0:00:02 > 0:00:04They call it America's last frontier.
0:00:07 > 0:00:10Half a million square miles of wilderness.
0:00:12 > 0:00:15This is Alaska.
0:00:17 > 0:00:21Home to some of the hardiest animals on the planet.
0:00:23 > 0:00:25LOUD CALLS
0:00:27 > 0:00:30Alaskan seasons run fast and furious.
0:00:39 > 0:00:41Opportunities are fleeting...
0:00:43 > 0:00:46..for people as well as animals.
0:00:47 > 0:00:50Survival means making the most of nature's gold rush.
0:00:52 > 0:00:53Play it right...
0:00:53 > 0:00:56and you'll hit the jackpot.
0:00:56 > 0:00:58- Get it wrong... - CHIRPING
0:00:58 > 0:01:00- ..and you could lose it all. - SQUAWKING
0:01:00 > 0:01:02TWEETING
0:01:03 > 0:01:06It's not about your size.
0:01:06 > 0:01:07It's about your attitude.
0:01:08 > 0:01:11This land belongs to the bold.
0:01:11 > 0:01:13GROWLING
0:01:13 > 0:01:16- This is Alaska. - ROARING
0:01:33 > 0:01:36The rising warmth of the spring sun
0:01:36 > 0:01:38has unlocked Alaska from the chill of winter.
0:01:42 > 0:01:46The land has thawed and the rivers are flowing again.
0:01:48 > 0:01:50It has become a land of promise.
0:01:50 > 0:01:53SOFT WHINING
0:01:54 > 0:01:57Now summer must deliver on that promise.
0:02:00 > 0:02:02And it will have to be quick.
0:02:02 > 0:02:06Alaska's summer days are crazy long,
0:02:06 > 0:02:08but the season flies by.
0:02:17 > 0:02:19Alaska is so big,
0:02:19 > 0:02:23the seasons are staggered as they sweep up the state.
0:02:25 > 0:02:29It's in the far south-eastern corner where summer first reappears.
0:02:34 > 0:02:37Down here, wedged between the Pacific Ocean
0:02:37 > 0:02:41and the southern coast mountains, there's an enormous rainforest.
0:02:44 > 0:02:49This is Tongass, part of the biggest temperate rainforest in the world.
0:02:54 > 0:03:00In May, just as summer arrives, so does a tough little visitor.
0:03:00 > 0:03:04One that has made a 4,000-mile journey all the way from Mexico,
0:03:04 > 0:03:07confident that Alaska will deliver.
0:03:09 > 0:03:11SOFT TWEETS
0:03:12 > 0:03:16A rufous hummingbird - the first sign of summer.
0:03:18 > 0:03:22She only weighs 4g, not much more than a penny coin.
0:03:28 > 0:03:31There are no other hummingbirds in Alaska,
0:03:31 > 0:03:35so it's worth the endurance flight to get here.
0:03:35 > 0:03:36There's less competition.
0:03:41 > 0:03:44She's come here to feed on Alaska's summer flowers.
0:03:47 > 0:03:49But she seems to have arrived too early.
0:03:53 > 0:03:58With 60 wing flaps a second, she's burning up the calories fast.
0:04:00 > 0:04:01She needs to refuel.
0:04:06 > 0:04:10Acre for acre, this forest has more organic matter in it
0:04:10 > 0:04:12than any other forest on Earth.
0:04:15 > 0:04:17There's plenty of food round here,
0:04:17 > 0:04:19if she's cunning enough to find it.
0:04:33 > 0:04:37Every day, the sun is staying in the sky an extra ten minutes.
0:04:38 > 0:04:42And as the days get longer, the opportunities get bigger.
0:04:48 > 0:04:52At Katmai, along the southern coast,
0:04:52 > 0:04:55speculators have been coming down from the mountains.
0:04:58 > 0:05:00BIRDS CALL
0:05:01 > 0:05:03GROWLING
0:05:03 > 0:05:05Grizzly bears.
0:05:05 > 0:05:07They sleep hard through the seven months of winter,
0:05:07 > 0:05:10but their summers are intense.
0:05:10 > 0:05:12SNARLING
0:05:12 > 0:05:15ROARING AND GROWLING
0:05:19 > 0:05:21Whilst the males work out who's boss,
0:05:21 > 0:05:25this female is more interested in finding something to eat.
0:05:25 > 0:05:29She's lost over a third of her body weight during winter,
0:05:29 > 0:05:32and, right now, there's not much around except grass.
0:05:35 > 0:05:37A pumped-up male could kill her cub.
0:05:40 > 0:05:41GROWLING
0:05:41 > 0:05:43But it's worth the risk to come here.
0:05:47 > 0:05:49The bears of this coast are all here
0:05:49 > 0:05:52because a feast is about to be delivered from the ocean.
0:05:54 > 0:05:56GULLS CALL
0:05:59 > 0:06:01Not that there's any sign of it yet.
0:06:09 > 0:06:11There is something else to eat on the beach...
0:06:12 > 0:06:15..but it will only be available when the tide goes out.
0:06:20 > 0:06:21It's under their feet.
0:06:25 > 0:06:28They can smell it.
0:06:28 > 0:06:30SNIFFING
0:06:46 > 0:06:47A clam.
0:06:47 > 0:06:49It may not look like much,
0:06:49 > 0:06:51but this seafood is rich.
0:06:53 > 0:06:56And these six mile-long mud flats are full of them.
0:07:18 > 0:07:20It's not as easy as it looks.
0:07:21 > 0:07:26All the while, the clams are escaping downwards through the sand.
