STEPHEN FRY: 'It's hard to describe how still it is
'on a glacier surrounded by a fresh blanket of snow.'
Which makes the fact that I'm moving
at 490,000mph
all the more extraordinary.
But I, like everyone, like you,
am hurtling through space on our annual journey around the sun.
'For the first time,
'this series explores how all life on our planet...
'..is shaped by this orbit.
'How where you are on Earth...
THUNDER CRACKS
'..makes a world of difference.
'And no matter how far apart...
'..how everything is connected.
'Epic weather systems...
'..trigger seasonal spectacles...
'..driving animals to move...
'..to fight...
'..and even to love.
'Filmed across more than 60 locations...
'..we'll see this unique annual journey
'through the eyes of incredible animal families...
'..as they take on everything the seasons can throw at them.
'It's high in the Northern Hemisphere
'where winter hits earliest.
'By late-October,
'most animals have already fled south
'to escape the brutal cold.
'Only the toughest remain.
'For now, this mother and her two-year-old cub
'still have time to play.
'It will be the last winter they spend together.
'Polar bears are solitary animals...
'..and she only has until spring to prepare her cub...
'..for a life alone.
'Since birth, he's followed in her footsteps...
'..and she's had to hunt for both of them.
'The ice in Svalbard's fjords acts as their main hunting platform.
'But right now, it's only just forming...
'..and opportunities are thin on the ground.
'A ringed seal.
'A lifeline.
'The cub knows to stay back.
'Every week without food...
'mother and cub lose a tenth of their weight.
'Tough times lie ahead.
'The seasonal challenges animals face
'are all created by a quirk unique to our planet.'
Our journey around that nuclear reactor
affects almost all life on Earth.
And as we circle it,
we do so on a titled axis.
'It's this that creates the seasons.
'During summer, the Northern Hemisphere
'leans towards the sun.
'But six months later, the north tilts away from the sun...
'..and days become shorter and darker.'
Despite being clad head to foot in specialist winter gear,
I wouldn't survive a night on this hillside.
'Thankfully, I won't have to.
'But this mother and cub must be prepared to face
'some of the toughest conditions on the planet.
'It's the last time they'll see the sun this year.
'Polar winter is here.
'This one night will last for more than a 100 days.
'Somehow, this mother will have to find enough food
'to see them through the dark times ahead.
'When it's winter in the Northern Hemisphere,
'at the other end of the Earth, it's summer.
'The Southern Hemisphere is tilted towards the sun...
'..bathed in its warmth and light, and teeming with life.
'After a two-week fishing trip,
'these king penguins are heading home
'to a tiny speck of land,
'1,000 miles south of the African continent.
'Some have swum up to 4,000 miles
'in search of food.
'They're home.
'But the moment they set foot on land,
'all that grace disappears.
'Still, he needs to keep moving.
'After so long at sea,
'he's desperate to reunite with his mate.
'But a million other penguins have had the same idea.
'Oh, my!
'This might take some time.
'It's December,
'and in the Southern Hemisphere, that means summer.
'A tenth of all the king penguins on Earth
'have come to Marion Island to breed.
'And this male needs to find his mate in the crowd.
It may seem an impossible task,
'but king penguins have an extraordinary ability
'to locate one another.
'He can filter the cacophony of half a million birds
'to isolate her call.
It's known as the cocktail party effect.
'Rather apt for a bird in a dinner suit.
'Hearing her is one thing.
'Getting to her another.
'Every corner of the colony is contested.
'And penguins were enforcing social distancing
'long before we'd heard of it.
'Finally, reunited.
HOOTING
'She's waited more than two weeks,
'going without food or water, to guard their newly-laid egg.
'Now it's his turn to care for it.
'This egg is the pair's only chance to raise a chick this year.
'Just getting it to hatch will take incredible devotion.
'Taking turns to sit on the egg
'while the other feeds in the summer seas.
'This far south,
'the sun's rays hit Marion Island at an angle.
'But further north,
'the Earth's tilt means that in Southern Africa,
'along the Tropic of Capricorn, the sun is directly overhead.
'Here, its energy is at its most concentrated,
'super-heating the land,
'driving cloud formation
'and bringing the rains to Botswana.'
THUNDER RUMBLES
'There couldn't be a more perfect time to be born.
'Much of an elephant's existence
'revolves around the search for water.
'During the rainy season in the Southern Hemisphere,
'there's so much of it that life is about as easy as it gets.
'But it doesn't stay like this for long.
This one-month-old baby elephant's first year
'will be the most challenging of his whole life.
'The savannahs are at their lushest,
'the rivers at their fullest,
'and there's a baby boom in Botswana.
'There's a world of new life to discover.
'With refreshment at every turn.
