The Beautiful South Wild Wales

Wales is not a big country.

But packed into it is a vast array of different habitats

and a wealth of wildlife.

There are not many places in the world where you can walk

from mountaintop, through moorland, along rivers,

through woodland,

on to the sea.

And all of that in just a few hours.

My name is Iolo Williams.

I've lived and worked with wildlife in Wales all my life.

I want to share my passion for Wales' variety of wildlife with you.

In this series, I'll be taking all over the country in all weathers.

I'll be visiting wonderful landscapes.

I'll be sharing with you the insights I've learned

on this journey of discovery through Wales.

In this programme, we'll travel to Pembroke to see red deer and seals.

To West Wales to see red squirrels.

In the Brecon Beacons, we'll experience waterfalls,

amazing cave structures and discover bats.

We'll go to Glamorgan and Gwent to see nesting hobbies,

goshawks and some stunning birds.

For most people, the gateway to South Wales is the Severn Bridge.

But for this journey I prefer to start from the West.

It's a fantastic part of Wales with a terrific coastline.

About five miles off the Pembrokeshire coast

is the rocky outcrop of South Bishop.

Beyond is the island of Ramsey.

A wonderful location and one of the most important reserves in Wales.

This is as far west as you can come in Wales,

the wets coast of Ramsey here.

In a straight line from here you'll head out towards America.

I like this west coast, it's always got this incredible atmosphere.

It's like a battle of wits with the hard rock

and the sea crashing in against it.

What's nice is there's a seal down in the water having a rough time.

But it leads in around here to this small bay.

This is where the grey seals comes to give birth.

You can see pups and cows on the beach.

What's interesting is that just off-shore you've got the bull

with his Roman nose.

He knows that when the cows come in to give birth

immediately they come in to season.

When they leave the calf for the first time

and venture into the water to have a feed and wash,

he knows they're ready to mate.

He's in there straight away.

The largest concentration of Atlantic grey seals

in southern Britain come to Ramsey in the autumn to give birth.

Around 400 white coated pups are born here every year.

They're born from early September to December,

but most during early October.

Each female produces a single pup.

It'll suckle for around three weeks, trebling its weight in this time.

The rich milk it receives is over 50% fat

which helps it build up a reserve of blubber

and insulates it from the cold sea and provides nourishment for it

until it learns how to hunt and feed itself.

As soon as the pup is weaned the females are ready to mate again.

The bulls know this and are waiting on the shore line.

The bull is twice as big as a cow

and the courting technique of a male grey seal

is not very subtle.

There isn't a lot of delicacy.

He waits for a fairly receptive female to get close

and then he pounces.

It's a bit on the rough side.

Once mating has taken place and an egg is fertilised in the female

the egg isn't implanted in the womb immediately.

The implantation is delayed until the following spring.

This ensures the pregnancy occurs during the spring and summer months

when there's plenty of food in the sea to sustain a pregnant mother.

Calving, once again, takes place next autumn.

Seals are not the only big mammals on the island.

On the land lives one of Ramsey's big surprises.

A heard of red deer here.

I'm going around because I don't want to scare them.

See a couple of big stags there?

Maybe a dozen or so hinds as well.

It looks like the Highlands of Scotland.

You've got the same habitat, the rocky outcrops, the grass

but it is Ramsey.

I think this is the successful stag with all the hinds.

This one is hanging around on the periphery.

Because the ground here is more fertile than in the Highlands

the stage tend to be 20% heavier and bigger.

So they are big, massive, muscular beasts.

Red deer were introduced to the island around 30 years ago

as farming stock by the previous owners.

When the island was sold 20 years ago,

some of the deer couldn't be caught and were left to roam wild.

By accident, two benefits have resulted.

Through their grazing, the deer helped to create

perfect ground conditions for many of the birds that live here

such as the chough.

The herd is very pure stock.

In many parts of Britain it's thought some of our wild red deer

may have cross bred with sika deer.

So herds like these on Ramsey may be important blood lines in future.

