0:00:05 > 0:00:10For centuries, we thought animals were creatures of pure instinct,
0:00:10 > 0:00:13with no understanding of how the world works.
0:00:15 > 0:00:18Simple beasts with simple minds.
0:00:20 > 0:00:23We thought that only we humans could actually think,
0:00:23 > 0:00:28analyse, reason, use imagination and solve problems.
0:00:31 > 0:00:34But new scientific research is revealing there is
0:00:34 > 0:00:38a small group of animals with extraordinarily clever minds -
0:00:38 > 0:00:42octopus, great apes
0:00:42 > 0:00:45and even some birds.
0:00:45 > 0:00:47It's a bizarrely diverse group.
0:00:48 > 0:00:52But they share a remarkable ability to analyse
0:00:52 > 0:00:55and solve problems in a very human-like way.
0:00:55 > 0:00:58I want to get inside these animals' minds
0:00:58 > 0:01:00and see just how clever they are.
0:01:03 > 0:01:08Starting with perhaps the cleverest of all - the crow family.
0:01:08 > 0:01:12How on earth did that crow do that?
0:01:14 > 0:01:17I want to push them to the limit, to find out how
0:01:17 > 0:01:22they measure up to other animals that we think are pretty clever.
0:01:22 > 0:01:25All you've got to do is lift the ball!
0:01:25 > 0:01:29I'll discover what makes some animals capable of brilliant
0:01:29 > 0:01:33ingenuity that seems almost human.
0:01:33 > 0:01:35It's a sort of Satnav for bees.
0:01:37 > 0:01:41I want to uncover why this special group of animals
0:01:41 > 0:01:44have such superb problem solving minds.
0:01:45 > 0:01:49Now, if we can do this, we might just unlock one of nature's
0:01:49 > 0:01:54greatest mysteries - how we ourselves came to be so clever.
0:02:12 > 0:02:15Welcome to a lost world.
0:02:18 > 0:02:21The island of New Caledonia.
0:02:26 > 0:02:30Lying nearly 1,000 miles east of Australia, it is a tropical
0:02:30 > 0:02:37paradise, bursting with exotic life found nowhere else on the planet.
0:02:41 > 0:02:46I'm here to find one of these unique animals.
0:02:46 > 0:02:49It has an almost legendary status,
0:02:49 > 0:02:53thanks to an amazing ability to solve problems.
0:02:55 > 0:02:59The animal that I am looking for is truly remarkable.
0:02:59 > 0:03:03The problem is, it is very, very difficult to find.
0:03:03 > 0:03:05It's cunning. And it's quick.
0:03:05 > 0:03:07Agile.
0:03:08 > 0:03:11If I'm honest with you, there could be one right here somewhere,
0:03:11 > 0:03:15just looking down at me, and I've never ever seen one.
0:03:23 > 0:03:28Many experts think that these are the cleverest animals on earth.
0:03:28 > 0:03:32I've been told I might see that intelligence in action
0:03:32 > 0:03:34on the island's high mountain roads.
0:03:37 > 0:03:41It is this - a crow.
0:03:41 > 0:03:44But not just any crow.
0:03:44 > 0:03:47This is the New Caledonian crow.
0:03:47 > 0:03:51It is not the same species we find a Britain.
0:03:51 > 0:03:53These are jungle birds.
0:03:53 > 0:03:56And here, in isolation on the island,
0:03:56 > 0:03:59they have evolved some remarkable abilities.
0:03:59 > 0:04:03This one is holding a nut in its claw.
0:04:04 > 0:04:06It drops it onto the tarmac,
0:04:06 > 0:04:09seemingly to crack open the hard shell.
0:04:10 > 0:04:16But in truth, it is what the bird does next that is really ingenious.
0:04:16 > 0:04:18Now, look at this, this is interesting because,
0:04:18 > 0:04:21having broken the nut open on the road,
0:04:21 > 0:04:25these birds are then carrying it to the Armco here,
0:04:25 > 0:04:29where there are small depressions, man-made cuts, in it.
0:04:29 > 0:04:33And they're using these as a vice to stop the nut from rolling
0:04:33 > 0:04:37around whilst they access the fruit on the inside of it.
0:04:37 > 0:04:41Now, that strikes me as pretty clever.
0:04:41 > 0:04:45But the question is, of course, just how clever are these birds?
0:04:49 > 0:04:52To find out, I have come to visit Dr Alex Taylor
0:04:52 > 0:04:55at his field aviary here on the island.
0:04:58 > 0:05:00To study how these birds solve problems,
0:05:00 > 0:05:04he has put a tasty morsel of food deep in a container.
0:05:04 > 0:05:08He is testing whether they can work out how to reach it
0:05:08 > 0:05:12using a variety of objects he has pleased in the aviary.
0:05:12 > 0:05:16But first, he is trying his puzzle out on me.
0:05:16 > 0:05:19Imagine that you are a crow.
0:05:19 > 0:05:22Here is your food, in a deep hole. How would you go about,
0:05:22 > 0:05:24with the tools available to you on this table,
0:05:24 > 0:05:25solving this problem?
0:05:28 > 0:05:30- This is part of it, obviously.- Mm-hm.
0:05:30 > 0:05:36At my disposal, I have a short stick on a piece of string,
0:05:36 > 0:05:39three stones inside the cages...
0:05:40 > 0:05:43..and a longer stick trapped in a box.
0:05:43 > 0:05:48Which means, then, that the crow is going to use this stick...
0:05:51 > 0:05:55- ..to get the stones out of there. - Absolutely.
0:05:55 > 0:05:58Next, the crow needs to drop the stones onto a trap door
0:05:58 > 0:06:01to release the long stick.
0:06:01 > 0:06:03It is going to need all three stones.
0:06:03 > 0:06:08And then it probably will drop that one out. Excellent.
0:06:08 > 0:06:13And using this long stick, it will finally be able to reach the food.
0:06:15 > 0:06:18This is a tough one. All right, can I stay in here?
0:06:18 > 0:06:21- Absolutely, you can sit and watch. We will see what happens.- Come on, then.
0:06:21 > 0:06:24Send in your mastermind, because it is going to need that.
0:06:26 > 0:06:28Alex studies wild birds,
0:06:28 > 0:06:31which he releases after three months of research.
0:06:33 > 0:06:36This one is nicknamed 007,
0:06:36 > 0:06:40and it is about to attempt what Alex believes is one of the most
0:06:40 > 0:06:45complex tests of the animal mind ever constructed.
0:06:45 > 0:06:49The bird is familiar with the individual objects,
0:06:49 > 0:06:54but this is the first time he has seen them arranged like this.
0:06:56 > 0:07:01Eight separate stages that must be completed in a specific order
0:07:01 > 0:07:03if the puzzle is to be solved.
0:07:03 > 0:07:08And if the bird succeeds, it will be a world first.
0:07:08 > 0:07:14He takes time to have a look and then starts with the short stick.
0:07:19 > 0:07:20Stage I.
0:07:25 > 0:07:28He finds it is too short to reach the food.
0:07:29 > 0:07:32He then sets off to get the first stone.
0:07:40 > 0:07:42But he drops it.
0:07:56 > 0:07:59And another. He seems to be stuck.
0:08:03 > 0:08:07But then something seems to click.
0:08:08 > 0:08:10He deploys the first stone.
0:08:24 > 0:08:26And then another.
0:08:44 > 0:08:46Got it!