'Just as well.
'An adult elephant needs over 200 litres a day.
'But the baby gets all he needs from milk.
'So a trip to the river means it's time to play.
'Life may seem idyllic now,
'but danger is never far away.
'There are lion prides
'that specialise in taking down elephants.
'And it's the smallest that are the most vulnerable.
'But during the wet season,
'there's plenty of easier prey for the lions to chase.
'Botswana has distinct periods of summer rain and winter sun.
'But along the equator,
'the seasons, as we know them, all but disappear.
'Consistent sunlight all year round
'creates the ideal conditions
'for tropical rainforests to thrive.
'Animals living here don't waste precious energy
'surviving seasonal extremes, or migrating to escape them.
'Instead, they can put it into something
'a little bit more... fabulous.
'From the weird... to the wonderfully colourful.
'In the jungles of Papua New Guinea and Northern Australia,
'there are a few who focus on more artistic pursuits.
'He may seem a little drab
'compared to other birds of paradise...
'..but he's called a magnificent riflebird
'for a reason.
'He's dedicated his entire life to the art of seduction.
'But to really shine, he needs a partner.'
HE WHISTLES
'Ah! The first audience of the day.
'And this branch, his personal stage
'for a routine he's been perfecting for years.
'It's rarely been seen, let alone filmed.
'With special wing feathers,
'he puts on a shape-shifting display.
'But not every riflebird is what they seem.
'And that's no she.
'Juvenile males look and act like females
'to cheat a front-row seat
'and learn from the best.
'It can take five years of study to master this dance.
'But once he sees through the charade...
'..he has no moves left to teach
'but the cold shoulder.
'No matter how much his fan looks up to him.
'Here, the tropical sun shines more or less 12 hours a day...
'..all year round.
'But far to the north, in the Arctic...
'..there is nothing but darkness.
'It's the winter solstice.
'The shortest day of the year.
'When the Northern Hemisphere
'is tilted as far away from the sun as it can be.
'From this point onwards...
'..days begin to get longer.
'But this polar bear won't see the sun rise
'for another 56 days.
'If it even survives that long.
'The relentless search for food continues
'for the polar bear mother and cub.
'A reindeer fallen victim to the winter storms
'offers some relief.
'But together, they need more than 170,000 calories a week.
'An adult reindeer provides less than half that.
'If they're ever going to see the sun again,
'she'll need to enforce some portion control.
'While the sun may be long gone from the Arctic,
'its presence isn't forgotten.
'Solar winds engulf our planet.
'And these latitudes bear witness to a display on a planetary scale.
'The northern lights.
'When charged particles collide with Earth's magnetic field
'at millions of miles an hour,
'they release enormous amounts of energy.
'These lights are the only way we ever see
'this invisible magnetic force.
'Yet we are still discovering
'how fundamental it is to life on Earth.
'Recent studies suggest it may even help one animal
'catch its next meal.
'Winter storms have covered this red fox's home
'in a blanket of snow three feet deep...
'..and hidden the rodents it usually hunts.
'For some animals,
'this might be a barrier too great to overcome.
'But a fox is cunning and has excellent hearing.
'It's trial... and error.
'But there is one thing he can do to improve his chances.
'Scientists believe red foxes have a sixth sense
'for the same magnetic force that causes the northern lights.
'And they can use it to triangulate their prey's position.
'Pointing to the north-east, he waits for the sound of his prey
'to cross the angle of the magnetic field.
'The sweet spot.
'Using this technique, his hit rate increases fourfold.
'In January's bitter cold,
'it can make the difference between life and death.
'After weeks with little energy from the sun
'the Northern Hemisphere continues to cool.
'Many animals that migrated south to avoid the cold
'are just arriving at their destinations.
'Where better for a spot of winter sun than the coast of Florida?
'Home to luxury apartments,
'golden sands...
'..and warm tropical waters.
'A favourite not just for America's holiday-makers,
'but blacktip sharks, too.
'12,000 of them.
'Just like everyone else,
'they're making the most of the warm water.
'But there's trouble in paradise.
'Great hammerhead sharks,
'up to six metres long,
'have been waiting all year for this seasonal feast.
'For the blacktips,
'travelling in numbers is far safer
'than being caught out alone.
'Together, they have more chance of spotting danger.
'But with eyes on the sides of its head,
'a hammerhead sees in almost every direction.
'They scan for weakness...
'..constantly testing the school.
'One wrong move...
'..is all it takes.
'Despite the risks,
'the promise of food and warmth
'makes the journey south worthwhile.
'Constant sunlight provides a refuge for animals throughout the tropics.
'But for those that live here year-round,
'there are more pressing matters at hand.
'The magnificent riflebird
'is still looking for love.'