Between Ramsey and the mainland lies a treacherous stretch of water

called Ramsey Sound.

The Bitches close to the island is particularly dangerous.

It's a collection of rocks at and below the sea surface

which creates big white water rapids on a changing tide.

Reaching the mainland, you find St David's.

Founded by the patron saint of Wales during the 6th Century,

it's Britain's smallest city.

It's surrounded by farmland and close to one of the most

beautiful sections of coast in Wales.

I'm heading to one particular gem in north Pembrokeshire.

Halfway between Fishguard and Cardigan is Ceibwr Bay.

It's a quite cove with amazing steep cliffs.

The rocks have been folded and contorted

by continental earth movements which occurred about 450 million years ago.

In the summer, the cliffs are particularly beautiful

and are covered with wild flowers.

But the special interest here are housemartins.

They're nesting as nature intended.

As a kid we used to have housemartins nesting

underneath the eaves of the house.

I used to watch them for hours on end.

I'd wonder where housemartins nest before we built houses.

It took me years before I realised that it was on cliffs

like this one here in Pembrokeshire.

They'd build their mud nests underneath an overhang

just like they do in the eaves of our houses.

Now, in the whole of Wales, there are half as dozen locations

where they use natural sights like this.

These housemartins are sourcing their mud from a pool

by the side of a lane at the top of the cliff.

If you look carefully,

you'll see their legs are covered with white feathers.

There's a theory about this.

During the winter in Africa, they'll fly 24 hours a day without stopping.

It's thought they sleep by flying at high altitude.

They simply doze and glide.

As it's cold at this altitude, they need feathery legs to keep warm.

The nest will eventually be in the shape of a bowl

attached to the cliff.

This is built up bit by bit with small balls of mud.

having built up a small portion they bind the mud with grass.

It'll take them around two weeks to complete

and having finished the bowl they'll line it with feathers.

They'll do this pretty much all summer,

as some of the parents will raise up to three broods

before heading back to Africa in late September, early October.

A few miles down the coast from Ceibwr Bay

is a beautiful estuary.

This a particular favourite of mine,

especially at first light during early autumn.

It's only a small estuary but it's rich in wildlife.

I've come here to see a special migrant bird

that's only recently appeared on Welsh estuaries.

There's a spoonbill and a little egret over here.

That's interesting.

20 years ago a little egret would have brought out 400 birdwatchers,

400 twitchers, here.

Now, little egrets are common. They're as common as herons here.

They nest in the areas as well.

The rare bird now is the spoonbill.

We get more and more of them into Wales

and soon, I'm sure, we'll have spoonbills nesting here.

it makes you think about what's going to be next?

it's interesting how they're hanging around together.

At the moment we don't know why they're spreading west.

We also don't know why the egret numbers have increased

during the past 20 years.

It could be a change in climate,

it could be a habitat change here or on the Continent

Or a combination of these.

One thing is clear, our population of bird species is changing.

It's fascinating with these two brides because they're similar

but yet they're very different.

They're both quite big white birds with long legs, long beaks.

But you watch them feed.

The little egret has got more of a dagger-like bill.

He'll walk along and dart out looking for a fish.

The spoonbill has got this huge, spoon-like bill

and he just opens it.

He works his way through the mud and it's hyper sensitive.

Even though they're in the same spot,

they're feeding in different ways.

Soon I'll be having a close encounter with red squirrels

and fabulous waterfalls.

But before that I'm heading for the Tywi Valley.

This section of the River Tywi is between Carmarthen and Llandeilo.

Here it changes its course along the flat valley bottom

making it flow in a serpentine way.

Where you get a wide meander like this

in some of the bigger Welsh rivers, you often get a shingle bank forming

on the far side where the river's thrown up pebbles and stone.

To us it looks quite boring, it looks uniform and flat.

But it's the perfect nesting site for a handful of specialised birds.

For one of them, the stronghold in Wales is here on the River Tywi.

The is a little ringed plover.

It's a fast little bird, not unlike the cartoon roadrunner character.

They have striking yellow rings around their eyes.

