0:00:17 > 0:00:19Wales is not a big country.
0:00:19 > 0:00:24But packed into it is a vast array of different habitats
0:00:24 > 0:00:26and a wealth of wildlife.
0:00:31 > 0:00:35There are not many places in the world where you can walk
0:00:35 > 0:00:40from mountaintop, through moorland, along rivers,
0:00:41 > 0:00:44through woodland,
0:00:44 > 0:00:46on to the sea.
0:00:46 > 0:00:48And all of that in just a few hours.
0:00:48 > 0:00:51My name is Iolo Williams.
0:00:51 > 0:00:54I've lived and worked with wildlife in Wales all my life.
0:00:56 > 0:01:02I want to share my passion for Wales' variety of wildlife with you.
0:01:06 > 0:01:11In this series, I'll be taking all over the country in all weathers.
0:01:11 > 0:01:15I'll be visiting wonderful landscapes.
0:01:15 > 0:01:18I'll be sharing with you the insights I've learned
0:01:18 > 0:01:21on this journey of discovery through Wales.
0:01:33 > 0:01:39In this programme, we'll travel to Pembroke to see red deer and seals.
0:01:39 > 0:01:43To West Wales to see red squirrels.
0:01:43 > 0:01:47In the Brecon Beacons, we'll experience waterfalls,
0:01:47 > 0:01:51amazing cave structures and discover bats.
0:01:51 > 0:01:55We'll go to Glamorgan and Gwent to see nesting hobbies,
0:01:55 > 0:01:57goshawks and some stunning birds.
0:02:01 > 0:02:06For most people, the gateway to South Wales is the Severn Bridge.
0:02:07 > 0:02:10But for this journey I prefer to start from the West.
0:02:10 > 0:02:15It's a fantastic part of Wales with a terrific coastline.
0:02:15 > 0:02:18About five miles off the Pembrokeshire coast
0:02:18 > 0:02:20is the rocky outcrop of South Bishop.
0:02:23 > 0:02:25Beyond is the island of Ramsey.
0:02:25 > 0:02:31A wonderful location and one of the most important reserves in Wales.
0:02:32 > 0:02:34This is as far west as you can come in Wales,
0:02:34 > 0:02:36the wets coast of Ramsey here.
0:02:36 > 0:02:40In a straight line from here you'll head out towards America.
0:02:40 > 0:02:45I like this west coast, it's always got this incredible atmosphere.
0:02:45 > 0:02:49It's like a battle of wits with the hard rock
0:02:49 > 0:02:52and the sea crashing in against it.
0:02:52 > 0:02:57What's nice is there's a seal down in the water having a rough time.
0:02:57 > 0:03:01But it leads in around here to this small bay.
0:03:01 > 0:03:05This is where the grey seals comes to give birth.
0:03:05 > 0:03:08You can see pups and cows on the beach.
0:03:08 > 0:03:12What's interesting is that just off-shore you've got the bull
0:03:12 > 0:03:14with his Roman nose.
0:03:14 > 0:03:18He knows that when the cows come in to give birth
0:03:18 > 0:03:20immediately they come in to season.
0:03:20 > 0:03:22When they leave the calf for the first time
0:03:22 > 0:03:25and venture into the water to have a feed and wash,
0:03:25 > 0:03:27he knows they're ready to mate.
0:03:27 > 0:03:29He's in there straight away.
0:03:29 > 0:03:32The largest concentration of Atlantic grey seals
0:03:32 > 0:03:37in southern Britain come to Ramsey in the autumn to give birth.
0:03:37 > 0:03:43Around 400 white coated pups are born here every year.
0:03:43 > 0:03:46They're born from early September to December,
0:03:46 > 0:03:48but most during early October.
0:03:51 > 0:03:54Each female produces a single pup.
0:03:54 > 0:04:00It'll suckle for around three weeks, trebling its weight in this time.
0:04:03 > 0:04:06The rich milk it receives is over 50% fat
0:04:06 > 0:04:09which helps it build up a reserve of blubber
0:04:09 > 0:04:12and insulates it from the cold sea and provides nourishment for it
0:04:12 > 0:04:15until it learns how to hunt and feed itself.
0:04:20 > 0:04:24As soon as the pup is weaned the females are ready to mate again.
0:04:24 > 0:04:28The bulls know this and are waiting on the shore line.
0:04:34 > 0:04:37The bull is twice as big as a cow
0:04:37 > 0:04:40and the courting technique of a male grey seal
0:04:40 > 0:04:42is not very subtle.
0:04:46 > 0:04:48There isn't a lot of delicacy.
0:04:48 > 0:04:52He waits for a fairly receptive female to get close
0:04:52 > 0:04:54and then he pounces.
0:04:57 > 0:04:59It's a bit on the rough side.
0:05:21 > 0:05:26Once mating has taken place and an egg is fertilised in the female
0:05:26 > 0:05:29the egg isn't implanted in the womb immediately.
0:05:29 > 0:05:34The implantation is delayed until the following spring.
0:05:34 > 0:05:38This ensures the pregnancy occurs during the spring and summer months
0:05:38 > 0:05:42when there's plenty of food in the sea to sustain a pregnant mother.
0:05:42 > 0:05:45Calving, once again, takes place next autumn.
0:05:48 > 0:05:52Seals are not the only big mammals on the island.
0:05:52 > 0:05:56On the land lives one of Ramsey's big surprises.
0:05:59 > 0:06:01A heard of red deer here.
0:06:01 > 0:06:04I'm going around because I don't want to scare them.
0:06:04 > 0:06:07See a couple of big stags there?
0:06:07 > 0:06:10Maybe a dozen or so hinds as well.
0:06:10 > 0:06:12It looks like the Highlands of Scotland.
0:06:12 > 0:06:16You've got the same habitat, the rocky outcrops, the grass
0:06:16 > 0:06:18but it is Ramsey.
0:06:18 > 0:06:22I think this is the successful stag with all the hinds.
0:06:22 > 0:06:25This one is hanging around on the periphery.
0:06:25 > 0:06:29Because the ground here is more fertile than in the Highlands
0:06:29 > 0:06:33the stage tend to be 20% heavier and bigger.
0:06:33 > 0:06:36So they are big, massive, muscular beasts.
0:06:36 > 0:06:41Red deer were introduced to the island around 30 years ago
0:06:41 > 0:06:44as farming stock by the previous owners.
0:06:45 > 0:06:47When the island was sold 20 years ago,
0:06:47 > 0:06:52some of the deer couldn't be caught and were left to roam wild.
0:06:52 > 0:06:55By accident, two benefits have resulted.
0:06:55 > 0:06:59Through their grazing, the deer helped to create
0:06:59 > 0:07:03perfect ground conditions for many of the birds that live here
0:07:03 > 0:07:05such as the chough.
0:07:07 > 0:07:09The herd is very pure stock.
0:07:09 > 0:07:14In many parts of Britain it's thought some of our wild red deer
0:07:14 > 0:07:16may have cross bred with sika deer.
0:07:16 > 0:07:22So herds like these on Ramsey may be important blood lines in future.
0:07:25 > 0:07:29Between Ramsey and the mainland lies a treacherous stretch of water
0:07:29 > 0:07:31called Ramsey Sound.
