0:00:01 > 0:00:05This is the wildest, most remote part of the British Isles.
0:00:05 > 0:00:08It's called St Kilda.
0:00:10 > 0:00:12A handful of rocks out in the Atlantic Ocean
0:00:12 > 0:00:15over 100 miles from the mainland,
0:00:15 > 0:00:17it's the most secret place in Britain.
0:00:21 > 0:00:27Home to sea birds and seals, these islands are also a place of mystery.
0:00:27 > 0:00:30Until just 80 years ago,
0:00:30 > 0:00:33St Kilda was inhabited by a race of people
0:00:33 > 0:00:37who lived in an extraordinary way.
0:00:37 > 0:00:40But when they suddenly abandoned their homes,
0:00:40 > 0:00:44they left behind a place full of secrets.
0:00:44 > 0:00:48St Kilda is Britain's very own Lost World.
0:00:50 > 0:00:55Today, historian Dan Snow, naturalist Steve Backshall
0:00:55 > 0:00:57and me, Kate Humble, are going to venture there
0:00:57 > 0:01:03to explore, to experience and to unravel the secrets of St Kilda.
0:01:04 > 0:01:06It's been a tough assignment.
0:01:06 > 0:01:10But we've already found out about where the St Kildans lived,
0:01:10 > 0:01:13the extraordinary way they caught the sea birds...
0:01:13 > 0:01:17This is a really effective way of moving around the rock face!
0:01:17 > 0:01:20'..and just how precarious their lives were here.
0:01:22 > 0:01:26'We've traced human settlement back to the Vikings
0:01:27 > 0:01:30'and seen how St Kilda's favourite resident is faring...'
0:01:30 > 0:01:33Oh, look at you, little thing!
0:01:33 > 0:01:36'..but there's so much more to discover.'
0:01:36 > 0:01:39Our expedition continues. We're going to be going further,
0:01:39 > 0:01:44exploring where few people have been before on these remote, stunning islands.
0:01:46 > 0:01:49'We'll be diving into St Kilda's stormy seas,
0:01:51 > 0:01:54'discovering Britain's most secretive bird...'
0:01:54 > 0:01:56- Yep, can you see?- Ah-ha, yes!
0:01:56 > 0:01:59- Go! - '..doing the St Kilda Challenge...'
0:02:00 > 0:02:03Here's Dan! Come on, Dan!
0:02:03 > 0:02:07'..and taking on the island's most dangerous intruder...'
0:02:07 > 0:02:09Oohh!
0:02:09 > 0:02:13'..all to unlock the secrets of Britain's lost world.'
0:02:27 > 0:02:29'Welcome to Camp St Kilda,
0:02:29 > 0:02:32'three little tents perched on a hillside
0:02:32 > 0:02:34'on Britain's most remote island.'
0:02:38 > 0:02:42Come on, Kate, time to get up. I'm going to put some porridge on.
0:02:45 > 0:02:46Look at you, Mrs Beeton!
0:02:49 > 0:02:53- HE SIGHS - Hey, dude?- I'm all right.
0:02:53 > 0:02:56Another day in paradise.
0:02:56 > 0:02:57'We're nearly halfway through our mission.
0:02:57 > 0:03:03'But there are still many mysteries to solve, both ancient and more modern.'
0:03:03 > 0:03:06Ohhh! What a beautiful day!
0:03:08 > 0:03:14In 1930, St Kilda was abandoned by the people who lived here.
0:03:16 > 0:03:22Since then, this cluster of rocky islands has become a dual World Heritage Site,
0:03:22 > 0:03:27not only for its history, but also for its astonishing wildlife.
0:03:31 > 0:03:37It's watched over by the handful of National Trust experts who spend their summers here.
0:03:38 > 0:03:41It's like a place that time forgot,
0:03:41 > 0:03:45left to the birds, the wind and the wildlife.
0:03:46 > 0:03:52But how is St Kilda's wildlife surviving in the 21st century?
0:03:54 > 0:03:58'We've already explored the flourishing gannet colony.
0:03:58 > 0:04:02'Now I want to see how St Kilda's marine life is doing.'
0:04:02 > 0:04:04- Hi, how are you doing?- Hi.
0:04:04 > 0:04:06'So I'm heading out to sea.'
0:04:09 > 0:04:13The waters around St Kilda are rich in wildlife.
0:04:13 > 0:04:17Throughout the year, you might see large mammals like minke whales,
0:04:17 > 0:04:20porpoises and dolphins,
0:04:22 > 0:04:24and North Atlantic grey seals.
0:04:24 > 0:04:30But for my dive I'm aiming for some of the smaller delights on offer.
0:04:30 > 0:04:33I'm joining marine biologist Dr Graham Saunders
0:04:33 > 0:04:39on our specialist dive boat, and we're hoping to see some real gems.
0:04:39 > 0:04:41- Graham...- Hi, Kate.- How are you?
0:04:41 > 0:04:44- I'm fine, I'm fine.- Good. You've been looking at the map?
0:04:44 > 0:04:48Well, given the conditions, the fact that this is rather an exposed area...
0:04:48 > 0:04:53- Yeah.- ..as you probably know...we're probably going to go in somewhere along here,
0:04:53 > 0:04:57because the wind will, as normal, cause a problem if we were out on the west side.
0:04:57 > 0:04:59- OK.- So, here's Village Bay...- Yeah.
0:04:59 > 0:05:01- ..and here's a place called Sorca. - Right...
0:05:01 > 0:05:08'Because the waters around St Kilda are so rough, very few marine surveys have been carried out here.'
0:05:08 > 0:05:12I mean, you've done an awful lot of surveying
0:05:12 > 0:05:15of marine life around the west and north coast of Scotland,
0:05:15 > 0:05:17but you've never made it here before, I gather.
0:05:17 > 0:05:21I've tried, I've tried to get here, this is my fourth time.
0:05:21 > 0:05:26The other three times I got almost halfway here, the weather came in, and I was turned back.
0:05:26 > 0:05:31Now as far as wildlife in, as you say, a really exposed,
0:05:31 > 0:05:34remote little archipelago that we have here...
0:05:34 > 0:05:36I mean, do you imagine it's gonna be very different
0:05:36 > 0:05:41from what you'd normally see, say, on the west coast, when you're surveying?
0:05:41 > 0:05:44We are getting some of the benefit from the North Atlantic drift,
0:05:44 > 0:05:47so the water is marginally warmer,
0:05:47 > 0:05:52but it does mean that some of the species that would normally inhabit the northern areas
0:05:52 > 0:05:54are just about starting to get in down here,
0:05:54 > 0:05:59whereas some of the southern species from way down to southern England
0:05:59 > 0:06:01and even as far down as the Mediterranean...
0:06:01 > 0:06:03- Yeah.- ..penetrate up here too.
0:06:03 > 0:06:07'Graham specialises in some of the smallest forms of sea life,
0:06:07 > 0:06:11'and that's what we're hoping to photograph on our dive down.
0:06:11 > 0:06:14'But while we've been inside the ship's cabin,
0:06:14 > 0:06:17'the weather has got worse.
0:06:17 > 0:06:23'As our skipper moves us into position, it's clear how much the swell has picked up.
0:06:24 > 0:06:28'It shows how fast conditions can change out here.
0:06:30 > 0:06:35'If we don't dive now, this could be failed attempt number four for Graham.
0:06:37 > 0:06:41'In water this cold, there's a lot more gear to get used to,
0:06:41 > 0:06:45'not to mention the equipment needed to photograph the sea creatures.'
0:06:45 > 0:06:48AIR HISSES
0:06:49 > 0:06:55'With the swell increasing, after one last safety briefing it's time to get us into the water.
0:06:58 > 0:07:01'Graham and our cameraman safely take the plunge.'
0:07:10 > 0:07:12Have you got it?
0:07:15 > 0:07:19'But just as I'm about to step off, our safety man stops me.'
