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Our planet is a place of constant change.
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Each year, the seasons shift and life is transformed.
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But there are places where the changes are so epic in scale
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they can be seen from space.
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In this series,
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we reveal three of the most miraculous transformations.
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The islands of Svalbard - within a few weeks,
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frozen wastelands burst into life.
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The African Okavango -
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a desert transforms into a magical waterworld.
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And the mysterious forests of New England -
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erupting in a blaze of seasonal colour.
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Life finds the most ingenious and surprising ways to thrive...
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..in the world's fastest-changing landscapes.
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New England - home to the most colourful forest in America.
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Stretching across six states...
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..from Maine in the north to Connecticut in the south.
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Every year, millions of people flock here to witness
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one of the planet's greatest spectacles,
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known here as the fall...
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..when billions of trees explode into a riot of red, orange and gold.
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There's nowhere else on Earth quite like it.
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But despite this beauty, there's a battle raging.
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One that holds the secret to this magical forest's most
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flamboyant display.
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The story of the fall begins
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while winter still has a grip on the forest.
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17 billion trees, rich with maples and oaks,
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wait in suspended animation.
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Amongst them,
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many of New England's animals are hibernating from the cold.
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But America's tallest mammal remains at large.
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Moose survive by chewing on twigs.
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Their calves will be born in just two months...
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..and their survival will depend on the same
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chain of events that will fuel the forest's climax of colour.
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As the weather warms, water courses through every tree...
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..and it picks up sugar stored in the wood.
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This liquid energy is the life force of the entire forest.
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It's so rich with sugar that maple syrup is made from it.
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The spring sunshine warms the land...
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..and the sugar surges faster...
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..fuelling the growth of nutrient-rich buds.
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These tiny packages contain everything needed to build a leaf.
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But from this point on, each tree faces a battle.
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All across New England, twigs are coming to life.
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These creatures spend the winter disguised as twigs.
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Looper caterpillars.
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They awake with the warmth and immediately begin to seek out
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the freshest buds, on a hunt for sugar.
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Nearby, hundreds of baby tent caterpillars
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hatch from their winter eggs.
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Each smaller than a grain of rice. They join the feast.
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Swarming along the branches, a torrent of bud destruction.
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This is just the first wave in a battle that will escalate
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through the year.
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The buds race to open before they can be attacked.
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Gradually, the first flush of green spreads across the forest.
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But it will be a few weeks before the leaves are fully expanded...
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..and they will need a constant supply of sugary
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sap from under the bark.
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In some trees, that sap is also at risk.
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The warming spring weather attracts an animal with a serious
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sugar addiction.
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TAPPING
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All the way from Mexico,
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he's one of the first to come back after the trees wake.
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The yellow-bellied sapsucker.
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His beak hammers six times a second...
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..wounding the tree deeply...
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..and chiselling into the vessels carrying the precious sugar.
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His feathery tongue quickly laps up the weeping liquid.
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On this tree last year, he dug hundreds of holes,
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but now, all the wells are dry.
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It's not enough to deter a determined sapsucker.
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He can dig as many as 1,000 holes in a season.
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And on another tree, he's excavating a nest.
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If he finishes it and keeps his wells running sweetly,
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he could attract the attention of a female.
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But there's another bird that could scupper his plans.
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A ruby-throated hummingbird.
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He's followed the sapsucker all the way from Mexico.
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His wings beat 80 times a second,
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putting him on a calorific knife edge.
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The weeping sap is the best source of sugar currently available,
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and feeding at 15 sips a second, he can quickly drain a well dry.
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He's too fast for the sapsucker to chase off...
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..so the sapsucker opens more and more wells.
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Eventually, despite the interruption,
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he finishes off his nest, creating a deep hollow in the tree.
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Now, everything is prepared.
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Despite relentless attack from birds and insects,
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the warming weather keeps the trees pumping sap,
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and, as the day length increases, the leaves continue to inflate.
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As the leaves grow, they start to shade the forest floor.
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In anticipation, the plants down below wake from their stupor.
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The flowers must attract a pollinator before all
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the light is stolen.
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Now, hummingbirds can feed on their favourite source of sugar.
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Nectar.
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In turn helping to pollinate the flowers.
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A looper caterpillar feeds amongst the flowers, too.
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He's no longer hiding amongst the twigs.
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This master of disguise has a different trick up his sleeve.
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Swaying back and forth, he mimics a flower moving in the breeze.
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He sticks petals to his back so that he can feed unnoticed by predators.
