:35,160 --> 00:35:39,200
so it can perceive colour faster
than any other animal.

380
00:35:41,080 --> 00:35:46,440
And it can also detect the difference
between polarised and unpolarised light.

381
00:35:50,520 --> 00:35:52,320
But unlike fiddler crabs,

382
00:35:52,400 --> 00:35:55,920
part of its body,
like these paddle-shaped scales,

383
00:35:56,000 --> 00:35:58,440
reflect polarised light

384
00:35:59,160 --> 00:36:02,680
and may be used
to signal to potential mates.

385
00:36:09,360 --> 00:36:13,760
The tail is also highly polarised
and used to plug its burrow

386
00:36:13,840 --> 00:36:17,360
and send a message
to warn off potential rivals.

387
00:36:23,160 --> 00:36:26,600
And by combining all its visual abilities,

388
00:36:26,680 --> 00:36:31,760
the mantis shrimp has become
one of the most skilful of all predators.

389
00:36:36,640 --> 00:36:40,840
[tense orchestral music playing]

390
00:36:43,760 --> 00:36:48,480
It also packs a powerful punch
from club-like mouthparts…

391
00:36:52,160 --> 00:36:54,640
which it uses with great accuracy.

392
00:36:59,840 --> 00:37:04,040
These clubs deliver
the fastest punch in the animal kingdom,

393
00:37:05,200 --> 00:37:08,400
and it's guided
by its extraordinary vision.

394
00:37:18,760 --> 00:37:21,640
Whether underwater or on land,

395
00:37:21,720 --> 00:37:24,440
colour can be extremely useful.

396
00:37:28,880 --> 00:37:31,520
And the colours an animal develops

397
00:37:31,600 --> 00:37:36,720
can sometimes be influenced
by where it lives and what it eats.

398
00:37:36,800 --> 00:37:38,800
[sweeping orchestral music playing]

399
00:37:45,520 --> 00:37:48,560
The Atacama Desert in South America.

400
00:37:52,800 --> 00:37:55,160
[bird calling]

401
00:38:00,040 --> 00:38:03,520
There are six different species
of flamingos in the world,

402
00:38:04,280 --> 00:38:09,040
and they all prefer to breed
in those most hostile of environments,

403
00:38:09,600 --> 00:38:12,080
salt flats and soda lakes.

404
00:38:17,280 --> 00:38:21,120
We think of flamingos
as being characteristically pink,

405
00:38:21,200 --> 00:38:23,600
but their feathers,
when they first appear,

406
00:38:23,680 --> 00:38:25,200
are, in fact, white.

407
00:38:29,600 --> 00:38:32,320
Their colour comes from their food.

408
00:38:35,640 --> 00:38:40,160
The salty waters in which they feed
are rich in algae and shrimps,

409
00:38:40,240 --> 00:38:44,600
both of which contain red pigments
called carotenoids.

410
00:38:47,320 --> 00:38:48,440
These, over time,

411
00:38:48,520 --> 00:38:52,120
accumulate in their feathers
and give them their bright colour.

412
00:38:56,400 --> 00:38:59,160
[tranquil orchestral music playing]

413
00:39:08,960 --> 00:39:11,160
These youngsters were born last year.

414
00:39:12,160 --> 00:39:15,160
They still have
their first greyish-white plumage.

415
00:39:21,720 --> 00:39:24,800
It takes time
before the pigments become visible.

416
00:39:30,440 --> 00:39:32,720
Five years will pass

417
00:39:32,800 --> 00:39:35,880
before they become
as pink as their parents.

418
00:39:44,440 --> 00:39:47,280
But it's not only the juveniles
which are white.

419
00:39:53,200 --> 00:39:56,720
This adult female
raised a chick last year,

420
00:39:56,800 --> 00:40:00,840
and the effort of doing so
has drained her of colour.

421
00:40:03,480 --> 00:40:06,120
She put all her surplus food and energy

422
00:40:06,200 --> 00:40:09,960
into producing an egg
and then feeding her chick.

423
00:40:11,840 --> 00:40:15,400
So she will need time
to build up the body reserves needed

424
00:40:15,480 --> 00:40:18,680
to regrow pink feathers and breed.

425
00:40:26,760 --> 00:40:29,600
For those that are old enough
and physically fit,

426
00:40:29,680 --> 00:40:31,800
it's time to find a mate.

427
00:40:35,680 --> 00:40:39,280
Only the pink birds take part
in these courtship dances.

428
00:40:43,440 --> 00:40:47,400
Their colour is an indication
that they're fit and strong.

429
00:40:48,840 --> 00:40:50,840
[sweeping orchestral music playing]

430
00:41:07,240 --> 00:41:08,960
As they march through the water,

431
00:41:09,040 --> 00:41:12,200
each bird tries
to stand out from the crowd,

432
00:41:13,160 --> 00:41:17,120
and the brightest
will be the first to secure a partner.

433
00:41:24,200 --> 00:41:28,680
The white female can play no part
in this year's display.

434
00:41:35,400 --> 00:41:40,160
She will need to eat as much as she can
if she is to restore her colour.

435
00:41:43,400 --> 00:41:48,200
Maybe next year she will be able
to rejoin the dance.

436
00:41:59,760 --> 00:42:04,800
Flamingos depend on their pink colour
to attract a partner and breed.

437
00:42:07,840 --> 00:42:11,920
But there is one tiny animal
in the Central American rainforests

438
00:42:12,000 --> 00:42:15,240
that uses colour not only to attract,

439
00:42:15,320 --> 00:42:16,600
but to repel.