0:08:48 > 0:08:50The eighth and final stage.
0:08:57 > 0:08:59Success!
0:08:59 > 0:09:04Eight individual stages of one complex puzzle completed.
0:09:07 > 0:09:10That was remarkable.
0:09:10 > 0:09:14I've never ever seen anything like it.
0:09:14 > 0:09:19Of all of the bird behaviour I've seen, nothing matches that.
0:09:19 > 0:09:20I can hardly believe it.
0:09:20 > 0:09:23I'm still just running that sequence through my mind.
0:09:23 > 0:09:25It happened really quickly.
0:09:25 > 0:09:28But the immediate question is, of course,
0:09:28 > 0:09:32how on earth did that crow do that?
0:09:34 > 0:09:36You see, on the face of it,
0:09:36 > 0:09:40the crow's problem-solving abilities seem mind boggling.
0:09:44 > 0:09:48But look close enough and the natural world is filled with
0:09:48 > 0:09:51examples of animals behaving in clever ways.
0:09:56 > 0:10:01The spider spins a web that gets stronger when it catches prey.
0:10:01 > 0:10:05It's precision engineered to catch flies.
0:10:07 > 0:10:12Turtles navigate through thousands of miles of featureless ocean,
0:10:12 > 0:10:16returning every year to the same beaches to lay their eggs.
0:10:18 > 0:10:22It is as if they hold a nautical map in their heads.
0:10:24 > 0:10:27So are the clever crows really so unusual?
0:10:30 > 0:10:32Well, to find out,
0:10:32 > 0:10:37I need to investigate how animals solve problems.
0:10:40 > 0:10:43And I am starting back in Britain with the honeybee,
0:10:43 > 0:10:48a small animal that seems to be able to do something staggeringly clever.
0:10:50 > 0:10:52The pollen and nectar that bees eat
0:10:52 > 0:10:56is clearly only available whilst the flowers are in bloom,
0:10:56 > 0:10:58so it's there throughout the spring and the summer.
0:10:58 > 0:11:01But the bees have to get enough of it
0:11:01 > 0:11:04so that the hive can make it through the winter.
0:11:04 > 0:11:08And frankly, if that isn't a massive task, then I don't know what is.
0:11:11 > 0:11:15But the bees have an almost incredible solution.
0:11:15 > 0:11:19To see with that is, I have come to meet Professor Adam Hart.
0:11:20 > 0:11:22- Hello, Adam.- Hi, Chris.
0:11:22 > 0:11:26One of his specialisms is the hidden world of the honeybee.
0:11:26 > 0:11:29That is a very intimate view of the interior of the hive.
0:11:29 > 0:11:32- Yes, it's like Big Brother for bees. - It is! It's great, isn't it, really?
0:11:34 > 0:11:38Adam has set up an infrared camera to spy on the bees inside the hive.
0:11:40 > 0:11:45And we are hoping to see a striking behaviour that is key to
0:11:45 > 0:11:48solving the problem of gathering enough food.
0:11:48 > 0:11:51It is called the waggle dance.
0:11:53 > 0:11:56Adam, look at this one. This one is waggle dancing, isn't it?
0:11:56 > 0:11:57Yeah, this is the waggle dance.
0:11:57 > 0:12:00You have got this lovely figure of eight dance,
0:12:00 > 0:12:03sometimes getting in the way of other bees, but generally speaking,
0:12:03 > 0:12:05keeping this nice kind of rhythm going.
0:12:08 > 0:12:12The waggle dance isn't just for show.
0:12:12 > 0:12:17This bee has found a good source of food, and she is performing
0:12:17 > 0:12:20a set of very precise movements to tell the others
0:12:20 > 0:12:22exactly where to find it.
0:12:24 > 0:12:29And this is all about communicating the whereabouts of a food source.
0:12:29 > 0:12:31Yeah, this is like GPS for bees, basically.
0:12:31 > 0:12:34They are telling other bees not just that there is food out there,
0:12:34 > 0:12:36which is quite a useful signal, but where that food is.
0:12:36 > 0:12:40So they can communicate the direction and the distance of that nectar.
0:12:43 > 0:12:48But how can a dance communicate where a food source is?
0:12:54 > 0:12:59To find out, we need to get a better view of the horizon.
0:13:04 > 0:13:06- Super view, well worth the climb.- Yeah.
0:13:06 > 0:13:08But what about the mechanics of this dance, then?
0:13:08 > 0:13:11The bee we saw in the hive was doing this figure of eight,
0:13:11 > 0:13:13and that central section was where she was vibrating her abdomen.
0:13:13 > 0:13:16When you think about it, the only frame of reference bees have
0:13:16 > 0:13:17in the hive is gravity, up and down.
0:13:17 > 0:13:20The frame of reference they have out here is the position of the sun,
0:13:20 > 0:13:23or more accurately, where the sun would be if it was projected down
0:13:23 > 0:13:26on the horizon, what is called the azimuth.
0:13:27 > 0:13:30From up here, it is easy to see where the sun lies over
0:13:30 > 0:13:36the landscape and where it would be if it dropped to the horizon.
0:13:36 > 0:13:42Now, our dancing bee was waggling at an angle of five degrees.
0:13:42 > 0:13:45So, if this tower were a massive beehive,
0:13:45 > 0:13:50the waggle dance would be telling us that the nectar is five degrees
0:13:50 > 0:13:52from the relative position of the sun.
0:13:52 > 0:13:55That is somewhere in that direction.
0:13:57 > 0:14:00All right, that is the direction, what about the distance?
0:14:00 > 0:14:03That's that duration of that central waggle run, as it is called.
0:14:03 > 0:14:05The longer they dance for, the longer that waggle run goes on for,
0:14:05 > 0:14:07the farther away the food is.
0:14:07 > 0:14:09So, a very short waggle run, like we saw down in the hive,
0:14:09 > 0:14:12is maybe a couple of kilometres, whereas they can sometimes
0:14:12 > 0:14:16waggle for much longer, perhaps nine, ten kilometres even.
0:14:17 > 0:14:20So, honeybees survive the winter
0:14:20 > 0:14:24by using what we'd call mathematics.
0:14:24 > 0:14:26They compute angles and distances
0:14:26 > 0:14:30and then communicate that information to their nest mates.
0:14:34 > 0:14:38It seems incredibly clever, but in fact,
0:14:38 > 0:14:41it doesn't involve any thought at all.
0:14:41 > 0:14:46You see, the waggle dance is so important to the survival
0:14:46 > 0:14:50of the hive, that it comes built into the brain of the honeybee.
0:14:50 > 0:14:52Every worker bee is born
0:14:52 > 0:14:57with the ability to perform the dance automatically.
0:14:58 > 0:15:03In other words, the bees are acting on instinct -
0:15:03 > 0:15:04a set of behaviours
0:15:04 > 0:15:07that are so important to the animal's survival
0:15:07 > 0:15:10that they are hard wired.
0:15:10 > 0:15:14Think of them as a simple set of rules that are tattooed
0:15:14 > 0:15:17onto its genes by evolution.
0:15:17 > 0:15:20It is what makes these bees do the waggle dance.
0:15:20 > 0:15:23The animals have no real understanding
0:15:23 > 0:15:25of what they are doing.
0:15:27 > 0:15:30But what about our New Caledonian crow?
0:15:30 > 0:15:36It solved a complex eight-stage problem.
0:15:36 > 0:15:41Is it really possible that the bird was acting only on instinct,
0:15:41 > 0:15:45without any real understanding of what it was doing?
