0:00:03 > 0:00:07Meet the Californian ground squirrel.
0:00:07 > 0:00:12It's an endearing little rodent, but it does face a big problem.
0:00:14 > 0:00:16A constant and terrifying threat.
0:00:19 > 0:00:21Rattlesnakes.
0:00:26 > 0:00:29Deadly serpents that hunt by smell.
0:00:33 > 0:00:37Once locked on to a squirrel's scent, there's no escape.
0:00:45 > 0:00:46Or is there?
0:00:46 > 0:00:51You see, these squirrels have a distinctly devious con
0:00:51 > 0:00:53to fool the sinister snakes,
0:00:53 > 0:00:57and central to that con, is this,
0:00:57 > 0:01:01one of the rattlesnake's old, shed skins.
0:01:06 > 0:01:07Just watch this!
0:01:17 > 0:01:18Look at that!
0:01:18 > 0:01:22The squirrel's come over, picked up the skin,
0:01:22 > 0:01:23and started chewing it.
0:01:25 > 0:01:28They rub the mush all over their bodies.
0:01:31 > 0:01:33You see, they're masking their own scent.
0:01:35 > 0:01:38Now, they smell like the snakes instead.
0:01:41 > 0:01:46It's fooling the principal way the ruthless rattlers hunt them down.
0:01:52 > 0:01:56The snakes just can't detect the squirrels.
0:01:56 > 0:01:59It's ingenious, isn't it?
0:01:59 > 0:02:01Absolutely ingenious!
0:02:02 > 0:02:07They use the snakes' own scent to hide themselves.
0:02:09 > 0:02:12Now, that's nature at its most devious.
0:02:13 > 0:02:17And it turns out that these sneaky squirrels
0:02:17 > 0:02:21aren't the only ones tricking other animals to survive.
0:02:33 > 0:02:36Every day, animals face the single greatest challenge
0:02:36 > 0:02:39of their lives - survive, or die.
0:02:42 > 0:02:44They've got to outwit potential predators.
0:02:47 > 0:02:49Find or catch food.
0:02:53 > 0:02:56And then raise the next generation.
0:02:57 > 0:03:01Frankly, the stakes couldn't be higher.
0:03:04 > 0:03:07So, in the face of all of this,
0:03:07 > 0:03:10how on earth can animals increase their chances?
0:03:10 > 0:03:13I mean, would they lie, cheat,
0:03:13 > 0:03:17even steal from one another just to survive?
0:03:17 > 0:03:20Come on, of course they would.
0:03:25 > 0:03:29Join me as I meet the world's sneakiest animals...
0:03:30 > 0:03:33..who will do whatever it takes to survive.
0:03:51 > 0:03:53Now, if there's anywhere on the planet where
0:03:53 > 0:03:59staying alive is a constant struggle, then it's here, the African savanna.
0:04:03 > 0:04:05To avoid the attention of predators,
0:04:05 > 0:04:08most animals' coat colours blend in to the background.
0:04:12 > 0:04:18But one in particular has perfected an incredibly sneaky disguise.
0:04:19 > 0:04:21The zebra.
0:04:21 > 0:04:23No, seriously, I mean it.
0:04:23 > 0:04:24The zebra.
0:04:28 > 0:04:31Let's just stop for a minute and think about these animals -
0:04:31 > 0:04:33in particular their markings.
0:04:33 > 0:04:36I mean, they are striking, stunning animals.
0:04:43 > 0:04:44But, at the same time,
0:04:44 > 0:04:48they might strike you as a little ridiculous when you think about it.
0:04:52 > 0:04:56After all, they're living out here on the plains of Africa,
0:04:56 > 0:05:00which are famed for being alive with predators.
0:05:04 > 0:05:05And yet, look!
0:05:08 > 0:05:10They stick out like a sore thumb.
0:05:12 > 0:05:15So, perhaps this begs the question,
0:05:15 > 0:05:17the age-old question,
0:05:17 > 0:05:21why does the zebra have its stripes?
0:05:23 > 0:05:26Well, over the years, there have been plenty of theories.
0:05:28 > 0:05:30From helping to keep them cool in the heat,
0:05:30 > 0:05:33or attracting a mate...
0:05:35 > 0:05:38..or even a way of identifying each other.
0:05:42 > 0:05:45But to be honest, none of these have stood the test of time.
0:05:47 > 0:05:51Now, ground-breaking new science is suggesting that these
0:05:51 > 0:05:55bold patterns are keeping the zebras safe from their enemies.
0:06:08 > 0:06:10But how?
0:06:10 > 0:06:13Well, perhaps there's a clue in the colours themselves.
0:06:20 > 0:06:23Black and white are the two most contrasting colours.
0:06:23 > 0:06:27When combined, they play tricks on the mind.
0:06:34 > 0:06:37Take a look at this, and don't adjust your sets.
0:06:37 > 0:06:41This is known as the cafe wall illusion.
0:06:41 > 0:06:43Look at the horizontal lines,
0:06:43 > 0:06:46they look sloping, diagonal,
0:06:46 > 0:06:48uneven, right?
0:06:50 > 0:06:53But, just look at this.
0:06:54 > 0:06:59You'll see that there are no skewy or diagonal lines at all.
0:06:59 > 0:07:06In fact, everything is perfectly even and horizontal.
0:07:06 > 0:07:09Before, the lines looked sloping.
0:07:11 > 0:07:15After, they're perfectly straight.
0:07:18 > 0:07:22Black and white patterns can confuse our vision.
0:07:26 > 0:07:32And they are the two most common colours used in optical illusions.
0:07:36 > 0:07:41So, could it be that a phenomenon like this
0:07:41 > 0:07:46could contribute to the whole enigma of the zebra's stripes?
0:07:49 > 0:07:53Well, one man has been investigating exactly this.
0:07:57 > 0:08:02Dr Martin How is an expert in the way that predators see their prey.
0:08:05 > 0:08:08I've been studying animal vision for a number of years now
0:08:08 > 0:08:11and became quite interested in what the zebra's stripes might be doing
0:08:11 > 0:08:14to the visual systems of their main predators.