0:07:19 > 0:07:20Hold on, hold on!
0:07:20 > 0:07:24'The strong current has already swept our cameraman off course,
0:07:24 > 0:07:28'and it could be too dangerous for us to dive in these conditions.
0:07:29 > 0:07:34'It's pretty nerve-racking, but we'll have to reset and give it one more go.'
0:07:40 > 0:07:46'Life on St Kilda has always been dominated by the wild, changeable weather.
0:07:46 > 0:07:52'There are reports of islanders left deaf for days due to the noise of the storm winds and waves,
0:07:52 > 0:07:54'it could be that ferocious.
0:07:54 > 0:07:59'Often trapped in their houses for weeks while winter storms savaged the island,
0:07:59 > 0:08:03'the entire village was once destroyed in a gale.'
0:08:05 > 0:08:09The wind's getting up a bit. I think we're reaching the point
0:08:09 > 0:08:14at which this slope turns into one of the biggest sea cliffs in the UK, so be careful.
0:08:16 > 0:08:21'The islands are battered by the weather rolling in off the Atlantic,
0:08:21 > 0:08:23'but they make their own weather too.
0:08:23 > 0:08:27'When sea air hits these cliffs, it creates a micro-climate.
0:08:27 > 0:08:31'Average rainfall here is double that of the mainland.'
0:08:44 > 0:08:46SEA BIRDS CALL
0:08:54 > 0:08:58Pretty much the most extreme weather in the British Isles up here.
0:08:58 > 0:09:05The wind, although there's not much blowing today, about two or three knots of wind today,
0:09:05 > 0:09:11can get up to... The highest recorded wind speed was 140mph, it's absolutely unimaginable.
0:09:11 > 0:09:14That kind of wind would simply pick me up and blow me off this cliff.
0:09:14 > 0:09:18And frequently, sheep do get blown off the cliff.
0:09:18 > 0:09:24The St Kildans actually got pretty good at forecasting the weather. I mean, their lives depended on it.
0:09:24 > 0:09:27They'd look at where the birds migrated on the island, to give them hints
0:09:27 > 0:09:30about where the next weather front might be coming from.
0:09:30 > 0:09:33Also by looking at the sea, of course...
0:09:33 > 0:09:37Big, crashing waves on the east side of the bay here mean bad weather,
0:09:37 > 0:09:39even if the weather is fair.
0:09:39 > 0:09:44But waves crashing on that beach means it'll probably stay fair.
0:09:44 > 0:09:47So today, looks like something might be brewing.
0:09:58 > 0:10:00We've got our cameraman safely back on board
0:10:00 > 0:10:06and are about to give diving another go before the weather gets even worse.
0:10:06 > 0:10:08- HOOTER BLASTS - OK...
0:10:11 > 0:10:16A big swell above water usually means strong currents down below.
0:10:16 > 0:10:19This could be tough going.
0:10:29 > 0:10:32Graham and I are particularly looking for any species
0:10:32 > 0:10:37that might show if the waters here are getting warmer due to climate change.
0:10:42 > 0:10:46Even on a day like this the waters are exceptionally clear.
0:10:52 > 0:10:56Dense kelp forests loom out from the depths,
0:10:56 > 0:10:59beckoning us towards the steep underwater cliffs of Doune.
0:11:09 > 0:11:13But as we get closer into the narrow gully, the conditions worsen,
0:11:13 > 0:11:18throwing us back and forth, making any work here almost impossible.
0:11:18 > 0:11:24So we have to get deeper, under the cliff face, and away from the swell.
0:11:24 > 0:11:30Then we can steady ourselves and get our first glimpse of what St Kilda has to offer.
0:11:47 > 0:11:51It's astonishing to think that such delicate sea life can exist
0:11:51 > 0:11:54miles out in the wilds of the Atlantic.
0:12:04 > 0:12:09But it's really hard work struggling to stay steady in these currents.
0:12:09 > 0:12:13That means we're using up air at a faster rate than usual,
0:12:13 > 0:12:15so we have to go up earlier than planned.
0:12:29 > 0:12:32We surface some distance from where we started.
0:12:32 > 0:12:38All I can think about now is getting out of the strong currents and safely on board.
0:12:42 > 0:12:46A lot of swell, a lot of surge... Hopeless!
0:12:46 > 0:12:50The expression commonly used is "like being in a washing machine",
0:12:50 > 0:12:53- and it WAS just like being in a washing machine.- It was just hell!
0:12:53 > 0:12:59'It's time to dry off and look at the pictures we've taken.
0:12:59 > 0:13:01'Did we manage to film anything unusual,
0:13:01 > 0:13:05'or did the conditions simply make it too difficult?'
0:13:05 > 0:13:09I was quite surprised, because you sort of look and think it all looks
0:13:09 > 0:13:15like that slightly sort of blotchy kind of algae and small seaweed.
0:13:15 > 0:13:19But when you start to look, there are some real jewels there, aren't there?
0:13:19 > 0:13:22Yes, there are. Just underneath the kelp you'll see
0:13:22 > 0:13:27that the rock itself is absolutely covered in life.
0:13:27 > 0:13:31Look! You get a real sense that we are being battered about there.
0:13:31 > 0:13:35These poor anemones are being absolutely walloped by the surge.
0:13:35 > 0:13:38Everything is flying about.
0:13:38 > 0:13:42Almost everything here is actually adapted for just hanging on.
0:13:42 > 0:13:49Right. This is where I saw this fantastic nudibranch, this sea slug,
0:13:49 > 0:13:52that was very inconveniently (a) exactly the same colour as the kelp,
0:13:52 > 0:13:54and (b) right in amongst it,
0:13:54 > 0:14:00so all those fronds were passing right in front of it.
0:14:00 > 0:14:05- It IS like a dragon. I know you think I'm mad, but look, it just sort of...- Yeah.
0:14:05 > 0:14:09And that weird, spirally shell on there...
0:14:09 > 0:14:15'This little beauty turns out to be a sea hare with a rather unusual visible shell.'
0:14:15 > 0:14:17I'm really pleased with that find.
0:14:17 > 0:14:20I did spend quite a lot of time just trying to get some nice shots
0:14:20 > 0:14:24of the jewel anemones, just because they are so colourful.
0:14:24 > 0:14:31They're beautiful. I think people just don't expect to have that sort of colour in cold water,
0:14:31 > 0:14:36in British seas, but there's a lot of really beautiful stuff down there.
0:14:36 > 0:14:37That is a southern species,
0:14:37 > 0:14:42but it's made its way up here and we see them in large numbers up here.
0:14:42 > 0:14:46Would you say that's an indication of a warming sea,
0:14:46 > 0:14:49as something that's symptomatic of climate change,
0:14:49 > 0:14:53or is it because St Kilda is on the North Atlantic Drift, you've got these warmer seas,
0:14:53 > 0:14:57you can have these southern species existing happily up here?
0:14:57 > 0:15:00- Yeah, I think the latter there is the correct one.- Right.
0:15:00 > 0:15:05The water is relatively warm here, the North Atlantic Drift.
0:15:05 > 0:15:07And so these kind of anemones proliferate.
0:15:07 > 0:15:10'So from the species we saw,
0:15:10 > 0:15:15'it seems that St Kilda's amazing underwater wildlife is thriving.'
0:15:23 > 0:15:28These remote islands are a treasure-trove of history as well as wildlife.
0:15:28 > 0:15:34Because St Kilda has been almost abandoned for 80 years, it's like an archaeologist's dream.
0:15:34 > 0:15:39Relics of the past lie untouched, and just waiting to be discovered.
0:15:39 > 0:15:45During the Second World War, no less than three Allied planes crashed on St Kilda.
0:15:45 > 0:15:48I've come to Glen Mhor, on the north side of Hirta,
0:15:48 > 0:15:52to try and work out what happened in one specific case.
0:15:52 > 0:15:54The night of 7th June 1944,
0:15:54 > 0:16:00ten crewmen were flying their Sunderland flying boat on a training exercise,
0:16:00 > 0:16:03and it crashed here on St Kilda.
