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We live in a very weird world. | 0:00:02 | 0:00:05 | |
And the more we discover about our planet, the stranger it gets. | 0:00:09 | 0:00:13 | |
Every day, new stories reach us, stories that surprise us... | 0:00:14 | 0:00:20 | |
What is that? | 0:00:20 | 0:00:22 | |
'..shock us...' | 0:00:22 | 0:00:23 | |
-Whoa! That is so cool. -Oh, my God! | 0:00:23 | 0:00:25 | |
..and sometimes, even scare us. | 0:00:25 | 0:00:29 | |
Argh! | 0:00:29 | 0:00:30 | |
Oh, my God. | 0:00:30 | 0:00:32 | |
We've scoured the globe to bring you the most curious creatures... | 0:00:32 | 0:00:37 | |
..the most extraordinary people... | 0:00:38 | 0:00:40 | |
I can stick almost anything to my skin without no glue. | 0:00:40 | 0:00:44 | |
..and the most bizarre behaviour. | 0:00:44 | 0:00:46 | |
Using eyewitness accounts and expert opinion to explore a weird world | 0:00:49 | 0:00:55 | |
of unexplained underwater blobs, | 0:00:55 | 0:00:59 | |
flying goats | 0:00:59 | 0:01:02 | |
and glow-in-the-dark fish. | 0:01:02 | 0:01:04 | |
We examine the evidence, test the theories, | 0:01:06 | 0:01:12 | |
to work out what on earth is going on. | 0:01:12 | 0:01:15 | |
In this episode - discover what made a monster wave | 0:01:34 | 0:01:37 | |
appear out of nowhere. | 0:01:37 | 0:01:40 | |
Oh, she's going. | 0:01:40 | 0:01:43 | |
How vampires suddenly appeared in America's Great Lakes. | 0:01:43 | 0:01:48 | |
And whether great white sharks really enjoy a bit of head-banging. | 0:01:48 | 0:01:53 | |
And for our first dip into the world of weirdness, | 0:01:56 | 0:01:59 | |
we head to the seaside. | 0:01:59 | 0:02:01 | |
Australia, 2015. | 0:02:04 | 0:02:07 | |
A group of friends decide to pack their swimming gear and head to | 0:02:07 | 0:02:12 | |
some rock pools on the picturesque coast 50km south of Sydney. | 0:02:12 | 0:02:16 | |
It was quite a nice day, probably high 20s, very clear, | 0:02:17 | 0:02:22 | |
sunny, warm day. | 0:02:22 | 0:02:24 | |
Nothing out of the ordinary, so it wasn't wild weather or anything | 0:02:27 | 0:02:30 | |
like that, so it was quite a nice day | 0:02:30 | 0:02:32 | |
to go for a walk and then a swim. | 0:02:32 | 0:02:34 | |
Sun, warm seas and calm, crystal clear water. | 0:02:34 | 0:02:38 | |
What could possibly go wrong? | 0:02:38 | 0:02:40 | |
We put our things down and decided that we'd go in one at a time, | 0:02:42 | 0:02:46 | |
so Mika went in first. | 0:02:46 | 0:02:49 | |
We were watching, Alex and I were watching him in the distance. | 0:02:51 | 0:02:54 | |
And then, | 0:02:54 | 0:02:56 | |
all of a sudden, we saw a really, really big wave | 0:02:56 | 0:02:59 | |
coming from the background... | 0:02:59 | 0:03:02 | |
Oh, get out! | 0:03:02 | 0:03:04 | |
..which completely shocked us and we were standing there | 0:03:04 | 0:03:07 | |
screaming out to Mika. | 0:03:07 | 0:03:08 | |
Before we knew it, | 0:03:11 | 0:03:13 | |
he and countless other people were being dragged along the rocks. | 0:03:13 | 0:03:19 | |
I have never seen anything like that first-hand and the force of it... | 0:03:19 | 0:03:25 | |
The water reached us and we were metres and metres inland. | 0:03:25 | 0:03:28 | |
I'd say it was probably two or three times higher than what I would have | 0:03:29 | 0:03:34 | |
considered a big wave previously. | 0:03:34 | 0:03:37 | |
The wave had taken everyone by surprise. | 0:03:37 | 0:03:40 | |
And as the injured clambered their way back to the shore, | 0:03:40 | 0:03:44 | |
the questions started flying. | 0:03:44 | 0:03:46 | |
Everyone wanted to know where this freak wave had come from. | 0:03:47 | 0:03:52 | |
And how could something like this appear from nowhere? | 0:03:52 | 0:03:55 | |
Most of the waves that we see are either caused by swell or by wind | 0:04:01 | 0:04:05 | |
blowing on the surface of the oceans. | 0:04:05 | 0:04:08 | |
It's a bit like when I blow on this water, making the ripples. | 0:04:08 | 0:04:11 | |
And of course, the stronger the wind, the bigger the waves. | 0:04:14 | 0:04:17 | |
But here's the weird thing - | 0:04:20 | 0:04:22 | |
on that day that Lisa and her friends | 0:04:22 | 0:04:24 | |
decided to take a dip in the rock pools, there was no wind. | 0:04:24 | 0:04:29 | |
It was perfectly calm. | 0:04:29 | 0:04:31 | |
And weather can't change on a whim. | 0:04:31 | 0:04:34 | |
On a calm day, all the waves would be small. | 0:04:36 | 0:04:39 | |
And on a windy day, all the waves would be big. | 0:04:41 | 0:04:44 | |
Not just one of them. | 0:04:44 | 0:04:47 | |
So, if wind alone can't explain a single giant wave, | 0:04:47 | 0:04:51 | |
did the blame lie with another force of nature altogether? | 0:04:51 | 0:04:55 | |
When earthquakes happen near or under the sea, | 0:05:00 | 0:05:03 | |
it triggers the mother of all monster waves - called a tsunami. | 0:05:03 | 0:05:07 | |
In deep water, they're almost imperceptible. | 0:05:11 | 0:05:14 | |
But a tsunami can cross entire oceans | 0:05:14 | 0:05:17 | |
at speeds of up to 600mph. | 0:05:17 | 0:05:20 | |
When they hit the shore, they slow down, | 0:05:22 | 0:05:25 | |
allowing the fast-moving water behind to catch up and in this way, | 0:05:25 | 0:05:30 | |
a huge wave can appear out of the blue. | 0:05:30 | 0:05:33 | |
So, was this wave a tsunami? | 0:05:39 | 0:05:41 | |
Well, no, it wasn't. | 0:05:41 | 0:05:43 | |
You see, tsunamis are typically formed by seismic activity. | 0:05:43 | 0:05:46 | |
They involve multiple waves and affect many miles of coastline. | 0:05:46 | 0:05:51 | |
This wave was altogether different. | 0:05:51 | 0:05:54 | |
It only affected a tiny part of the coast | 0:05:54 | 0:05:56 | |
and it came and went very quickly. | 0:05:56 | 0:05:58 | |
So, was it an anomaly, just a freak? | 0:05:58 | 0:06:01 | |