0:07:31 > 0:07:35The Bitches close to the island is particularly dangerous.
0:07:37 > 0:07:41It's a collection of rocks at and below the sea surface
0:07:41 > 0:07:45which creates big white water rapids on a changing tide.
0:07:48 > 0:07:52Reaching the mainland, you find St David's.
0:07:52 > 0:07:56Founded by the patron saint of Wales during the 6th Century,
0:07:56 > 0:07:58it's Britain's smallest city.
0:07:58 > 0:08:02It's surrounded by farmland and close to one of the most
0:08:02 > 0:08:05beautiful sections of coast in Wales.
0:08:05 > 0:08:08I'm heading to one particular gem in north Pembrokeshire.
0:08:10 > 0:08:14Halfway between Fishguard and Cardigan is Ceibwr Bay.
0:08:14 > 0:08:18It's a quite cove with amazing steep cliffs.
0:08:20 > 0:08:23The rocks have been folded and contorted
0:08:23 > 0:08:27by continental earth movements which occurred about 450 million years ago.
0:08:31 > 0:08:34In the summer, the cliffs are particularly beautiful
0:08:34 > 0:08:37and are covered with wild flowers.
0:08:37 > 0:08:40But the special interest here are housemartins.
0:08:40 > 0:08:44They're nesting as nature intended.
0:08:44 > 0:08:47As a kid we used to have housemartins nesting
0:08:47 > 0:08:49underneath the eaves of the house.
0:08:49 > 0:08:52I used to watch them for hours on end.
0:08:52 > 0:08:56I'd wonder where housemartins nest before we built houses.
0:08:56 > 0:09:00It took me years before I realised that it was on cliffs
0:09:00 > 0:09:02like this one here in Pembrokeshire.
0:09:02 > 0:09:05They'd build their mud nests underneath an overhang
0:09:05 > 0:09:08just like they do in the eaves of our houses.
0:09:08 > 0:09:13Now, in the whole of Wales, there are half as dozen locations
0:09:13 > 0:09:16where they use natural sights like this.
0:09:40 > 0:09:43These housemartins are sourcing their mud from a pool
0:09:43 > 0:09:45by the side of a lane at the top of the cliff.
0:09:45 > 0:09:47If you look carefully,
0:09:47 > 0:09:51you'll see their legs are covered with white feathers.
0:09:52 > 0:09:55There's a theory about this.
0:09:55 > 0:10:00During the winter in Africa, they'll fly 24 hours a day without stopping.
0:10:00 > 0:10:03It's thought they sleep by flying at high altitude.
0:10:03 > 0:10:05They simply doze and glide.
0:10:06 > 0:10:11As it's cold at this altitude, they need feathery legs to keep warm.
0:10:13 > 0:10:17The nest will eventually be in the shape of a bowl
0:10:17 > 0:10:19attached to the cliff.
0:10:20 > 0:10:24This is built up bit by bit with small balls of mud.
0:10:24 > 0:10:29having built up a small portion they bind the mud with grass.
0:10:31 > 0:10:34It'll take them around two weeks to complete
0:10:34 > 0:10:38and having finished the bowl they'll line it with feathers.
0:10:40 > 0:10:42They'll do this pretty much all summer,
0:10:42 > 0:10:45as some of the parents will raise up to three broods
0:10:45 > 0:10:49before heading back to Africa in late September, early October.
0:10:54 > 0:10:57A few miles down the coast from Ceibwr Bay
0:10:57 > 0:10:58is a beautiful estuary.
0:11:00 > 0:11:03This a particular favourite of mine,
0:11:03 > 0:11:07especially at first light during early autumn.
0:11:07 > 0:11:10It's only a small estuary but it's rich in wildlife.
0:11:38 > 0:11:41I've come here to see a special migrant bird
0:11:41 > 0:11:45that's only recently appeared on Welsh estuaries.
0:11:45 > 0:11:48There's a spoonbill and a little egret over here.
0:11:48 > 0:11:50That's interesting.
0:11:50 > 0:11:5520 years ago a little egret would have brought out 400 birdwatchers,
0:11:55 > 0:11:57400 twitchers, here.
0:11:57 > 0:12:00Now, little egrets are common. They're as common as herons here.
0:12:00 > 0:12:02They nest in the areas as well.
0:12:02 > 0:12:04The rare bird now is the spoonbill.
0:12:04 > 0:12:06We get more and more of them into Wales
0:12:06 > 0:12:10and soon, I'm sure, we'll have spoonbills nesting here.
0:12:10 > 0:12:13it makes you think about what's going to be next?
0:12:13 > 0:12:17it's interesting how they're hanging around together.
0:12:17 > 0:12:20At the moment we don't know why they're spreading west.
0:12:20 > 0:12:23We also don't know why the egret numbers have increased
0:12:23 > 0:12:25during the past 20 years.
0:12:25 > 0:12:27It could be a change in climate,
0:12:27 > 0:12:30it could be a habitat change here or on the Continent
0:12:30 > 0:12:32Or a combination of these.
0:12:32 > 0:12:37One thing is clear, our population of bird species is changing.
0:12:37 > 0:12:42It's fascinating with these two brides because they're similar
0:12:42 > 0:12:43but yet they're very different.
0:12:43 > 0:12:47They're both quite big white birds with long legs, long beaks.
0:12:47 > 0:12:50But you watch them feed.
0:12:50 > 0:12:53The little egret has got more of a dagger-like bill.
0:12:53 > 0:12:56He'll walk along and dart out looking for a fish.
0:12:56 > 0:13:01The spoonbill has got this huge, spoon-like bill
0:13:01 > 0:13:02and he just opens it.
0:13:02 > 0:13:06He works his way through the mud and it's hyper sensitive.
0:13:06 > 0:13:08Even though they're in the same spot,
0:13:08 > 0:13:11they're feeding in different ways.
0:13:33 > 0:13:38Soon I'll be having a close encounter with red squirrels
0:13:38 > 0:13:40and fabulous waterfalls.
0:13:42 > 0:13:45But before that I'm heading for the Tywi Valley.
0:13:48 > 0:13:52This section of the River Tywi is between Carmarthen and Llandeilo.
0:13:52 > 0:13:56Here it changes its course along the flat valley bottom
0:13:56 > 0:13:58making it flow in a serpentine way.
0:14:01 > 0:14:03Where you get a wide meander like this
0:14:03 > 0:14:08in some of the bigger Welsh rivers, you often get a shingle bank forming
0:14:08 > 0:14:13on the far side where the river's thrown up pebbles and stone.
0:14:13 > 0:14:17To us it looks quite boring, it looks uniform and flat.
0:14:17 > 0:14:22But it's the perfect nesting site for a handful of specialised birds.
0:14:22 > 0:14:28For one of them, the stronghold in Wales is here on the River Tywi.
0:14:28 > 0:14:31The is a little ringed plover.
0:14:31 > 0:14:36It's a fast little bird, not unlike the cartoon roadrunner character.
0:14:43 > 0:14:47They have striking yellow rings around their eyes.
0:14:47 > 0:14:51Little ringed plovers are only recent migrants to Wales.
