Attenborough's Paradise Birds (2015) - full transcript

Birds of paradise are one of David Attenborough's lifelong passions. He was the first to film many of their beautiful and often bizarre displays, and over his lifetime he has tracked them all over the jungles of New Guinea. In this very personal film, he uncovers the remarkable story of how these 'birds from paradise' have captivated explorers, naturalists, artists, film-makers and even royalty. He explores the myths surrounding their discovery 500 years ago, the latest extraordinary behaviour captured on camera and reveals the scientific truth behind their beauty: the evolution of their spectacular appearance has in fact been driven by sex.

SQUAWKING

For 500 years, these birds have been

surrounded by myth and glamour.

And I've got to confess
that I've been fascinated by them

for most of my life.

This is just one member of
a hugely varied family

that, to my mind,
includes the most spectacular

and beautiful birds on Earth.

The birds of paradise.

And what's more,

they throw light on some of
the great mysteries of evolution.



Why have the birds of paradise
become the most diverse, bizarre

and beautiful of all bird families?

Why have they developed
the most extravagant plumes

and adornments of any group
of living things on Earth,

so that sometimes, they almost cease
to look like birds at all?

And why is it
that this extraordinary family

is largely restricted

to one jungle-covered island
in the Pacific?

TRILLING

Explorers and scientists

have been puzzling over these
questions for 500 years.

Even today, by using
the latest filming techniques,

we are making new discoveries
about their behaviour.

This surely is one of
the most spectacular sights



anyone could see
in the natural world.

The mystery of the birds of paradise

began back in the 16th century.

In 1522, a ship returning to Europe

from exploring the mysterious
islands of the Far East

brought with it,
amongst other marvels,

three extraordinary skins.

They were very like this one.

You can see it's a bird -
there's its beak, and its head.

And here are these long,
feathery plumes.

But it has no wings...

and no feet.

The explorers had been told that

that was because these birds
lived in paradise.

The ship concerned was one of five

that had set out in 1519

to sail around the world
for the very first time,

under the command of the Portuguese
explorer Ferdinand Magellan.

They endured catastrophic
tropical storms and shipwrecks.

Magellan himself was killed
in a tribal war in the Philippines.

But after three gruelling years,

the Victoria, the sole surviving
ship, arrived back in Spain.

It was loaded with wonders
and treasures,

including those first specimens
of birds of paradise.

Magellan had been presented with
these skins by a king

in the Spice Islands - the Moluccas,
as we call them today -

in eastern Indonesia.

When Magellan's men asked why
they had no wings or no feet,

the people had a problem,

because they themselves
had never seen the birds alive.

They had been traded to the islands

from islands
even farther to the east.

So they made up an answer.

They said, "Well, it's because
the birds float high in the sky,

"among the clouds, feeding on dew,

"and human beings only see them when
they die and fall to the earth."

So the first descriptions of these
"birds of the gods"

were far from first-hand.

Yet they were accepted as fact
by Europeans.

This was one of the very first
paintings of a bird of paradise,

and it appears in the margin
of a book of prayers

written in 1540,

to show the devout
the sort of creatures

they might expect to see
when they got to paradise.

But it wasn't only the pious who
were interested in the discovery.

So were naturalists.

But their understanding of the birds
was similarly clouded by mythology.

This is the first volume in a great
encyclopaedia of natural history

published in 1599 by an Italian
called Aldrovandus.

And it's full of remarkably
accurate pictures and descriptions.

There's a toucan, for example.

And here is a hornbill.

But turn another couple of pages...

..and a bird of paradise,
without legs,

floating in the skies. No wings.

And here it is
drinking dew from the clouds.

Aldrovandus was so respected
that this view of the habits

of birds of paradise persisted
well into the 17th century.

It's hardly surprising that these
pictures are wildly inaccurate,

bearing in mind that they were
drawn from those flattened skins.

After all, no-one in Europe had ever
seen wings or legs

attached to these
astonishing plumes.

So it was not unreasonable
for Europeans,

who still believed in dragons
and mermaids,

to accept that these birds
lived in paradise.

