Episode 5

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0:00:02 > 0:00:05We live in a very weird world.

0:00:09 > 0:00:13And the more we discover about our planet, the stranger it gets.

0:00:14 > 0:00:20Every day, new stories reach us, stories that surprise us...

0:00:20 > 0:00:22What is that?

0:00:22 > 0:00:23'..shock us...'

0:00:23 > 0:00:25- Whoa! That is so cool.- Oh, my God!

0:00:25 > 0:00:29..and sometimes, even scare us.

0:00:29 > 0:00:30Argh!

0:00:30 > 0:00:32Oh, my God.

0:00:32 > 0:00:37We've scoured the globe to bring you the most curious creatures...

0:00:38 > 0:00:40..the most extraordinary people...

0:00:40 > 0:00:44I can stick almost anything to my skin without no glue.

0:00:44 > 0:00:46..and the most bizarre behaviour.

0:00:49 > 0:00:55Using eyewitness accounts and expert opinion to explore a weird world

0:00:55 > 0:00:59of unexplained underwater blobs,

0:00:59 > 0:01:02flying goats

0:01:02 > 0:01:04and glow-in-the-dark fish.

0:01:06 > 0:01:12We examine the evidence, test the theories,

0:01:12 > 0:01:15to work out what on earth is going on.

0:01:34 > 0:01:37In this episode - discover what made a monster wave

0:01:37 > 0:01:40appear out of nowhere.

0:01:40 > 0:01:43Oh, she's going.

0:01:43 > 0:01:48How vampires suddenly appeared in America's Great Lakes.

0:01:48 > 0:01:53And whether great white sharks really enjoy a bit of head-banging.

0:01:56 > 0:01:59And for our first dip into the world of weirdness,

0:01:59 > 0:02:01we head to the seaside.

0:02:04 > 0:02:07Australia, 2015.

0:02:07 > 0:02:12A group of friends decide to pack their swimming gear and head to

0:02:12 > 0:02:16some rock pools on the picturesque coast 50km south of Sydney.

0:02:17 > 0:02:22It was quite a nice day, probably high 20s, very clear,

0:02:22 > 0:02:24sunny, warm day.

0:02:27 > 0:02:30Nothing out of the ordinary, so it wasn't wild weather or anything

0:02:30 > 0:02:32like that, so it was quite a nice day

0:02:32 > 0:02:34to go for a walk and then a swim.

0:02:34 > 0:02:38Sun, warm seas and calm, crystal clear water.

0:02:38 > 0:02:40What could possibly go wrong?

0:02:42 > 0:02:46We put our things down and decided that we'd go in one at a time,

0:02:46 > 0:02:49so Mika went in first.

0:02:51 > 0:02:54We were watching, Alex and I were watching him in the distance.

0:02:54 > 0:02:56And then,

0:02:56 > 0:02:59all of a sudden, we saw a really, really big wave

0:02:59 > 0:03:02coming from the background...

0:03:02 > 0:03:04Oh, get out!

0:03:04 > 0:03:07..which completely shocked us and we were standing there

0:03:07 > 0:03:08screaming out to Mika.

0:03:11 > 0:03:13Before we knew it,

0:03:13 > 0:03:19he and countless other people were being dragged along the rocks.

0:03:19 > 0:03:25I have never seen anything like that first-hand and the force of it...

0:03:25 > 0:03:28The water reached us and we were metres and metres inland.

0:03:29 > 0:03:34I'd say it was probably two or three times higher than what I would have

0:03:34 > 0:03:37considered a big wave previously.

0:03:37 > 0:03:40The wave had taken everyone by surprise.

0:03:40 > 0:03:44And as the injured clambered their way back to the shore,

0:03:44 > 0:03:46the questions started flying.

0:03:47 > 0:03:52Everyone wanted to know where this freak wave had come from.

0:03:52 > 0:03:55And how could something like this appear from nowhere?

0:04:01 > 0:04:05Most of the waves that we see are either caused by swell or by wind

0:04:05 > 0:04:08blowing on the surface of the oceans.

0:04:08 > 0:04:11It's a bit like when I blow on this water, making the ripples.

0:04:14 > 0:04:17And of course, the stronger the wind, the bigger the waves.

0:04:20 > 0:04:22But here's the weird thing -

0:04:22 > 0:04:24on that day that Lisa and her friends

0:04:24 > 0:04:29decided to take a dip in the rock pools, there was no wind.

0:04:29 > 0:04:31It was perfectly calm.

0:04:31 > 0:04:34And weather can't change on a whim.

0:04:36 > 0:04:39On a calm day, all the waves would be small.

0:04:41 > 0:04:44And on a windy day, all the waves would be big.

0:04:44 > 0:04:47Not just one of them.

0:04:47 > 0:04:51So, if wind alone can't explain a single giant wave,

0:04:51 > 0:04:55did the blame lie with another force of nature altogether?

0:05:00 > 0:05:03When earthquakes happen near or under the sea,

0:05:03 > 0:05:07it triggers the mother of all monster waves - called a tsunami.

0:05:11 > 0:05:14In deep water, they're almost imperceptible.

0:05:14 > 0:05:17But a tsunami can cross entire oceans

0:05:17 > 0:05:20at speeds of up to 600mph.

0:05:22 > 0:05:25When they hit the shore, they slow down,

0:05:25 > 0:05:30allowing the fast-moving water behind to catch up and in this way,

0:05:30 > 0:05:33a huge wave can appear out of the blue.

0:05:39 > 0:05:41So, was this wave a tsunami?

0:05:41 > 0:05:43Well, no, it wasn't.

0:05:43 > 0:05:46You see, tsunamis are typically formed by seismic activity.

0:05:46 > 0:05:51They involve multiple waves and affect many miles of coastline.

0:05:51 > 0:05:54This wave was altogether different.

