- 23 minutes ago
The ancient temples of the Maya still tower over the jungles of the Yucatan, where jaguars, monkeys and tropical birds make their home. Beneath the forests a vast, watery underground world is still being explored.
带您领略尤卡坦半岛的森林——这片充满魔力的玛雅大地。这里森林地下的水下世界尚待进一步探索，而它正是动植物及人类在旱季得以生存的关键所在。
尤卡坦半岛拥有古老而茂密的丛林，卡拉克穆尔（Calakmul）等巍峨的玛雅神庙至今仍矗立其中。
• 野生动物：这里栖息着美洲豹、蜘蛛猴、吼猴、莫雷莱鳄（Morelet's crocodile）以及色彩斑斓的热带鸟类（如厚嘴巨嘴鸟）。
• 水下世界：探索该地区隐秘的石灰岩天坑与洞穴网络——即著名的“天然井”（cenotes）；在严酷的旱季，它们提供了生存必需的淡水资源。
• 人文风情：聚焦当地传统，例如世代相传的家庭式森林园艺耕作，这种耕作方式高度依赖于附近的天然井。
带您领略尤卡坦半岛的森林——这片充满魔力的玛雅大地。这里森林地下的水下世界尚待进一步探索，而它正是动植物及人类在旱季得以生存的关键所在。
尤卡坦半岛拥有古老而茂密的丛林，卡拉克穆尔（Calakmul）等巍峨的玛雅神庙至今仍矗立其中。
• 野生动物：这里栖息着美洲豹、蜘蛛猴、吼猴、莫雷莱鳄（Morelet's crocodile）以及色彩斑斓的热带鸟类（如厚嘴巨嘴鸟）。
• 水下世界：探索该地区隐秘的石灰岩天坑与洞穴网络——即著名的“天然井”（cenotes）；在严酷的旱季，它们提供了生存必需的淡水资源。
• 人文风情：聚焦当地传统，例如世代相传的家庭式森林园艺耕作，这种耕作方式高度依赖于附近的天然井。
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TVTranscript
00:03In the heart of the Americas, where continents collide, there's a land full of natural riches.
00:32A land of towering giants, scorching sands, and secret rivers, where great civilizations rose and fell.
01:01To succeed here takes passion and spirit.
01:10This is a country rich in color and culture.
01:18A festival of life.
01:33This is Mexico.
02:04In Mexico, it's a country rich in Mexico.
02:06It goes far south.
02:07There's a forest full of secrets.
02:15It's March, the peak of the dry season.
02:21This pool is fast disappearing, and it draws all the animals from the forest.
02:38Even the most elusive.
03:08For a young Morelei crocodile, the pool is also a hunting ground.
03:24There's plenty of potential prey.
03:28Trouble is, most are far too big.
03:46Finally, a realistic target.
04:09Even at his size, sneaking up in such shallow water isn't easy.
04:21He needs to change his technique.
04:28Perhaps an ambush will work.
04:50Almost.
04:51Let's go.
05:20Success at last.
05:24But he's not the only crocodile here.
05:43And his taste of victory is short-lived.
05:53There's a reason water is so scarce in this corner of Mexico.
06:02This great forest, which stretches for almost 50,000 square miles, has no major rivers.
06:13And that's down to the region's unique geology.
06:21The forest stands upon a vast peninsula, the Yucatan.
06:32The entire peninsula is a gigantic slab of limestone.
06:39Limestone is incredibly porous.
06:44Any surface water swiftly drains away underground.
06:49And this shapes the lives of all who live here.
07:11For seven months of the year, virtually no rain falls.
07:16And by April, much of the forest is barren.
07:21For a mother spider monkey, this can be challenging.
07:27She needs to produce enough milk to feed her baby.
07:37And that requires plenty of fresh fruit.
07:47Sometimes that means traveling over two miles each day.
07:55But with long slender fingers and no thumbs to get in the way, this is child's play for an animal
08:02designed for life in the treetops.
08:23She's taking her youngster to a special place where she knows there's fruit all year round.
08:47The ancient city of Calakmul, once one of the most powerful in the Maya civilization.
08:59In the 7th century, this city was home to 50,000 people.
09:11The people of Calakmul cultivated trees that would fruit throughout the year.