0:07:26 > 0:07:29Sometimes, they move faster than a little bear can dig.
0:07:33 > 0:07:35IT ROARS
0:07:39 > 0:07:44A 130kg grizzly mum needs to find a couple of hundred clams a day,
0:07:44 > 0:07:46to make it worth the effort.
0:07:48 > 0:07:49But it all helps to keep them going
0:07:49 > 0:07:52until the first real feast of summer arrives.
0:08:00 > 0:08:05The forest takes its cues from the strengthening sunlight,
0:08:05 > 0:08:08but it's still too early for the nectar-rich flowers.
0:08:11 > 0:08:14The hummingbird must eat every 20 minutes
0:08:14 > 0:08:16or run out of energy altogether.
0:08:21 > 0:08:24But she's been coming to this forest every summer,
0:08:24 > 0:08:26and she knows a few tricks.
0:08:26 > 0:08:29TAPPING
0:08:29 > 0:08:33A distinctive tapping noise signals just what she's been looking for.
0:08:39 > 0:08:41A red-breasted sapsucker.
0:08:45 > 0:08:48He's carefully chiselling holes in the tree-trunk,
0:08:48 > 0:08:50so the tree's sweet syrup leaks out.
0:08:55 > 0:08:58He'll be back later to feed, once the sap is flowing well.
0:09:02 > 0:09:06It's the chance the hummingbird has been waiting for.
0:09:06 > 0:09:08TAPPING CONTINUES
0:09:09 > 0:09:12She just needs to get in unnoticed...
0:09:14 > 0:09:17..while the sapsucker is busy at another tree.
0:09:23 > 0:09:25It's all about timing.
0:09:33 > 0:09:36The sugary sap is starting to overflow.
0:09:38 > 0:09:40It's now or never.
0:09:49 > 0:09:52Her tongue curls, grasping the sap,
0:09:52 > 0:09:54licking it in at nine sips a second.
0:09:58 > 0:10:01She can drink more than her body weight every day.
0:10:04 > 0:10:09Over the next three weeks, she'll be back regularly to pilfer this store.
0:10:12 > 0:10:15GULLS CALL
0:10:17 > 0:10:21The Alaska summer is poised to release its bounty.
0:10:28 > 0:10:32At Katmai, the grizzly bears are getting restless.
0:10:42 > 0:10:45Their enterprising ways have kept them going,
0:10:45 > 0:10:48but there are only so many clams you can eat.
0:10:50 > 0:10:53They really need something more substantial.
0:10:56 > 0:10:59It's not just the bears that are waiting.
0:11:00 > 0:11:03Just off the south west coast, at Bristol Bay,
0:11:03 > 0:11:06Alaska's fishermen are also gathering.
0:11:09 > 0:11:131,500 boats are here in anticipation
0:11:13 > 0:11:15of the biggest fishing event of the summer.
0:11:20 > 0:11:22The return of the salmon.
0:11:25 > 0:11:29300 million salmon will swim towards Alaska's shores
0:11:29 > 0:11:34over the summer months, and these fishermen are right in their path.
0:11:36 > 0:11:40Alaska has the greatest runs of wild salmon in the world.
0:11:41 > 0:11:42And Bristol Bay is the world's
0:11:42 > 0:11:45most profitable salmon fishery of them all.
0:11:45 > 0:11:47HORN BLOWS
0:11:47 > 0:11:50Everyone fights to be in the hot spot.
0:11:57 > 0:12:01In this bay alone, they catch 30 million salmon in one season.
0:12:06 > 0:12:09The millions that escape the fishermen's nets
0:12:09 > 0:12:11push onwards to the coast.
0:12:11 > 0:12:15And, for the grizzly bears, the wait is finally over.
0:12:25 > 0:12:28These fish are in prime condition...
0:12:29 > 0:12:32..well fed and muscled from two years at sea.
0:12:34 > 0:12:38The bears couldn't ask for a more bountiful feast.
0:12:43 > 0:12:46They gorge themselves on 40kg a day.
0:12:48 > 0:12:49It's a race to feed up.
0:13:12 > 0:13:15Katmai has one of the densest grizzly bear populations
0:13:15 > 0:13:19in the world, but there's still plenty to go round.
0:13:23 > 0:13:27Mums bring their cubs to the places they remember from their own youth.
0:13:28 > 0:13:31And where their own mothers first taught them to fish.
0:13:50 > 0:13:52The fish are so plentiful,
0:13:52 > 0:13:55they often won't even bother eating the whole thing.
0:13:55 > 0:13:57They just chew off the fattiest parts -
0:13:57 > 0:14:00the skin and the brain - and ignore the rest.
0:14:04 > 0:14:07However, Mum's half always seems to look tastier.
0:14:12 > 0:14:14GULLS CALL
0:14:27 > 0:14:32Colossal runs of coho, sockeye, chum, pink and Chinook salmon
0:14:32 > 0:14:34battle their way through shallows,
0:14:34 > 0:14:37past bears and into the rivers beyond.
0:14:42 > 0:14:44It's just the start of their journey.
0:14:52 > 0:14:55Tens of millions of salmon migrate upstream.
0:15:06 > 0:15:09On and on they swim, deep into the heart of Alaska,
0:15:09 > 0:15:13following the scent of the river to find their way home.
0:15:18 > 0:15:20Of all the salmon in the world,
0:15:20 > 0:15:23the ones that travel furthest are the coho and Chinook
0:15:23 > 0:15:28that migrate up the mighty Yukon River, 2,000 miles inland.
0:15:37 > 0:15:41But 800 miles in, they hit another obstacle.
0:15:41 > 0:15:44It's something you would only find in Alaska.
