All language subtitles for David.Attenboroughs.Natural.Curiosities.Series.3.2of6.Curious.Minds.720p.HDTV.x264.AAC.MVGroup.org

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The natural world is
full of extraordinary

animals, with amazing
life histories.

Yet, certain stories are
more intriguing than most.

The mysteries of a
butterfly's life cycle,

or the strange biology
of the Emperor penguin.

Some of these creatures
were surrounded by myth

and misunderstandings,
for a very long time.

And some, have only recently
revealed their secrets.

These are the animals, that
stand out from the crowd,

The curiosities, I find
particularly fascinating.

Orang-utans have an extraordinary
ability to use tools.

But the full extend of their skills,
remained undiscovered for centuries.

Surprisingly, crows
also make tools.

How and why have these two very
different animals become so inventive?

When I first saw Orang-utans, that
had been raised in captivity,

using tools, I was
truly astonished.

They were extraordinarily skillful,
at imitating the things we do.

But at the time, such
skills had never

been observed among
wild Orang-utans.

So, are these apes
just clever mimics,

or do they ever make, and
use tools in the wild?

We didn't know the answers to such
questions, until quite recently.

This dramatic sculpture, by the

French artist Emmanuel Frémiet,

entitled: An Orang-utan
strangling a Borneo native,

represented the image, people had
of this formidable giant ape.

It's pretty accurate,
as Frémiet studied live

Orangs at the Jardin
des Plantes in Paris,

and you can see, why
Orangs are so called.

The name in Malay means, Orang -
people and utan - of the forest.

At first, Orang-utans were
feared and misunderstood.

Early explorers thought, that these
long-armed, tree-living apes,

were degenerate human beings.

And for centuries,
their true nature and

behaviour in the wild,
was largely unknown.

Orang-utans are only found in
the rainforests of Indonesia.

One population in
Borneo, and another,

slightly different one, in the
island of Sumatra to the west.

They have strong,
dextrous hands and feet,

and a very mobile mouth,

that enable them, to break open and
eat the fruits, on which they depend.

But although they are
clearly very intelligent,

the only tools they seemed
to use were sticks,

which they wielded,
in a very simple way.

Yet, in Africa, chimpansees
had been seen,

using tools in a rather
more complex fashion.

Back in 1871, Darwin had
reported, wild chimpansees,

cracking open walnut-like
fruits with stones.

And in the 1960's they
were even seen modifying

sticks, with which they
fished for termites.

It seems strange, that while
wild chimps use tools in a quite

complicated way, Orang-utans,
apparently did not.

Orangs, unlike chimps,
are not very sociable.

Individuals are
largely solitary.

The males have large,
individual territories,

within which, several females
have their own home ranges.

This, more solitary way
of life, affects they way

orangs share their knowledge
and develop their skills.

The most social time of an Orang-utan's
life is, when it's a baby.

And in the wild, youngsters
stay with their mothers,

for the first 6
years of their lives.

During this time, they
learn the skills needed,

to survive in the forest alone.

They need to know how to
climb, and build nests,

And how to solve problems, such
as breaking into tough food.

And their large brains serve them,
to help them, to master these tasks.

So, a young Orang behaves
like its mother,

and copies the way she searches
for food and prepares it to eat.

In captivity, they
readily make tools,

to reach food, or to escape
from their enclosures.

They're clearly very
inventive, and good at

developing ways, to solve
particular problems.

So, it was a puzzle, as to why
such bright and capable apes

were apparently not behaving
in a similar way in the wild.

Orangs are clever, and
physically dextrous.

They've very strong jaws
and mobile hands and feet,

and in the wild, they can reach
and prize open most food.

It was assumed for many years,
that even though they used tools

in captivity, they didn't perhaps
need to do so, in the wild.

It seems that, strangely, these
great apes, have more skills,

than they normally need, for
their lives in the wild.

It wasn't until 1964, that
orangs were studied in detail.

A Lithuanian scientist from
Canada, called Biruté Galdicas,

settled in Borneo, to live
alongside these great apes.

For over 30 years, she
watched both tame orangs

and wholly wild ones,
in the forests.

In her camp, she found that the
tame ones quickly discovered

how to use tools, in a
relatively sophisticated way.

But in the wild, she only
saw them build nests

and use sticks, in
a simple fashion.

That picture of the character
and abilities of orangs,

remained unchanged
for a long time.

