- 2 days ago
Taking an epic journey following the descent of the planet's mightiest rivers from their mountain sources to the sea.
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01:01A labyrinth of caves, carved by fresh water.
01:17An essential for life on Earth.
01:51And the creatures that live in it.
01:55In the most surprising ways.
02:14The rainforest of Costa Rica.
02:18As you might expect, it rains most days.
02:25But it's only during the wet season that the rains become torrential.
02:39And with them comes a most remarkable creature.
03:00Gliding tree frogs.
03:10Thousands drop in.
03:15Together at this newly formed pond.
03:26They all have an urgent need.
03:35To breed.
03:37To breed.
03:50This female needs to find a leaf and lay her eggs.
04:01The breeding frenzy will only last one day.
04:06So she needs to get a move on.
04:15There are lots of eager males.
04:24Nine for every female.
04:26Nine for every female.
04:30And all are ready to spring into action.
04:40So for her, getting a partner is no problem.
04:54But the other males are desperate.
04:58But the other males are desperate.
05:17For this female, mating is rather chaotic.
05:34Things are getting out of hand.
05:45There is one way to deal with this.
05:54A few well-placed kicks usually does the job.
06:14Problem solved.
06:20She and her partner can now finally mate.
06:25In relative peace.
06:28She and her partner are desperate.
06:56She is a woman.
06:56And she is a woman.
06:56She is a woman.
06:56She is a woman.
06:57She is a woman.
06:57The eggs are positioned perfectly, directly overhanging the pond.
07:22This is the ideal nursery for tadpoles.
07:31For now, her work here is done.
07:35She'll be back next year, when the heavy rains return.
07:43As quickly as fresh water appears, it can vanish.
08:03South East Sri Lanka.
08:08It's the middle of the dry season.
08:27This is the only remaining waterhole for miles around.
08:32It's the end of the farm.
08:35I'll be back, as far as it is.
08:40It's the end of the earth.
09:02Let's go.
09:32Crocodiles. Giants five meters long.
09:40Dozens are hiding beneath the surface.
09:53And others are on their way.
10:16This male has been traveling for hours.
10:26The waterhole is the only place where he has a chance to catch a deer.
10:43A single adult would be enough to feed him for the entire dry season.
10:59But hunting prey that knows you're here requires something truly remarkable.
11:24He creates... a trap.
11:39He digs down into the mud.
11:55Deep enough to hide beneath the vegetation.
12:16Perfect camouflage.
12:30He has built his trap right on the water's edge.
12:36So it's the first place that thirsty deer will come to drink.
12:41...
12:47...
12:55...
13:14I don't know.
13:35I don't know.
14:04I don't know.
14:55I don't know.
14:56Fresh water transforms not only the lives of animals, but entire landscapes.
15:17Every year, over a trillion liters of water flow into the Kalahari desert.
15:32It has traveled a thousand miles from where it fell as rain.
15:41And on arrival, it turns the Kalahari into a vast oasis.
16:00The Okavango Delta.
16:25These waters attract millions of animals.
16:37And for some, now is the perfect time to raise a family.
16:57A lily trotter.
17:05And he is a father on duty.
17:28He has not just one, but four newly hatched chicks.
17:51They won't be able to fly for another six weeks.
17:59So, until then, he alone is their protector.
18:10Walking on water is not straightforward.
18:17So, he must show them how to be a lily trotter.
18:42The floodwaters make the perfect training ground.
19:03And in two weeks.
19:06And in two weeks, his chicks not only double in size, they grow in confidence.
19:25But this is a dangerous place to stray.
19:39He sounds the alarm, and his chicks instantly freeze.
19:46They can't yet fly to safety.
19:52But there is one thing he can do to protect them.
19:57And it's risky.
20:02Get close enough to distract.
20:06And hopefully divert the crocodile.
20:09The crocodile.
20:14The crocodile.
20:14BIRP BIRP BIRP BIRP BIRP
20:40Mission accomplished.
20:44BIRP BIRP BIRP BIRP BIRP
21:12But one chick is missing.
21:38His calls go unanswered.
22:28SIREN SIREN
22:36A little bedraggled, but alive and well.
22:46This chick just hadn't heard his call.
22:51And when danger threatens, it's always better to be safe than sorry.
23:25He's brought his chicks, all four of them, to the verge of independence.
23:45Whilst lily trotters are well adapted to life in this flooded world,
23:52these residents of the Delta are not.