HE WHISTLES
'A female... surely.
'He needs to entice her onto the stage.
'A good start.
'But she holds all the cards.
'She'll only mate with the most impressive male.
'Beauty is in the eye of the beholder.
'Well, behold this!'
FLAMENCO MUSIC PLAYS
'A flutter of the wings
'shows she approves.
'It's time for his signature move.'
FLAMENCO GUITAR MUSIC
'It seems to do the trick.
'And after all that,
'he may never dance for her again.
'Her loss!'
HE WHISTLES
'There are plenty more birds in paradise.
'As our planet continues its journey around the sun,
'the seasons start to turn.
'Over 1,000 miles south of the equator,
'the rainy season will soon end.
'Fewer clouds in the sky
'means less protection from the searing sun.
'So the herd seeks shade in the bush.
'The baby elephant's grown more confident and curious.
'He's still not got the hang of that trunk, though.
'It's one of the most complex organs on Earth.
'Delicate enough to pluck a blade of grass,
'strong enough to lift 250 kilos.
'No wonder it'll take the rest of the year to master.
'At least he has plenty of family to practise with.
'Though his older cousin
'can get a little rough.
'It's good preparation for the future.
'So far, all he's known is an easy life.
'But from this point on,
'his home becomes drier.
'The herd will weaken,
'and the lions are waiting.
'For the rest of the year,
'the matriarch must keep the herd from danger
'and guide them on a relentless search for water,
'as rain becomes a distant memory.
'Summer across the Southern Hemisphere
'is coming to an end.
'After cradling their egg for 55 days...
'..the moment the devoted king penguin parents
'have waited for
'has finally arrived.
'It's time to welcome their chick into the world.
'The egg our king penguin parents have been protecting since December
'has finally hatched.
'It will take the rest of the year to raise her.
'The longest parenthood of any bird.
'Exhausted and unsteady...
'..she's ready for her first meal.
'She needs to build her strength as quickly as she can...
'..if she's to survive the voracious predators...
'..and worsening weather.
'As the Southern Hemisphere tilts away from the sun,
'days will get shorter and tougher.
'But in the north,
'the first signs of spring are fast approaching.
'Warmth floods back into Scandinavia's forests.
'A very welcome change for the resident red squirrels.
'They don't hibernate through winter.
'But on a cold morning,
'he's certainly not opposed to a lie-in...'
KNOCKING
KNOCKING CONTINUES
'..when he can get it.'
KNOCKING CONTINUES
'They just won't shut up.'
KNOCKING
'Fine!
'Might as well make the most of the longer days, now they're here.
'If he's not sleeping,
'he's thinking about his next meal.
'This early in the year,
'there's not much but lichen and bark.
'And too many fellow foragers
'to contend with.
'Including other reds.
'Thankfully, he's, well, squirreled away
'his own secret stash.
'In autumn, when the trees were bursting with nuts,
'he hid almost 3,000 across the forest.
'He thought about his nuts so much,
'his brain had to grow to cope.
'A squirrel's hippocampus expands by 15%
'just to remember where it cached them.
'Yes!
'Many of the other squirrels' stockpiles
'are empty this late in winter,
'so they're on the lookout for an easy meal.
'Packed with protein and rich in fats...
'..these cheats will do whatever they can
'to get their hands
'on his nuts.
'He'll have to keep defending
'his hard-earned stash a little longer.
'As winter comes to an end...
'..more light falls across the Northern Hemisphere.
'Each day, like a tide,
'the sun's life-giving rays
'creep further and further into the Arctic.
'Until, finally...
'..after a 112 days...
'..the sun rises in Svalbard once more.
'The polar bear mother has made it through the long winter.
'And despite all its challenges...
'..so has her cub.
'They say raising a child
'is one of the hardest things you can do in life.
'Letting them go...
'..is even harder.
'She must push him away
'for his own good.
'She's done all she can.
'In his whole life,
'he's never spent a day on his own.
'Now, like all male polar bears,
'apart from the briefest of moments,
'he could roam this frozen wilderness alone
'for another 20 years.
'If he remembers what his mother taught him,
'he might just survive.
'Soon, the sun will hang in the sky 24 hours a day,
'slowly melting away this frozen world
'with its unfathomable power.
'In just one second,
'our sun releases more energy than all mankind has used
'since the beginning of time.'
Just let that sink in.
From now on, it's going to beat down on our northern pole
for just a few extra minutes each day.
Unsurprisingly, the effects are immense.
Even now, its warming touch is changing these icy valleys.
And as the Northern Hemisphere leans once more towards the sun,
great change will sweep the globe.
Spring is on the way,
bringing with it new beginnings
and great hardship
for those who call this planet home.
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