0:15:56 > 0:15:57A fish wheel.
0:16:01 > 0:16:04It belongs to Lester Erhart,
0:16:04 > 0:16:07a native Alaskan, who has lived on the Yukon his entire life.
0:16:12 > 0:16:14It's my home.
0:16:14 > 0:16:16It's my home, right here.
0:16:16 > 0:16:18I love it.
0:16:18 > 0:16:21Lester spent the winter building the wheel by hand.
0:16:21 > 0:16:23Now he's set it up in the river,
0:16:23 > 0:16:26just in time for the return of the salmon.
0:16:26 > 0:16:28BOAT ENGINE PURRS
0:16:30 > 0:16:32Powered only by the current,
0:16:32 > 0:16:35the wheel turns to the rhythm of the river.
0:16:37 > 0:16:40As the salmon pass, they are scooped out of the water.
0:16:45 > 0:16:48Three million Salmon travel up the Yukon during summer.
0:16:52 > 0:16:55The wheel only works in a river this full of salmon.
0:17:00 > 0:17:04All Lester has to do is collect the fish from the box.
0:17:04 > 0:17:06It's brilliantly simple.
0:17:08 > 0:17:11There was this young boy, about 14 years old,
0:17:11 > 0:17:15and he came up and he looked in that box and saw all that fish.
0:17:18 > 0:17:22He said to me, "You've got the right way to fish."
0:17:22 > 0:17:23HE LAUGHS
0:17:30 > 0:17:34This is the easy way to do things! HE LAUGHS
0:17:39 > 0:17:41Lester can catch hundreds of fish a day.
0:17:47 > 0:17:52Under the warm sun, the Alaskan summer has delivered a bonanza.
0:17:59 > 0:18:02A third of Alaska sits above the Arctic Circle.
0:18:03 > 0:18:05At the top of the world,
0:18:05 > 0:18:09it's the last place to feel the warmth of summer.
0:18:09 > 0:18:12But by June, this treeless land, the tundra,
0:18:12 > 0:18:14is tipped towards the sun,
0:18:14 > 0:18:17bathing it in 24-hour daylight.
0:18:22 > 0:18:24At Alaska's most northerly point,
0:18:24 > 0:18:27the sun rose at the beginning of May and won't set until August.
0:18:30 > 0:18:33Summer in the Arctic becomes one endless day.
0:18:36 > 0:18:39But you can have too much of a good thing.
0:18:44 > 0:18:47It's now, in these odd conditions,
0:18:47 > 0:18:50that a snowy owl is raising her family.
0:18:55 > 0:18:59In the absence of any trees up here, she has to nest on the ground.
0:19:04 > 0:19:08She has three growing chicks, and broods them 24 hours a day.
0:19:14 > 0:19:16As she can't leave them, Dad will provide.
0:19:24 > 0:19:25SQUAWKING
0:19:31 > 0:19:33CHICK SQUEAKS
0:19:47 > 0:19:49At first glance,
0:19:49 > 0:19:52the tundra doesn't seem to be exactly brimming with food.
0:19:55 > 0:19:57But it is, if you know where to look.
0:20:06 > 0:20:08Lemmings.
0:20:08 > 0:20:11They eat the grasses and shrubs that cover the landscape.
0:20:15 > 0:20:19With the unlimited food here, they breed fast and, within a few weeks,
0:20:19 > 0:20:22there can be millions of them,
0:20:22 > 0:20:24exactly what Dad wants to see.
0:20:27 > 0:20:29He just needs to choose his victim.
0:20:32 > 0:20:34HIGH-PITCHED CALL
0:20:50 > 0:20:52But one little lemming
0:20:52 > 0:20:55is not going to go very far with his growing family.
0:20:58 > 0:21:01These are North America's heaviest owls.
0:21:01 > 0:21:04Each chick alone can eat three lemmings a day.
0:21:12 > 0:21:17Hunting 24 hours a day, it doesn't take him long to satisfy everyone.
0:21:21 > 0:21:25But it's as if the glut of lemmings has tripped his brain.
0:21:37 > 0:21:42With no darkness to tell him when to rest, he just goes on and on.
0:21:46 > 0:21:48The chicks are full to bursting...
0:21:50 > 0:21:52..but still the lemmings keep on piling up.
0:22:07 > 0:22:11Now his offerings aren't met with quite the same enthusiasm.
0:22:24 > 0:22:29By the summer solstice, the sun's unblinking gaze is most intense.
0:22:30 > 0:22:35Temperatures can climb over 30 degrees Celsius.
0:22:35 > 0:22:39That's 80 degrees warmer than it was just three months earlier.
0:22:42 > 0:22:45On the tundra, there's not a scrap of shade.
0:22:52 > 0:22:55This female caribou left her herd eight weeks ago,
0:22:55 > 0:22:57when she was due to calve.
0:23:00 > 0:23:03It's easier to hide from predators when there are just two of you.
0:23:24 > 0:23:28Her calf doubled in size in its first two weeks,
0:23:28 > 0:23:31and now it's strong enough to join the herd.
0:23:31 > 0:23:35It will spend the rest of its life on the move,
0:23:35 > 0:23:37just one of 40,000.
0:23:40 > 0:23:42SOFT GRUNTING
0:23:48 > 0:23:50It's the middle of the night.
0:23:59 > 0:24:01The caribou have reached the lake.
0:24:04 > 0:24:06It's drawn in others from miles around.
0:24:11 > 0:24:13It's not just a place to drink.
0:24:17 > 0:24:19Buried in the mud at the bottom of the lake,
0:24:19 > 0:24:23there are mineral salts, calcium, magnesium and sodium
0:24:23 > 0:24:26vital for the caribous' health.
