Autumn The Great British Year

We are an island nation,

surrounded by seas and buffeted by winds...

..with weather and seasons like nowhere else on Earth.

Unpredictable, always changing,

defining the nature of our extraordinary land...

..and giving us the great British year.

CRASHING OF WAVES

A tempest is coming.

One that will turn all life in Britain on its head.

SEAGULL SQUAWKS

All that is old will be swept away,

clearing the way for something new.

Over the next three months, the sun's power will fade.

Wild weather will batter our shores, transforming the landscape.

It's the time of last chances.

Autumn is coming.

BIRDSONG

For most of us, the autumn equinox slips by unnoticed,

but nature has already sensed this season's approach.

ROBIN SINGS

Trees are the first to feel the fading of the sun's energy...

..and react in spectacular fashion.

As October unfolds, acers and ashes,

beeches and oaks, transform into a riot of colour.

We British adore this time of year.

On a single Saturday, 4,000 people enjoy the garden

here at Stourhead in Wiltshire.

A garden designed 300 years ago to showcase this magical autumn event.

But there's a bittersweet sadness in this spectacle.

It's a flamboyant display of death.

The leaves are dying so that the tree itself might live.

The leaves are the trees' solar panels,

turning sunlight into energy.

Soon there won't be enough sunlight to power them.

In fact, they don't actually turn brown, they just become less green.

They stop producing chlorophyll, revealing red and gold pigments

that were always there, just hidden.

The tree has already stored what it needs

to get through the coming months.

It doesn't need its leaves any more.

Rather cleverly, it kills them off.

For trees, survival is spectacular.

There is no single moment that marks the start of autumn.

Here in the Wye Valley, running between England and Wales,

it usually stays green for a week longer than up in Scotland.

Overall, the sweep of autumn moves from north to south

until Britain is transformed.

The days are getting shorter and there's a chill in the air.

You might think the animals would be hunkering down.

In fact, the shortening days stir them into action.

But they must pick their perfect moment.

In this web-strewn Dorset forest, battle-cries carry on the wind.

DEER SQUEALS

A male sika deer.

He's spent all summer preparing for autumn

and is in peak condition.

He's gathered a harem of females.

Over the next few weeks, they will each come into season.

If his timing's right, he will father the next generation.

But if he's made his play too early, the consequences could be fatal.

There's a challenger in the forest,

waiting for his chance to steal the harem.

Any day now, the two males will meet in combat.

While his rival puts on the pounds,

the defending male puts all his energy into guarding his females,

and the effort is taking its toll.

As the days pass, the defender finds he's too busy to feed.

Meanwhile, his challenger bides his time

until he thinks the moment is right.

He has chosen today.

The challenger enters the ring.

The pale challenger may be bigger,

but the smaller, defending male is light on his feet.

Both risk breaking their necks or being gored.

The defender is getting a beating.

He's fighting not just for his females,

but now for his life.

He's held on...

just.

And that's good enough. He's still king of the herd.

But the price of victory may still be the death of him.

In trying to father all the harem's offspring,

he may lose a quarter of his body weight.

And that will make surviving winter a very tough prospect indeed.

In autumn's long past, we too had to prepare for the dark months ahead.

For this, we put our faith in some particularly hardy plants.

Plants that already had a strategy for surviving winter.

They may not look much, but these were life-savers.

The mighty kale.

And the sturdy turnip.

# Our day will come (Our day will come)

# And we'll have everything

# We'll share the joy (We'll share the joy)

# Falling in love can bring (Oooh-ooh)

# No-one can tell me that I'm too young to know

# (Young to know)

# I love you so (Love you so)

# And you love me... #

Kale leaves are filled with a natural anti-freeze

and actually taste better after a frost.

While bulb-like turnips will store for months...

..allowing our ancestors to keep calm and carry on.

# Our day will come. #

By the end of harvest, everybody has to have a plan in place.

A Red Admiral gorges on a late fallen plum.