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And there's a whole army of flower arrangers sporting the latest
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spring fashion!
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As the sun strengthens,
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the building sap finally forces the leaves to fully unfurl.
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As many as 200,000 leaves on every tree.
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Together, they grow enough foliage to blanket an area six times
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the size of New England.
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As the leaves expand,
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they produce one of nature's most powerful chemicals.
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Chlorophyll.
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This green pigment catches the sun's energy to power
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a reaction crucial to all life.
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Photosynthesis - creating sugar from sunshine.
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This sugar is essential for the tree to grow,
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but it's now in easy reach of New England's hungriest animals.
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A moose.
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Named by the Native Americans as moosu, "he who strips off",
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they are leaf-eating machines...
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..and can strip a branch clean in seconds...
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..but the trees can defend themselves.
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In response, they flood their leaves with a repulsive chemical
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called tannin.
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So moose must constantly roam to seek out fresh ones.
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But this female doesn't want to travel far.
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She has twins and they're just two weeks old.
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Until now, they've remained hidden in the shade of the forest.
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With the leaves now loaded with unpleasant tannins,
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she needs to find an alternative food source.
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She leads the twins away from the cover of the trees
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for the very first time.
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Out here, it's a big, new world.
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The mother must stay close.
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Another cow and her calf are already enjoying the coolness of the lake.
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Moose have the longest legs in North America,
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which allows her to reach something that other animals can't get to.
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It's what makes this lake irresistible.
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Water plants.
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Just what this mother needs to enrich her milk...
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..because they're packed with nutrients
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washed out of the leaf litter.
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The twins will increase in weight tenfold over the next few months.
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It's not just the females who need the nutrients.
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Big bulls are here to feed for a different reason.
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To grow their antlers, one of the fastest-growing animal organs.
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They keep a safe distance.
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Neither wants to damage his prized possessions.
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Because their racks are not just for fighting.
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Male moose concentrate on looking good...
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and attracting females.
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With females watching on, it's a chance to show off.
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A good try, but at this time of the year,
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this female's attention is still fully on her calves.
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It won't be until the fall that she will be
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back on the market for a mate.
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Late spring, the busiest time
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for the forest's most notorious tree-eater.
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Signs of his appetites surround almost every lake.
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The beaver, New England's most industrious animal.
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His lodge is his castle, built of sticks and hardened by mud.
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But his masterpiece is his dam.
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Over 50 metres long and built of thousands of logs and branches.
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For 20 years it has held back the water to create a moat -
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a defence against predators.
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But this security comes at a price.
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The dam needs constant maintenance.
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A leak.
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He's going to need supplies.
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To avoid being spotted by predators,
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beavers work under the cover of darkness.
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There iron-infused teeth make powerful tools with which they can
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fell a tree ten inches wide in just a couple of hours.
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SNAPPING
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Fixing a leak can take all night
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and into the morning.
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He stirs up mud, using this mortar to seal the cracks.
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But fix one leak... and another is sure to spread.
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A beaver's work is never done.
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All this work isn't just for his own security.
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MEWING
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In spring, a beaver's lodge is busy with the activity of baby
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beavers and their sounds as they call for milk.
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MEWING AND PURRING
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This is a crucial time to practise using their teeth before
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they too are unleashed onto the forest.
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PURRING
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The beavers of New England fell millions of trees every year.
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But surprisingly, it's this that makes them heroes of the forest.
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By removing softer trees,
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they create large open spaces where red maple saplings can take root.
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And they leave bigger hardwoods standing, like maples
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and oaks, with space to spread their branches.
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With more leaves to create sugar, trees can grow ten times faster,
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and their colours in the fall will be much brighter.
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Beavers have helped to create a forest rich with maples and oaks.
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But 400 years ago, something happened that was to rapidly
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speed up what the beavers had started.
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Clues to this event can be seen threading through the forest.
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Stone walls.
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240,000 miles of them.
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Enough to reach the moon.
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In 1620, British settlers landed on these shores.
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Attracted by tales of green and pleasant lands...
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..they had hoped to create a prosperous life.
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What they encountered was an ancient dark forest,
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creaking with giant trees.
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And haunting sounds they had never heard before.
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BIRDS SQUAWK
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The trees towered above them,
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far higher than any they had seen in Britain.
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The biggest of them all was the white pine,
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said to have reached as high as 200 feet.
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By royal decree, the King of England claimed every one with
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a diameter greater than 24 inches.
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They were shipped across the Atlantic for use as the masts
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of the Royal Navy.