0:14:51 > 0:14:56Before the 1960s, they didn't nest here at all.
0:14:56 > 0:15:00In fact, before the 1930s they didn't nest in Britain
0:15:00 > 0:15:04and spread here from Europe to nest in manmade habitats
0:15:04 > 0:15:05mainly gravel pits.
0:15:06 > 0:15:10But in Wales they do it the natural way.
0:15:10 > 0:15:11They use shingle banks.
0:15:14 > 0:15:18They're migrants from Africa and arrive here during March.
0:15:22 > 0:15:26This one is sitting on eggs but they're difficult to see.
0:15:33 > 0:15:36The nest is simply a scrape in the shingle.
0:15:36 > 0:15:41Both the male and the female take turns with the incubation
0:15:41 > 0:15:45and during change over you can make out the nesting eggs.
0:15:55 > 0:15:57In some parts along its coast,
0:15:57 > 0:16:01the Tywi cuts into the land to form high river banks
0:16:01 > 0:16:04and these are ideal nesting sites for another summer visitor.
0:16:07 > 0:16:11They're sand martins and are related to housemartins and swallows.
0:16:11 > 0:16:15But unlike their relatives who build their nests from mud
0:16:15 > 0:16:18these nest by digging holes in riverbanks.
0:16:19 > 0:16:23These big sand martin colonies are impressive places.
0:16:23 > 0:16:27There are maybe 150 holes along the bank here.
0:16:27 > 0:16:30The adult birds are out feeding on the insects above the water
0:16:30 > 0:16:32and above the meadows over there.
0:16:32 > 0:16:35They're back and forth feeding the youngsters.
0:16:35 > 0:16:39The nests are about a metre, two metres up off the ground.
0:16:39 > 0:16:43They go into the bank about a metre so they're safe
0:16:43 > 0:16:46from any passing mink or a fox.
0:16:46 > 0:16:50Really, the biggest threat to the birds is the river itself.
0:16:50 > 0:16:54Although they dig their nests as high as possible above the bank
0:16:54 > 0:16:56rivers can suddenly flood during the summer.
0:16:56 > 0:17:01If that happens, the nests and chicks are washed away.
0:17:01 > 0:17:05Fortunately, this isn't a regular event.
0:17:27 > 0:17:31The Tywi was an important valley for the medieval princes of South Wales.
0:17:31 > 0:17:34There are a number of castles in the area.
0:17:35 > 0:17:37This one is at Dinefwr.
0:17:43 > 0:17:47The castle stands above a park which is surrounded by mature woodland
0:17:47 > 0:17:50and contains some of the oldest trees in Britain.
0:17:50 > 0:17:55There are almost 300 trees here which are over 400 years old.
0:17:56 > 0:18:01But it's also a great place to see fallow deer.
0:18:01 > 0:18:04They were introduced here during medieval times for hunting
0:18:04 > 0:18:07but they've now gone wild.
0:18:07 > 0:18:12In Wales it's mainly a lowland species and all the herds we've got,
0:18:12 > 0:18:14you know some of them are truly wild,
0:18:14 > 0:18:19they all originate from collections from these large estates.
0:18:19 > 0:18:23They would have been walled in in a deer park
0:18:23 > 0:18:27and they would have been hunted centuries ago.
0:18:27 > 0:18:30Gradually some escaped until they're now in woodlands
0:18:30 > 0:18:33throughout much of lowland Wales.
0:18:33 > 0:18:38This herd is still associated with Dinefwr House and Dinefwr Park
0:18:38 > 0:18:39and it's ideal for them.
0:18:39 > 0:18:44They've got open fields and this ancient woodland
0:18:44 > 0:18:47with plenty of ground cover where they can hide.
0:18:47 > 0:18:51There are about 100 fallow deer in the park.
0:18:52 > 0:18:56Only the males have antlers and fallow deer are the only wild deer
0:18:56 > 0:18:59in Britain, which have flat, palm shaped antlers.
0:19:01 > 0:19:04Red and roe deer all have pointed ones.
0:19:06 > 0:19:09You can also identify different species of deer
0:19:09 > 0:19:11by looking at their bottoms.
0:19:13 > 0:19:15The patterns are unique to each species.
0:19:15 > 0:19:19For fallow deer, it's a black stripe with white lines either side
0:19:19 > 0:19:21and black brackets on the outside.
0:19:23 > 0:19:25Even when a deer is moving away from you,
0:19:25 > 0:19:27you can tell what species it is.
0:19:38 > 0:19:4324% of the Welsh uplands is covered with conifer forest.
0:19:47 > 0:19:50This forest lies at the southern tip of the Cambrian Mountains
0:19:50 > 0:19:51near Llandovery.
0:19:51 > 0:19:55It's a very important forest as it's a stronghold for red squirrels.
0:20:00 > 0:20:02Like many other parts of Britain
0:20:02 > 0:20:06red squirrel numbers have declined sharply in Wales.
0:20:06 > 0:20:11They only exist in a handful of locations and are difficult to see.
0:20:11 > 0:20:14I dearly want to see one in the wild.
0:20:14 > 0:20:17Forester, Hugh Denman, manages this forest
0:20:17 > 0:20:21and has been working with red squirrels for many years.
0:20:21 > 0:20:22He had a plan.
0:20:22 > 0:20:26As part of conservation work, Hugh often uses food baits
0:20:26 > 0:20:28to survey the squirrels.
0:20:29 > 0:20:33He's agreed to let me place nuts in a good site for squirrels
0:20:33 > 0:20:35over a period of a few days
0:20:35 > 0:20:38and then wait in a hide to see if one turns up.
0:20:38 > 0:20:42It's going to be critical for us to stay still and quiet.
0:20:42 > 0:20:45They're going to come from the tops of the trees.
0:20:45 > 0:20:47There is food for them up there at the moment.
0:20:47 > 0:20:49The pine cones are ripe
0:20:49 > 0:20:55so it's a matter of tempting them down with the nuts.
0:20:55 > 0:20:58Should I open this or is there enough there?
0:20:58 > 0:21:01Just put a few down, they'll be a lot more attractive.
0:21:01 > 0:21:03Shall I just leave them there!
0:21:03 > 0:21:05I'm sure they'll get in there.
0:21:10 > 0:21:13The hide basically a tent made to look inconspicuous
0:21:13 > 0:21:16with camouflaged patterns and colours.
0:21:16 > 0:21:18It doesn't exactly fit in with the surroundings
0:21:18 > 0:21:21but I'm told it'll work.
0:21:26 > 0:21:29Watching wildlife, especially wild mammals,
0:21:29 > 0:21:31requires a lot of patience.
0:21:31 > 0:21:35But after hours of waiting it arrived.
0:21:39 > 0:21:43The most delightful little creature you'll ever see in Britain.
0:21:56 > 0:21:58This is a real red letter day for me.
0:21:58 > 0:22:01I can't begin to tell you how excited I am.
0:22:01 > 0:22:06This is the first time I've seen a red squirrel in the wild
0:22:06 > 0:22:11in my local patch for 25 years.
0:22:11 > 0:22:12It really is.