0:16:03 > 0:16:07Now the interesting thing about it is that other Second World War planes crashed all the time,
0:16:07 > 0:16:11but their wrecks were immediately picked apart by souvenir hunters and so on.
0:16:11 > 0:16:15But here on St Kilda, it's so isolated - no-one was living here at the time -
0:16:15 > 0:16:20large parts of this wreckage are supposed to be in this valley here.
0:16:20 > 0:16:24As you'd expect, lots of wreckage I think rolled down the hill
0:16:24 > 0:16:29and congregated towards the bottom of that glen, so I'm gonna head down there.
0:16:33 > 0:16:37Nobody knows exactly why this Sunderland flying boat crashed here.
0:16:37 > 0:16:41If I study the pattern of the wreckage, maybe I can work out what happened.
0:16:45 > 0:16:51Sunderland flying boats were RAF reconnaissance aircraft that protected Allied convoys at sea.
0:16:53 > 0:16:57By 1944, they had powerful engines, machine guns, and even radar,
0:16:57 > 0:17:01making it even more surprising that the plane crashed here.
0:17:04 > 0:17:08It was an absolutely miserable night, even though it was June.
0:17:08 > 0:17:12They couldn't see, the visibility was 300-500 yards, apparently,
0:17:12 > 0:17:14and they were flying their last training mission.
0:17:14 > 0:17:18It's actually tragic, in a way. It was ten guys. Seven New Zealanders,
0:17:18 > 0:17:20three Brits and an Aussie,
0:17:20 > 0:17:24and a very experienced pilot, very experienced co-pilot.
0:17:24 > 0:17:27The pilot actually had about 800 hours of flying - very experienced.
0:17:27 > 0:17:31He'd actually flown this precise circuit before, at night.
0:17:31 > 0:17:34They were on their last training run and knew these parts,
0:17:34 > 0:17:37and they were to be posted to North Africa to protect convoys,
0:17:37 > 0:17:40which actually by 1944 was quite a cushy job, so they're safe,
0:17:40 > 0:17:44so it's very tragic that they came up here and crashed.
0:17:45 > 0:17:48Oh, yeah, you can start to see pieces here now.
0:17:48 > 0:17:50Up close, suddenly it's all becoming a lot clearer.
0:17:50 > 0:17:53There's two, three, four pieces there...
0:17:55 > 0:17:57Oh, look at this. Wow!
0:17:57 > 0:17:59God!
0:18:01 > 0:18:04This is incredible! Oh, my God!
0:18:05 > 0:18:08- RUSH OF WATER - It's absolutely gigantic!
0:18:10 > 0:18:12Wow!
0:18:16 > 0:18:19At the risk of sounding like a total idiot,
0:18:19 > 0:18:23I think this might be some kind of turret here,
0:18:23 > 0:18:26because it definitely seems to be on a swivel.
0:18:26 > 0:18:28And in fact, yeah, this...
0:18:28 > 0:18:31Yes, in fact it is, because I'll tell you what,
0:18:31 > 0:18:33these are the brackets for the 303s,
0:18:33 > 0:18:36the machine guns that would be the defensive armament.
0:18:36 > 0:18:41This is incredible here. This would probably be the turret on top of...
0:18:41 > 0:18:44In fact, I have a plan here, let me get it out.
0:18:44 > 0:18:47..the turret on top of the fuselage with these 303s mounted,
0:18:47 > 0:18:52obviously to protect the flying boat from enemy fighters.
0:18:52 > 0:18:57Here you have the machine guns up here, in the front here, and aft,
0:18:57 > 0:18:59these aft 303 machine guns.
0:18:59 > 0:19:02And those are quite clearly the machine-gun mounts
0:19:02 > 0:19:07so I never expected to be able to identify a piece of aircraft, and the first bit we've come across.
0:19:07 > 0:19:09It's absolutely fantastic.
0:19:11 > 0:19:14I think this is Tail End Charlie's seat.
0:19:14 > 0:19:16Incredible. Let's keep going,
0:19:16 > 0:19:18see if the beginner's luck keeps holding up.
0:19:23 > 0:19:28Some pieces here, looks like fuselage, I'd say,
0:19:28 > 0:19:33just twisted and obviously blown in here and then just got wedged under this rock.
0:19:33 > 0:19:40Imagine a piece of metal this big cartwheeling across the hillside,
0:19:40 > 0:19:42it's absolutely incredible.
0:19:42 > 0:19:46What's this here? Looks to me like it's just some pieces of fuselage.
0:19:49 > 0:19:50Wow!
0:19:50 > 0:19:55One of the propellers. There were four engines on this Sunderland,
0:19:55 > 0:19:58and this is obviously one of the props, and this is fascinating,
0:19:58 > 0:20:02look, you can see it's been buried, or it's buried itself, conceivably,
0:20:02 > 0:20:03and now slowly it's just...
0:20:03 > 0:20:09The ground is being eroded away to reveal this incredible find.
0:20:12 > 0:20:15All slightly bent, presumably as they hit the ground.
0:20:18 > 0:20:22'Climbing to the top of the glen, I think I'm closing in on the main wreckage site.
0:20:22 > 0:20:26'But does where the plane crashed give us a clue as to what happened?'
0:20:26 > 0:20:28It's very hard to see why the pilot would make a mistake,
0:20:28 > 0:20:31perhaps underestimating the height of St Kilda.
0:20:31 > 0:20:33Clearly the weather was bad
0:20:33 > 0:20:37but there must have been an element of equipment failure, instrument failure.
0:20:37 > 0:20:43Right, this is the top of the ridge here, pretty windy, and you can see
0:20:43 > 0:20:46what they were aiming for - just this lowest point of the saddle.
0:20:46 > 0:20:50But I'm pretty sure this is the main crash site, and they didn't make it.
0:20:50 > 0:20:55They were close, though. It's really tragic when you come up here and look at it.
0:20:55 > 0:20:58There's a lot of wreckage here, including some pretty big parts.
0:20:58 > 0:21:01This looks very clearly like the place when it went in.
0:21:01 > 0:21:03Gosh.
0:21:05 > 0:21:06Well...
0:21:09 > 0:21:11A piece of engine.
0:21:14 > 0:21:20Goodness me. You can see there's a sort of crater here, it's just hit straight in like that.
0:21:22 > 0:21:24Wow!
0:21:24 > 0:21:29And now that I'm standing here, it's just a matter of metres.
0:21:29 > 0:21:34It must have flown straight up this valley, been surprised by it, pulled as much power,
0:21:34 > 0:21:40given it as much stick, as they could, and they just couldn't edge over the ridge line there.
0:21:40 > 0:21:45It must have been 15-20 seconds of...unbearable terror.
0:21:45 > 0:21:48And then they went straight into the hillside.
0:21:49 > 0:21:52'It was night-time, and the weather was atrocious.
0:21:52 > 0:21:58'Even so, I think that equipment failure must have played a part in this tragic crash.
0:21:58 > 0:22:04'Otherwise, it's hard to see how an experienced pilot could make a mistake like this one.
0:22:04 > 0:22:11'Because of the terrible weather, it took over two weeks for a rescue party to reach St Kilda.
0:22:11 > 0:22:16'One account describes finding the body of a crewman who had survived the crash and taken shelter,
0:22:16 > 0:22:18'but the rescuers came too late.
0:22:21 > 0:22:28'In the end, all the men of Flight ML858 were given a burial at sea,
0:22:28 > 0:22:30'just four miles from this hillside.'
0:22:35 > 0:22:39St Kilda's connection with the military became formal a few years later.
0:22:42 > 0:22:48In 1957, the Ministry of Defence set up a radar tracking post here.
0:22:50 > 0:22:53There's been an MoD base here ever since.
0:22:53 > 0:22:57But how well do the military and the wildlife coexist?