Little ringed plovers are only recent migrants to Wales.

Before the 1960s, they didn't nest here at all.

In fact, before the 1930s they didn't nest in Britain

and spread here from Europe to nest in manmade habitats

mainly gravel pits.

But in Wales they do it the natural way.

They use shingle banks.

They're migrants from Africa and arrive here during March.

This one is sitting on eggs but they're difficult to see.

The nest is simply a scrape in the shingle.

Both the male and the female take turns with the incubation

and during change over you can make out the nesting eggs.

In some parts along its coast,

the Tywi cuts into the land to form high river banks

and these are ideal nesting sites for another summer visitor.

They're sand martins and are related to housemartins and swallows.

But unlike their relatives who build their nests from mud

these nest by digging holes in riverbanks.

These big sand martin colonies are impressive places.

There are maybe 150 holes along the bank here.

The adult birds are out feeding on the insects above the water

and above the meadows over there.

They're back and forth feeding the youngsters.

The nests are about a metre, two metres up off the ground.

They go into the bank about a metre so they're safe

from any passing mink or a fox.

Really, the biggest threat to the birds is the river itself.

Although they dig their nests as high as possible above the bank

rivers can suddenly flood during the summer.

If that happens, the nests and chicks are washed away.

Fortunately, this isn't a regular event.

The Tywi was an important valley for the medieval princes of South Wales.

There are a number of castles in the area.

This one is at Dinefwr.

The castle stands above a park which is surrounded by mature woodland

and contains some of the oldest trees in Britain.

There are almost 300 trees here which are over 400 years old.

But it's also a great place to see fallow deer.

They were introduced here during medieval times for hunting

but they've now gone wild.

In Wales it's mainly a lowland species and all the herds we've got,

you know some of them are truly wild,

they all originate from collections from these large estates.

They would have been walled in in a deer park

and they would have been hunted centuries ago.

Gradually some escaped until they're now in woodlands

throughout much of lowland Wales.

This herd is still associated with Dinefwr House and Dinefwr Park

and it's ideal for them.

They've got open fields and this ancient woodland

with plenty of ground cover where they can hide.

There are about 100 fallow deer in the park.

Only the males have antlers and fallow deer are the only wild deer

in Britain, which have flat, palm shaped antlers.

Red and roe deer all have pointed ones.

You can also identify different species of deer

by looking at their bottoms.

The patterns are unique to each species.

For fallow deer, it's a black stripe with white lines either side

and black brackets on the outside.

Even when a deer is moving away from you,

you can tell what species it is.

24% of the Welsh uplands is covered with conifer forest.

This forest lies at the southern tip of the Cambrian Mountains

near Llandovery.

It's a very important forest as it's a stronghold for red squirrels.

Like many other parts of Britain

red squirrel numbers have declined sharply in Wales.

They only exist in a handful of locations and are difficult to see.

I dearly want to see one in the wild.

Forester, Hugh Denman, manages this forest

and has been working with red squirrels for many years.

He had a plan.

As part of conservation work, Hugh often uses food baits

to survey the squirrels.

He's agreed to let me place nuts in a good site for squirrels

over a period of a few days

and then wait in a hide to see if one turns up.

It's going to be critical for us to stay still and quiet.

They're going to come from the tops of the trees.

There is food for them up there at the moment.

The pine cones are ripe

so it's a matter of tempting them down with the nuts.

Should I open this or is there enough there?

Just put a few down, they'll be a lot more attractive.

Shall I just leave them there!

I'm sure they'll get in there.

The hide basically a tent made to look inconspicuous

with camouflaged patterns and colours.

It doesn't exactly fit in with the surroundings

but I'm told it'll work.

Watching wildlife, especially wild mammals,

requires a lot of patience.

But after hours of waiting it arrived.

The most delightful little creature you'll ever see in Britain.

This is a real red letter day for me.

I can't begin to tell you how excited I am.

This is the first time I've seen a red squirrel in the wild

in my local patch for 25 years.

It really is.

It's probably a red letter day for this squirrel too.

