- 28 minutes ago
Secrets of the Enchanted Forests | Seasonal
2023 | Επ. 2/6 | HD
Διασχίζουμε τα πλουσιότερα και πιο ποικιλόμορφα δάση του πλανήτη, από την τροπική ζώνη μέχρι τους πόλους και παντού ενδιάμεσα. Γνωρίζουμε τους άγριους κατοίκους αυτών των μαγικών οικοσυστημάτων και μαθαίνουμε πώς τα δάση συνδέουν και θρέφουν τις ζωές αμέτρητων ειδών.
Παρακολουθούμε τις εποχές να αλλάζουν και μαθαίνουμε πώς τα δέντρα και τα ζώα βοηθούν το ένα το άλλο να επιβιώσουν. Βλέπουμε τις ανοιξιάτικες πυγολαμπίδες να χορεύουν, ανακαλύπτουμε καλοκαιρινούς μύκητες που δροσίζουν τα καταπονημένα δέντρα και προετοιμαζόμαστε για τις μεταναστεύσεις του φθινοπώρου καθώς τα φύλλα αρχίζουν να πέφτουν.
2023 | Επ. 2/6 | HD
Διασχίζουμε τα πλουσιότερα και πιο ποικιλόμορφα δάση του πλανήτη, από την τροπική ζώνη μέχρι τους πόλους και παντού ενδιάμεσα. Γνωρίζουμε τους άγριους κατοίκους αυτών των μαγικών οικοσυστημάτων και μαθαίνουμε πώς τα δάση συνδέουν και θρέφουν τις ζωές αμέτρητων ειδών.
Παρακολουθούμε τις εποχές να αλλάζουν και μαθαίνουμε πώς τα δέντρα και τα ζώα βοηθούν το ένα το άλλο να επιβιώσουν. Βλέπουμε τις ανοιξιάτικες πυγολαμπίδες να χορεύουν, ανακαλύπτουμε καλοκαιρινούς μύκητες που δροσίζουν τα καταπονημένα δέντρα και προετοιμαζόμαστε για τις μεταναστεύσεις του φθινοπώρου καθώς τα φύλλα αρχίζουν να πέφτουν.
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LearningTranscript
00:01Υπότιτλοι AUTHORWAVE
00:02In a realm of constant change,
00:06where nature is a slave to the ticking clock,
00:11Earth's seasonal forests
00:14are the most dynamic of them all.
00:19From armies of vigilante insects
00:23to a pilgrimage from ocean to tree canopy,
00:27the march of the seasons inspire some to burn bright and brief,
00:33and others to make an epic journey into the unknown.
00:39This is a world of boom and bust.
00:44All must dance to the beat of nature's seasonal drum.
00:54Take a journey through our planet's kaleidoscope of forest realms.
01:01From the frozen boreal in the north,
01:05to the tropical jungles that hug our equator.
01:11From mountain peaks to the ocean depths.
01:18Marvel at the magic and drama
01:23that unfolds as we reveal
01:29the secrets of the enchanted forests.
01:46These are the monsoon forests of Borneo.
01:53Straddling the equator, spring, summer, autumn and winter
01:57hold no sway here.
02:02But these are seasonal forests all the same.
02:07One dramatic annual shift
02:09transforms this forest each year.
02:13It's so powerful that it has driven
02:16a once social animal into a life of solitude.
02:35This female orangutan gave birth just four months ago.
02:42It's her first baby.
02:46But, like the rest of her species,
02:49she's a single mum,
02:51with no family or troop to show her the ropes.
02:56She relies on instinct
02:58and an intricate knowledge of this forest,
03:02passed down through generations.
03:07Their bond is strong.
03:10She is all things to him.
03:14Provider.
03:16Bridge.
03:20And most importantly,
03:22she is his teacher.
03:27She has seven years to teach him everything he needs to know
03:31about surviving in this monsoon forest,
03:34as he will spend the rest of his adult life alone.