09:22Centuries later, these ancient gardens have left a lasting legacy.
09:40There's more fruit here than anywhere else in the forest, even at the height of the dry season.
09:50Over countless generations, the monkeys have passed this knowledge on to their youngsters.
10:10The people of Calakmul is the built-in' transition from the forest.
10:34At its peak in the 8th century, the Maya civilization grew to almost 13 million people.
10:49Theirs was a highly sophisticated culture, advanced in mathematics, language, and astronomy.
11:01The huge limestone temples built to worship their gods are a lasting testament to great feats of engineering.
11:15Almost every other ancient civilization in history has been built beside a major river.
11:23So how did the Maya manage without one?
11:29There are almost one and a half million direct descendants of the ancient Maya living in Mexico today.
11:38Don Roque and his wife, Don Yasu, live on an isolated farm in the heart of the Yucatans forest.
12:04This farm has been in Don Roque's family for generations.
12:11With his children grown up and left home, nowadays it's just him and Don Yasu.
12:22They live off the land in a way little changed since the times of their ancestors.
12:38But there's more to their farm than meets the eye.
13:00A huge natural well known in the Yucatan as a cenote.
13:17A cenote is a collapsed cave.
13:23Over thousands of years, rainwater has eroded the soft limestone on the surface.
13:29Eventually, the roof weakened and fell.
13:41This cenote provides Don Roque with water all year round.
13:53But it's far from unique.
14:01It's one of several thousand cenotes scattered across the peninsula.
14:11Cenote comes from the Maya word zonut, meaning holes with water.
14:24It was these mysterious pools that enabled the Maya civilization to flourish without a major river.
14:37And the greatest ancient cities were founded beside them.
14:48Each cenote is an oasis.
14:55The surrounding forest remains lush, even at the height of the dry season.
15:06Filtered through the limestone, the water is full of minerals.
15:13It supports a unique community of plants and animals.
15:20Some fish in the Yucatan cenotes are found nowhere else on Earth.
15:33Within the dense forest, a cenote can remain hidden even when close by.
15:42But the Maya had an almost surefire way of finding them.
15:50The distinctive call of the turquoise-browed mutt-mutt.
16:01Virtually every cenote has its own colony.
16:07Elsewhere, mutt-mutt-mutt prefer to nest alone, digging their burrows along riverbanks.
16:17Here in the Yucatan, they're forced together, sharing limited space on the cenote's soft limestone walls.
16:29Before a male can start looking for a mate, he needs to secure a nest site.
16:36But this cenote is already crowded.
16:39Seventeen other pairs are nesting here.
16:47If he's to fit in, this new arrival must use the right body language.
17:04A raised turquoise brow is intended to intimidate rivals.
17:27The pendulous tick-tock of their tails has earned mutt-muts the nickname, clock birds.
17:40This male must persevere if he wants to breed this year.
17:51At last, he's earned his own little ledge of limestone.
18:02With a gift of food, he can get down to the business of attracting a mate.
18:17There are so many cenotes in the Yucatan because of a dramatic event that changed the history of life on
18:25Earth.
18:37Around 65 million years ago, a huge meteorite collided with what is now the Yucatan's north coast.
18:48Its effect was so catastrophic, it's believed to have wiped out the dinosaurs.
18:55In an instant, the impact fractured the limestone platform, creating what has become known as the Ring of Cenotes.
19:05Satellites have revealed over 200 clusters around its crater.
19:14Satellite technology is also helping modern-day explorers in the Yucatan.
19:21And new cenotes are still being discovered today.
19:25It should be about 50 meters that way, you see anything?
19:28Sam Meacham and Fred DeVos are part of an international community of cave divers
19:34that has been exploring the Yucatan since the 1980s.
19:40I started out for the thrill of being able to explore something.
19:44And from a young age, I just was imbued with the desire to go out and explore this world.
19:51Each new cenote adds another piece to the puzzle.
19:57Ah, look at this, Sam. Wow.
20:01The moment of discovery, right? You can't beat it.
20:15In the last 30 years, cave divers in the Yucatan have revealed something extraordinary.
20:25The cenotes are not isolated wells.
20:33Each is connected by an intricate network of caves and passageways spreading like a spider's web across the peninsula.