Is that possible? | 0:06:01 | 0:06:03 | |
Rogue waves, they're also called freak waves, extreme waves, | 0:06:04 | 0:06:08 | |
giant waves. There's lots of different terminology for them, | 0:06:08 | 0:06:11 | |
and essentially, they are waves that appear within a sea state | 0:06:11 | 0:06:14 | |
unexpectedly, substantially taller than any of the surrounding waves. | 0:06:14 | 0:06:18 | |
They are quite hard to predict. | 0:06:22 | 0:06:23 | |
Rogue waves do quite often appear from nowhere. | 0:06:23 | 0:06:26 | |
There's different causes that can make them appear, | 0:06:26 | 0:06:29 | |
so they can occur in any sea state, essentially. | 0:06:29 | 0:06:31 | |
So, the wave at the rock pools wasn't unique. | 0:06:33 | 0:06:36 | |
Giant waves can appear anywhere. | 0:06:36 | 0:06:39 | |
Understanding how could help prevent a disaster, but then, | 0:06:39 | 0:06:43 | |
understanding anything called a rogue or a freak is complicated. | 0:06:43 | 0:06:48 | |
Hmm, yes. | 0:06:52 | 0:06:53 | |
But why is it so complicated? | 0:06:53 | 0:06:56 | |
Well, firstly, it's because we are dealing with a liquid, | 0:06:56 | 0:07:00 | |
and when you apply a force to a liquid, it changes shape, | 0:07:00 | 0:07:04 | |
just like when I drop this marble in here. | 0:07:04 | 0:07:06 | |
And at the point of the force touching the liquid, | 0:07:06 | 0:07:09 | |
you can see the shape changing as those ripples radiate away. | 0:07:09 | 0:07:13 | |
But how about if I apply multiple forces at the same time? | 0:07:13 | 0:07:17 | |
Then what we've got is, effectively, chaos, | 0:07:23 | 0:07:27 | |
with the ripples radiating from each one of those marbles, | 0:07:27 | 0:07:31 | |
but also what we have is an enhanced probability that some | 0:07:31 | 0:07:35 | |
of those ripples will meet... | 0:07:35 | 0:07:36 | |
..to form waves, which are double the height of his single ripple. | 0:07:41 | 0:07:45 | |
And basically, that's how we get rogue waves. | 0:07:45 | 0:07:49 | |
Only the world isn't a fish tank. | 0:07:52 | 0:07:55 | |
Our oceans are massive and cover 70% of the planet. | 0:07:55 | 0:07:59 | |
Instead of lots of marbles, they have storms, | 0:08:02 | 0:08:05 | |
all happening independently and separated by vast distances. | 0:08:05 | 0:08:09 | |
Each storm creates waves that can travel for miles. | 0:08:13 | 0:08:16 | |
When two of these waves meet, they can form a bigger wave, | 0:08:19 | 0:08:22 | |
but there's more. | 0:08:22 | 0:08:24 | |
Surging currents and an undulating sea floor also play a part. | 0:08:26 | 0:08:31 | |
When all of these elements come together... | 0:08:32 | 0:08:35 | |
..a rogue wave can form, | 0:08:39 | 0:08:41 | |
and that's what happened at the rock pools that day. | 0:08:41 | 0:08:45 | |
Scientists know what ingredients are needed to make a rogue wave, | 0:08:49 | 0:08:53 | |
but they just can't yet predict them. | 0:08:53 | 0:08:55 | |
To work out the recipe, they need to analyse vast amounts of data, | 0:08:57 | 0:09:02 | |
but the hope is that one day maths will provide the answer. | 0:09:02 | 0:09:05 | |
Our oceans are phenomenal places. | 0:09:09 | 0:09:13 | |
The sheer size and power can be intimidating. | 0:09:13 | 0:09:16 | |
But, that said, | 0:09:16 | 0:09:18 | |
I wouldn't let a rogue wave put you off from taking a dip in the sea. | 0:09:18 | 0:09:22 | |
After all, these are rare events. | 0:09:22 | 0:09:25 | |
The clue is in the name. | 0:09:25 | 0:09:26 | |
From stories of weird and wonderful weather, | 0:09:31 | 0:09:34 | |
we now head off to meet some of nature's ultimate survivors. | 0:09:34 | 0:09:38 | |
These are North America's Great Lakes. | 0:09:43 | 0:09:46 | |
It looks placid here, | 0:09:48 | 0:09:50 | |
but there's something sinister lurking beneath the surface. | 0:09:50 | 0:09:54 | |
The Great Lakes fish are under attack from an animal | 0:09:58 | 0:10:01 | |
that's scraping away their flesh to feed on the blood. | 0:10:01 | 0:10:05 | |
Millions of fish have already died, which in turn, | 0:10:10 | 0:10:15 | |
has caused panic in the fishing community. | 0:10:15 | 0:10:18 | |
You'd see warnings from fishermen, say, | 0:10:18 | 0:10:20 | |
out on Lake Michigan telling the people at Lake Superior, | 0:10:20 | 0:10:23 | |
"Man, look at what happened to us down here." | 0:10:23 | 0:10:25 | |
I hate to say it, but there's nothing that can be done to stop | 0:10:29 | 0:10:32 | |
these and your way of life is in danger as well. | 0:10:32 | 0:10:36 | |
People were determined to find out what was killing the fish. | 0:10:36 | 0:10:40 | |
And what they discovered caused alarm. | 0:10:40 | 0:10:42 | |
They found a bloodsucker | 0:10:45 | 0:10:48 | |
that's been around since the time of the dinosaurs. | 0:10:48 | 0:10:51 | |
A fish, albeit a very weird one, called a sea lamprey. | 0:10:51 | 0:10:55 | |
So, this is a sea lamprey, it looks like an eel. | 0:10:57 | 0:11:00 | |
They're not eels actually, they're their own family. | 0:11:00 | 0:11:04 | |
A lamprey has a mouth that's suited to nothing better than feeding. | 0:11:04 | 0:11:09 | |
It's a suction cup, so it's as strong as a suction cup. | 0:11:09 | 0:11:13 | |
The mouth is ringed with sharp teeth and the middle of the mouth is a | 0:11:13 | 0:11:17 | |
file-like tongue that flicks its way through the scales and skin of | 0:11:17 | 0:11:21 | |
a fish, so that the lamprey is able to | 0:11:21 | 0:11:23 | |
feed on the blood and body fluids of that fish. | 0:11:23 | 0:11:25 | |
It'll go through about 40 pounds of fish during | 0:11:25 | 0:11:29 | |
that parasitic phase, before it moves into a stream | 0:11:29 | 0:11:33 | |
to spawn once and die. | 0:11:33 | 0:11:34 | |
But why was a prehistoric predator suddenly inflicting its death hickey | 0:11:34 | 0:11:38 | |
