0:00:08 > 0:00:11In the far reaches of the Pacific Ocean...
0:00:14 > 0:00:18lies a land cut-off from the rest of the world...
0:00:20 > 0:00:23since the time of the dinosaurs.
0:00:30 > 0:00:35After 80 million years of isolation,
0:00:35 > 0:00:38nature has gone its own way.
0:00:41 > 0:00:46In this lost world, life plays by different rules.
0:00:50 > 0:00:51Penguins in the forests...
0:00:53 > 0:00:55parrots in the snow...
0:00:57 > 0:01:01and predators from prehistory.
0:01:04 > 0:01:09Their lives are dominated by the most powerful forces on earth.
0:01:11 > 0:01:15When humans finally arrived, they discovered
0:01:15 > 0:01:21nowhere is more strange and mysterious than New Zealand.
0:01:38 > 0:01:42At the extreme southern tip of New Zealand,
0:01:42 > 0:01:46the influence of the South Pole is surprisingly clear.
0:01:50 > 0:01:54The Aurora Astralis, the Southern Lights.
0:02:02 > 0:02:06At 47 degrees south, the next stop is Antarctica.
0:02:11 > 0:02:18At these latitudes in summer, the nights don't last long.
0:02:18 > 0:02:21So there is only a brief window of opportunity
0:02:21 > 0:02:24for the creatures who hunt by night.
0:02:32 > 0:02:36Like this mysterious beachcomber.
0:02:36 > 0:02:39He's only found in New Zealand
0:02:39 > 0:02:41and very rarely seen.
0:02:46 > 0:02:50He has stubby wings, but he's too heavy to fly.
0:02:55 > 0:02:59A wild southern brown kiwi.
0:03:08 > 0:03:13Just after sunset, the kiwi hits the beach in search of sand-hoppers.
0:03:22 > 0:03:27He relies on his sense of smell and sniffs out the bugs through
0:03:27 > 0:03:30nostrils at the end of his bill.
0:03:35 > 0:03:39Kiwis come out at night to avoid daytime predators.
0:03:39 > 0:03:42So it's rare to get such a good look at them.
0:03:54 > 0:03:59Cold nights and meagre pickings mean that as the first rays of the sun
0:03:59 > 0:04:03appear, this kiwi doesn't run and hide.
0:04:10 > 0:04:12He keeps hunting into dawn.
0:04:15 > 0:04:21The conditions here force the southern brown kiwi to stay out in daylight.
0:04:34 > 0:04:38To live this far south, it has had to completely alter its normal routine.
0:04:50 > 0:04:55Every creature who lives in this wild and remote part of the world
0:04:55 > 0:04:59must come up with radical solutions to the challenges of living here.
0:05:04 > 0:05:09New Zealand's closeness to the pole makes it vulnerable to storms,
0:05:09 > 0:05:14particularly in the south, where they say you can feel the icy breath
0:05:14 > 0:05:16of Antarctica.
0:05:31 > 0:05:37New Zealand's southern beaches are a refuge for one incredible
0:05:37 > 0:05:39subantarctic pioneer.
0:05:50 > 0:05:52A New Zealand sea lion.
0:05:54 > 0:05:58Possibly the rarest sea lion in the world.
0:06:00 > 0:06:04Almost hunted to extinction 150 years ago.
0:06:12 > 0:06:18But then, in 1993, one female returned and gave birth.
0:06:20 > 0:06:24Over 20 years on, their descendants are still here.
0:06:27 > 0:06:31An adult male can weigh about as much as four grown men.
0:06:34 > 0:06:37It can take eight years to reach maturity.
0:06:39 > 0:06:42SEA LION ROARS
0:06:45 > 0:06:50Adult male sea lions are the rugby front row of the South Island.
0:06:53 > 0:06:58During the breeding season, the beaches become their battleground.
0:07:00 > 0:07:05Only the biggest and toughest will win the right to breed.
0:07:12 > 0:07:17A female returning from a three-day fishing trip doesn't want to attract
0:07:17 > 0:07:18the males' attention.
0:07:29 > 0:07:32She has something else on her mind.
0:07:43 > 0:07:47She might be able to dive deeper than any other sea lion on earth,
0:07:47 > 0:07:53but hauling 160kg up over a sand dune is more of a struggle.