She might well die when the cold strikes,

but she's already laid her eggs

so a new generation will emerge next year.

If you're going to brave it out, now is the time to get busy.

Squirrels are cunning -

hoarding nuts in secret stashes they can return to all winter.

MUSIC: Theme from "The Great Escape"

Swallows have already escaped to the sun.

By now, they are well on their way to South Africa...

..flying over 8,000 miles.

It's a long and risky journey.

Good luck, chaps. Hope to see you next summer.

But perhaps the simplest escape of autumn

is made by this little creature.

A hazel dormouse.

He doesn't bother hoarding food.

Instead, he just eats...

..doubling his tiny body weight to a chubby 40 grams.

When the temperature drops, he takes to his bed,

battens down the hatch...

..and sleeps till April.

Lucky fella.

Late October has always been a time to take stock.

If animals and plants were thriving, we'd have a good year too.

And that was worth a celebration.

Our autumn festivals coincide

with the time of an ancient party to mark the end of harvest.

A time of feasting...

..and lighting fires.

FIRE ROARS

FIREWORKS EXPLODE

By November, the residents of Britain

are braced for the winter ahead.

Britain may look dark and cold to us,

but there's a band of travellers coming in.

For them, this will feel balmy.

GEESE SQUAWK

50,000 barnacle geese - two-thirds of the world population -

are fleeing the freezing Arctic

and flocking to the tiny Scottish island of Islay.

Their appearance is sudden.

So sudden that locals once thought they were hatched

from the barnacles on the sea shore.

In fact, they've flown here from Greenland,

more than 2,000 miles away.

What have they come for?

Britain's glorious grass.

Our tough old grasses are perfectly suited to surviving the cold.

They're still green and tasty.

They eat as much as they can, as fast as they can.

They have five months to prepare for the long flight home.

Come rain, come shine,

they feed and feed and feed.

But they aren't the only visitors.

Every autumn, Britain faces an invasion.

Aberystwyth is the Biarritz of Wales,

if you're a starling.

These aren't local lads.

They're tourists from as far afield as Russia.

And there's millions more like them up and down the country.

They're all drawn here because we're an island nation.

The ocean keeps heat longer than the land, insulating us,

keeping our climate milder and more hospitable than much of Europe.

What's more, as life on land is shutting down,

there's an enormous surge of life in the sea.

Birds are flocking to the coastline,

drawn for something just below the surface.

BIRDS SQUAWK

In their wake come common dolphins,

which, in autumn, really are common.

DOLPHINS SQUEAK

They're following a sudden explosion in the number of fish.

Some of the visitors are giants.

Fin whales follow the dolphins, waiting to steal their food.

Measuring twice the length of a London bus,

only blue whales are bigger.

But why does all this happen now?

It's because of our position on the planet.

In autumn, cold air is sucked down from the Arctic

and meets the warm ocean around us, creating storms.

And November is the stormiest month of all.

THUNDEROUS ROAR OF WAVE

Nutrients, which have lain dormant during summer,

are mixed, like in a washing machine, bringing the ocean to life.

Atlantic depressions create giant waves.

Warm ocean air is sucked onto the cold land, bringing gales and rain.

This is an elemental consequence of the fading sun.

An unsettled time, which some find exhilarating.

Monster waves, so prized by the surfers,

pound our west-facing beaches,

like here, on the Scottish islands of Orkney.

For a baby grey seal, that poses a problem.

Newborn pups can't swim.

This baby needs to fatten up first before she's strong enough

and insulated enough, to deal with the cold, rough sea.

She only has 18 days before mum has to return to sea

to feed for herself.

SEAL PUP GRUNTS

It's a race for mother and pup.

Pups eat the equivalent of six packs of butter a day,

sucking half their mother's body weight in fat-rich milk.

And they'll need all the energy they can.

In this cove, with its sharply shelving beach,

big waves can be deadly.

In a bad year, more than half these pups will be swept away,

never to be seen again.