on the Great Lakes' fish? | 0:11:38 | 0:11:40 | |
Sea lampreys are normally found here, | 0:11:45 | 0:11:48 | |
down the Atlantic coast of North America. | 0:11:48 | 0:11:50 | |
So, how on earth did they end up all the way inland over here? | 0:11:50 | 0:11:55 | |
The Niagara Falls are an impassable natural obstacle. | 0:11:57 | 0:12:02 | |
And they are the only thing stopping lampreys | 0:12:02 | 0:12:05 | |
getting beyond Lake Ontario. | 0:12:05 | 0:12:06 | |
Until we stepped in. | 0:12:08 | 0:12:11 | |
In the 1920s, engineers opened the Welland Canal, | 0:12:12 | 0:12:16 | |
linking Lake Ontario to Lake Erie. | 0:12:16 | 0:12:19 | |
On the one hand, it was a great success - | 0:12:21 | 0:12:23 | |
allowing ships to bypass the Niagara Falls, but on the other, | 0:12:23 | 0:12:28 | |
it was a disaster, which opened the floodgates for lampreys. | 0:12:28 | 0:12:33 | |
Lamprey made it past Niagara Falls in about 1920 | 0:12:36 | 0:12:39 | |
and made it all the way to Lake Superior by about 1939. | 0:12:39 | 0:12:43 | |
Only 20 years after the new canal was opened, | 0:12:45 | 0:12:48 | |
the lamprey had successfully invaded the entire Great Lakes Basin. | 0:12:48 | 0:12:53 | |
It was a perfect storm for invasion. | 0:12:59 | 0:13:01 | |
They had an almost unlimited food supply, because there was abundant, | 0:13:01 | 0:13:04 | |
succulent, tasty fish for the lamprey in the Lakes | 0:13:04 | 0:13:07 | |
and there is nothing preying upon lamprey | 0:13:07 | 0:13:09 | |
or keeping the lamprey in check. | 0:13:09 | 0:13:11 | |
It was a free, open buffet for the sea lamprey. | 0:13:11 | 0:13:13 | |
Plenty of food, perfect spawning grounds, no natural predators. | 0:13:19 | 0:13:23 | |
The lampreys had slithered their way into paradise. | 0:13:23 | 0:13:28 | |
Yes! Or, no. | 0:13:28 | 0:13:30 | |
You see, for the people of the Great Lakes, these things were killers. | 0:13:30 | 0:13:33 | |
A menace that had to be dealt with. | 0:13:33 | 0:13:35 | |
So, whilst the rest of the world were gearing up for the Cold War, | 0:13:35 | 0:13:39 | |
these folks were involved in a fishy fracas. | 0:13:39 | 0:13:42 | |
And to show you how bad it got - prior to the lamprey invasion, | 0:13:45 | 0:13:49 | |
the harvest of fish in Lake Michigan | 0:13:49 | 0:13:52 | |
and Huron was about 20 million pounds annually. | 0:13:52 | 0:13:55 | |
After the lamprey invasion, | 0:13:55 | 0:13:57 | |
that fell to only a few hundred thousand pounds | 0:13:57 | 0:14:00 | |
and that happened over the course of a relatively | 0:14:00 | 0:14:02 | |
short amount of time. | 0:14:02 | 0:14:05 | |
The lampreys were guzzling fish | 0:14:05 | 0:14:07 | |
faster than a sea lion at a sushi bar. | 0:14:07 | 0:14:10 | |
They were that bad. | 0:14:10 | 0:14:12 | |
They were taking five times the amount of fish that humans | 0:14:12 | 0:14:14 | |
were harvesting. | 0:14:14 | 0:14:16 | |
It was make or break time. | 0:14:16 | 0:14:18 | |
They had to find a way to bring this destructive predator under control. | 0:14:18 | 0:14:22 | |
So, they threw everything at it. | 0:14:23 | 0:14:25 | |
Starting with barriers and traps. | 0:14:26 | 0:14:30 | |
They had to prevent the lampreys reaching | 0:14:30 | 0:14:33 | |
or leaving their spawning grounds. | 0:14:33 | 0:14:35 | |
When the traps on their own failed, they tried adding electricity. | 0:14:38 | 0:14:43 | |
Unfortunately, some of those early attempts at lamprey control | 0:14:43 | 0:14:47 | |
were quite... They were abject failures, actually. | 0:14:47 | 0:14:50 | |
And in fact, some of the electrical barriers were very rudimentary, | 0:14:50 | 0:14:54 | |
not much different, some say, than just throwing your toaster | 0:14:54 | 0:14:56 | |
in the river and zapping whatever happens to be in there. | 0:14:56 | 0:15:00 | |
So, the scientists switched to chemical warfare | 0:15:00 | 0:15:03 | |
and developed a weapon that | 0:15:03 | 0:15:05 | |
could kill lamprey without harming any other wildlife. | 0:15:05 | 0:15:09 | |
A chemical called lampricide was the biggest breakthrough in the war | 0:15:13 | 0:15:17 | |
against the lampreys yet. | 0:15:17 | 0:15:19 | |
But the scientists couldn't rest on their laurels. | 0:15:19 | 0:15:21 | |
At any point, the lampreys could develop a resistance to it. | 0:15:21 | 0:15:26 | |
So, they'd won a battle, but to win the war, | 0:15:26 | 0:15:29 | |
they'd have to exploit the lampreys' natural senses. | 0:15:29 | 0:15:33 | |
The sea lamprey has a very refined sense of smell. In fact, | 0:15:33 | 0:15:36 | |
most of their brain is for olfactory purposes. | 0:15:36 | 0:15:40 | |
We call them swimming noses, because they're, basically, | 0:15:40 | 0:15:42 | |
they have a very refined sense of smell. | 0:15:42 | 0:15:45 | |
The scientists found that female lampreys | 0:15:45 | 0:15:48 | |
are attracted to males by smell. | 0:15:48 | 0:15:50 | |
So, they isolated the chemical responsible. | 0:15:52 | 0:15:55 | |
Known as a pheromone, | 0:15:55 | 0:15:57 | |
it was male lamprey cologne and it drove lady lampreys wild. | 0:15:57 | 0:16:02 | |
This pheromone could be used to hoodwink the females | 0:16:06 | 0:16:09 | |
into going into traps on the promise of a bit of hanky-panky. | 0:16:09 | 0:16:13 | |
But there was even better news. | 0:16:13 | 0:16:16 | |
You see, the scientist had managed to isolate the polar opposite | 0:16:16 | 0:16:20 | |
to this attractant. | 0:16:20 | 0:16:22 | |
A naturally occurring chemical called a necromone, | 0:16:22 | 0:16:24 | |
a sort of eau de death, | 0:16:24 | 0:16:27 | |
and the lampreys will do absolutely everything | 0:16:27 | 0:16:30 | |
to avoid this death smell. | 0:16:30 | 0:16:32 | |
Using these natural chemicals, | 0:16:36 | 0:16:38 | |