0:22:59 > 0:23:05I've been called to the base for an emergency, which may tell us more.
0:23:05 > 0:23:08- Whereabouts is it? - It's just behind the steps...
0:23:08 > 0:23:09'A rescue mission is under way
0:23:10 > 0:23:15'and I join National Trust wildlife warden Sarah Money to lend a hand.'
0:23:16 > 0:23:18Oh, yes.
0:23:18 > 0:23:20- Oh! Head tucked under its wing. - I know.
0:23:21 > 0:23:24'In late summer, young birds on their first flight
0:23:24 > 0:23:29'are attracted by lights from the base and crash into the buildings.'
0:23:29 > 0:23:32No, don't go for me. Look, I'm rescuing you, just be grateful.
0:23:32 > 0:23:34SHRILL SQUAWKING
0:23:34 > 0:23:37All right, all right, all right, all right.
0:23:37 > 0:23:39- That's what they sound like normally. - I've got you.
0:23:39 > 0:23:42I've got you... I know, I know.
0:23:42 > 0:23:46'This disoriented chick is a Manx shearwater.'
0:23:46 > 0:23:52How handsome are you?! You're not grateful at all, are you? Come on, in the bag with you!
0:23:52 > 0:23:54No, no, no don't savage it.
0:23:54 > 0:23:56- I know. - SQUAWKING CONTINUES
0:23:56 > 0:23:57Put it down!
0:23:57 > 0:24:02'The chick doesn't seem to realise we're doing it a favour.'
0:24:02 > 0:24:04SQUAWKS OF PROTEST
0:24:04 > 0:24:07- Well, he's rescued, hurray!- He is.
0:24:07 > 0:24:10'The bird is fine - just a bit cross.'
0:24:14 > 0:24:18It's time for this feisty little Manx shearwater
0:24:18 > 0:24:22to be released, Sarah, so what's the best way to do this?
0:24:22 > 0:24:25Right, if you get him out the bag the same way you picked him up...
0:24:25 > 0:24:28- Yeah.- ..with the hands around its wings to control them...
0:24:28 > 0:24:31Shall I hold the bag...? There we go.
0:24:31 > 0:24:35- OK.- Then, I'd just point him out towards the sea...- OK.
0:24:35 > 0:24:37And just let him have a view of what he's gonna do.
0:24:39 > 0:24:42- So shall I go right down to the edge there?- Yeah, if you do...
0:24:42 > 0:24:45You're desperate to go, aren't you?
0:24:45 > 0:24:47So, no nasty-looking skuas around?
0:24:47 > 0:24:49- No, hopefully not.- Just fulmars.
0:24:49 > 0:24:53- And then you're gonna just wait for a little gust of wind.- Yeah.
0:24:53 > 0:24:55Just launch him, and he should fly straight out.
0:24:55 > 0:24:57- That's a good gust, yes? Ready? - Go for it!
0:24:57 > 0:25:00One, two, three, go! Woo-hoo!
0:25:01 > 0:25:03Don't fall in!
0:25:04 > 0:25:07- Ohh!- Doing well.- That's fantastic.
0:25:07 > 0:25:09Well, thanks, that was a huge honour.
0:25:09 > 0:25:13'The shearwater's not alone in needing to be rescued.
0:25:13 > 0:25:17'Every summer, many young birds make the same mistake.
0:25:17 > 0:25:21'But, as in this case, there's generally a happy ending.'
0:25:28 > 0:25:30The handful of men at the MoD base
0:25:30 > 0:25:33are now the only people who live here all year round.
0:25:33 > 0:25:37But they are surrounded by the relics of centuries of human life.
0:25:37 > 0:25:40The houses of the last St Kildans still stand in the village,
0:25:40 > 0:25:45and there are over 1,000 of these unique stone storage chambers,
0:25:45 > 0:25:48known as cleits, scattered across the hillsides.
0:25:50 > 0:25:53There are also some even more extraordinary hidden structures,
0:25:53 > 0:25:57and I'm going to go and look for them, with Steve's help.
0:25:57 > 0:26:03As a tiny isolated community, St Kilda was always vulnerable to attack from the sea.
0:26:03 > 0:26:10Vikings, pirates, and even a German U-boat in 1918, all came here on the offensive.
0:26:10 > 0:26:13But the St Kildans had their own method of defence.
0:26:13 > 0:26:18Must have been absolutely terrifying seeing a strange ship pull into that bay.
0:26:18 > 0:26:22I'd have thought any kind of contact for these people would be bad enough,
0:26:22 > 0:26:27but if it was the Vikings or someone that could do you serious damage, that would just be horrific!
0:26:27 > 0:26:30I think they had to assume that any ship they saw was hostile,
0:26:30 > 0:26:35because they couldn't risk all being caught here in the village and slaughtered,
0:26:35 > 0:26:38all the women being carted off, or all their stuff being taken.
0:26:38 > 0:26:43So what would a society like this, with no real fighting force,
0:26:43 > 0:26:45do against someone like the Vikings?
0:26:45 > 0:26:49No chance. The Vikings were some of the most incredible warriors ever,
0:26:49 > 0:26:52so you can either fight them or you can run. Fight or flight.
0:26:52 > 0:26:56They wouldn't fight the Vikings, they're too few, they're not trained warriors.
0:26:56 > 0:27:00So we reckon basically they charged into these hills and found hiding places.
0:27:00 > 0:27:03And there's basically some dugouts, almost, in that scree,
0:27:03 > 0:27:05so I'll go up and have a nose about.
0:27:05 > 0:27:10I can't believe for a second that there's anything up there to hide a 6'6" bloke wearing bright blue.
0:27:10 > 0:27:12Bright blue... You'd be surprised!
0:27:15 > 0:27:17Here's the scree slope.
0:27:17 > 0:27:19Uh... Nice and wet.
0:27:19 > 0:27:22'I'm looking for shelters that are unique to St Kilda,
0:27:22 > 0:27:27'secret hiding places built into the hillside, that are very difficult to spot.'
0:27:27 > 0:27:29So that's not what we're looking for.
0:27:29 > 0:27:33It can be very hard to tell in these scree slopes what's man-made and what's not.
0:27:33 > 0:27:37This one here is certainly man-made. I think this is more of a cleit.
0:27:37 > 0:27:40Looking at it, you can tell, the regular stones piled up.
0:27:40 > 0:27:44Clearly man-made, filled up with a bit of rubble, this could've been an original,
0:27:44 > 0:27:47but it feels more like a cleit, this round shape.
0:27:47 > 0:27:50Let's see if we can find one that's definitely a hidey-hole.
0:27:50 > 0:27:56Whilst I continue my search, Steve's keeping an eye on the slope to see if I can really disappear.
0:27:56 > 0:27:58STONES RATTLE
0:27:58 > 0:28:02- RUSHING WATER - No. Still see him... It's never gonna work.
0:28:03 > 0:28:06Right, what have we got here?
0:28:09 > 0:28:13Ah, right, now this feels definitely very different to a cleit.
0:28:13 > 0:28:16The ones I've seen here have all been raised above the ground,
0:28:16 > 0:28:21they've all been circular, keep the air flowing, keep the stuff in them dry for the storage.
0:28:21 > 0:28:23This is a trench, it's dug in, it's damp down here,
0:28:23 > 0:28:28and one thing it does do is keep you very, very out of vision
0:28:28 > 0:28:31to anyone down on that beach, like Steve.
0:28:33 > 0:28:35All right, Steve, can you see me now?
0:28:37 > 0:28:41Unbelievably, Dan, no, I can't. Where have you gone?
0:28:41 > 0:28:44I can see you, buddy, so don't come marauding in my village.
0:28:44 > 0:28:48How big is the hidey-hole you're in at the moment?
0:28:48 > 0:28:51You could fit a decent-sized family in here, I think,
0:28:51 > 0:28:53five, six, seven people in this one.
0:28:53 > 0:28:57It wouldn't be comfortable for long, but you could get them all in.