This year, she's one of the lucky ones.

Breeding at this time of year has its risks,

but it's a risk these seals are prepared to take.

In fact, 40% of the world's grey seal population

breed on Britain's beaches.

In fields and forests all over the country,

preparation for the autumn storms have been going on for weeks.

Have you ever wondered why trees shed their leaves?

Like a ship lowering its sails in rough weather,

they reduce their risk of damage by becoming streamlined.

Sometimes the trees get caught out.

The storms of '87 were so devastating because they came early,

before the leaves had a chance to fall.

This particular oak has got its timing right more than 700 times.

The first autumn its leaves fell,

Crusader knights were riding into battle.

But with more than 1,000 million deciduous trees in Britain,

what happens to all the leaf litter?

It becomes a bounty for the unsung heroes of the forest.

In ancient times, Aristotle called earthworms

"the intestines of the soil" because they recycle

thousands of tonnes of organic matter every autumn.

Believe it or not, there are 25 native species of earthworm

in Britain.

Without them, we would be drowning in debris.

They're not the only residents of the woodland floor

that thrive in autumn.

Fungi emerge from decaying wood, doing their bit to break down

organic matter and return it to the soil.

They're here all year, but this is their moment in the sun.

In Britain, there are eight times more species of fungi

than flowering plants,

and yet who can name more than a handful of them?

A few are poisonous to us

but, to other fungi, they can be deadly.

The porcelain fungus may look delicate,

but it produces a fungicide that annihilates its competitors.

There's no doubt fungi are weird and wonderful,

but they are left standing when compared with another member

of the underworld.

Not a plant, not an animal, but something unique.

A creature so foul, it has been called "the dogs vomit."

Meet the slime mould.

For much of the year, they live as single cells,

but in autumn they come together.

A relentless, shape-shifting, yellow goo,

that scours the forest for bacterial food.

The slime mould eats anything that gets in its path,

devouring mulch and decaying matter.

This blob provides an essential service

in cleaning up our woodlands.

Despite lacking an apparent nose, it hones in on its prey -

a white fungus.

# Now that we've chosen

# To take all we can

# This shade of autumn

# A stale bitter end

# Years of frustration

# Lay down side by side

# And it's only you

# Who can tell me apart

# And it's only you

# Who can turn my wooden heart... #

When all food is gone, they have a trick up their sleeve.

A co-ordinated effort in mass-reproduction.

How this colonial creature determines who does what

is anyone's guess.

Yet, some cells form stems, other cells form spores...

..and the slime mould's tiny cells are scattered.

Ready to spring into action when the good times return.

It's all going on, on the forest floor in autumn -

it's the after-party when the summer show is over.

All these creatures thrive,

because of something that Britain is famous for.

Autumn is the rainiest of all seasons.

On average, more than 30 centimetres of rain

falls between September and November.

And by November, the land is so waterlogged,

the rain has nowhere to go.

The Somerset Levels turn from summer crops...to autumn lakes.

Villages become islands.

Cheddar Gorge, a torrent...

..as rivers across the country, burst their banks.

For one animal,

the rising water levels can't come soon enough.

An Atlantic salmon.

He's prepared for this moment all his life.

Five years ago, he swam down this river to the sea.

The deluge gives him the chance to fight his way back.

He's against the clock - the longer it takes, the weaker he gets.

He hasn't eaten since spring,

and his body is beginning to fall apart.

The shortening days are a sign that his time is nearly up.

At last, he finds what he's come for.

A female.

She has chosen a spot in the river and dug a shallow nest

in which to lay her eggs.

Placing her body to the ground is a sign that she's nearly ready.

As she begins to lay, he fertilises her eggs.

Their job is done.

If you're only going to do it once, you've got to make it count.

10,000 eggs lie scattered on the river bed.

If some survive, he will have achieved his goal.

The male will now grow thin and his energy will fade.

Soon, his remains will fertilise the river, where next year,

his offspring will be born.