0:05:54 > 0:05:56It only affected a tiny part of the coast

0:05:56 > 0:05:58and it came and went very quickly.

0:05:58 > 0:06:01So, was it an anomaly, just a freak?

0:06:01 > 0:06:03Is that possible?

0:06:04 > 0:06:08Rogue waves, they're also called freak waves, extreme waves,

0:06:08 > 0:06:11giant waves. There's lots of different terminology for them,

0:06:11 > 0:06:14and essentially, they are waves that appear within a sea state

0:06:14 > 0:06:18unexpectedly, substantially taller than any of the surrounding waves.

0:06:22 > 0:06:23They are quite hard to predict.

0:06:23 > 0:06:26Rogue waves do quite often appear from nowhere.

0:06:26 > 0:06:29There's different causes that can make them appear,

0:06:29 > 0:06:31so they can occur in any sea state, essentially.

0:06:33 > 0:06:36So, the wave at the rock pools wasn't unique.

0:06:36 > 0:06:39Giant waves can appear anywhere.

0:06:39 > 0:06:43Understanding how could help prevent a disaster, but then,

0:06:43 > 0:06:48understanding anything called a rogue or a freak is complicated.

0:06:52 > 0:06:53Hmm, yes.

0:06:53 > 0:06:56But why is it so complicated?

0:06:56 > 0:07:00Well, firstly, it's because we are dealing with a liquid,

0:07:00 > 0:07:04and when you apply a force to a liquid, it changes shape,

0:07:04 > 0:07:06just like when I drop this marble in here.

0:07:06 > 0:07:09And at the point of the force touching the liquid,

0:07:09 > 0:07:13you can see the shape changing as those ripples radiate away.

0:07:13 > 0:07:17But how about if I apply multiple forces at the same time?

0:07:23 > 0:07:27Then what we've got is, effectively, chaos,

0:07:27 > 0:07:31with the ripples radiating from each one of those marbles,

0:07:31 > 0:07:35but also what we have is an enhanced probability that some

0:07:35 > 0:07:36of those ripples will meet...

0:07:41 > 0:07:45..to form waves, which are double the height of his single ripple.

0:07:45 > 0:07:49And basically, that's how we get rogue waves.

0:07:52 > 0:07:55Only the world isn't a fish tank.

0:07:55 > 0:07:59Our oceans are massive and cover 70% of the planet.

0:08:02 > 0:08:05Instead of lots of marbles, they have storms,

0:08:05 > 0:08:09all happening independently and separated by vast distances.

0:08:13 > 0:08:16Each storm creates waves that can travel for miles.

0:08:19 > 0:08:22When two of these waves meet, they can form a bigger wave,

0:08:22 > 0:08:24but there's more.

0:08:26 > 0:08:31Surging currents and an undulating sea floor also play a part.

0:08:32 > 0:08:35When all of these elements come together...

0:08:39 > 0:08:41..a rogue wave can form,

0:08:41 > 0:08:45and that's what happened at the rock pools that day.

0:08:49 > 0:08:53Scientists know what ingredients are needed to make a rogue wave,

0:08:53 > 0:08:55but they just can't yet predict them.

0:08:57 > 0:09:02To work out the recipe, they need to analyse vast amounts of data,

0:09:02 > 0:09:05but the hope is that one day maths will provide the answer.

0:09:09 > 0:09:13Our oceans are phenomenal places.

0:09:13 > 0:09:16The sheer size and power can be intimidating.

0:09:16 > 0:09:18But, that said,

0:09:18 > 0:09:22I wouldn't let a rogue wave put you off from taking a dip in the sea.

0:09:22 > 0:09:25After all, these are rare events.

0:09:25 > 0:09:26The clue is in the name.

0:09:31 > 0:09:34From stories of weird and wonderful weather,

0:09:34 > 0:09:38we now head off to meet some of nature's ultimate survivors.

0:09:43 > 0:09:46These are North America's Great Lakes.

0:09:48 > 0:09:50It looks placid here,

0:09:50 > 0:09:54but there's something sinister lurking beneath the surface.

0:09:58 > 0:10:01The Great Lakes fish are under attack from an animal

0:10:01 > 0:10:05that's scraping away their flesh to feed on the blood.

0:10:10 > 0:10:15Millions of fish have already died, which in turn,

0:10:15 > 0:10:18has caused panic in the fishing community.

0:10:18 > 0:10:20You'd see warnings from fishermen, say,

0:10:20 > 0:10:23out on Lake Michigan telling the people at Lake Superior,

0:10:23 > 0:10:25"Man, look at what happened to us down here."

0:10:29 > 0:10:32I hate to say it, but there's nothing that can be done to stop

0:10:32 > 0:10:36these and your way of life is in danger as well.

0:10:36 > 0:10:40People were determined to find out what was killing the fish.

0:10:40 > 0:10:42And what they discovered caused alarm.

0:10:45 > 0:10:48They found a bloodsucker

0:10:48 > 0:10:51that's been around since the time of the dinosaurs.

0:10:51 > 0:10:55A fish, albeit a very weird one, called a sea lamprey.

0:10:57 > 0:11:00So, this is a sea lamprey, it looks like an eel.

0:11:00 > 0:11:04They're not eels actually, they're their own family.

0:11:04 > 0:11:09A lamprey has a mouth that's suited to nothing better than feeding.

0:11:09 > 0:11:13It's a suction cup, so it's as strong as a suction cup.

0:11:13 > 0:11:17The mouth is ringed with sharp teeth and the middle of the mouth is a

0:11:17 > 0:11:21file-like tongue that flicks its way through the scales and skin of

0:11:21 > 0:11:23a fish, so that the lamprey is able to

0:11:23 > 0:11:25feed on the blood and body fluids of that fish.

0:11:25 > 0:11:29It'll go through about 40 pounds of fish during

0:11:29 > 0:11:33that parasitic phase, before it moves into a stream

0:11:33 > 0:11:34to spawn once and die.