0:24:29 > 0:24:33They stir up the mud with their feet and drink the solution.
0:24:52 > 0:24:57Just beneath the surface of the water, an army is being mobilised.
0:25:02 > 0:25:05The tundra offers the perfect growing conditions
0:25:05 > 0:25:06for insect larvae.
0:25:08 > 0:25:11Shallow pools, left over from melting ice,
0:25:11 > 0:25:13warm up quickly in the summer sun.
0:25:18 > 0:25:23Just eight days after hatching, they start to emerge as adults.
0:25:58 > 0:26:01These are animals so well adapted
0:26:01 > 0:26:04that they haven't changed in 40 million years.
0:26:07 > 0:26:10BUZZING
0:26:16 > 0:26:18Mosquitoes.
0:26:18 > 0:26:21Literally trillions of them.
0:26:21 > 0:26:23And hungry for blood.
0:26:27 > 0:26:30BUZZING, GRUNTING
0:26:33 > 0:26:36They are so big and ferocious,
0:26:36 > 0:26:39the locals jokingly call them Alaska's state bird.
0:26:41 > 0:26:43It is said they can form swarms thick enough
0:26:43 > 0:26:45to asphyxiate a caribou.
0:26:47 > 0:26:51Each animal can lose up to half a pint of blood a day.
0:26:51 > 0:26:54It's enough to drive anyone mad.
0:26:54 > 0:26:56BUZZING CONTINUES
0:27:07 > 0:27:10The only defence they have is to move.
0:27:22 > 0:27:25There will be no rest for this calf this summer.
0:27:27 > 0:27:31He has just joined the longest land mammal migration in the world.
0:27:36 > 0:27:40The herds are so big, they etch trails across the land.
0:27:44 > 0:27:47All over Alaska, caribou are on an endless quest,
0:27:47 > 0:27:49searching for fresh grazing...
0:27:49 > 0:27:50BUZZING
0:27:50 > 0:27:53..all the while being driven on by mosquitoes.
0:28:03 > 0:28:06Alaska has more caribou than people.
0:28:07 > 0:28:10Over 750,000 of them crisscross the state
0:28:10 > 0:28:13covering thousands of miles in just a few months.
0:28:23 > 0:28:27In the far north west, the caribou migration path
0:28:27 > 0:28:31skirts round one of the most unexpected landscapes on the planet.
0:28:42 > 0:28:46Here, 40 miles above the Arctic Circle,
0:28:46 > 0:28:49there's a sun-scorched dune field.
0:28:59 > 0:29:00At the height of summer,
0:29:00 > 0:29:04temperatures here can reach 34 degrees Celsius.
0:29:06 > 0:29:09It's about as hot as Alaska gets.
0:29:10 > 0:29:14The annual rainfall here is less than the Grand Canyon.
0:29:26 > 0:29:29The Kobuk Dunes are a footprint of the glaciers
0:29:29 > 0:29:34that scraped across northern Alaska over hundreds of thousands of years.
0:29:49 > 0:29:51As the glaciers retreated,
0:29:51 > 0:29:55arctic winds picked up the grains of eroded sediment they'd left behind.
0:29:56 > 0:30:00They whipped them up into dunes, some more than 30 metres high.
0:30:01 > 0:30:06It's the largest active dune field in the whole United States.
0:30:06 > 0:30:07But it's shrinking.
0:30:09 > 0:30:14The vast banks of sand are slowly being infiltrated by trees.
0:30:14 > 0:30:18Eventually, these ancient dunes will vanish
0:30:18 > 0:30:20as the forests take them back.
0:30:27 > 0:30:30These black spruce forests dominate interior Alaska.
0:30:32 > 0:30:36They're desiccated by the heat and wind of summer and full of resin.
0:30:42 > 0:30:45It doesn't take much to set the whole thing alight.
0:31:08 > 0:31:13Every summer, around 500 major fires break out in Alaska's heart.
0:31:15 > 0:31:19Left unchecked, wildfire can rip through 300 square miles a day.
0:31:24 > 0:31:27There are very few roads across Alaska.
0:31:27 > 0:31:31There's only one way to control a big fire in this vast wilderness -
0:31:31 > 0:31:33from above.
0:31:36 > 0:31:40It takes a crack team of firefighters to do this job.
0:31:40 > 0:31:43They're drafted in from all across America
0:31:43 > 0:31:47and specially trained for fighting fires Alaskan-style
0:31:47 > 0:31:49because this plane isn't going to land.
0:31:49 > 0:31:51Jumpers away.
0:31:51 > 0:31:54Three, two, one, jump!
0:31:57 > 0:31:59Jump!
0:32:04 > 0:32:07These are Alaska's Smokejumpers.
0:32:08 > 0:32:12All through the summer, they are the state's first line of defence.
0:32:23 > 0:32:27A wildfire burns at 800 degrees Celsius
0:32:27 > 0:32:30and can rage for weeks.
0:32:30 > 0:32:33A Smokejumper's job is to stop the fire
0:32:33 > 0:32:35before it gets too big to stop.
0:32:41 > 0:32:43All right, ready for water. Turn that water back on.
0:32:43 > 0:32:46Water coming to you.
0:32:54 > 0:32:56RADIO: Just a quick update on the fire,
0:32:56 > 0:32:59we'd like to call it contained.
0:32:59 > 0:33:03It's hard to see a blaze like this as anything other than a disaster.
0:33:05 > 0:33:08But Alaska's forests have been living with wildfire
0:33:08 > 0:33:11for hundreds of thousands of years.