But still no-one knew
where the skins actually came from.

In fact, the birds
come from New Guinea.

It's 1,000 miles long
and lies just north of Australia.

And there, of course, the people
knew perfectly well

the truth about the birds.

They hunted them for the sake
of their plumes,

which they used as currency and in
many of their important ceremonials.

My first opportunity
to see these wonderful birds

came when I went to New Guinea
back in 1957.

We saw a wide, fertile valley
ringed with mountains.

This was our destination -
the valley of the Wahgi River.

Within a few minutes of landing,
I saw coming towards me

through the tall grass
a party of tribesmen

wearing magnificent
feather headdresses.

We filmed a celebration
called a Sing-sing,

during which tribal people,

wearing spectacular headdresses
of birds-of-paradise plumes,

gather together to dance and chant.

And I took these photographs.

They displayed them
during their dances,

showing how wealthy
each of the men were

by having these
enormous headdresses.

That's Princess Stephanie's
black tail feathers.

These are King of Saxony's feathers
from the top of the head.

These are the red plumes
of Count Raggi's bird of paradise,

and these the yellow ones
of the Lesser.

When they came to have marriages,

a party going to collect a bride
would have to take a gift

to the bride's parents
of birds-of-paradise plumes.

And they arrange them
on these great banners.

There's a front view of that
with nearly two dozen sets

of bird-of-paradise plumes
all around the side of the banner.

And down the middle there,
gold-lipped pearl shells.

For thousands of years,
the plumes have been traded

from this part of New Guinea
right across Indonesia,

up into South-East Asia and beyond.

In Europe 400 years ago,
many aristocratic families

possessed cabinets of curiosities

in which they displayed their
collections of natural wonders,

and specimens of birds of paradise
were amongst the most precious.

Their splendour even caught the eye
of British royalty.

The young Scottish prince who was
going to become Charles I of England

had his portrait painted with his
furry hat on the table beside him,

and in it, his most
treasured possession -

the plumes of birds of paradise.

Naturalists, seeking to
curry favour with the aristocracy

and get financial backing
for their expeditions,

promised to name any new species
they discovered after their patrons,

and indeed they did so.

This is Queen Carola's
bird of paradise,

with plumes on the top of his head.

This one was named
after an Italian count,

Count Raggi's bird of paradise.

This one was named after
Queen Victoria.

And this one is Prince Rudolf's
bird of paradise,

though it's more often known these
days as the blue bird of paradise.

And here is Princess Stephanie's
bird of paradise,

with a great, long, glossy
black plume.

Not all were named after royalty.

Napoleon Bonaparte's nephew,
fired with republican zeal,

named this one
Diphyllodes Respublica,

the Republican
or People's bird of paradise.

But the popular version
of the name didn't catch on,

and these days
we call it Wilson's Bird.

Unlike the showy males,

the female birds-of-paradise
are drab and brown in colour.

All look very similar, so you can
well believe that they are related.

It's just the males
with their extravagant decorations

that make the individual species
look so different.

But even as late
as the 19th century, no European

had seen anything of these birds
except their dried skins.

And people wondered what
the living birds must look like.

Errol Fuller,
a collector who owns specimens

of 37 of the 39 known species
of birds of paradise,

also paints them, and understands
the difficulties involved.

The early painters of birds couldn't
go and see these things in the wild,

and they couldn't see them
in captivity,

so they were presented
with something like this.

A dried, flattened skin that had
been brought back from New Guinea,

and this was all they had to go on
to make their painting.

This is a Black Sicklebill
bird of paradise.

And the problem they had
were things like this.

What on earth are these?

They look at first sight like wings.
But they're not wings.

The wings are down here.
They're just ornamental plumes,

and there are more
ornamental plumes down here.

So, what did the bird
do with these in life?

This is a mid-19th-century
artist's answer,

and it's wildly inaccurate.

The Sicklebill
actually displays like this.

It takes him a little time to work
up to his full display posture.

There!

He lifts up those feathery tufts
on his shoulders,

and holds them around his head so
that he hardly looks like a bird.

And he repeats the performance
on the same display post

up to five times every morning.