0:15:45 > 0:15:49In short, the answer is no.
0:15:49 > 0:15:53Because, unlike bees with their waggle dance, these birds are not
0:15:53 > 0:15:59dependent on solving a multistage puzzle in order to survive,
0:15:59 > 0:16:02for the very simple reason that you don't find multistage
0:16:02 > 0:16:06puzzles like this out there in the wild. They are not natural.
0:16:06 > 0:16:09They are a man-made artefact.
0:16:09 > 0:16:14And for that very obvious reason, there is no chance whatsoever
0:16:14 > 0:16:19that these birds could have evolved an instinct to solve them.
0:16:19 > 0:16:23But solve them they do. So if it isn't instinct, what is it?
0:16:25 > 0:16:29To begin to discover what is really going on in the crow's mind,
0:16:29 > 0:16:32I have come to Somerset to meet Lloyd Buck.
0:16:32 > 0:16:35He handles birds for TV and film.
0:16:36 > 0:16:38And this is Bran.
0:16:38 > 0:16:43He is a raven, one of the largest members of the crow family,
0:16:43 > 0:16:45a group known as the corvids.
0:16:48 > 0:16:51Oh, what a stunner!
0:16:54 > 0:16:56Hold my finger.
0:16:56 > 0:16:57Are you going to do it again?
0:16:57 > 0:16:59No, he just wants... Oh, ups, sorry.
0:17:01 > 0:17:04You want to hold my finger? No.
0:17:04 > 0:17:07You like that camera, it's the highest point.
0:17:07 > 0:17:11Bran is clearly a bird who knows his own mind.
0:17:11 > 0:17:14In fact, it is hard to know who is in charge.
0:17:16 > 0:17:19Myself and my dogs, you know, I am the pack leader.
0:17:19 > 0:17:21What about you and Bran, who's boss?
0:17:21 > 0:17:24Oh, well, I think obviously Ban.
0:17:24 > 0:17:26But as far as he is concerned, I am his mate.
0:17:26 > 0:17:29- Right. His mate?- Yeah. - His partner?- His partner.
0:17:29 > 0:17:31It is going to be a long-term relationship
0:17:31 > 0:17:33because they're a long-lived bird, aren't they?
0:17:33 > 0:17:38Yeah, in captivity up to 40, 50, even 60 years.
0:17:38 > 0:17:39- He is going the distance with you. - Yeah.
0:17:39 > 0:17:42And they are really time intensive.
0:17:42 > 0:17:45You can't just forget him and leave him in his aviary.
0:17:45 > 0:17:48He likes to go out for his fly, his walk every day.
0:17:48 > 0:17:50He wants to see, he wants to spend time with you.
0:17:50 > 0:17:52Cos they are so intelligent.
0:17:53 > 0:17:56To keep his demanding bird occupied,
0:17:56 > 0:17:59Lloyd likes to set Bran difficult problems to solve,
0:17:59 > 0:18:01like this one.
0:18:02 > 0:18:06Lloyd places a piece of food inside a plastic bottle
0:18:06 > 0:18:09and then crushes it.
0:18:09 > 0:18:13- And you give him a bowl of water. - A bowl of water?- Yes.
0:18:17 > 0:18:21With the bottle crushed, the food is trapped behind the restriction.
0:18:21 > 0:18:24But this doesn't stop Bran.
0:18:27 > 0:18:29First, he adds water.
0:18:32 > 0:18:34Next, he spins it,
0:18:34 > 0:18:38and the liquid carries the food past the restriction and out.
0:18:40 > 0:18:43That is a clever piece of problem-solving.
0:18:47 > 0:18:51Oh, he's got it. He's got it!
0:18:51 > 0:18:53Honestly!
0:18:53 > 0:18:57What about that? Now, that is impressive.
0:18:57 > 0:19:00The thing is, Lloyd, how long did it take him to work that out?
0:19:00 > 0:19:02Well, presented with the crushed bottle,
0:19:02 > 0:19:04it took him basically an afternoon.
0:19:04 > 0:19:08He got frustrated, he couldn't work it out initially, and he left it.
0:19:08 > 0:19:09So we left it with him in his aviary
0:19:09 > 0:19:11and we went up to the house for lunch.
0:19:11 > 0:19:16Come back down in the afternoon and, lo and behold, the food was gone.
0:19:20 > 0:19:24But let's not forget that Bran is a tame raven.
0:19:24 > 0:19:28Aren't you a clever boy? Yes, you are.
0:19:28 > 0:19:31It is possible that, in spending so much time with humans,
0:19:31 > 0:19:35he has been able to observe and copy some of their actions.
0:19:36 > 0:19:40You are too clever for your own good half the time, that is your problem.
0:19:40 > 0:19:43So, I'm going to set Bran a new challenge,
0:19:43 > 0:19:46one that he has never seen before.
0:19:46 > 0:19:48And this time,
0:19:48 > 0:19:52I am going to pit his intelligence against another animal,
0:19:52 > 0:19:54one that we tend to think is pretty clever,
0:19:54 > 0:19:57certainly brighter than birds -
0:19:57 > 0:19:58the dog,
0:19:58 > 0:20:03or to be more precise, my dogs - Itchy and Scratchy.
0:20:03 > 0:20:08- Amongst the dogs, poodles are about the smartest.- Are they?- So they say.
0:20:08 > 0:20:11Bran, he just finished War And Peace.
0:20:11 > 0:20:13- LAUGHTER - I can see how this is going to go.
0:20:16 > 0:20:18To make things even more interesting,
0:20:18 > 0:20:21I am also going to put the same test to Fletcher here,
0:20:21 > 0:20:23who is two and a half,
0:20:23 > 0:20:26which incidentally is nearly the same age as Bran.
0:20:29 > 0:20:34They are all going to face this - a puzzle box of my own design.
0:20:34 > 0:20:36Here's how it works.
0:20:38 > 0:20:41The prize is in the green ball in the centre.
0:20:41 > 0:20:45But to get to it, they firstly have to pull this drop door down here.
0:20:45 > 0:20:50And then, pull this smaller box out.
0:20:50 > 0:20:55And then, remove the lid from that
0:20:55 > 0:20:56to get the ball.
0:20:56 > 0:20:58Simple, isn't it?
0:20:58 > 0:21:00Well, let's find out.
0:21:01 > 0:21:03We've given all of our contenders
0:21:03 > 0:21:07the chance to familiarise themselves with parts of the puzzle box.
0:21:11 > 0:21:14As usual, Lloyd leaves Bran to it.
0:21:16 > 0:21:19Fletcher is also showing an interest in how it works.
0:21:21 > 0:21:22Itch, concentrate.
0:21:22 > 0:21:26'Whereas I need to be a bit more hands-on.'
0:21:26 > 0:21:27Now, look, look.
0:21:29 > 0:21:31Pull that. What this. Look, watch.
0:21:31 > 0:21:35This is the sort of thing my mother would have done. Look, watch.
0:21:38 > 0:21:40That's your lesson over for today.
0:21:42 > 0:21:44And now, the moment of truth has come.
0:21:44 > 0:21:49The contenders are about to face the test proper for the first time.
0:21:49 > 0:21:54This is raven versus dog versus human.
0:22:02 > 0:22:04Itchy, solve this.
0:22:07 > 0:22:09Solve that. OK? I'll be back. Solve it.