0:33:11 > 0:33:14They've evolved not only to cope, but to benefit.
0:33:18 > 0:33:22As long as black spruce cones are not totally torched,
0:33:22 > 0:33:24the heat will open them up,
0:33:24 > 0:33:27letting their seeds drop into a bed of fertile ash.
0:33:38 > 0:33:42Sunlight brings a flush of new greenery to the forest floor.
0:33:43 > 0:33:46These plant pioneers now have full access
0:33:46 > 0:33:48to the endless summer sunshine.
0:33:52 > 0:33:57Fireweed is the first to stake its claim.
0:33:57 > 0:33:59It flowers through the hazy days
0:33:59 > 0:34:03and Alaskans call it summer's timekeeper.
0:34:03 > 0:34:07The flowers unfold from the bottom of the plant.
0:34:07 > 0:34:10When they reach the top, that's the end of summer.
0:34:14 > 0:34:17It's a warning that, despite the summer heat,
0:34:17 > 0:34:20the first snows of winter are only weeks away.
0:34:25 > 0:34:27High up in the Talkeetna Mountains,
0:34:27 > 0:34:30there's one Alaskan who's already prepared.
0:34:35 > 0:34:37The collared pika.
0:34:39 > 0:34:40COLLARED PIKA SQUEAKS
0:34:40 > 0:34:43He's spent his entire summer hard at work.
0:34:47 > 0:34:48When the winter comes,
0:34:48 > 0:34:52his favourite grasses and sedges will be buried under the snow.
0:34:57 > 0:34:58But he's not worried.
0:34:58 > 0:35:02He's been saving food for the lean months ahead.
0:35:02 > 0:35:03COLLARED PIKA SQUEAKS
0:35:18 > 0:35:21Hidden among the rocks is his winter larder.
0:35:24 > 0:35:28He's carefully positioned it to catch the sun's rays,
0:35:28 > 0:35:30which dry and cure his supply.
0:35:31 > 0:35:34WIND HOWLS
0:35:35 > 0:35:38Half a metre wide and 30cm deep,
0:35:38 > 0:35:41this haystack is his survival rations.
0:35:49 > 0:35:52He's chosen the contents meticulously.
0:35:56 > 0:35:59He's picked some toxic plants,
0:35:59 > 0:36:03these will decompose slower and keep food for eating fresher for longer.
0:36:15 > 0:36:18COLLARED PIKA SQUEAKS
0:36:18 > 0:36:22Like all Alaskans, he knows that winter preparations start early.
0:36:24 > 0:36:27And you have to make the most of summer's bounty.
0:36:29 > 0:36:31The sun is getting lower.
0:36:31 > 0:36:33Summer is drawing to a close.
0:36:40 > 0:36:46But rather than mourn its passing, Alaskans celebrate its generosity.
0:36:46 > 0:36:50SCREAMS OF LAUGHTER
0:37:00 > 0:37:01The Alaska State Fair
0:37:01 > 0:37:06attracts more than a third of the entire population through its gates.
0:37:06 > 0:37:10For 12 days from the end of August to Labor Day,
0:37:10 > 0:37:12it's summer's final fling.
0:37:17 > 0:37:22And the star attraction - the giant vegetable competition.
0:37:22 > 0:37:25With 100 days of near endless sunlight,
0:37:25 > 0:37:28you can grow record-breakers.
0:37:28 > 0:37:32Cabbages heavier than a large child, supersized broccoli,
0:37:32 > 0:37:34monster beans.
0:37:38 > 0:37:41It's this high art of growing giants
0:37:41 > 0:37:43that has kept Dale Marshall busy all summer long.
0:37:51 > 0:37:55Well, we took our circumference, which was 190,
0:37:55 > 0:37:56so then when you look on our chart here,
0:37:56 > 0:38:01it tells you our estimated weight is 1,343lbs.
0:38:01 > 0:38:02It could go heavier, it could go lighter,
0:38:02 > 0:38:05but even if it goes a bit lighter, I've got a little buffer there.
0:38:05 > 0:38:08So I'm hoping that we have a new state record here.
0:38:10 > 0:38:14Dale has been harnessing the sun's power to nurture a giant.
0:38:17 > 0:38:21A giant that's been growing 10kg a day
0:38:21 > 0:38:25and has tendrils more than 20 metres long.
0:38:25 > 0:38:27Dale has been growing a giant...
0:38:29 > 0:38:31..pumpkin.
0:38:38 > 0:38:39Don't really take any long vacations
0:38:39 > 0:38:44or go out of state at all in the summertime here, you know.
0:38:44 > 0:38:46So you try to make your travel plans,
0:38:46 > 0:38:49you know, in the off pumpkin season so to speak.
0:38:57 > 0:39:01Dale has spent three hours every day, all summer,
0:39:01 > 0:39:04creating a monster.
0:39:04 > 0:39:07As the plant get bigger, you've got to keep doing it more
0:39:07 > 0:39:09cos there's more things to prune.
0:39:09 > 0:39:13After a while it's just bleh!
0:39:14 > 0:39:17It's big.
0:39:17 > 0:39:19But to find out if it's a world-beater,
0:39:19 > 0:39:22he needs to take it to the State Fair.
0:39:26 > 0:39:29Just getting it there is a feat in itself.
0:39:34 > 0:39:36Lifting a vegetable the weight of a small car
0:39:36 > 0:39:39takes more than a wheelbarrow.
0:39:44 > 0:39:46And we're done, we're separated!
0:39:55 > 0:39:57We're ready to roll!
0:39:57 > 0:40:01This is the most nerve-racking time for Dale.