0:28:57 > 0:28:59And what's the view like up there?
0:28:59 > 0:29:02Would you be able to see people coming in, is it a good place to spy from?
0:29:02 > 0:29:08'Yeah, you can see the whole bay, the beach, the whole village,
0:29:08 > 0:29:12'and you can see a good 20-25 miles out to sea, to be honest.
0:29:12 > 0:29:15'So it's a fantastic place, actually...'
0:29:17 > 0:29:21Since I've been up here, a boat has actually sailed into the harbour,
0:29:21 > 0:29:23and it's quite poignant seeing that sail a long way away
0:29:23 > 0:29:25and it's getting closer and closer
0:29:25 > 0:29:27while I look for these hidey-holes.
0:29:27 > 0:29:30It just reminds you what was at stake for those guys.
0:29:30 > 0:29:34Any sail represented serious danger.
0:29:36 > 0:29:38STONES RATTLE
0:29:44 > 0:29:46While people have come and gone over the years,
0:29:46 > 0:29:51the animal life here has remained remarkably distinct from mainland Britain.
0:29:51 > 0:29:54There are no dogs or cats or rats here,
0:29:54 > 0:29:56no frogs, no foxes and no rabbits.
0:29:58 > 0:30:00There are sheep, though.
0:30:00 > 0:30:05Blackfaces descended from the ones the St Kildans left behind when they evacuated,
0:30:05 > 0:30:10and wild flocks of brown Soay sheep, which are a native breed.
0:30:12 > 0:30:17There's also one small native animal here that's a bit special.
0:30:17 > 0:30:22And this is the only place in the entire world that you can find it.
0:30:22 > 0:30:27Isolated island chains like St Kilda are fantastic places
0:30:27 > 0:30:29for studying evolution in action.
0:30:29 > 0:30:33The Galapagos and Charles Darwin would be a perfect example.
0:30:33 > 0:30:36The thing is, animals get stuck here and trapped from the mainland
0:30:36 > 0:30:41and develop very differently from their cousins way back over there.
0:30:41 > 0:30:44And here on St Kilda, it's not happened a tremendous amount,
0:30:44 > 0:30:48because most of the animals that are exciting that live here are birds.
0:30:48 > 0:30:51There is, however, one exception.
0:30:51 > 0:30:53Erm, it's a mouse.
0:30:53 > 0:30:57But what makes the St Kildan field mouse different from a mainland field mouse?
0:30:57 > 0:31:01In order to find out, I'm going to set up some friendly traps.
0:31:03 > 0:31:04Bit of apple here.
0:31:07 > 0:31:11Also some peanut butter. I'll slap that on there,
0:31:11 > 0:31:13put it into the trap,
0:31:13 > 0:31:17and place some cloth inside to function almost like bedding, keep the mouse warm,
0:31:17 > 0:31:24place the trap in there... and load it. Right, it's good to go.
0:31:27 > 0:31:30Some hours later,
0:31:30 > 0:31:33and I've called on the help of wildlife warden Sarah Money
0:31:33 > 0:31:35to help unload the traps.
0:31:35 > 0:31:39First signs are, there are plenty of mice.
0:31:39 > 0:31:43Six traps, all six of them sprung, although this one here, Sarah,
0:31:43 > 0:31:45appears to have had a kind of mighty mouse inside it.
0:31:45 > 0:31:50- Yep, a supermouse in there that's managed to wrangle his way out quite well.- Yes.
0:31:50 > 0:31:53- Shall we see what's happened inside the others?- Yep.
0:31:53 > 0:31:56Really, we're thinking these must just be St Kildan field mice.
0:31:56 > 0:32:01That's the only small animal we've got here, so hopefully they are.
0:32:01 > 0:32:04- OK. Let's see what we've got in this one here...- OK...
0:32:04 > 0:32:06RATTLING
0:32:09 > 0:32:15- SHE LAUGHS - Sadly, mighty mouse has struck again, and this trap's empty too!
0:32:17 > 0:32:18And this one.
0:32:24 > 0:32:28- And, believe it or not, this one too! - HE LAUGHS
0:32:28 > 0:32:32These mice must have evolved into some kind of rodent Houdinis!
0:32:32 > 0:32:34BOTH LAUGH
0:32:38 > 0:32:40OK, this one feels quite good.
0:32:40 > 0:32:42This one feels quite heavy.
0:32:45 > 0:32:47RATTLING
0:32:48 > 0:32:52Oh, he's trying to get out the other way!
0:32:52 > 0:32:53OK, there we go.
0:32:53 > 0:32:58So there we have our first St Kildan field mouse.
0:32:58 > 0:33:00He's very, very, beautiful, isn't he?
0:33:00 > 0:33:04They are, they've got much longer, fluffier fur than the mainland ones,
0:33:04 > 0:33:06- and quite a long tail as well.- Yeah.
0:33:06 > 0:33:09OK. Right, well, shall we weigh this one
0:33:09 > 0:33:12- and have a little look at how it's doing?- Yes.
0:33:13 > 0:33:19So that's about 80g, so it's only about 30g, which means it's either a youngish female
0:33:19 > 0:33:24or it's a young from this year - the young start appearing in traps in late June.
0:33:24 > 0:33:26That would still be big for a mainland field mouse.
0:33:26 > 0:33:29Yep, for a mainland field mouse that would be a big mouse.
0:33:29 > 0:33:35Maximum is about 29g, but St Kilda field mice get up to about 55g, so it's a small one.
0:33:35 > 0:33:38There you go... He's a little bit stressed
0:33:38 > 0:33:41so I think we should release him into one of the walls.
0:33:41 > 0:33:45- Yeah, release him into the stones? - Let's try this wall up here.
0:33:48 > 0:33:52The second I put this down, he'll disappear at a phenomenal rate...
0:33:54 > 0:33:56- BOTH: Whey!- Off he goes!
0:33:56 > 0:33:59- Great stuff. Very beautiful little creatures.- Wonderful.
0:33:59 > 0:34:02They're nice to live with, I've got a few at home.
0:34:02 > 0:34:05Its isolation means that the St Kildan field mouse
0:34:05 > 0:34:08has taken a different evolutionary route to the mainland field mouse.
0:34:08 > 0:34:11At nearly twice the size of its mainland cousin,
0:34:11 > 0:34:16the St Kildan field mouse really is a mighty mouse.
0:34:20 > 0:34:22There are few places in the world
0:34:22 > 0:34:27where history is written so vividly on the landscape as St Kilda.
0:34:27 > 0:34:29We already know that people lived here
0:34:29 > 0:34:31as far back as 1,200 years ago.
0:34:31 > 0:34:34But did people live here even earlier than that?
0:34:35 > 0:34:40One particular remain here that I want to check out, it's called the House of the Fairies,
0:34:40 > 0:34:45which shows that the people living here on St Kilda knew that it was old, almost mythically old.
0:34:45 > 0:34:50One small problem is that all these cleits and all these houses look exactly the same.
0:34:52 > 0:34:57'Luckily for me, some conscientious archaeologist has drawn up a plan, with each house and cleit numbered.'
0:34:59 > 0:35:02Every single stone building marked out, it's fantastic.
0:35:02 > 0:35:04Should be no trouble finding this site at all.
0:35:04 > 0:35:06Unfortunately, it is through the marsh.
0:35:06 > 0:35:08Ugh!
0:35:14 > 0:35:18Probably should have gone the easy way. That's 84...
0:35:18 > 0:35:21that's 83...
0:35:21 > 0:35:2482, 81...
0:35:24 > 0:35:29This one shouldn't be here... ..75...
0:35:29 > 0:35:31Ah-ha! Here it is.
0:35:31 > 0:35:36Wow, yeah, now this is a completely different type of remain here.
0:35:36 > 0:35:39Oh, yeah, this is great.
0:35:40 > 0:35:43It's underground, it's damp in there, it's full of puddles,
0:35:43 > 0:35:47not a house, definitely not for storage, let's go in.