440
00:42:26,960 --> 00:42:30,480
This little frog uses colour as a warning.

441
00:42:31,320 --> 00:42:35,800
Its skin is full of glands
which produce a deadly poison.

442
00:42:36,400 --> 00:42:38,680
So its colour is a very clear message.

443
00:42:39,240 --> 00:42:41,560
"Eat me and you'll regret it."

444
00:42:45,320 --> 00:42:47,960
You need a vivid message like this

445
00:42:48,040 --> 00:42:52,800
if you are a small,
soft-skinned, bite-sized mouthful

446
00:42:52,880 --> 00:42:55,520
living in a dark, dense forest.

447
00:42:55,600 --> 00:42:57,600
[menacing orchestral music playing]

448
00:43:08,160 --> 00:43:11,440
The rainforest can be a scary place.

449
00:43:16,040 --> 00:43:18,560
There are hungry animals everywhere.

450
00:43:33,560 --> 00:43:37,240
For many, it's best to keep a low profile.

451
00:43:41,840 --> 00:43:44,200
But this little frog doesn't.

452
00:43:45,760 --> 00:43:48,800
It's a strawberry poison dart frog,

453
00:43:48,880 --> 00:43:51,640
and it's not much bigger
than your fingernail.

454
00:43:52,520 --> 00:43:55,520
And yet
he is one of the deadliest creatures here.

455
00:43:58,600 --> 00:44:01,480
His bright skin secretes a toxin.

456
00:44:03,400 --> 00:44:05,320
In the mouth of a predator,

457
00:44:05,400 --> 00:44:10,120
it can cause respiratory failure,
convulsions, and death.

458
00:44:13,520 --> 00:44:18,440
Predators recognise his colour
as a sign of danger and avoid him.

459
00:44:24,920 --> 00:44:29,200
Such frogs also live
on a group of islands just off Panama

460
00:44:29,280 --> 00:44:31,560
called Bocas del Toro.

461
00:44:33,720 --> 00:44:35,320
Living in isolation,

462
00:44:35,400 --> 00:44:39,560
frogs on each island
evolved their own distinctive colours.

463
00:44:42,440 --> 00:44:45,120
There is a different one on each island.

464
00:44:48,800 --> 00:44:51,440
And yet they're all the same species.

465
00:44:57,440 --> 00:45:00,680
They're different
because the diet on some islands

466
00:45:00,760 --> 00:45:03,840
makes some more poisonous than others.

467
00:45:03,920 --> 00:45:06,080
And the more poison a frog has,

468
00:45:06,160 --> 00:45:08,440
the more brightly coloured it is.

469
00:45:17,280 --> 00:45:18,920
On Solarte Island,

470
00:45:19,000 --> 00:45:21,720
a red male is busy calling.

471
00:45:21,800 --> 00:45:23,760
[calling rapidly]

472
00:45:31,080 --> 00:45:35,280
This is his patch,
and he's looking for a female.

473
00:45:38,520 --> 00:45:39,880
He should be popular.

474
00:45:39,960 --> 00:45:42,800
Females prefer bright, shiny skin,

475
00:45:42,880 --> 00:45:44,760
which is a sign of fitness.

476
00:45:49,120 --> 00:45:53,640
His colour is also an indication
to other males of his strength.

477
00:45:54,520 --> 00:45:56,560
[tense orchestral music playing]

478
00:46:02,720 --> 00:46:04,120
He spots an intruder.

479
00:46:05,280 --> 00:46:09,080
He's about the same size,
but he's a paler colour.

480
00:46:18,600 --> 00:46:21,800
And he doesn't challenge
the brighter frog.

481
00:46:28,080 --> 00:46:30,760
But this one is a different matter.

482
00:46:32,120 --> 00:46:33,640
[Western-style guitar playing]

483
00:46:33,720 --> 00:46:35,760
He is a contender.

484
00:46:46,760 --> 00:46:49,680
Nothing for it but to fight it out.

485
00:46:50,720 --> 00:46:53,320
[jaunty orchestral music playing]

486
00:47:28,200 --> 00:47:29,640
[frog calling]

487
00:47:31,280 --> 00:47:32,160
That did it.

488
00:47:33,400 --> 00:47:35,200
He won't be back for a while.

489
00:47:39,480 --> 00:47:41,480
[tranquil orchestral music playing]

490
00:47:43,080 --> 00:47:44,240
And the reward,

491
00:47:45,040 --> 00:47:46,160
a new mate.

492
00:47:52,720 --> 00:47:54,520
For these tiny frogs,

493
00:47:54,600 --> 00:47:58,200
colour is central
to all aspects of their lives.

494
00:47:58,880 --> 00:47:59,960
For protection,

495
00:48:00,040 --> 00:48:03,760
to dominate rivals, and to find a partner.

496
00:48:04,800 --> 00:48:08,120
For them, life is colour.

497
00:48:10,400 --> 00:48:15,200
In the next episode,
the story of Life in Colour continues,

498
00:48:15,280 --> 00:48:17,200
where the stakes are even higher,

499
00:48:17,720 --> 00:48:20,480
and colour is the key to survival.

500
00:48:21,880 --> 00:48:26,440
We discover how animals use colour
to hide from predators

501
00:48:26,960 --> 00:48:28,760
and from their prey.

502
00:48:28,840 --> 00:48:30,280
[monkeys calling]

503
00:48:31,680 --> 00:48:32,840
[snorts]

504
00:48:32,920 --> 00:48:34,880
[sweeping orchestral music playing]