0:11:34 > 0:11:38But why was a prehistoric predator suddenly inflicting its death hickey

0:11:38 > 0:11:40on the Great Lakes' fish?

0:11:45 > 0:11:48Sea lampreys are normally found here,

0:11:48 > 0:11:50down the Atlantic coast of North America.

0:11:50 > 0:11:55So, how on earth did they end up all the way inland over here?

0:11:57 > 0:12:02The Niagara Falls are an impassable natural obstacle.

0:12:02 > 0:12:05And they are the only thing stopping lampreys

0:12:05 > 0:12:06getting beyond Lake Ontario.

0:12:08 > 0:12:11Until we stepped in.

0:12:12 > 0:12:16In the 1920s, engineers opened the Welland Canal,

0:12:16 > 0:12:19linking Lake Ontario to Lake Erie.

0:12:21 > 0:12:23On the one hand, it was a great success -

0:12:23 > 0:12:28allowing ships to bypass the Niagara Falls, but on the other,

0:12:28 > 0:12:33it was a disaster, which opened the floodgates for lampreys.

0:12:36 > 0:12:39Lamprey made it past Niagara Falls in about 1920

0:12:39 > 0:12:43and made it all the way to Lake Superior by about 1939.

0:12:45 > 0:12:48Only 20 years after the new canal was opened,

0:12:48 > 0:12:53the lamprey had successfully invaded the entire Great Lakes Basin.

0:12:59 > 0:13:01It was a perfect storm for invasion.

0:13:01 > 0:13:04They had an almost unlimited food supply, because there was abundant,

0:13:04 > 0:13:07succulent, tasty fish for the lamprey in the Lakes

0:13:07 > 0:13:09and there is nothing preying upon lamprey

0:13:09 > 0:13:11or keeping the lamprey in check.

0:13:11 > 0:13:13It was a free, open buffet for the sea lamprey.

0:13:19 > 0:13:23Plenty of food, perfect spawning grounds, no natural predators.

0:13:23 > 0:13:28The lampreys had slithered their way into paradise.

0:13:28 > 0:13:30Yes! Or, no.

0:13:30 > 0:13:33You see, for the people of the Great Lakes, these things were killers.

0:13:33 > 0:13:35A menace that had to be dealt with.

0:13:35 > 0:13:39So, whilst the rest of the world were gearing up for the Cold War,

0:13:39 > 0:13:42these folks were involved in a fishy fracas.

0:13:45 > 0:13:49And to show you how bad it got - prior to the lamprey invasion,

0:13:49 > 0:13:52the harvest of fish in Lake Michigan

0:13:52 > 0:13:55and Huron was about 20 million pounds annually.

0:13:55 > 0:13:57After the lamprey invasion,

0:13:57 > 0:14:00that fell to only a few hundred thousand pounds

0:14:00 > 0:14:02and that happened over the course of a relatively

0:14:02 > 0:14:05short amount of time.

0:14:05 > 0:14:07The lampreys were guzzling fish

0:14:07 > 0:14:10faster than a sea lion at a sushi bar.

0:14:10 > 0:14:12They were that bad.

0:14:12 > 0:14:14They were taking five times the amount of fish that humans

0:14:14 > 0:14:16were harvesting.

0:14:16 > 0:14:18It was make or break time.

0:14:18 > 0:14:22They had to find a way to bring this destructive predator under control.

0:14:23 > 0:14:25So, they threw everything at it.

0:14:26 > 0:14:30Starting with barriers and traps.

0:14:30 > 0:14:33They had to prevent the lampreys reaching

0:14:33 > 0:14:35or leaving their spawning grounds.

0:14:38 > 0:14:43When the traps on their own failed, they tried adding electricity.

0:14:43 > 0:14:47Unfortunately, some of those early attempts at lamprey control

0:14:47 > 0:14:50were quite... They were abject failures, actually.

0:14:50 > 0:14:54And in fact, some of the electrical barriers were very rudimentary,

0:14:54 > 0:14:56not much different, some say, than just throwing your toaster

0:14:56 > 0:15:00in the river and zapping whatever happens to be in there.

0:15:00 > 0:15:03So, the scientists switched to chemical warfare

0:15:03 > 0:15:05and developed a weapon that

0:15:05 > 0:15:09could kill lamprey without harming any other wildlife.

0:15:13 > 0:15:17A chemical called lampricide was the biggest breakthrough in the war

0:15:17 > 0:15:19against the lampreys yet.

0:15:19 > 0:15:21But the scientists couldn't rest on their laurels.

0:15:21 > 0:15:26At any point, the lampreys could develop a resistance to it.

0:15:26 > 0:15:29So, they'd won a battle, but to win the war,

0:15:29 > 0:15:33they'd have to exploit the lampreys' natural senses.

0:15:33 > 0:15:36The sea lamprey has a very refined sense of smell. In fact,

0:15:36 > 0:15:40most of their brain is for olfactory purposes.

0:15:40 > 0:15:42We call them swimming noses, because they're, basically,

0:15:42 > 0:15:45they have a very refined sense of smell.

0:15:45 > 0:15:48The scientists found that female lampreys

0:15:48 > 0:15:50are attracted to males by smell.

0:15:52 > 0:15:55So, they isolated the chemical responsible.

0:15:55 > 0:15:57Known as a pheromone,

0:15:57 > 0:16:02it was male lamprey cologne and it drove lady lampreys wild.

0:16:06 > 0:16:09This pheromone could be used to hoodwink the females

0:16:09 > 0:16:13into going into traps on the promise of a bit of hanky-panky.

0:16:13 > 0:16:16But there was even better news.

0:16:16 > 0:16:20You see, the scientist had managed to isolate the polar opposite

0:16:20 > 0:16:22to this attractant.

