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Earth's Greatest Spectacles

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🐳
Animals
Transcript
00:03our planet is a place of constant change each year the seasons shift and life is transformed
00:13but there are places where the changes are so epic in scale they can be seen from space
00:21in this series we reveal three of the most miraculous transformations
00:28the islands of svalbard within a few weeks frozen wastelands burst into life
00:37the african okavango a desert transforms into a magical water world
00:45and the mysterious forests of new england erupting in a blaze of seasonal color
00:54life finds the most ingenious and surprising ways to thrive
01:00in the world's fastest changing landscapes
01:16new england home to the most colorful forest in america stretching across six states
01:28from maine in the north to connecticut in the south
01:35every year millions of people flock here to witness one of the planet's greatest spectacles
01:42known here as the fall
01:46and billions of trees explode into a riot of red orange and gold
01:56there's nowhere else on earth quite like it
02:02but despite this beauty there's a battle raging
02:09one that holds the secret to this magical forest's most flamboyant display
02:41the story of the fall begins while winter still has a
02:45grip on the forest
02:50seventeen billion trees rich with maples and oaks wait in suspended animation
02:59amongst them many of new england's animals are hibernating from the cold
03:08but america's tallest mammal remains at large
03:18moose survive by chewing on twigs
03:28their calves will be born in just two months and their survival will depend on the same chain of events
03:36plants that will fuel the forest's climax of color
03:44as the weather warms water courses through every tree
03:51and it picks up sugar stored in the wood
03:56this liquid energy is the life force of the entire forest
04:03it's so rich with sugar that maple syrup is made from it
04:12the spring sunshine warms the land
04:18and the sugar surges faster
04:22fueling the growth of nutrient-rich buds
04:33these tiny packages contain everything needed to build a leaf
04:43but from this point on each tree faces a battle
04:55of the new england
04:56all across new england twigs are coming to life
05:09these creatures spend the winter disguised as twigs
05:17looper caterpillars
05:25they awake with the warmth
05:28they awake with the warmth
05:28and immediately begin to seek out the freshest buds
05:32on a hunt for sugar
05:39nearby hundreds of baby tent caterpillars hatch from their winter eggs
05:49each smaller than a grain of rice
05:52they join the feast
05:59swarming along the branches
06:01a torrent of bud destruction
06:08this is just the first wave in a battle that will escalate through the year
06:17the buds race to open before they can be attacked
06:25gradually the first flush of green spreads across the forest
06:33but it will be a few weeks before the leaves are fully expanded
06:40and they will need a constant supply of sugary sap from under the bark
06:46in some trees that sap is also at risk
06:55the warming spring weather attracts an animal with a serious sugar addiction
07:07all the way from mexico
07:10he's one of the first to come back after the trees wake
07:19the yellow-bellied sapsucker
07:25his beak hammers six times a second
07:31wounding the tree deeply
07:32and chiseling into the vessels carrying the precious sugar
07:46his feathery tongue quickly laps up the weeping liquid
07:59on this tree last year he dug hundreds of holes
08:03but now all the wells are dry
08:11it's not enough to deter a determined sapsucker
08:15he can dig as many as one thousand holes in a season
08:25and on another tree
08:27he's excavating a nest
08:31if he finishes it and keeps his wells running sweetly
08:35he could attract the attention of a female
08:41but there's another bird that could scupper his plans
08:45a ruby-throated hummingbird
08:52he's followed the sapsucker all the way from mexico
09:05his wings beat 80 times a second putting him on a calorific knife edge
09:19the weeping sap is the best source of sugar currently available
09:23and feeding at 15 sips a second he can quickly drain a well dry
09:31he's too fast for the sapsucker to chase off
09:39so the sapsucker opens more and more wells
09:57eventually despite the interruption he finishes off his nest
10:02creating a deep hollow in the tree
10:06now everything is prepared
10:20despite relentless attack from birds and insects
10:23the warming weather keeps the trees pumping sap
10:27and as the day length increases the leaves continue to inflate
10:37as the leaves grow they start to shade the forest floor
10:45in anticipation the plants down below wake from their stupor
11:03the flowers must attract a pollinator before all the light is stolen
11:11now hummingbirds can feed on their favorite source of sugar nectar
11:20in turn helping to pollinate the flowers
11:38a looper caterpillar feeds amongst the flowers too
11:43he's no longer hiding amongst the twigs
11:46this master of disguise has a different trick up his sleeve
11:55swaying back and forth he mimics a flower moving in the breeze