0:08:18 > 0:08:20They've got these very strong stripes,
0:08:20 > 0:08:23but nobody's really explained convincingly why they're striped.
0:08:28 > 0:08:30Martin's got an exciting theory.
0:08:32 > 0:08:34That the bold, contrasting patterns,
0:08:34 > 0:08:40when viewed by predators, could be creating an optical illusion.
0:08:43 > 0:08:46It's an idea called motion dazzle.
0:08:49 > 0:08:53Let me show you how it works with an example we're all very familiar with.
0:09:02 > 0:09:04Now just watch this.
0:09:04 > 0:09:08If I begin to turn this bicycle wheel,
0:09:08 > 0:09:11you can see that it's moving in a clockwise direction,
0:09:11 > 0:09:14and it looks like it's moving in a clockwise direction.
0:09:14 > 0:09:18But if I turn it more quickly, like this,
0:09:18 > 0:09:22then suddenly something magical happens.
0:09:30 > 0:09:33The wheel appears to be moving in the opposite direction,
0:09:33 > 0:09:36it appears to be going completely backwards.
0:09:46 > 0:09:49It's called the wagon wheel illusion.
0:09:52 > 0:09:54The faster something rotates,
0:09:54 > 0:09:57the more we struggle to process the movement.
0:09:59 > 0:10:02Our brain tries to simplify what we're seeing,
0:10:02 > 0:10:04but it gets the direction wrong.
0:10:11 > 0:10:15To investigate whether something like this could be happening
0:10:15 > 0:10:17with the zebra's monochrome stripes,
0:10:17 > 0:10:21Martin developed a computer model to analyse footage.
0:10:21 > 0:10:24What we've got here is the original footage
0:10:24 > 0:10:26of the zebras moving from left to right,
0:10:26 > 0:10:28and below, we've got the output of the model.
0:10:28 > 0:10:31The brightness of the colour shows you where the movement is happening
0:10:31 > 0:10:34and the colour itself tells you the direction,
0:10:34 > 0:10:36so the green areas are moving to the right,
0:10:36 > 0:10:39and the red areas are moving to the left.
0:10:39 > 0:10:40OK, but there is a mass of red in there,
0:10:40 > 0:10:44does that mean that those parts of those zebra, to the predator,
0:10:44 > 0:10:47look like they're moving completely in the opposite direction,
0:10:47 > 0:10:49- back to the left? - That's exactly right,
0:10:49 > 0:10:53and it demonstrates that it's the stripes that are causing the effect.
0:10:56 > 0:10:57Let's just be clear on this.
0:10:57 > 0:11:02Here, we've isolated the two key colours.
0:11:04 > 0:11:07As the zebras are walking to the right,
0:11:07 > 0:11:12the model should only be showing green, no other colours.
0:11:12 > 0:11:15Remarkably, the red we are seeing
0:11:15 > 0:11:20is suggesting that a predator would perceive the zebras to be moving
0:11:20 > 0:11:23in completely the opposite direction.
0:11:23 > 0:11:25Just like the bike wheel.
0:11:31 > 0:11:35Predators must precisely judge the speed and direction
0:11:35 > 0:11:37of their prey in order to make a kill.
0:11:43 > 0:11:47This research shows that, as zebras start moving,
0:11:47 > 0:11:52the stripes create a miraculous and disorientating illusion.
0:11:53 > 0:11:57Making it harder for the predators to home in on them.
0:12:04 > 0:12:07In a hunt, every second counts.
0:12:07 > 0:12:09So this dazzling form of defence
0:12:09 > 0:12:12could be confusing predators just enough
0:12:12 > 0:12:17for the zebras to escape and live to see another day.
0:12:20 > 0:12:22It's an outstandingly sneaky trick.
0:12:27 > 0:12:30Zebras have transformed themselves
0:12:30 > 0:12:34into a walking, trotting, galloping optical illusion,
0:12:34 > 0:12:38which both deceives and deters their predators.
0:12:38 > 0:12:39If I'm honest with you,
0:12:39 > 0:12:42up until now I've never really given them a second look.
0:12:42 > 0:12:45I've always thought of them as small stripy ponies,
0:12:45 > 0:12:47living out here to be eaten by something more interesting,
0:12:47 > 0:12:48but no longer.
0:12:48 > 0:12:52I now see them as unique and beautiful animals,
0:12:52 > 0:12:55creatures that have pulled off an incredible deception
0:12:55 > 0:12:59to produce one of the most effective anti-predator strategies
0:12:59 > 0:13:01that we have on our planet.
0:13:05 > 0:13:09Motion dazzle is a brilliant way to confuse hunting predators.
0:13:13 > 0:13:17But animals have other ingenious ways to outwit their enemies.
0:13:28 > 0:13:32One creature's sneaky strategy is to avoid being detected
0:13:32 > 0:13:33in the first place.
0:13:45 > 0:13:50You're looking at a northern leaf-tailed gecko,
0:13:50 > 0:13:53and these animals are incredibly difficult to spot.
0:13:55 > 0:13:58Try focusing just here.
0:14:01 > 0:14:07Now that really is a master of disguise.
0:14:26 > 0:14:30I had a book when I was a kid, it had a photograph of one of these,
0:14:30 > 0:14:32and I could barely believe it existed.
0:14:38 > 0:14:41You can only find them here in Northern Queensland,
0:14:41 > 0:14:42in the tropical forest,
0:14:42 > 0:14:45and it is one of the largest geckos in the world.
0:14:49 > 0:14:51They feed at night,
0:14:51 > 0:14:57but it's when they sleep during the day that they have a big problem.
0:15:00 > 0:15:04This forest is alive with hungry eyes.
0:15:06 > 0:15:10All looking to prey on an exposed lizard.
0:15:13 > 0:15:16You see, our gecko is too big to hide away
0:15:16 > 0:15:18or tuck in under bark.
0:15:18 > 0:15:22So, stuck out on a limb in broad daylight,
0:15:22 > 0:15:25it deploys its party trick.