0:16:22 > 0:16:24A naturally occurring chemical called a necromone,

0:16:24 > 0:16:27a sort of eau de death,

0:16:27 > 0:16:30and the lampreys will do absolutely everything

0:16:30 > 0:16:32to avoid this death smell.

0:16:36 > 0:16:38Using these natural chemicals,

0:16:38 > 0:16:41scientists hope to create a push and pull effect,

0:16:41 > 0:16:44using necromones to push lamprey away from places

0:16:44 > 0:16:47they don't want them to be, like streams,

0:16:47 > 0:16:53with great spawning habitat, and pheromones to pull them into traps.

0:16:53 > 0:16:56By turning their own senses against them,

0:16:56 > 0:16:59scientists finally had this slippery customer under control.

0:17:01 > 0:17:05We've gone from about two million lamprey in the Great Lakes

0:17:05 > 0:17:07to only a few hundred thousand,

0:17:07 > 0:17:10and that's a significant drop in the lamprey numbers.

0:17:10 > 0:17:11It certainly is.

0:17:11 > 0:17:14But you have to give respect where it's due.

0:17:14 > 0:17:15This brilliant parasite,

0:17:15 > 0:17:19with its efficient if disturbing means of survival,

0:17:19 > 0:17:22has been giving human beings the run-around

0:17:22 > 0:17:24for almost 100 years.

0:17:24 > 0:17:29Since 1957, we've probably spent about 800 million or 900 million

0:17:29 > 0:17:31to control lamprey. But contrast that to the fact

0:17:31 > 0:17:35that the Great Lakes' fishery is worth 7 billion every year to

0:17:35 > 0:17:38the people of the US and Canada, and you can see it's a small price

0:17:38 > 0:17:40that we pay to have the fishery that we have.

0:17:40 > 0:17:43Without the sea lamprey control programme,

0:17:43 > 0:17:46we have no fishery to speak of.

0:17:51 > 0:17:56Those lampreys almost ruined the Great Lakes fishery.

0:17:56 > 0:17:59I've got to say, they got us out of a bit of a jam.

0:17:59 > 0:18:02You see, there's a long-held tradition in the UK

0:18:02 > 0:18:04that on the occasion of their jubilee,

0:18:04 > 0:18:07the reigning monarch is given a lamprey pie,

0:18:07 > 0:18:12except that here, lampreys are an endangered animal.

0:18:12 > 0:18:16But thankfully, the Canadians sent some over.

0:18:16 > 0:18:19And on the 60th anniversary of her reaching the throne,

0:18:19 > 0:18:23Queen Elizabeth was thus presented with a lamprey pie.

0:18:26 > 0:18:29History does not recount whether she ate it or not.

0:18:32 > 0:18:37Our next event takes place in the marshlands of the Negev desert

0:18:37 > 0:18:40in Israel, where a battle of a different kind is raging.

0:18:43 > 0:18:48Something here has an unhealthy appetite for toads and frogs -

0:18:48 > 0:18:50and not just their legs.

0:18:53 > 0:18:56Half-eaten amphibians are cropping up all over the place.

0:18:58 > 0:19:01But what's causing the slaughter?

0:19:01 > 0:19:07Well, a bizarre clue was discovered by a team of entomologists in 2005.

0:19:09 > 0:19:13What we found first were several toad specimens

0:19:13 > 0:19:16that were carrying larvae on their bodies.

0:19:16 > 0:19:19And because no-one had seen this before,

0:19:19 > 0:19:22at least in Israel,

0:19:22 > 0:19:25we didn't know what they are, so we took them to the lab.

0:19:30 > 0:19:34At first, we thought that this was completely incidental,

0:19:34 > 0:19:41that they were just larvae accidentally attached to the toads

0:19:41 > 0:19:46and we were sure that they would just drop off after a few hours.

0:19:47 > 0:19:51Gil and his team decided to keep the amphibians under observation,

0:19:51 > 0:19:53and they didn't have to wait long

0:19:53 > 0:19:55before they made a macabre discovery.

0:20:00 > 0:20:04The researchers couldn't believe their eyes.

0:20:04 > 0:20:07The larvae weren't just hitching a ride,

0:20:07 > 0:20:10they were attacking their amphibian hosts.

0:20:12 > 0:20:16Only after we kept the toads and the larvae in the lab for a while,

0:20:16 > 0:20:18we noticed that the larvae kill the frogs.

0:20:19 > 0:20:24Frog after frog fell foul to their surprising assassin.

0:20:24 > 0:20:27It was clear that this was no accident of fate.

0:20:28 > 0:20:32When we thought that they are actually feeding on the toads,

0:20:32 > 0:20:34and they just didn't drop off, we said,

0:20:34 > 0:20:38"OK, this is something interesting. We should check it out."

0:20:40 > 0:20:42Things just didn't add up.

0:20:45 > 0:20:49Anything that's small and moving is normally fair game to an amphibian.

0:20:55 > 0:20:59The beetle larvae should be an easy meal,

0:20:59 > 0:21:02so how has this grisly grub turned the tables?

0:21:04 > 0:21:07Gil and his team had to find out.

0:21:09 > 0:21:13So, we went back to the field to collect more adults and more frogs

0:21:13 > 0:21:17carrying larvae to bring them back into the lab.

0:21:17 > 0:21:20Eventually, the larvae will complete their life cycle

0:21:20 > 0:21:23or complete the developmental stage.

0:21:23 > 0:21:26They will pupate and become beetles, and we wanted to know

0:21:26 > 0:21:28what these beetles were.

0:21:29 > 0:21:32So, would this bizarre larvae emerge from its pupae

0:21:32 > 0:21:37as a grotesque adult beetle? Well, actually, no.

0:21:37 > 0:21:40It hatches out as a rather plain ground beetle.

0:21:40 > 0:21:42It's always the quiet ones, isn't it?

0:21:44 > 0:21:49This unassuming arthropod goes by the name of epomis circumscriptus.