0:22:12 > 0:22:17It's probably a red letter day for this squirrel too.
0:22:19 > 0:22:22It won't usually find hazelnuts in this forest.
0:22:22 > 0:22:24Hazel trees don't grow here.
0:22:27 > 0:22:29But it's clearly impressed by them.
0:22:33 > 0:22:38These days red squirrels are confined to conifer plantations.
0:22:38 > 0:22:41Here, their main diet is small pine cone seeds.
0:22:42 > 0:22:45Their competitor, the imported grey squirrel,
0:22:45 > 0:22:47can't eat small seeds as efficiently
0:22:47 > 0:22:51and doesn't survive as well in conifer plantations.
0:22:51 > 0:22:54It tends to stay in deciduouswoodland and parks
0:22:54 > 0:22:57foraging on bigger nuts like acorns and hazel.
0:22:59 > 0:23:03In effect, the red squirrel has been forced out of deciduous woodland
0:23:03 > 0:23:06to live in a habitat where it can compete more successfully.
0:23:08 > 0:23:10I don't think this squirrel can believe its eyes.
0:23:10 > 0:23:13It's carrying them away and burying them in the moss.
0:23:13 > 0:23:16It's only when you get this close
0:23:16 > 0:23:19that you realise they are handsome little animals.
0:23:19 > 0:23:26Their beauty's far more attractive than their alien American cousins.
0:23:27 > 0:23:33This is exactly what a squirrel normally does in the autumn.
0:23:33 > 0:23:38Squirrels don't hibernate, they're active throughout winter
0:23:38 > 0:23:42and need to eat during tough times when the autumn harvest has ended.
0:23:42 > 0:23:45Storing food is one solution to this problem.
0:23:54 > 0:23:58This squirrel is showing fascinating behaviour.
0:23:58 > 0:24:02It seems to check every nut before deciding to store it or not.
0:24:06 > 0:24:09Any old nut won't do.
0:24:29 > 0:24:33We don't know how many red squirrels live in this forest.
0:24:33 > 0:24:38There may even be fewer than 500 squirrels left in Wales.
0:24:38 > 0:24:40That's very sad.
0:24:41 > 0:24:43Let's hope it hangs on here.
0:24:57 > 0:24:59Just south of Llandovery
0:24:59 > 0:25:01you reach the Black Mountain area of West Wales.
0:25:01 > 0:25:06It's an area which eventually becomes the Brecon Beacons.
0:25:07 > 0:25:11Locally, this section is known as Bannau Sir Gaer.
0:25:13 > 0:25:18It's a classic valley gouged out by glaciers during the last ice age.
0:25:22 > 0:25:25As the ice melted and carried rocks and earth away
0:25:25 > 0:25:27it formed a circular landscape.
0:25:31 > 0:25:34The lake feeds the River Sawdde.
0:25:35 > 0:25:37Like many upland rivers in Wales
0:25:37 > 0:25:40it's a great place to see grey wagtails.
0:25:40 > 0:25:44Yes, it does look yellow but it is a grey wagtail.
0:25:44 > 0:25:47The yellow wagtail is yellow all over.
0:25:47 > 0:25:50This species has a grey back.
0:25:53 > 0:25:55The grey wagtail is a common bird in Wales
0:25:55 > 0:25:58and this one is catching insects.
0:25:58 > 0:26:02It likes to stay near rivers especially in the uplands
0:26:02 > 0:26:06as it's the only place here with plenty of insects.
0:26:07 > 0:26:10it packs its beak with as many as it can catch.
0:26:20 > 0:26:24It doesn't always hang on to all of them.
0:26:32 > 0:26:35It's feeding chicks in a nest it has built
0:26:35 > 0:26:38in a hole by the side of a weir.
0:26:38 > 0:26:41It's a great place to hide them.
0:26:46 > 0:26:48It keeps the nest meticulously clean.
0:26:48 > 0:26:52Any droppings are taken away and dropped in the river
0:26:52 > 0:26:55so the smell doesn't attract predators.
0:27:12 > 0:27:16Later, I'll be searching for extraordinary cave structures
0:27:16 > 0:27:18under ground in the Brecon Beacons.
0:27:18 > 0:27:21I'll discover bats in old castle dungeons.
0:27:21 > 0:27:23But first I head to the Neath Valley.
0:27:28 > 0:27:31Just south of the grey wagtail location at Llyn y Fan Fach
0:27:31 > 0:27:35you'll find the upper reaches of the River Neath.
0:27:36 > 0:27:38It's an old industrial area
0:27:38 > 0:27:41which has largely gone back to a natural landscape.
0:27:41 > 0:27:45The hills surrounding Resolven are covered with conifer plantations.
0:27:45 > 0:27:49In these hills a secretive bird comes to visit Wales
0:27:49 > 0:27:51from Africa every summer.
0:27:51 > 0:27:57It's difficult to find, not least because it only comes out at night.
0:27:59 > 0:28:01It nests on the ground
0:28:01 > 0:28:05and even in broad daylight its chick is hard to detect
0:28:05 > 0:28:07unless you're really close to it.
0:28:07 > 0:28:09Even then, it'll hardly move.
0:28:12 > 0:28:14It's a nightjar chick.
0:28:14 > 0:28:18If you're a bird that's decided to nest on the floor
0:28:18 > 0:28:21you've got to be well camouflaged
0:28:21 > 0:28:25and your chicks have to be well camouflaged too.
0:28:25 > 0:28:29There's not a bird in Britain that does that better than the nightjar.
0:28:29 > 0:28:32Just a few centimetres in front of me here
0:28:32 > 0:28:34is a nightjar chick.
0:28:34 > 0:28:39It's nearly nine o'clock at night and the parents are out hunting.
0:28:39 > 0:28:42They've left their chick behind on the floor like this
0:28:42 > 0:28:45completely confident that it's so well camouflaged
0:28:45 > 0:28:50he'll never be found by any passing fox or a badger
0:28:50 > 0:28:52or any predator at all.
0:28:52 > 0:28:59To find a chick like that in an area like this is almost impossible.
0:28:59 > 0:29:03As dusk arrives, the adult nightjar returns to feed its chick.
0:29:06 > 0:29:09The old name for a nightjar is the fern owl.
0:29:09 > 0:29:14They fly like an owl and used to nest among fern on heathland.
0:29:17 > 0:29:22The adults' visit to the nest is brief and the chick comes to life.
0:29:26 > 0:29:29It's being fed insects, mainly moths.
0:29:34 > 0:29:37There are about 200 pairs of nightjars in Wales
0:29:37 > 0:29:40and they're here because of the conifer plantations.
0:29:42 > 0:29:45Over the past 20 years they've increased in number
0:29:45 > 0:29:47as trees were harvested.
0:29:47 > 0:29:51The clear areas are ideal habitats for them.
0:29:51 > 0:29:52They're full of moths and insects
0:29:52 > 0:29:56and proved excellent ground nesting sites.
0:29:59 > 0:30:01The large area of conifer plantations in Wales
0:30:01 > 0:30:04has also benefited a fearsome bird.
0:30:04 > 0:30:08This time the nest is high up in the canopy
0:30:08 > 0:30:11and belongs to a powerful bird of prey.