0:22:14 > 0:22:19And that, I'm afraid to say, is an emphatic win for Bran
0:22:19 > 0:22:21and all of his corvid kind.
0:22:24 > 0:22:27In truth, my dogs didn't even seem to realise there was
0:22:27 > 0:22:31a problem to solve, despite all of my training efforts.
0:22:32 > 0:22:36And Fletcher, well, he played around with the box a bit,
0:22:36 > 0:22:38but soon seemed to lose interest.
0:22:38 > 0:22:43Whilst Bran was so quick that we will have to use a high-speed
0:22:43 > 0:22:46camera just to see how he did it.
0:22:49 > 0:22:50So the question is,
0:22:50 > 0:22:55why are ravens like Bran able to solve problems on their own when
0:22:55 > 0:23:01other species, including clever dogs and even young humans, can't.
0:23:14 > 0:23:16To find out what abilities the corvids have
0:23:16 > 0:23:20that other animals seem to lack, I have come to Cambridge
0:23:20 > 0:23:22to meet Professor Nikki Clayton.
0:23:22 > 0:23:25She is a world expert on the crow family,
0:23:25 > 0:23:29which includes these Eurasian jays.
0:23:29 > 0:23:33She sets up experiments to break down the different abilities
0:23:33 > 0:23:36that these birds use to solve problems.
0:23:36 > 0:23:40And she set one of them, Hoy, a fiendish challenge.
0:23:41 > 0:23:44One that wouldn't be out of place in a physics lesson.
0:23:45 > 0:23:49She has dropped some wax worms, his favourite food,
0:23:49 > 0:23:51into a tube of water, out of reach.
0:23:51 > 0:23:56So the bird needs to work out how to raise the water level.
0:23:59 > 0:24:02Nikki, let's see what's going on, then.
0:24:02 > 0:24:04- Fire up the laptop and see what he is up to.- I will do.
0:24:05 > 0:24:08Nikki's birds have minimal human contact,
0:24:08 > 0:24:11so we're watching Hoy from a safe distance.
0:24:12 > 0:24:17Straight away, he starts dropping stones into the water.
0:24:17 > 0:24:19They are quite specific
0:24:19 > 0:24:20about what they use, actually,
0:24:20 > 0:24:22and how many stones.
0:24:22 > 0:24:24They don't put more stones in than they need.
0:24:24 > 0:24:29- He is checking the water rise every time he puts the stone in.- Yeah.
0:24:29 > 0:24:33He pops up and you can see the eye looking down. Look at that.
0:24:34 > 0:24:37- Look at that, the small stone wasn't going to be enough.- No.
0:24:39 > 0:24:41There we go, go on.
0:24:43 > 0:24:45No, can't quite reach.
0:24:45 > 0:24:47You know, Nikki, it is almost
0:24:47 > 0:24:51as if he understands the effect of dropping that stone in.
0:24:51 > 0:24:55That's right. He only does this when there is liquid in the tube.
0:24:55 > 0:24:58If there is a worm in the tube and it's filled with sand,
0:24:58 > 0:25:01he doesn't bother. He knows that it needs to be a liquid
0:25:01 > 0:25:04in that tube in order for the stones to work.
0:25:06 > 0:25:11Hoy understands that a sinking stone will cause the water level
0:25:11 > 0:25:16to rise, and this in turn will allow him to reach the wax worm.
0:25:16 > 0:25:20He also knows the same technique won't work with sand.
0:25:20 > 0:25:26And this reveals the first skill animals need to solve problems -
0:25:26 > 0:25:32the ability to understand the rules of cause and effect.
0:25:34 > 0:25:36But I am intrigued to know
0:25:36 > 0:25:40how Hoy worked all of this out in his mind.
0:25:41 > 0:25:45He was trained that, if he drops or knocks a stone
0:25:45 > 0:25:48into a tube, he gets a worm.
0:25:48 > 0:25:50But in the training apparatus, the worm comes out the bottom,
0:25:50 > 0:25:52not out the top, and there is no water.
0:25:52 > 0:25:57And having learned to associate stones with tubes to get food,
0:25:57 > 0:26:02what he has been able to do is then to transfer this to a novel problem,
0:26:02 > 0:26:03where there is water,
0:26:03 > 0:26:06where the worm comes out a totally different place.
0:26:06 > 0:26:09But he has been able to use his information flexibly
0:26:09 > 0:26:10and transfer it to novel problems.
0:26:10 > 0:26:13- He can join up his knowledge. - Exactly.
0:26:16 > 0:26:19So, Hoy was able to solve this problem,
0:26:19 > 0:26:23because he already knew how to use the stones.
0:26:23 > 0:26:26He is able to learn rules for one situation
0:26:26 > 0:26:30and then apply those rules to a new scenario.
0:26:33 > 0:26:37Scientists call this flexible thinking,
0:26:37 > 0:26:42and it is the second skill that animals need to solve problems.
0:26:42 > 0:26:48It is how the New Caledonian crow solved the multistage problem
0:26:48 > 0:26:54and also how Bran made such short work of my puzzle box.
0:26:56 > 0:26:59The birds were thinking flexibly,
0:26:59 > 0:27:03using previous experience to solve new problems.
0:27:05 > 0:27:10And it is an ability that seems sadly missing in my dogs.
0:27:10 > 0:27:14Lift the ball, please! Lift it! Lift it!
0:27:15 > 0:27:20Is that why Bran, the raven, so convincingly trounced my dogs?
0:27:20 > 0:27:22It's exactly that, yeah.
0:27:22 > 0:27:24So, the dogs can learn to do something,
0:27:24 > 0:27:28but what they can't do is to transfer it to a novel problem.
0:27:28 > 0:27:32Yes, I will be gracious in defeat on this account,
0:27:32 > 0:27:34given the quality of the opposition.
0:27:34 > 0:27:37I suspect, if you had been competing against a pigeon,
0:27:37 > 0:27:38you'd have been all right.
0:27:38 > 0:27:41They would've even that, that would've been fine.
0:27:48 > 0:27:51So, why are some animals better at solving problems than others?
0:27:53 > 0:27:56It is something we don't yet fully understand.
0:27:56 > 0:27:59But one thing that we do know is that the answer lies
0:27:59 > 0:28:01somewhere in here -
0:28:01 > 0:28:05the animal brain itself.
0:28:05 > 0:28:09Here are a couple of very interesting specimens.
0:28:09 > 0:28:13This one is the brain of a dog, in this case a terrier.
0:28:13 > 0:28:17And this one here is the brain of a crow.
0:28:17 > 0:28:21And it is immediately apparent that the dog's brain is about twice
0:28:21 > 0:28:23the size of that of the bird.
0:28:23 > 0:28:26So, we might imagine, simplistically, therefore,
0:28:26 > 0:28:29that the dog is a more intelligent animal.
0:28:29 > 0:28:32But we already know that the crow
0:28:32 > 0:28:35can solve problems that the dog can't.
0:28:35 > 0:28:37So, clearly, there is
0:28:37 > 0:28:41more to cleverness than just the size of the brain.
0:28:45 > 0:28:49To investigate what that could be, I have gathered together
0:28:49 > 0:28:52a range of preserved animal brains.
0:28:53 > 0:28:57If I arrange them in order of body size, a pattern emerges.
0:28:59 > 0:29:03The bigger the animal, the bigger the brain.
0:29:06 > 0:29:10It seems that the more body you have, the more brain cells
0:29:10 > 0:29:12you need to control it.