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The rest were left for settlers.
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They felled trees to build homes, churches and mills.
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Many animals, like mountain lions
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and wolves, were wiped out as the wilderness was tamed.
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By 1850, almost all of New England's
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forest had been chopped down,
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and much of this was turned to farmland,
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surrounded by stone walls.
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But then everything changed
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as richer farmland and gold was discovered in the west...
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..and many of the settlers chased their fortunes elsewhere.
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Towns like Livermore disappeared as quickly as they had been formed.
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Slowly, the trees of New England grew around the ruins
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and reclaimed the land.
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This new forest was very different.
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By chopping down the old-growth trees,
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people had given fast-growing maples and oaks a chance to claim the land.
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They grew back in greater numbers than ever before,
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and today they dominate this forest.
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From now on, there would be nowhere else more colourful in the fall.
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Today those stone walls are highways
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for one of New England's busiest animals.
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The chipmunk.
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There can be as many as 15 living in every acre...
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because New England is a chipmunk paradise.
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The stone walls help them to get around the forest
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and keep an eye out for predators.
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And the new forest provides all the acorns and maple seeds
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a chipmunk can eat.
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Today the forest is treasured,
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and 80% of New England is covered in trees,
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ensuring the fall remains rich and colourful.
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Because vast areas are uninhabited,
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in many places the sky is dark with little light pollution.
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New England is further south than the UK.
257
00:28:57,920 --> 00:29:00,600
But it's dark enough that on special nights
258
00:29:00,600 --> 00:29:04,040
the distant northern lights can be seen shining.
259
00:29:27,600 --> 00:29:30,000
The growth of the new forest paved the way
260
00:29:30,000 --> 00:29:33,000
for wildlife to move back in,
261
00:29:33,000 --> 00:29:37,160
and animals that were once persecuted now thrive here.
262
00:29:39,240 --> 00:29:41,480
DISTANT ANIMAL CALL
263
00:29:55,760 --> 00:29:57,840
It's the beginning of summer.
264
00:29:57,840 --> 00:30:01,440
And with daytime temperatures now in the mid-20s,
265
00:30:01,440 --> 00:30:06,320
it's warm enough to draw out New England's most misunderstood animal.
266
00:30:07,640 --> 00:30:10,720
RATTLING
267
00:30:13,120 --> 00:30:15,280
A timber rattlesnake.
268
00:30:18,200 --> 00:30:21,400
A creature at home hiding amongst the trees.
269
00:30:31,080 --> 00:30:35,400
It was once so feared, a bounty was placed on its head.
270
00:30:39,000 --> 00:30:42,000
But the timber rattlesnake is making a comeback,
271
00:30:42,000 --> 00:30:45,240
with a few hundred now living in these forests.
272
00:30:54,120 --> 00:30:59,640
Using his tongue, a large male seeks the scent of a potential meal.
273
00:31:02,760 --> 00:31:06,360
He's detected a log heavy with the scent of rodents.
274
00:31:13,000 --> 00:31:16,080
Coiled like a spring, he waits.
275
00:31:20,720 --> 00:31:23,160
FAINT RUSTLING
276
00:31:27,240 --> 00:31:29,200
FAINT PATTERING
277
00:31:40,960 --> 00:31:43,760
Even one of the fastest hunters on the planet
278
00:31:43,760 --> 00:31:46,320
can sometimes be off target.
279
00:31:54,520 --> 00:31:56,240
But he's patient.
280
00:32:03,560 --> 00:32:07,720
15 hours later, he's still in position.
281
00:32:14,560 --> 00:32:17,480
FAINT RUSTLING
282
00:32:18,440 --> 00:32:20,640
PATTERING
283
00:32:26,160 --> 00:32:28,560
MOUSE SQUEAKS
284
00:32:28,560 --> 00:32:31,040
He instantly withdraws his fangs,
285
00:32:31,040 --> 00:32:33,040
eager not to damage them.
286
00:32:38,280 --> 00:32:41,520
It won't take long for the venom to kill.
287
00:32:46,680 --> 00:32:50,160
He follows the mouse's scent to claim his prize.
288
00:32:53,040 --> 00:32:56,920
This should satisfy his hunger for a few weeks.
289
00:33:06,320 --> 00:33:08,280
It's the height of summer,
290
00:33:08,280 --> 00:33:11,560
and the trees' leaves are working at maximum capacity
291
00:33:11,560 --> 00:33:14,360
to turn sunlight into sugar.