0:30:12 > 0:30:14These are goshawk chicks.
0:30:14 > 0:30:16At five weeks old, they're about to leave the nest
0:30:16 > 0:30:19and begin their life as immature adults.
0:30:24 > 0:30:28They're exercising their wings ready for their first flights.
0:30:30 > 0:30:34They'll hang around the nest area for a while after fledging
0:30:34 > 0:30:37and they're still being fed by the adults.
0:30:37 > 0:30:39Here's one bringing some food back.
0:30:42 > 0:30:45With the chicks at this age the adults don't hang around for long.
0:30:52 > 0:30:56There's a higher density of breeding goshawks in Wales
0:30:56 > 0:31:00than anywhere else in Britain partly because of the conifer trees
0:31:00 > 0:31:03and partly because they're not persecuted as much in Wales
0:31:03 > 0:31:06as there are few shooting estates.
0:31:06 > 0:31:09They have a bad reputation with gamekeepers.
0:31:09 > 0:31:13They're exceptional predators and will kill and eat many things.
0:31:14 > 0:31:18Their large size gives them power to catch big game birds
0:31:18 > 0:31:20like pheasants and squirrels.
0:31:20 > 0:31:24Nevertheless, they're magnificent birds of prey
0:31:24 > 0:31:26and Wales would be a poorer place without them.
0:31:34 > 0:31:37When people visit South Wales, many head for the Brecon Beacons
0:31:37 > 0:31:40particularly Pen y Fan, the highest peak.
0:31:40 > 0:31:42It's great walking country.
0:31:46 > 0:31:49But most visitors and local alike
0:31:49 > 0:31:52overlook the real hidden treasures of the Beacons.
0:31:52 > 0:31:55They are found at lower levels.
0:31:55 > 0:32:00These are the marshes of Traeth Mawr.
0:32:00 > 0:32:05To walk this landscape at dawn is an experience not to be missed.
0:32:09 > 0:32:11I'm here on a cold April morning.
0:32:11 > 0:32:15It's the beginning of spring and the first hour of daylight
0:32:15 > 0:32:16is alive with birdsong.
0:32:21 > 0:32:24It's a showcase for the fantastic range of small birds
0:32:24 > 0:32:26living in Wales.
0:32:34 > 0:32:37There's a song thrush going away behind me.
0:32:37 > 0:32:43There's a scratchy call here, that's a sedge warbler in from Africa.
0:32:43 > 0:32:45There are skylarks in this grass.
0:32:45 > 0:32:48There's even a pair of curlew over there.
0:32:48 > 0:32:50The willow warbler going away now.
0:32:50 > 0:32:53There's been a cuckoo calling from the hillside over there.
0:32:53 > 0:32:58But the best one of all is in this marshy, wet area here.
0:32:58 > 0:33:00It's a bird called the snipe.
0:33:00 > 0:33:04It has got a call, a tick-tock tick-tock kind of call
0:33:04 > 0:33:09but it also does a display where it doesn't use its beak
0:33:09 > 0:33:11but actually uses its tail.
0:33:11 > 0:33:14It pushes out these two outer tail feathers
0:33:14 > 0:33:19and when it dives down it makes this incredible noise.
0:33:24 > 0:33:26This is the snipe's tick-tack call.
0:33:29 > 0:33:33The snipe is calling from somewhere on the ground.
0:33:34 > 0:33:38It's loud enough to attract a female to its territory.
0:33:38 > 0:33:42And then he displays.
0:33:47 > 0:33:49The movement of wind through the outer tail feathers
0:33:49 > 0:33:51creates a unique noise.
0:34:02 > 0:34:06Without a doubt, one of the most impressive landscapes in South Wales
0:34:06 > 0:34:09is found in the area of the Beacons known as waterfall country,
0:34:09 > 0:34:12west of Merthyr Tydfil.
0:34:18 > 0:34:21In deep, wooded gorges, two tributaries of the Neath
0:34:21 > 0:34:23form fantastic waterfalls.
0:34:27 > 0:34:31The Afon Mellte is fed with water gushing down
0:34:31 > 0:34:32from the Brecon Beacons.
0:34:33 > 0:34:37The Mellte is fed by the Afon Hepste.
0:34:37 > 0:34:40Here too there's a terrific spectacle
0:34:40 > 0:34:43and probably the most spectacular falls of them all.
0:34:44 > 0:34:46It's a fair trek to reach it.
0:34:46 > 0:34:49A good couple of miles from the nearest road.
0:34:49 > 0:34:52It's not particularly easy to find in the thick woodland
0:34:52 > 0:34:54but the effort is well worth it.
0:35:00 > 0:35:02This is one of Wales's hidden gems.
0:35:02 > 0:35:06There's a series of waterfalls going all the way up this valley.
0:35:06 > 0:35:11But my favourite and the only one you can get behind is this one,
0:35:11 > 0:35:13Sgwd yr Eira.
0:35:13 > 0:35:14A beautiful name.
0:35:14 > 0:35:19'Sgwd' means waterfall and 'eira' means snow.
0:35:19 > 0:35:22This is waterfall of snow.
0:35:23 > 0:35:27Waterfalls form when hard rock meets softer rock.
0:35:27 > 0:35:30At the top of the falls lies sandstone.
0:35:31 > 0:35:34At the bottom there's relatively softer mud stone
0:35:34 > 0:35:37from the same geological period but slightly younger.
0:35:37 > 0:35:40This mud stone is continually being eroded away
0:35:40 > 0:35:43dropping lower with time and making the falls taller.
0:35:47 > 0:35:50Sgwd yr Eira, like other waterfalls in the Brecon Beacons,
0:35:50 > 0:35:53have all formed because of this special geology that exist
0:35:53 > 0:35:56in this fantastic area of South Wales.
0:35:58 > 0:36:02The extraordinary nature of the geology in South Wales
0:36:02 > 0:36:06has also led to a spectacular landscape underground.
0:36:06 > 0:36:10Llangattock Mountain is at the south eastern end of the Beacons.
0:36:13 > 0:36:16Like much of the Beacons it's made up of limestone rock
0:36:16 > 0:36:21and because of that, South Wales has Europe's most extensive cave system.
0:36:24 > 0:36:28Martin Farr is one of Britain's leading underground explorers
0:36:28 > 0:36:31and he's taking me to a cave at Daren Cilau,
0:36:31 > 0:36:33a stony outcrop which stands on the mountain
0:36:33 > 0:36:37not far from his home at Crickhowell.
0:36:37 > 0:36:40It looks like you're guiding me into a cliff rather than into a cave.
0:36:40 > 0:36:44Just a vague hint of a path lead into it.
0:36:44 > 0:36:46Not very inspiring.
0:36:46 > 0:36:50The original entrance into Darn Cilau.
0:36:50 > 0:36:52- Not very big, is it?- No.
0:36:52 > 0:36:56We're not going to get in there with a bag on your back.
0:36:56 > 0:36:59Well, right, OK.
0:37:01 > 0:37:05My idea of a cave entrance is something taller than me
0:37:05 > 0:37:06and wider than me.
0:37:06 > 0:37:10That's everybody's dream of a cave but sometimes these are the sizes.
