We live in a very weird world.
And at winter time, it just gets weirder.
This is a perfect circle in the ice.
It's pretty wild.
We've scoured the globe to bring you the most curious creatures...
I would pay serious money to see this.
..the most extraordinary people...
It's all about having fun during winter.
..and the most bizarre behaviour.
We examine the evidence,
test the theories...
..to work out what on earth is going on.
Our first weird and wonderful story is all about snow.
Now, we love to play around in the stuff and animals, well,
they're no exception.
DOG BARKS
MUSIC: Merry Christmas Everybody by Shakin' Stevens
# Snow is fallin'
# All around me
# Children playin'
# Having fun
# It's the season
# Love and understanding
# Merry Christmas everyone. #
Undeniably wonderful.
But I have to tell you the star of this story is nowhere near as cute
as that lot, but it does take playing in the snow
to a whole new level.
Time to head to Russia.
It's 2012, in the city of Yekaterinburg, in the Urals.
And a local family have caught a crow on camera.
Doing something very strange.
The crow has found a lid from a jar of mayonnaise
and in front of the astounded family's eyes,
it uses it to snowboard.
So what on earth is this crazy crow up to?
It looks like it's having great fun.
Nicky Clayton from Cambridge University is one of the world's
leading experts on corvids - that's the crow family.
SQUAWK!
Wheeee!
All the way down, back up to the top.
It's just doing it time and time again. It's so cool.
This doesn't surprise me at all.
You see corvids doing so many weird and wonderful things.
It's interesting watching animals play, isn't it?
Are they just having fun?
Are they just messing about?
Or is there something more involved?
One idea is that you learn
quite a lot in a safe environment from playing.
It gives you the opportunity to try things out.
And this bird really is trying things out.
Just watch what it does next.
One interesting observation is that it tries it on the bit of the
rooftop without snow. Sees it doesn't work...
..and instead focuses on the bit with snow, where it will slide down.
So, by trial and error, the crow's figured it out.
Clear evidence of learning through play.
But that's nothing new.
There are countless examples of this right across the animal kingdom.
Cats chase string to practise
catching mice and pouncing on stuff hones their killer skills even more.
But crows, now, they are really special.
Corvids, in general, are extremely intelligent animals.
In fact, my husband and I refer to them as the feathered apes,
because, when it comes to cognitive abilities,
crows are as intelligent as chimpanzees.
You see, I told you, crows are special and
there is one particular area where these feathered ape brains really
come into their own and that's tool use.
New Caledonian crows, in captivity,
have been observed bending a piece of wire into a hook to retrieve a
bucket of food.
And jays will drop stones into a tube containing water
to raise the level and get the prize.
And it's not just crows in captivity.
In the wild, the New Caledonian crow uses sticks to catch grubs.
And the Japanese carrion crow has taken tool use even further.
It purposefully drops nuts on to busy pedestrian crossings.
Cars then break the outer casings
and once the traffic stops,
the crows safely retrieve their rewards.
Simply incredible.
But in all of these examples,
these cunning corvids have one thing in common,
for their complex endeavours they get a reward - food.
But the bizarre thing in our video is that this crow doesn't get any
food at the end. So why bother?
The fact they seem to be doing this just for fun, without any reward,
suggests that it's much more than just learning.
A number of studies have found that when animals engage in play,
their brains grow.
So, actually, the crow in our video
is doing so much more than just messing around in the snow.
I mean, yes, it's learning.
Yes, it's stimulating itself.
But what sets it apart from other animals
is that it's growing its brain.
Amazing!
Big brained, highly-intelligent animals,
like us and like crows, love to play.
Because play is good for the brain.
So, there you go, snowboarding actually makes your brain bigger.
Now, winter really is full of the tales of the unexpected,
from the surprising...
Whoa!
..to the scary...
Heads up, heads up. Right at us.
Ohhh!
..to the downright strange.
And our next story is strange with a capital S.
The state of Michigan, USA.
The small town of Vestaburg is home to Jason Robinson.
It's something that I've never seen around here and I know a lot of
people that have been here their whole lives
have never seen anything like that.