It wasn't until 300 years after
Europeans saw the first skins

that anyone actually saw a bird
of paradise displaying in the wild.

And the person who did so
was the British explorer

Alfred Russel Wallace
who, along with Darwin,

first proposed the theory of
evolution by natural selection.

Alfred Russel Wallace was
a great naturalist and scientist,

but he was not a wealthy man.

He earned his living by going to
the tropics and collecting insects

and birds, and sending them back
for sale to wealthy collectors

and to museums.

And he was obsessed
with birds of paradise.

In 1854, he set off for New Guinea.

He became the first European ever
to see birds of paradise display.

Here is his description
of that sight.

"On one of these trees, a dozen
or 20 full-plumaged male birds

"assemble together,
raise up their wings,

"stretch out their necks
and elevate their exquisite plumes,

"keeping them
in a continual vibration."

"At the time of excitement,

"the wings are raised vertically
over the back,

"the head is bent down
and stretched out,

"and the long plumes
are raised up and expanded

"till they form
two magnificent golden fans."

Wallace's description
amazed the world, and his book,

Travels in the Malay Archipelago,
went on to become

one of the bestselling travel books
of the 19th century.

I myself read it
when I was about nine or ten,

and the frontispiece to
the second volume fascinated me.

Here are the birds in display.

I yearned to go off
and see such a sight for myself.

It was on that first trip
to New Guinea in 1957,

for a television series called
Zoo Quest, that I got my chance.

During the first month,

we saw plenty of plumes of
birds of paradise on headdresses,

but none on the living birds.

At just one Sing-sing,

I estimated that there were
20,000 bird skins on display.

It seemed to me unlikely
that we were going to find

many birds of paradise alive
around here.

So we decided to travel
somewhere further afield,

where there were fewer people,
in order to find the living birds.

We went to the north to a valley
that was then quite unexplored,

an "uncontrolled territory",
as they called it at the time.

The people were really still
living in the Stone Age,

making stone axes like this.

We had to cross rivers with
locally made suspension bridges,

like this one.

Or even had to wade our way across,

and we had 100 porters
carrying everything we needed -

food, gifts, cakes of salt,
that sort of thing.

Eventually, we did find the birds.

The valley was throbbing with calls
of Count Raggi's Paradise Birds.

As far as we knew, no-one had ever
filmed the courtship dance

of these birds of paradise
in the wild.

And this was to be our lucky day.

We could see
his gorgeous red plumes

hanging from beneath his wings.

The plumes which make him
so coveted and so desirable a prize

for all the people hereabouts.

And then suddenly,
in a frenzy of excitement,

he threw his ruby plumes above his
head, shrieking with excitement.

Our film, even if it was in
black and white and rather fuzzy,

was the first record of a wild
bird of paradise in display,

and showed exactly
how he erected his plumes.

And this skin, which I found in
a Paris flea market some years ago,

is of the bird that we filmed
in black and white,

and here you can see how wonderfully
rich its plumage was.

This a trade skin, just as
the people prepare it in New Guinea,

without any legs
and without any wings.

Both have been removed to emphasise
the glory of these plumes.

After ten minutes,

he executed a final flutter
and flew to another branch.

But this was only
a single bird in display.

It was another 40 years
before I saw the group display

of the larger
and more impressive species,

the greater bird of paradise,
that Wallace had described.

The birds are in another
emergent tree just like this one,

and I've got an absolutely
clear view of them.

This, at last,
is Wallace's picture come to life.

Wallace described the display very
accurately, as you would expect.

But he didn't understand why
the birds were behaving like this,

in a group.

So even 300 years after
the discovery of these birds,

the purpose of their displays
still wasn't properly understood.

And it wasn't just
the greater bird of paradise

that perplexed naturalists.

The second species of bird
of paradise to arrive in Europe

at the end of the 16th century

appeared to be an even more
bizarre-looking creature.

It still had a pair of golden plumes

sprouting from its flanks to justify
it being called a bird of paradise.

It seems to have been painted
soon after its arrival,

as the gold colour fades with time,

and, like the first ones,
it had no wings or legs,

but it did have some extra,
rather mysterious adornments.