0:37:10 > 0:37:14They're small and we've got to negotiate to get there.
0:37:14 > 0:37:16It's not the most pleasant of caves.
0:37:16 > 0:37:18How old were you when you first went in here?
0:37:18 > 0:37:22I was 13 when I first went to the end of the cave.
0:37:22 > 0:37:27Basically, in those days, it was just a real tight slope.
0:37:27 > 0:37:32You went straight into water, the entrance was half full of water.
0:37:32 > 0:37:35- So you were cold all the way in and all the way out.- Absolutely.
0:37:35 > 0:37:40Today it's nice and calm but there's a subtle breeze blowing
0:37:40 > 0:37:46which for cavers that's what tells us the cave is going somewhere good.
0:37:46 > 0:37:48- Why do you do this? - Because it's fantastic.
0:37:48 > 0:37:52That thrill of perhaps being the first person
0:37:52 > 0:37:56to find some new bit of cave that's never been discovered
0:37:56 > 0:37:59is beyond words, it's absolutely fantastic.
0:37:59 > 0:38:04What Martin failed to mention is it's going to take four hours
0:38:04 > 0:38:07of squeezing through narrow passages and some hard scrambling
0:38:07 > 0:38:09to reach the jewels of the cave.
0:38:09 > 0:38:12I thought this was the easy entrance, Martin.
0:38:12 > 0:38:17And of course, I'm all too aware we have to come back the same way.
0:38:19 > 0:38:23Although difficult to get in I'm assured the effort is worthwhile
0:38:23 > 0:38:25as the views inside are amazing.
0:38:27 > 0:38:32Caves generally only form in rocks that dissolve in water.
0:38:32 > 0:38:35Here, huge limestone blocks have been cut
0:38:35 > 0:38:38by the dissolving action of water making them split
0:38:38 > 0:38:40and fall from the roof of the cave.
0:38:40 > 0:38:43As water seeps through the limestone,
0:38:43 > 0:38:46it also dissolves calcium salts in the rock
0:38:46 > 0:38:48which then reform into calcite formations.
0:38:48 > 0:38:53After thousands of years, these can develop into incredible structures.
0:38:53 > 0:38:56These are the antlers.
0:38:56 > 0:38:58I can see why they're called antlers.
0:38:58 > 0:39:00Look at the size of these two here.
0:39:00 > 0:39:03- These are the largest in the country. - Are they?
0:39:03 > 0:39:08They are growing straight out, not hanging down at all.
0:39:08 > 0:39:11Funny ones here, there's one that looks like a hand,
0:39:11 > 0:39:13there's one going back in on itself.
0:39:13 > 0:39:17- These have got to be hundreds of years old.- Thousands of years old.
0:39:17 > 0:39:22It's a mystery why these formations defy gravity.
0:39:22 > 0:39:25You'd expect the drips to drop vertically not horizontally.
0:39:25 > 0:39:29For some reason these are formed in a different way.
0:39:29 > 0:39:34One suggestion is the effect of wind draughts in the chambers.
0:39:34 > 0:39:37But it's the unknown that make a cave journey
0:39:37 > 0:39:39such a fascinating trip.
0:39:39 > 0:39:43The formations that you see in the different parts of the cave vary
0:39:43 > 0:39:47and are unique to a particular chamber.
0:39:47 > 0:39:50This is urchin oxbow.
0:39:50 > 0:39:54There are fabulous, really small formations here.
0:39:54 > 0:39:57Like delicate little pin cushions.
0:39:57 > 0:40:00It makes sense now. I was wondering why urchin oxbow.
0:40:00 > 0:40:01They look like sea urchins.
0:40:01 > 0:40:05- Pure white sea urchins. - Wow!
0:40:05 > 0:40:10It's only when you're up close, you see how intricate they are.
0:40:19 > 0:40:22This is absolutely stunning. Look at that!
0:40:22 > 0:40:26But this isn't a stalactite, is it?
0:40:26 > 0:40:28The main vertical development is a stalactite.
0:40:28 > 0:40:33The little bits that go out off the side are called helictites.
0:40:33 > 0:40:38After years of searching, finding something like this is magic.
0:40:38 > 0:40:40You can't say anything less.
0:40:40 > 0:40:44Fabulous, unique sites that we've travelled all over the world to see.
0:40:44 > 0:40:48And it's here, in our back garden, as it were.
0:40:48 > 0:40:52I've walked all over Wales and it's a beautiful country.
0:40:52 > 0:40:54I've seen magnificent landscapes.
0:40:54 > 0:40:57But this will rival anything you see on the surface.
0:40:57 > 0:40:59It's fabulous, isn't it?
0:41:11 > 0:41:16Daren Cilau drops 192 metres below Llangattock Mountain
0:41:16 > 0:41:20and currently has 13 miles of known passages.
0:41:20 > 0:41:22Many more are yet to be discovered.
0:41:22 > 0:41:27It's the biggest cave system in the whole of Britain.
0:41:27 > 0:41:32Most don't know this fascinating landscape exists underground
0:41:32 > 0:41:34and few will ever see it first hand.
0:41:43 > 0:41:46A few miles north of Llangattock Mountain is the Grwyney Valley.
0:41:46 > 0:41:48It's not far from Abergavenny.
0:41:50 > 0:41:53It's another upland region covered with conifer plantations.
0:41:55 > 0:42:00Along the Grwyney River, a number of dippers have set up territories.
0:42:01 > 0:42:04Dippers are common on the upland rivers of Wales.
0:42:07 > 0:42:11But on this particular river, there seems to be quite a lot of them.
0:42:12 > 0:42:16A male's territory extends around two miles along the river.
0:42:16 > 0:42:18He'll guard the same nesting site every year
0:42:18 > 0:42:21and pair up with a female to raise chicks.
0:42:25 > 0:42:28It's difficult to tell the male and female apart.
0:42:28 > 0:42:32This pair are collecting insect larvae for their chicks.
0:42:37 > 0:42:41The nest is well hidden by the side of a river.
0:42:47 > 0:42:49See the dipper's nest?
0:42:49 > 0:42:52It's just on the bank over there.
0:42:52 > 0:42:56If the dipper is dependent on the river, so is the nest.
0:42:56 > 0:42:59It's always out over water like this.
0:42:59 > 0:43:02The reason for that is so that the droppings can fall in
0:43:02 > 0:43:04and then be washed away immediately.
0:43:04 > 0:43:08These nests are like a big ball of moss.
0:43:08 > 0:43:12Often under a bridge, but usually on a bank like this.
0:43:12 > 0:43:15And because it's made of moss, it blends in perfectly.
0:43:19 > 0:43:23A dipper is our only small bird that swims underwater to find food
0:43:23 > 0:43:27and collects the insect larvae from the riverbed.
0:43:29 > 0:43:32If the river floods, catching larvae will be a problem.
0:43:32 > 0:43:34It won't be able to see them.
0:43:35 > 0:43:40If that happens, it'll go to less turbulent upland brooks for food.
0:43:41 > 0:43:46That's why they're often seen on upland rivers.
0:43:46 > 0:43:50And this particular site is ideal.
