0:00:02 > 0:00:04BOTH: We are Dr Chris and Dr Xand van Tulleken.
0:00:04 > 0:00:06And we're tracking down the most awesome...
0:00:06 > 0:00:07..incredible...
0:00:07 > 0:00:11BOTH: ..and epic things in the universe!
0:00:21 > 0:00:24BOTH: Come with us and discover unbelievable things
0:00:24 > 0:00:27that will Blow Your Mind!
0:00:29 > 0:00:33Blow Your Mind will be bringing you all the top experts on the planet.
0:00:33 > 0:00:37From icebergs to elephants, spaceships to sharks.
0:00:37 > 0:00:41And, this week, it's all about amazing animals.
0:00:41 > 0:00:44So, hold on to your brains, here's what's coming up.
0:00:44 > 0:00:48This time, we'll be looking at one of the cleverest animals of all -
0:00:48 > 0:00:50the dolphin.
0:00:50 > 0:00:53We'll see some dolphins that like to hold hands.
0:00:53 > 0:00:56Others that think they're pretty good looking.
0:00:56 > 0:00:57And, amazingly,
0:00:57 > 0:01:01we'll meet a dolphin that can see without using it's eyes.
0:01:01 > 0:01:04I'm going to tell you a joke in dolphin language.
0:01:04 > 0:01:06Ready?
0:01:06 > 0:01:10DOLPHIN-LIKE SOUNDS
0:01:11 > 0:01:12What is that?
0:01:12 > 0:01:16The joke in English is, what do you call a fish with no eyes?
0:01:16 > 0:01:19- I don't know.- A fsh.- That was terrible. But, this isn't.
0:01:19 > 0:01:23- We're about to meet a dolphin with no eyes.- What, a dolphn?
0:01:23 > 0:01:26No, actually this dolphin's just had his eyes covered up.
0:01:26 > 0:01:30It's an experiment they do at the Dolphin Research Centre in Florida.
0:01:30 > 0:01:33Chris Packham went to find out more.
0:01:33 > 0:01:37I've come to the Dolphin Research Centre in Florida to see
0:01:37 > 0:01:40something that dolphins can do with their sense of hearing.
0:01:41 > 0:01:44Now, it's hard to study dolphins in the open ocean,
0:01:44 > 0:01:47but keeping them in captivity is controversial.
0:01:47 > 0:01:49And, since 1988,
0:01:49 > 0:01:54aquariums in the United States don't take dolphins from the wild.
0:01:54 > 0:01:57Dolphins like Tanner were born in captivity.
0:01:58 > 0:01:59Tanner, are you ready?
0:01:59 > 0:02:01No? Yes, you are ready.
0:02:01 > 0:02:04Researchers Armando and Wade want to show me
0:02:04 > 0:02:09an ingenious experiment to demonstrate how Tanner uses sound.
0:02:09 > 0:02:12I have a list of the behaviours right here, now, I can't see them.
0:02:12 > 0:02:15Please don't show them to me but you are going to point out...
0:02:15 > 0:02:16'I'm going to select an action from
0:02:16 > 0:02:19'a list for Wade to perform in the water.'
0:02:19 > 0:02:21Wade, go head in.
0:02:21 > 0:02:23I'm only showing Wade.
0:02:23 > 0:02:27Armando and Tanner have no idea which one he's about to do.
0:02:27 > 0:02:32- OK, Wade, let's go for this one, please. OK?- Tanner, imitate.
0:02:32 > 0:02:37With his eyes covered, Tanner will now attempt to imitate Wade.
0:02:37 > 0:02:39Then the other one will go on the left eye,
0:02:39 > 0:02:42but I have to give him the signal first, which means imitate.
0:02:42 > 0:02:44Are you ready? Imitate.
0:02:45 > 0:02:49So, will Tanner know what Wade is doing?
0:02:52 > 0:02:58There he goes, Wade is upside down and Tanner is upside down as well.
0:02:58 > 0:03:02- Upside down, in the water.- That's one out of one.- Good, good.
0:03:02 > 0:03:06'OK, that's one out of one, but for something this bizarre,
0:03:06 > 0:03:07I need a little more proof.'
0:03:07 > 0:03:09- Shall we try another? - Try another one?
0:03:09 > 0:03:12- Let me put the eye cup on. - Let's go for this one then, Wade.