This is it.

It's called the
twelve-wired bird of paradise.

That's because it has thin, naked
quills sprouting from the tail,

six on one side, six on the other.

What were such things used for?

Some people suggested
that it wasn't natural

that they were curled up
in this way,

that it happened because of the way
the bird was packed.

Others suggested
that maybe it roosted

by hanging from them upside down.

Nobody had any idea.

In the years that followed, more
specimens of this bird appeared,

and other artists made a somewhat
better job of depicting it.

But the function of those
strange 12 wires remained a mystery.

It was only on my second trip
to New Guinea in 1997,

when we filmed the bizarre
courtship of this bird

for the very first time,
that we found the answer.

Courtship seems to be
some kind of game,

a variation of "I'm the king
of the castle", perhaps,

only with a very special prize.

He deliberately brushed her face
with his rear quills.

He's doing it again.

It seems that she prefers to be
seduced, not by visual thrills,

but by tactile ones.

It may be an odd technique,
but it works.

So it took 400 years
from the arrival of the first skin

of the twelve-wired bird to
actually record its courtship ritual

and finally solve the mystery
of the peculiar adornments.

But there's another species

whose display is perhaps the hardest
of all to interpret from its skin.

It doesn't so much
flaunt its feathers

as use them to
entirely transform itself.

This is the
superb bird of paradise,

and it has this wonderful shield
on its breast.

This blue colour isn't pigment.

It's reflected light, like that
that comes from a thin film of oil.

So it changes
according to how you view it.

But that's not its only decoration.

On its back it has a kind of cape.

These aren't wings,
they are just feathers.

How would the bird
have displayed that?

That was the problem facing
19th-century bird illustrators.

Artists did their best to work out

how the birds
showed off their ornaments.

This version shows the superb bird's
colours more or less correctly.

But otherwise,
it's nowhere near the truth.

It wasn't until
the late 20th century

that ornithologists
managed to work out

just how the superb bird uses
its feathers to transform itself.

These drawings by
the Australian artist Bill Cooper

show just how it does it.

It uses these long black feathers,
which form a cape on its back,

and brings them forward
to form a funnel.

Then the green...
Iridescent green breast shield

forms the base of the funnel.

And in the far depths, there appear
to be two eyes staring at you.

In fact,
they're not even eyes at all.

They're white spots on its head.

I think if in the 19th century
any artist had suggested that

that's what the bird did, he
really would have been ridiculed.

But no drawing
can completely capture

the extraordinary way the superb
bird transforms itself in display.

You just have to see
the living bird.

CLICKING

The rhythmic clicks are made
by flicking the wing feathers.

In 1996, I was able to watch
Bill Cooper at work

as he painted
another bird of paradise,

a Victoria Riflebird.

This is one of the few
birds of paradise

that is found outside New Guinea
or its offshore islands.

It lives in Australia,
in northern Queensland,

where Bill Cooper also has his home,
in an unspoilt patch of rainforest.

Come on, boy. Come on, gorgeous.

Oh, look at that colour!

Here he comes. Come on.

Oh, you are lovely.

As a young man,
Bill Cooper travelled

through some of the wildest parts
of New Guinea,

watching and painting the birds.

It was Count Raggi's that he
encountered first, as I had done.

It turned and faced the female,

and then the male
started shuffling towards her,

and he puffed out
his chest feathers -

I'd wondered what they were for,

but he fluffed them out
and formed a great pompom

through which his beak
was protruding.

It was a great display.

Bill Cooper, to my mind anyway,

is the greatest of all
bird-of-paradise illustrators.

And this one of the blue bird in
display is particularly successful.

He's caught this wonderful
intensity of blue

as the bird hangs upside down.

But what even Bill Cooper can't do

is to show that the male blue bird,
as he hangs like this,

actually throbs this pattern here,
making a noise at the same time

that sounds like some electronic
equipment that's gone wrong.

Images of birds of paradise
have become increasingly accurate

since those first attempts.