0:07:53 > 0:07:56SEA LION CALLS
0:08:20 > 0:08:24There is a reason for all this effort.
0:08:24 > 0:08:26She's searching for something precious.
0:08:38 > 0:08:41The centre of her world.
0:08:41 > 0:08:43Her pup.
0:08:45 > 0:08:47Only a couple of weeks old.
0:08:55 > 0:09:01By hiding her baby in the woods, she avoids the bullyboys on the beach.
0:09:07 > 0:09:12In the safety of the forest, he can suckle in peace.
0:09:16 > 0:09:18All along the southern coast,
0:09:18 > 0:09:22sea creatures come ashore to find shelter.
0:09:29 > 0:09:34But living on land when you're meant to be at sea can bring problems of
0:09:34 > 0:09:36its own.
0:09:45 > 0:09:47On the Snares Islands,
0:09:47 > 0:09:50penguins build their nests amongst the trees
0:09:50 > 0:09:53because it's a safe place to breed.
0:09:53 > 0:09:57But protection in these forests comes at a price.
0:09:57 > 0:09:59BIRDS SQUAWK
0:10:12 > 0:10:17Thousands of tiny feet turn the nesting ground into a quagmire.
0:10:24 > 0:10:28They get covered in sticky mud,
0:10:28 > 0:10:31not just their feet, but their precious feathers, too.
0:10:34 > 0:10:39The mud not only ruins their looks, it could threaten their lives.
0:10:42 > 0:10:46Their densely-packed plumage is their survival suit.
0:10:48 > 0:10:50If their feathers are dirty,
0:10:50 > 0:10:53they won't insulate as effectively
0:10:53 > 0:10:56and the penguins will lose vital energy.
0:11:01 > 0:11:04These are coastlines where risks cannot be taken.
0:11:07 > 0:11:10So before he dives headfirst into the sea,
0:11:10 > 0:11:13this penguin checks into the penguin spa.
0:11:15 > 0:11:20The rock pool gives him a chance to wash and scrub up in safety.
0:11:32 > 0:11:34He combs through his feathers...
0:11:37 > 0:11:39then waterproofs them with a wax from an oil gland
0:11:39 > 0:11:42at the base of his tail.
0:11:44 > 0:11:47Not only does this wax help him stay warm,
0:11:47 > 0:11:51it will also help glide through the water more efficiently.
0:11:55 > 0:12:00Insulated and waterproof once more, he's now dressed for dinner.
0:12:08 > 0:12:13Ready to tackle the wild ocean beyond.
0:12:33 > 0:12:36The waters surrounding the South Island
0:12:36 > 0:12:39are some of the most brutal on earth.
0:12:42 > 0:12:45These are the Roaring Forties.
0:12:46 > 0:12:49Gale force winds rage year-round,
0:12:49 > 0:12:52churning up seas that batter the shores.
0:12:57 > 0:13:00Fierce weather systems can arrive without warning.
0:13:04 > 0:13:07Open ocean swells and storms charge up
0:13:07 > 0:13:11from Antarctica and create massive waves up to eight metres high.
0:13:16 > 0:13:17It's always a challenge.
0:13:18 > 0:13:21The challenge of being able work the area.
0:13:21 > 0:13:23You just have to be prepared all the time.
0:13:25 > 0:13:30Tackling the tempest is a regular occurrence for Peter Young.
0:13:30 > 0:13:32It's his commute to work.
0:13:36 > 0:13:40But the view from his workplace makes up for it.
0:13:40 > 0:13:44One of the most spectacular sights in New Zealand -
0:13:44 > 0:13:45Fiordland.
0:13:58 > 0:14:03This labyrinth of steep-sided fjords and inlets offers shelter to a whole
0:14:03 > 0:14:04host of marine life.
0:14:15 > 0:14:21For bottlenosed dolphins, it's a place to rest and feed.
0:14:25 > 0:14:29And a nursery, where baby fur seals can build up their strength.
0:14:34 > 0:14:37Peter is a ranger for the Department of Conservation.
0:14:38 > 0:14:41He monitors and protects the wildlife here.
0:14:43 > 0:14:47The diversity of Fiordland is something I love.
0:14:47 > 0:14:49It's something that not a lot of people
0:14:49 > 0:14:52in the world will ever get to do.
0:14:52 > 0:14:55You sort of get a 40-tonne whale just come cruising up.