0:21:52 > 0:21:55But why had such ordinary-looking beetles

0:21:55 > 0:21:57produced such diabolical babies?

0:21:59 > 0:22:01Well, Gil has a theory.

0:22:02 > 0:22:09We think that it evolved from some sort of counterattack,

0:22:09 > 0:22:13as some sort of defence.

0:22:13 > 0:22:15And throughout time,

0:22:15 > 0:22:21these larvae learned to utilise amphibians as food

0:22:21 > 0:22:23and started feeding on them and eventually,

0:22:23 > 0:22:27they just stopped feeding on everything else

0:22:27 > 0:22:30and fed exclusively on amphibians.

0:22:32 > 0:22:36The larvae weren't just fighting back any more,

0:22:36 > 0:22:39they were actively inviting the attack,

0:22:39 > 0:22:42and in a truly remarkable way.

0:22:44 > 0:22:48It uses very minute behaviour,

0:22:48 > 0:22:51very minute movements to lure amphibians towards it.

0:22:51 > 0:22:56It moves its antennae and mandibles in a repeated cycle

0:22:56 > 0:23:01that entices the amphibians to approach and even to attack.

0:23:01 > 0:23:03By acting like a tasty snack,

0:23:03 > 0:23:05the epomis larvae had managed to turn

0:23:05 > 0:23:09the amphibian's own hunting instincts against them.

0:23:11 > 0:23:15And then it uses its double-hook mandibles to attach

0:23:15 > 0:23:19to the amphibian's body, to lock onto the skin.

0:23:19 > 0:23:20Once it is attached,

0:23:20 > 0:23:23it starts feeding on the amphibian's body fluids.

0:23:23 > 0:23:29And what's absolutely extraordinary is that a single greedy grub

0:23:29 > 0:23:33can chomp its way through nine frogs before it is ready to pupate.

0:23:36 > 0:23:40A dead frog looks like...

0:23:40 > 0:23:42Well, it doesn't look like a frog at all.

0:23:42 > 0:23:45It looks like a pile of bones,

0:23:45 > 0:23:48like someone just ate all the fleshy parts of the frog, the eyes,

0:23:48 > 0:23:53some of the skin, and you get this almost perfect skeleton of bones.

0:23:53 > 0:23:56Sometimes it's a complete skeleton, sometimes it's just a pile of bones,

0:23:56 > 0:23:58with no shape at all.

0:24:04 > 0:24:08It's easy for us to see the frogs and toads as the victims here.

0:24:08 > 0:24:10But you've got to remember that

0:24:10 > 0:24:14during the course of their lifetimes, they eat thousands

0:24:14 > 0:24:17of insects without ever thinking about it.

0:24:17 > 0:24:19And the epomis beetle is the only species

0:24:19 > 0:24:25we've seen that completely reverses the predator prey role.

0:24:25 > 0:24:29So, it's unique and extremely weird.

0:24:33 > 0:24:38For our next story, we head north to the Arctic Ocean,

0:24:38 > 0:24:41where there's weirdness in abundance.

0:24:46 > 0:24:51Living amongst the sea ice are some of our planet's strangest animals.

0:24:54 > 0:24:58And perhaps oddest of all is the Greenland shark.

0:25:01 > 0:25:03At up to six metres long,

0:25:03 > 0:25:07Greenland sharks rival great whites in terms of size.

0:25:07 > 0:25:11But in comparison, very little is known about them.

0:25:12 > 0:25:15They live at amazing depths,

0:25:15 > 0:25:18often below the level that light can penetrate.

0:25:20 > 0:25:22So, not only are they hard to find,

0:25:22 > 0:25:25it's also a dangerous place to study them.

0:25:27 > 0:25:31But sometimes, these sharks are accidentally caught by fishermen.

0:25:33 > 0:25:35So, a team of marine biologists

0:25:35 > 0:25:39decided to make the most of a bad situation.

0:25:42 > 0:25:46In 2010, they set off in Denmark to investigate.

0:25:47 > 0:25:49Over the next three years,

0:25:49 > 0:25:53they would study every shark that they could get their hands on.

0:26:05 > 0:26:10Samples were frozen, so they could be examined later, back in the lab.

0:26:12 > 0:26:14The team didn't know it yet,

0:26:14 > 0:26:18but one of their discoveries would change the face of biology.

0:26:23 > 0:26:28No-one knew how long these remarkable animals live.

0:26:29 > 0:26:33Because sharks have a skeleton made of cartilage rather than bone,

0:26:33 > 0:26:36the usual method of carbon dating doesn't work.

0:26:38 > 0:26:41The biologists had to find another way of ageing them

0:26:41 > 0:26:45and they found the answer they were looking for in a remarkable place.

0:26:49 > 0:26:55The shark's eye contains proteins formed when it was an embryo.

0:26:55 > 0:26:58These can be carbon dated,

0:26:58 > 0:27:03so a sample was sent back to the lab and this was the chance to finally

0:27:03 > 0:27:05age these mysterious animals.

0:27:08 > 0:27:10When the results were analysed,

0:27:10 > 0:27:16the oldest shark was shown to be somewhere between 272

0:27:16 > 0:27:20and 512-years-old.

0:27:20 > 0:27:22Now, even if we plumped for somewhere

0:27:22 > 0:27:23in the middle of that range,

0:27:23 > 0:27:26that means there could be a shark living today

0:27:26 > 0:27:29that was born on the same day as Isaac Newton,

0:27:29 > 0:27:32that lived through the Great Fire of London,

0:27:32 > 0:27:34the English Civil War.

0:27:34 > 0:27:37There could be a shark out there that remembers

0:27:37 > 0:27:41England winning the World Cup!

0:27:41 > 0:27:45A shark hundreds of years old is extraordinary in itself.