0:15:27 > 0:15:32The gecko has developed an ability that we can only dream of.
0:15:32 > 0:15:33Just watch this.
0:15:37 > 0:15:40It vanishes into thin air.
0:15:48 > 0:15:52The gecko's vanishing act starts with its skin.
0:15:53 > 0:15:57It's covered in a series of strongly contrasting patterns.
0:15:57 > 0:16:00In close up, they really stand out,
0:16:00 > 0:16:05but from a distance, they break up the gecko's body shape,
0:16:05 > 0:16:06and its outline...
0:16:08 > 0:16:12..allowing it to blend seamlessly into any forest background.
0:16:14 > 0:16:17It's known as disruptive camouflage.
0:16:18 > 0:16:20Even their eyes have it.
0:16:26 > 0:16:30But there are other clues the gecko's predators could pick up on.
0:16:31 > 0:16:35Any three-dimensional object, no matter how well camouflaged,
0:16:35 > 0:16:39has the potential to produce a shadow,
0:16:39 > 0:16:44and this shadow is a dead giveaway to any predator.
0:16:45 > 0:16:49To combat this, geckos have very loose skin,
0:16:49 > 0:16:53which they flatten against the trees when they're trying to hide.
0:16:55 > 0:16:59To complete their vanishing act, the geckos have subtle fringes
0:16:59 > 0:17:02that run around the edges of their bodies,
0:17:02 > 0:17:04particularly on their tails,
0:17:04 > 0:17:07and these serve to break up their outline
0:17:07 > 0:17:10and any sharply defined edges.
0:17:13 > 0:17:15By using these principles,
0:17:15 > 0:17:20animals have perfected the ultimate camouflage.
0:17:23 > 0:17:27The effectiveness, the sheer beauty of these devious disguises,
0:17:27 > 0:17:29is quite mind-blowing.
0:17:29 > 0:17:31Just look at these sneaky creatures.
0:17:33 > 0:17:35Can you make it out?
0:17:35 > 0:17:38It's a dead leaf butterfly from Malaysia.
0:17:40 > 0:17:42What about these animals?
0:17:44 > 0:17:47These are pygmy seahorses, from New Guinea.
0:17:50 > 0:17:55And finally, how about the incredible disguise of this hooded grasshopper?
0:18:00 > 0:18:04And, for our leaf-tailed gecko, and yes, it is still here,
0:18:04 > 0:18:09perfecting this disguise means one important thing,
0:18:09 > 0:18:13it can rest - it can sleep here in the open,
0:18:13 > 0:18:16and avoid the attention of predators all day long.
0:18:27 > 0:18:30Now, it's all very well some animals being able to blend
0:18:30 > 0:18:34perfectly into their background, that's clearly a great advantage.
0:18:34 > 0:18:37But what about if these species then want to move
0:18:37 > 0:18:39from one habitat into another?
0:18:40 > 0:18:44Then it could clearly be a disadvantage.
0:18:44 > 0:18:48Unless they had the ability to change their camouflage,
0:18:48 > 0:18:53and, ultimately, if they could continue to change that disguise...
0:18:54 > 0:18:58..they would come up with nature's invisibility cloak.
0:18:58 > 0:19:02Something that you might think is a bit far-fetched,
0:19:02 > 0:19:04but I've got to tell you that it isn't,
0:19:04 > 0:19:09there's a creature living out there right now that can do just that.
0:19:15 > 0:19:17And what a splendid creature it is.
0:19:19 > 0:19:21What do you mean you can't see it?
0:19:21 > 0:19:24It's in the middle there, amongst the seaweed.
0:19:27 > 0:19:29I give you the cuttlefish.
0:19:39 > 0:19:41Unfortunately for them,
0:19:41 > 0:19:44they are one of the most sought-after meals in the ocean.
0:19:46 > 0:19:49Their bodies have no physical protection,
0:19:49 > 0:19:51so they've come up with a cunning defence.
0:19:53 > 0:19:59They transform themselves entirely to match their surroundings.
0:20:03 > 0:20:08In his US-based lab, cuttlefish expert Dr Roger Hanlon
0:20:08 > 0:20:13is investigating how they conjure up these incredible illusions.
0:20:18 > 0:20:22He's presenting the cuttlefish with different backgrounds...
0:20:28 > 0:20:32..and then pulling the rug out from underneath them.
0:20:34 > 0:20:39It reveals just how quickly they can adapt.
0:20:41 > 0:20:43As Roger is discovering,
0:20:43 > 0:20:48the key to this seemingly supernatural power is their skin.
0:20:48 > 0:20:50Well, this is truly amazing,
0:20:50 > 0:20:53perhaps some of the most beautiful skin on Planet Earth,
0:20:53 > 0:20:55and they need elegant skin
0:20:55 > 0:20:58because they have to create these colours and patterns,
0:20:58 > 0:21:00and contrasts to create this camouflage.
0:21:03 > 0:21:05So, in the top layer of the skin
0:21:05 > 0:21:09they have these beautiful pigmented organs, we call them chromatophores.
0:21:12 > 0:21:16Chromatophores are tiny packages of different coloured pigment.
0:21:18 > 0:21:22Each individual chromatophore is pulled and stretched by muscles
0:21:22 > 0:21:28controlled by the brain, turning a dot into a circle of colour.
0:21:30 > 0:21:33The combined effect of three million chromatophores,
0:21:33 > 0:21:35and other specialist cells,
0:21:35 > 0:21:40changes the cuttlefish's colour and pattern in an instant.
0:21:42 > 0:21:45This amazing colour-changing ability
0:21:45 > 0:21:49is made even more remarkable by one astonishing fact.
0:21:51 > 0:21:53Cuttlefish are colour-blind.
0:21:55 > 0:21:57Yes, that's right.
0:21:57 > 0:22:00They can't even see the colours they're trying to match.
0:22:02 > 0:22:06So, how on earth do they match their surroundings quite so perfectly?
0:22:08 > 0:22:12Well, recently Roger and his colleagues have discovered
0:22:12 > 0:22:14the cuttlefish's beautiful secret.
