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00:00¡Gracias!
00:30¡Gracias!
01:00Crocodiles hail from the great age of reptiles well over 70 million years ago.
01:09Since then, the world has changed dramatically around them, but amazingly, they have changed
01:16little.
01:17They're the only great reptile predator to have outlived the dinosaurs.
01:27Ancient they may be, but 70 million years on, they're still the most successful freshwater
01:37predator.
01:38Most of the waterways in the tropics these days have their own species of crocodile.
01:44How come that they've been so successful for so long?
01:47Well, it seems that their design when it first appeared was already very advanced, and it's
01:52kept them successful ever since.
01:55This film reveals the nature of that success.
02:05Crocodiles may have scored an early evolutionary bullseye, but there's much more to their staying
02:15power than brute strength.
02:22Only now, by exploring their complete world, above and below water, by day and night, can
02:41be fully appreciate just how sophisticated they are.
02:48Underwater crocodiles have perfect poise.
02:49They can control their buoyancy like a submarine.
02:55To dive, they just breathe out, which reduces their lung volume.
03:02They can sink without trace.
03:03They can sink without trace.
03:09While submerged, they're protected.
03:10Underwater crocodiles have perfect poise.
03:12Underwater crocodiles have perfect poise.
03:13They can control their buoyancy like a submarine.
03:16They can control their buoyancy like a submarine.
03:17They can control their buoyancy like a submarine.
03:18To dive, they just breathe out, which reduces their lung volume.
03:23They can sink without trace.
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04:28Even Tyrannosaurus rex couldn't match this winning formula.
04:35It's a design that has allowed them to spread around the tropical world.
04:41This extended family includes alligators of temperate waterways,
04:46garils of the Indian subcontinent,
04:51and caiman of tropical South America.
04:54They've even invaded the sea.
05:08Crocodiles have special glands which enable them to tolerate salt water.
05:13This is how they've colonized new rivers along the coast.
05:16But only a few species can migrate across oceans.
05:31The real specialists, the saltwater crocodiles,
05:35are affectionately known as salties.
05:37They've been seen 1,000 kilometers from land,
05:41encrusted with barnacles as they search for new island homes.
05:47This pioneering spirit and their unique character
05:51has made them a universal threat.
05:54Crocodiles deserve their tough reputation,
06:18but they aren't just solitary killers.
06:21In the calm of the Florida swamps,
06:23we can begin to see them in a new light.
06:26They are reptiles with social skills,
06:39and American alligators are particularly chatty.
06:43During the breeding season,
06:44an expressive chorus of bellows, grunts and hisses
06:48rises from their densely vegetated swamps.
06:56The males are calling to distant females,
07:01but their bellows sometimes attract rivals.
07:13There are snappy ways to make your feelings known
07:17if you end up in the wrong company.
07:19The resident male only shows a bit of muscle
07:26if the rival fails to get the message.
07:29He's made his point,
07:47and he can now focus on finding a mate.
07:59Vibrations within his muscle walls
08:01send sound waves rippling out into the swamp,
08:04powerful enough to make the water dance.
08:29Part of his roar radiates at such low frequency
08:37that human ears can't hear it.
08:40But these subsonic calls have astounding penetration,
08:44travelling four times faster and further under the water.
08:50Only with special low-frequency recordings
08:53can we appreciate what the female alligator hears.
08:56She finds his romantic rumblings irresistible.
09:11They actually wereteifying and he went about to be squirteen.
09:14An un appointment ryken of bodies
09:15or horizontal pfont.
09:16Just a little boy who fell through the ground,
09:17but he may know it was deserves to be our admspection to him.
09:18But he turns to be hygienему.
09:19And a Deaf guy ended up in the inside for hands.
09:20Oh, he w garment is a small ass,
09:21a young man got too close to a few Rossai
09:23in some big spaces for densely meters.
09:29One of the two suits first is to have been
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10:50Crocodiles are extremely sensitive to touch.
10:54Their armor-plated toughness would appear to be only skin deep.
10:57Such complicated language and behavior is exceptional among today's reptiles.
11:10But crocodiles might provide a tantalizing rear window on the social life of their ancient relatives, the dinosaurs.
11:18Nile crocodiles are the most fraternal crocs of all.
11:26Once a year, they hang out together, soaking up the sun at traditional mating places.