0:27:45 > 0:27:49But this miraculous life-span is even more impressive

0:27:49 > 0:27:52when you realise what these deep sea survivors are up against.

0:27:56 > 0:28:00I would say they're living on the edge the whole time,

0:28:00 > 0:28:04in terms of tolerating the extremes of the cold,

0:28:04 > 0:28:08the extremes of pressure that they inhabit, and also,

0:28:08 > 0:28:11actually finding the food that they need

0:28:11 > 0:28:14just for their general life and routines.

0:28:18 > 0:28:22So, it's literally a life of searching for food

0:28:22 > 0:28:26in a very hostile environment.

0:28:26 > 0:28:29Surviving in the cold and dark is impressive enough,

0:28:29 > 0:28:32but there's another bizarre twist to this tale.

0:28:35 > 0:28:38If you're searching for food in an environment like this,

0:28:38 > 0:28:41it would pay to have pretty good eyesight and I've got to tell you

0:28:41 > 0:28:44that when Greenland sharks are born they do have

0:28:44 > 0:28:47a perfectly respectable set of peepers.

0:28:47 > 0:28:51In fact, they've got larger eyes than most other species of shark,

0:28:51 > 0:28:56but as they grow up, something very weird happens.

0:29:00 > 0:29:04One of the amazing points of the Greenland shark,

0:29:04 > 0:29:07a very unique characteristic that we don't see

0:29:07 > 0:29:08in any other shark species,

0:29:08 > 0:29:14is a parasitic copepod that is embedded into the eyes

0:29:14 > 0:29:18of this particular species, and this is extremely common,

0:29:18 > 0:29:21particularly in the mid to high Arctic.

0:29:21 > 0:29:24All of the Greenland sharks that you'll encounter

0:29:24 > 0:29:30have this particular parasite that's embedded into the eye.

0:29:30 > 0:29:32Copepods are tiny crustaceans.

0:29:32 > 0:29:37Most are drifters and spend their lives hanging out in the plankton.

0:29:37 > 0:29:42But one, called Ommatokoita, has decided to settle down

0:29:42 > 0:29:45on the Greenland shark's eyeball.

0:29:46 > 0:29:51The parasitic copepod actually anchors right inside

0:29:51 > 0:29:54the central part of the eye.

0:29:54 > 0:29:58It's got an anchor system, which is called a bulbar, that locks into

0:29:58 > 0:30:04the eye, and the thought is that the parasite actually feeds off

0:30:04 > 0:30:06the surface of the eye itself.

0:30:07 > 0:30:12So, how does a blind shark survive in these Arctic conditions

0:30:12 > 0:30:15for hundreds of years?

0:30:15 > 0:30:17Well, it appears that it might benefit

0:30:17 > 0:30:19from the misfortune of others.

0:30:21 > 0:30:26We assume the Greenland shark is a scavenger and it is thought that

0:30:26 > 0:30:29it obtains most of the larger prey items from dead animals

0:30:29 > 0:30:32that have fallen to the sea floor.

0:30:32 > 0:30:36And therefore, if you're going to feed in that particular way,

0:30:36 > 0:30:38you obviously need an extraordinarily good

0:30:38 > 0:30:41sense of smell to be able to navigate around

0:30:41 > 0:30:44and locate those food falls.

0:30:44 > 0:30:47Although the Greenland shark has large eyes and they're potentially

0:30:47 > 0:30:51adapted in some way for these very low light levels,

0:30:51 > 0:30:56I think that the Greenland shark is not majorly dependent

0:30:56 > 0:30:59on vision as a cue to locate prey.

0:31:07 > 0:31:11Ladies and gentlemen, I give you the Greenland shark.

0:31:11 > 0:31:14What an animal. What an animal!

0:31:14 > 0:31:18Not only can it lose its vision and live on for hundreds of years,

0:31:18 > 0:31:24it's probably the oldest living vertebrate on planet Earth.

0:31:24 > 0:31:28It has to be nature's greatest survivor.

0:31:32 > 0:31:35We've seen how animals can adapt and survive,

0:31:35 > 0:31:39even in the most extreme situations.

0:31:39 > 0:31:43But next up, we meet a man who has to cope

0:31:43 > 0:31:46with his own rather surreal senses.

0:31:49 > 0:31:53Englishman James Wannerton doesn't just see the world differently

0:31:53 > 0:31:55to most of us, he tastes it.

0:32:00 > 0:32:05What happens is I get one of my senses stimulated, my hearing,

0:32:05 > 0:32:08and that immediately gets translated into a taste for me.

0:32:12 > 0:32:15It's a real mouth thing as well, it's not, not an association.

0:32:15 > 0:32:19It's actually a mouth thing. It's as if I'm actually eating something.

0:32:19 > 0:32:22Yes, James can taste words.

0:32:22 > 0:32:26And what's more, he's had this peculiar ability since childhood.

0:32:29 > 0:32:34I used to go on the tube train with my mum and I used to read off

0:32:34 > 0:32:36the names of the stations as we passed through them,

0:32:36 > 0:32:38and each of the stations had

0:32:38 > 0:32:41a unique and distinct taste and texture.

0:32:41 > 0:32:46We used to travel on the Central line, which was my tastiest line,

0:32:46 > 0:32:48it was lovely. Not all these tastes are nice,

0:32:48 > 0:32:50there were a few stations that were pretty horrible.

0:32:50 > 0:32:53Bond Street is one. It's got the taste and texture of

0:32:53 > 0:32:55something similar to hair spray.

0:32:55 > 0:32:57Tangy.

0:32:58 > 0:33:00It's horrible.

0:33:01 > 0:33:04Most people's senses work independently,

0:33:04 > 0:33:08so why is James' sense of taste triggered by the sound of a word?

0:33:10 > 0:33:14Could it be something to do with the one organ that has to interpret

0:33:14 > 0:33:18everything that we see, hear, taste, touch and smell?