0:40:01 > 0:40:03You have to go up off the ground.
0:40:03 > 0:40:06- Listen to it.- Yeah. - PUMPKIN CREAKS
0:40:06 > 0:40:09Holy cow, look at it. Look at that thing strain now!
0:40:11 > 0:40:14This pumpkin represents hundreds of hours of work
0:40:14 > 0:40:17and thousands of hours of sunshine.
0:40:20 > 0:40:23Damaging it would mean disqualification.
0:40:26 > 0:40:27Oh, that looks beautiful!
0:40:29 > 0:40:32Where do you want the vine going?
0:40:32 > 0:40:34Touchdown!
0:40:37 > 0:40:40- ANNOUNCER:- 'In the United States, we have a special award
0:40:40 > 0:40:42'for the most beautiful orange pumpkin...'
0:40:42 > 0:40:46At the fairground, everyone is gathering for the main event.
0:40:46 > 0:40:50'..in a lot of the State Fairs. We wanted to make sure
0:40:50 > 0:40:54'that beautiful orange pumpkin colour was recognised.
0:40:54 > 0:40:56'Here we go!
0:40:56 > 0:41:00'She said, "Put it on the scale!" Let's see where this goes.
0:41:00 > 0:41:04- APPLAUSE AND CHEERING - 'All right, everybody, think heavy!
0:41:06 > 0:41:08'Here we go.'
0:41:10 > 0:41:12All right, come on!
0:41:12 > 0:41:14Dale has come close before,
0:41:14 > 0:41:16but he's never broken the State record.
0:41:16 > 0:41:22That record stands at 1,287lbs.
0:41:22 > 0:41:241,283!
0:41:24 > 0:41:27- Is that what that is? - That's what it is.
0:41:27 > 0:41:311,283lbs!
0:41:31 > 0:41:33Great effort!
0:41:40 > 0:41:434lbs off!
0:41:43 > 0:41:46The sun has set on this year's competition.
0:41:52 > 0:41:55But Dale doesn't waste time.
0:41:56 > 0:42:00He collects the seeds and starts planning next year's pumpkin.
0:42:07 > 0:42:11In Katmai, the grizzly bears are still catching fish.
0:42:13 > 0:42:18A bear can eat a ton and a half of salmon over a good season.
0:42:18 > 0:42:22It's what makes Alaskan bears the biggest in the world.
0:42:26 > 0:42:28But the run is coming to an end.
0:42:35 > 0:42:38By October, all these bears will head for the hills
0:42:38 > 0:42:41and get ready to sleep out the winter.
0:42:44 > 0:42:46Thanks to the wealth of fish,
0:42:46 > 0:42:49they'll go into their dens 90kg heavier then they came out.
0:42:55 > 0:42:58All across this super-sized state,
0:42:58 > 0:43:01everyone has been cashing in on the abundance of summer.
0:43:09 > 0:43:11Good grazing has allowed this bull moose
0:43:11 > 0:43:14to grow something enormous of his own.
0:43:15 > 0:43:18Something he hopes is going to get him noticed.
0:43:23 > 0:43:27MOOSE GRUNTS
0:43:30 > 0:43:34Two-meter-wide antlers.
0:43:34 > 0:43:38At their peak, the bone was growing at 2cm a day.
0:43:38 > 0:43:42They're the fastest growing organ in the natural world.
0:43:52 > 0:43:56And during all this time, they have been completely...
0:43:56 > 0:43:58useless.
0:44:02 > 0:44:03Until now.
0:44:06 > 0:44:09As the days get shorter and the sunlight weaker,
0:44:09 > 0:44:12moose turn their mind to just one thing.
0:44:17 > 0:44:20The annual rut.
0:44:23 > 0:44:27MOOSE GRUNT
0:44:27 > 0:44:30Young male upstarts test their strength against each other
0:44:30 > 0:44:33with their puny headgear.
0:44:44 > 0:44:46Hormones are raging.
0:44:46 > 0:44:49For two weeks, they don't even stop to eat.
0:44:49 > 0:44:53Each male is doing his best to stand out from the crowd.
0:44:56 > 0:44:59But this big male is going to let his antlers do the talking.
0:45:01 > 0:45:04And they're already causing quite a stir.
0:45:06 > 0:45:11As a male moose gets older, his antlers get bigger and more ornate.
0:45:11 > 0:45:12Now he's in his prime,
0:45:12 > 0:45:16they're as big and as pointy as they're ever going to get.
0:45:17 > 0:45:19No male will challenge him.
0:45:21 > 0:45:25MOOSE GRUNTS
0:45:26 > 0:45:29And he has the full attention of the female.
0:45:34 > 0:45:36MOOSE GRUNT
0:45:36 > 0:45:40While the young bucks carry on sparring,
0:45:40 > 0:45:42he just has to do one simple thing.
0:45:46 > 0:45:49He digs a pit and leaves his scent.
0:45:52 > 0:45:54MOOSE URINATES
0:45:54 > 0:45:58The pheromones released further advertise his machismo.
0:45:58 > 0:46:01The whole package makes him irresistible.
0:46:01 > 0:46:06MOOSE CONTINUES URINATING
0:46:11 > 0:46:15In Alaska, they say that when it comes to finding a man,
0:46:15 > 0:46:17the odds are good.
0:46:17 > 0:46:19But the goods are often odd.
0:46:22 > 0:46:25But with a headset this big, he's a keeper.
0:46:35 > 0:46:37The sun's power has waned.
0:46:37 > 0:46:39It's autumn.
0:46:39 > 0:46:42Darkness steals another six minutes each day.