The plumed birds, in particular,
that dance high in the trees,

became better known scientifically

as explorers and naturalists
travelled more widely

through New Guinea's dense forests.

However, a few species
display not up in the branches,

but on the ground.

They are more difficult to observe.

But we did manage to film one
in display for the very first time

on my trip in 1997.

I have come to the island
of Batanta.

It has its own species of
bird of paradise that evolved here

and lives nowhere else.

One way of trying
to get a look at it

is to put some leaves on this arena,

because this bird
is meticulously tidy.

There he is!

Wilson's bird of paradise.

He's got his own fashion gimmick -
the bald look.

There goes the first of the leaves
that I dropped.

He is really quite small.

Only the size of a starling.

That looks like a female.

He's clearly not much of a dancer,

but with a costume like that,
who would need to be?

What an amazing bird!

I've seen lots of coloured
illustrations of them,

I have seen mounted specimens
in museums,

but nothing has prepared me for the
splendour of this wonderful thing.

Although Wilson's bird
is very spectacular,

there are other
ground-living species

with much more complex dances.

In 1876, an Italian explorer,
Luigi D'Albertis,

spent many months
charting the territory

of the then virtually unknown
interior of New Guinea.

During one of his excursions
through the forest,

his local guide pointed to a bird
sitting on a perch in a clearing.

D'Albertis's first reaction
was to shoot and skin the bird,

as he had done with every other
specimen that he had collected.

And he was just about
to pull the trigger

when the local man put his hand
on his arm and said, "Wait."

Then D'Albertis
became the first European ever

to see the display
of the parotia bird of paradise.

This is how he describes it
in his book.

"The bird spread and contracted
the long feathers on his sides

"in a way that made him appear
now larger,

"and again smaller
than his real size."

"And jumping first to one side,
and then on the other,

"he placed himself proudly
in an attitude of combat,

"as though he imagined himself
fighting with an invisible foe."

"All this time he was uttering
a curious note

"as though calling on someone
to admire his beauty,

"or perhaps challenging an enemy.

"The deep silence of the forest was
stirred by the echoes of his voice."

And then he pressed the trigger
and shot it.

GUNSHOT

"When the smoke cleared away,

"a black object
lying in the middle of the glade

"showed me that
I had not missed my mark."

"Full of joy, I ran
to possess myself of my prey.

"But, as I drew near,
my courage failed me.

"I could not stretch forth
my hand.

"And, full of remorse
I said to myself,

"'Man is indeed cruel.'

"The poor creature
was full of happiness.

"One flash from a gun
and all his joy is past."

Now, film-makers like Paul Stewart

hunt the birds not with guns,
but cameras.

Using the latest ultra-sensitive
filming equipment,

he captured the parotia's behaviour
in meticulous detail.

The key to filming them

is for them to have no idea
that you're there.

And the best way to achieve that

is to build a hide
with the help of the local people.

You go in before first light,
you leave after dusk,

and in between you are as silent
as you humanly can be.

In 2005, he spent five weeks
filming Lawes's parotia in action.

Eventually, he saw the male start
to clear his display area or court.

And then he took
a piece of damp leaf

and was shining the branch that
the female would first come into

to judge his display.

It was as if the male was directing
her to a specific vantage point.

Once he had polished the branch
to his satisfaction,

he began his display.

He had a little bow tie almost
of iridescent feathers,

but rather like a comedy bow tie,
this thing would flick up and down

while he was displaying.

Now, we thought, "That's making
a nice flash at ground level."

We should have suspected
that there was more to it.

In fact, he was looking at
and filming the bird

from the wrong angle.

It took another film crew
to reveal why.

An American team
decided to try and film

every single one of the 39
known species of birds of paradise.

Edwin Scholes and Tim Laman from the
Cornell Laboratory of Ornithology

spent ten years
crisscrossing New Guinea

in search of these birds.

There are four species of parotia
and in one, Wahnes's parotia,

they discovered something new.

They placed the camera above
the arena of a displaying male,

and so observed his dance
from a female's point of view.

And it showed two details
of the male's performance

that can only be seen from above.

The pennants on his head,
seen this way,

form a vibrating arc
around his skirt.