292
00:33:17,400 --> 00:33:20,880
This is when they face their greatest battle.
293
00:33:20,880 --> 00:33:23,320
CHOMPING
294
00:33:23,320 --> 00:33:26,280
Billions of bugs are on the attack.
295
00:33:29,360 --> 00:33:33,000
The trees do everything they can to resist the onslaught.
296
00:33:37,280 --> 00:33:40,720
They increase the concentration of repulsive tannins
297
00:33:40,720 --> 00:33:42,800
in the surface of their leaves.
298
00:33:49,480 --> 00:33:53,200
But even this isn't enough to stop one hungry insect.
299
00:33:56,040 --> 00:33:58,240
Only a few millimetres long,
300
00:33:58,240 --> 00:34:01,520
this leaf miner is tunnelling under the skin,
301
00:34:01,520 --> 00:34:03,800
where he can avoid the bitter tannins
302
00:34:03,800 --> 00:34:06,240
and get to the juicy, sweet bits.
303
00:34:12,000 --> 00:34:14,600
Under the safety of the leaf itself,
304
00:34:14,600 --> 00:34:17,520
he devours so much green chlorophyll
305
00:34:17,520 --> 00:34:21,600
that the leaf can no longer produce the sugar it needs to stay alive.
306
00:34:29,120 --> 00:34:32,800
In just two days, he leaves a trail of destruction,
307
00:34:32,800 --> 00:34:35,880
and his appetite shows no signs of slowing.
308
00:34:45,200 --> 00:34:48,520
Most insects are too big to squeeze inside a leaf,
309
00:34:48,520 --> 00:34:51,400
so they must be more selective in how they attack.
310
00:34:57,320 --> 00:34:59,960
Many eat carefully between the veins,
311
00:34:59,960 --> 00:35:03,760
avoiding areas with higher concentrations of tannins...
312
00:35:05,440 --> 00:35:08,600
..leaving the leaf skeletonised in their wake.
313
00:35:19,760 --> 00:35:21,720
The bigger caterpillars get,
314
00:35:21,720 --> 00:35:25,320
the more they can process the leaves' unpleasant chemicals.
315
00:35:28,720 --> 00:35:33,120
And working en masse, caterpillars can devour a leaf in minutes.
316
00:35:35,920 --> 00:35:39,000
But they themselves could easily fall prey to birds.
317
00:35:40,360 --> 00:35:43,960
So disguise is the key to their success.
318
00:35:48,640 --> 00:35:53,080
Some mimic dangerous New England animals to deter their predators.
319
00:35:54,640 --> 00:35:58,560
Swallowtails have eye spots to look like snakes.
320
00:36:01,160 --> 00:36:05,360
The hag moth caterpillar resembles a big spider.
321
00:36:08,520 --> 00:36:11,080
And the fur of this one makes it tricky
322
00:36:11,080 --> 00:36:13,400
for a predator to get to the soft bits.
323
00:36:17,240 --> 00:36:19,920
But the most cunning disguise of all
324
00:36:19,920 --> 00:36:23,880
is to mimic the parts of the leaf that they've already eaten.
325
00:36:27,600 --> 00:36:32,960
Many New England caterpillars look like nothing more than leaf damage.
326
00:36:35,680 --> 00:36:37,760
Filling in the gaps with their bodies
327
00:36:37,760 --> 00:36:40,320
makes them less visible to birds.
328
00:36:43,600 --> 00:36:47,640
New England is swarming with undercover caterpillars.
329
00:36:49,920 --> 00:36:53,600
But there's one predator that caterpillars can't hide from.
330
00:36:55,360 --> 00:36:59,520
Because here the trees have an ally.
331
00:36:59,520 --> 00:37:02,240
An army is being mobilised.
332
00:37:06,280 --> 00:37:09,520
These are the Allegheny mound ants,
333
00:37:09,520 --> 00:37:12,600
and the trees are their hunting grounds.
334
00:37:23,280 --> 00:37:27,200
Like lions in the leaf litter, they hunt in a pack...
335
00:37:30,680 --> 00:37:32,960
..efficiently trimming the hairs
336
00:37:32,960 --> 00:37:35,200
so they can get to the sugary juices...
337
00:37:36,680 --> 00:37:39,000
..draining the caterpillar dry.
338
00:37:42,280 --> 00:37:44,960
But this isn't food for THEM to eat.
339
00:37:48,560 --> 00:37:51,200
In the warm interiors of their mounds,
340
00:37:51,200 --> 00:37:54,800
the summer heat is incubating the next generation.
