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