03:42It's the dry season.
03:46So today's first lesson
03:48is how to find a secret source of water.
03:57in a tree nook 40 metres above the ground.
04:12But he'd rather go in search of food.
04:19Mum has over 400 different types of fruit in this forest
04:24to introduce him to.
04:30But at this time of year,
04:32food of any kind is hard to find.
04:42This giant male has spotted one of the last remaining durian fruits.
04:57From a safe distance,
04:59they hungrily watch the male tuck in.
05:04and the baby learns one of the most important lessons of them all.
05:10Orangutans do not share food.
05:15Unlike nearly every other primate species,
05:18they are solitary creatures.
05:24It wasn't always this way.
05:27Like their ape cousins,
05:29orangutans used to be social.
05:32But after the last ice age,
05:35the forest changed.
05:40Now, with food appearing seasonally,
05:43it could no longer support large troops.
05:49In a boom-or-bust world,
05:52each had to go it alone.
05:57Without a troop for support,
05:59this mother had to become an expert
06:02in the ways of the forest.
06:07And she knows change is coming.
06:12Knowledge learned from her own mother
06:14tells her that once a year,
06:16the monsoon brings a life-saving deluge of rain.
06:23But the force is unpredictable.
06:26And this year, the rains are late.
06:32Orangutans have learned to be patient.
06:40Eventually, the sky will deliver.
06:46From no rain to over 40 centimetres falling in a single month,
06:52this change to wet season finally reawakens the forest.
07:00And after a quick demonstration in umbrella construction,
07:06it's finally time to teach her son
07:08where to find the now-ripened fruit.
07:17With bellies full,
07:19they can practise making their beds.
07:23Tomorrow will be yet another day of homeschooling.
07:28The orangutans' reclusive instinct
07:30is now etched into their DNA.
07:37By falling in sync with the powerful monsoon,
07:42they have found a way to survive the all-or-nothing nature
07:46of this seasonal forest.
07:59Moving away from the equator,
08:01temperate forests have four separate seasons to adapt to.
08:08For a forest, every changing season presents an opportunity.
08:14and spring in the northern hemisphere means babies.
08:23But too much new life each spring
08:26can pose a supply-and-demand problem.
08:32Every now and then, trees conspire together
08:37to act as nature's most synchronised form of birth control.
08:42In these woods, reproduction requires teamwork
08:46between tree and animal.
08:49And it all starts with a burst of spring blossom.
08:58Pollinated flowers transform into fruit, nuts and seeds,
09:07providing a feast for the woodland animals,
09:10providing a feast for the woodland animals,
09:11who spread them far and wide.
09:19When the balance is tipped,
09:21too many seeds are eaten,
09:24leaving too few to germinate.
09:29The trees must find a way to take back control.
09:35And they must do it together.
09:40Every few years, the trees collude.
09:44To produce a bumper crop of fruits or nuts,
09:48known as a mast year.
09:52A seasonal glut that yields more food
09:56than the animals could possibly eat.
10:00Leaving more seedlings the chance to take root.
10:05This strategy is not confined to temperate forests.
10:10Trees across the planet use this method to gain the upper hand.
10:19Now, the trees have to make sure this new bounty of food
10:23does not encourage a corresponding baby boom
10:26in the forest animals the following year
10:29that will still go on to eat it all.
10:34So they cunningly follow their generous mast years
10:40with several meagre ones.
10:44The shift from abundance to scarcity
10:47curbs any plans for legions of offspring
10:50and more mouths to feed.
10:56And balance is once again restored.
11:02It's a master plan.
11:04It leaves the animals guessing,
11:07keeps populations in check
11:09and most importantly,
11:11it shows who really holds the power.
11:18Across hundreds of kilometres,
11:21trees can precisely synchronise their mast years
11:25so the overabundance happens all at the same time.