11:31These are far from being lazy afternoons.
11:37The group is very organized, so individuals keep a careful eye on movements within it.
11:43An adult male, over five meters long, the center of attention.
11:49Up to ten females spend much of their time in the water soliciting him.
12:05They bear their throats as a gesture of appeasement.
12:14Body signals are also used by the male.
12:17He shows off with noisy water displays.
12:20These postures enhance his attractiveness to females.
12:39It's they who often take the lead, by rubbing themselves along the length of his body.
13:09At first, he snubs both of them, but the rubbing releases a pungent oil from glands under their jaws.
13:19Both sexes are highly sensitive to this crocodile perfume, and the male answers with his own musky message.
13:27The scent in the water is particularly potent prior to mating.
13:57Several weeks later, the females are ready to make their nests.
14:19Even when basking, adults rarely move far from water.
14:23So it's ironic that the first and most critical part of the crocodilian life is spent on land.
14:34Crocodile babies are born encased in eggs, but they must still breathe air.
14:39It's essential that this mother lays her clutch well beyond the high watermark.
14:53The eggs will be so at risk from drowning, from predators, and from temperature fluctuations,
15:02that she relies on exactly the same nest position year after year.
15:07These time-honored sites are a measure of the experienced care that crocodile mothers provide.
15:13Once the excavation is complete, she lays her eggs in a trance-like state.
15:25She's entering a deep commitment to her offspring.
15:28The hole will become an incubator.
15:49Crocodile eggs will only develop if they remain between a steamy 27 and 34 degrees.
15:55So her choice of site is critical.
16:08Nest chambers from equatorial African plains to high Himalayan river valleys
16:14all remain within this temperature range.
16:17But no one knows how crocodile mothers get it right.
16:20Crocodile mothers get it right.
16:20Crocodile mothers get it right.
16:22Crocodile mothers get it right.
16:24Crocodile mothers get it right.
16:25Crocodile mothers are safe.
16:28Crocodile mothers get it right.
16:31Once the nest is sealed, the mothers keep vigil for 90 days.
16:44Temperature determines the sex of the developing eggs.
16:49A half degree difference between the top and bottom of the nest
16:52puede afectar el ratio de los hombres a los hombres.
16:56Según los cambios climáticos que el mundo ha experimentado,
16:59parece increíble que los crímenes han superado en todo.
17:03Los crímenes han superado en su vida.
17:06La mayoría de jóvenes y mujeres se encuentran.
17:09Los rímenes han superado.
17:11Los crímenes han superado.
17:14Los crímenes han superado.
17:17Los crímenes han superado.
17:19En general, muchos hombres y mujeres han superado.
17:22Pero estos baby nile crocs face más immediate threats.
17:26Las rímenes han superado.
17:28Los raímenes han superado a sufrir y sufrir.
17:32Hopefully their mother will hear their calls and reach the nest first.
18:02Once she digs them out, they must reach the relative security of water as quickly as
18:11possible.
18:21The babies could probably find their own way, but they're only safe if they all stick together.
18:27So their mother transports them to water herself, in her mouth.
18:43The skin of her lower jaw stretches into a hanging cradle, in which she can carry fifteen
18:48or so at a time.
18:53That's a snug fit, once you're in.
19:00Her forty or so eggs hatch simultaneously, so she'll have to make several trips.
19:12The clamourings of the waiting hatchlings constantly remind her to return to the nest.
19:19And ensure that no one misses the last bus.
19:26And ensure that no one misses the last bus.
19:33And ensure that no one misses the last bus.
19:40She releases them into a nursery pool where they must make the most of her tender loving care.
19:47They have only a few weeks under her watchful eye.
19:54For safety's sake, they call to each other, and to her.
20:01Conversations which continue into adulthood.
20:08The eighteen different sounds they'll use represent a vocabulary more typical of mammals than of reptiles.
20:15Unlike mammals, their rate of growth is affected by temperature.
20:22The warmer it is, the quicker the food digests into body bulk.
20:29Over a lifetime under a tropical sun, they may grow four thousand times bigger than this.
20:44Their mother won't eat at all.
21:05She's protecting her infants from being eaten, even by other crocodiles.
21:12So on!
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24:26Los animales pueden ser dejados high, si no exactamente dry.