0:14:57 > 0:14:59Right beside the boat, rolling over,
0:14:59 > 0:15:02exposing their bellies to you as if they want a bit of a scratch.
0:15:10 > 0:15:14Fiordland is the jewel of the South Island.
0:15:17 > 0:15:23At almost 5,000 square miles, it's New Zealand's biggest national park.
0:15:39 > 0:15:43This dramatic landscape was gouged out by glaciers
0:15:43 > 0:15:45during the last ice age.
0:15:48 > 0:15:51Creating incredibly deep saltwater inlets.
0:15:55 > 0:15:58Here, two distinct worlds meet.
0:16:00 > 0:16:03Fresh water from the land
0:16:03 > 0:16:06mixes with saltwater from the ocean...
0:16:09 > 0:16:11to create a unique ecosystem.
0:16:22 > 0:16:25Fresh water arrives here from the forests,
0:16:25 > 0:16:29rich in tannins from rotting vegetation,
0:16:29 > 0:16:31turning it into a dark tea.
0:16:40 > 0:16:45It pours off these cliffs to mix with the saltwater below.
0:17:00 > 0:17:03Less dense than saltwater,
0:17:03 > 0:17:08the stained fresh water floats above and blocks out the light...
0:17:15 > 0:17:20creating a dark and cold underwater world.
0:17:23 > 0:17:28Here, creatures that normally live in the inky depths of the ocean make
0:17:28 > 0:17:30their home much nearer to the surface.
0:17:39 > 0:17:43Black corals normally grow below 100 metres, but here,
0:17:43 > 0:17:47underwater forests of them thrive in the shallows.
0:17:53 > 0:17:58It may be known as black coral, but it appears white as it's covered in
0:17:58 > 0:18:00millions of tiny coral polyps,
0:18:00 > 0:18:02all feeding in the current.
0:18:04 > 0:18:08Black corals are the slowest-growing corals in the world.
0:18:09 > 0:18:13But here they grow a remarkable two centimetres a year.
0:18:15 > 0:18:19To create a forest of them can take hundreds of years.
0:18:22 > 0:18:26Prehistoric shellfish, brachiopods,
0:18:26 > 0:18:29are relics from the time of the dinosaurs.
0:18:29 > 0:18:33They, too, have crept up the cliff walls and into the shallows.
0:18:39 > 0:18:43A unique mix of marine life has adapted to live here thanks
0:18:43 > 0:18:47to the extraordinary way fresh and saltwater meet.
0:19:00 > 0:19:05The south of New Zealand is one of the wettest places on earth.
0:19:14 > 0:19:17Freezing winds from Antarctica collide with warm wet weather
0:19:17 > 0:19:19from the north.
0:19:20 > 0:19:25Huge volumes of moist air are forced to rise over the South Island's
0:19:25 > 0:19:30mountains, where they cool and form vast banks of cloud.
0:19:35 > 0:19:39The South Island's west coast and forests are drenched with rain for
0:19:39 > 0:19:41more than 200 days a year.
0:19:45 > 0:19:50The water sustains vast swathes of temperate rainforest.
0:19:54 > 0:19:56Forests brought to life
0:19:56 > 0:19:59by New Zealand's bizarre and beautiful birds.
0:20:04 > 0:20:08Where tuis' complex calls echo through the canopy.
0:20:08 > 0:20:12TUIS SING
0:20:12 > 0:20:16Bellbirds trade nectar for a dusting of blue pollen.
0:20:19 > 0:20:24And flightless weka skulk in the undergrowth.
0:20:31 > 0:20:38It is the perfect environment for moisture-loving mosses and ferns.
0:20:50 > 0:20:52Underneath them,
0:20:52 > 0:20:58a humid forest floor of mucus and slime with a deadly secret.
0:21:09 > 0:21:14It comes to life at twilight when the hunters come out.
0:21:17 > 0:21:22Their lairs are in dark and damp forest overhangs where the extreme
0:21:22 > 0:21:24moisture is put to good use.
0:21:30 > 0:21:35These silken threads are the work of a tiny larva of a gnat.
0:21:36 > 0:21:41Beautiful though they may appear, the threads have a sinister purpose.
0:21:43 > 0:21:46The larvae use them to trap their prey.
0:21:55 > 0:21:59Droplets of sticky mucus work like spider webs,
0:21:59 > 0:22:02waiting to catch hold of flying insects.