0:22:16 > 0:22:21Dotted across their skin are specialist cells containing opsin.
0:22:23 > 0:22:27It's a protein usually only ever found in eyes.
0:22:29 > 0:22:32So, this is a marvellous strange discovery,
0:22:32 > 0:22:36they seem to have light-detecting molecules distributed in the skin
0:22:36 > 0:22:40and these are the same molecules that are in the retina in the eye.
0:22:42 > 0:22:46In effect, their skin can sense - possibly even "see" - colour.
0:22:50 > 0:22:54But then these great illusionists have another show-stopping trick.
0:22:58 > 0:23:01The cuttlefish have this morphing skin.
0:23:01 > 0:23:04The skin can actually go from flat to three-dimensional,
0:23:04 > 0:23:07think ultimate goose bumps in a human, for example.
0:23:07 > 0:23:09No other animal can do this.
0:23:12 > 0:23:17The cuttlefish morph and change texture to match any surroundings.
0:23:20 > 0:23:21It's an extraordinary ability.
0:23:24 > 0:23:27These clever cuttlefish, and their close relatives, octopus,
0:23:27 > 0:23:32have the most amazing shape-shifting vanishing act
0:23:32 > 0:23:34that I've ever seen.
0:23:39 > 0:23:43And, when it comes to playing hide-and-seek with predators,
0:23:43 > 0:23:47these deceitful creatures are always the winners.
0:23:58 > 0:24:02Camouflage is a wonderfully sneaky and successful way
0:24:02 > 0:24:03to avoid predators.
0:24:06 > 0:24:10So many different animals depend on it to survive.
0:24:13 > 0:24:15But, you know, for even the best-camouflaged animals
0:24:15 > 0:24:16there's a problem.
0:24:16 > 0:24:20You see, the second they move, the illusion is blown.
0:24:20 > 0:24:25It really doesn't matter how well hidden they are, it spoils the trick.
0:24:27 > 0:24:28But nature always finds a way.
0:24:30 > 0:24:34So, could there be an even craftier ploy?
0:24:34 > 0:24:38One that could protect a conniving creature around the clock?
0:24:41 > 0:24:44No matter where they were, or what they did.
0:24:46 > 0:24:51A disguise that all predators would want to avoid all of the time.
0:24:58 > 0:25:01Venomous, toxic, or decidedly deadly.
0:25:04 > 0:25:07Many animals use bright warning colours
0:25:07 > 0:25:09to declare the threat that they pose.
0:25:13 > 0:25:15Predators learn to avoid these animals.
0:25:17 > 0:25:21They know the consequences if they try to eat them.
0:25:23 > 0:25:26But sometimes, all is not as it seems.
0:25:31 > 0:25:37Two snakes, both displaying classic warning colouration.
0:25:37 > 0:25:41Both residents of here, the south-eastern United States.
0:25:41 > 0:25:46But one of these snakes is deadly venomous.
0:25:48 > 0:25:51It's the eastern coral snake.
0:25:54 > 0:25:59The venom is packed with neurotoxins which paralyse the breathing system,
0:25:59 > 0:26:02so one bite is pretty much certainly fatal.
0:26:05 > 0:26:09That would be a snake to avoid.
0:26:09 > 0:26:14But the other snake is a barefaced liar.
0:26:17 > 0:26:21The scarlet king snake is absolutely harmless.
0:26:23 > 0:26:25The big question is,
0:26:25 > 0:26:27which is which?
0:26:33 > 0:26:38Because in a moment, I'm going to take one of these two snakes
0:26:38 > 0:26:41out of the jar, bare-handed.
0:26:42 > 0:26:44So, which one will it be?
0:26:51 > 0:26:54Which would you choose?
0:27:03 > 0:27:05No, I don't think so.
0:27:06 > 0:27:09I'm going to go for this snake.
0:27:11 > 0:27:17This snake is the scarlet king snake.
0:27:17 > 0:27:19It's the faker.
0:27:19 > 0:27:22And just look at it,
0:27:22 > 0:27:26it is absolutely beautiful.
0:27:30 > 0:27:32In this neck of the woods,
0:27:32 > 0:27:36it helps to remember a rhyme that could save your life.
0:27:36 > 0:27:39"Red touches yellow, could kill a fellow.
0:27:40 > 0:27:43"Red touches black, friend to Jack."
0:27:46 > 0:27:49And here, the red-and-black bands are touching,
0:27:49 > 0:27:52so this is our harmless king snake.
0:27:54 > 0:27:59Round here, this snake is certainly on the menu for many larger animals.
0:27:59 > 0:28:02So, it's evolved a sneaky tactic.
0:28:07 > 0:28:11This is a classic case of imitation.
0:28:11 > 0:28:16The harmless king snake is mimicking its deadly rival,
0:28:16 > 0:28:17the coral snake,
0:28:17 > 0:28:24in the hope that predators will buy this con and leave it well alone.
0:28:24 > 0:28:26Well, that's the theory at least.
0:28:26 > 0:28:28But I see a problem.
0:28:28 > 0:28:33You see, they're not exactly the same, are they?
0:28:33 > 0:28:40So, could this mimicry really confer protection on this cheating snake?
0:28:40 > 0:28:43Unbelievably, until recently,
0:28:43 > 0:28:48it had never actually been tested in the field, that is until now.
0:28:52 > 0:28:54Professor David Pfennig is an expert
0:28:54 > 0:28:56in the king snake's masterful mimicry.
0:29:01 > 0:29:04Earlier in the year, he set out replicas
0:29:04 > 0:29:06of both snakes,
0:29:06 > 0:29:08in front of camera traps.
0:29:11 > 0:29:12He's investigating...
0:29:14 > 0:29:19..how predators really react to these warning colours.
0:29:31 > 0:29:33I can't wait to see the results.
0:29:33 > 0:29:35So, David, how did the experiment go?
0:29:35 > 0:29:39It worked out fabulous, and you can see we found a real diversity
0:29:39 > 0:29:41of animal life appearing on our videos.
0:29:48 > 0:29:50OK, so, a great range of species,
0:29:50 > 0:29:54but at least two of those animals are potential predators of the snake.