0:35:47 > 0:35:49'But what is this structure?'
0:35:49 > 0:35:53Ha-ha! It's pretty dank in here.
0:35:53 > 0:35:55Yeah.
0:35:55 > 0:35:59There's a little side passage round here.
0:35:59 > 0:36:00Torch...
0:36:02 > 0:36:06OK, it's pretty small in there, it's not clear what it does,
0:36:06 > 0:36:10perhaps there's been a collapse. I'll see if I can get in there,
0:36:10 > 0:36:12have a little look at things.
0:36:12 > 0:36:14HE GASPS
0:36:20 > 0:36:26There's wonderful big slabs of rock here and they make up the roof.
0:36:26 > 0:36:30Now there's possibly been a collapse at the end,
0:36:30 > 0:36:34but you can clearly see these enormous lintels, this sort of roofing here.
0:36:34 > 0:36:37Huge effort, to create something like this.
0:36:37 > 0:36:39Right...
0:36:39 > 0:36:43'I'm beginning to think that this is a burial chamber.
0:36:43 > 0:36:45'But how old is it?'
0:36:45 > 0:36:49Goes in about another five metres, I suppose,
0:36:49 > 0:36:51and then it stops, it looks like another collapse here.
0:36:51 > 0:36:55Of course, this tunnel might go a lot further in, that's very exciting.
0:36:55 > 0:36:58But look at these stones here!
0:36:58 > 0:37:03These are actually the biggest building stones that I've seen used anywhere in the village.
0:37:03 > 0:37:05Some of these are gigantic,
0:37:05 > 0:37:10so whoever built this was...had the ability to move these.
0:37:11 > 0:37:17I've been in chambers like this in Ireland, in southern England, and it's amazing to think that here,
0:37:17 > 0:37:20right out at the north-west extremity of the British Isles,
0:37:20 > 0:37:23there's still that same culture of digging tunnels
0:37:23 > 0:37:27and using rocks like this to create, perhaps, burial chambers and stuff.
0:37:27 > 0:37:34It does seem to prove that there have been people here on St Kilda for at least 2,000 years.
0:37:34 > 0:37:39'It is astonishing that somewhere as remote and harsh as St Kilda
0:37:39 > 0:37:42'could have been home to humans for so long.
0:37:42 > 0:37:46'But could people have been living here even earlier than that?'
0:37:46 > 0:37:50These places just aren't really built for people my size.
0:38:02 > 0:38:04We're now halfway through our time here,
0:38:04 > 0:38:09and I'm more intrigued by this wild place than ever.
0:38:09 > 0:38:13It is extraordinary, and it's still just as extraordinary now, a few days in,
0:38:13 > 0:38:17that I'm actually still in the British Isles.
0:38:21 > 0:38:26It's a very, very strange place, and the weather can change in a heartbeat.
0:38:26 > 0:38:30So one moment it can look very benign and blue and sparkly,
0:38:30 > 0:38:34and the next minute it can be like this, where the weather's completely closed in
0:38:34 > 0:38:37and you can barely see your hand in front of your face.
0:38:37 > 0:38:38You never know what to expect.
0:38:42 > 0:38:49It still feels like it's got this sort of strange, primeval pulse.
0:38:49 > 0:38:52It still feels very alive and kind of mysterious,
0:38:52 > 0:38:56and I think you could be here for months and months and months
0:38:56 > 0:38:58and never quite get to grips with it.
0:39:00 > 0:39:04As a historian, it's been fascinating because
0:39:04 > 0:39:07there's so many levels of history here in this confined space.
0:39:07 > 0:39:12It's isolated, so we can identify different periods of its history, all these layers.
0:39:12 > 0:39:16The difficult thing, though, has been, because only one tiny part of these islands
0:39:16 > 0:39:18is suitable for habitation,
0:39:18 > 0:39:22all the history is piled on top of each other within a couple of acres
0:39:22 > 0:39:26just down there in the village. So that's been really exciting.
0:39:31 > 0:39:36I've wanted to come to St Kilda for a very long time, since I was in my teens,
0:39:36 > 0:39:38and it had an awful lot to live up to.
0:39:38 > 0:39:44You only get a taste of the real extremes of a place from what you hear before you get there.
0:39:44 > 0:39:49But it's really lived up to my greatest hopes, I think.
0:39:51 > 0:39:55Even beachcombing here is an adventure.
0:39:55 > 0:39:59You can find things on St Kilda that you'd be astonished to come across on the mainland.
0:39:59 > 0:40:03I was hoping to catch a glimpse of a passing whale,
0:40:03 > 0:40:07but instead I've come across a poignant reminder of their presence.
0:40:09 > 0:40:12Well, I smelt this long before I saw it.
0:40:12 > 0:40:17It's rather a macabre reminder of the amazing things that live in the waters around St Kilda.
0:40:17 > 0:40:21You can see instantly it's a whale of some kind.
0:40:21 > 0:40:26This has vertebrae, backbone and ribs, just like we do.
0:40:26 > 0:40:29And looking at the jaw bone here,
0:40:29 > 0:40:33you can see the sockets that once held its teeth,
0:40:33 > 0:40:36so it's not a baleen whale, it's not a minke whale.
0:40:36 > 0:40:38From the length of it, the tail over there,
0:40:38 > 0:40:41probably about 12, 13 feet long, a good-sized animal.
0:40:43 > 0:40:46I reckon that this was once a pilot whale.
0:40:47 > 0:40:50Unfortunately now, though, just food for the gulls.
0:40:55 > 0:40:57SEA BIRDS CRY
0:40:58 > 0:41:03St Kilda is world-famous for its extraordinary bird life,
0:41:03 > 0:41:06the puffins, gannets and fulmars
0:41:06 > 0:41:08who've nested here for thousands of years.
0:41:08 > 0:41:13But there's a newcomer who's making its presence felt.
0:41:13 > 0:41:18Down here is possibly one of the most dangerous parts of the island.
0:41:21 > 0:41:26This ridge overlooking the whole of St Kilda is home to the great skuas.
0:41:26 > 0:41:31It's been nicknamed Bomb Alley because of the birds' terrifying behaviour.
0:41:34 > 0:41:38Great skuas have a reputation for terrorising other sea birds,
0:41:38 > 0:41:40forcing them to drop their catch.
0:41:42 > 0:41:45And those are the lucky ones. The others, they kill.
0:41:45 > 0:41:49This...um...rather fetching garment is a tea cosy,
0:41:49 > 0:41:53and I'm assured by the people at the National Trust who work here
0:41:53 > 0:42:00that this is the best defence against one of the biggest, nastiest birds in Britain.
0:42:00 > 0:42:02I'm ready!
0:42:04 > 0:42:06BIRD SQUAWKS
0:42:08 > 0:42:10Whoo! Ha-ha-ha!
0:42:12 > 0:42:14Oh, here comes another one...
0:42:15 > 0:42:16Ah!
0:42:18 > 0:42:20Ooh... Ha-ha-ha!
0:42:23 > 0:42:27Skuas came to St Kilda only 30 years ago, from the Western Isles.
0:42:27 > 0:42:31As you can see, they're not at all keen on human company.
0:42:32 > 0:42:35But are skuas just thugs like East End bouncers?
0:42:35 > 0:42:37Well, of course they're not.
0:42:37 > 0:42:39I'm going to take this off out of respect,
0:42:39 > 0:42:46because they are ground-nesting birds... I've got a chick right here.
0:42:46 > 0:42:50..and like any good parent, they're protective of their young,
0:42:50 > 0:42:53so that's why they will dive-bomb anything coming into their territory.
0:42:53 > 0:42:57Traditionally, great skuas live off fish,
0:42:57 > 0:43:00but as fish stocks reduce they must look elsewhere for their dinner,
0:43:00 > 0:43:04even if it means a spot of cannibalism.