0:22:08 > 0:22:11Mayflies are a particular favourite.
0:22:22 > 0:22:24As darkness settles,
0:22:24 > 0:22:30the genius of their deadly traps is revealed in all its beautiful glory.
0:22:38 > 0:22:42Gnat larvae are also known as glow-worms.
0:22:44 > 0:22:46The bioluminescence is generated
0:22:46 > 0:22:49by a chemical reaction within their tail.
0:22:53 > 0:22:58Creating an irresistible lure.
0:23:04 > 0:23:08The hungrier they are, the brighter they glow,
0:23:08 > 0:23:11drawing in victims like moths to a flame.
0:23:13 > 0:23:16And this glow-worm isn't alone.
0:23:27 > 0:23:29Hundreds live side-by-side.
0:23:44 > 0:23:50It's almost as if together they create their own starscape,
0:23:50 > 0:23:54confusing navigating insects and luring them to their doom.
0:24:27 > 0:24:30When the air itself becomes saturated
0:24:30 > 0:24:33and the temperature is just right,
0:24:33 > 0:24:35rare giants emerge.
0:24:52 > 0:24:55A powelliphanta snail.
0:24:55 > 0:24:57It can grow to the size of a man's fist.
0:25:06 > 0:25:11So rare, they can only be filmed in captivity
0:25:11 > 0:25:14where their extraordinary behaviour is revealed.
0:25:17 > 0:25:20It's still a mystery as to exactly how they track down their food.
0:25:22 > 0:25:26But one thing is for sure,
0:25:26 > 0:25:28this snail has unusual tastes.
0:25:30 > 0:25:33And revolting table manners.
0:26:25 > 0:26:30Its mouth envelops and suffocates the earthworm.
0:26:40 > 0:26:42It's sucked down like spaghetti.
0:27:01 > 0:27:07For anything bigger, it's got 6,000 teeth ready to shred the next meal.
0:27:12 > 0:27:15In this supersaturated environment,
0:27:15 > 0:27:20this specialised snail is the ultimate predator.
0:27:21 > 0:27:27BIRDS SING
0:27:31 > 0:27:34Water dominates the land.
0:27:39 > 0:27:43It thunders off the mountains, creating raging white-water rapids.
0:27:45 > 0:27:48Some of the South Island's mountain rivers flow
0:27:48 > 0:27:51at over 60,000 gallons a second.
0:27:55 > 0:27:58This is no place to bring up a family.
0:28:01 > 0:28:04But these parents have no choice.
0:28:18 > 0:28:22Fortunately, blue duck chicks are born ready.
0:28:33 > 0:28:35They have to navigate the churning currents
0:28:35 > 0:28:38to reach the best feeding grounds.
0:28:48 > 0:28:53And like their parents, they must dabble to feed.
0:28:53 > 0:28:55The tastiest food is on the rocks.
0:28:59 > 0:29:03Blue duck bills are specially-shaped to scrape
0:29:03 > 0:29:05insect larvae from the riverbed.
0:29:08 > 0:29:11The ducklings have a protective membrane to stop their bills
0:29:11 > 0:29:13being rubbed raw.
0:29:24 > 0:29:26It almost looks like fun.
0:29:34 > 0:29:37But sudden storms or snowmelt can cause flash floods...
0:29:41 > 0:29:45which can dislodge boulders, let alone a tiny ball of feathers.
0:29:57 > 0:30:02But these blue duck chicks can motor through this powerful flow.
0:30:06 > 0:30:09Their giant webbed feet are far too big on land,
0:30:09 > 0:30:12but they are perfect in the torrent.
0:30:26 > 0:30:30Allowing this violent river to become their playground.
0:30:44 > 0:30:48There is more than one way to conquer these extremes.
0:31:09 > 0:31:12Parrots are very intelligent birds.
0:31:12 > 0:31:16But the kea is perhaps the smartest of them all.
0:31:22 > 0:31:25When it comes to setting up home, they choose a warm,
0:31:25 > 0:31:28dry burrow to keep their family safe from the elements.
0:31:28 > 0:31:31HIGH-PITCHED SQUAWKING
0:31:36 > 0:31:39The chicks huddle together for warmth and comfort
0:31:39 > 0:31:41while their parents are away.
0:31:45 > 0:31:47But nine weeks after they've hatched,
0:31:47 > 0:31:49they hanker for something more.