0:29:57 > 0:30:00The grey foxes and the coyotes would be predators of these snakes.
0:30:00 > 0:30:03The raccoons would probably be, as well.
0:30:03 > 0:30:06When we look at the reactions of these predators to the snakes
0:30:06 > 0:30:09we find that they're treating them as if they were real snakes.
0:30:15 > 0:30:17But surely, the bright warning colouration
0:30:17 > 0:30:20has to be putting off the majority of attacks?
0:30:20 > 0:30:21That's right.
0:30:21 > 0:30:25Generally, they're not attacking our fake snakes, they're avoiding them,
0:30:25 > 0:30:28and you can see this avoidance in several of these clips.
0:30:29 > 0:30:31Sometimes they do go after them,
0:30:31 > 0:30:34and they do attack them, at a very low frequency though.
0:30:34 > 0:30:37What do you see in terms of a difference between the number
0:30:37 > 0:30:41of fake coral snakes and the number of fake king snakes being attacked?
0:30:41 > 0:30:43They're equally likely to be attacked.
0:30:43 > 0:30:46So even though the coral snake and the king snake
0:30:46 > 0:30:49have different ring order, predators are avoiding both.
0:30:52 > 0:30:55So, despite not looking EXACTLY the same,
0:30:55 > 0:31:00the mimetic king snake is still gaining all of the advantage
0:31:00 > 0:31:03of its phony warning colours.
0:31:03 > 0:31:05The reason why that works
0:31:05 > 0:31:08is that the coral snake is really, really deadly,
0:31:08 > 0:31:11it can kill an adult human, it could kill any of these predators.
0:31:14 > 0:31:17So, just vaguely looking like it is good enough to get you by.
0:31:20 > 0:31:24Just as I gambled with my life earlier...
0:31:26 > 0:31:28No.
0:31:28 > 0:31:32..if a predator wanted to eat one of these two snakes
0:31:32 > 0:31:34and picked the wrong one,
0:31:34 > 0:31:37it could cost them their life.
0:31:39 > 0:31:42So, they tend to play it safe,
0:31:42 > 0:31:46avoiding any snake with obvious warning colours.
0:31:51 > 0:31:55Mimicry really is an excellent strategy for survival.
0:31:55 > 0:31:59It's a brilliantly cunning way to protect yourself from predators
0:31:59 > 0:32:0124 hours a day.
0:32:01 > 0:32:05So, it's hardly surprising that, when one species evolves
0:32:05 > 0:32:09to be deadly dangerous, others sneak in and copy them.
0:32:12 > 0:32:16Harmless hoverflies copy the warning colours of stinging bees.
0:32:18 > 0:32:23This bushveld lizard mimics the markings of the oogpister.
0:32:26 > 0:32:30A tenacious beetle that sprays formic acid.
0:32:34 > 0:32:38Targeting the eyes, it can cause temporary blindness,
0:32:38 > 0:32:41definitely something worth impersonating then.
0:32:43 > 0:32:46The little lizard even adopts a silly walk
0:32:46 > 0:32:49to perfect the parody.
0:33:04 > 0:33:08But how about this amazing new discovery?
0:33:10 > 0:33:12The ball of bright ginger fluff
0:33:12 > 0:33:17is the chick of the secretive cinereous mourner.
0:33:20 > 0:33:23It starts worming around in the nest.
0:33:25 > 0:33:28Because it's impersonating one of these,
0:33:28 > 0:33:31a highly noxious caterpillar.
0:33:34 > 0:33:37This is the first time it's ever been filmed.
0:33:42 > 0:33:46It's absolutely extraordinary, isn't it,
0:33:46 > 0:33:51a tiny chick pretending to be a deadly poisonous caterpillar!
0:33:51 > 0:33:56But you know, mimicry isn't always about changing your appearance
0:33:56 > 0:33:58or your behaviour.
0:33:58 > 0:34:00There is one unlikely impersonator
0:34:00 > 0:34:04who uses mimicry in a completely different way.
0:34:10 > 0:34:14And I've come here to this unusual location
0:34:14 > 0:34:19on the outskirts of Sacramento to meet it.
0:34:19 > 0:34:22This was a building site, it was planned,
0:34:22 > 0:34:24but the houses were never put up.
0:34:32 > 0:34:36But that hasn't stopped one family from moving in
0:34:36 > 0:34:38to number 1, Bluff Way.
0:34:50 > 0:34:51Burrowing owls!
0:34:55 > 0:35:01And look at them, they're absolutely delightful little birds.
0:35:05 > 0:35:07These are not normal owls.
0:35:10 > 0:35:12Running around on the ground.
0:35:14 > 0:35:16Hanging out in the daytime.
0:35:19 > 0:35:23Oh, and as the name suggests, they live down burrows.
0:35:33 > 0:35:35This family has five youngsters,
0:35:35 > 0:35:39which are just starting to explore outside the burrow.
0:35:39 > 0:35:42And that burrow provides excellent protection
0:35:42 > 0:35:45from any aerial predators, there's no doubt about that,
0:35:45 > 0:35:49but it's not quite so good when it comes to ground predators.
0:35:52 > 0:35:55In this unusual neighbourhood...
0:35:57 > 0:36:00..a stray dog is a real threat to our young family.
0:36:09 > 0:36:12So, to deter ground predators,
0:36:12 > 0:36:15burrowing owls deploy a really sneaky strategy.
0:36:15 > 0:36:19A willing volunteer should help demonstrate what I mean.
0:36:21 > 0:36:25Meet Ruby, she's a three-year-old hand-reared burrowing owl.
0:36:26 > 0:36:29Ruby can do something which is very pertinent
0:36:29 > 0:36:31to what we're interested in.
0:36:31 > 0:36:32When she wants to.
0:36:37 > 0:36:40Like I said, when she wants to.
0:36:52 > 0:36:54No, nothing, not a peep.
0:36:58 > 0:37:01OK, I won't look at her, and then she'll probably do it.