scientists hope to create a push and pull effect, | 0:16:38 | 0:16:41 | |
using necromones to push lamprey away from places | 0:16:41 | 0:16:44 | |
they don't want them to be, like streams, | 0:16:44 | 0:16:47 | |
with great spawning habitat, and pheromones to pull them into traps. | 0:16:47 | 0:16:53 | |
By turning their own senses against them, | 0:16:53 | 0:16:56 | |
scientists finally had this slippery customer under control. | 0:16:56 | 0:16:59 | |
We've gone from about two million lamprey in the Great Lakes | 0:17:01 | 0:17:05 | |
to only a few hundred thousand, | 0:17:05 | 0:17:07 | |
and that's a significant drop in the lamprey numbers. | 0:17:07 | 0:17:10 | |
It certainly is. | 0:17:10 | 0:17:11 | |
But you have to give respect where it's due. | 0:17:11 | 0:17:14 | |
This brilliant parasite, | 0:17:14 | 0:17:15 | |
with its efficient if disturbing means of survival, | 0:17:15 | 0:17:19 | |
has been giving human beings the run-around | 0:17:19 | 0:17:22 | |
for almost 100 years. | 0:17:22 | 0:17:24 | |
Since 1957, we've probably spent about 800 million or 900 million | 0:17:24 | 0:17:29 | |
to control lamprey. But contrast that to the fact | 0:17:29 | 0:17:31 | |
that the Great Lakes' fishery is worth 7 billion every year to | 0:17:31 | 0:17:35 | |
the people of the US and Canada, and you can see it's a small price | 0:17:35 | 0:17:38 | |
that we pay to have the fishery that we have. | 0:17:38 | 0:17:40 | |
Without the sea lamprey control programme, | 0:17:40 | 0:17:43 | |
we have no fishery to speak of. | 0:17:43 | 0:17:46 | |
Those lampreys almost ruined the Great Lakes fishery. | 0:17:51 | 0:17:56 | |
I've got to say, they got us out of a bit of a jam. | 0:17:56 | 0:17:59 | |
You see, there's a long-held tradition in the UK | 0:17:59 | 0:18:02 | |
that on the occasion of their jubilee, | 0:18:02 | 0:18:04 | |
the reigning monarch is given a lamprey pie, | 0:18:04 | 0:18:07 | |
except that here, lampreys are an endangered animal. | 0:18:07 | 0:18:12 | |
But thankfully, the Canadians sent some over. | 0:18:12 | 0:18:16 | |
And on the 60th anniversary of her reaching the throne, | 0:18:16 | 0:18:19 | |
Queen Elizabeth was thus presented with a lamprey pie. | 0:18:19 | 0:18:23 | |
History does not recount whether she ate it or not. | 0:18:26 | 0:18:29 | |
Our next event takes place in the marshlands of the Negev desert | 0:18:32 | 0:18:37 | |
in Israel, where a battle of a different kind is raging. | 0:18:37 | 0:18:40 | |
Something here has an unhealthy appetite for toads and frogs - | 0:18:43 | 0:18:48 | |
and not just their legs. | 0:18:48 | 0:18:50 | |
Half-eaten amphibians are cropping up all over the place. | 0:18:53 | 0:18:56 | |
But what's causing the slaughter? | 0:18:58 | 0:19:01 | |
Well, a bizarre clue was discovered by a team of entomologists in 2005. | 0:19:01 | 0:19:07 | |
What we found first were several toad specimens | 0:19:09 | 0:19:13 | |
that were carrying larvae on their bodies. | 0:19:13 | 0:19:16 | |
And because no-one had seen this before, | 0:19:16 | 0:19:19 | |
at least in Israel, | 0:19:19 | 0:19:22 | |
we didn't know what they are, so we took them to the lab. | 0:19:22 | 0:19:25 | |
At first, we thought that this was completely incidental, | 0:19:30 | 0:19:34 | |
that they were just larvae accidentally attached to the toads | 0:19:34 | 0:19:41 | |
and we were sure that they would just drop off after a few hours. | 0:19:41 | 0:19:46 | |
Gil and his team decided to keep the amphibians under observation, | 0:19:47 | 0:19:51 | |
and they didn't have to wait long | 0:19:51 | 0:19:53 | |
before they made a macabre discovery. | 0:19:53 | 0:19:55 | |
The researchers couldn't believe their eyes. | 0:20:00 | 0:20:04 | |
The larvae weren't just hitching a ride, | 0:20:04 | 0:20:07 | |
they were attacking their amphibian hosts. | 0:20:07 | 0:20:10 | |
Only after we kept the toads and the larvae in the lab for a while, | 0:20:12 | 0:20:16 | |
we noticed that the larvae kill the frogs. | 0:20:16 | 0:20:18 | |
Frog after frog fell foul to their surprising assassin. | 0:20:19 | 0:20:24 | |
It was clear that this was no accident of fate. | 0:20:24 | 0:20:27 | |
When we thought that they are actually feeding on the toads, | 0:20:28 | 0:20:32 | |
and they just didn't drop off, we said, | 0:20:32 | 0:20:34 | |
"OK, this is something interesting. We should check it out." | 0:20:34 | 0:20:38 | |
Things just didn't add up. | 0:20:40 | 0:20:42 | |
Anything that's small and moving is normally fair game to an amphibian. | 0:20:45 | 0:20:49 | |
The beetle larvae should be an easy meal, | 0:20:55 | 0:20:59 | |
so how has this grisly grub turned the tables? | 0:20:59 | 0:21:02 | |
Gil and his team had to find out. | 0:21:04 | 0:21:07 | |
So, we went back to the field to collect more adults and more frogs | 0:21:09 | 0:21:13 | |
carrying larvae to bring them back into the lab. | 0:21:13 | 0:21:17 | |
Eventually, the larvae will complete their life cycle | 0:21:17 | 0:21:20 | |
or complete the developmental stage. | 0:21:20 | 0:21:23 | |
They will pupate and become beetles, and we wanted to know | 0:21:23 | 0:21:26 | |
what these beetles were. | 0:21:26 | 0:21:28 | |
So, would this bizarre larvae emerge from its pupae | 0:21:29 | 0:21:32 | |
as a grotesque adult beetle? Well, actually, no. | 0:21:32 | 0:21:37 | |
It hatches out as a rather plain ground beetle. | 0:21:37 | 0:21:40 | |
It's always the quiet ones, isn't it? | 0:21:40 | 0:21:42 | |
This unassuming arthropod goes by the name of epomis circumscriptus. | 0:21:44 | 0:21:49 | |
But why had such ordinary-looking beetles | 0:21:52 | 0:21:55 | |
produced such diabolical babies? | 0:21:55 | 0:21:57 | |
Well, Gil has a theory. | 0:21:59 | 0:22:01 | |