Then, in 1994, our understanding
of orangs changed radically.

A group of Swiss scientists
observed some orangs,

that were behaving
very differently.

They lived several hundred miles
away, from their Borneo cousins,

in swampy rainforests, on
the island of Sumatra.

The orang's diet is
about 90 percent fruit,

and this is one of
their favorites.

It's a durian, and it's
well known ...

..for it's pungent smell.

As you can see, it's got
a very spiky case.

But orangs are able
to break it open

and reach the soft,
pulpy flesh inside.

But its when they tackle
another, similar spiky fruit,

called nisia, which is
more difficult to open,

the scientists got their first
glimpse of orangs making tools.

Nisia presents an extra
challenge, because

inside it contains rich,
nutritious seeds,

which are embedded in a mass
of sharp, needle-like hairs.

To avoid catching these
irritating hairs,

the swamp-living
orangs slid sticks

in the cracks in
the fruit's husks.

Then they push them up and down,

to flick out the hairs
and free the seeds.

They also modified sticks,

so that they fitted different
sized cracks in the fruits.

The particular fruit, that
grew in these wet forests,

had stimulated the Sumatran orangs,
to make a new special tool.

Unusually for such
solitary creatures,

they gathered at these rich
feeding areas in a group.

And feeding close to one another,
they share their skills.

So now it was realised, that
orangs were not just mimics.

They were able to
invent their own ways,

of making and using
tools, just like chimps.

We have long known,
that captive orangs

can quickly work out
ways, to solve problems.

And now, it was clear, that
wild orangs are no different.

In recent years, they've
been seen, using sticks,

to fish for termites and
honey, in much the same way

as individuals do in captivity.

In the flooded forests,
many insects are

forced above ground to
live in tree holes.

So the orangs use sticks,
to extract them.

It seems incredible, that
tool-using wild orangs

took hundreds of
years to discover.

In fact, it has been
happening all the time,

just hidden away from view.

These red men and
women of the forest,

have very dextrous
hands and feet,

strong jaws, and a large brain.

In the wild, they have little
need for complex tools,

and being solitary
means, that tool use

is not usually shared or spread.

But even as loners,
they are inventive

and can work out how
to solve problems.

Here is a creature,
that could be

one of the greatest tool
users in the animal kingdom.

Next, we meet the crows,

a family of clever birds,

with a knack for solving
tricky problems.

Orang-utans make and use
quite simple tools.

And crows make tools too.

How and why have crows
become so inventive?

The most famous members of
the crow family in Britain,

are the ravens, that live
here, in the Tower of London.

By tradition, they
protect The Crown.

And they are recruited,
and indeed dismissed,

from the British Army,
just like soldiers.

In 1986, one of them,
called George,

had to be exiled to Wales,
for persistent bad behaviour

in destroying the television
aerials around here.

And more recently,
another one, noticing

that one of its fellows had died

and was attracting a
great deal of attention,

also laid down on the
ground, feigning death.

And when the Raven
Master came over to see

what the matter was,
he got a sharp peck.

Well, stories like
those suggest,

that members of the crow family

have minds, rather different
from other birds.

Ravens are cheeky, self-aware,
and socially intelligent.

They are part of the big crow
family, which in Britain includes:

Hooded and Carrion
crows, Jackdaws,

Jays, Choughs and Magpies.

Their brains are twice
as large as other birds,

and relative to body size,
comparable to a chimpanzee's

This extra brain capacity,
has helped them

become very good at
solving problems.

Here is Bran, the raven.

And I put a screen in
front of his cage,

so he can't see what's going on.

And this is Bran's stone.

He's had it, since
he was a chick,

and he can recognize it,

amongst a whole pile
of other pebbles.

Now, I've put a few, of a
similar size, on this grid.

And I'll put his
stone just there.

And now, we'll see,
whether he can find it.

Bran, where's your stone?

Immediately.
Well done. Hahaha.

The only explanation
of this is ...

... that he has an extremely
acute visual memory.

Indeed he has.

You could say, that
by putting stones

on a gridded square like that,

makes each one very obvious.

Alright, well, let's make
things a little more difficult.

This is his stone,

and I'll put it in this..
..pile of stones,

so that he can only see
just a little tip of it.

Now Bran, where's your stone ?

Oh, come on.
Hahahahaha.