0:37:06 > 0:37:08CROW CAWS OVERHEAD
0:37:08 > 0:37:09She doesn't like the crow.
0:37:25 > 0:37:30Then, finally, she does what I wanted to see.
0:37:30 > 0:37:32OWL HISSES
0:37:40 > 0:37:42Look at that.
0:37:44 > 0:37:46In fact, it's the sound,
0:37:46 > 0:37:51it's the copycat call that's key to the burrowing owl's defence.
0:37:53 > 0:37:56Why do you think she's making THAT sound?
0:37:56 > 0:37:58It's tricky, isn't it?
0:37:58 > 0:38:00I'll give you a clue.
0:38:00 > 0:38:03I can tell you that Ruby shares her space
0:38:03 > 0:38:06with a species of pretty noxious snake.
0:38:11 > 0:38:16Rattlesnakes are highly venomous, and known for their aggression.
0:38:18 > 0:38:21The famous rattle is a warning.
0:38:25 > 0:38:28Steer well clear, or I'll bite.
0:38:29 > 0:38:33And, like our owls, they also hide down burrows.
0:38:34 > 0:38:37So, that's what the owls are up to.
0:38:39 > 0:38:43If they can accurately impersonate an angry rattlesnake...
0:38:45 > 0:38:47..deep in a dark burrow,
0:38:47 > 0:38:51then no predator in its right mind is going to bother them.
0:38:53 > 0:38:58But, for this impersonation to work, it has to be totally convincing.
0:38:59 > 0:39:02So, does it work? Does it actually fool other animals?
0:39:02 > 0:39:04Let's put it to the test.
0:39:08 > 0:39:10Now, if you were paying attention
0:39:10 > 0:39:12at the very beginning of this programme...
0:39:16 > 0:39:20..you'll know that these endearing Californian ground squirrels
0:39:20 > 0:39:23live in constant fear of rattlesnakes,
0:39:23 > 0:39:25and of course rightly so.
0:39:27 > 0:39:33Because out here, 70% of the rattlesnake's diet is squirrel.
0:39:34 > 0:39:37If there's one animal whose life definitely depends
0:39:37 > 0:39:41on its ability to recognise a rattlesnake's rattle,
0:39:41 > 0:39:42then this is it.
0:39:45 > 0:39:47If the owl's impersonation
0:39:47 > 0:39:50can fool these guys, it will fool any predator.
0:39:50 > 0:39:53These are the perfect test subject.
0:40:00 > 0:40:03The plucky little squirrels have an audacious approach to
0:40:03 > 0:40:05tackling their number one nemesis.
0:40:08 > 0:40:14Rather than run, they mob the snake, waving their tails frantically.
0:40:15 > 0:40:18SNAKE RATTLES
0:40:18 > 0:40:21It's the squirrel's way of saying, "I've seen you
0:40:21 > 0:40:23"so don't try anything clever."
0:40:38 > 0:40:41OK, we've got the squirrel here. Let's see what happens
0:40:41 > 0:40:44when I play the owl's rattlesnake call.
0:40:46 > 0:40:47HE PLAYS OWL CALL
0:40:47 > 0:40:49Here we go.
0:40:49 > 0:40:53HE PLAYS OWL CALL
0:40:56 > 0:40:57Look at that!
0:40:58 > 0:41:02The squirrel's wagging its tail and that's what they do
0:41:02 > 0:41:05when they sense there's a rattlesnake about.
0:41:07 > 0:41:11So, this little chap is convinced that there's a snake in the grass.
0:41:13 > 0:41:15SOUND OF OWL HISSING
0:41:15 > 0:41:18Little does it know it's an owl doing an impersonation.
0:41:18 > 0:41:21OWL HISSES
0:41:21 > 0:41:22What about that?
0:41:25 > 0:41:29And for our young family, living in a tough urban environment...
0:41:31 > 0:41:35..a sneaky trick like this is helping them to survive.
0:41:37 > 0:41:39SQUAWKING
0:41:41 > 0:41:45I don't know. Just when you think that you might have seen
0:41:45 > 0:41:50and heard it all, up pops an owl that makes a sound like a rattlesnake!
0:41:50 > 0:41:52I mean, you couldn't make it up, could you?
0:41:52 > 0:41:56And it works because by turning themselves into a ventriloquist,
0:41:56 > 0:41:59these animals are replicating the sound of that deadly
0:41:59 > 0:42:04reptile in the burrow at a time when their chicks are at their most
0:42:04 > 0:42:07vulnerable. And it's saving their lives, there's no doubt about it.
0:42:15 > 0:42:20But what if an animal used mimicry not to fool its predators
0:42:20 > 0:42:23but to trick others of its own species?
0:42:25 > 0:42:26Sounds far-fetched
0:42:26 > 0:42:31but an amazing new discovery could well be an example of exactly that.
0:42:41 > 0:42:47So, lions. What do we need to know about lions?
0:42:48 > 0:42:51Well, firstly, they're very territorial.
0:42:58 > 0:43:00Each pride defends a home patch...
0:43:02 > 0:43:05..which they absolutely depend on to survive.
0:43:10 > 0:43:13Secondly, it's the males who guard that territory.
0:43:15 > 0:43:18LION ROARS
0:43:22 > 0:43:27Everything clear? Good, because here comes the sneaky bit.
0:43:31 > 0:43:36Deep in Botswana's Okavango Delta,
0:43:36 > 0:43:39there's an extraordinary lion
0:43:39 > 0:43:41that's re-writing all of the rules.
0:43:43 > 0:43:45This is Mmamoriri.
0:43:48 > 0:43:53A perfectly ordinary male lion, complete with a characteristic mane.
0:43:54 > 0:43:58Right? Well, actually, no. Wrong!
0:44:01 > 0:44:05You see, Mmamoriri is a lioness.