0:31:54 > 0:31:59Kea are famous for their insatiable curiosity.
0:31:59 > 0:32:02THEY SQUAWK
0:32:04 > 0:32:07With a little parental encouragement,
0:32:07 > 0:32:09there's no holding these youngsters back.
0:32:17 > 0:32:20On broad wings, they are led out from the forest...
0:32:22 > 0:32:24into a whole new realm.
0:32:37 > 0:32:40Kea have unusually agile minds.
0:32:42 > 0:32:47Car parks and ski slopes are a smorgasbord of opportunity.
0:33:04 > 0:33:07It's not just their minds that are flexible.
0:33:09 > 0:33:12Their hooked beaks are a multi-tool.
0:33:21 > 0:33:26Perfect for digging, twisting, and getting into all kinds of mischief.
0:33:42 > 0:33:45It's this combination of beak and brain
0:33:45 > 0:33:50that enables kea to tackle even the most hostile face of the mountains.
0:34:04 > 0:34:08Its bill even serves as an ice axe.
0:34:14 > 0:34:19The kea is the only parrot in the world to thrive above the snow line.
0:34:44 > 0:34:46Of all the wild places in New Zealand,
0:34:46 > 0:34:50the Southern Alps present the most extreme challenges of all.
0:35:01 > 0:35:05They dictate the weather that rules all life here.
0:35:09 > 0:35:13They tower almost 4,000 metres above sea level
0:35:13 > 0:35:15and they're still rising.
0:35:18 > 0:35:21These are some of the fastest-growing mountains in the world.
0:35:27 > 0:35:32They might stand 20,000 metres high if they weren't battered down and
0:35:32 > 0:35:33eroded by the elements.
0:35:40 > 0:35:44It's a fractured, high altitude, frozen kingdom.
0:35:44 > 0:35:47The most inhospitable of all New Zealand.
0:35:53 > 0:35:57Up here, the grip of ice is impossible to escape.
0:35:59 > 0:36:02Heavy snow falls on heavy snow.
0:36:02 > 0:36:06It squeezes out the air, compacting into giant blocks of ice
0:36:06 > 0:36:08to create immense glaciers.
0:36:12 > 0:36:17Millions of tonnes of fresh water stored, frozen solid.
0:36:27 > 0:36:33These powerful giants carve out valleys and deep glacial lakes.
0:36:33 > 0:36:38They dominate the entire landscape and hold all life here in balance.
0:36:44 > 0:36:48But the strength of the South Island's glaciers is slipping,
0:36:48 > 0:36:53and one man has devoted his life's work to find out why.
0:37:03 > 0:37:06Brian Anderson is a glacial scientist
0:37:06 > 0:37:10who builds machines that help him look into the future.
0:37:15 > 0:37:16I like to get out to the mountains.
0:37:16 > 0:37:20I like to measure glaciers and try and understand how they work,
0:37:20 > 0:37:21what's happening at the moment,
0:37:21 > 0:37:23and then try and build a picture
0:37:23 > 0:37:25of what glaciers might do in the future.
0:37:32 > 0:37:37Brian's workplace has to be one of the most remote in the country.
0:37:42 > 0:37:46His mission forces him into parts of the wilderness so cut-off,
0:37:46 > 0:37:50he must take everything he needs with him.
0:38:07 > 0:38:09Brian has to drive a stake eight metres down
0:38:09 > 0:38:14into the icy heart of the glacier to reveal its deepest secrets.
0:38:16 > 0:38:19And he does it with this portable steam drill.
0:38:22 > 0:38:26For the steam drilling we use this backpack-mounted boiler.
0:38:26 > 0:38:28You have to drill quite deep.
0:38:28 > 0:38:31It might melt six or eight metres over the summer,
0:38:31 > 0:38:33and so we need our stakes to be long enough
0:38:33 > 0:38:34that they'll actually stay in.
0:38:36 > 0:38:39By measuring the depth of snow through the year,
0:38:39 > 0:38:43Brian can record how the glacier changes size,
0:38:43 > 0:38:46building a picture of its long-term behaviour.
0:38:55 > 0:38:58Glaciers move incredibly slowly,
0:38:58 > 0:39:02so the only way to watch them is to speed up time itself.
0:39:04 > 0:39:09And his handbuilt time-lapse units will let Brian do exactly that.