341
00:37:58,760 --> 00:38:03,200
Caterpillar juice is the perfect nourishment for a growing soldier,
342
00:38:03,200 --> 00:38:07,920
supercharged with sugar that the caterpillars stole from the leaves.
343
00:38:13,400 --> 00:38:16,480
Soon they will be ready to help the colony expand.
344
00:38:25,800 --> 00:38:29,200
Every year ants dig miles of tunnels
345
00:38:29,200 --> 00:38:32,720
and excavate as much as 12 tonnes in every acre.
346
00:38:44,240 --> 00:38:47,280
This aerates and breaks down the leaf litter,
347
00:38:47,280 --> 00:38:49,640
which fertilises the soil.
348
00:38:57,560 --> 00:39:00,240
Trees with rich soil and ant protection
349
00:39:00,240 --> 00:39:02,160
produce more sugar,
350
00:39:02,160 --> 00:39:03,560
they're brighter,
351
00:39:03,560 --> 00:39:07,680
and they will hang on to their leaves for longer during the fall.
352
00:39:16,440 --> 00:39:19,360
Despite the battles raging through the forest,
353
00:39:19,360 --> 00:39:22,560
billions of leaves continue to produce sugar.
354
00:39:30,080 --> 00:39:32,800
This is transported down the trunk,
355
00:39:32,800 --> 00:39:37,080
where it's stored to replace the tree's reserves.
356
00:39:37,080 --> 00:39:42,520
Each will gain as much as 100kg in weight before the end of the year.
357
00:39:49,320 --> 00:39:51,080
FAINT TAPPING
358
00:39:51,080 --> 00:39:54,040
BIRD CALLS
359
00:39:54,040 --> 00:39:57,600
The yellow-bellied sapsucker has attracted a female,
360
00:39:57,600 --> 00:40:01,680
and in their nest they have four young chicks just a few days old.
361
00:40:01,680 --> 00:40:03,840
CHICKS CHEEP
362
00:40:12,120 --> 00:40:15,400
Their parents bring back food 20 times every hour.
363
00:40:18,040 --> 00:40:19,960
BIRD CALLS
364
00:40:22,080 --> 00:40:24,840
It's exhausting, keeping up with the demand.
365
00:40:28,200 --> 00:40:29,640
CHICK CHEEPS
366
00:40:29,640 --> 00:40:31,280
The summer sap is sweeter,
367
00:40:31,280 --> 00:40:34,040
and it attracts a swarm of insects.
368
00:40:40,720 --> 00:40:45,000
This is why the father has been obsessively digging wells -
369
00:40:45,000 --> 00:40:48,880
because the sap leaking from them is now bait.
370
00:40:54,720 --> 00:40:57,640
And not even the trees' allies, the ants,
371
00:40:57,640 --> 00:41:00,560
can resist a nibble of the free-flowing sugar.
372
00:41:02,280 --> 00:41:03,480
CHICK CHEEPS
373
00:41:03,480 --> 00:41:06,360
For the chicks to grow, they need protein.
374
00:41:09,040 --> 00:41:13,240
Sugar-coated bugs make up two-thirds of their summer diet.
375
00:41:18,920 --> 00:41:22,200
Because of the constant supply of insects,
376
00:41:22,200 --> 00:41:25,080
the chicks increase in weight by 16 times
377
00:41:25,080 --> 00:41:26,720
in just four weeks.
378
00:41:30,600 --> 00:41:32,560
CHICKS CHEEP
379
00:41:36,000 --> 00:41:40,360
And they're already learning the art of tapping for themselves.
380
00:41:40,360 --> 00:41:42,640
CHICKS CHEEP
381
00:41:44,320 --> 00:41:46,040
In three months' time,
382
00:41:46,040 --> 00:41:49,600
they will depart the cooling forest for warmer climates in the south.
383
00:41:51,480 --> 00:41:53,600
This will give the trees a chance
384
00:41:53,600 --> 00:41:57,120
to repair the damage before the summer ends.
385
00:42:11,600 --> 00:42:16,400
This female rattlesnake has spent three months basking in the sun,
386
00:42:16,400 --> 00:42:18,280
but daytime temperatures
387
00:42:18,280 --> 00:42:23,640
are now dropping as low as 14 degrees Celsius.
388
00:42:23,640 --> 00:42:26,920
Being cold-blooded, she is the first in the forest
389
00:42:26,920 --> 00:42:30,200
to feel a chill in the air as the days draw in.