0:44:05 > 0:44:06MUSIC: She's A Lady by Tom Jones
0:44:06 > 0:44:08# Well, she's all you'd ever want
0:44:08 > 0:44:10# She's the kind I'd like to flaunt
0:44:10 > 0:44:12# And take to dinner
0:44:14 > 0:44:16# Well, she always knows her place
0:44:16 > 0:44:18# She's got style, she's got grace
0:44:18 > 0:44:19# She's a winner
0:44:22 > 0:44:23# She's a lady
0:44:24 > 0:44:26# Whoa, whoa, whoa
0:44:26 > 0:44:27# She's a lady
0:44:28 > 0:44:31# Talkin' about that little lady... #
0:44:31 > 0:44:36Yes, I know she's got a full mane, but I promise you, she is all woman.
0:44:36 > 0:44:39# ..Talkin' about that little lady
0:44:41 > 0:44:44# And the lady is mine
0:44:44 > 0:44:47# Yeah, yeah, she's a lady
0:44:48 > 0:44:51# Oh, Lord, she's a lady. #
0:44:51 > 0:44:56Not only does Mmamoriri look like a male, she acts like a male.
0:44:57 > 0:45:01Even her roar is deeper and more masculine.
0:45:01 > 0:45:04LION ROARS
0:45:06 > 0:45:09Right now, there are thought to be five of these maned
0:45:09 > 0:45:12lionesses in the Okavango.
0:45:15 > 0:45:19And this is the first time that one of them has ever been filmed.
0:45:24 > 0:45:29They probably all have the same genetic mutation,
0:45:29 > 0:45:32which has created an imbalance of hormones.
0:45:40 > 0:45:45This is extraordinary stuff but what does it mean for this pride?
0:45:46 > 0:45:48Well, scientists suspect that
0:45:48 > 0:45:52because Mmamoriri mimics a male, rivals might think
0:45:52 > 0:45:56there are more males in her pride than there actually are.
0:45:58 > 0:46:02If they can increase their territory because of this, then it would
0:46:02 > 0:46:06really improve her pride's survival chances.
0:46:09 > 0:46:13This mutation could even be the start of a new
0:46:13 > 0:46:16and very devious lion strategy.
0:46:18 > 0:46:23Evolution happening right before our eyes with one of the most
0:46:23 > 0:46:25iconic animals on the planet.
0:46:26 > 0:46:27It's incredible.
0:46:40 > 0:46:44Mimicry is a successful survival strategy
0:46:44 > 0:46:47used by animals the world over.
0:46:47 > 0:46:51Impersonating others has entirely changed the way that animals
0:46:51 > 0:46:54look and even how they behave.
0:46:58 > 0:47:03But what if animals could adapt their behaviour and make
0:47:03 > 0:47:09deliberate, strategic decisions about when and how to trick others?
0:47:11 > 0:47:15Well, then, they could pull off the sneakiest con tricks of all.
0:47:17 > 0:47:23One of these animal hustlers lives here, in the forests of Panama...
0:47:27 > 0:47:29..white-faced capuchins.
0:47:33 > 0:47:36This group are a close-knit family.
0:47:38 > 0:47:44Together, they defend a territory that they depend upon to survive.
0:47:44 > 0:47:47But other monkey troops are trying to take their turf.
0:47:52 > 0:47:57And as a consequence of that, these monkeys are always in conflict.
0:48:12 > 0:48:14Fighting is a dangerous business.
0:48:19 > 0:48:21Injuries are common.
0:48:26 > 0:48:31In fact, more capuchins are killed by each other than by predators.
0:48:33 > 0:48:36The stakes couldn't be higher.
0:48:38 > 0:48:41Guarding a territory obviously takes teamwork.
0:48:41 > 0:48:47An individual capuchin can't keep an invading troop out on its own
0:48:47 > 0:48:49and obviously, from that troop's point of view,
0:48:49 > 0:48:53it makes sense to look after the territory. They need it to survive.
0:48:53 > 0:48:56But let's just stop for a moment
0:48:56 > 0:49:00and think about the implications on the individual monkeys.
0:49:05 > 0:49:09Yes, it's their duty to help defend the territory...
0:49:10 > 0:49:15..but that takes time and energy, and then
0:49:15 > 0:49:18there's the likelihood of getting seriously injured.
0:49:20 > 0:49:25And for a monkey like this, that is a huge dilemma, and it's
0:49:25 > 0:49:30led to the evolution of some extraordinarily treacherous tactics.
0:49:34 > 0:49:37These monkeys are part of a long-term study.
0:49:39 > 0:49:43Leading the research is primatologist Meg Crofoot.
0:49:46 > 0:49:51She's going to show me just how sneaky these monkeys can be.
0:49:53 > 0:49:56By playing a recording of a neighbouring troop,
0:49:56 > 0:50:00she's simulating a territorial invasion.
0:50:00 > 0:50:02SOUND OF MONKEY CHATTER
0:50:02 > 0:50:05That's the big male, and there's a female,
0:50:05 > 0:50:07looking towards the speaker with a baby on her back.
0:50:09 > 0:50:12On the ground right here, look at that.
0:50:12 > 0:50:14That's the alpha male in this group.
0:50:14 > 0:50:17- Well, that's certainly got a response from him.- Yup.
0:50:20 > 0:50:22- Here we go, one of the juveniles. - Yes, yes.
0:50:24 > 0:50:26Wow!
0:50:26 > 0:50:30- Look, look, look! Two more there. - Two more there.- Yeah.
0:50:30 > 0:50:33So, we've seen five monkeys come this way - the big male,
0:50:33 > 0:50:36the three juveniles and that one female with the baby on her back.
0:50:36 > 0:50:38But two of the females looked at the speaker
0:50:38 > 0:50:40and didn't come forward at all.
0:50:42 > 0:50:44- They didn't seem to want to get involved in...- No, they didn't.
0:50:44 > 0:50:47- ..looking after their territory.- No.
0:50:49 > 0:50:52I just saw two monkeys cheating their own family...
0:50:54 > 0:50:57..in a social species that's supposed to work together!
0:51:00 > 0:51:03This new discovery has surprised everyone.
0:51:04 > 0:51:11But what's really interesting is that some days, these same two females do
0:51:11 > 0:51:15respond to the recordings, they do rush in to help.
0:51:15 > 0:51:18Another day, a different monkey cheats the troop.