We think that it evolved from some sort of counterattack, | 0:22:02 | 0:22:09 | |
as some sort of defence. | 0:22:09 | 0:22:13 | |
And throughout time, | 0:22:13 | 0:22:15 | |
these larvae learned to utilise amphibians as food | 0:22:15 | 0:22:21 | |
and started feeding on them and eventually, | 0:22:21 | 0:22:23 | |
they just stopped feeding on everything else | 0:22:23 | 0:22:27 | |
and fed exclusively on amphibians. | 0:22:27 | 0:22:30 | |
The larvae weren't just fighting back any more, | 0:22:32 | 0:22:36 | |
they were actively inviting the attack, | 0:22:36 | 0:22:39 | |
and in a truly remarkable way. | 0:22:39 | 0:22:42 | |
It uses very minute behaviour, | 0:22:44 | 0:22:48 | |
very minute movements to lure amphibians towards it. | 0:22:48 | 0:22:51 | |
It moves its antennae and mandibles in a repeated cycle | 0:22:51 | 0:22:56 | |
that entices the amphibians to approach and even to attack. | 0:22:56 | 0:23:01 | |
By acting like a tasty snack, | 0:23:01 | 0:23:03 | |
the epomis larvae had managed to turn | 0:23:03 | 0:23:05 | |
the amphibian's own hunting instincts against them. | 0:23:05 | 0:23:09 | |
And then it uses its double-hook mandibles to attach | 0:23:11 | 0:23:15 | |
to the amphibian's body, to lock onto the skin. | 0:23:15 | 0:23:19 | |
Once it is attached, | 0:23:19 | 0:23:20 | |
it starts feeding on the amphibian's body fluids. | 0:23:20 | 0:23:23 | |
And what's absolutely extraordinary is that a single greedy grub | 0:23:23 | 0:23:29 | |
can chomp its way through nine frogs before it is ready to pupate. | 0:23:29 | 0:23:33 | |
A dead frog looks like... | 0:23:36 | 0:23:40 | |
Well, it doesn't look like a frog at all. | 0:23:40 | 0:23:42 | |
It looks like a pile of bones, | 0:23:42 | 0:23:45 | |
like someone just ate all the fleshy parts of the frog, the eyes, | 0:23:45 | 0:23:48 | |
some of the skin, and you get this almost perfect skeleton of bones. | 0:23:48 | 0:23:53 | |
Sometimes it's a complete skeleton, sometimes it's just a pile of bones, | 0:23:53 | 0:23:56 | |
with no shape at all. | 0:23:56 | 0:23:58 | |
It's easy for us to see the frogs and toads as the victims here. | 0:24:04 | 0:24:08 | |
But you've got to remember that | 0:24:08 | 0:24:10 | |
during the course of their lifetimes, they eat thousands | 0:24:10 | 0:24:14 | |
of insects without ever thinking about it. | 0:24:14 | 0:24:17 | |
And the epomis beetle is the only species | 0:24:17 | 0:24:19 | |
we've seen that completely reverses the predator prey role. | 0:24:19 | 0:24:25 | |
So, it's unique and extremely weird. | 0:24:25 | 0:24:29 | |
For our next story, we head north to the Arctic Ocean, | 0:24:33 | 0:24:38 | |
where there's weirdness in abundance. | 0:24:38 | 0:24:41 | |
Living amongst the sea ice are some of our planet's strangest animals. | 0:24:46 | 0:24:51 | |
And perhaps oddest of all is the Greenland shark. | 0:24:54 | 0:24:58 | |
At up to six metres long, | 0:25:01 | 0:25:03 | |
Greenland sharks rival great whites in terms of size. | 0:25:03 | 0:25:07 | |
But in comparison, very little is known about them. | 0:25:07 | 0:25:11 | |
They live at amazing depths, | 0:25:12 | 0:25:15 | |
often below the level that light can penetrate. | 0:25:15 | 0:25:18 | |
So, not only are they hard to find, | 0:25:20 | 0:25:22 | |
it's also a dangerous place to study them. | 0:25:22 | 0:25:25 | |
But sometimes, these sharks are accidentally caught by fishermen. | 0:25:27 | 0:25:31 | |
So, a team of marine biologists | 0:25:33 | 0:25:35 | |
decided to make the most of a bad situation. | 0:25:35 | 0:25:39 | |
In 2010, they set off in Denmark to investigate. | 0:25:42 | 0:25:46 | |
Over the next three years, | 0:25:47 | 0:25:49 | |
they would study every shark that they could get their hands on. | 0:25:49 | 0:25:53 | |
Samples were frozen, so they could be examined later, back in the lab. | 0:26:05 | 0:26:10 | |
The team didn't know it yet, | 0:26:12 | 0:26:14 | |
but one of their discoveries would change the face of biology. | 0:26:14 | 0:26:18 | |
No-one knew how long these remarkable animals live. | 0:26:23 | 0:26:28 | |
Because sharks have a skeleton made of cartilage rather than bone, | 0:26:29 | 0:26:33 | |
the usual method of carbon dating doesn't work. | 0:26:33 | 0:26:36 | |
The biologists had to find another way of ageing them | 0:26:38 | 0:26:41 | |
and they found the answer they were looking for in a remarkable place. | 0:26:41 | 0:26:45 | |
The shark's eye contains proteins formed when it was an embryo. | 0:26:49 | 0:26:55 | |
These can be carbon dated, | 0:26:55 | 0:26:58 | |
so a sample was sent back to the lab and this was the chance to finally | 0:26:58 | 0:27:03 | |
age these mysterious animals. | 0:27:03 | 0:27:05 | |
When the results were analysed, | 0:27:08 | 0:27:10 | |
the oldest shark was shown to be somewhere between 272 | 0:27:10 | 0:27:16 | |
and 512-years-old. | 0:27:16 | 0:27:20 | |
Now, even if we plumped for somewhere | 0:27:20 | 0:27:22 | |
in the middle of that range, | 0:27:22 | 0:27:23 | |
that means there could be a shark living today | 0:27:23 | 0:27:26 | |
that was born on the same day as Isaac Newton, | 0:27:26 | 0:27:29 | |
that lived through the Great Fire of London, | 0:27:29 | 0:27:32 | |
the English Civil War. | 0:27:32 | 0:27:34 | |
There could be a shark out there that remembers | 0:27:34 | 0:27:37 | |
England winning the World Cup! | 0:27:37 | 0:27:41 | |
A shark hundreds of years old is extraordinary in itself. | 0:27:41 | 0:27:45 | |
But this miraculous life-span is even more impressive | 0:27:45 | 0:27:49 | |
when you realise what these deep sea survivors are up against. | 0:27:49 | 0:27:52 | |
I would say they're living on the edge the whole time, | 0:27:56 | 0:28:00 | |
in terms of tolerating the extremes of the cold, | 0:28:00 | 0:28:04 | |