His story is the essence of autumn.

Clearing away the old,

and sowing a seed for when the sun returns.

It's December - the darkest month of the year.

Since the September equinox, the sun has dropped in the sky,

giving London just eight hours of natural light each day.

What do we do to get through it?

We fill our lives with light of our own.

It's still three weeks to Christmas,

but we find any excuse to brighten the long, dark nights.

In John o'Groats in Scotland, the 18-hour night offers the perfect

backdrop to nature's very own light display - the aurora borealis.

More than 50 miles above the planet, charged particles,

flowing past the Earth, collide with atoms to form light.

In the far north, December nights are truly long and truly dark,

and that makes it dangerous,

particularly for small birds.

All over the country, they'll do whatever they can

to reduce the risk from nocturnal predators.

In 21st century Britain, there are places where

the long, dark nights of autumn just don't exist.

Heathrow Airport - light 24/7.

As sunset falls, the latest arrivals sneak in under the radar.

They have a reservation - one that that will keep them safe

in the dark and leaf-less nights.

While heat radiating from the glass

and concrete also makes this an unseasonably cosy setting.

Making the most of it, are hundreds of pied wagtails.

Wagtails are usually solitary birds,

so it's hardly surprising each wants his own space.

And nobody wants to sit near the toilet!

With the lights on,

it makes it really tricky for nocturnal predators to sneak up.

Here, the wagtails are safe from hungry owls.

Eventually, any warmth at all is just a distant memory.

Sun-less December allows the serious cold to creep in.

Autumn is over.

Shards of ice form - known as hoarfrost.

This is now a winter wonderland, with very different challenges.

All the weight put on in the autumn feast

will be the difference between life and death now.

For some, the snow can't come soon enough.

A few weeks ago, these ptarmigan were brown,

but the shortening days triggered a fantastic transformation.

This hare took the same gamble -

switching its summer brown fur for white.

Here in the Peak District, his gamble has paid off.

If these mountains were still green, he would be easy prey for a buzzard.

Switching from autumn to winter coat

means the hare is now in his element.

The buzzard will struggle to find food now -

winter's arrival turns the tables for predator and prey.

Christmas - time to wind down

and wait for the new calendar year to begin.

But the Earth has already started a new cycle.

Subtly, since December 22nd,

the days have started to get longer again.

And while it will take many months for the sun's warmth to be felt,

nature feels a change is on the way.

Soon, the first buds will begin to form

and the birds will start to sing.

The promise of new life that happens every year.

The coming and going of the sun affects our country in so many ways.

Giving us our seasons and driving every living thing around us.

Spring, summer, autumn, winter...

there's nothing quite like the Great British year.

We know what our British seasons are meant to be like -

snow-white winters,

springs bursting with new life,

glorious hot summers,

and woodlands rich with autumn colour.

But during the filming of The Great British Year,

the seasons weren't always, well, seasonal.

In recent years, our weather seems unpredictable.

Are our seasons changing?

And is this having an effect on our wildlife?

At the Met Office in Exeter, information about our weather

is collected and interpreted by a team of expert forecasters.

The weather in the UK isn't unpredictable.

What it is, is variable,

and that is because of where we are on the planet.

Britain's weather is influenced by a whole host of factors -

one of which is the jet stream, a fast flowing ribbon of air

where cold and warm air meet, high in the atmosphere.

The position of the jet stream can mean the difference

between a damp December and a snow-covered Christmas.

So it's hard to draw conclusions from the weather

we get in a single year.

To see if our seasons are changing,

means looking at long-term trends in our climate.

Weather is what you get and climate is what you expect.

Weather changes from day to day, from hour to hour.

Climate is all of those changes taken over a long period of time.

Analysis of Britain's climate

is done by the Met Office state-of-the-art super computer.

By making a trillion calculations a second -

equivalent to the processing power of 100,000 home computers -

it analyses present conditions, and uses them to predict

what will happen - short-term, and months and years in the future.