20:49Divers have discovered over 350 caves,
20:54and nearly a thousand miles of flooded tunnels,
21:00including the two longest underwater cave systems on the planet.
21:08Sous-titrage Société Radio-Canada
21:08The end of this acontece is a young man.
21:09The end.
21:36Many of these caverns have seen fewer visits.
21:39More visitors than the moon.
21:43The great majority remains uncharted.
22:08For the ancient Maya, the labyrinth of caves was out of reach, but not beyond imagination.
22:16This secret underworld was held sacred.
22:21Home to the Twelve Gods of Xibalba, it was a place both feared and revered.
22:32But the ancient Maya recognized a link to this unknown world.
22:38Trees.
22:46Always plumbed into the water below, trees allow life above ground to flourish.
22:56No tree is better equipped to do this than the strangler fig.
23:02Its roots can reach 30 meters into the water below.
23:25Don Roque uses the fig's roots to enter the underworld.
23:31Navigating his way down steps carved by his grandfather over half a century ago.
23:38In the middle of the river, there was a place where he was born.
23:48And there was a place where he was born.
24:05At the bottom of the cenote, Don Roque has a secret garden.
24:16Here he cultivates a plant that wouldn't survive elsewhere on his farm.
24:22Coffee. Above ground, it's too hot and dry for coffee to grow.
24:34Down here, it's two degrees cooler and a lot more humid.
24:43Don Roque's cenote is also a haven for insects, food for a colony of resident cave swallows.
25:10By me, the swallows are intent on one thing.
25:15Breeding.
25:24The cenote provides everything they need.
25:33Down here, they have a ready supply of soft mud.
25:42They use this to craft their nests, together with fibers plucked from the hanging fig roots.
26:05All being well, in around a month's time, they'll each have a brood of up to five chicks.
26:18Don Roque's cenote has its own community of life, thanks to the constant presence of water.
26:24But the rest of his farm requires something more.
26:29He plants his land with a mixture of corn, beans and squash, in a tradition passed down the generations.
26:39A mix of crops helps maintain the fragile soil, which lies in a thin layer on top of the limestone.
26:48But he can't draw enough water from his cenote to irrigate an entire field.
26:56For his crops to grow, Don Roque needs it to rain.
27:05By late May, change is in the air.
27:12The Yucatan relies on weather systems that develop thousands of miles away.
27:22Gathering ever more water as they cross the Atlantic, they bring the seasonal rains.
27:34The ancient Maya believed the rain was a gift from the gods.
27:42For Don Roque, the old gods are very much alive.
27:56The most important of all is Jack, the life-giving god of rain.
28:28It is Jack who determines each thunderclap.
28:44Finally letting the rain fall.
28:561,200 years ago, something happened that sent the Maya civilization into a dramatic decline.
29:03Jack withheld the seasonal rains.
29:09The Yucatan was gripped by a series of devastating droughts.
29:20Over 80% of the population vanished.
29:31One by one, the bustling cities were abandoned
29:35and reclaimed by the forest.
29:46This year, the gods have been kind.
29:49By July, it's raining almost every day.
29:59This brings new growth to the forest.
30:02Good news for the Yucatan's noisiest residents.
30:16Howler monkeys.
30:21Their calls carry for over a mile.
30:28They howl to let neighboring groups know their whereabouts.
30:42This batch of the forest is worth protecting.
30:47The troop has found a tree with young, succulent leaves, a particular favorite.
31:04But a diet of leaves takes time to digest.
31:13So howlers spend up to 80% of their time resting,
31:18making them amongst the most peaceful of all monkeys,
31:22despite their fearsome calls.
31:28Baby howlers feed on their mother's milk until almost a year old.
31:34When they're hungry.
31:34This is much easier to digest.
31:51With his mother trying to sleep off her lunch,
31:56nap time can be a bit dull for a baby.
32:22All life in the Yucatan benefits from the rain.
32:36Trees burst into fruit.
32:45All the new plant growth provides food for an explosion of insect life.
32:51There are over 3,000 different species on the peninsula.
33:02The insects become food for others.
33:11Almost all the birds in the forest schedule their nesting
33:15to coincide with this seasonal bounty.
33:37The regular rain is also good news for Don Roque.
33:44In just six weeks, his scorn has shot up.