11:31How they do this is still one of the forest's greatest mysteries.
11:49As each season ripples through the forest,
11:54orchestrating events like a musical conductor,
11:57one of the forest's tiniest residents
12:00is looking for a stage to put on the performance of a lifetime.
12:13For this Firefly, Late Spring brings about the most important night of her life.
12:23She's just emerged from her underground lair
12:26and is still getting used to her new adult beetle body.
12:32She's looking for love.
12:35And tonight is her chance to shine.
12:41But this isn't a solo show.
12:46If she has timed it right,
12:48she'll emerge with thousands of other Fireflies.
12:56If her timings are off,
12:58she'll have missed her one opportunity.
13:04She is looking positively radiant.
13:11Her abdomen contains bioluminescent chemicals
13:14that, once mixed, she ignites by pumping in oxygen.
13:20She then regulates this reaction to turn her glow into a pulse.
13:34Winged males reveal themselves with their own dazzling display.
13:45She's looking for the brightest light,
13:50indicating a strong, virile male.
13:56bingo!
14:03She adjusts her rhythm,
14:06mimicking his flashes.
14:17Eventually, the pair are completely in sync.
14:24She's won him over.
14:28Other females may keep their light flashing all night,
14:33drawing in multiple partners.
14:37But she seems satisfied with her choice.
14:47When her twilight tryst is over,
14:50in the cold light of day.
14:54Her choice is a little underwhelming.
15:00Much smaller than she,
15:02the male Fireflies are far less glamorous than the females.
15:10Dating in the dark definitely works in his favour.
15:16In any case, a Firefly's relationship is short-lived.
15:26Their entire lives are geared towards this seasonal light show,
15:31and he will die soon.
15:35She'll carry on to lay her now fertilised eggs.
15:39And then she, too, will turn off her light forever.
15:47Destiny fulfilled.
15:53For many, these glittering courtship displays are a prelude to a new radiant summer.
16:05This change in season can trigger an influx of picky visitors.
16:20When seasonal extremes only allow small patches of forest to thrive,
16:26some animals could find themselves living tooth-by-jowl with a monstrous neighbour.
16:34In Colombia, a vast savannah stretches for over 500,000 square kilometres.
16:44Despite the extreme shifts between the wet and dry seasons here,
16:49trees have found a way to survive.
17:02When the rains come, the rivers overflow,
17:09bringing long-awaited water and nutrients
17:13to the green ribbons of forests that line their banks.
17:22These unique gallery forests are the only strips of trees for hundreds of kilometres.
17:30They are crucial for thousands of migratory birds
17:34visiting each year to this one spot of prime real estate.
17:45But the birds are fussy.
17:50Everyone wants waterside views,
17:53stable foundations
17:56and a source of sturdy branches for nest building.
18:01The higher the spot, the better.
18:09This male great egret didn't bag the penthouse.
18:15Not to worry, he's looking particularly fabulous this year.
18:20And hoping his plumage impresses the incoming females.
18:31This potential mate shows an interest.
18:35But she wants to check out his nest before committing.
18:41It's first rate.
18:43Close enough to water to take advantage of the early summer blooms of plant and fish life.
18:50But also hidden away in the branches for a little privacy.
18:59She approves.
19:05A month later, the entire woodland is a frenzy of demanding chicks.
19:15And frantic parents.
19:23But as the egret chicks begin to fledge,
19:27this perfect location might not be so perfect after all.
19:38Beneath them,
19:41a monster is stirring.
19:49The arrival of the rains has awoken this caiman from her state of torpor.
20:00With the forest floor now a watery highway,
20:05she has easy access to the nesting areas.
20:13Weak from a season of not eating,
20:22from the sky.
20:23Ideally, her next meal would simply fall from the sky.
20:40For some,
20:43the dream riverside home is the best place for her.
20:48has turned into a nightmare.
20:52A nightmare.
20:56A nightmare.