0:29:16 > 0:29:17In other words, there is
0:29:17 > 0:29:22a relationship between the mass of the body and the mass of the brain.
0:29:26 > 0:29:29And roughly speaking, it is a straight line.
0:29:31 > 0:29:35The dog lies pretty much bang on the line here, which is
0:29:35 > 0:29:38where you'd expect it, given its body size.
0:29:38 > 0:29:42And in fact, most animals lie very close to the line.
0:29:42 > 0:29:47But some sit above the line, like we humans.
0:29:47 > 0:29:51Our brains are very large for our body size.
0:29:51 > 0:29:54But what about the crow?
0:29:54 > 0:29:58The crow's brain is also above the line. It is up here,
0:29:58 > 0:30:01which means that its brain is bigger
0:30:01 > 0:30:04than we would expect just given its body size.
0:30:04 > 0:30:07In fact, it is about twice the size.
0:30:07 > 0:30:09Now, bizarre as it may seem,
0:30:09 > 0:30:12the dog's brain is physically twice the size of the crow's,
0:30:12 > 0:30:17but relative to its body size, the crow's brain is bigger than the dog.
0:30:17 > 0:30:23So, perhaps this extra mental power will allow the crow to
0:30:23 > 0:30:28think in a more complicated and more flexible way than the dog.
0:30:30 > 0:30:36And the crow isn't alone in having a brain twice as big as we'd expect.
0:30:36 > 0:30:40In fact, it is in the company of another animal
0:30:40 > 0:30:45known not only for its big brain but also its cleverness.
0:30:48 > 0:30:51It is our nearest relative - the chimpanzee.
0:30:54 > 0:30:58And the chimpanzee holds a special place in the history of science.
0:31:00 > 0:31:04In the 1960s, a young British scientist, Jane Goodall,
0:31:04 > 0:31:09observed chimps doing something that no-one thought animals capable of -
0:31:09 > 0:31:11using tools.
0:31:13 > 0:31:17I saw this dark shape hunched over a termite mound.
0:31:17 > 0:31:20He's making arm movements as though he's sliding it
0:31:20 > 0:31:23across the ground and obviously eating.
0:31:23 > 0:31:25But that was all I saw.
0:31:25 > 0:31:27And I went up to the heap and there were
0:31:27 > 0:31:31the pieces of grass lying there, termites moving about the surface.
0:31:31 > 0:31:34So I picked up one of these abandoned tools
0:31:34 > 0:31:37and pushed it into the mound, and the termites bit on.
0:31:37 > 0:31:39It was pretty obvious.
0:31:45 > 0:31:50Goodall had observed the chimps using blades of grass as tools
0:31:50 > 0:31:52to fish for termites.
0:31:53 > 0:31:57It was a discovery of immense significance,
0:31:57 > 0:32:00as her PhD supervisor immediately realised.
0:32:01 > 0:32:05And he sent his famous reply, "Now we have to redefine man,
0:32:05 > 0:32:09"redefine tool or accept chimpanzees as humans."
0:32:12 > 0:32:16Goodall's discovery shattered our ideas about what sets us
0:32:16 > 0:32:20apart from the rest of the animal kingdom.
0:32:20 > 0:32:22We had to accept that animals were cleverer
0:32:22 > 0:32:24than we'd given them credit for.
0:32:27 > 0:32:30It also gave researchers new insights into how
0:32:30 > 0:32:35our ancient ancestors might themselves have solved problems.
0:32:36 > 0:32:38And as we have discovered,
0:32:38 > 0:32:42chimps are not alone in being able to use tools.
0:32:42 > 0:32:45It is something that crows can do, too.
0:32:58 > 0:33:02To me, what is so important about using tools is that it reveals
0:33:02 > 0:33:07the next crucial ability that an animal needs to solve problems.
0:33:11 > 0:33:14For example, take this stick.
0:33:14 > 0:33:16If I want to use this as a tool,
0:33:16 > 0:33:19I need to be able to see it for more than what it is.
0:33:19 > 0:33:24More than just a piece of wood, what a piece of wood might be.
0:33:24 > 0:33:26What might it be?
0:33:26 > 0:33:30Well, I could sharpen one end and I could perhaps use it as a spear.
0:33:30 > 0:33:33Or I could set fire to it to generate some heat.
0:33:33 > 0:33:35When I'm going through these thought processes,
0:33:35 > 0:33:38there is no doubt that I am using flexible thinking,
0:33:38 > 0:33:41understanding the rules of cause-and-effect,
0:33:41 > 0:33:45but I am also using a type of thinking which is innovative.
0:33:45 > 0:33:49What I am using is imagination.
0:33:49 > 0:33:52I'm not just seeing the world as it is now,
0:33:52 > 0:33:56I am seeing the world how it could be.
0:33:56 > 0:34:00And this raises a very profound question.
0:34:00 > 0:34:04Could any other species of animal have an attribute
0:34:04 > 0:34:08so significantly human as imagination?
0:34:14 > 0:34:18To answer this question, I have come to Austria to meet a rather
0:34:18 > 0:34:20inquisitive and endearing type of bird.
0:34:22 > 0:34:26And this time it is not a member of the crow family.
0:34:26 > 0:34:30These are Goffins cockatoos, a type of parrot.
0:34:32 > 0:34:36Big-brained birds with a very curious nature.
0:34:40 > 0:34:42Can I have that back? Thank you.
0:34:44 > 0:34:47And I am here to meet Dr Alice Auersperg,
0:34:47 > 0:34:49an expert in these animals.
0:34:51 > 0:34:54She is studying their ability to innovate.
0:34:54 > 0:34:57And I am intrigued to know what that might reveal
0:34:57 > 0:35:00about their powers of imagination.
0:35:01 > 0:35:06- Alice, these birds are very keen to get to know me, it seems.- Yes.
0:35:06 > 0:35:09They are especially interested in you because you are new.
0:35:11 > 0:35:14And it is not just me that is new.
0:35:14 > 0:35:16So is the entire crew.
0:35:20 > 0:35:22And everything that we are wearing.
0:35:24 > 0:35:29My watch, in particular, has caught the attention of Olympia here.
0:35:29 > 0:35:31And within minutes,
0:35:31 > 0:35:33she has worked out how to release the clasp.
0:35:33 > 0:35:36When they find you, a human, inside the aviary,
0:35:36 > 0:35:40they look for everything that looks different on your body,
0:35:40 > 0:35:43like your shirt buttons or the shoe laces or your watch.
0:35:43 > 0:35:45They go specifically for that
0:35:45 > 0:35:48and they stay with it for a very long time.
0:35:48 > 0:35:51You like my shiny watch, don't you?
0:35:51 > 0:35:55Alice, I think I've had enough of being pecked and probed
0:35:55 > 0:35:57and pulled by your rather wonderful cockatoos.
0:35:57 > 0:36:00I'd like to see them in action now, mental action.
0:36:00 > 0:36:03Look, the watch is off again.
0:36:03 > 0:36:06Come on, I know you can steal my watch, but what more can you do?
0:36:08 > 0:36:12To investigate what is going on in the minds of these parrots,
0:36:12 > 0:36:17Alice created this - the lockbox.
0:36:17 > 0:36:19Trapped inside is a tasty nut,
0:36:19 > 0:36:23held securely behind this elaborate locking mechanism.
0:36:25 > 0:36:26To see how it opens,
0:36:26 > 0:36:31we need to employ the services of a master safe-cracker.