0:03:17 > 0:03:20'Tanner appears to take a moment to listen before
0:03:20 > 0:03:23imitating Wade's exact movements.'
0:03:23 > 0:03:25Pretty impressive, I have to say.
0:03:26 > 0:03:29'And for the piece de resistance, the bob.'
0:03:33 > 0:03:37- Now, watch. He's reading.- Yeah, he's reading, without a shred of a doubt.
0:03:37 > 0:03:40He's reading without seeing. There's no question of that.
0:03:40 > 0:03:42And getting it right.
0:03:42 > 0:03:45- Good boy, Tanner.- Wade, thank you very much, thank you.- Excellent.
0:03:45 > 0:03:47Tanner, you are the best.
0:03:47 > 0:03:51Wow, so it's as if Tanner the dolphin can sense what Wade's
0:03:51 > 0:03:54movements are without seeing them. How is he doing that?
0:03:54 > 0:03:58Well, scientists believe that he's using sound in an amazing way.
0:03:58 > 0:04:00It's called echolocation.
0:04:00 > 0:04:02And this is how dolphins do it.
0:04:06 > 0:04:07It's all because of this.
0:04:09 > 0:04:11A specialised, fat filled organ called
0:04:11 > 0:04:15the melon, behind their forehead, gives off sound waves.
0:04:17 > 0:04:21But the key to echolocation is the dolphin listening to the
0:04:21 > 0:04:23echoes of those sound waves as they come back.
0:04:25 > 0:04:29Dolphins pick up sound waves in a special cavity in their jaw
0:04:29 > 0:04:32that amplifies them before sending them to their inner ears.
0:04:36 > 0:04:40They use echolocation to hunt down and pinpoint prey.
0:04:42 > 0:04:43Even in darkness.
0:04:45 > 0:04:46That's amazing.
0:04:46 > 0:04:49So, Tanner is making clicks and then listening to the
0:04:49 > 0:04:52reflection of that sound off Wade's body, the echo.
0:04:52 > 0:04:56And he can then use that echo to work out the movements that
0:04:56 > 0:05:00Wade is making. It's as if he's seeing with his hearing.
0:05:00 > 0:05:01That's right, that's right.
0:05:01 > 0:05:04Now, you might think that echolocation is something that
0:05:04 > 0:05:08only dolphins can do but, in fact, you can do it a tiny bit as well.
0:05:08 > 0:05:11If you imagine standing in a room and shouting, you could tell
0:05:11 > 0:05:14whether that room was a big room like a sports hall or a small
0:05:14 > 0:05:17room like your bedroom just from listening to the echo.
0:05:17 > 0:05:20And in fact, some people with visual problems have learned to make
0:05:20 > 0:05:22clicks, a bit like a dolphin, and they can use
0:05:22 > 0:05:26the reflection of that sound to find objects in the world near to them.
0:05:26 > 0:05:29But that isn't the only thing that's amazing about dolphins.
0:05:29 > 0:05:32Check out how they behave with their friends.
0:05:34 > 0:05:37Now, everyone knows that dolphins have amazing abilities
0:05:37 > 0:05:39but just how intelligent are they?
0:05:40 > 0:05:44In order to find out, Chris and the local researchers want to see how
0:05:44 > 0:05:46they act in their social group,
0:05:46 > 0:05:48sort of like how you would act with your friends at school.
0:05:50 > 0:05:53And, today, Chris gets to live out a childhood dream.
0:05:53 > 0:05:56Swimming with wild dolphins for the very first time.
0:05:58 > 0:06:00Look at the conditions, the suns shining, the sea is blue
0:06:00 > 0:06:05and these stunning animals are just about 10m behind me,
0:06:05 > 0:06:07I'm itching to get in, itching.
0:06:18 > 0:06:22We're lucky and we are quickly surrounded by a pod of 16
0:06:22 > 0:06:24dolphins from the Bimini group.
0:06:24 > 0:06:29And the dolphins swarm around, creating bubbles with their tails.
0:06:31 > 0:06:33But then they do something strange.
0:06:36 > 0:06:40They start to use their beaks to push each other through the water.
0:06:46 > 0:06:49When you look at their behaviour from different angles,
0:06:49 > 0:06:53a surprising story of complex social relationships emerges.