0:39:17 > 0:39:21Or they will, providing he can get them into the best positions.
0:39:28 > 0:39:32It all started with one camera and then I think I got seven cameras
0:39:32 > 0:39:35looking at glaciers around the Southern Alps.
0:39:35 > 0:39:39So the beauty of using a camera is that it's taking a photo every hour.
0:39:39 > 0:39:40It gives us the kind of data
0:39:40 > 0:39:42that you can't get from measuring on the ground.
0:39:42 > 0:39:45And you can't really get from measuring from space, either,
0:39:45 > 0:39:49because these glacier environments are often really cloudy.
0:39:54 > 0:39:58Time-lapse cameras can condense a year into a few seconds.
0:40:00 > 0:40:04But only if they survive the months of freezing conditions.
0:40:19 > 0:40:21The results are worth it.
0:40:26 > 0:40:28When you actually look at the photos,
0:40:28 > 0:40:31like every hour over weeks or months or years,
0:40:31 > 0:40:34you can actually see every little change in the glacier.
0:40:34 > 0:40:37I always find things that I wouldn't have expected.
0:40:41 > 0:40:43Glaciers are rivers of ice
0:40:43 > 0:40:47and it's only in time-lapse that we really see them flow.
0:40:53 > 0:40:58Some of the South Island's glaciers shift as much as seven metres a day.
0:41:08 > 0:41:11The meltwater helps them move.
0:41:11 > 0:41:15CREAKING
0:41:28 > 0:41:31It carves its way through to the base of the glacier.
0:41:43 > 0:41:47Where it lubricates the mass of ice,
0:41:47 > 0:41:49allowing it to flow.
0:41:52 > 0:41:54The huge weight carried by the water
0:41:54 > 0:41:58grinds its way down the valleys in colossal cascades.
0:42:07 > 0:42:11Brian is discovering that parts of New Zealand's frozen kingdom
0:42:11 > 0:42:13are melting away.
0:42:18 > 0:42:23Even the South Island's mightiest, the Tasman Glacier,
0:42:23 > 0:42:2716 miles long and 600 metres deep, is retreating.
0:42:31 > 0:42:35And the more they melt, the faster they flow.
0:42:41 > 0:42:43Scientists estimate that the Southern Alps
0:42:43 > 0:42:46have lost a third of their permanent snow and ice
0:42:46 > 0:42:48over the last 40 years.
0:43:03 > 0:43:06As the ice retreats, it reveals a broken landscape.
0:43:08 > 0:43:10A challenging place to get a foothold.
0:43:11 > 0:43:15But New Zealand has some remarkable mountaineers.
0:43:17 > 0:43:19It's alpine buttercup.
0:43:27 > 0:43:32At permanent risk of being destroyed by falling rocks.
0:43:37 > 0:43:42The secret to its survival lies beneath the scree -
0:43:42 > 0:43:45a snakelike stem which grows horizontally.
0:43:52 > 0:43:54This is its underground larder.
0:43:57 > 0:44:02If a stem is snapped, a whole new plant can still grow.
0:44:16 > 0:44:20Creating a shower of sunshine across the grey mountainside.
0:44:30 > 0:44:33And they aren't the only hardy plants up here.
0:44:38 > 0:44:43Edelweiss has its own fleecy blanket as insulation against the cold.
0:44:48 > 0:44:53And there is one plant which packs its leaves so tightly together
0:44:53 > 0:44:55they become a dense living carpet.
0:45:01 > 0:45:05Raoulia grows as low to the ground as possible, just off the rocks,
0:45:05 > 0:45:07where it can be a few degrees warmer,
0:45:07 > 0:45:10tucked away from the harsh mountain weather.
0:45:16 > 0:45:20Antarctic storms bring a sudden drop in temperature.
0:45:25 > 0:45:29Freezing conditions and gale-force winds bring death in their wake.
0:45:48 > 0:45:53To survive here, you have to be prepared to die here.
0:46:05 > 0:46:11But the sun can return as quickly as the storm arrived.
0:46:11 > 0:46:16And a rise of just a few degrees is enough to spark a thaw,
0:46:16 > 0:46:17even underground.
0:46:48 > 0:46:52Frozen solid, a mountain stone weta.
0:46:54 > 0:46:58It has the most extraordinary survival technique of all.