It won't usually find hazelnuts in this forest.

Hazel trees don't grow here.

But it's clearly impressed by them.

These days red squirrels are confined to conifer plantations.

Here, their main diet is small pine cone seeds.

Their competitor, the imported grey squirrel,

can't eat small seeds as efficiently

and doesn't survive as well in conifer plantations.

It tends to stay in deciduouswoodland and parks

foraging on bigger nuts like acorns and hazel.

In effect, the red squirrel has been forced out of deciduous woodland

to live in a habitat where it can compete more successfully.

I don't think this squirrel can believe its eyes.

It's carrying them away and burying them in the moss.

It's only when you get this close

that you realise they are handsome little animals.

Their beauty's far more attractive than their alien American cousins.

This is exactly what a squirrel normally does in the autumn.

Squirrels don't hibernate, they're active throughout winter

and need to eat during tough times when the autumn harvest has ended.

Storing food is one solution to this problem.

This squirrel is showing fascinating behaviour.

It seems to check every nut before deciding to store it or not.

Any old nut won't do.

We don't know how many red squirrels live in this forest.

There may even be fewer than 500 squirrels left in Wales.

That's very sad.

Let's hope it hangs on here.

Just south of Llandovery

you reach the Black Mountain area of West Wales.

It's an area which eventually becomes the Brecon Beacons.

Locally, this section is known as Bannau Sir Gaer.

It's a classic valley gouged out by glaciers during the last ice age.

As the ice melted and carried rocks and earth away

it formed a circular landscape.

The lake feeds the River Sawdde.

Like many upland rivers in Wales

it's a great place to see grey wagtails.

Yes, it does look yellow but it is a grey wagtail.

The yellow wagtail is yellow all over.

This species has a grey back.

The grey wagtail is a common bird in Wales

and this one is catching insects.

It likes to stay near rivers especially in the uplands

as it's the only place here with plenty of insects.

it packs its beak with as many as it can catch.

It doesn't always hang on to all of them.

It's feeding chicks in a nest it has built

in a hole by the side of a weir.

It's a great place to hide them.

It keeps the nest meticulously clean.

Any droppings are taken away and dropped in the river

so the smell doesn't attract predators.

Later, I'll be searching for extraordinary cave structures

under ground in the Brecon Beacons.

I'll discover bats in old castle dungeons.

But first I head to the Neath Valley.

Just south of the grey wagtail location at Llyn y Fan Fach

you'll find the upper reaches of the River Neath.

It's an old industrial area

which has largely gone back to a natural landscape.

The hills surrounding Resolven are covered with conifer plantations.

In these hills a secretive bird comes to visit Wales

from Africa every summer.

It's difficult to find, not least because it only comes out at night.

It nests on the ground

and even in broad daylight its chick is hard to detect

unless you're really close to it.

Even then, it'll hardly move.

It's a nightjar chick.

If you're a bird that's decided to nest on the floor

you've got to be well camouflaged

and your chicks have to be well camouflaged too.

There's not a bird in Britain that does that better than the nightjar.

Just a few centimetres in front of me here

is a nightjar chick.

It's nearly nine o'clock at night and the parents are out hunting.

They've left their chick behind on the floor like this

completely confident that it's so well camouflaged

he'll never be found by any passing fox or a badger

or any predator at all.

To find a chick like that in an area like this is almost impossible.

As dusk arrives, the adult nightjar returns to feed its chick.

The old name for a nightjar is the fern owl.

They fly like an owl and used to nest among fern on heathland.

The adults' visit to the nest is brief and the chick comes to life.

It's being fed insects, mainly moths.

There are about 200 pairs of nightjars in Wales

and they're here because of the conifer plantations.

Over the past 20 years they've increased in number

as trees were harvested.

The clear areas are ideal habitats for them.

They're full of moths and insects

and proved excellent ground nesting sites.

The large area of conifer plantations in Wales

has also benefited a fearsome bird.

This time the nest is high up in the canopy

and belongs to a powerful bird of prey.