0:46:52 > 0:46:55It's been a good summer for Lester.
0:46:56 > 0:47:00His fishwheel has delivered him thousands of Coho salmon.
0:47:02 > 0:47:05This will feed me in the winter and everybody else,
0:47:05 > 0:47:08pretty near everybody.
0:47:08 > 0:47:10Now he has to gut and fillet the fish.
0:47:12 > 0:47:15He hangs it in the sun to dry and cure...
0:47:18 > 0:47:21..and then he takes it into his home-built smokehouse.
0:47:27 > 0:47:31The art of preserving fish has been in Alaska for thousands of years.
0:47:36 > 0:47:38It's been passed down the generations
0:47:38 > 0:47:42and it has allowed Alaskans to carry the bounty of summer
0:47:42 > 0:47:44into the scarcity of winter.
0:47:46 > 0:47:50It's knowledge that reached Lester as a boy.
0:47:50 > 0:47:53It's helped him feed his family for 60 years.
0:47:58 > 0:48:01He's in no hurry to change his ways.
0:48:02 > 0:48:05I tried the other life and...
0:48:05 > 0:48:07I like this life better.
0:48:15 > 0:48:18In a few weeks, the mighty Yukon,
0:48:18 > 0:48:21the river that brought the salmon to Lester's door,
0:48:21 > 0:48:23will be frozen solid.
0:48:23 > 0:48:25Temperatures will drop to minus 50.
0:48:28 > 0:48:31But Lester isn't worried.
0:48:31 > 0:48:34There are advantages.
0:48:34 > 0:48:36I like winter.
0:48:38 > 0:48:41Cos I don't have to work so hard! HE LAUGHS
0:48:51 > 0:48:55All across Alaska, summer has delivered on its promise.
0:49:05 > 0:49:09Under the gaze of the sun, there's been plenty for everyone.
0:49:13 > 0:49:17Some have had to work harder than others.
0:49:17 > 0:49:20But most have managed to get their piece of the pie.
0:49:21 > 0:49:23Now time has run out.
0:49:27 > 0:49:31They say you're not a true Alaskan until you've faced a winter.
0:49:34 > 0:49:36It's time for the bold to step forward.
0:49:55 > 0:49:57Of all Alaska's animals,
0:49:57 > 0:50:00there was one that truly gave the film crew the run-around.
0:50:03 > 0:50:06Caribou.
0:50:06 > 0:50:10There are more than three quarters of a million of them,
0:50:10 > 0:50:12so they shouldn't be that hard to find.
0:50:15 > 0:50:17Filming them from the air is fairly easy.
0:50:17 > 0:50:20But keeping up with them on the ground while they're migrating
0:50:20 > 0:50:23is another matter.
0:50:25 > 0:50:28They can travel 50 miles in a single day.
0:50:28 > 0:50:30And this is rugged land.
0:50:33 > 0:50:37Cameraman Rob Drewett and producer Alex Lanchester
0:50:37 > 0:50:39were going to need some local knowledge
0:50:39 > 0:50:42if they were to stand any chance of tracking them down.
0:50:44 > 0:50:47Guide Dan Lee has spent most of his life in these hills
0:50:47 > 0:50:50looking for gold.
0:50:50 > 0:50:52He knows the wilderness pretty well.
0:50:54 > 0:50:57- See how round that is? Look at that.- Yeah.
0:50:58 > 0:51:01Real obvious caribou - big difference from moose.
0:51:03 > 0:51:06The team know they're in the right area.
0:51:06 > 0:51:08They're already spotting caribou.
0:51:12 > 0:51:15- (Where are they?) - (They're just right over the edge.)
0:51:18 > 0:51:22(We've just peeked over, there are ten or 15 just sitting there.
0:51:23 > 0:51:25(So good to see them.)
0:51:29 > 0:51:32But this is Alaska.
0:51:32 > 0:51:35You can never be sure what's going to turn up.
0:51:35 > 0:51:37And we've got a grizzly.
0:51:37 > 0:51:40- It's grubbing for roots up there. - Yeah, looks like it.
0:51:42 > 0:51:46It's quite weird me filming caribou which are that way
0:51:46 > 0:51:49and a grizzly bear that's just over my shoulder.
0:51:49 > 0:51:52Hope someone's keeping an eye on it.
0:51:53 > 0:51:57- Alex.- Er... - THEY LAUGH
0:51:57 > 0:52:02With a grizzly bear in the area, the caribou aren't hanging around.
0:52:02 > 0:52:05They're probably going that way, but we could go back around the trail.
0:52:05 > 0:52:08If they're going over the ridge, we could meet them,
0:52:08 > 0:52:10- cos there's another trail that goes that way.- OK.
0:52:10 > 0:52:13The caribou can go wherever they please.
0:52:13 > 0:52:16The team have to stick to the trails.
0:52:16 > 0:52:18It's starting to get challenging.
0:52:30 > 0:52:34We've just had 200-300 standing right here.
0:52:34 > 0:52:36And we were over there.
0:52:36 > 0:52:40And it took us ten minutes to get here and suddenly they're gone.
0:52:40 > 0:52:43- You see them all on that ridge over there?- Yeah.
0:52:45 > 0:52:49It's a cat-and-mouse situation.
0:52:49 > 0:52:52The caribou certainly aren't going to wait.
0:52:52 > 0:52:54The team need to get ahead of them.
0:52:54 > 0:52:58But even an all-terrain vehicle has its limitations round here.
0:53:06 > 0:53:10Are your wheels straight? You are right on a mud bank.