0:47:12 > 0:47:16The ability to come back from the dead.
0:47:21 > 0:47:24Only in a specialised filming chamber
0:47:24 > 0:47:27can we capture its extraordinary talent.
0:47:28 > 0:47:31The weta has developed special proteins which prevent
0:47:31 > 0:47:34ice crystals from forming inside its cells.
0:47:38 > 0:47:42A remarkable trick for a creature whose ancestors once lived in
0:47:42 > 0:47:44prehistoric warm, wet forests.
0:47:47 > 0:47:50But when New Zealand's mountains grew up beneath them,
0:47:50 > 0:47:53around five million years ago,
0:47:53 > 0:47:56they were forced to come up with this incredible ability to survive
0:47:56 > 0:47:57near lethal temperatures.
0:48:06 > 0:48:09Defrosting uses up a lot of energy.
0:48:16 > 0:48:20So mountain snow berries are a welcome sight.
0:48:25 > 0:48:28The weta needs to stock up while it can.
0:48:29 > 0:48:33The next Antarctic storm could be the return of winter.
0:48:55 > 0:48:58It can tolerate over 80% of its body freezing solid,
0:48:58 > 0:49:02and can do so day-in and day-out for weeks at a time.
0:49:13 > 0:49:19Nowhere else in New Zealand does life go to such extremes to survive.
0:49:26 > 0:49:29Every living thing here must rise
0:49:29 > 0:49:32to the challenges of this land's extremes.
0:49:38 > 0:49:40In the face of adversity,
0:49:40 > 0:49:44life has found unexpected and ingenious solutions.
0:49:47 > 0:49:50But perhaps most striking of all is their resilience.
0:49:53 > 0:49:59This is the true spirit of New Zealand's remarkable pioneers.
0:50:16 > 0:50:19Visitors to New Zealand's Southern Alps
0:50:19 > 0:50:23are likely to be confronted by a noisy welcoming party.
0:50:29 > 0:50:32Kea are the boldest characters in the mountains.
0:50:39 > 0:50:42Infamous for sticking their beaks into everything.
0:50:53 > 0:50:56These mischievous vandals know how to charm.
0:51:05 > 0:51:11But these entertaining encounters mask a worrying situation.
0:51:13 > 0:51:15Kea are slowly disappearing.
0:51:20 > 0:51:24One man is on a mission to find out why.
0:51:24 > 0:51:27I think something that people are unaware of
0:51:27 > 0:51:30is that kea are actually quite endangered, and there's not many.
0:51:30 > 0:51:33Corey Mosen is a kea fanatic.
0:51:35 > 0:51:37I think I like their inquisitive nature
0:51:37 > 0:51:40and how they're really cheeky.
0:51:40 > 0:51:43You know, they can outsmart you quite easily,
0:51:43 > 0:51:45and working with them is interesting every day.
0:51:48 > 0:51:51For nearly a decade, Cory has been trying
0:51:51 > 0:51:53to understand the kea's decline,
0:51:53 > 0:51:55and he doesn't do it alone.
0:51:55 > 0:51:57He has an assistant.
0:51:57 > 0:51:59Come here. Come here.
0:51:59 > 0:52:00His name's Ajax.
0:52:00 > 0:52:03I've been training the dog since he was a puppy.
0:52:03 > 0:52:05I've trained him to find kea nests.
0:52:05 > 0:52:09So he will follow a scent and lead me to where
0:52:09 > 0:52:12a kea is going in and out of a hole.
0:52:12 > 0:52:15Ajax is the only kea search dog in the world.
0:52:15 > 0:52:18AJAX BARKS
0:52:18 > 0:52:20He's pretty good company in the bush
0:52:20 > 0:52:22and he can keep up with me.
0:52:24 > 0:52:28Kea breed in some of the most remote parts of New Zealand.
0:52:31 > 0:52:36Today, Corey and Ajax are on their annual kea nest checkup,
0:52:36 > 0:52:38and have a two-day journey ahead of them.
0:52:38 > 0:52:42Sometimes you have to walk over a couple of mountains and down into
0:52:42 > 0:52:47valleys, and then up through some rivers and around some bluffs,
0:52:47 > 0:52:50but eventually you'll find where they are.
0:52:50 > 0:52:54But Corey's task is getting harder every year.
0:52:56 > 0:52:59He starts by checking some closer nesting sites.