0:43:50 > 0:43:53Here, this pair have access not only to the main river,
0:43:53 > 0:43:55but to a smaller brook.
0:43:55 > 0:43:59And incidentally, nobody knows why they bob up and down.
0:44:00 > 0:44:03But it certainly gives them their name.
0:44:37 > 0:44:40The south-east part of Wales between Brecon and Monmouth
0:44:40 > 0:44:43has a number of small castles.
0:44:46 > 0:44:51These are Norman castles with fortified round keeps.
0:44:54 > 0:44:59They were built for security and to protect Norman land from the Welsh.
0:44:59 > 0:45:02Being Welsh, I'm on my way to the dungeon
0:45:02 > 0:45:04in one of my old foe's buildings.
0:45:07 > 0:45:09I've come here to look for bats.
0:45:09 > 0:45:11Because they're a protected species,
0:45:11 > 0:45:14I'm not allowed to tell you which castle I'm in.
0:45:14 > 0:45:18And, indeed, I have to possess a special licence just to be here.
0:45:20 > 0:45:22This wonderful little animal here
0:45:22 > 0:45:25is a lesser horseshoe bat.
0:45:25 > 0:45:30It's hibernating in the dungeon of a castle, hanging from the stones.
0:45:30 > 0:45:35This is ideal because the temperature down here is constant.
0:45:35 > 0:45:38It doesn't vary. That's because of the thick walls.
0:45:38 > 0:45:42It insulates them from the sun and the extreme cold.
0:45:42 > 0:45:47It's got its wings wrapped around it like brown cling film.
0:45:47 > 0:45:49And what's interesting is that
0:45:49 > 0:45:54I've been asked not to say the letter "s" very often.
0:45:54 > 0:45:58Apparently, they pick up on that and they wake up.
0:45:58 > 0:46:01But you try saying a sentence without the letter "s" in it.
0:46:01 > 0:46:03It's very, very difficult.
0:46:03 > 0:46:05But magnificent little things.
0:46:05 > 0:46:11And so much sophistication packed into one small animal.
0:46:12 > 0:46:16The lesser horseshoe bat is one of our smallest bat species.
0:46:16 > 0:46:20They use their tiny feet to attach to the stone.
0:46:23 > 0:46:27The grip is supported and locked by strong leg tendons.
0:46:28 > 0:46:30And they need to be strong.
0:46:30 > 0:46:34Can you imagine hanging on a cliff without releasing your grip
0:46:34 > 0:46:36for five minutes, let alone a day?
0:46:36 > 0:46:38And not to mention all winter.
0:46:40 > 0:46:42Not all bats hang upside down.
0:46:42 > 0:46:47Some bat species tuck themselves into small cracks and crevices.
0:46:47 > 0:46:50But the lesser horseshoe bat is one species that does.
0:46:52 > 0:46:55They can wrap their wings all around the body and head.
0:46:55 > 0:46:58You can just see an ear pointing out.
0:47:00 > 0:47:02It's now March.
0:47:02 > 0:47:06These bats have another month to go before the end of their hibernation.
0:47:06 > 0:47:10They've been hibernating here in this dungeon since late September.
0:47:10 > 0:47:14As soon as it becomes milder and insects are active,
0:47:14 > 0:47:17these bats will begin to venture out to feed by night.
0:47:18 > 0:47:21Lesser horseshoe bats are found throughout Wales.
0:47:29 > 0:47:31Surprisingly, industrial parts of South Wales
0:47:31 > 0:47:34have come to harbour a fascinating range of birdlife.
0:47:34 > 0:47:37You don't have to travel far to find it,
0:47:37 > 0:47:39if you know where to look.
0:47:40 > 0:47:45Port Talbot is arguably the most industrial landscape in the country.
0:47:45 > 0:47:48And yet, on the heath land above the town
0:47:48 > 0:47:52lives a bird that used to be the rarest bird in Britain.
0:47:54 > 0:47:56It's a Dartford warbler.
0:47:56 > 0:48:00And this male has set up a territory just above the M4.
0:48:04 > 0:48:07Around 50 years ago, there were fewer than 12 in Britain.
0:48:07 > 0:48:10And they all lived in the south-east of England.
0:48:12 > 0:48:15Gradually, they increased in number
0:48:15 > 0:48:18and in South Wales, they've colonised post-industrial land.
0:48:21 > 0:48:23The male will live here for most of the year
0:48:23 > 0:48:26and is attracted to the gorse. It's a good nesting site.
0:48:28 > 0:48:32Dartford warblers also need to live in a relatively mild climate
0:48:32 > 0:48:34where there are insects all year round.
0:48:35 > 0:48:40Port Talbot perfectly serves that need, as it's near the coast.
0:48:46 > 0:48:49There's a breadth of post-industrial sites in South Wales
0:48:49 > 0:48:51with fantastic wildlife.
0:48:52 > 0:48:55This old quarry area south of Cardiff at Cosmeston
0:48:55 > 0:48:58has attracted one of Wales's rarest nesting birds.
0:48:58 > 0:49:03It's a beautiful bird that lives hidden in the reed beds.
0:49:05 > 0:49:07It's a bearded tit.
0:49:07 > 0:49:12This one is a male. The female doesn't have the moustache.
0:49:12 > 0:49:1530 years ago, it didn't exist in Wales.
0:49:15 > 0:49:17As the old industrial land was reclaimed,
0:49:17 > 0:49:20it found the perfect habitat it needed.
0:49:22 > 0:49:27A well-managed reed bed where it can hide and feed.
0:49:27 > 0:49:29And in this case, as it's near the sea,
0:49:29 > 0:49:32a location which has a relatively mild climate.
0:49:33 > 0:49:39During harsh winters, these striking birds simply can't survive.
0:49:44 > 0:49:48Another old industrial site with excellent wildlife
0:49:48 > 0:49:50is Cwm Darran, near Merthyr Tydfil.
0:49:51 > 0:49:54The village of Fochrhiw is at the top of the valley.
0:49:55 > 0:49:58This whole area used to be industrial landscape,
0:49:58 > 0:50:01but all signs of coalmining have now gone.
0:50:01 > 0:50:06It's been transformed to a parkland surrounded by heath.
0:50:06 > 0:50:08And the cuckoo has made it its summer home.
0:50:10 > 0:50:13It's increasingly on the decline in Britain,
0:50:13 > 0:50:15but in the old industrial heartland of South Wales,
0:50:15 > 0:50:17it's found a perfect spot.
0:50:17 > 0:50:19A place to watch birds on the heath.
0:50:25 > 0:50:29And this is what the cuckoo's been looking for.
0:50:29 > 0:50:31It's a meadow pipit nest.
0:50:31 > 0:50:34It's a grass cap with some horsehair in there.
0:50:34 > 0:50:36She's laid two eggs. She's gone off to feed.
0:50:36 > 0:50:39Usually, she lays fours, so she'll lay another one in a bit.
0:50:39 > 0:50:43And it's hidden out of the way beneath the bracken here.
0:50:43 > 0:50:47And the cuckoo has been perching on the pylons down there,
0:50:47 > 0:50:49where she's got a good all-round view of this area.