It's unusual.
I spend a lot of time outside.
I've seen lots of beautiful stuff, in the woods, in the water.
For the last ten years, Jason's been taking the same route to work.
My commute is very short and peaceful.
There is no traffic to be concerned about.
I notice things.
I take in what's out there when I drive to work.
But, one day last winter, his daily commute took a surprising turn.
I thought that it was such a strange occurrence
that I wanted to share it with people.
This is Schmeid Road, where it crosses the Pine River.
And this is a perfect circle in the ice and it's pretty wild.
I've never seen anything like that in nature first-hand.
I didn't have any idea how it happened.
It looked almost supernatural.
A perfect disk of ice, almost three metres across,
gently rotating on the surface of the water.
And what's even more bizarre is that Jason is not the only person to have
witnessed this spectacular scene.
These spinning circles of ice have been spotted all over the world.
So, what exactly is behind this mesmerising phenomenon?
I didn't know what to think. I initially thought it was man-made.
I thought that some crazy hillbilly with a chainsaw cut it.
Honestly.
Well, hold on a minute, Jason,
that's not such a crazy theory, is it?
Remember crop circles?
These mysterious shapes
began appearing in the British countryside in the 1970s.
Everyone thought they were created by aliens,
but it turns out they were just an elaborate hoax, made by humans.
Could these ice circles also be a hoax?
I had a lot of people contact me and think that I did it.
People I know, friends said,
"How did you cut that circle in that ice? How did you get out there?"
But the ice was so thin I couldn't imagine anybody was brave enough to
venture out there and make a circle on the ice, on the thin, thin ice.
Jason's right.
In all of these cases,
the ice simply isn't thick enough to carry the weight of a human.
As weird as it seems,
these incredible circles must have been created naturally.
But how?
Well, last year,
scientists at the University of Liege in Belgium
made a fascinating discovery.
Now, here's a block of ice that we've infused with blue dye and
here's some water.
So, let's see what happens when I put the ice into the water.
If I just centre it here.
There we are.
And look at that.
It's started to spin.
But the question is, why?
Well, as the ice melts in the water,
it chills the water beneath it and when that water reaches
4 degrees Centigrade, it becomes denser than the water around it.
Denser and therefore heavier, and it starts to sink.
And as it sinks, it spirals,
causing a vortex
and it's this spinning which turns the disk of ice above it.
Look at that! It's doing it absolutely perfectly.
And in nature, in the river, as it spins round and round,
the edges are ground down
and gradually it becomes a perfect circle.
And these natural shapes have
actually inspired some very unnatural behaviour.
The natural ice disk was an inspiration for this project.
Meet Janne Kapylehto. Inventor of the ice carousel.
Ice carousel is all about having fun during winter.
Janne uses chainsaws and ropes to create enormous disks on frozen
lakes in his native Finland.
It seems that everyone's invited.
Although inspired by nature,
Janne doesn't exactly rely on vortices to get his disks turning.
There's many ways to make the ice carousels spin.
I usually use outboard motors.
Janne's creations have become an obsession and now he's got the whole
of Finland in a spin.
MUSIC: You Spin Me Right Round by Dead Or Alive
The more popular they've become, the bigger they've got.
Janne's latest creation is 100 metres in diameter,
which apparently is a world record.
You could say he's revolutionary.
Now, ice can be a lot of fun for humans and animals,
but for some species it's a matter of life and death.
September 2017,
Julie Stevenson and her husband were on a trip around the Arctic when
they experienced something truly spectacular.
We were like, gobsmacked.
It was like...
Did we actually experience that?
On the last day of their month-long expedition,
they were anchored off the coast of Wrangel Island,
when Julie spotted something strange.
What we saw from the ship was a whole lot of like, fluffy dots.
They looked like sheep.
They looked like hundreds of sheep.
Now, hold on. Sheep, in the Arctic?
Surely that's a bit unlikely.
My husband was in the bridge,
he took his binoculars and looked through,
and he said, "They're polar bears!"