the extremes of pressure that they inhabit, and also, | 0:28:04 | 0:28:08 | |
actually finding the food that they need | 0:28:08 | 0:28:11 | |
just for their general life and routines. | 0:28:11 | 0:28:14 | |
So, it's literally a life of searching for food | 0:28:18 | 0:28:22 | |
in a very hostile environment. | 0:28:22 | 0:28:26 | |
Surviving in the cold and dark is impressive enough, | 0:28:26 | 0:28:29 | |
but there's another bizarre twist to this tale. | 0:28:29 | 0:28:32 | |
If you're searching for food in an environment like this, | 0:28:35 | 0:28:38 | |
it would pay to have pretty good eyesight and I've got to tell you | 0:28:38 | 0:28:41 | |
that when Greenland sharks are born they do have | 0:28:41 | 0:28:44 | |
a perfectly respectable set of peepers. | 0:28:44 | 0:28:47 | |
In fact, they've got larger eyes than most other species of shark, | 0:28:47 | 0:28:51 | |
but as they grow up, something very weird happens. | 0:28:51 | 0:28:56 | |
One of the amazing points of the Greenland shark, | 0:29:00 | 0:29:04 | |
a very unique characteristic that we don't see | 0:29:04 | 0:29:07 | |
in any other shark species, | 0:29:07 | 0:29:08 | |
is a parasitic copepod that is embedded into the eyes | 0:29:08 | 0:29:14 | |
of this particular species, and this is extremely common, | 0:29:14 | 0:29:18 | |
particularly in the mid to high Arctic. | 0:29:18 | 0:29:21 | |
All of the Greenland sharks that you'll encounter | 0:29:21 | 0:29:24 | |
have this particular parasite that's embedded into the eye. | 0:29:24 | 0:29:30 | |
Copepods are tiny crustaceans. | 0:29:30 | 0:29:32 | |
Most are drifters and spend their lives hanging out in the plankton. | 0:29:32 | 0:29:37 | |
But one, called Ommatokoita, has decided to settle down | 0:29:37 | 0:29:42 | |
on the Greenland shark's eyeball. | 0:29:42 | 0:29:45 | |
The parasitic copepod actually anchors right inside | 0:29:46 | 0:29:51 | |
the central part of the eye. | 0:29:51 | 0:29:54 | |
It's got an anchor system, which is called a bulbar, that locks into | 0:29:54 | 0:29:58 | |
the eye, and the thought is that the parasite actually feeds off | 0:29:58 | 0:30:04 | |
the surface of the eye itself. | 0:30:04 | 0:30:06 | |
So, how does a blind shark survive in these Arctic conditions | 0:30:07 | 0:30:12 | |
for hundreds of years? | 0:30:12 | 0:30:15 | |
Well, it appears that it might benefit | 0:30:15 | 0:30:17 | |
from the misfortune of others. | 0:30:17 | 0:30:19 | |
We assume the Greenland shark is a scavenger and it is thought that | 0:30:21 | 0:30:26 | |
it obtains most of the larger prey items from dead animals | 0:30:26 | 0:30:29 | |
that have fallen to the sea floor. | 0:30:29 | 0:30:32 | |
And therefore, if you're going to feed in that particular way, | 0:30:32 | 0:30:36 | |
you obviously need an extraordinarily good | 0:30:36 | 0:30:38 | |
sense of smell to be able to navigate around | 0:30:38 | 0:30:41 | |
and locate those food falls. | 0:30:41 | 0:30:44 | |
Although the Greenland shark has large eyes and they're potentially | 0:30:44 | 0:30:47 | |
adapted in some way for these very low light levels, | 0:30:47 | 0:30:51 | |
I think that the Greenland shark is not majorly dependent | 0:30:51 | 0:30:56 | |
on vision as a cue to locate prey. | 0:30:56 | 0:30:59 | |
Ladies and gentlemen, I give you the Greenland shark. | 0:31:07 | 0:31:11 | |
What an animal. What an animal! | 0:31:11 | 0:31:14 | |
Not only can it lose its vision and live on for hundreds of years, | 0:31:14 | 0:31:18 | |
it's probably the oldest living vertebrate on planet Earth. | 0:31:18 | 0:31:24 | |
It has to be nature's greatest survivor. | 0:31:24 | 0:31:28 | |
We've seen how animals can adapt and survive, | 0:31:32 | 0:31:35 | |
even in the most extreme situations. | 0:31:35 | 0:31:39 | |
But next up, we meet a man who has to cope | 0:31:39 | 0:31:43 | |
with his own rather surreal senses. | 0:31:43 | 0:31:46 | |
Englishman James Wannerton doesn't just see the world differently | 0:31:49 | 0:31:53 | |
to most of us, he tastes it. | 0:31:53 | 0:31:55 | |
What happens is I get one of my senses stimulated, my hearing, | 0:32:00 | 0:32:05 | |
and that immediately gets translated into a taste for me. | 0:32:05 | 0:32:08 | |
It's a real mouth thing as well, it's not, not an association. | 0:32:12 | 0:32:15 | |
It's actually a mouth thing. It's as if I'm actually eating something. | 0:32:15 | 0:32:19 | |
Yes, James can taste words. | 0:32:19 | 0:32:22 | |
And what's more, he's had this peculiar ability since childhood. | 0:32:22 | 0:32:26 | |
I used to go on the tube train with my mum and I used to read off | 0:32:29 | 0:32:34 | |
the names of the stations as we passed through them, | 0:32:34 | 0:32:36 | |
and each of the stations had | 0:32:36 | 0:32:38 | |
a unique and distinct taste and texture. | 0:32:38 | 0:32:41 | |
We used to travel on the Central line, which was my tastiest line, | 0:32:41 | 0:32:46 | |
it was lovely. Not all these tastes are nice, | 0:32:46 | 0:32:48 | |
there were a few stations that were pretty horrible. | 0:32:48 | 0:32:50 | |
Bond Street is one. It's got the taste and texture of | 0:32:50 | 0:32:53 | |
something similar to hair spray. | 0:32:53 | 0:32:55 | |
Tangy. | 0:32:55 | 0:32:57 | |
It's horrible. | 0:32:58 | 0:33:00 | |
Most people's senses work independently, | 0:33:01 | 0:33:04 | |
so why is James' sense of taste triggered by the sound of a word? | 0:33:04 | 0:33:08 | |
Could it be something to do with the one organ that has to interpret | 0:33:10 | 0:33:14 | |
everything that we see, hear, taste, touch and smell? | 0:33:14 | 0:33:18 | |
Imagine that this is my brain. | 0:33:20 | 0:33:23 | |
It allows me to get around and make sense of the world and each part of | 0:33:23 | 0:33:28 | |