0:33:20 > 0:33:23Imagine that this is my brain.

0:33:23 > 0:33:28It allows me to get around and make sense of the world and each part of

0:33:28 > 0:33:31that brain is ascribed a specific task

0:33:31 > 0:33:34and you need all of those parts for it to function properly.

0:33:35 > 0:33:39Let's imagine that the lemon is damaged in an accident,

0:33:39 > 0:33:43then I may not be able to recognise myself in a mirror.

0:33:43 > 0:33:46And if the apple becomes diseased,

0:33:46 > 0:33:50I then think that my left hand belongs to someone else.

0:33:50 > 0:33:53Now these are not amusing anecdotes,

0:33:53 > 0:33:55these are neurological conditions

0:33:55 > 0:34:00that have been recorded by doctors and what they tell us is that when

0:34:00 > 0:34:04the brain is damaged, things get taken away.

0:34:04 > 0:34:08But in James' case it's not about being taken away,

0:34:08 > 0:34:12it's that he's got extra perceptions.

0:34:12 > 0:34:16So, is it a case that James' brain, effectively,

0:34:16 > 0:34:18has more fruit not less?

0:34:21 > 0:34:25To the best of our knowledge, there seemed to be perhaps extra

0:34:25 > 0:34:29or strengthened connections between the area of his brain that processes

0:34:29 > 0:34:32words and the area that processes tastes.

0:34:36 > 0:34:41And there are neurons firing from the word portion of his brain to

0:34:41 > 0:34:42the taste portion of his brain

0:34:42 > 0:34:46and that causes him to have this extra perception.

0:34:46 > 0:34:49So, James' brain doesn't have extra fruit,

0:34:49 > 0:34:54just extra connections between the fruit and this allows some of

0:34:54 > 0:34:56his senses to talk to each other.

0:34:56 > 0:34:59It's like an eye dropper of taste, you know, just drops.

0:34:59 > 0:35:01Just drip-drops, one after the other...

0:35:01 > 0:35:04- HE IMITATES EYE DROPS FALLING - ..for every single sound I hear.

0:35:04 > 0:35:11This fantastic neurological phenomenon is called synaesthesia.

0:35:11 > 0:35:14The vast majority of the synaesthetic tastes

0:35:14 > 0:35:19that I experience are from childhood. A lot of them are sweets,

0:35:19 > 0:35:24things like wine gums and sweets you can't buy any more.

0:35:24 > 0:35:26So, does James' childhood offer a clue to where

0:35:26 > 0:35:30his curious condition came from?

0:35:32 > 0:35:37So, the general idea is that perhaps synaesthetes have some

0:35:37 > 0:35:43genetic difference that causes either extra connections

0:35:43 > 0:35:45or a lack of pruning of connections.

0:35:45 > 0:35:50So, when we're born, we have lots of neural connections

0:35:50 > 0:35:54and throughout time, those neural connections get pruned down

0:35:54 > 0:35:57to the ones that are meaningful for us.

0:35:58 > 0:36:00In every newborn baby's brain,

0:36:00 > 0:36:03represented by this bunch of bananas,

0:36:03 > 0:36:06the senses are better connected.

0:36:06 > 0:36:10But we don't need all of these connections to understand the world,

0:36:10 > 0:36:15so gradually, one by one, they are severed.

0:36:15 > 0:36:18The difference, however, with James' brain is that

0:36:18 > 0:36:20one of these connections remains intact,

0:36:20 > 0:36:23the one between the piece that processes words

0:36:23 > 0:36:27and the piece that processes tastes.

0:36:27 > 0:36:29And that is mind-boggling.

0:36:31 > 0:36:36So, what if some brilliant brain surgeon discovered a way of snipping

0:36:36 > 0:36:40James' extra neural connections now,

0:36:40 > 0:36:44freeing him from these strange synaesthetic sensations forever?

0:36:44 > 0:36:47Would he do it?

0:36:47 > 0:36:48I couldn't imagine life without it.

0:36:48 > 0:36:51And I think most synaesthetes would say the same.

0:36:53 > 0:36:57Fantastic. And although this might read as faulty wiring,

0:36:57 > 0:37:01in my opinion, this is as close as a human can come

0:37:01 > 0:37:04to having a proper superpower,

0:37:04 > 0:37:09so I couldn't resist asking James what my name tasted like.

0:37:09 > 0:37:10Do you know what he said?

0:37:12 > 0:37:13Soggy crisps.

0:37:13 > 0:37:15Soggy crisps!

0:37:15 > 0:37:17So much for the superpower.

0:37:21 > 0:37:23For our next sensational story,

0:37:23 > 0:37:27we head to the coast of south-west Australia.

0:37:27 > 0:37:32This is a favourite spot for shark lovers from all over the world.

0:37:32 > 0:37:36And there is no bigger draw than a great white.

0:37:36 > 0:37:40But the traditional method of baiting them in with a bag of fish

0:37:40 > 0:37:44body parts can put sharks in a bit of a frenzy.

0:37:45 > 0:37:48And with water sports enthusiasts all along the coast,

0:37:48 > 0:37:52the last thing the authorities want to do here is put sharks

0:37:52 > 0:37:54in any kind of frenzy.

0:37:54 > 0:37:58So, when they stopped issuing licences to bait sharks,

0:37:58 > 0:38:02one tour operator had to get creative.

0:38:02 > 0:38:04Necessity is the mother of invention.

0:38:04 > 0:38:06When we started shark cage diving,

0:38:06 > 0:38:10initially we weren't allowed to use blood and bait, so we looked for

0:38:10 > 0:38:15alternatives around other senses that could attract sharks

0:38:15 > 0:38:20and music or acoustics was just an obvious thing to try.

0:38:21 > 0:38:24We may think it's rather quiet underwater,

0:38:24 > 0:38:28but in fact lots of marine animals use sound to communicate.