0:36:31 > 0:36:34Or Muppet, as he is perhaps inappropriately called.
0:36:34 > 0:36:39Before we begin, though, there is the question of eyewear.
0:36:40 > 0:36:43If you want to start, we have to put sunglasses on
0:36:43 > 0:36:46because we could cue the birds with our eye movements.
0:36:46 > 0:36:49Can they see where we are looking? Do they have the ability to do that?
0:36:49 > 0:36:51We don't know whether this species can,
0:36:51 > 0:36:55but it has been proven that some can follow the eye movement of humans.
0:36:55 > 0:36:57Better safe than sorry.
0:36:57 > 0:37:01We'll forgive fashion for that and make scientific progress.
0:37:01 > 0:37:04And here comes Muppet. He's out.
0:37:07 > 0:37:09- Oh, he is displaying towards you. - A little bit of display.
0:37:09 > 0:37:11Yes, he's a boy now.
0:37:13 > 0:37:15Very nice, yes. That is a crest of some distinction.
0:37:15 > 0:37:18I had one like that in the 1980s myself.
0:37:18 > 0:37:21But perhaps, Muppet, you could take your attention to the lock?
0:37:23 > 0:37:26Muppet has done this before,
0:37:26 > 0:37:30and he delivers...a masterclass.
0:37:30 > 0:37:34He quickly removes the pin and then the screw.
0:37:40 > 0:37:44He discards the central bolt before shifting the locking wheel.
0:37:48 > 0:37:51And this releases the final bolt.
0:37:51 > 0:37:52Voila!
0:37:52 > 0:37:54He has reached the nut inside.
0:37:59 > 0:38:02Wow. I should have timed it, shouldn't I?
0:38:04 > 0:38:08But to make sure that Muppet can't learn the sequence by heart,
0:38:08 > 0:38:13Alice can swap the lock sections around or even remove them entirely.
0:38:13 > 0:38:18So now I want to change the way in which the box works
0:38:18 > 0:38:24and set Muppet a new challenge, one that he has never seen before.
0:38:25 > 0:38:28There are five parts. Why don't we take out the middle bit?
0:38:28 > 0:38:31- Take out the bolt.- Yes, let's.
0:38:31 > 0:38:34The upper section is now redundant,
0:38:34 > 0:38:38leaving only the lower parts in operation.
0:38:38 > 0:38:41It may look like we have made it easier, but in fact,
0:38:41 > 0:38:46we have created an entirely new problem with a different solution.
0:38:46 > 0:38:51If Muppet can't see this, he will just repeat what he did before,
0:38:51 > 0:38:54and robotically go for the pin at the top.
0:38:54 > 0:38:57But if he can see the new problem
0:38:57 > 0:39:00and imagine a new solution,
0:39:00 > 0:39:03then he will go straight for the wheel.
0:39:03 > 0:39:07OK, Alice, let's... let's give him a go.
0:39:07 > 0:39:10So now, the moment of truth.
0:39:15 > 0:39:18He has gone straight for the wheel.
0:39:21 > 0:39:23And then the bar.
0:39:25 > 0:39:28And he's in in less than ten seconds.
0:39:30 > 0:39:34Muppet got it right first time.
0:39:34 > 0:39:38And that gives us a crucial insight into his mind.
0:39:38 > 0:39:44He must have looked at the problem, worked it out in his head
0:39:44 > 0:39:48and imagined the solution.
0:39:49 > 0:39:52That was a hard-earned nut.
0:39:58 > 0:40:05So imagination is the third ability that animals need to solve problems.
0:40:05 > 0:40:08It's a skill that seems to allow them to work out
0:40:08 > 0:40:13new solutions in their heads before putting them into practice.
0:40:20 > 0:40:24Up until now, all of the animals that we've looked at
0:40:24 > 0:40:26have used their imagination to solve problems
0:40:26 > 0:40:29which are sat right in front of them
0:40:29 > 0:40:31but we humans can do so much more than that.
0:40:31 > 0:40:35We use our imagination to project into the future,
0:40:35 > 0:40:37to see problems coming
0:40:37 > 0:40:40and think about how we are going to solve them.
0:40:40 > 0:40:45Until now, we've always thought of that as a purely human attribute
0:40:45 > 0:40:49but what I want to know is can these clever animals do that too?
0:40:54 > 0:40:56There is a common behaviour in the animal world
0:40:56 > 0:40:59that seems to be about planning for the future.
0:40:59 > 0:41:02It's called caching.
0:41:02 > 0:41:04It's what squirrels do in the autumn,
0:41:04 > 0:41:07hiding nuts in the ground so they can be dug up
0:41:07 > 0:41:09and eaten over the winter months.
0:41:15 > 0:41:18But if caching were an Olympic sport
0:41:18 > 0:41:21then the corvids would be the gold medallists.
0:41:21 > 0:41:26Most of them seem to do it, much to the annoyance of the squirrels.
0:41:34 > 0:41:37And this American corvid, the Clark's nutcracker,
0:41:37 > 0:41:39is the caching king.
0:41:40 > 0:41:44Researchers have observed how every year it can store
0:41:44 > 0:41:49and remember the location of thousands of different seeds.
0:41:53 > 0:41:56This bird truly is the master of memory.
0:42:05 > 0:42:07But is this just another example
0:42:07 > 0:42:10of instinctive behaviour to survive the winter?
0:42:10 > 0:42:15Or is there something far more complex going on?
0:42:15 > 0:42:19It's a question that's greatly intrigued Professor Nicky Clayton.
0:42:21 > 0:42:23She studies Western scrub-jays,
0:42:23 > 0:42:28another American corvid renowned for its caching behaviour.
0:42:28 > 0:42:32Nicky wanted to discover whether they could do more
0:42:32 > 0:42:36than just remember where they buried food in the past.
0:42:37 > 0:42:42If they can travel back in their mind's eye to think about the past,
0:42:42 > 0:42:46can they also travel forward in the mind's eye to think about the future?
0:42:46 > 0:42:50Can they imagine the future, if you like? Can they plan ahead?
0:42:55 > 0:42:57To find out, Nicky created an experiment
0:42:57 > 0:43:00based on a very human annoyance -
0:43:00 > 0:43:04waking up to find that breakfast is off the menu.
0:43:05 > 0:43:08For six days, the birds were housed in this aviary,
0:43:08 > 0:43:11split into three zones.
0:43:11 > 0:43:14In the middle is the dining room,
0:43:14 > 0:43:16where the birds were fed during the day,
0:43:16 > 0:43:21and at either end are the bedrooms, where they were kept at night.
0:43:21 > 0:43:23But there is a twist.
0:43:23 > 0:43:26Kept overnight in this bedroom,
0:43:26 > 0:43:29the birds were served an early breakfast
0:43:29 > 0:43:32but kept overnight in this one,
0:43:32 > 0:43:36they got no breakfast and went hungry until mid-morning.
0:43:39 > 0:43:43The birds experienced this daily routine for almost a week.
0:43:45 > 0:43:49We give them three experiences of waking up in the hungry room
0:43:49 > 0:43:53and three experiences of waking up in the room that serves breakfast.
0:43:53 > 0:43:56But the important point is the birds themselves
0:43:56 > 0:43:59didn't know which room they would end up in on any given day.
0:44:03 > 0:44:06But then Nicky changed the test.
0:44:06 > 0:44:11She allowed the birds to cache food in the evening before bedtime.