The director of Wrangel Island reserve said,
"No, they can't be polar bears, there's too many."
So we were excited and keen to go and have a look.
And as they got closer, the white dots began to take shape.
It was like, "Oh, my gosh, there's so many bears!"
There's like hundreds of bears here.
I did get emotional.
I was crying, people were hugging me because I found it so moving.
So profound. To see so many bears in one place.
Over 200 polar bears,
that's more than 1% of all the polar bears on the planet, in one place.
Now, these are solitary animals,
it's rare to see any together.
So seeing this many was simply extraordinary.
Indeed, so surprising it even baffled polar bear experts.
Absolutely amazing. I would pay serious money to see this.
I've been working with polar bears for 42 years,
and to see that many in one location was incredibly unusual.
Now, polar bears spend the majority of their lives alone.
So what had brought them together in this one place?
And in such large numbers.
Well, the bears aren't the only animal on the beach.
Yes, that is a whale carcass.
Whale blubber is absolutely packed full of calories,
it's the perfect meal for a hungry bear.
But the question is, on this remote island,
how did so many bears find the feast at the same time?
Well, many animals have a keen sense of smell.
But the polar bear's is in a class of its own.
Polar bears have an amazingly well-developed sense of smell,
that part of their brain that deals with scent is probably
more developed than in most other mammals.
A polar bear's sense of smell is
actually 150 times better than a human's.
They can smell a seal from 20 miles away.
And from three feet below solid ice.
OK, so any polar bear within 20 miles could pick up the scent of
that carcass, but here's the problem.
You see, polar bears are essentially solitary animals,
in fact they are pretty anti-social.
It's one of the reasons why they have such huge home ranges, so they
can simply avoid one another.
So what could have brought 200 of these animals together within
a 20-mile radius in the first place?
Well, in winter, polar bears
spread out across thousands of miles of ice.
But in summer, when the ice has melted,
the polar bears are limited to patches of land.
Forcing them close together.
Normally in the summer, polar bears are waiting.
They are waiting for the ice to form
so they can go back out onto the pack ice and hunt seals.
And this corner of Wrangel Island is a special spot.
Now, we've got a theory as to why
all of these polar bears
came together for this extraordinary event.
You've got to imagine that this ball is Wrangel Island.
At this time of year,
the bears are essentially trapped on it because they are waiting for the
sea around it to freeze so that they can go out and hunt.
But, historically,
it's this corner of the island where the seas freeze first.
And clearly, the bears remember this, too,
as they've all gravitated in that direction.
It's a bit like they're waiting for a bus, except the bus is very,
very late and therefore you've got a big queue of bears.
And then they get a bonus, because a very stinky whale carcass turns up,
and they are all hungry so they simply can't resist it.
And what you've got is the perfect recipe for a polar bear party.
Except, haven't we forgotten something?
Like I've said, polar bears simply don't like other polar bears.
I thought that there would be a lot more argy-bargy,
a lot more fierceness between them.
And that's an understatement.
200 unsociable, hungry bears?
It should have been a bloodbath.
The bears were so relaxed,
there was no overt growling or lip curling to chase another bear away.
OK, so why the truce?
The reason the bears weren't fighting is because you had this
enormous food resource. Everybody was going to get a full stomach.
If there was a limited food supply, so say, rather than a big whale,
there was a small seal carcass, there would probably be an argument.
So they are focused on feeding rather than fighting.
And this makes for a once-in-a-lifetime experience.
I've got to admit to being very, very jealous.
I didn't really have a thing for polar bears
until I saw so many of them.
Then I got how important it was.
And it was such a privilege.
I was sort of shell-shocked.
Even now, thinking about how amazing it was.
All right, don't rub it in!
So, while crows are snowboarding in the Urals...
..and a Finn has us all in a spin...
This carousel makes people happy.
..some polar bears are having a party in the Arctic.
What a weird wintry world we live in.
For our next curious case, we travel from the top of the world...
..right down to the bottom.
Antarctica.
Home to millions of Adelie penguins.
Ice and sea.
And sea and ice.
Life is pretty good by penguin standards.