0:53:15 > 0:53:18I've gone and got us stuck in the mud right at the edge of the river
0:53:18 > 0:53:21and we are proper stuck.
0:53:21 > 0:53:24Where are you going, Alex?
0:53:24 > 0:53:26As the team try to free the vehicles,
0:53:26 > 0:53:30the caribou get further and further away.
0:53:30 > 0:53:33For them, a river crossing like this would be no trouble at all.
0:53:44 > 0:53:45Thank you!
0:53:45 > 0:53:47For the team, it gets worse.
0:53:47 > 0:53:48Aw!
0:53:50 > 0:53:53So we finally got our ATV out of the river
0:53:53 > 0:53:58and we got out and there's a flat tyre.
0:54:00 > 0:54:02And the spare doesn't fit.
0:54:02 > 0:54:05- Wrong pattern, huh? - No, the pattern's fine.
0:54:05 > 0:54:09- The bolts are too big for it. - Oh, no!- See?- Yeah!
0:54:11 > 0:54:14In Alaska, road assistance comes from the sky.
0:54:14 > 0:54:17I can't quite believe it's come to this.
0:54:22 > 0:54:25Thank you very much, Mike. You've saved our bacon, so thank you.
0:54:25 > 0:54:28OK, no problem, but we're going to get out of here before it changes.
0:54:28 > 0:54:31- Yeah, of course.- Have fun! - Thank you.
0:54:31 > 0:54:34It doesn't take long to change the wheel.
0:54:34 > 0:54:35But bad weather is coming in.
0:54:35 > 0:54:38The team decide to set up camp.
0:54:38 > 0:54:41And all the while, the distance between the team and the caribou
0:54:41 > 0:54:44is growing bigger and bigger.
0:54:50 > 0:54:54The following day, the weather isn't any brighter.
0:54:54 > 0:54:56Rained quite a bit last night.
0:54:56 > 0:55:00So it's a little disconcerting.
0:55:00 > 0:55:0424 hours of summer rain have made the rivers into torrents.
0:55:05 > 0:55:07With all the rain we've had,
0:55:07 > 0:55:09the river is way too high for us to cross.
0:55:09 > 0:55:13It could be two to three days until we can cross it.
0:55:13 > 0:55:16And then we don't know whether the herd's going to still be there
0:55:16 > 0:55:18because they'll still be moving.
0:55:19 > 0:55:23Another day lost and the caribou would've put 50 miles
0:55:23 > 0:55:25between themselves and the team.
0:55:26 > 0:55:29Caribou have no body clock telling them when to stop,
0:55:29 > 0:55:33so keep walking through the night.
0:55:33 > 0:55:36But the team have a tip-off from another guide.
0:55:36 > 0:55:41They drive 100 miles east, putting their faith in guide Claude Bondy.
0:55:41 > 0:55:43He knows of an unusual lake
0:55:43 > 0:55:47where he thinks the caribou will gather in big numbers.
0:55:49 > 0:55:51It could be the crew's lucky break.
0:55:54 > 0:55:58But getting there means a four-hour hike across a boggy landscape.
0:56:02 > 0:56:04It would be an easy journey for a caribou,
0:56:04 > 0:56:08with its great feet and long legs, but much harder for the team.
0:56:08 > 0:56:11In fact, we have to zigzag our way through,
0:56:11 > 0:56:16cos we've got just brush in front of us.
0:56:16 > 0:56:17Doesn't make things easy.
0:56:21 > 0:56:25ALEX BREATHES HEAVILY
0:56:29 > 0:56:32But Claude's hunch has paid off.
0:56:34 > 0:56:36He knew the caribou would stop at this lake.
0:56:38 > 0:56:41They're not just here for water,
0:56:41 > 0:56:45they're here for precious minerals buried in the lake bed.
0:56:45 > 0:56:49I didn't think it was going to happen, so...
0:56:49 > 0:56:52It's nice to see such a big group
0:56:52 > 0:56:55and we're talking thousands, so, amazing.
0:56:55 > 0:56:57Just need to get a little bit closer.
0:57:04 > 0:57:07(Whilst we've been sitting here,
0:57:07 > 0:57:10(we've been completely surrounded by caribou.
0:57:10 > 0:57:16(And they came about 30 metres away, which was pretty cool.)
0:57:16 > 0:57:20Even the guide is astonished.
0:57:20 > 0:57:23(This is the most caribou I've ever seen at one time.
0:57:23 > 0:57:25(It's incredible.
0:57:25 > 0:57:27(And they're all just kind of cruising right to Rob,
0:57:27 > 0:57:31(he's got to be just going crazy right now.)
0:57:31 > 0:57:33This close to the herd,
0:57:33 > 0:57:36the team are not only able to film the big numbers,
0:57:36 > 0:57:39but also capture behaviour not seen before,
0:57:39 > 0:57:42as the caribou stir up the mineral salts in the water
0:57:42 > 0:57:44and drink the solution.
0:57:44 > 0:57:48We've had so many problems along the way with rain,
0:57:48 > 0:57:51not seeing caribou, then being too far away.
0:57:51 > 0:57:56So finally got the shots we needed, so it feels really good.
0:58:02 > 0:58:04Next time...
0:58:04 > 0:58:06winter has returned.
0:58:06 > 0:58:10Those that cannot face it must leave.
0:58:10 > 0:58:15For those that stay, the rewards can be huge.
0:58:15 > 0:58:18But they must overcome minus 50 degree temperatures
0:58:18 > 0:58:21to become masters of an ice world.
0:58:21 > 0:58:23For many, it's courage that gets them through.
0:58:26 > 0:58:30But for a few Alaskans, this is the time they have been waiting for.