24:08African painted dogs.
24:14Normally, they are remarkably successful hunters.
24:18But this pack of five hasn't eaten in days.
24:29Finding prey isn't the problem.
24:39This herd of lechery is only a few hundred meters away.
24:48But between them is deep water.
25:13And then the
25:27It's not safe to Koss here.
26:19It's not safe to Koss.
26:21It's not safe to Koss.
27:17It's not safe to Koss.
27:29It's not safe to Koss.
28:17But they do have a strategy.
28:51Back towards dry land.
28:58Now the pack can regain lost ground.
29:32It's not safe to Koss.
29:49It's not safe to Koss.
30:02The animals must always adapt to the coming and going of fresh water.
30:11But there are a few rare places, as here in Lake Malawi, where fresh water has lain for millions of
30:19years.
30:23And that has enabled life to evolve into a dazzling diversity of species.
30:37There are over a thousand different kinds of fish here, more than any other lake on earth.
30:55Competition in these waters is intense.
31:22Meet Nimbo Kumis Livingstoniae.
31:30A master of deception that tricks other fish into thinking it's dead.
31:40Its mottled coloration mimics decaying flesh.
31:51But to appear dead, one must at least act dead.
32:05This juvenile is fooling no one.
32:13Perhaps faking his death will be more believable.
32:43Blowing it.
32:55A more subtle performance will be needed.
33:11This is more convincing.
33:27But his aim must be better than that.
33:37Nearly.
33:46It seems he's overstayed his welcome.
34:07It seems he's overstayed his welcome.
34:22In a final effort, he appears to even hold his breath.
34:48Succes, at last.
35:11All it took was a million years of evolution.
35:23And the unique stability of this ancient lake.
35:37Off the western coast of Equatorial Africa lies the volcanic island of Biota.
35:55Freshwater here has a turbulent nature.
36:02The
36:02The
36:03The
36:03The
36:03The
36:03The
36:03The
36:35Few venture into such waters, but for those that do, there can be great rewards.
36:46After months feeding and growing out at sea, these gobies are ready to breed.
36:56And the safest place to lay their eggs is somewhere that ocean predators can't reach.
37:05The top of this waterfall.
37:13Surely an impossible journey for a fish.
37:21But over the coming days, the gobies transform themselves.
37:29They change color.
37:36Their mouth rotates and acts like a kind of suction cup.
37:44Which they will certainly need.
37:51Because the only way is up.
38:17It is 30 meters to the top.
38:27They are only an inch long.
38:33This is the equivalent of a human being scaling a waterfall over a mile high.
38:50Millions attempt the climb.
38:53But less than 1% will make it.
39:06This goby has been climbing for days.
39:19Made it.
39:25Those that reach the top can now prepare to breed.
39:32And when the time comes, their young will be washed back out to sea.
39:58The extraordinary power of flowing water makes it our planet's greatest architect.
40:25This may look like the surface of an alien planet.
40:42But these strange patterns are channels of fresh water.
40:51Flowing towards the sea.
41:07For 3.8 billion years.
41:10Ever since the first rains fell.
41:15Fresh water has been making this journey.
41:34But today, two-thirds of our world's great rivers no longer reach the sea.
41:41We're likely to have ourlier.
41:44Within storage.
41:47That's a very little trouble.
41:48In the small light.
41:53Pe тонれ.
41:53The city's tallest لا.
41:53Pale or ste bulk.
42:10Oops.
42:10With the sea.
42:11With the sea.
42:13There is a finite amount of fresh water on Earth.
42:30So humans have devised extraordinary means to ensure that it is always available to meet
42:38our every demand.
42:50We now control fresh water on a colossal scale.
43:01The largest irrigation system on Earth has been built here in Pakistan, a vast network
43:19of dams and canals that diverts and drains the great Indus River.
43:34It's used to irrigate an area the size of England.
43:43This man-made freshwater world provides water and a livelihood for millions of people,
43:59but at a cost to the natural world.
44:15A rare creature has become stranded in this irrigation canal.
44:25And the water will soon be gone, used to supply the surrounding land.
44:38Endangered, they number fewer than 2,000 individuals.
44:48An Indus River dolphin.
45:05This female dolphin is 150 miles from the main river.
45:14She can't return on her own, so the only option is for this rescue team to take her.
45:46out of water, she cannot survive for long.
45:56The journey back to the river will take hours.
46:00The journey back to the river will take hours.