0:53:01 > 0:53:04Which, a few years ago, would have been full of kea families.
0:53:06 > 0:53:08Now they're empty.
0:53:11 > 0:53:14Corey and Ajax are going to have to go further afield.
0:53:20 > 0:53:24With the light fading, they make camp for the night.
0:53:32 > 0:53:35My favourite thing is just being outside.
0:53:37 > 0:53:41I am outside all the time, in the snow, in the rain, in the wind,
0:53:41 > 0:53:44and it all just makes you feel alive.
0:53:56 > 0:53:58Next day, they set off early.
0:54:00 > 0:54:03And Ajax announces AJAX BARKS
0:54:03 > 0:54:05he's found exactly what they're looking for.
0:54:17 > 0:54:21But this burrow is built for a kea, not for a kea tracker.
0:54:23 > 0:54:26This is not comfortable.
0:54:29 > 0:54:32To study them, Corey first needs to catch them.
0:54:47 > 0:54:49A collar keeps Corey's fingers safe.
0:54:51 > 0:54:54He carefully attaches a leg ring
0:54:54 > 0:54:56and records the details.
0:55:00 > 0:55:04A quick draw of blood adds to the genetic database for the species.
0:55:05 > 0:55:10A final check, and he releases the bird back to the nest,
0:55:10 > 0:55:11none the worse for wear.
0:55:16 > 0:55:19But Corey has one more job to do.
0:55:23 > 0:55:26During the three months kea nest underground,
0:55:26 > 0:55:28they're extremely vulnerable.
0:55:30 > 0:55:32We put a trail camera outside the kea nest
0:55:32 > 0:55:35to monitor for predator visits.
0:55:35 > 0:55:39So every time something moves outside the nest,
0:55:39 > 0:55:41it'll take three photos,
0:55:41 > 0:55:44and we can use those photos to determine,
0:55:44 > 0:55:47you know, what's visiting the nests.
0:55:47 > 0:55:48Whether it's just the keas
0:55:48 > 0:55:52or whether stoats and possums and rats are annoying them, as well.
0:55:53 > 0:55:56Corey's trail-cams provide a unique insight
0:55:56 > 0:55:58into the private life of kea.
0:56:01 > 0:56:04But they also reveal what is really going on.
0:56:11 > 0:56:15Predatory mammals introduced from around the world
0:56:15 > 0:56:18are decimating New Zealand's native birds.
0:56:30 > 0:56:33Kea are easy prey for a stoat.
0:56:39 > 0:56:43I fear that they might be approaching extinction
0:56:43 > 0:56:47and that they will no longer be in the wild.
0:56:47 > 0:56:50We need to find a way to control stoats.
0:56:50 > 0:56:54Stoats are the big number-one pest that affect
0:56:54 > 0:56:57all New Zealand's native birds
0:56:57 > 0:57:00and if they weren't here, they'd do a lot better.
0:57:04 > 0:57:07In areas where there are pest control,
0:57:07 > 0:57:14the kea actually have a chance of producing young that make it out.
0:57:14 > 0:57:17It's great to see them become adults,
0:57:17 > 0:57:20flying around the same area where we tagged them as chicks.
0:57:24 > 0:57:27Oh, I'd like to see kea everywhere.
0:57:27 > 0:57:30Every time you go for a hike into the mountains
0:57:30 > 0:57:33it would be nice to have an interaction with a kea
0:57:33 > 0:57:35somewhere along the way
0:57:35 > 0:57:37and to hear them screaming in the hills
0:57:37 > 0:57:39and in the forest would be great.
0:57:41 > 0:57:43Thanks to Corey's hard work
0:57:43 > 0:57:50we are realising that despite their clever nature, kea need our help.
0:57:50 > 0:57:53And only with our help will New Zealand's Alpine valleys
0:57:53 > 0:57:57remain the realm of this cheeky mountain king.
0:58:02 > 0:58:05KEA SQUAWKS
0:58:08 > 0:58:10Next time...
0:58:10 > 0:58:13New opportunities transform New Zealand.
0:58:15 > 0:58:16A farmer's paradise...
0:58:18 > 0:58:19a fisherman's dream...
0:58:22 > 0:58:24and a playground for new arrivals.
0:58:26 > 0:58:29The home of world-renowned conservation...
0:58:31 > 0:58:36where a flightless parrot discovers fame.