that brain is ascribed a specific task | 0:33:28 | 0:33:31 | |
and you need all of those parts for it to function properly. | 0:33:31 | 0:33:34 | |
Let's imagine that the lemon is damaged in an accident, | 0:33:35 | 0:33:39 | |
then I may not be able to recognise myself in a mirror. | 0:33:39 | 0:33:43 | |
And if the apple becomes diseased, | 0:33:43 | 0:33:46 | |
I then think that my left hand belongs to someone else. | 0:33:46 | 0:33:50 | |
Now these are not amusing anecdotes, | 0:33:50 | 0:33:53 | |
these are neurological conditions | 0:33:53 | 0:33:55 | |
that have been recorded by doctors and what they tell us is that when | 0:33:55 | 0:34:00 | |
the brain is damaged, things get taken away. | 0:34:00 | 0:34:04 | |
But in James' case it's not about being taken away, | 0:34:04 | 0:34:08 | |
it's that he's got extra perceptions. | 0:34:08 | 0:34:12 | |
So, is it a case that James' brain, effectively, | 0:34:12 | 0:34:16 | |
has more fruit not less? | 0:34:16 | 0:34:18 | |
To the best of our knowledge, there seemed to be perhaps extra | 0:34:21 | 0:34:25 | |
or strengthened connections between the area of his brain that processes | 0:34:25 | 0:34:29 | |
words and the area that processes tastes. | 0:34:29 | 0:34:32 | |
And there are neurons firing from the word portion of his brain to | 0:34:36 | 0:34:41 | |
the taste portion of his brain | 0:34:41 | 0:34:42 | |
and that causes him to have this extra perception. | 0:34:42 | 0:34:46 | |
So, James' brain doesn't have extra fruit, | 0:34:46 | 0:34:49 | |
just extra connections between the fruit and this allows some of | 0:34:49 | 0:34:54 | |
his senses to talk to each other. | 0:34:54 | 0:34:56 | |
It's like an eye dropper of taste, you know, just drops. | 0:34:56 | 0:34:59 | |
Just drip-drops, one after the other... | 0:34:59 | 0:35:01 | |
-HE IMITATES EYE DROPS FALLING -..for every single sound I hear. | 0:35:01 | 0:35:04 | |
This fantastic neurological phenomenon is called synaesthesia. | 0:35:04 | 0:35:11 | |
The vast majority of the synaesthetic tastes | 0:35:11 | 0:35:14 | |
that I experience are from childhood. A lot of them are sweets, | 0:35:14 | 0:35:19 | |
things like wine gums and sweets you can't buy any more. | 0:35:19 | 0:35:24 | |
So, does James' childhood offer a clue to where | 0:35:24 | 0:35:26 | |
his curious condition came from? | 0:35:26 | 0:35:30 | |
So, the general idea is that perhaps synaesthetes have some | 0:35:32 | 0:35:37 | |
genetic difference that causes either extra connections | 0:35:37 | 0:35:43 | |
or a lack of pruning of connections. | 0:35:43 | 0:35:45 | |
So, when we're born, we have lots of neural connections | 0:35:45 | 0:35:50 | |
and throughout time, those neural connections get pruned down | 0:35:50 | 0:35:54 | |
to the ones that are meaningful for us. | 0:35:54 | 0:35:57 | |
In every newborn baby's brain, | 0:35:58 | 0:36:00 | |
represented by this bunch of bananas, | 0:36:00 | 0:36:03 | |
the senses are better connected. | 0:36:03 | 0:36:06 | |
But we don't need all of these connections to understand the world, | 0:36:06 | 0:36:10 | |
so gradually, one by one, they are severed. | 0:36:10 | 0:36:15 | |
The difference, however, with James' brain is that | 0:36:15 | 0:36:18 | |
one of these connections remains intact, | 0:36:18 | 0:36:20 | |
the one between the piece that processes words | 0:36:20 | 0:36:23 | |
and the piece that processes tastes. | 0:36:23 | 0:36:27 | |
And that is mind-boggling. | 0:36:27 | 0:36:29 | |
So, what if some brilliant brain surgeon discovered a way of snipping | 0:36:31 | 0:36:36 | |
James' extra neural connections now, | 0:36:36 | 0:36:40 | |
freeing him from these strange synaesthetic sensations forever? | 0:36:40 | 0:36:44 | |
Would he do it? | 0:36:44 | 0:36:47 | |
I couldn't imagine life without it. | 0:36:47 | 0:36:48 | |
And I think most synaesthetes would say the same. | 0:36:48 | 0:36:51 | |
Fantastic. And although this might read as faulty wiring, | 0:36:53 | 0:36:57 | |
in my opinion, this is as close as a human can come | 0:36:57 | 0:37:01 | |
to having a proper superpower, | 0:37:01 | 0:37:04 | |
so I couldn't resist asking James what my name tasted like. | 0:37:04 | 0:37:09 | |
Do you know what he said? | 0:37:09 | 0:37:10 | |
Soggy crisps. | 0:37:12 | 0:37:13 | |
Soggy crisps! | 0:37:13 | 0:37:15 | |
So much for the superpower. | 0:37:15 | 0:37:17 | |
For our next sensational story, | 0:37:21 | 0:37:23 | |
we head to the coast of south-west Australia. | 0:37:23 | 0:37:27 | |
This is a favourite spot for shark lovers from all over the world. | 0:37:27 | 0:37:32 | |
And there is no bigger draw than a great white. | 0:37:32 | 0:37:36 | |
But the traditional method of baiting them in with a bag of fish | 0:37:36 | 0:37:40 | |
body parts can put sharks in a bit of a frenzy. | 0:37:40 | 0:37:44 | |
And with water sports enthusiasts all along the coast, | 0:37:45 | 0:37:48 | |
the last thing the authorities want to do here is put sharks | 0:37:48 | 0:37:52 | |
in any kind of frenzy. | 0:37:52 | 0:37:54 | |
So, when they stopped issuing licences to bait sharks, | 0:37:54 | 0:37:58 | |
one tour operator had to get creative. | 0:37:58 | 0:38:02 | |
Necessity is the mother of invention. | 0:38:02 | 0:38:04 | |
When we started shark cage diving, | 0:38:04 | 0:38:06 | |
initially we weren't allowed to use blood and bait, so we looked for | 0:38:06 | 0:38:10 | |
alternatives around other senses that could attract sharks | 0:38:10 | 0:38:15 | |
and music or acoustics was just an obvious thing to try. | 0:38:15 | 0:38:20 | |
We may think it's rather quiet underwater, | 0:38:21 | 0:38:24 | |
but in fact lots of marine animals use sound to communicate. | 0:38:24 | 0:38:28 | |
But using music to attract sharks, | 0:38:29 | 0:38:31 | |