0:44:13 > 0:44:18She placed caching trays in both the hungry and breakfast rooms.
0:44:18 > 0:44:21The question was where would they choose to store the food?
0:44:23 > 0:44:27Nicky wanted to know if the birds could use their past experience
0:44:27 > 0:44:32of the two different rooms and plan for the future,
0:44:32 > 0:44:34namely for breakfast time tomorrow.
0:44:36 > 0:44:38The results left no doubt.
0:44:41 > 0:44:44What we found is that the birds cache about five times
0:44:44 > 0:44:49as much in the hungry room as they cache in the breakfast room.
0:44:50 > 0:44:53They can imagine what they are going to need the following morning when
0:44:53 > 0:44:58they wake up hungry so they can solve a problem before it's even happened.
0:44:59 > 0:45:04So what this experiment shows is that the birds can plan for the future.
0:45:04 > 0:45:09So the jays' caching behaviour is far more than mere instinct.
0:45:09 > 0:45:12They have a grasp of the past,
0:45:12 > 0:45:17but can also anticipate future needs and, crucially, plan for it.
0:45:17 > 0:45:21This skill is very rare in the animal kingdom
0:45:21 > 0:45:26and it's the fourth key ability needed to solve problems.
0:45:26 > 0:45:28It's called mental time travel.
0:45:30 > 0:45:32It's the ability to go backwards
0:45:32 > 0:45:36and forwards in the mind's eye, so it's about projecting yourself
0:45:36 > 0:45:41in time to remember the past and to imagine the future.
0:45:46 > 0:45:50In humans, mental time travel is a skill that takes a while to develop.
0:45:52 > 0:45:54We're not born with it.
0:45:54 > 0:45:59These children are about to undergo the sweetie challenge.
0:45:59 > 0:46:01The task is simple.
0:46:01 > 0:46:03Each child is given a sweet.
0:46:03 > 0:46:06They are told that, if they leave it uneaten,
0:46:06 > 0:46:09they will get a second one 15 minutes later.
0:46:10 > 0:46:16The question is, can they plan for a future in which they have two sweets
0:46:16 > 0:46:21or will the lure of instant gratification be too much?
0:46:21 > 0:46:25It's a skill that children acquire as they get older.
0:46:27 > 0:46:31I think this kind of cognitive capacity is highly sophisticated.
0:46:31 > 0:46:34We know that young children don't start developing
0:46:34 > 0:46:38these kind of skills until they are at least four years of age.
0:46:40 > 0:46:43Clearly, if you are a bird or a human,
0:46:43 > 0:46:46it's no bad thing to be a mental time traveller.
0:46:54 > 0:46:56When we look at the world's cleverest creatures,
0:46:56 > 0:47:00we see a group of very different animals -
0:47:00 > 0:47:03the great apes, the corvids, the parrots.
0:47:03 > 0:47:06And yet, they all think a little bit like we do.
0:47:07 > 0:47:11They have the ability to understand cause and effect
0:47:11 > 0:47:16and can utilise this understanding in new and novel situations.
0:47:16 > 0:47:21They can also implement imagination and this allows them
0:47:21 > 0:47:24to think ahead, to plan in the future.
0:47:24 > 0:47:28Now, together, these abilities allow them
0:47:28 > 0:47:33something which is incredibly rare in the animal world.
0:47:33 > 0:47:37It's the power to reason, the power to solve problems.
0:47:38 > 0:47:41But of course, it also raises another question -
0:47:41 > 0:47:44what is so special about this group of animals?
0:47:44 > 0:47:47What could they possibly have in common?
0:47:52 > 0:47:56To answer that, I want to look in a very different environment.
0:48:04 > 0:48:07'Here on the island of Bimini in the Bahamas,
0:48:07 > 0:48:09'I'm seeking out an elusive creature.'
0:48:12 > 0:48:16It's a creature that's as different from a bird or a chimp
0:48:16 > 0:48:19as it's possible to be.
0:48:21 > 0:48:25Now, this beautiful animal is a common octopus.
0:48:25 > 0:48:28Don't worry too much about it being out of water.
0:48:28 > 0:48:32They will frequently move over land, between rock pools like these,
0:48:32 > 0:48:34so he will be OK for a while.
0:48:34 > 0:48:38It lives in a world which is very alien to us -
0:48:38 > 0:48:41rock pools and rocky caverns on the coast here.
0:48:41 > 0:48:44And as a consequence, its anatomy is very different.
0:48:44 > 0:48:47Inside this animal, there are three hearts
0:48:47 > 0:48:50but perhaps the most profound difference of all is its brain.
0:48:58 > 0:49:00The octopus brain is spread around the body.
0:49:05 > 0:49:09Each leg even has its own mini brain to control it.
0:49:10 > 0:49:13It's nothing like the one-stop shop that we have.
0:49:15 > 0:49:19But what's extraordinary is this animal has problem-solving abilities
0:49:19 > 0:49:22similar to those of the great apes...
0:49:24 > 0:49:27..the parrots and the crows.
0:49:31 > 0:49:35This is a veined octopus just off the coast of Indonesia.
0:49:35 > 0:49:39In this environment, it is very exposed to predators
0:49:39 > 0:49:41but it has worked out a solution.
0:49:44 > 0:49:47It's found a discarded coconut shell
0:49:47 > 0:49:50and despite being an unfamiliar object,
0:49:50 > 0:49:52the octopus sees its potential.
0:49:52 > 0:49:58It tries it on for size before picking it up and carrying it away.
0:49:58 > 0:50:02Now, when a threat appears, it has a place to hide
0:50:02 > 0:50:05and it can retreat inside its coconut sanctuary.
0:50:06 > 0:50:10This is an example of an octopus using tools.
0:50:11 > 0:50:15It seems to be using all the key abilities we've seen
0:50:15 > 0:50:19in the cleverest animals on land.
0:50:19 > 0:50:23So what can the octopus, with its strange brain,
0:50:23 > 0:50:27possibly have in common with apes and birds?
0:50:27 > 0:50:29When animals are very different,
0:50:29 > 0:50:33then the similarities can actually be a lot easier to see
0:50:33 > 0:50:37and we have to look beyond the fact that birds can fly,
0:50:37 > 0:50:40apes have dextrous hands
0:50:40 > 0:50:43or that octopus actually move on their eight arms.
0:50:43 > 0:50:44We have to not concentrate so much
0:50:44 > 0:50:47on the physical nature of these animals,
0:50:47 > 0:50:50but look at the things that have made them what they are.
0:50:50 > 0:50:53And when we do that, a pattern emerges.
0:50:57 > 0:51:02For instance, all these animals eat a wide variety of foods
0:51:02 > 0:51:05and need to master different techniques in order to obtain them.
0:51:07 > 0:51:12They crack, they pluck and they hunt.
0:51:14 > 0:51:16Our own omnivorous diet isn't too different.
0:51:19 > 0:51:23And all these animals tend to be both predator and prey.
0:51:26 > 0:51:30Which is also true of our own ancient ancestors
0:51:30 > 0:51:33on the plains of Africa, millions of years ago.
0:51:33 > 0:51:36So it seems that, to live flexibly,
0:51:36 > 0:51:39you have to be able to think flexibly.
0:51:40 > 0:51:44But there is something else that the supreme problem solvers -
0:51:44 > 0:51:47the apes, the corvids and the parrots - share.
0:51:48 > 0:51:52They live in groups.