These are goshawk chicks.

At five weeks old, they're about to leave the nest

and begin their life as immature adults.

They're exercising their wings ready for their first flights.

They'll hang around the nest area for a while after fledging

and they're still being fed by the adults.

Here's one bringing some food back.

With the chicks at this age the adults don't hang around for long.

There's a higher density of breeding goshawks in Wales

than anywhere else in Britain partly because of the conifer trees

and partly because they're not persecuted as much in Wales

as there are few shooting estates.

They have a bad reputation with gamekeepers.

They're exceptional predators and will kill and eat many things.

Their large size gives them power to catch big game birds

like pheasants and squirrels.

Nevertheless, they're magnificent birds of prey

and Wales would be a poorer place without them.

When people visit South Wales, many head for the Brecon Beacons

particularly Pen y Fan, the highest peak.

It's great walking country.

But most visitors and local alike

overlook the real hidden treasures of the Beacons.

They are found at lower levels.

These are the marshes of Traeth Mawr.

To walk this landscape at dawn is an experience not to be missed.

I'm here on a cold April morning.

It's the beginning of spring and the first hour of daylight

is alive with birdsong.

It's a showcase for the fantastic range of small birds

living in Wales.

There's a song thrush going away behind me.

There's a scratchy call here, that's a sedge warbler in from Africa.

There are skylarks in this grass.

There's even a pair of curlew over there.

The willow warbler going away now.

There's been a cuckoo calling from the hillside over there.

But the best one of all is in this marshy, wet area here.

It's a bird called the snipe.

It has got a call, a tick-tock tick-tock kind of call

but it also does a display where it doesn't use its beak

but actually uses its tail.

It pushes out these two outer tail feathers

and when it dives down it makes this incredible noise.

This is the snipe's tick-tack call.

The snipe is calling from somewhere on the ground.

It's loud enough to attract a female to its territory.

And then he displays.

The movement of wind through the outer tail feathers

creates a unique noise.

Without a doubt, one of the most impressive landscapes in South Wales

is found in the area of the Beacons known as waterfall country,

west of Merthyr Tydfil.

In deep, wooded gorges, two tributaries of the Neath

form fantastic waterfalls.

The Afon Mellte is fed with water gushing down

from the Brecon Beacons.

The Mellte is fed by the Afon Hepste.

Here too there's a terrific spectacle

and probably the most spectacular falls of them all.

It's a fair trek to reach it.

A good couple of miles from the nearest road.

It's not particularly easy to find in the thick woodland

but the effort is well worth it.

This is one of Wales's hidden gems.

There's a series of waterfalls going all the way up this valley.

But my favourite and the only one you can get behind is this one,

Sgwd yr Eira.

A beautiful name.

'Sgwd' means waterfall and 'eira' means snow.

This is waterfall of snow.

Waterfalls form when hard rock meets softer rock.

At the top of the falls lies sandstone.

At the bottom there's relatively softer mud stone

from the same geological period but slightly younger.

This mud stone is continually being eroded away

dropping lower with time and making the falls taller.

Sgwd yr Eira, like other waterfalls in the Brecon Beacons,

have all formed because of this special geology that exist

in this fantastic area of South Wales.

The extraordinary nature of the geology in South Wales

has also led to a spectacular landscape underground.

Llangattock Mountain is at the south eastern end of the Beacons.

Like much of the Beacons it's made up of limestone rock

and because of that, South Wales has Europe's most extensive cave system.

Martin Farr is one of Britain's leading underground explorers

and he's taking me to a cave at Daren Cilau,

a stony outcrop which stands on the mountain

not far from his home at Crickhowell.

It looks like you're guiding me into a cliff rather than into a cave.

Just a vague hint of a path lead into it.

Not very inspiring.

The original entrance into Darn Cilau.

-Not very big, is it?

-No.

We're not going to get in there with a bag on your back.

Well, right, OK.

My idea of a cave entrance is something taller than me

and wider than me.

That's everybody's dream of a cave but sometimes these are the sizes.

They're small and we've got to negotiate to get there.