33:54In just six weeks, his scorn has shot up.
34:10But the explosion of plant eating insects could cause Don Roque problems.
34:18For his crops to thrive, he needs the help of a natural ally.
34:37In the heart of the Yucatan, there's a cave the locals call El Volcan de los Murciélagos.
34:59Every day, an hour before dusk, it erupts.
35:08Every day, an hour before dusk, it erupts.
35:22More than three million bats exit the cave.
35:37More than three million bats exit the cave.
36:12The ancient Maya associated bats with death.
36:20This was a swarm straight from the underworld.
36:29But bats are vital to life in the Yucatan, keeping its insect population in check.
36:37Each can eat its own body weight in insects every night.
36:49While the bats are focused on the insects, others are watching them.
36:58Gray hawks.
37:01And bat falcons.
37:05These birds are skilled aerial predators.
37:09Their talons perfectly designed to snatch the bats from the air.
37:33There are other, more surprising hunters here.
37:41Brown jays.
37:50They normally eat insects and fruit.
38:04But the brown jays here have developed a taste for bats.
38:20The jays don't use talons to catch their prey.
38:27They use their beaks.
38:29The wild jays are contagious.
38:37They use their身 as they need to hear.
38:49They use their food.
38:57The loss of 10 or so baths barely makes a dent on the swarm.
39:12Tonight, the colony will consume around 30 tons of insects, a vital service that keeps
39:21the entire forest healthy.
39:49It's late September.
39:52And it has rained almost every day for the last three months.
39:58Don Roque's corn is now fully ripe.
40:09It has rained almost every day for the last three months.
40:15It has rained almost every day.
40:23I'm going to put it in my hand.
40:26I'm going to put it in my hand.
40:50In a tradition dating back to the times of their ancient ancestors,
40:55the first corn of the harvest serves a special purpose.
41:04Doña Su crushes it to make a sacred drink called atole.
41:16This is offered to the gods in a ceremony of thanksgiving.
41:39In the land, the earth is filled with the heavens.
41:43It's very quiet.
41:51It's about to sing.
42:16from June to November the Yucatan receives a hundred centimeters of rain
42:26across the peninsula that's over 36 trillion gallons
42:40the cenotes are refilled
42:49but most of this water seeps through the limestone into the underworld
42:58the work of cave divers like Sam is furthering our understanding of the Yucatan's unique water
43:05system we're still exploring here and the more we explore the more questions we ask selfishly I
43:13hope we finish in my lifetime I don't think we will
43:24meter by meter the divers are mapping the underground labyrinth
43:31it's a painstaking process with every measurement taken by hand
43:39but this has revealed something remarkable
43:49the water in the caves isn't just locked within the limestone
43:55it flows
44:00the Yucatan's missing rivers are underground
44:23like all rivers they are compelled towards the coast
44:34here the fresh water meets salt water brought by the incoming tide
44:47this border is called the halo climb
44:54containing more dissolved particles the salt water is heavier and lies below the fresh water
45:03giving the illusion of a surface
45:10but after months of heavy rain the flow of fresh water prevails
45:19at the coast it leaves the underworld behind
45:29mangroves flourish in the mixture of salt and fresh water
45:35the roots provide ideal nurseries for schools of fish
45:44and gentle giants are drawn to the Yucatan's shores
45:55manatees come to drink at the outpouring of fresh water
46:08manatees come to drink at the outpouring of fresh water
46:19as the fresh water flows through the mangroves the trees release tannins staining it brown
46:47eventually the fresh water reaches its final destination
47:05it pours out into the gulf of mexico in huge volumes
47:10a
47:50Replenished by billions of gallons of fresh water, these vast coastal lagoons are the
47:56ideal home for a colony of the Yucatan's most colorful residents, Caribbean flamingos.
48:43It's been a good year for the colony, with nearly 15,000 new additions.
48:59Finding your cheek in such a big crowd isn't easy.
49:05But flamingos have incredibly good hearing, and her youngster has his own unique voice.
49:19Just six weeks ago, the cheek was little bigger than his mother's beak.
49:42These lagoons are full of brine shrimps.
49:47The vita carotene in these tiny crustaceans gives the flamingos their distinctive call.
49:57But it will be another two years before he starts to turn pink.
