Learning Zone The Great British Year

MUSIC: "Spring" by Vivaldi

MUSIC: "Summer" by Vivaldi

MUSIC: "Autumn" by Vivaldi

MUSIC: "Winter" by Vivaldi

We all love autumn, don't we?

It's the time we celebrate horrible Halloween

and fantastic Fireworks Night!

But autumn means winter is on the way.

And whilst we are having fun,

trees have to get ready for the coming cold snap.

Leaves trap sunlight to make food, in a process called photosynthesis.

But in the winter, there's not enough sun

for them to work properly.

The trees stop making the green chemical called chlorophyll

that catches the sunlight,

and the yellow, brown and red colours underneath begin to show.

They look brilliant.

And as they die and fall off, they are great fun to catch,

kick through and enjoy.

But what happens to them after they have landed on the ground?

Almost 1.5 billion trees

lose their leaves in our country every year.

That's around 25 trees for every person living here.

They drop thousands of tonnes of leaves on the ground.

So how is it that we don't end up buried in leaves?

It's one of nature's secrets.

Every year, a slimy demolition squad springs into action.

This is one of the key members of the squad, the earthworm!

They love the moist leaves because they breathe

through their skins, and their skins need to be wet to work.

In the autumn, they wriggle up from the ground

into the piles of damp autumn leaves...

..to do lots and lots of eating.

They munch their way through the leaves,

breaking them up into smaller pieces.

These then get mixed up with the soil,

making the ground a better place for plants to grow.

Our next demolition agent

looks like something you might eat.

Mushrooms.

They can't make their own food from sunlight,

so they live off things like rotting leaves.

Mushrooms and toadstools spread tiny spores through the air,

like seeds in the wind.

But even if they look good to eat,

you should never pick wild mushrooms.

Some are so poisonous, they could kill even a grown-up.

This is the third

and slimiest member of our leaf demolition squad.

This yellow moving goo is called a slime mould.

One sort is called the scrambled egg slime mould,

and another, the dog vomit!

For most of the year, slime moulds are just tiny blobs,

but in autumn, they gang together

and creep around like a moving carpet.

They haven't got eyes or a nose,

but they are really good at finding food,

like rotting leaves and other moulds.

This yellow mould has found a white one to eat.

It wouldn't be hard to get out of their way, though.

We are watching them speeded up,

but really, slime moulds can only move one millimetre an hour.

So it would take them a whole day and a night

to travel the length of your little finger.

When the food runs out, they use the same trick as mushrooms.

They send lots of tiny spores into the air

to make new slime moulds in other damp places.

So, if you take a trip out to see the autumn leaves this year,

take a bit of extra time to look for the unsung heroes of the autumn.

The slimy demolition squad!

It's spring!

Shoots are shooting up, flowers are bursting out,

and baby animals

are appearing everywhere.

We love seeing them,

but what does it really take to raise a baby animal?

This little bluetit is ready to start a family of baby birds.

He's found the perfect hole for a nest and now he's started singing.

BIRDS SING

In fact, all the birds are singing.

They might look as though they're just enjoying

the nice spring weather, but actually, they're hard at work.

Singing is their way of finding a partner and telling the world

they are going to build a nest and that no-one else is allowed here.

But once they've got their patch sorted, their mission begins.

These birds are called shags. They live on an island near Newcastle.

They build nests out of sticks.

Some collect their own.

But others steal from birds nesting near them.

Sometimes, from right under their beaks!

Other birds make nests out of moss, straw, or even spider webs.

Our little bluetit makes his nest out of feathers

and dried-out plants,

and then it's time for the eggs!

Not chocolate eggs!

Whilst we're having a feast,

the birds are looking after the real eggs,

which is a far more serious business.

The birds heat the eggs up

with the warmth from their tummies.

If the eggs get cold, the chicks inside will die.

For some birds, mum and dad take it in turns to do the egg-sitting.

But sometimes, mums do all the hard work.

Eider duck mums sit on their eggs

without eating for four whole weeks.

They must get very hungry.

It's even harder when it starts to rain.

The birds can get very cold and wet.

Luckily, the bluetit mum laid her eggs

in a nice, cosy tree hole.

Look! The chicks have hatched.

But the hard work is only just starting.

Now they've got to get lots of food

into all those hungry beaks.

But these bluetits have done something really clever.

Like lots of birds, they've timed their eggs to hatch

just as the leaves start to come out on the trees.

But, er, hang on a minute,

baby bluetits don't eat leaves!

Well, there's something else that does eat them.

Caterpillars love munching on the tender new leaves.

And there's something else that likes eating caterpillars.

Baby bluetits!

So, there are lots of caterpillars for the baby birds.

Which is lucky, since each chick

can eat 100 caterpillars every day!

Now you know just how hard animal parents have to work

to keep their babies happy and healthy.