0:51:18 > 0:51:21To a lesser and greater extent, they're all up to it.
0:51:21 > 0:51:25So, there's definitely a sneaky strategy in play here.
0:51:25 > 0:51:28MONKEYS SCREECH
0:51:29 > 0:51:33So, if the same monkeys don't cheat all of the time, that means
0:51:33 > 0:51:35they must be making decisions every time there's a potential
0:51:35 > 0:51:38conflict as to whether to cheat or not.
0:51:38 > 0:51:40Yes, I think that's definitely true.
0:51:40 > 0:51:42It seems to be an interesting tension between the
0:51:42 > 0:51:45likelihood that the group is going to be able to win without you
0:51:45 > 0:51:49and your own sort of personal desire to avoid risk entirely.
0:51:51 > 0:51:56These monkeys have weighed things up and decided to cheat the group.
0:51:58 > 0:52:00But it's a huge risk.
0:52:00 > 0:52:05After all, it could jeopardise their own family's long-term survival.
0:52:06 > 0:52:11But for the individual monkey, if it means avoiding injury,
0:52:11 > 0:52:13then the con pays off.
0:52:19 > 0:52:23Being able to decide which trick to pull out of the bag
0:52:23 > 0:52:29and when is critical to a successful sneaky strategy.
0:52:29 > 0:52:32So, what is the ultimate animal hustle?
0:52:32 > 0:52:37Well, one creature really will do whatever it takes to survive.
0:52:38 > 0:52:43The horned lizard, what an animal, look at it!
0:52:43 > 0:52:45I'm absolutely smitten.
0:52:45 > 0:52:50To me, this is gorgeous, this defines cute.
0:52:50 > 0:52:54And, of course, you can see how it gets its name.
0:52:54 > 0:52:57This super-spiky skin,
0:52:57 > 0:53:02and this dinosaur appearance normally protects it from predators.
0:53:02 > 0:53:04Normally. But occasionally,
0:53:04 > 0:53:10this little animal has to pull off the riskiest con of all.
0:53:13 > 0:53:17Horned lizards lay eggs and then carefully bury them.
0:53:19 > 0:53:22Then they stand guard duty.
0:53:24 > 0:53:26Her camouflage keeps her concealed
0:53:26 > 0:53:29as she scans the horizon for any potential danger.
0:53:31 > 0:53:36And what's this? A western patch-nosed snake.
0:53:36 > 0:53:38That's not good.
0:53:38 > 0:53:42She eyes him up, but she is not the one in danger.
0:53:42 > 0:53:46You see, this is an egg-eating snake.
0:53:46 > 0:53:49There's no point in staying hidden now.
0:53:50 > 0:53:53It's protecting the eggs that's important.
0:53:53 > 0:53:54She charges into battle.
0:54:06 > 0:54:09Her frenzied attack drives the snake away.
0:54:17 > 0:54:22It's a tactic that works when it comes to protecting eggs.
0:54:24 > 0:54:29So, a horned lizard like this can recognise its adversary,
0:54:29 > 0:54:32measure the threat to its eggs
0:54:32 > 0:54:37and then decide on the appropriate defensive response.
0:54:37 > 0:54:41All very clever stuff, but what about if the tables are turned?
0:54:44 > 0:54:48Well, then the lizard has to change its strategy -
0:54:48 > 0:54:52that's when things get REALLY interesting.
0:54:57 > 0:55:00A coachwhip snake -
0:55:00 > 0:55:03this snake eats lizards
0:55:03 > 0:55:05and she knows it.
0:55:17 > 0:55:19First, she tries a simple scam -
0:55:19 > 0:55:26puffing herself up to look bigger, more intimidating.
0:55:28 > 0:55:31But this doesn't fool the persistent snake.
0:55:33 > 0:55:37This is now a matter of life and death.
0:55:40 > 0:55:45So, she's forced into pulling the sneakiest strategy of all,
0:55:45 > 0:55:47her greatest deception.
0:55:53 > 0:55:57She's faked her own death.
0:56:03 > 0:56:06If the snake doesn't buy the con,
0:56:06 > 0:56:10this is going to backfire in a spectacularly bad way.
0:56:10 > 0:56:15But snakes, you see, never eat dead animals,
0:56:15 > 0:56:17unless they've made the kill themselves.
0:56:30 > 0:56:33Completely confused, the snake slopes off.
0:56:36 > 0:56:38A quick peek to check the coast is clear...
0:56:42 > 0:56:45..and she springs back to life...
0:56:48 > 0:56:52..ready for whatever life throws at her next.
0:56:56 > 0:57:02Surely this has to be the ultimate predator response?
0:57:02 > 0:57:03Faking your own death,
0:57:03 > 0:57:07right under the nose of your most dangerous enemy?
0:57:07 > 0:57:09It's audacious and it's gutsy.
0:57:09 > 0:57:15And what's more, this little lizard actually decides when to fight
0:57:15 > 0:57:19and when to pull off that show-stopping deception
0:57:19 > 0:57:21and, by making that decision,
0:57:21 > 0:57:26it can protect its eggs and keep itself alive. What about that?
0:57:26 > 0:57:32In fact, I'm going to give the horned lizard a very rare ten out of ten,
0:57:32 > 0:57:35not just because of the behaviour,
0:57:35 > 0:57:38but also cos I'm totally in love with it. Look at it!
0:57:38 > 0:57:41It's my little dinosaur!
0:57:43 > 0:57:47All these extraordinarily sneaky animals have gone
0:57:47 > 0:57:50to incredible lengths to fool their enemies...
0:57:51 > 0:57:54..and outwit their predators.
0:57:55 > 0:58:01By using deception, they've overcome one of life's greatest challenges -
0:58:01 > 0:58:03staying alive.
0:58:09 > 0:58:11Next time,
0:58:11 > 0:58:17we meet the animals using sneaky strategies to find food.
0:58:17 > 0:58:20The hunters, the con artists
0:58:20 > 0:58:25and thieves who will stop at nothing to get a meal.
0:58:25 > 0:58:28These animals definitely don't play by the rules.