It's not the most pleasant of caves.

How old were you when you first went in here?

I was 13 when I first went to the end of the cave.

Basically, in those days, it was just a real tight slope.

You went straight into water, the entrance was half full of water.

-So you were cold all the way in and all the way out.

-Absolutely.

Today it's nice and calm but there's a subtle breeze blowing

which for cavers that's what tells us the cave is going somewhere good.

-Why do you do this?

-Because it's fantastic.

That thrill of perhaps being the first person

to find some new bit of cave that's never been discovered

is beyond words, it's absolutely fantastic.

What Martin failed to mention is it's going to take four hours

of squeezing through narrow passages and some hard scrambling

to reach the jewels of the cave.

I thought this was the easy entrance, Martin.

And of course, I'm all too aware we have to come back the same way.

Although difficult to get in I'm assured the effort is worthwhile

as the views inside are amazing.

Caves generally only form in rocks that dissolve in water.

Here, huge limestone blocks have been cut

by the dissolving action of water making them split

and fall from the roof of the cave.

As water seeps through the limestone,

it also dissolves calcium salts in the rock

which then reform into calcite formations.

After thousands of years, these can develop into incredible structures.

These are the antlers.

I can see why they're called antlers.

Look at the size of these two here.

-These are the largest in the country.

-Are they?

They are growing straight out, not hanging down at all.

Funny ones here, there's one that looks like a hand,

there's one going back in on itself.

-These have got to be hundreds of years old.

-Thousands of years old.

It's a mystery why these formations defy gravity.

You'd expect the drips to drop vertically not horizontally.

For some reason these are formed in a different way.

One suggestion is the effect of wind draughts in the chambers.

But it's the unknown that make a cave journey

such a fascinating trip.

The formations that you see in the different parts of the cave vary

and are unique to a particular chamber.

This is urchin oxbow.

There are fabulous, really small formations here.

Like delicate little pin cushions.

It makes sense now. I was wondering why urchin oxbow.

They look like sea urchins.

-Pure white sea urchins.

-Wow!

It's only when you're up close, you see how intricate they are.

This is absolutely stunning. Look at that!

But this isn't a stalactite, is it?

The main vertical development is a stalactite.

The little bits that go out off the side are called helictites.

After years of searching, finding something like this is magic.

You can't say anything less.

Fabulous, unique sites that we've travelled all over the world to see.

And it's here, in our back garden, as it were.

I've walked all over Wales and it's a beautiful country.

I've seen magnificent landscapes.

But this will rival anything you see on the surface.

It's fabulous, isn't it?

Daren Cilau drops 192 metres below Llangattock Mountain

and currently has 13 miles of known passages.

Many more are yet to be discovered.

It's the biggest cave system in the whole of Britain.

Most don't know this fascinating landscape exists underground

and few will ever see it first hand.

A few miles north of Llangattock Mountain is the Grwyney Valley.

It's not far from Abergavenny.

It's another upland region covered with conifer plantations.

Along the Grwyney River, a number of dippers have set up territories.

Dippers are common on the upland rivers of Wales.

But on this particular river, there seems to be quite a lot of them.

A male's territory extends around two miles along the river.

He'll guard the same nesting site every year

and pair up with a female to raise chicks.

It's difficult to tell the male and female apart.

This pair are collecting insect larvae for their chicks.

The nest is well hidden by the side of a river.

See the dipper's nest?

It's just on the bank over there.

If the dipper is dependent on the river, so is the nest.

It's always out over water like this.

The reason for that is so that the droppings can fall in

and then be washed away immediately.

These nests are like a big ball of moss.

Often under a bridge, but usually on a bank like this.

And because it's made of moss, it blends in perfectly.

A dipper is our only small bird that swims underwater to find food

and collects the insect larvae from the riverbed.

If the river floods, catching larvae will be a problem.

It won't be able to see them.

If that happens, it'll go to less turbulent upland brooks for food.

That's why they're often seen on upland rivers.

And this particular site is ideal.