Then, iridescent lights appear to
flash across the top of his head,

something you just can't see
from the side.

And the bow tie
of iridescent feathers

has very much more impact
from above.

It is now known how the parotia
breast shield changes colour.

The feathers are arranged
so they overlap like scales,

and each feather has side filaments,

each of which has
three different reflectors -

one that reflects an orange-yellow
colour and two that reflect blue.

And these reflectors
are at an angle to one another,

so as the bird moves,

the breast shield appears to
change colour, like this.

And the parotia family
held yet more secrets,

as Ed Scholes and Tim Laman revealed
when they visited me in Bristol.

Nice to meet you! Where are we going
to sit? Right here. OK.

I can't wait to see this stuff.

They had filmed
the courtship display

of the Queen Carola's parotia,
that I had never seen before.

Oh! I can immediately see it's
different, with those white flanks.

There's a female there...

Oh, yeah. She's much lighter.

There's another at the back.
Oh, yes. Three females now.

Four! They keep coming. Look at
that, look at how intense they are.

Ah! It's starting.
See this figure of eight,

where he's bouncing back
and forth fluttering his wings.

If you were to trace the feathers
on the back of his head,

and slow it down, it would make
a perfect figure of eight.

And they're always perched
above the display?

That's right. It's a really
important part of the court.

The male selects that spot

because it has that perch
for his audience to watch from.

And the audience really knows
where the best place is.

The dance is facing upwards.

Here he is, see this hop and shake.
Hop and shake.

He's transformed himself into
this ballerina-like skirt shape.

He's positioning himself until he
gets right underneath the female.

He goes into that dramatic pause.

All the females are
leaning over, looking at him.

And as soon as he starts moving,
they kind of relax and move as well.

THEY LAUGH

Go for it, boy.

He eventually mated
with all six of those females.

This was the most successful
individual bird of paradise

that we ever saw - this male
was the king of them all.

This pause is terrific, isn't it?

"Come on, girls."

"This is it!"

By 2011, Tim and Ed, after 18
separate expeditions to New Guinea,

had succeeded in filming

every known species of
bird of paradise in the wild.

We have come a long way
from those first attempts

to make drawings of the birds,

which had to be based on no more
than their shrivelled skins.

Then came paintings,
and finally film of them -

eventually in colour.

But, of course,
in the mid-19th century,

the only way to see a living bird

was to travel 8,000 miles
to New Guinea,

because no-one had managed to
bring one back to Europe alive.

It was Alfred Russel Wallace
who once again was the pioneer.

In 1862, he succeeded
in bringing back to England

two living birds of paradise.

The Zoological Society of London,
the London Zoo, gave him ?300.

An astonishing figure -
worth about ?30,000 today.

They were the first
birds of paradise

to be put on display here, and they
were soon the talk of the town.

In 1957, I set off for New Guinea,
not only to film the birds,

but, on behalf of the London Zoo,
to try and bring some back alive.

Although we managed to film
the Count Raggi's bird,

I wasn't able to catch any.

But then I met a great naturalist
and explorer

who had settled in the Wahgi Valley,

and had built aviaries in which
he kept many of the species.

His name was Fred Shaw Mayer.

I found Fred with Bob, his hornbill.

Fred has been collecting animals
all his life,

and in New Guinea alone, he's
discovered five birds new to science

including one bird of paradise.

Fred gave me 13 birds of paradise
of ten different species.

I set out with them on the five-week
journey back to London.

And they ended up here in the
old Bird House in the London Zoo.

It was quite a difficult journey.

We had to charter a little plane to
take us to the island port of Rabaul

off the eastern end of New Guinea,
and there we found an old cargo ship

that ploughed its way across
the South China Sea to Hong Kong.

Every day, of course,
they had to be fed and cleaned,

and we had plenty of fruit,
but we discovered, as Wallace had,

that what the birds really loved
was cockroaches.

And there were plenty of those
to be found in the ship's kitchens.

Then, from Hong Kong, we got
a freight plane back to London.

This big aviary here contains
several of the birds of paradise

which we brought back.