390
00:42:33,480 --> 00:42:36,000
She's getting too big for her skin,
391
00:42:36,000 --> 00:42:40,080
but yawning widely helps to loosen it.
392
00:42:49,320 --> 00:42:53,640
And snags in the leaf litter help her to undress,
393
00:42:53,640 --> 00:42:55,960
peeling away the scaly layer.
394
00:43:09,440 --> 00:43:12,800
This lethal hunter is now ready.
395
00:43:28,280 --> 00:43:32,600
In a safe and secure place, specially adapted for filming,
396
00:43:32,600 --> 00:43:34,560
she waits.
397
00:43:50,840 --> 00:43:54,560
Through the night, months of preparation comes to an end.
398
00:43:59,080 --> 00:44:03,000
She's given birth to seven tiny rattlesnakes.
399
00:44:06,600 --> 00:44:09,200
Only 20 centimetres long,
400
00:44:09,200 --> 00:44:11,360
and already their sharp fangs
401
00:44:11,360 --> 00:44:13,960
are fully loaded with potent venom.
402
00:44:17,560 --> 00:44:19,560
Unlike most other snakes,
403
00:44:19,560 --> 00:44:20,920
timber rattlesnakes
404
00:44:20,920 --> 00:44:24,640
carry their babies inside their bodies to keep them warm.
405
00:44:26,360 --> 00:44:28,360
And there's one more on the way.
406
00:45:06,840 --> 00:45:11,520
The mother's work doesn't end there. Her maternal bond is strong.
407
00:45:15,560 --> 00:45:18,480
Having the fiercest mother in the forest,
408
00:45:18,480 --> 00:45:21,880
there's very little that could threaten these baby snakes.
409
00:45:26,160 --> 00:45:30,640
One by one, they snuggle into the safety of her coils.
410
00:45:40,080 --> 00:45:43,200
It won't be long until the cooling fall weather
411
00:45:43,200 --> 00:45:46,520
forces New England's rattlesnakes to lead their babies
412
00:45:46,520 --> 00:45:48,320
to underground dens,
413
00:45:48,320 --> 00:45:51,840
where they will hibernate as families until the spring.
414
00:46:04,160 --> 00:46:06,480
The shortening days and cooling weather
415
00:46:06,480 --> 00:46:10,800
trigger a change in the behaviour of New England's biggest animal.
416
00:46:14,960 --> 00:46:18,280
Male moose have been growing their antlers all year,
417
00:46:18,280 --> 00:46:20,960
and now they're dressed to impress.
418
00:46:26,360 --> 00:46:29,160
And finally, the females are open to their advances.
419
00:46:29,160 --> 00:46:31,000
FAINT BELLOW
420
00:46:33,000 --> 00:46:35,960
But some moose have more luck than others.
421
00:46:39,320 --> 00:46:40,880
SPLASHING
422
00:46:42,600 --> 00:46:46,600
This younger male has been following a female for weeks
423
00:46:46,600 --> 00:46:48,760
in the hope of getting her attention.
424
00:46:51,920 --> 00:46:53,320
It's tiring work,
425
00:46:53,320 --> 00:46:55,520
and to make matters worse,
426
00:46:55,520 --> 00:46:57,680
she's still caring for a calf.
427
00:47:05,400 --> 00:47:09,640
But with antlers like this, how could she possibly resist?
428
00:47:14,160 --> 00:47:17,920
He decides to make a bolder move before a bigger bull shows up.
429
00:47:19,400 --> 00:47:21,720
MOOSE SMACKS LIPS
430
00:47:21,720 --> 00:47:25,360
Lip-smacking makes his intentions clear.
431
00:47:32,400 --> 00:47:34,960
Her scent is irresistible.
432
00:47:44,880 --> 00:47:47,400
Not the response he was hoping for.
433
00:47:50,800 --> 00:47:54,600
Urination gives him a sign that she's still not in the mood.
434
00:47:57,160 --> 00:48:00,680
Even after weeks of trying to court her,
435
00:48:00,680 --> 00:48:03,280
persistence doesn't always pay off.
436
00:48:06,040 --> 00:48:08,040
THUNDER RUMBLES
437
00:48:08,040 --> 00:48:12,280
Fortunately, every year, thanks to the nutrition from the forest,
438
00:48:12,280 --> 00:48:14,280
a moose grows a bigger rack.
439
00:48:16,200 --> 00:48:17,680
THUNDER RUMBLES
440
00:48:17,680 --> 00:48:19,080
And next time,
441
00:48:19,080 --> 00:48:23,320
maybe his antlers will be big enough to impress the choosy female.