0:50:49 > 0:50:53All she's doing is waiting for a pipit to leave its nest,
0:50:53 > 0:50:56she'll then dash in, lay an egg in there.
0:50:56 > 0:50:58And the cuckoos that target meadow pipits
0:50:58 > 0:51:02actually make their eggs look like meadow pipit eggs.
0:51:02 > 0:51:06That egg will then hatch, the chick will throw out all the other eggs
0:51:06 > 0:51:10so that the adult meadow pipits just feed that one chick then.
0:51:10 > 0:51:13And because this is a bracken-covered area
0:51:13 > 0:51:16with rushes and a few trees, it's great for meadow pipits
0:51:16 > 0:51:18and brilliant for the cuckoo as well.
0:51:20 > 0:51:25The meadow pipit will do all it can to make it difficult for the cuckoo.
0:51:26 > 0:51:29Once one is detected, it'll be mobbed ceaselessly.
0:51:39 > 0:51:43The pipit will also try to conceal its approach to the nest.
0:51:54 > 0:51:57But inevitably, the cuckoo will succeed.
0:51:57 > 0:52:00It'll manage to lay an egg in the nest.
0:52:01 > 0:52:04The way it mimics the pipit's egg is impressive.
0:52:04 > 0:52:07The cuckoo egg is on the left.
0:52:07 > 0:52:12The only difference is the lack of a darker patch on one end of the egg.
0:52:12 > 0:52:16If you look carefully, you'll find that all the pipit's eggs have it.
0:52:17 > 0:52:20The cuckoo chick inevitably hatches first.
0:52:20 > 0:52:24And it has special claws at the tip of its immature wings
0:52:24 > 0:52:26to enable it to grab the side of the nest
0:52:26 > 0:52:28while injecting the other eggs.
0:52:29 > 0:52:32On the one hand, it's cruel.
0:52:32 > 0:52:35But on the other, essential for the cuckoo's survival.
0:52:41 > 0:52:46The Gwent countryside has the gentlest landscape in South Wales.
0:52:46 > 0:52:49It has rich arable farmland
0:52:49 > 0:52:51which attracts its own specialist wildlife.
0:52:52 > 0:52:55And there's one particular favourite of mine.
0:52:57 > 0:53:00Gwent is a stronghold for the hobby.
0:53:02 > 0:53:06It's a small falcon that comes to Wales during the summer.
0:53:07 > 0:53:09As falcons never build their own nest,
0:53:09 > 0:53:13this one's using an old crow's nest to raise its chicks.
0:53:13 > 0:53:15It has three.
0:53:16 > 0:53:20With the nest site known and a licence obtained to be near it,
0:53:20 > 0:53:24it's an opportunity to observe this elusive bird of prey at close hand.
0:53:25 > 0:53:28Once again, I'm using my inconspicuous tent.
0:53:28 > 0:53:32But this time, armed with a direct video feed from the nest.
0:53:32 > 0:53:35She's coming closer now.
0:53:40 > 0:53:43This is nice. One of the adults has just come in
0:53:43 > 0:53:47very, very briefly, dropped some food on there, has gone off again.
0:53:47 > 0:53:50And two of the chicks, the biggest two,
0:53:50 > 0:53:52they're tucking into it now,
0:53:52 > 0:53:55leaving the youngest one to wait his or her turn.
0:53:55 > 0:53:57These are about three weeks' old.
0:53:57 > 0:54:00So up until now, the adults have landed there,
0:54:00 > 0:54:02they've broken up the prey and fed the youngsters.
0:54:02 > 0:54:04But from now on in, for the next week or so
0:54:04 > 0:54:07when they're in that nest, they just dump the food off
0:54:07 > 0:54:10and they'll feed themselves.
0:54:10 > 0:54:14Hobbies are fantastic birds. They're very agile, manoeuvrable
0:54:14 > 0:54:17and one of the few birds that actively hunt swallows,
0:54:17 > 0:54:20house martins, even swifts.
0:54:20 > 0:54:23But they also feed on large insects like dragonflies, too.
0:54:23 > 0:54:25I couldn't quite make out what that was.
0:54:25 > 0:54:28It probably wasn't an insect. I think it was a bird
0:54:28 > 0:54:32because they're still eating it. Exactly what it was, I don't know.
0:54:33 > 0:54:37The hobby is yet another bird that has only recently colonised Wales.
0:54:37 > 0:54:41Before the 1960s, it didn't nest here at all.
0:54:50 > 0:54:53I end my journey of South Wales near Pontypool.
0:54:54 > 0:54:57This is Llandegfedd reservoir.
0:54:57 > 0:55:00It supplies drinking water to the city of Newport.
0:55:02 > 0:55:05Big water areas like this always attract birds.
0:55:05 > 0:55:07They can see it for miles.
0:55:07 > 0:55:09And this is the best site in Wales
0:55:09 > 0:55:12to see an extraordinary courtship display.
0:55:15 > 0:55:18It's late March.
0:55:18 > 0:55:21A male great crested grebe is courting a female.
0:55:33 > 0:55:37Great crested grebes have the most complex courtship display
0:55:37 > 0:55:39of any Welsh bird.
0:55:41 > 0:55:44There must be a dozen pairs here on the reservoir.
0:55:44 > 0:55:47All in sync with their courtship rituals.
0:55:54 > 0:55:57The elaborate ears only grow during spring.
0:55:57 > 0:56:00The rest of the year, they disappear.
0:56:02 > 0:56:05The headdress is clearly an important part of the display.
0:56:08 > 0:56:11The grebes approach each other and dance.
0:56:24 > 0:56:27Everybody's got their own favourite signs of spring,
0:56:27 > 0:56:30whether it's the first primrose or the first swallow.
0:56:30 > 0:56:34But for me, it's watching great crested grebes
0:56:34 > 0:56:36in their courtship dance.
0:56:36 > 0:56:39There's a pair bin front of me here
0:56:39 > 0:56:43and they've set up territory in this shallow little inlet.
0:56:43 > 0:56:46At the moment, they're indulging with a bit of head shaking.
0:56:46 > 0:56:49They have been parallel swimming.
0:56:49 > 0:56:51And this, more than anything else,
0:56:51 > 0:56:55tells me that spring has finally arrived.
0:57:11 > 0:57:13In the next programme,
0:57:13 > 0:57:17my journey will take me to the uplands of North-East Wales
0:57:17 > 0:57:21to witness the extraordinary behaviour of black grouse.
0:57:21 > 0:57:23Over the Cambrian Mountains of Mid Wales
0:57:23 > 0:57:27to see hen harriers and a wonderful courtship display.
0:57:27 > 0:57:31West to Cardigan Bay to see fantastic lizards.
0:57:32 > 0:57:36I'll be revealing hidden gems at my home patch in Powys.
0:57:38 > 0:57:40I'll see some rare species,
0:57:40 > 0:57:42some elusive ones
0:57:42 > 0:57:47and 20,000 starlings in Aberystwyth.
0:57:48 > 0:57:51It's a journey through the heart of Wales.
0:58:17 > 0:58:19Subtitles by Red Bee Media Ltd
0:58:19 > 0:58:21E-mail subtitling@bbc.co.uk