That big one on the left

is the Princess Stephanie's
bird of paradise,

one of the largest
of the birds of paradise.

And here's one of the smallest -
the King bird of paradise,

which is only a little larger
than a robin.

It's a wonderful little bird.

Birds of paradise haven't been seen
here in London Zoo since 1973.

But that's because it's now illegal

to export the living birds
from New Guinea.

Nonetheless, there are just
a very few places in the world

where captive bred ones can be seen.

I'm heading for one of them -

an unlikely location
in the Middle East.

Thousand of miles away from the
birds of paradise's natural home.

A sanctuary has been built
especially for them

by a 21st-century royal collector,

Sheikh Saoud Bin Mohammed
Bin Ali Al-Thani.

Here, in the middle
of the desert of Qatar,

a breeding centre
has been created for rare birds

and animals from all over the world.

The Sheikh has built Al Wabra, a
state-of-the-art breeding facility.

There we are.

What about that?

Here at Al Wabra they are experts
at caring for exotic birds,

like these wonderful
Hyacinth Macaws,

the largest of all flying parrots
and very, very beautiful.

They also maintain the largest
captive breeding group in the world

of birds of paradise,
with over 90 birds.

They get the best possible care,

with particular attention
being paid to their nutrition.

They consume 160 kilos
of papaya a week.

And their favourite insect food
is mealworms.

Twice a day, freshly made,

the meals are delivered to each
of the 90 birds individually.

Curator Simon Mathews
is in charge of the birds,

and his aim is
to understand them better,

and to improve their breeding
success still further.

Because the eggs are so valuable,

Simon removes them from the nests
to incubate them artificially.

This is a very special
and precious chick.

It's a young
greater bird of paradise,

and one of the very, very few
that have been reared in captivity.

And Simon is now giving it
one of its regular feeds.

He has to feed it every two hours,
up to nine times a day

for nearly 20 days.

He whistles
to attract its attention.

It's kept in an incubator
for three weeks.

But the most difficult part of
the breeding process in captivity

is getting the birds to mate
without injuring one another.

In the wild, male plumed birds
form leks, as in Wallace's picture,

where many males gather to show off
their plumes to visiting females.

The female then chooses the male
she admires the most...

..mates with him,
but then quickly leaves,

avoiding the aggression that
the males often show during mating.

The difficulty for Simon

is to ensure that the birds
behave in the same way in captivity.

To protect the females,

he keeps the sexes separately
and in alternate cages.

He watches a female

to see which side of her enclosure
she spends most of her time,

which suggests to him which
of the two males she prefers.

Once she appears to have made
her choice, he opens a hatch.

And then she flies in to briefly
visit her chosen partner.

Although courtship has been
well documented in the wild,

few people have ever witnessed
the birds nesting.

This is something
I have never ever seen before.

I have been so fascinated
by the beauty, drama and glamour

of the males with their splendid
plumage and dances,

I have never spent time
looking for the nest of the female.

And it's very unobtrusive,
and very ordinary-looking.

It looks as though it might even
have been made by a blackbird.

She makes it entirely by herself,

and in it,
she lays her one single egg,

which she will rear
entirely by herself.

Most other species of birds
work together as pairs,

not only to make a nest, but
to collect all the food needed

to rear their young.

And that difference
is important in understanding

why birds of paradise
behave in the way they do.

It's the fact that the female
takes on the laborious business

of caring for the young by herself
that is the clue

as to why the males have evolved
such extravagant plumes.

Over the years,
many naturalists have puzzled

over these fantastic plumes.

Why should this one family of birds

have taken feathered ornaments
to such extreme lengths?

And surely,
having plumes like this

must make it more difficult to fly,

and therefore make a bird
more vulnerable to predators?

That certainly mystified Wallace.

He described the males' displays

as being nothing more than
"playing" or "dancing".

But their real purpose
is much more important than that.

This is a female
King bird of paradise,

and you can see she is very drab.

Nothing like the glorious male.

And it was Charles Darwin
who understood the important part

that she plays in the evolution
of birds of paradise,

because it's she who selects a male

for the beauty of his plumage

and that,
over many, many generations,

has led to the glories of the male.