12:03he sticks petals to his back so that he can feed unnoticed by predators
12:14and there's a whole army of flower arrangers sporting the latest spring fashion
12:27as the sun strengthens the building sap finally forces the leaves to fully unfurl
12:43as many as 200 000 leaves on every tree
12:55together they grow enough foliage to blanket an area six times the size of new england
13:07as the leaves expand they produce one of nature's most powerful chemicals
13:16chlorophyll this green pigment catches the sun's energy to power a reaction crucial to all life
13:27photosynthesis creating sugar from sunshine
13:37this sugar is essential for the tree to grow but it's now in easy reach of new england's hungriest animals
13:56a moose
14:03named by the native americans as moosu he who strips off they are leaf eating machines
14:12and can strip a branch clean in seconds
14:19but the trees can defend themselves
14:24in response they flood their leaves with a repulsive chemical called tannin
14:31so moose must constantly roam to seek out fresh ones
14:37but this female doesn't want to travel far
14:43she has twins and they're just two weeks old
14:49until now they've remained hidden in the shade of the forest
14:54with the leaves now loaded with unpleasant tannins she needs to find an alternative food source
15:12she leads the twins away from the cover of the trees for the very first time
15:23she leads the twins away from the tree of the tree of the tree of the tree of the tree
15:34out here it's a big new world
15:42the mother must stay close
15:51another cow and her calf are already enjoying the coolness of the lake
16:00moose have the longest legs in north america
16:03which allows her to reach something that other animals can't get to
16:08it's what makes this lake irresistible
16:16water plants
16:20just what this mother needs to enrich her milk
16:29because they're packed with nutrients
16:32washed out of the leaf litter
17:01the twins will increase in weight tenfold over the next few months
17:11it's not just the females who need the nutrients
17:19big bulls are here to feed for a different reason
17:25to grow their antlers one of the fastest growing animal organs
17:44they keep a safe distance
17:47neither wants to damage his prized possessions
17:51because their racks are not just for fighting
17:56male moose concentrate on looking good
18:00and attracting females
18:05female moose concentrate on looking good
18:06with females watching on
18:07it's a chance to show off
18:20a good try
18:22but at this time of year this female's attention is still fully on her calves
18:32it won't be until the fall that she will be back on the market for a mate
18:57late spring
18:58the busiest time for the forest's most notorious tree eater
19:11the beaver
19:12signs of his appetite surround almost every lake
19:24the beaver
19:26new england's most industrious animal
19:32his lodge is his castle built of sticks and hardened by mud
19:39but his masterpiece is his dam
19:43over fifty meters long and built of thousands of logs and branches
19:49for twenty years it has held back the water to create a moat
19:54a defense against predators
19:58but this security comes at a price
20:03the dam needs constant maintenance
20:08a leak
20:10he's going to need supplies
20:18to avoid being spotted by predators
20:21beavers work under the cover of darkness
20:37their iron infused teeth make powerful tools with which they can fell a tree
20:42be 10 inches wide in just a couple of hours
21:01fixing a leak can take all night
21:05and into the morning
21:27he stirs up mud
21:30using this mortar to seal the cracks
21:37but fix one leak
21:39and another is sure to sprout
21:47a beaver's work is never done
21:57all this work isn't just for his own security
22:06in spring
22:07in spring a beaver's lodge is busy with the activity of baby beavers
22:12and their sounds as they call for milk
22:36this is a crucial time to practice using their teeth
22:40before they too are unleashed onto the forest
22:53the beavers of new england fell millions of trees every year
22:58but surprisingly it's this that makes them heroes of the forest
23:07by removing softer trees they create large open spaces where red maple saplings can take root
23:15and they leave bigger hardwoods standing
23:19like maples and oaks
23:21with space to spread their branches
23:31with more leaves to create sugar
23:33with more leaves to create sugar
23:35trees can grow 10 times faster
23:36and their colors in the fall
23:39and their colors in the fall will be much brighter
23:45beavers have helped to create a forest rich with maples and oaks
23:51but 400 years ago something happened that was to rapidly speed up what the beavers had started
24:04clues to this event can be seen threading through the forest
24:10stone walls
24:14240 000 miles of them enough to reach the moon
24:24in 1620 british settlers landed on these shores
24:29attracted by tales of green and pleasant lands
24:34they had hoped to create a prosperous life
24:43what they encountered was an ancient dark forest creaking with giant trees
24:54and haunting sounds they had never heard before
25:02the trees towered above them far higher than any they had seen in britain