0:38:29 > 0:38:31But using music to attract sharks,

0:38:31 > 0:38:33where on earth you begin?

0:38:39 > 0:38:43So, when we first trialled this

0:38:43 > 0:38:47we just, we grabbed the speaker off one of my mates and we went down,

0:38:47 > 0:38:49we put it in the water, connected it to the iPod,

0:38:49 > 0:38:52it was my iPod and we just started at A.

0:38:52 > 0:38:55Now, I'm a country Aussie kid,

0:38:55 > 0:38:57I only have one type of music and it's usually Aussie rock,

0:38:57 > 0:39:00so the first album on the list was AC/DC - Back In Black.

0:39:00 > 0:39:03When we turned it on, we had sharks within a minute

0:39:03 > 0:39:05and they hung around for 20 minutes.

0:39:05 > 0:39:08And the sharks were coming up and just rubbing their face on

0:39:08 > 0:39:12the speaker and we were just like, "This is the coolest thing ever."

0:39:15 > 0:39:17Come on, come on.

0:39:17 > 0:39:21Even if we do away with the stereotypes of the long greasy hair,

0:39:21 > 0:39:24the patch-covered denim jackets and the head-banging,

0:39:24 > 0:39:28I just can't see sharks as heavy metal fans.

0:39:28 > 0:39:31So, was Matt's experiment a bit of a freak, a one-off,

0:39:31 > 0:39:36or do these animals truly have an appreciation of music?

0:39:36 > 0:39:37He was about to find out.

0:39:41 > 0:39:44Within days of the story hitting social media,

0:39:44 > 0:39:48Matt was inundated with requests to try other music.

0:39:49 > 0:39:52We started going through the playlist and what we saw is that it

0:39:52 > 0:39:54wasn't just AC/DC that attracts sharks,

0:39:54 > 0:39:55there were other songs as well.

0:39:55 > 0:39:59We got to one particular shark, Bernadette I think her name was,

0:39:59 > 0:40:03that every time we played Talking Heads - Sax And Violins

0:40:03 > 0:40:07she would breach out of the water.

0:40:07 > 0:40:10The only time we'd see this shark is when that song was playing and we

0:40:10 > 0:40:14started to think that maybe sharks had individual preferences.

0:40:14 > 0:40:18Matt now had proof that his experiment worked.

0:40:18 > 0:40:21The one big question remaining was why?

0:40:22 > 0:40:24A lot of species of sharks, like white sharks,

0:40:24 > 0:40:28that live in open ocean, or in the pelagic environment,

0:40:28 > 0:40:33because of the low rate of encounter of prey, potential prey,

0:40:33 > 0:40:37you would expect them to react and to investigate any kind of stimulus.

0:40:37 > 0:40:41So, if there is a sound or a smell that they encounter,

0:40:41 > 0:40:43because they are curious animals,

0:40:43 > 0:40:47they are likely to go and check out what is producing that sound,

0:40:47 > 0:40:49as it could potentially be a prey item.

0:40:52 > 0:40:55The sharks appeared to enjoy a wide musical repertoire,

0:40:55 > 0:41:00but the tracks that worked best had something in common -

0:41:00 > 0:41:03a driving bassline.

0:41:06 > 0:41:09Low-frequency sounds travel a long way underwater

0:41:09 > 0:41:12and it's just possible that sharks can mistake them

0:41:12 > 0:41:14for the death throes of an injured fish.

0:41:16 > 0:41:21That's because they don't just hear sound, they feel it.

0:41:23 > 0:41:24You see, in sharks,

0:41:24 > 0:41:28hearing and vibration detection are fundamentally linked.

0:41:28 > 0:41:35A fluid-filled tube call the lateral line extends along each flank.

0:41:38 > 0:41:41This tube is in direct contact with the water,

0:41:41 > 0:41:43via tiny holes in the skin.

0:41:46 > 0:41:49When sound causes the water to vibrate,

0:41:49 > 0:41:52it moves tiny hairs inside the lateral line

0:41:52 > 0:41:56and this tells the shark which direction it came from.

0:41:59 > 0:42:02Rock and roll, it does have the largest success probably,

0:42:02 > 0:42:06because of the lower down frequency vibrations, the bass beat.

0:42:06 > 0:42:07And even the distortion.

0:42:07 > 0:42:11It might have something to do with replication of a feeding behaviour,

0:42:11 > 0:42:16we don't know, but when a shark comes back to the same song,

0:42:16 > 0:42:19time after time, knowing that there's no food available,

0:42:19 > 0:42:24what is the attraction? Maybe they just think it's cool.

0:42:24 > 0:42:26Sitting underwater,

0:42:26 > 0:42:29listening to your favourite song by Metallica and having a shark just

0:42:29 > 0:42:32cruise past, looks like he's rocking out to the beat,

0:42:32 > 0:42:35letting his hair down and just kicking back with the tunes.

0:42:42 > 0:42:44Shark music.

0:42:44 > 0:42:47I absolutely love it, because it gives us the opportunity

0:42:47 > 0:42:52to redefine the great white as something which isn't a purely

0:42:52 > 0:42:56psychopathic fish and it gives people the ability to engage with

0:42:56 > 0:43:00this animal in a relatively nonintrusive way.

0:43:00 > 0:43:02It's genius. Utter genius.

0:43:02 > 0:43:06There's just one thing, I so wish they'd been into The Ramones.

0:43:10 > 0:43:13From a man with a finger-licking lexicon...

0:43:13 > 0:43:15Tastes horrible.

0:43:15 > 0:43:19..to a shark with an appetite for music,

0:43:19 > 0:43:21we've seen how the senses can perplex

0:43:21 > 0:43:23and please us in equal measure.

0:43:26 > 0:43:33From frogs to fish to beetles to humans, weirdness has no boundaries.

0:43:33 > 0:43:36It comes in all shapes and sizes.