What is actually happening over a long period of time is that

the temperatures, both globally and in UK, are actually rising.

Just because we get a cold year, or a wet year,

or a hot year doesn't mean that we're not seeing the globe warming -

we are seeing the globe warming and our long-term averages do show that.

They show that actually, compared to 1960,

the UK is about half a degree warmer.

Despite some memorable cold snaps,

since the '90s, we've had nine of the ten warmest years on record.

When it rains, it rains heavier.

And flooding is more frequent.

Some would say our weather is getting more extreme.

But how is that affecting the animals and plants of Britain?

There's a whole army of observers who are keeping an eye on that too.

The study of natural seasonal events is called phenology,

and it's something that British people are pretty obsessed by.

Last weekend, I was recording the first butterflies that I'd seen.

It probably shows I'm a bit OCD myself,

I record the family's first rhubarb crumble of the year!

We may not realised it, but we are a nation of amateur phenologists.

We notice the first buds,

return of the migrant birds,

newborn baby animals,

or when we first cut the lawn.

These indicators help paint a picture of seasonal events

going on in the natural world.

We're just fascinated by spring, we're desperate to see it return.

We've been through a winter and we need some

reassurance that the planet hasn't stopped tilting on its axis.

Thousands of people contribute to surveys of seasonal change.

And analysis of those observations is revealing how the plants

and wildlife of Britain are behaving -

not just on a yearly basis, but over decades.

There is a very general trend for spring to be coming earlier,

and you can see that in plants flowering,

you can see that when migrant birds come back, and leafing of trees.

Oaks are budding,

snowdrops flowering,

and fungi fruiting as much as ten days earlier

than they did 50 years ago.

Autumn is coming later,

meaning the growing season is getting longer.

Animals have changed their patterns too.

Frogs are spawning sooner,

birds like black caps, that were once seasonal visitors,

are now seen all year.

The difference may be just a few days,

but does it matter if the timings of these natural events change?

This study is not just interesting because it tells us

spring is getting earlier and autumn later,

but it tells us that species are not changing at the same rate.

That there may be problems with species which rely on one another

not remaining in synchrony.

Birds must synchronise their breeding seasons with

the boom in insects.

If the caterpillars change their timings

in response to earlier springs,

birds could be out of step with their food supplies.

But if everything moves in unison, things will stay in balance.

Can nature tell us anything of seasons past?

Deep in the vaults of the Natural History Museum in London

are 150,000 butterflies and half-a-million moths

collected by naturalists over the last 250 years.

Collectors caught these highly prized specimens

when they were in pristine condition -

and that's very important, as it tells us when they emerged.

The entire collection is being digitized -

to work out how the dates of butterfly emergence in the past

compares with today.

This is the Meadow Brown butterfly, a common species in Britain.

But would have appealed to the collector

as it has a white hind wing.

That's why that specimen was collected.

You can see it was collected in

Banstead, Surrey on 12th August 1956 by EL Bolton.

Because it's got the actual day that it was collected,

it's a very useful specimen.

As they move through the collections,

it's clear that butterflies used to emerge later,

because springs were cooler.

The trend for earlier emergence is getting more rapid

when you compare butterflies from 50 years ago to today.

It's marvellous that we can use the collections that people have

built up over the last 250 years to answer questions

that are concerning people today.

So what will a British year look like in the future?

And what does that mean for our Great British countryside?

In 50-100 years' time, what the Met Office projections are suggesting

is that for the UK we'll see hotter, drier summers

and warmer, wetter winters.

But that's a general trend - we'll still see the extremes within that.

It looks like we can't get away from our variable weather,

but if it's warmer - that will have implications for our countryside.

The countryside will look different in the future.

We'd like to know what those changes are.

We'd rather not it come to us as a shock.

Our place on the planet means we will always be a seasonal nation,

but how different our seasons will be in the future,

nobody can say for sure.

Yet in 50, or 100 years' time - you can guarantee

we British will still be talking about them.