25:10the biggest of them all was the white pine
25:14said to have reached as high as 200 feet
25:22by royal decree the king of england claimed every one with a diameter greater than 24 inches
25:29they were shipped across the atlantic for use as the masts of the royal navy
25:45they felled trees to build homes churches and mills
25:56trees to build homes and trees to build homes and animals like mountain lions and wolves
25:59were wiped out as the wilderness was tamed
26:05by 1850 almost all of new england's forest had been chopped down and much of this was turned to farmland
26:14surrounded by stone walls
26:19but then everything changed as richer farmland and gold was discovered in the west
26:27and many of the settlers chased their fortunes elsewhere
26:36towns like livermore disappeared as quickly as they had been formed
26:44slowly the trees of new england grew around the ruins and reclaimed the land
26:56this new forest was very different
26:59by chopping down the old growth trees
27:02people had given fast growing maples and oaks a chance to claim the land
27:09they grew back in greater numbers than ever before
27:13and today they dominate this forest
27:20from now on there would be nowhere else more colorful in the fall
27:27today those stone walls are highways for one of new england's busiest animals
27:38the chipmunk
27:45there can be as many as 15 living in every acre
27:49because new england is a chipmunk paradise
27:57the stone walls help them to get around the forest and keep an eye out for predators
28:06and the new forest provides all the acorns and maple seeds a chipmunk can eat
28:24today the forest is treasured and 80 percent of new england is covered in trees
28:30ensuring the fall remains rich and colorful
28:43Because vast areas are uninhabited, in many places the sky is dark with little light pollution.
28:52New England is further south than the UK, but it's dark enough that on special nights the distant northern lights
29:01can be seen shining.
29:26The growth of the new forest paved the way for wildlife to move back in, and animals that were once
29:33persecuted
29:34now thrive here.
29:54It's the beginning of summer, and with daytime temperatures now in the mid-twenties, it's warm enough to draw out
30:02New England's most misunderstood animal.
30:11A timber rattlesnake.
30:16A creature at home hiding amongst the trees.
30:29It was once so feared, a bounty was placed on its head.
30:37But the timber rattlesnake is making a comeback, with a few hundred now living in these forests.
30:52Using his tongue, a large male seeks the scent of a potential meal.
31:01He's detected a log heavy with the scent of rodents.
31:11Coiled like a spring, he waits.
31:39Even one of the fastest hunters on the planet can sometimes be off target.
31:53But he's patient.
32:0215 hours later, he's still in position.
32:27He instantly withdraws his fangs, eager not to damage them.
32:36It won't take long for the venom to kill.
32:45He follows the mouse's scent to claim his prize.
32:51This should satisfy his hunger for a few weeks.
33:04It's the height of summer, and the tree's leaves are working at maximum capacity to turn sunlight into sugar.
33:16This is when they face their greatest battle.
33:22Billions of bugs are on the attack.
33:28The trees do everything they can to resist the onslaught.
33:35They increase the concentration of repulsive tannins in the surface of their leaves.
33:48But even this isn't enough to stop one hungry insect.
33:54Only a few millimetres long, this leaf miner is tunnelling under the skin, where he can avoid the bitter tannins
34:02and get to the juicy sweet bits.
34:10Under the safety of the leaf itself, he devours so much green chlorophyll that the leaf can no longer produce
34:18the sugar it needs to stay alive.
34:28In just two days he leaves a trail of destruction, and his appetite shows no signs of slowing.
34:44Most insects are too big to squeeze inside a leaf, so they must be more selective in how they attack.
34:56Many eat carefully between the veins, avoiding areas with higher concentrations of tannins, leaving the leaf skeletonized in their wake.
35:18The bigger caterpillars get, the more they can process the leaves' unpleasant chemicals.
35:27And working en masse, caterpillars can devour a leaf in minutes.
35:34But they themselves could easily fall prey to birds.
35:38So, disguise is the key to their success.
35:47Some mimic dangerous New England animals to deter their predators.
35:53Swallowtails have eye spots to look like snakes.
35:59The hag moth caterpillar resembles a big spider.
36:07And the fur of this one makes it tricky for a predator to get to the soft bits.
36:16But the most cunning disguise of all is to mimic the parts of the leaf that they've already eaten.
36:26Many New England caterpillars look like nothing more than leaf damage.
36:34Filling in the gaps with their bodies makes them less visible to birds.
36:42New England is swarming with undercover caterpillars.
36:48But there's one predator that caterpillars can't hide from.
36:54Because here, the trees have an ally.
36:58An army is being mobilized.
37:05These are the Allegheny mound ants.
