David Attenborough's Natural Curiosities (2013) s03e02 Episode Script
Curious Minds
1 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?
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?