Here, this pair have access not only to the main river,

but to a smaller brook.

And incidentally, nobody knows why they bob up and down.

But it certainly gives them their name.

The south-east part of Wales between Brecon and Monmouth

has a number of small castles.

These are Norman castles with fortified round keeps.

They were built for security and to protect Norman land from the Welsh.

Being Welsh, I'm on my way to the dungeon

in one of my old foe's buildings.

I've come here to look for bats.

Because they're a protected species,

I'm not allowed to tell you which castle I'm in.

And, indeed, I have to possess a special licence just to be here.

This wonderful little animal here

is a lesser horseshoe bat.

It's hibernating in the dungeon of a castle, hanging from the stones.

This is ideal because the temperature down here is constant.

It doesn't vary. That's because of the thick walls.

It insulates them from the sun and the extreme cold.

It's got its wings wrapped around it like brown cling film.

And what's interesting is that

I've been asked not to say the letter "s" very often.

Apparently, they pick up on that and they wake up.

But you try saying a sentence without the letter "s" in it.

It's very, very difficult.

But magnificent little things.

And so much sophistication packed into one small animal.

The lesser horseshoe bat is one of our smallest bat species.

They use their tiny feet to attach to the stone.

The grip is supported and locked by strong leg tendons.

And they need to be strong.

Can you imagine hanging on a cliff without releasing your grip

for five minutes, let alone a day?

And not to mention all winter.

Not all bats hang upside down.

Some bat species tuck themselves into small cracks and crevices.

But the lesser horseshoe bat is one species that does.

They can wrap their wings all around the body and head.

You can just see an ear pointing out.

It's now March.

These bats have another month to go before the end of their hibernation.

They've been hibernating here in this dungeon since late September.

As soon as it becomes milder and insects are active,

these bats will begin to venture out to feed by night.

Lesser horseshoe bats are found throughout Wales.

Surprisingly, industrial parts of South Wales

have come to harbour a fascinating range of birdlife.

You don't have to travel far to find it,

if you know where to look.

Port Talbot is arguably the most industrial landscape in the country.

And yet, on the heath land above the town

lives a bird that used to be the rarest bird in Britain.

It's a Dartford warbler.

And this male has set up a territory just above the M4.

Around 50 years ago, there were fewer than 12 in Britain.

And they all lived in the south-east of England.

Gradually, they increased in number

and in South Wales, they've colonised post-industrial land.

The male will live here for most of the year

and is attracted to the gorse. It's a good nesting site.

Dartford warblers also need to live in a relatively mild climate

where there are insects all year round.

Port Talbot perfectly serves that need, as it's near the coast.

There's a breadth of post-industrial sites in South Wales

with fantastic wildlife.

This old quarry area south of Cardiff at Cosmeston

has attracted one of Wales's rarest nesting birds.

It's a beautiful bird that lives hidden in the reed beds.

It's a bearded tit.

This one is a male. The female doesn't have the moustache.

30 years ago, it didn't exist in Wales.

As the old industrial land was reclaimed,

it found the perfect habitat it needed.

A well-managed reed bed where it can hide and feed.

And in this case, as it's near the sea,

a location which has a relatively mild climate.

During harsh winters, these striking birds simply can't survive.

Another old industrial site with excellent wildlife

is Cwm Darran, near Merthyr Tydfil.

The village of Fochrhiw is at the top of the valley.

This whole area used to be industrial landscape,

but all signs of coalmining have now gone.

It's been transformed to a parkland surrounded by heath.

And the cuckoo has made it its summer home.

It's increasingly on the decline in Britain,

but in the old industrial heartland of South Wales,

it's found a perfect spot.

A place to watch birds on the heath.

And this is what the cuckoo's been looking for.

It's a meadow pipit nest.

It's a grass cap with some horsehair in there.

She's laid two eggs. She's gone off to feed.

Usually, she lays fours, so she'll lay another one in a bit.

And it's hidden out of the way beneath the bracken here.

And the cuckoo has been perching on the pylons down there,

where she's got a good all-round view of this area.