where on earth you begin? | 0:38:31 | 0:38:33 | |
So, when we first trialled this | 0:38:39 | 0:38:43 | |
we just, we grabbed the speaker off one of my mates and we went down, | 0:38:43 | 0:38:47 | |
we put it in the water, connected it to the iPod, | 0:38:47 | 0:38:49 | |
it was my iPod and we just started at A. | 0:38:49 | 0:38:52 | |
Now, I'm a country Aussie kid, | 0:38:52 | 0:38:55 | |
I only have one type of music and it's usually Aussie rock, | 0:38:55 | 0:38:57 | |
so the first album on the list was AC/DC - Back In Black. | 0:38:57 | 0:39:00 | |
When we turned it on, we had sharks within a minute | 0:39:00 | 0:39:03 | |
and they hung around for 20 minutes. | 0:39:03 | 0:39:05 | |
And the sharks were coming up and just rubbing their face on | 0:39:05 | 0:39:08 | |
the speaker and we were just like, "This is the coolest thing ever." | 0:39:08 | 0:39:12 | |
Come on, come on. | 0:39:15 | 0:39:17 | |
Even if we do away with the stereotypes of the long greasy hair, | 0:39:17 | 0:39:21 | |
the patch-covered denim jackets and the head-banging, | 0:39:21 | 0:39:24 | |
I just can't see sharks as heavy metal fans. | 0:39:24 | 0:39:28 | |
So, was Matt's experiment a bit of a freak, a one-off, | 0:39:28 | 0:39:31 | |
or do these animals truly have an appreciation of music? | 0:39:31 | 0:39:36 | |
He was about to find out. | 0:39:36 | 0:39:37 | |
Within days of the story hitting social media, | 0:39:41 | 0:39:44 | |
Matt was inundated with requests to try other music. | 0:39:44 | 0:39:48 | |
We started going through the playlist and what we saw is that it | 0:39:49 | 0:39:52 | |
wasn't just AC/DC that attracts sharks, | 0:39:52 | 0:39:54 | |
there were other songs as well. | 0:39:54 | 0:39:55 | |
We got to one particular shark, Bernadette I think her name was, | 0:39:55 | 0:39:59 | |
that every time we played Talking Heads - Sax And Violins | 0:39:59 | 0:40:03 | |
she would breach out of the water. | 0:40:03 | 0:40:07 | |
The only time we'd see this shark is when that song was playing and we | 0:40:07 | 0:40:10 | |
started to think that maybe sharks had individual preferences. | 0:40:10 | 0:40:14 | |
Matt now had proof that his experiment worked. | 0:40:14 | 0:40:18 | |
The one big question remaining was why? | 0:40:18 | 0:40:21 | |
A lot of species of sharks, like white sharks, | 0:40:22 | 0:40:24 | |
that live in open ocean, or in the pelagic environment, | 0:40:24 | 0:40:28 | |
because of the low rate of encounter of prey, potential prey, | 0:40:28 | 0:40:33 | |
you would expect them to react and to investigate any kind of stimulus. | 0:40:33 | 0:40:37 | |
So, if there is a sound or a smell that they encounter, | 0:40:37 | 0:40:41 | |
because they are curious animals, | 0:40:41 | 0:40:43 | |
they are likely to go and check out what is producing that sound, | 0:40:43 | 0:40:47 | |
as it could potentially be a prey item. | 0:40:47 | 0:40:49 | |
The sharks appeared to enjoy a wide musical repertoire, | 0:40:52 | 0:40:55 | |
but the tracks that worked best had something in common - | 0:40:55 | 0:41:00 | |
a driving bassline. | 0:41:00 | 0:41:03 | |
Low-frequency sounds travel a long way underwater | 0:41:06 | 0:41:09 | |
and it's just possible that sharks can mistake them | 0:41:09 | 0:41:12 | |
for the death throes of an injured fish. | 0:41:12 | 0:41:14 | |
That's because they don't just hear sound, they feel it. | 0:41:16 | 0:41:21 | |
You see, in sharks, | 0:41:23 | 0:41:24 | |
hearing and vibration detection are fundamentally linked. | 0:41:24 | 0:41:28 | |
A fluid-filled tube call the lateral line extends along each flank. | 0:41:28 | 0:41:35 | |
This tube is in direct contact with the water, | 0:41:38 | 0:41:41 | |
via tiny holes in the skin. | 0:41:41 | 0:41:43 | |
When sound causes the water to vibrate, | 0:41:46 | 0:41:49 | |
it moves tiny hairs inside the lateral line | 0:41:49 | 0:41:52 | |
and this tells the shark which direction it came from. | 0:41:52 | 0:41:56 | |
Rock and roll, it does have the largest success probably, | 0:41:59 | 0:42:02 | |
because of the lower down frequency vibrations, the bass beat. | 0:42:02 | 0:42:06 | |
And even the distortion. | 0:42:06 | 0:42:07 | |
It might have something to do with replication of a feeding behaviour, | 0:42:07 | 0:42:11 | |
we don't know, but when a shark comes back to the same song, | 0:42:11 | 0:42:16 | |
time after time, knowing that there's no food available, | 0:42:16 | 0:42:19 | |
what is the attraction? Maybe they just think it's cool. | 0:42:19 | 0:42:24 | |
Sitting underwater, | 0:42:24 | 0:42:26 | |
listening to your favourite song by Metallica and having a shark just | 0:42:26 | 0:42:29 | |
cruise past, looks like he's rocking out to the beat, | 0:42:29 | 0:42:32 | |
letting his hair down and just kicking back with the tunes. | 0:42:32 | 0:42:35 | |
Shark music. | 0:42:42 | 0:42:44 | |
I absolutely love it, because it gives us the opportunity | 0:42:44 | 0:42:47 | |
to redefine the great white as something which isn't a purely | 0:42:47 | 0:42:52 | |
psychopathic fish and it gives people the ability to engage with | 0:42:52 | 0:42:56 | |
this animal in a relatively nonintrusive way. | 0:42:56 | 0:43:00 | |
It's genius. Utter genius. | 0:43:00 | 0:43:02 | |
There's just one thing, I so wish they'd been into The Ramones. | 0:43:02 | 0:43:06 | |
From a man with a finger-licking lexicon... | 0:43:10 | 0:43:13 | |
Tastes horrible. | 0:43:13 | 0:43:15 | |
..to a shark with an appetite for music, | 0:43:15 | 0:43:19 | |
we've seen how the senses can perplex | 0:43:19 | 0:43:21 | |
and please us in equal measure. | 0:43:21 | 0:43:23 | |
From frogs to fish to beetles to humans, weirdness has no boundaries. | 0:43:26 | 0:43:33 | |
It comes in all shapes and sizes. | 0:43:33 | 0:43:36 |