But inland, 70 miles away from the colony at Cape Royds,
lies one of the most inhospitable places on Earth.
The dry valleys.
So barren, it's like the surface of Mars.
And apart from a few bacteria, there's no life here.
But there is evidence of death.
When you're hiking along for hours on end, and you come across nothing,
and suddenly you see something that doesn't look like every other rock,
it catches your attention.
I was working in the Dry Valleys,
I hadn't seen any animal life in months.
I was on an eight-hour hike
and suddenly I almost tripped over a dead body.
Stopped to have a look, and it was a dead penguin.
When I realised it was an Adelie penguin and not a Rock,
it was really quite staggering.
How the hell did this penguin get so
far inland away from where it's supposed to be?
And this sad discovery wasn't a one-off.
I was usually hiking about eight to 12 hours a day,
and I'd stumble across at least one carcass a day.
It is fairly bizarre,
it's clearly not the environment they're meant to be in.
Why these marine animals have died so far from the sea was baffling.
But then, in 2006, a documentary film crew
stumbled across some evidence.
They filmed a penguin behaving very strangely.
The group of penguins on the right are heading out towards the sea.
The penguin on the left is on its way back to the colony.
But this penguin, the one in the middle,
doesn't seem to know which way to go.
Then it heads off in an entirely different direction.
Heading inland, straight towards the Dry Valleys.
So what's going on?
OK. Let's have a little recap on the day-to-day activities of
the breeding Adelie penguin.
The eggs and the young are here, at its home in the colony.
And if it's got young, they'll need feeding,
so they will travel across the ice to the sea,
to hunt for fish, and then they will return across the ice to the colony,
where they will regurgitate them.
And that's about it, really.
It's colony to sea, sea to colony,
colony to sea, and back again.
But what about that single penguin,
travelling off in the wrong direction,
all alone?
What was it doing?
In the world of penguins, group behaviour is hugely important.
They go everywhere in flocks.
For a single penguin to leave a flock means that there is some major
factor that is involved.
So what could possess a penguin
to set off on this solo suicide mission?
One of the theories about why penguins end up in the Valleys is
that they are using light reflected off water and the clouds
as navigation aids,
and so the lakes inside the Valleys reflect some of this light on the
clouds and the penguins,
thinking it's the ocean, start heading inland.
It's an interesting idea, but does it stand up?
Is this how penguins navigate, using visual landmarks?
Well, animals use all kinds of ways to orient themselves.
We know bears use their amazing sense of smell.
Turtles use invisible magnetic fields to find their way.
Some birds even navigate using the stars.
But scientists have discovered that
penguins have another way of getting around.
Some researchers are interested in how penguins oriented,
and so they travelled to Antarctica and they captured about a dozen
penguins and they flew them to the South Pole,
which is a featureless plain.
And so they released these penguins and they found that as long as the
sun was shining, they all went north-east.
When the sun became obscured, they wander every which way.
So they concluded that these penguins were using the sun
to orient themselves to the point of the compass.
Penguins have an in-built compass set by the sun.
They don't find the ocean by looking for it,
their compass guides them toward it.
A visual clue, like a shimmering mirage,
could not have confused our penguin.
So what was pulling it towards the Dry Valleys?
Well, David has an extraordinary explanation for
this very strange behaviour.
It's a pretty widespread phenomenon amongst animals,
including humans, where a very, very small proportion of individuals
have some malfunction in their brains
where they confuse left with right.
They think they are going the right direction,
but they are going the opposite direction.
This penguin was completely convinced that the direction it was
going would get it to the ocean.
The best explanation for what this penguin is doing in the clip was it
was expressing some form of dyslexia.
Our little penguin had it all topsy-turvy.
You see, in his head he thought
that he was moving in the right direction,
and all of the other penguins had it wrong.
It was a classic case of mirror image malfunction.
Yes, his internal compass was completely askew.
North became south, south became north.
So while he thought he was heading to the sea, in fact he wasn't.
He was heading off on a long walk to the Dry Valleys.
And certain death.
Poor little penguin.