0:43:04 > 0:43:07This is what can happen to a skua chick
0:43:07 > 0:43:12if both parents are forced to leave it and go and look for food.
0:43:12 > 0:43:14Skuas are incredibly opportunistic,
0:43:14 > 0:43:19and if they see easy pickings like their neighbour's chicks, they go for it.
0:43:19 > 0:43:24It seems extraordinary that they would even eat their own species,
0:43:24 > 0:43:29but all the great skuas are doing is ensuring their own survival.
0:43:29 > 0:43:33There are now 200 breeding pairs of skuas on St Kilda,
0:43:33 > 0:43:38but they may be thriving at the expense of others.
0:43:44 > 0:43:47I'm on the search for a much rarer bird than the skua -
0:43:47 > 0:43:52the Leach's storm-petrel, Britain's most secretive bird.
0:43:54 > 0:43:59St Kilda is home to an important colony of them, and I want to find out how they're doing.
0:43:59 > 0:44:04I'm joined by Sarah Money, the National Trust warden.
0:44:04 > 0:44:11These birds are tiny. They spend all day out at sea, and they nest at night in deep burrows.
0:44:11 > 0:44:13No wonder I've never seen one.
0:44:13 > 0:44:15BIRD CALLS
0:44:15 > 0:44:17Sarah has a trick up her sleeve, though.
0:44:17 > 0:44:19BIRD CALLS AGAIN
0:44:19 > 0:44:22So, Sarah, can you explain to me what you're playing out of that?
0:44:22 > 0:44:27It's a Leach's petrel male chatter call. So it's a Leach's petrel from St Kilda.
0:44:27 > 0:44:32It's a male. We're playing it to get males who are nesting in burrows amongst the rocks to respond.
0:44:32 > 0:44:34BIRD CALL PLAYS AGAIN
0:44:35 > 0:44:38- Do you know what, I can...I can hear something over there.- Yep.
0:44:38 > 0:44:40If we head over there...
0:44:40 > 0:44:42BIRD CALL PLAYS AGAIN
0:44:42 > 0:44:45So why would the males be responding to this call here?
0:44:45 > 0:44:47They think it's an invading male,
0:44:47 > 0:44:51so they're saying, "Right, this is my burrow, leave me alone!"
0:44:54 > 0:44:55BIRD CALL PLAYS AGAIN
0:44:55 > 0:44:59And at the moment, the males are inside the burrows, sitting on eggs?
0:44:59 > 0:45:03Yes, some of them might be on chicks, but most of them are just sitting on eggs.
0:45:06 > 0:45:08- There's definitely one just over here.- I know.
0:45:19 > 0:45:21BIRD CALLS
0:45:21 > 0:45:24- Oop. Heard one behind there! - That's wonderful!
0:45:24 > 0:45:29- ANOTHER BIRD CALLS And here... - What an unbelievable noise!
0:45:29 > 0:45:32So they're talking to this, and he's talking to that one over there.
0:45:32 > 0:45:34CALL PLAYS
0:45:34 > 0:45:37BIRD RESPONDS
0:45:37 > 0:45:39- There we go.- Wonderful!
0:45:39 > 0:45:43- He's right down at the base... - He's very, close, isn't he?- Yeah.
0:45:43 > 0:45:49Now we've found a nest, Sarah has some more specialised equipment to study the birds in detail.
0:45:49 > 0:45:54- Endoscope?- It is, yeah, I hide it in this cleit, just stored in a survival bag and left up here.
0:45:54 > 0:45:57- Cos it's so big, we don't want to carry it up every time.- Right.
0:45:58 > 0:46:00'More commonly found in hospitals,
0:46:00 > 0:46:04'this endoscopic camera will help us confirm that there's a bird in the burrow,
0:46:04 > 0:46:07'and let us take a closer look at the bird itself.'
0:46:09 > 0:46:13So what are you actually hoping to achieve by looking inside these burrows?
0:46:13 > 0:46:17We're trying to find out things like egg-laying date and hatching date,
0:46:17 > 0:46:20how long it takes the youngs to fledge, the growth rate,
0:46:20 > 0:46:23how often the adults go in to be with the youngsters as well.
0:46:23 > 0:46:27Just as much information as we can get. Because it's a tiny bird, comes in at night,
0:46:27 > 0:46:29lives in a deep burrow, not much is known about them,
0:46:29 > 0:46:31so any information is wonderful.
0:46:35 > 0:46:38Now, you've marked it here. Where does the burrow actually go?
0:46:38 > 0:46:40I can't see an entrance, nothing!
0:46:40 > 0:46:44The burrow entrance is just down here, and it's not very obvious,
0:46:44 > 0:46:47but the burrow goes up there and they tend to nest under the rocks.
0:46:47 > 0:46:50So we just pop that in the burrow entrance
0:46:50 > 0:46:53- and you see this sort of grass... - Yeah.
0:46:53 > 0:46:56..and move it around a bit and...
0:46:56 > 0:46:59just check we're going in the right direction.
0:46:59 > 0:47:01I'm just wondering if that's an egg.
0:47:01 > 0:47:03- I can see something.- Or a bird, even.
0:47:03 > 0:47:05There's definitely something.
0:47:06 > 0:47:10- Is that nesting material? - It is, I think, yep, can you see?
0:47:10 > 0:47:12'It's a tantalising glimpse,
0:47:12 > 0:47:17'but this bird is too deep underground to take out and get a really good look at.
0:47:20 > 0:47:24'In order to see one, I'm gonna have to join the night shift.'
0:47:32 > 0:47:38'It's now 2am, and whilst the others are all tucked up in their tents, I've joined Will Miles,
0:47:38 > 0:47:43'who's been studying the Leach's storm-petrel almost every night for months.'
0:47:43 > 0:47:45BIRD CALLS
0:47:45 > 0:47:50'Now the birds are active, Will uses the recording to lure them into a fine mist net.'
0:47:50 > 0:47:53Just open the net and lift it out of the pocket like that...
0:47:53 > 0:47:55Oh, look at that, that's beautiful!
0:47:55 > 0:47:57Shall we go in and ring it?
0:47:57 > 0:47:58- Let's do that.- Yep.
0:47:58 > 0:48:00'At last, my first chance
0:48:00 > 0:48:05'to see St Kilda's very rare Leach's storm-petrel.'
0:48:05 > 0:48:08This is a very significant population of Leach's storm-petrels?
0:48:08 > 0:48:14Yeah, in British terms, it's thought that up to maybe 95%
0:48:14 > 0:48:19of the British and Irish Leach's petrel population is breeding here on St Kilda,
0:48:19 > 0:48:23so that is maybe a maximum of 45,000 pairs.
0:48:23 > 0:48:26'These birds spend almost all their lives out at sea.
0:48:26 > 0:48:29'They're only coming into land now because it's the breeding season.
0:48:29 > 0:48:33It's a real privilege to see one so close up.'
0:48:34 > 0:48:37164mm.
0:48:37 > 0:48:43'It's thought that their numbers are declining, and part of Will's study is to try and find out why.'
0:48:43 > 0:48:4782g, with the bag,
0:48:47 > 0:48:52and the ring number is 58474.
0:48:52 > 0:48:54No sooner is the information gathered
0:48:54 > 0:48:56than it's time to let the petrel go.
0:48:56 > 0:49:00- BIRD THUDS Into the ground.- And around a bit.
0:49:00 > 0:49:02And then straight up into the sky.
0:49:02 > 0:49:04- And off it goes!- Away out to sea.
0:49:05 > 0:49:10'Will has come up with a theory on why their numbers may be going down.
0:49:10 > 0:49:12'He believes the clue is in these pellets
0:49:13 > 0:49:16'regurgitated by the island's most aggressive inhabitant,
0:49:16 > 0:49:19'Kate's old friends, the great skuas.'
0:49:19 > 0:49:23I can't believe these have been regurgitated, that's incredible!
0:49:23 > 0:49:28There really is nothing that these birds won't eat, I mean they're eating razorbill heads whole.