21:09For the lucky ones, life continues.
21:12...και όταν υπάρχουν στους τελευταίους.
21:20Η φορή δεν υπήρχε εδώ,
21:23...ερίζεσαι για την αυτοσία της καταλήθειας κατάστασης.
21:30Η γύρω πλανδιά των φορήτων των φορήτων
21:35...και όμως ουσιαστήριος πρέπει να υπάρχει.
21:52Υπότιτλοι AUTHORWAVE
22:12Υπότιτλοι AUTHORWAVE
22:42In an attempt to preserve water, they desperately shed their leaves,
22:49forfeiting their chance to generate any more food until next spring.
22:55But they won't starve.
22:58Deep underground, a mysterious saviour is coming to their rescue.
23:10Within the soil, a fungal network of gossamer-like strands extends its reach below the entire forest,
23:20connecting to every tree root.
23:24The fungi shuttle much-needed water and sugars from tree to tree,
23:31delivering a life-saving tonic to those who need it most.
23:42This interconnected partnership between a tree and its fungi
23:46can help save entire forests unable to cope with the rising temperatures of our summer seasons.
24:06Any tree weakened by the heat can be vulnerable to attack
24:14by caterpillars, beetles, and aphids.
24:23But in this orchard, a winged army of protectors are ready to keep any potential assailants at bay.
24:37These hornets rule over all other insects in this forest,
24:43serving like pest control officers,
24:47keeping every other bug population under control.
24:52Their headquarters are located inside this hollowed-out tree.
24:59The hornets have spent the summer expanding their command.
25:04Hundreds of new offspring requires a bigger nursery.
25:11The workers recycle the dead wood from the forest
25:15to construct the new paper-thin walls of their nest.
25:21Their queen single-handedly gave birth to this entire colony.
25:27Her sole duty now is to deposit new eggs into each empty cell,
25:33spawning the next generation of pest controllers.
25:42Hornets are voracious hunters,
25:44and they target the food that is most abundant.
25:51So any summer swarms of insects tormenting the trees
25:55will be exterminated.
26:14Powerful jaws dismember their prize.
26:25Powerful jaws dismember their prize.
26:27due to their extreme hourglass shape,
26:30an adult hornet cannot digest its prey.
26:39But the plump larvae can.
26:43So the workers deliver the food to their immature grubs.
26:51their reward is a liquefied meat smoothie regurgitated back into their mouths.
27:08By summer's end, the colony has reached its peak.
27:16The ageing queen has given the gift of 1,500 eggs to her colony.
27:22Now she prepares to pass her crown to a new ruler.
27:31Her final act of service is to produce next year's batch of queens.
27:40Before her body is returned to the forest.
27:53As the day is cool, the summer bounty of food is ending.
28:03Now redundant, even the workers can sense their time is coming to an end.
28:13The colony's only hope now rests with their future queens.
28:18These princesses must build up their reserves to see them through the winter.
28:26So the last remaining larvae are sucked dry.
28:32A sacrifice to the future queens.
28:49The new queen leaves the ruins of the past empire behind.
28:54Never to return.
28:59Next year, she'll start her own colony.
29:03And raise an army to keep her forests safe.
29:10But her own fate is inevitably sealed.
29:13And one day, she too will fall with the autumn leaves.
29:26In one forest, a seasonal pilgrimage leads millions of fish from the ocean up into the canopy.
29:36And how they got there is a story like no other.
29:41A true miracle of nature.
29:47It's late summer in Alaska.
29:52As the days grow shorter, the trees here are preparing for winter.
29:58They have slowed their growth.
30:00And now plough all their energy into building their winter stores.
30:08So they need all the food and water they can get their roots on.
30:16In this forest, nutrients tend to wash downriver.
30:22So nature had to find a solution to bring them back upstream.
30:30And it originates far, far away from North America's seasonal forests.
30:38Deep in the North Pacific.