Darwin called the process
in which a female chooses a mate

based on his physical appearance
"sexual selection".

And the great variety
of male ornaments has evolved

simply because the females of a
species have developed a preference

for a particular kind of plume
or colour.

This trait, then,
over many generations,

becomes more and more exaggerated

until eventually it can reach
almost absurd extremes.

The two magnificent
long, white tail feathers

of the ribbon-tailed
bird of paradise

evolved because
the female ribbon-tails

happen to like
long, white tail feathers.

They are four or five times
the length of the bird's body,

the longest tail feathers, in
proportion to its body, of any bird.

The remarkable thing is that
all these plumes, pennants and capes

have evolved from simple feathers.

Of course, they no longer serve
the original function of feathers,

to keep a bird warm,
or to help it fly.

Indeed, if anything,
they are an impediment to flight.

Their only purpose
is to impress the females.

And it is not only birds
that find such plumes irresistible.

The people of New Guinea
have always been well aware

of the biological purpose
of these extravagant ornaments.

And when a tribesman puts on
gorgeous plumes and feathers

and displays them in dances,

he is using them
for the same purpose -

to display his desirability
so a lady might select him.

DRUMMING

To prepare the skins and plumes,

New Guinea men still carefully
remove the fleshy legs and wings

to reduce the likelihood
of insect attack,

and to better display the plumes.

So the reason it was believed
the birds had no legs

was because they had been removed
before the skins left New Guinea.

But why has this particular
family of birds

been able to take their ornaments
and displays to such great extremes?

The answer lies in the nature
of New Guinea itself.

The island is a relatively new one,

having been pushed up
from the bottom of the sea

a mere ten million years ago -
recently in geological time.

So few land-living mammals
have managed to colonise it,

and most of those
are harmless to birds.

Echidnas,
that live largely on worms,

and a kind of kangaroo

that bizarrely clambers around
in trees, eating leaves.

What's more, the lush,
wet rainforests are rich

all the year round in sugary fruits.

And crucially, because the birds
enjoy such a plentiful

and energy-rich food supply,

a female is able to raise her chick
entirely by herself.

And that frees the males to spend
a lot of time and energy

producing extravagant adornments
and spectacular displays.

So, fruit, that plays
such a significant role

in the Biblical view of paradise,

has also created a paradise
for these birds.

Perhaps the name is apt after all.

It's now known that the complexity
of a bird-of-paradise display

does not come entirely naturally,

as Ed Scholes has recently observed
in young male riflebirds.

They start spending more and more
time practising their displays.

Riflebirds are using their wings,
moving them back and forth,

creating this interesting shape.

Taking a turn at being the male
doing the practices,

and the other one
is taking the role of the female.

Then they alternate.

And sometimes they're going on
like this for hours,

and getting very carried away.

But when an adult male turns up,
he sends them on their way.

And it's not only riflebirds
that have to learn to dance.

Young male parotias
start visiting display courts

when they're three years old,

before they develop
the black plumage of the adult.

And they use this time
to practise their dance moves.

It will be several more years

before this one will be
taken seriously by a female.

It makes them look like a teenager,
kind of strutting his stuff

in front of the mirror when he's
not quite fully developed yet.

For five centuries,

birds of paradise have fascinated
explorers and naturalists,

artists and collectors.

So it was a very special moment
for me to get so close when,

because he had been hand-reared,

this male bird-of-paradise
actually began to court me.

This surely is one of the great
wonders of the natural world,

just as Magellan's sailors
said it was 500 years ago -

even though, in fact,
the bird does have legs.

The displays
of the birds of paradise

have at last been recorded,
both on canvas and on screen,

in all their exquisite detail
and complexity.

Now, at last, we understand

that it is the rich character
of their island home

that has allowed the birds to evolve
in the ways that they have.

And it's the female's preference

for particular patterns,
colours and displays

that have led to
the males' astounding finery,

making them, surely,

among the most stunning
and glamorous birds on Earth.

Millions of us watch clips of animals

showing what looks like
friendship, affection