37:08And the trees are their hunting grounds.
37:21Like lions in the leaf litter, they hunt in a pack.
37:30Efficiently trimming the hairs so they can get to the sugary juices.
37:35Draining the caterpillar dry.
37:41But this isn't food for them to eat.
37:47In the warm interiors of their mounds, the summer heat is incubating the next generation.
37:57Caterpillar juice is the perfect nourishment for a growing soldier.
38:02Supercharged with sugar that the caterpillar stole from the leaves.
38:12Soon they will be ready to help the colony expand.
38:24Every year ants dig miles of tunnels.
38:28And excavate as much as 12 tons in every acre.
38:43This aerates and breaks down the leaf litter.
38:46Which fertilizes the soil.
38:56Trees with rich soil and ant protection produce more sugar.
39:00They're brighter.
39:03And they will hang on to their leaves for longer during the fall.
39:15Despite the battles raging through the forest, billions of leaves continue to produce sugar.
39:28This is transported down the trunk where it's stored to replenish the tree's reserves.
39:35Each will gain as much as 100 kilograms in weight before the end of the year.
39:52The yellow-bellied sapsucker has attracted a female.
39:56And in their nest they have four young chicks, just a few days old.
40:10Their parents bring back food 20 times every hour.
40:20It's exhausting keeping up with demand.
40:28The summer sap is sweeter.
40:30And it attracts a swarm of insects.
40:39This is why the father has been obsessively digging wells.
40:44Because the sap leaking from them is now bait.
40:53And not even the tree's allies, the ants, can resist a nibble of the free-flowing sugar.
41:02For the chicks to grow, they need protein.
41:08Sugar-coated bugs make up two-thirds of their summer diet.
41:17Because of the constant supply of insects, the chicks increase in weight by 16 times in just four weeks.
41:34And they're already learning the art of tapping for themselves.
41:43In three months' time they will depart the cooling forest for warmer climates in the south.
41:50This will give the trees a chance to repair the damage before the summer ends.
42:10This female rattlesnake has spent three months basking in the sun.
42:14But daytime temperatures are now dropping as low as 14 degrees Celsius.
42:22Being cold-blooded, she's the first in the forest to feel a chill in the air as the days draw
42:28in.
42:32She's getting too big for her skin, but yawning widely helps to loosen it.
42:48And snags in the leaf litter help her to undress, peeling away the scaly layer.
43:07This lethal hunter is now ready.
43:26In a safe and secure place, specially adapted for filming, she waits.
43:49Through the night, months of preparation comes to an end.
43:57She's given birth to seven tiny rattlesnakes.
44:05Only 20 centimetres long, and already their sharp fangs are fully loaded with potent venom.
44:16Unlike most other snakes, timber rattlesnakes carry their babies inside their bodies to keep them warm.
44:25And there's one more on the way.
44:55Closing and
45:05The mother's work doesn't end there.
45:08Her maternal bond is strong.
45:14Having the fiercest mother in the forest,
45:17there's very little that could threaten these baby snakes.
45:25One by one, they snuggle into the safety of her coils.
45:38It won't be long until the cooling fall weather
45:41forces New England's rattlesnakes to lead their babies
45:45to underground dens,
45:47where they will hibernate as families until the spring.
46:02The shortening days and cooling weather
46:05triggers a change in the behaviour
46:07of New England's biggest animal.
46:13Male moose have been growing their antlers all year,
46:17and now they're dressed to impress.
46:25And finally, the females are open to their advances.
46:32But some moose have more luck than others.
46:41This younger male has been following a female for weeks
46:45in the hope of getting her attention.
46:50It's tiring work, and to make matters worse,
46:54she's still caring for a calf.
47:04But with antlers like this,
47:06how could she possibly resist?
47:12He decides to make a bolder move before a bigger bull shows up.
47:21Lip smacking makes his intentions clear.
47:31Her scent is irresistible.
47:43Not the response he was hoping for.
47:50Urination gives him a sign that she's still not in the mood.
47:56Even after weeks of trying to court her,
48:00persistence doesn't always pay off.
48:06Fortunately, every year,
48:09thanks to the nutrition from the forest,
48:11a moose grows a bigger rack.
48:16And next time, maybe his antlers will be big enough
48:19to impress the choosy female.
48:35With the temperature now constantly below 10 degrees,
48:39the leaves can no longer work efficiently,
48:42and with less than 12 hours of sunshine a day,
48:45they have less time to create sugar for the trees.