0:06:55 > 0:06:59What appeared to be a random ball of eight dolphins actually
0:06:59 > 0:07:01contains three friends.
0:07:10 > 0:07:14Dolphins create a strong bond between each other by touching
0:07:14 > 0:07:18each others pectoral fins, sort of like holding hands.
0:07:18 > 0:07:20Billy and Tim are best friends.
0:07:20 > 0:07:23The researchers have tracked them for a long time and they know
0:07:23 > 0:07:28that both are 13, best mates and the main members of this dolphin group.
0:07:29 > 0:07:32Here, they're doing that strange pushing behaviour again.
0:07:34 > 0:07:37A young male presents his belly to five others.
0:07:37 > 0:07:39We know that one of these is
0:07:39 > 0:07:41a seven-year-old male who's
0:07:41 > 0:07:43called number 95.
0:07:43 > 0:07:46Together, they use their beaks to push the other dolphin
0:07:46 > 0:07:48through the water.
0:07:48 > 0:07:51They repeat this behaviour half a dozen times.
0:07:51 > 0:07:54Here, Speedy the dolphin is involved in the pushing.
0:07:55 > 0:07:58Why the dolphins do this is a mystery.
0:07:58 > 0:08:01The researchers think it might be that the dolphins are actually
0:08:01 > 0:08:04playing with each other, it's a bit like a ritual to welcome new
0:08:04 > 0:08:05dolphins into the group.
0:08:08 > 0:08:10So dolphins are lot like human beings.
0:08:10 > 0:08:13They have friends, they like to hold hands,
0:08:13 > 0:08:15- they even like to play and muck around.- Yeah, and that's not all.
0:08:15 > 0:08:18What they do when they want a snack with blow your mind!
0:08:23 > 0:08:26In these shallow waters, further down the coast of Florida,
0:08:26 > 0:08:31individual dolphins find it hard to catch the fast moving fish.
0:08:33 > 0:08:36But watch what happens when they act as a group.
0:08:38 > 0:08:41One dolphin swims in a circle,
0:08:42 > 0:08:47it whips up a wall of muddy water the corrals any fish inside.
0:08:50 > 0:08:53Three wait, anticipating what the other is doing.
0:08:56 > 0:08:59The fish are driven right into their mouths.
0:08:59 > 0:09:04They've cleverly worked out an efficient way to catch fish.
0:09:09 > 0:09:11This is extraordinary group behaviour.
0:09:11 > 0:09:12So that's amazing.
0:09:12 > 0:09:15Basically what the dolphins are doing is taking it in turns,
0:09:15 > 0:09:17wiggling their fins and scaring the fish
0:09:17 > 0:09:20so much that the fish actually jump into the other dolphins mouths.
0:09:20 > 0:09:22Yeah, it's absolutely extraordinary, isn't it?
0:09:22 > 0:09:25It's almost as if they've had a conversation beforehand
0:09:25 > 0:09:27to, like, discuss what they're going to do.
0:09:27 > 0:09:28Yeah, like one of the dolphins goes,
0:09:28 > 0:09:31"Right, lads, we're going to get together, you're going to go
0:09:31 > 0:09:32"there, I'm going to wheel my fins
0:09:32 > 0:09:34"and then we're going to get the fish. Right?"
0:09:34 > 0:09:37Right. The dolphin from east London, in Florida.
0:09:37 > 0:09:39- Well, he might be on holiday.- Mm.
0:09:39 > 0:09:42OK, well, let's find out more about how the dolphins work in groups.
0:09:42 > 0:09:45I've come to the National Aquarium in Baltimore.
0:09:47 > 0:09:51Aquariums in the United States don't take any dolphins from the wild,
0:09:51 > 0:09:54except for the occasional stranding.
0:09:55 > 0:09:59The head trainer, Allison Ginsberg, is introducing me to Nonny.
0:10:01 > 0:10:05Each of the animals may know up to 65-70 different hand gestures that
0:10:05 > 0:10:08correlate to different behaviours that we would like them to perform.
0:10:08 > 0:10:11So you offer them the gesture and they produce the behaviour.
0:10:11 > 0:10:13Correct, so take your fingers like this
0:10:13 > 0:10:15and you're just going to wiggle them.