Fantastic.
Thank you very much.

And this ability, to recognize
a little, small detail,

is used by these birds,
when they cash food.

In the good times,
they will hide

hundreds of different
pieces of food,

and conceal them, and
remember every one.

And come back to it,
in the hard times,

to pick up that piece of food.

Extraordinary.

You're an amazing bird, Bran.

Another species of crow,
Clark's nutcracker,

is a champion of cashing food.

It collects and hides up to
33,000 seeds every season,

and remembers where each one
is put, for up to nine months.

It can even find
them under snow.

Crows also remember the kind of
food, that they have hidden.

Freshly buried grubs,
perish quickly,

so need to be recovered
sooner than seeds.

The ability to think ahead,
and anticipate future events

can also help in
other situations.

Other birds will steal buried
food, if they can find it.

but some kind of crows are able to
recognize these thieves, and outwit them.

Recent research at Cambridge,
has revealed that Scrub Jays

take great care, in how
they hide their food.

One jay is given the choice of two
locations in which to cash food.

Under stones, which make a
noise if they are moved,

or soil, which can be
cleared away quietly.

In the case next-door,
another scrub jay watches.

He is a potential thief.

When the cashing jay knows,
that its neighbour can see,

it buries its food under stones.

If the jay next-door attempts
to steal that buried food,

the noisy stones will act
like a burglar alarm.

But when a screen is
added, so that the

neighbouring jay, can only
hear what's happening,

the cashing jay
changes its plan.

This time, it decides to
bury its food under soil,

which makes hardly any
noise, so its location

remains unknown to
the jay next-door.

For centuries, members
of the crow family

have been recognised
to be unusual birds.

Their noisy gatherings gave
them a sinister reputation.

But their intelligence
was legendary.

In one of Aesop's
Fables, a clever crow

drops pebbles into
a jug of water,

to raise the level high
enough, so that it can drink.

This is perhaps one
of the first recorded

examples, of a
crow using a tool.

Here, once again,
is Bran the raven.

And like the crow
in Aesop's Fable,

he is extremely intelligent, and
clever, at collecting food.

I'm gonna set him a problem,
which he has seen before,

and for which, he produced
his own solution.

I'm going to take a
little bit of meat,

put it in this plastic bottle,

and then, just to make
it difficult for him,

I'm gonna crush the bottle

so that it won't come
out, just by shaking it.

Now then Bran,

how are you gonna get that out?

Hahaha hahaha

What he did,

was to take this bottle,

put it in the water, and use

the water to swill it out

and take the bit, and he did

that in about 10 seconds flat.

Bran, in effect, used
the water as a tool.

And he is very quick, to understand
the potential of any object

and work out how it might help
solve one of his problems.

All crows, it seems, have
extraordinary memories,

acute vision and great
ingenuity in devising tools.

In New Caledonia, a tropical
island, east of Australia,

wild crows use tools, just as
expertly and inventively as apes.

They fashion sticks, to tease
grubs out from places

they would otherwise find
impossible to reach.

More recently, scientists
discovered and filmed crows,

that had taken their
toolmaking a stage further.

They were creating
hooks, by carefully

modifying the thick
ends of twigs.

This seemed extraordinary.

But there were more surprises.

On the nearby island
of Grand Terre,

the crows were making even
more sophisticated implements.

These are the actual tools,

made by New Caledonian crows.

They're constructed from the
leaves of the Pandanus tree,

which have lines
of sharp spikes,

along their margins.
And the crows use them,

to winkle insects
out of crevices.

But each population
of these crows,

makes the tool in their own way.

This one is a broad strip,

This one, a very thin strip.

And these two, which come
from the north of the island,

are used by two
different populations.

One, makes a two-step,

tool, thin at the end,

and this one, makes a one
- two - three step tool.

In this rare footage, the crow strips
off the serrated edge of a leaf.

The series of small spines are
better than just a single hook

because they can snag an
insect along all its length.

Each population of the crows,
have their own design,

which they pass on, to
the next generation.

So, just like us, these
New Caledonian crows,

have their own cultures.

Their own inquisitive,
curious minds.

Which is pretty
unusual, for a bird.

Orang-utans in the wild,
make very simple tools.

But surprisingly,
it's the smart crows

that take the prize, for making the most
sophisticated tools used by any animal.

Very clever.

Are we finished now?

Where is my lunch?