30:45These salmon have been spurred to make the journey of a lifetime.
30:52The changing season is pulling them from their bountiful ocean home.
30:58Towards the land and the exact river where they were born years before.
31:09Their instinct drives them thousands of kilometres upriver.
31:17Using the Earth's magnetic field, like a compass, to help navigate their way.
31:25But the sheer effort of fighting against the freshwater flow takes its toll.
31:35Hump-backed and disfigured, these males barely resemble the sleek silver bullets from their ocean life.
31:45The fish carry valuable ocean nutrients with them, essential for the growth of the trees.
31:53But for the forest to access those nutrients, it needs help.
32:08For Alaska's brown bears, the annual arrival of the salmon marks the start of their fishing season.
32:49During these high times, the bears need only eat the most nutritious parts of the fish.
32:56The fish, fat-rich brains,
33:00skin,
33:03and eggs.
33:06The rest of the carcass is tossed aside,
33:10leaving plenty for others to take advantage of.
33:15Including the forest.
33:21Here, the bears leave tons of leftover fish to decompose.
33:33Releasing rich nitrogen into the soil.
33:39A key nutrient for the trees.
33:44Helping them grow three times faster than elsewhere.
33:48Making them stronger.
33:52And more nutritious.
33:55For all that consume them.
33:59And when the bears have digested the fish,
34:02they further feed the forest, with rich droppings and urine.
34:10Bears fish all along these migration rivers,
34:14feeding the forest as they go.
34:19For the salmon that make it past the bear gauntlet, they break off.
34:24To spawn in the shallows.
34:40It's their final act.
34:43They put every ounce of energy they had into battling their way here,
34:48for the chance to reproduce just once.
35:01But their effort ensures a new generation of salmon will continue the cycle.
35:09Providing a vital supply of nutrients to these forests.
35:17Everything that lives here benefits from the tireless efforts of a
35:21is a very determined fish.
35:24And an arduous 3,000-kilometre journey.
35:30Bringing nourishment to an entire forest from ocean to canopy.
35:43Throughout the seasons, much of the pine forests of Alaska remain evergreen.
35:51But as summer draws to a close in temperate forests around the world,
35:58each tree must make a critical decision about its future.
36:08The sun is losing its power, and the drop in temperature triggers a beautiful transformation.
36:18The trees of a forest often work in synchronicity.
36:21But this time, it's different.
36:27As the daylight hours decrease, the sun no longer provides enough energy for the leaves to turn it into food.
36:36Soon, a tipping point is reached.
36:39When holding on to their leaves becomes more of a burden than a benefit.
36:46Each makes its own judgement on when to shed.
36:52It's now recognised that trees have memories and call on their previous experience to make this crucial decision.
37:01In fact, a more anxious tree may drop early based on past traumatic incidents.
37:09No one wants to get it wrong.
37:13Too early and you lose the chance to make the optimum amount of food for the winter.
37:19Too late and the frost might damage the tree.
37:22Any remnants of water in the leaves could cause them to rupture like a burst frozen pipe.
37:33When the decision is made, the green chlorophyll pigments used to harvest the sun's energy are broken down.
37:42Revealing a blaze of gold.
37:47And red.
38:07The tree, its crown now stripped bare, is ready to sleep.
38:18Protective buds appear where the leaves once connected to the stems.
38:23They contain a chemical that places the tree into a state of silent slumber.
38:30Before the cold really sets in.
38:40As autumn creeps into winter, the once buzzing forest takes on an eerie emptiness.
38:53So, where do insects go at this time of year?
39:05Ladybugs, a welcome sight in summer, search for dark sheltered spots where they can rest or diapause undisturbed.
39:20A group of ladybugs is called a loveliness.
39:24And this friendly bunch prefers to hibernate in company.
39:29So, once an individual has found a cosy crevice, they send out a chemical scent to call in others to
39:38join the winter bundle.