50:02Oh!
50:07Oh!
50:17Oh!
50:19Oh!
50:21Oh!
50:23Oh!
50:25Oh!
50:25Oh!
50:26Oh!
50:37Oh!
50:40Oh!
50:41Oh!
50:46Oh!
50:48Somewhere on the Yucatán's coast, as elsewhere on the peninsula, all owe their survival to
50:54the secret underworld.
50:56Without its great hidden rivers, this would be a hot, dry and hostile place.
51:05Born of a unique history, the underworld hidden beneath this vast forest gave rise to the
51:14ancient Maya civilization, and it remains the lifeblood of the Yucatán.
51:36Capturing the beauty of the Yucatán's underworld meant sending a film crew into one of the most
51:42alien environments on the planet.
51:48To do this safely required expertise.
51:53Between them, this team has over 50 years' experience diving on the peninsula.
52:02Cameraman Mike Madden was one of the pioneers of cave exploration here back in the 1980s,
52:08and Sam Meacham is part of a team currently mapping one of the region's two longest caves.
52:15There's a common misconception that cave divers are these adrenaline junkie risk-takers cheating
52:21death on every dive.
52:23Were tarantulas in our risk management form?
52:26When in fact, we're probably some of the most cautious people on the planet.
52:35There's a very real need for caution.
52:41All diving carries risks, but cave diving heightens these risks.
52:53Surfacing isn't an option if you run out of air.
53:01This particular cave system, known as Taj Mahal, was first explored in 1995.
53:09It has over three miles of flooded passageways, some descending almost 30 meters.
53:18Filming here poses another challenge.
53:20Most of the cave is pitch black.
53:25So the first thing the divers need to do is set up a highly specialized underwater lighting
53:30rig.
53:36Four 1200-watt lights, a hundred meters of cable.
53:46All of it has to be carried into the cave by hand.
53:56Lighting the caves on this scale is a new challenge for the team and draws on all their expertise.
54:05Since the 1980s, the dedicated work of divers like Sam and Mike has helped put nearly a thousand
54:12miles of the Yucatan's underworld on the map.
54:15But the vast majority remains uncharted.
54:19It's pretty amazing that, you know, 35 years after the beginning of cave diving exploration
54:26in this area, I would say we're still really beginning to understand what's going on here.
54:34And now, there's an added urgency to their work.
54:41Over the last 50 years, the Yucatan's population has skyrocketed.
54:50The city of Cancun is one of the fastest-growing tourist destinations in the world, with over
54:57five million visitors every year.
55:05This creates jobs, but the demand for fresh water is putting pressure on the peninsula's underground
55:11rivers.
55:13And the future of this area is dependent on tourism, and so how do we sustainably manage
55:19these incredible natural resources here so that Mexico can continue to receive 10 to
55:2612 percent of its gross domestic product through tourism on a hundred-mile strip of beach?
55:33That's important to the future of Mexico, not only of this region, but the country as a whole.
55:43Maps of the underground river systems are far from complete.
55:48New construction work may be taking place above caves that are yet to be discovered.
55:56The entire city of Cancun draws its drinking water from 142 cenotes,
56:03some of which are now at risk of pollution.
56:13It's a race against time to reveal the importance of the Yucatan's hidden underworld.
56:25Back at Taj Mahal, with the lights in place, the crew are ready to begin filming.
56:36Every image they film must be meticulously planned.
56:44Get over, more light, less light.
56:50Once the dive begins, all communication is through hand signals.
57:08At last, the team can capture the splendor of the hidden underworld.
57:20At last, the team can capture the splendor of the hidden underworld.
57:24It's not as accessible as it was to the ancient Maya.
57:29But for the cave divers, devoted to exploring this world, the hope is that by opening our eyes to its
57:37beauty and importance, they will help safeguard its future.
58:00In the next episode, we head to Mexico's remotest region, the far north.
58:07A land of great deserts and rich prairies, home to the toughest of characters, secret worlds, and some of Mexico's
58:22rarest wildlife.
58:33Dora and Ed take the jovial road to Mandalay via Thailand next on BBC Two.
58:38But that reigns, no laughing matter.
58:40And now, over on BBC Four, an incredible documentary exploring race, fame and the justice system in OJ Made in
58:47America.