442
00:48:37,080 --> 00:48:40,240
With the temperature now constantly below ten degrees,
443
00:48:40,240 --> 00:48:43,480
the leaves can no longer work efficiently.
444
00:48:43,480 --> 00:48:46,440
And with less than 12 hours of sunshine a day,
445
00:48:46,440 --> 00:48:49,680
they have less time to create sugar for the trees.
446
00:48:51,600 --> 00:48:55,520
There comes a point when they are no longer earning their keep,
447
00:48:55,520 --> 00:48:58,720
and the tree must start to close down for the winter.
448
00:49:05,600 --> 00:49:08,640
At first, the effects are subtle.
449
00:49:08,640 --> 00:49:11,320
Individual leaves start to turn yellow.
450
00:49:15,920 --> 00:49:18,400
Like tiny factories closing down,
451
00:49:18,400 --> 00:49:22,120
the green pigment inside each cell is dismantled.
452
00:49:26,400 --> 00:49:28,840
The tree salvages all that it can,
453
00:49:28,840 --> 00:49:32,560
carrying it down in the sap to be stored in the tree's trunk.
454
00:49:34,680 --> 00:49:37,560
The cooling weather quickens the process,
455
00:49:37,560 --> 00:49:42,560
until the Midas touch of fall turns entire forests golden.
456
00:49:56,880 --> 00:49:59,160
But this is only just the beginning
457
00:49:59,160 --> 00:50:01,640
of the most magical transformation of all.
458
00:50:03,160 --> 00:50:05,440
The fall in New England.
459
00:50:08,720 --> 00:50:11,960
While most trees are already preparing for the winter...
460
00:50:13,520 --> 00:50:18,440
..some also take this opportunity to secure a future for their offspring.
461
00:50:22,920 --> 00:50:26,880
They drop millions of winged maple seeds and acorns.
462
00:50:36,960 --> 00:50:40,640
Many will soon be safely hidden beneath leaf fall
463
00:50:40,640 --> 00:50:43,600
to await the nourishing warmth of spring.
464
00:50:49,120 --> 00:50:51,200
But they've been spotted.
465
00:50:51,200 --> 00:50:54,040
Despite the cover, there's one animal
466
00:50:54,040 --> 00:50:57,760
who is able to sniff out a fresh nut amongst the leaf litter.
467
00:50:59,160 --> 00:51:00,640
A chipmunk.
468
00:51:03,720 --> 00:51:08,080
His small size means that he's unable to pile on enough body fat
469
00:51:08,080 --> 00:51:11,000
to survive hibernation through the winter.
470
00:51:13,320 --> 00:51:16,480
And just when reserves are looking a little thin...
471
00:51:17,520 --> 00:51:20,280
..a new air drop is delivered by the trees.
472
00:51:25,280 --> 00:51:26,760
Perfect timing...
473
00:51:27,840 --> 00:51:31,080
..if he can stockpile enough in his secret caches.
474
00:51:38,200 --> 00:51:41,680
He can squeeze four acorns into his cheek pouches,
475
00:51:41,680 --> 00:51:44,800
allowing him to collect up to 160 a day.
476
00:51:49,640 --> 00:51:52,680
It takes a lot of work to amass a big stash.
477
00:51:54,040 --> 00:51:57,600
But there's always one who's less prepared to put in the hours.
478
00:52:01,320 --> 00:52:03,200
A lazy chipmunk.
479
00:52:04,440 --> 00:52:08,000
He's spotted his neighbour's acorn and where it's being hidden.
480
00:52:10,440 --> 00:52:12,400
It's too tempting.
481
00:52:16,680 --> 00:52:19,240
But it's not an easy steal.
482
00:52:19,240 --> 00:52:21,800
SQUEAKING
483
00:52:38,640 --> 00:52:42,160
This is one chipmunk determined to protect his stash.
484
00:52:45,480 --> 00:52:48,360
The chipmunk is a hero of the forest -
485
00:52:48,360 --> 00:52:50,840
because even after all that work,
486
00:52:50,840 --> 00:52:54,360
he will forget where he's buried some of his hard-earned treasure.
487
00:52:56,840 --> 00:53:00,800
And protected underground, the seeds have a better chance of germinating.
488
00:53:04,400 --> 00:53:06,920
Whether they are a tree's enemy or an ally,
489
00:53:06,920 --> 00:53:09,640
the animals of New England have conspired
490
00:53:09,640 --> 00:53:12,760
to make the fall a season of beauty.