All she's doing is waiting for a pipit to leave its nest,

she'll then dash in, lay an egg in there.

And the cuckoos that target meadow pipits

actually make their eggs look like meadow pipit eggs.

That egg will then hatch, the chick will throw out all the other eggs

so that the adult meadow pipits just feed that one chick then.

And because this is a bracken-covered area

with rushes and a few trees, it's great for meadow pipits

and brilliant for the cuckoo as well.

The meadow pipit will do all it can to make it difficult for the cuckoo.

Once one is detected, it'll be mobbed ceaselessly.

The pipit will also try to conceal its approach to the nest.

But inevitably, the cuckoo will succeed.

It'll manage to lay an egg in the nest.

The way it mimics the pipit's egg is impressive.

The cuckoo egg is on the left.

The only difference is the lack of a darker patch on one end of the egg.

If you look carefully, you'll find that all the pipit's eggs have it.

The cuckoo chick inevitably hatches first.

And it has special claws at the tip of its immature wings

to enable it to grab the side of the nest

while injecting the other eggs.

On the one hand, it's cruel.

But on the other, essential for the cuckoo's survival.

The Gwent countryside has the gentlest landscape in South Wales.

It has rich arable farmland

which attracts its own specialist wildlife.

And there's one particular favourite of mine.

Gwent is a stronghold for the hobby.

It's a small falcon that comes to Wales during the summer.

As falcons never build their own nest,

this one's using an old crow's nest to raise its chicks.

It has three.

With the nest site known and a licence obtained to be near it,

it's an opportunity to observe this elusive bird of prey at close hand.

Once again, I'm using my inconspicuous tent.

But this time, armed with a direct video feed from the nest.

She's coming closer now.

This is nice. One of the adults has just come in

very, very briefly, dropped some food on there, has gone off again.

And two of the chicks, the biggest two,

they're tucking into it now,

leaving the youngest one to wait his or her turn.

These are about three weeks' old.

So up until now, the adults have landed there,

they've broken up the prey and fed the youngsters.

But from now on in, for the next week or so

when they're in that nest, they just dump the food off

and they'll feed themselves.

Hobbies are fantastic birds. They're very agile, manoeuvrable

and one of the few birds that actively hunt swallows,

house martins, even swifts.

But they also feed on large insects like dragonflies, too.

I couldn't quite make out what that was.

It probably wasn't an insect. I think it was a bird

because they're still eating it. Exactly what it was, I don't know.

The hobby is yet another bird that has only recently colonised Wales.

Before the 1960s, it didn't nest here at all.

I end my journey of South Wales near Pontypool.

This is Llandegfedd reservoir.

It supplies drinking water to the city of Newport.

Big water areas like this always attract birds.

They can see it for miles.

And this is the best site in Wales

to see an extraordinary courtship display.

It's late March.

A male great crested grebe is courting a female.

Great crested grebes have the most complex courtship display

of any Welsh bird.

There must be a dozen pairs here on the reservoir.

All in sync with their courtship rituals.

The elaborate ears only grow during spring.

The rest of the year, they disappear.

The headdress is clearly an important part of the display.

The grebes approach each other and dance.

Everybody's got their own favourite signs of spring,

whether it's the first primrose or the first swallow.

But for me, it's watching great crested grebes

in their courtship dance.

There's a pair bin front of me here

and they've set up territory in this shallow little inlet.

At the moment, they're indulging with a bit of head shaking.

They have been parallel swimming.

And this, more than anything else,

tells me that spring has finally arrived.

In the next programme,

my journey will take me to the uplands of North-East Wales

to witness the extraordinary behaviour of black grouse.

Over the Cambrian Mountains of Mid Wales

to see hen harriers and a wonderful courtship display.

West to Cardigan Bay to see fantastic lizards.

I'll be revealing hidden gems at my home patch in Powys.

I'll see some rare species,

some elusive ones

and 20,000 starlings in Aberystwyth.

It's a journey through the heart of Wales.

Subtitles by Red Bee Media Ltd

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