48:50There comes a point
48:51when they are no longer earning their keep,
48:54and the tree must start to close down for the winter.
49:04At first, the effects are subtle.
49:06Individual leaves start to turn yellow.
49:14Like tiny factories closing down,
49:17the green pigment inside each cell is dismantled.
49:24The tree salvages all that it can,
49:27carrying it down in the sap to be stored in the tree's trunk.
49:32The cooling weather quickens the process
49:36until the Midas touch of fall
49:38turns entire forests golden.
49:55But this is only just the beginning
49:57of the most magical transformation of all,
50:01the fall in New England.
50:07While most trees are already preparing for the winter,
50:12some also take this opportunity
50:15to secure a future for their offspring.
50:21They drop millions of winged maple seeds and acorns.
50:36Many will soon be safely hidden beneath leaf fall
50:39to await the nourishing warmth of spring.
50:47But they've been spotted.
50:50Despite the cover,
50:52there's one animal who is able to sniff out a fresh nut
50:55amongst the leaf litter.
50:58A chipmunk.
51:02His small size means that he's unable to pile on enough body fat
51:06to survive hibernation through the winter.
51:12And just when reserves are looking a little thin,
51:16a new airdrop is delivered by the trees.
51:24Perfect timing.
51:26If he can stockpile enough in his secret caches.
51:36He can squeeze four acorns into his cheek pouches,
51:40allowing him to collect up to 160 a day.
51:48It takes a lot of work to amass a big stash.
51:51But there's always one who's less prepared to put in the hours.
52:00A lazy chipmunk.
52:03He's spotted his neighbour's acorn
52:05and where it's being hidden.
52:09It's too tempting.
52:15But it's not an easy steal.
52:37This is one chipmunk determined to protect his stash.
52:44The chipmunk is a hero of the forest.
52:47Because even after all that work,
52:49he will forget where he's buried some of his hard-earned treasure.
52:55And protected underground,
52:57the seeds have a better chance of germinating.
53:03Whether they are a tree's enemy or an ally,
53:05the animals of New England have conspired
53:08to make the fall a season of beauty.
53:11And one thing is for sure,
53:13in the end,
53:14it's the entire forest that wins.
53:18And as the trees make their final preparations for winter,
53:22the best is yet to come.
53:33As the temperature drops towards freezing,
53:37the trees increase the speed
53:38at which they drain the leaves of their goodness.
53:42A magical new chemical is conjured up
53:45from within the leaves of the maple and oak trees.
53:51Red anthocyanin.
53:56It keeps the sap flowing for longer
53:58as the temperature plummets,
54:00so the trees can hold on to their leaves
54:03and extract every last drop of sugar.
54:11The reds and oranges join the golds,
54:15and together they set the forest ablaze.
54:22From an ocean of green,
54:25every tree becomes an individual.
54:32Red maples and oaks burn in shades of red.
54:46Sugar maples glimmer in orange.
54:52And for just a few weeks every year,
54:55New England is a wonderland of colour.
55:21These colours can be seen from space,
55:24spreading across this corner of America
55:27America like wildfire.
55:32The spectacle is intense, but brief.
55:37As the last of the nutrients and sugars
55:39are extracted by the trees,
55:41billions of leaves hang on tenterhooks.
55:46All it takes is a breeze.
56:00It's the last chance for their most persistent enemy to feast.
56:13Caterpillars, in a hungry race against time.
56:29Leaf miners are still feeding as the leaf changes around them.
56:33They eat all that they can,
56:35before a quick getaway.
56:40Some caterpillars chase the colour through the fall.
56:46The spicebush swallowtail swaps the green costume of summer
56:50for a golden coat.
56:57And having had her fill,
56:59she sheds this new skin to form an overwintering pupa
57:03that, like a leaf, fades to brown.
57:14Many other caterpillars turn red and orange in the fall,
57:19and as the leaves lose the last of their sugar,
57:22they climb to the edge of a leaf
57:25and take a leap of faith.
57:35Amongst the leaf litter,
57:37they seek out a refuge from the winter.
57:41In the spring,
57:43they will emerge as moths
57:44and unleash a new generation of caterpillars
57:47onto the forest.
57:55It's the end of October
57:57and the planet's most colourful forest fades
58:00as the last leaves fall.
58:03They have given the trees
58:05all that they need to survive.
58:11Until the battles begin again next year.
58:35We go from all that beauty on BBC Two
58:37to messy, M-themed matters on QI in a moment.
58:42We go first.
58:45We go with the 21st century
59:01to destroy the tej safety
59:01and to fight as the