0:49:28 > 0:49:32All the brains and eyes have been taken out, probably digested,
0:49:32 > 0:49:34and that just comes straight back up.
0:49:34 > 0:49:39And...well, you can tell what that one is - there's no guessing, that's definitely a puffin.
0:49:39 > 0:49:42- And this one here, is that guillemot?- Yep.
0:49:42 > 0:49:46That looks about the right kind of size for one of ours, isn't it?
0:49:46 > 0:49:49Yes, this very, very, tiny little skull
0:49:49 > 0:49:51with a very delicate little black beak.
0:49:51 > 0:49:53It's a Leach's petrel.
0:49:53 > 0:49:57'Although larger, more common birds have obviously also been eaten,
0:49:57 > 0:50:01'the great skua seems to find the Leach's storm-petrel a particular delicacy.'
0:50:01 > 0:50:05Two tiny little feet sticking out the bottom of a pellet,
0:50:05 > 0:50:07that really is rather macabre, isn't it?
0:50:07 > 0:50:09Any idea what that would be?
0:50:09 > 0:50:11These are, again, Leach's petrel feet.
0:50:11 > 0:50:16Right, OK, so there's really no doubt, then, that the skuas are definitely eating...
0:50:16 > 0:50:18Yeah, they really have a go at the petrels.
0:50:18 > 0:50:22'Even though the Leach's storm-petrel only returns from sea in the middle of the night,
0:50:22 > 0:50:28'it now seems likely the great skua hunts them at night as they try to enter their burrows.
0:50:28 > 0:50:33'Will reckons the skuas are making a real impact on the population of Leach's storm-petrels.
0:50:33 > 0:50:40'It may be that St Kilda's newest resident is now endangering the survival of one of its rarest.
0:50:40 > 0:50:45'Let's hope there are still storm-petrels on St Kilda in years to come.'
0:50:49 > 0:50:51In our time here so far,
0:50:51 > 0:50:56we've found out a lot about this unique wilderness.
0:50:56 > 0:51:00These little islands, far from the mainland,
0:51:00 > 0:51:04have been almost untouched by humans for 80 years.
0:51:06 > 0:51:09We've seen how the wildlife under water is thriving...
0:51:09 > 0:51:11I'm really pleased with that find...
0:51:11 > 0:51:16..and how St Kilda's very own species of mouse is doing well.
0:51:16 > 0:51:19He's very, very, beautiful, isn't he?
0:51:20 > 0:51:23St Kilda's isolation means that its history lies preserved,
0:51:23 > 0:51:26in ruins and fragments on the ground.
0:51:27 > 0:51:31We've traced back human life here till the Iron Age.
0:51:33 > 0:51:36And we've solved the mystery of a more recent tragedy.
0:51:36 > 0:51:41There must have been an element of equipment failure, instrument failure...
0:51:46 > 0:51:52Now it's time to put ourselves to the test - well, not me, actually, just the boys.
0:51:53 > 0:51:58The people who work here have found a novel way to keep themselves fit,
0:51:58 > 0:52:02and take on St Kilda's intimidating landscape.
0:52:02 > 0:52:06- So are you guys ready?- Not really, no!- No!- We spent our day absolutely terrified...
0:52:06 > 0:52:10'Timekeeping will be conducted by female record holder Sam Dennis.'
0:52:10 > 0:52:13- What are you making us do? - It's the chimney run.
0:52:13 > 0:52:16Modern tradition. Army guys used to do this all the time,
0:52:16 > 0:52:18and we've got to keep up that tradition.
0:52:18 > 0:52:22- Start here, head for the chimney... - Oh, my God!- ..to the top... - Oh, my G...!
0:52:22 > 0:52:27So I've come up here first, because obviously I didn't want the boys to be beaten by a girl,
0:52:27 > 0:52:29because it would just be too embarrassing for them.
0:52:29 > 0:52:34But Dan and Steve are going to do the proper race.
0:52:34 > 0:52:38They're gonna race round the bay here,
0:52:38 > 0:52:44which as you can see is a gentle slope upwards, just to get them in the mood,
0:52:44 > 0:52:49cross the helipad, and then up this ludicrous slope.
0:52:49 > 0:52:54- It's got to be about 280-300 metres to the top there, hasn't it?- Just about, yes.
0:52:54 > 0:52:57And you've done this in an insane time?
0:52:57 > 0:53:01Yeah. Yeah, I'd like to see if you guys could beat that time today?
0:53:01 > 0:53:04- What's your best time?- Er, about 13.5 minutes so far.
0:53:04 > 0:53:07You are the smuggest person I have ever met in my life.
0:53:07 > 0:53:11I swear to God, we're gonna take you round the back and beat you up!
0:53:12 > 0:53:16- Yeah.- Oh, God, shall we do this, Steve?
0:53:16 > 0:53:17I guess so, yeah.
0:53:18 > 0:53:23- Any tips?- Erm, just...- Tell me, not him!- Just don't stop.
0:53:23 > 0:53:26I think they're possibly under starter's orders.
0:53:26 > 0:53:28On your marks... Get set...
0:53:30 > 0:53:31Go!
0:53:32 > 0:53:38I can see...Dan loping across just in front of the helipad...
0:53:40 > 0:53:43Steve's taken an early lead,
0:53:43 > 0:53:47but not going too hard off the start might be Dan's big idea.
0:53:48 > 0:53:50It's all part of the plan,
0:53:50 > 0:53:51all part of the plan.
0:53:53 > 0:53:58Who's gonna win? Well, Dan's got unfeasibly long legs,
0:53:58 > 0:54:01but a long stride on that slope may not do him any good at all.
0:54:01 > 0:54:06Steve, wildly competitive, exercises like a fiend, but shorter.
0:54:06 > 0:54:08Who knows?
0:54:10 > 0:54:16The chimney run is 700 metres long, and the last 200 are almost vertical.
0:54:22 > 0:54:25Ohhh, but they're going to be in agony...
0:54:26 > 0:54:27..just about now...
0:54:35 > 0:54:37HE GASPS
0:54:37 > 0:54:42'It's so steep, resorting to all fours is the only way to get up here.'
0:54:48 > 0:54:50C'mon, Steve!
0:54:50 > 0:54:52SHE LAUGHS
0:54:52 > 0:54:53Wow!
0:54:55 > 0:54:57Where's Dan?
0:54:57 > 0:54:58You don't care, do you?
0:54:58 > 0:55:00SHE LAUGHS
0:55:05 > 0:55:06C'mon, mate...
0:55:06 > 0:55:08THEY GASP
0:55:13 > 0:55:15C'mon, mate, you're nearly there!
0:55:15 > 0:55:18HE GASPS HEAVILY
0:55:19 > 0:55:21THEY GASP
0:55:30 > 0:55:33Right, the official times on the watch...
0:55:34 > 0:55:36'12.50 for Steve,
0:55:36 > 0:55:41- 'and an impressive 13.12 for Dan.' - Ah, nice!
0:55:41 > 0:55:44- Thank you, Sam.- Well done to the both of them.
0:55:46 > 0:55:49That is thoroughly respectable,
0:55:49 > 0:55:52and I, for one...
0:55:53 > 0:55:56- I'm proud of you both.- Thank you!
0:55:57 > 0:56:01But I don't want to get much closer to you until you've had a shower.
0:56:01 > 0:56:03The feeling's mutual!
0:56:10 > 0:56:12Next time on Britain's Lost World,
0:56:12 > 0:56:16Steve takes on the ultimate St Kildan challenge...
0:56:21 > 0:56:25..Dan looks for human life beneath the waves...
0:56:25 > 0:56:29..and I finally learn where our St Kildan mail boat ended up.
0:56:29 > 0:56:31Ooh, it's ringing...
0:56:55 > 0:56:58Subtitles by Red Bee Media Ltd
0:56:58 > 0:57:01E-mail subtitling@bbc.co.uk