491
00:53:12,760 --> 00:53:14,120
And one thing is for sure -
492
00:53:14,120 --> 00:53:17,880
in the end, it's the entire forest that wins.
493
00:53:19,840 --> 00:53:23,720
And as the trees make their final preparations for winter,
494
00:53:23,720 --> 00:53:25,520
the best is yet to come.
495
00:53:35,080 --> 00:53:38,080
As the temperature drops towards freezing,
496
00:53:38,080 --> 00:53:39,920
the trees increase the speed
497
00:53:39,920 --> 00:53:42,720
at which they drain the leaves of their goodness.
498
00:53:44,000 --> 00:53:46,440
A magical new chemical is conjured up
499
00:53:46,440 --> 00:53:49,920
from within the leaves of the maple and oak trees.
500
00:53:52,320 --> 00:53:54,280
Red anthocyanin.
501
00:53:57,560 --> 00:54:01,720
It keeps the sap flowing for longer as the temperature plummets,
502
00:54:01,720 --> 00:54:04,360
so the trees can hold on to their leaves
503
00:54:04,360 --> 00:54:07,560
and extract every last drop of sugar.
504
00:54:13,280 --> 00:54:16,000
The reds and oranges join the golds,
505
00:54:16,000 --> 00:54:19,560
and together they set the forest ablaze.
506
00:54:23,440 --> 00:54:27,960
From an ocean of green, every tree becomes an individual.
507
00:54:33,840 --> 00:54:37,200
Red maples and oaks burn in shades of red.
508
00:54:47,720 --> 00:54:50,200
Sugar maples glimmer in orange.
509
00:54:53,560 --> 00:54:55,880
And for just a few weeks every year...
510
00:54:56,920 --> 00:54:59,920
..New England is a wonderland of colour.
511
00:55:22,400 --> 00:55:25,360
These colours can be seen from space,
512
00:55:25,360 --> 00:55:29,440
spreading across this corner of America like wildfire.
513
00:55:33,520 --> 00:55:36,480
The spectacle is intense, but brief.
514
00:55:38,800 --> 00:55:42,400
As the last of the nutrients and sugars are extracted by the trees,
515
00:55:42,400 --> 00:55:45,600
billions of leaves hang on tenterhooks.
516
00:55:48,040 --> 00:55:50,960
All it takes...is a breeze.
517
00:56:02,000 --> 00:56:05,640
It's the last chance for their most persistent enemy to feast.
518
00:56:05,640 --> 00:56:07,560
CHOMPING
519
00:56:14,760 --> 00:56:18,480
Caterpillars... in a hungry race against time.
520
00:56:29,960 --> 00:56:34,000
Leaf miners are still feeding as the leaf changes around them.
521
00:56:35,040 --> 00:56:38,320
They eat all that they can before a quick getaway.
522
00:56:41,720 --> 00:56:45,000
Some caterpillars chase the colour through the fall.
523
00:56:47,280 --> 00:56:51,400
The spicebush swallowtail swaps the green costume of summer
524
00:56:51,400 --> 00:56:53,200
for a golden coat.
525
00:56:58,280 --> 00:57:00,400
And, having had her fill,
526
00:57:00,400 --> 00:57:04,760
she sheds this new skin to form an overwintering pupa that,
527
00:57:04,760 --> 00:57:07,160
like a leaf, fades to brown.
528
00:57:15,760 --> 00:57:19,560
Many other caterpillars turn red and orange in the fall.
529
00:57:20,680 --> 00:57:24,040
And as the leaves lose the last of their sugar,
530
00:57:24,040 --> 00:57:26,920
they climb to the edge of a leaf...
531
00:57:26,920 --> 00:57:29,200
and take a leap of faith.
532
00:57:36,920 --> 00:57:40,920
Amongst the leaf litter they seek out a refuge from the winter.
533
00:57:43,080 --> 00:57:45,800
In the spring, they will emerge as moths
534
00:57:45,800 --> 00:57:49,520
and unleash a new generation of caterpillars onto the forest.
535
00:57:56,720 --> 00:57:58,800
It's the end of October,
536
00:57:58,800 --> 00:58:02,080
and the planet's most colourful forest fades
537
00:58:02,080 --> 00:58:04,360
as the last leaves fall.
538
00:58:04,360 --> 00:58:08,200
They have given the trees all that they need to survive...
539
00:58:12,520 --> 00:58:15,840
..until the battles begin again next year.
44028
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