0:10:15 > 0:10:18DOLPHIN WHISTLES
0:10:18 > 0:10:22Very nice. We'll do one more, take your hands like this
0:10:22 > 0:10:24- and you're going to wave them at her.- OK.
0:10:28 > 0:10:30- Very nice.- What about that.
0:10:30 > 0:10:34- And she knows up to 70 gestures? - Mm-hmm.- Amazing.
0:10:34 > 0:10:36Wow, so those dolphins are pretty smart.
0:10:36 > 0:10:39They can recognise signals and commands, which must be pretty
0:10:39 > 0:10:42useful if you're swimming in a pod with other dolphins.
0:10:42 > 0:10:47Well, yeah, it is, but, each dolphin also needs some individuality
0:10:47 > 0:10:50so that they know what they're meant to be doing in the pod.
0:10:50 > 0:10:53So, do you think each dolphin can tell itself from the other dolphins?
0:10:53 > 0:10:56Well, that is a really interesting question.
0:10:56 > 0:11:00Chris Packham went to find out by hiding in a secret chamber
0:11:00 > 0:11:02so he could spy on the dolphins.
0:11:02 > 0:11:06This is the observation chamber here at the aquarium.
0:11:06 > 0:11:10It's cramped, but we're going to get some fantastic views.
0:11:14 > 0:11:16Now he's going down to the bottom
0:11:16 > 0:11:18but the other one turns around and comes right back.
0:11:20 > 0:11:22- The beautiful bubble ring.- Wow.
0:11:24 > 0:11:27These dolphins have learned to make their own bubble rings.
0:11:29 > 0:11:31It's a clever enough trick,
0:11:31 > 0:11:34but Diana wants to investigate something far more fundamental.
0:11:36 > 0:11:40Do dolphins recognise themselves as individuals?
0:11:41 > 0:11:46Diana places a one-way mirror inside the observation window to
0:11:46 > 0:11:47test the dolphins.
0:11:51 > 0:11:53So now we're looking through a window
0:11:53 > 0:11:55and they'll be seeing the mirror.
0:11:56 > 0:11:58They aren't looking at us, that's the key thing.
0:11:58 > 0:12:02- They're looking at themselves. - They're looking at themselves.
0:12:02 > 0:12:03Wow, look at that.
0:12:05 > 0:12:08Look at him twisting his body to look at himself.
0:12:11 > 0:12:14He's loving himself. That's one vain dolphin you've got there.
0:12:20 > 0:12:26Dolphins don't behave like this if they simply meet another dolphin.
0:12:26 > 0:12:30This suggests that they understand that what they're seeing
0:12:30 > 0:12:34isn't another animal but a reflection of themselves.
0:12:36 > 0:12:38One action never normally seen
0:12:38 > 0:12:41if they meet another individual is fin wiggling.
0:12:43 > 0:12:47- Do you see that weird pectoral fin? - Yeah, yeah.- Look at this.
0:12:47 > 0:12:48This is not normal for a dolphin.
0:12:52 > 0:12:54Now, that is very weird.
0:12:55 > 0:12:56That is amazing.
0:12:56 > 0:12:58Well, I don't blame them,
0:12:58 > 0:13:00that's what I like to do when I look in the mirror.
0:13:00 > 0:13:03Well, you're lucky you can, apart from humans there are only
0:13:03 > 0:13:06three kinds of animals that can recognise themselves in the mirror.
0:13:06 > 0:13:10- Chimpanzees, dolphins and elephants, and that's it.- What about dogs?
0:13:10 > 0:13:14- Surely dogs can?- No, not dogs. - What about salamanders?
0:13:14 > 0:13:18No, not dogs, not salamanders, not dragons, not mermaids, not unicorns,
0:13:18 > 0:13:21none of your favourite animals can recognise themselves in the mirror.
0:13:21 > 0:13:24And that's what makes it so amazing that the dolphins can.
0:13:24 > 0:13:27- Well, I really liked seeing them show off.- Well, so did I.
0:13:27 > 0:13:29And, if you enjoyed that, then you're not going to
0:13:29 > 0:13:35believe your eyes this afternoon when we discover magnetic sharks.
0:13:35 > 0:13:37Magnetic sharks? They don't exist.
0:13:37 > 0:13:40Oh, yes, they do, so join us later and we'll Blow Your Mind.