0:51:53 > 0:51:55So whether they walk, swim or fly,
0:51:55 > 0:51:58the supreme problem solvers of the animal kingdom are not
0:51:58 > 0:52:02so different from one another as we might have first imagined
0:52:02 > 0:52:05and, although their minds are not as potent as ours,
0:52:05 > 0:52:07their powers to reason
0:52:07 > 0:52:11and even exercise imagination are quite remarkable.
0:52:11 > 0:52:16But then, up until now, we have been looking at them as individuals.
0:52:16 > 0:52:20What I want to understand next is do they have the capacity,
0:52:20 > 0:52:24like humans, to actually share the solutions to problems?
0:52:24 > 0:52:28In short, if they come up with a good idea, can they pass it on?
0:52:40 > 0:52:44On New Caledonia, the crows have lots of good ideas.
0:52:47 > 0:52:49They are precision tool makers.
0:52:51 > 0:52:54This one is in the process of doing something
0:52:54 > 0:52:58we would normally expect only of humans.
0:52:58 > 0:53:02It's crafting a hook that it's going to use to catch its prey.
0:53:03 > 0:53:06It's an astounding behaviour.
0:53:11 > 0:53:14Dr Alex Taylor and his colleagues are now investigating whether
0:53:14 > 0:53:19these birds are able to share their tool-making skills with each other.
0:53:21 > 0:53:23That is amazing.
0:53:23 > 0:53:26So they have sculpted a little hook out of another piece
0:53:26 > 0:53:28of the twig that formerly would have run out here.
0:53:28 > 0:53:33It's beautiful. It's almost like a primitive human tool, isn't it?
0:53:33 > 0:53:35It does appear that way.
0:53:35 > 0:53:38We talk about the imposition of three-dimensional form
0:53:38 > 0:53:40onto a natural object.
0:53:40 > 0:53:43That's something that humans have only been able to do
0:53:43 > 0:53:45for the last 100,000 or 200,000 years
0:53:45 > 0:53:48and here we have a crow doing something very similar.
0:53:48 > 0:53:51And you can see how that can be useful because a crow would be able
0:53:51 > 0:53:54to insert that into a hole and quite literally use that hook
0:53:54 > 0:53:57to draw out a grub or anything else it was after.
0:53:57 > 0:53:59Absolutely.
0:53:59 > 0:54:03Made by a bird! That is absolutely brilliant! Absolutely brilliant!
0:54:06 > 0:54:09And of even more interest to Alex are these -
0:54:09 > 0:54:13intricately cut tools from the leaves of the pandanus tree.
0:54:15 > 0:54:17Unlike the hooks,
0:54:17 > 0:54:20there are distantly different types of pandanus tool.
0:54:20 > 0:54:23They differ in complexity,
0:54:23 > 0:54:28ranging from a simple leaf fragment to multistep implements like these.
0:54:29 > 0:54:31And across the island,
0:54:31 > 0:54:35different groups of crows use different types of these tools.
0:54:38 > 0:54:42In the south, many different fragments are found
0:54:42 > 0:54:44that, as we move north,
0:54:44 > 0:54:49the crows start to favour more complex, multi-staged tools.
0:54:50 > 0:54:53It means the different groups of crows
0:54:53 > 0:54:55have their own ways of doing things.
0:54:57 > 0:55:00In human society, we would call this culture.
0:55:03 > 0:55:06What we are seeing across New Caledonia is populations
0:55:06 > 0:55:08of crows that appear to have traditions
0:55:08 > 0:55:11of making single-step tools or two-step or three-step tools
0:55:11 > 0:55:14and these traditions are persisting over 10 or 15 years at least,
0:55:14 > 0:55:17that's as much...how long we've been studying them for
0:55:17 > 0:55:19and we believe they have been there for a lot longer.
0:55:19 > 0:55:22It appears there's some kind of transmission of tool design
0:55:22 > 0:55:25across the population.
0:55:26 > 0:55:29A rare and fascinating glimpse of how this might happen
0:55:29 > 0:55:31has been captured on camera.
0:55:31 > 0:55:36Here an adult bird is using a stick to probe for grubs inside a log.
0:55:40 > 0:55:43A youngster stands by, watching,
0:55:43 > 0:55:47as the adult seems to demonstrate the right way to use the tool.
0:55:50 > 0:55:52And when the adult departs,
0:55:52 > 0:55:55she leaves behind the stick in the hole.
0:55:55 > 0:55:59The youngster can now have a go itself.
0:55:59 > 0:56:01Although this one has some way to go
0:56:01 > 0:56:04before it becomes an expert like its parents.
0:56:05 > 0:56:10It seems as though one way ideas can travel through the crow population
0:56:10 > 0:56:13is via family groups, the social circle.
0:56:15 > 0:56:19But Alex's research suggests something even more extraordinary -
0:56:19 > 0:56:24that, with each new generation, the ideas don't stand still
0:56:24 > 0:56:26but are honed and improved.
0:56:30 > 0:56:33When we talk about this, we talk about the ratchet effect,
0:56:33 > 0:56:36which is this idea that it's a really good idea
0:56:36 > 0:56:39to be able to copy each other and, as a group, you can end up
0:56:39 > 0:56:42being able to build better and better tools.
0:56:42 > 0:56:45Obviously, we don't invent the wheel every generation ourselves,
0:56:45 > 0:56:47we make it better and better.
0:56:47 > 0:56:50Potentially, this is what's going on here with the crows.
0:56:50 > 0:56:52There's no concrete evidence that any animal species
0:56:52 > 0:56:55is able to actually show this ratcheting up of their technology,
0:56:55 > 0:56:57to make it more and more sophisticated.
0:56:57 > 0:56:59So it would just be crows and humans?
0:56:59 > 0:57:02- No chimpanzees? Nothing? - At the moment, no.
0:57:02 > 0:57:04It's something we think is unique to humans,
0:57:04 > 0:57:06but maybe is going on with these crows as well.
0:57:10 > 0:57:16The New Caledonian crow has only been studied since the early 1990s.
0:57:17 > 0:57:21In that short period, scientists have revealed an animal mind
0:57:21 > 0:57:24that rivals the problem-solving skills of our closest cousin,
0:57:24 > 0:57:26the chimpanzee.
0:57:28 > 0:57:32And for me, the really exciting thing
0:57:32 > 0:57:36is that we are just beginning to understand these animals.
0:57:36 > 0:57:39Who knows what else they might be capable of?
0:57:41 > 0:57:44On this journey, I've come to an understanding
0:57:44 > 0:57:47about what makes some animals cleverer than others
0:57:47 > 0:57:50and even where that cleverness actually comes from.
0:57:52 > 0:57:56And whilst we might reign supreme across the animal kingdom
0:57:56 > 0:57:59when it comes to complex thought, we are certainly not alone.
0:57:59 > 0:58:02It also seems we may not hold a monopoly
0:58:02 > 0:58:06on the ability to share ideas and learn from one another.
0:58:06 > 0:58:09So perhaps it's no surprise at all
0:58:09 > 0:58:13that the most intelligent animals on our planet are the social ones.
0:58:16 > 0:58:18And next time I'll be investigating
0:58:18 > 0:58:21the minds of some very social animals.
0:58:21 > 0:58:25I'll uncover the secrets of dolphin society,
0:58:25 > 0:58:29discover how chimps deceive one another
0:58:29 > 0:58:32and learn that we are not alone in mourning our dead.