46:09Her life now depends on these people.
46:15Her life now depends on these people.
46:32This female鮮쌤 has the size of—
46:33as the great bekommen, no death—
46:45and who forgives herself.
46:46The team has бегed to hang out by the other road.
46:46The project has been最悪.
46:57The team has been progressed.
48:05Nearly 30 dolphins had to be rescued in one month alone.
48:41Freshwater is not only a resource for humans.
48:51It is the home for countless species that simply cannot survive without it.
49:20Freshwater is the lifeblood of planet Earth.
49:48To film the story of the most endangered freshwater dolphin,
49:53the planet Earth team joined the world's leading expert, Uzma Khan.
49:58The first time I saw Indus dolphin, I was just amazed.
50:02It's a beautiful creature, you know, it's like love at first sight.
50:06It's so unique.
50:08Uzma has been studying the last remaining population for over 20 years.
50:16There's a dolphin that surfaced just right there.
50:20Indus River dolphin can only live in freshwater.
50:24It is only found in Pakistan and nowhere else,
50:27and we only have about 2,000 of them left in the Indus River.
50:31So, you know, each individual is special.
50:38Following the dolphins in the murky water is extremely challenging.
50:43They only surface for a split second, and that makes protecting them difficult too.
50:50Their greatest threat is becoming trapped in the irrigation canals.
50:57But Uzma may have a solution and teams up with a rescue unit
51:05to attempt something never done before.
51:10This is the first time we'll be putting satellite tags on river dolphins in Asia.
51:15Since this has not been tested on the species, there's a little bit of anxiety.
51:21But if they work, then it's going to be a breakthrough for conservation.
51:28Uzma has been developing a suitable tag for over 10 years.
51:33And hopes it will help her collect critical data
51:37on how the dolphins are moving through the dams and canals.
51:41But in order to tag, she will first need a successful rescue.
51:56I'm usually very concerned when a rescue is happening.
52:09You know, the divers, they are very experienced, but a part of me is always very worried.
52:18They are wild animals that have never been handled.
52:23It's really quite a risky thing that they're undertaking here.
52:26There's a good chance the dolphin might die.
52:28But of course, they're balancing that against the fact that
52:30they definitely will die if they stay in here.
52:33So it's a risk they have to take.
52:58Now, speed is key.
53:10We're now bombing across the field on the way to the release site.
53:13And I think Uzma went ahead of us.
53:15I'm really hopeful that she'll get her opportunity to tag the dolphin.
53:22But rescue missions don't always go to plan.
53:46The dolphin is quickly moved to the film crew's truck.
54:11But with no roof for shelter, the dolphin is at greater risk of dehydration.
54:28The team reroute to the closest release site.
54:35There can be no more delay.
54:38Uzma calls off the tagging.
54:59It's unfortunate because we were all prepared.
55:02We were very excited since morning, all geared up.
55:04But hopefully, we'll get an opportunity to find the next rescue.
55:20A few days later, Uzma finally gets her chance.
55:30It's a very exciting day for us.
55:34It's OK.
55:36The moment that we have been waiting for over 10 years.
55:41Just stay calm.
55:47Okay, it's good to go.
55:54Congratulations, Babarikou, well done.
56:02I am very happy, very happy, I think it's a great accomplishment.
56:10It's the happiest moment of my life.
56:20Within a few weeks, the tags begin to reveal some new insights.
56:28They are moving quite a lot, which we never expected.
56:31So, one of the dolphins actually went about 46 kilometers upstream from the release site.
56:39And the other thing is that we thought that they will stay in the main river stream, but
56:43they are using side channels.
56:45It is extremely interesting.
56:48Tracking the movement of the tag dolphins will help Uzma better understand when and where
56:54they become trapped, helping safeguard the future of this most endangered animal.
57:08Next time, forests.
57:13A hidden world where lives are intimately entwined in the most unexpected ways.
57:33Habitat Explorer brings animals and their habitats to life.
57:37Explore this free interactive and make origami animals.
57:40Go to bbc.co.uk forward slash planet Earth 3 and follow the links to the Open University.
57:47Or to order a free printed version, visit the website or call the numbers on the screen.
57:56Go to bbc.co.uk.
57:57Go to bbc.co.uk.
58:09Go to bbc.co.uk.
58:12Go to bbc.co.uk.
58:12Go to bbc.co.uk.
58:12Go to bbc.co.uk.
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58:25Transcription by CastingWords
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