39:48As temperatures drop closer to zero, many other insects will not survive.
39:56But they have preserved their legacy in the form of eggs, hidden somewhere protected within the forest.
40:09For a select few, winter is their time to shine.
40:16The aptly named winter moth has picked this season to breed.
40:23Emerging from the soil in early winter, the males flit about looking for a mate.
40:31But their female counterparts, laden down with eggs, have given up attempting to fly altogether.
40:41They just haul their way up the tree trunks.
40:48It's too cold for energy-sapping courtship displays here.
40:52She simply releases a pheromone and lets the males come to her.
41:03She'll lay her eggs in the cracks of the same tree trunk.
41:09The winter moths die soon after breeding.
41:13A whole adult life lived, having never felt warmth.
41:21Others, such as our future hornet queen, use the forest's natural insulation, leaf litter,
41:29to wait out the winter in a secret hideaway.
41:35Having already mated, the new queens will emerge from their leafy lairs in spring.
41:46But they won't return to their old home.
41:52Hornets never reuse an abandoned nest.
42:00The reign of this paper palace is now over.
42:13While winter sees one monarchy pass on to the next generation,
42:17a different monarch is on the rise.
42:23A new fleet of genetically elite, age-defying, supreme beings have been born.
42:33Poised to invade the US.
42:40In these secluded eucalyptus groves on the coast of California.
42:50Monarch butterflies are arriving.
42:53In their thousands!
43:05Their monumental journey began over 4,800 kilometres away in Canada.
43:15The drop in temperature and changing tilt of the earth
43:18triggered a mass exodus in search of some winter sun.
43:25in the sea.
43:28No ordinary monarch could fly that distance.
43:33These butterflies are made from stronger stuff.
43:37They are the super generation.
43:42Born bigger, more powerful, and with the gift of longevity,
43:47these formidable flyers live eight times longer than the average monarch.
43:56built purely to make the migration to this one small patch of forest.
44:11These eucalyptus trees are not native to this area.
44:15But the monarchs have chosen them as their perfect home in the sun.
44:24The trees create the ideal microclimate for them.
44:29The canopy and branches provide wind protection.
44:34And long, thin leaves filter the California sunlight.
44:39Giving the butterflies dappled light and cooling shade that they need.
44:46And the slender leaves are easier for their little legs to grip.
44:53They didn't find this forest by chance.
44:58Despite never having visited this site before,
45:01monarchs have been found to migrate to the exact same tree as their ancestors years previously.
45:09Its location is now baked into their DNA.
45:15And they know how to find this very tree through a remarkable sense of direction and time.
45:24These tiny creatures tell the time by using their antennae.
45:31Coupled with super-powered eyes that decipher the sun's position, they rarely get lost.
45:42This migration isn't all about the mild weather.
45:46It also means more potential mates to choose from.
45:53The air fills with the scent of female pheromones.
46:03And long, elegant courtship dances commence.
46:22Eventually, this super-generation's time must come to an end.
46:29And they will die shortly after laying their eggs.
46:37Leaving them to hatch in the California sunshine.
46:42But there is nothing super about their offspring.
46:46Without the globetrotting stamina of their parents,
46:49they will only make a fraction of the journey back to Canada.
46:54Before mating and leaving the next leg to their progeny.
47:01It takes three more generations of butterflies to relay race each stage back to their Canadian homeland.
47:09Just in time for summer.
47:12By August, the next batch of super-powered monarchs will be born.
47:18And so the ticking clock of nature's changing seasons starts its cycle all over again.
47:31Every new season brings dramatic change from the boom of spring to the challenges of winter.
47:42These unstoppable forces are what define the cycles of life in our planet's seasonal forest.
47:51One lastgrading and projection starts the same.
48:00This place shows three openings back to your spacecraft,
48:00These beginnings burn in the years of long-term destiny,
48:00Geralt Jr.
48:00Ευχαριστώ.
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