24:46Finalmente, algunos de estos pasos se desvieron completamente,
24:50dejando muchos cámen expulsos y deshidratados.
24:56Temporary skin relief is provided by this ultimate of face packs.
25:03Mud is an effective crocodilian sunscreen.
25:12Cooling water is at a premium.
25:15The remaining pools are becoming overcrowded.
25:21At such pressing times, the adults usually rub along.
25:25However, babies could be eaten by them,
25:28so this is no place for a mother to raise her young.
25:37Fortunately, her babies can expect complete maternal attention
25:40during this five-month period of danger.
25:43The shrinking watercourse becomes increasingly hazardous for the babies.
25:57Drastic measures are called for.
26:08Night-time cameras reveal that they will make a run for it under the cover of dark.
26:13That escape will be risky, for it's made over land.
26:24Mother leads the way.
26:26It's a while before the babies have the courage to join her.
26:40It's a while before the babies have the courage to join her.
26:41Cawls of reassurance, and maybe her musky smell,
26:59encourage the hatchlings out of the water.
27:02Calls of reassurance and maybe her musky smell encourage the hatchlings out of the water.
27:32She follows good instincts.
27:37Night-time temperatures are less dangerous to tiny, cold-blooded bodies, and there are fewer threats about.
27:43But this is a long march that must be concluded by daybreak.
28:02Their mother's acute sense of smell brings them to their watery destination, with less than an hour to spare.
28:32There's plenty of water here for her babies to survive the rest of the dry season.
29:02But lots of other female caiman have had the same idea, and there's only room for one adult.
29:09The mothers must fight, or, as is more often the case, they simply leave.
29:17Their offspring are far from abandoned.
29:20The remaining female will adopt and protect them all, over 100 of them.
29:25This super mum carries her burden lightly.
29:40Family life may be unconventional, but crocodiles do grow up in company.
29:47As hunting adults, this may prepare them for dedicated teamwork.
30:01Especially if there's a rare dish on the menu.
30:05Migrating zebra cross the Mara River in Kenya on only a few occasions each year.
30:18Resident Nile crocodiles cannot afford to miss these fleeting chances, so they cooperate.
30:25From different places under the river banks, they spend days waiting and watching the nervous herds.
30:35With their own 40s, they don't have to wear them for dia.
30:36They spend months at a time, so they will not prepare themselves.
30:41They will be worried about their existing fleeting chances, and in a few hours they are workers from their own.
30:47I want to warn them about their differences.
30:50There's a few circumstances.
31:04Only when the zebra have committed themselves to a departure point
31:08do the crocodiles take up their final positions.
31:22The current drags the zebra downstream,
31:25so five or six crocodiles cover the crossing from different angles.
31:34It's hard work for crocodiles too,
31:37but they can submerge,
31:39taking advantage of deeper, slower colors, to move closer.
31:56Their approach is stealthy, measured and tactical,
32:00as if moving in on a chosen victim.
32:05So,
32:15it's all right.
32:17It's got to see,
32:19as we know that we can fly,
32:21a little bit more.
32:23If this Peggy's Antwerp,
32:26you can't watch a receiver.
32:28It's still not too big.
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34:00A lot of effort results in little success for the crocodiles, but only until smaller, more vulnerable animals enter the water.
34:15At any time, the zebras can be ambushed by frightening power.
34:23And lightning speed.
34:33The bayberry zebra faces several waves of attack.
34:42This is the advantage of teamwork.
35:07Most of the year, life along Africa's rivers is even more of a struggle.
35:24The dry season in Zambia's Luangua valley can be unsparing.
35:35Even vegetarians are forced to scavenge.
35:54But crocodiles still thrive on the edge.
36:02But crocodiles still thrive on the edge.
36:15Far from being dependent on large mammals such as wildebeest or zebra, crocodiles have extraordinarily adaptable diets.
36:35We've not known this until now because we've never seen them hunting at night.
36:46What crocodiles do at night has remained a mystery because they will only move around naturally in total darkness.
36:53So only with the use of invisible infrared light can we see their nocturnal habits for the first time.
37:00In the Luangua river shallows, a Nile crocodile hunts for less glamorous prey.
37:09It's stalking fish.
37:11It's stalking the white people.
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38:04The crocodile is a flexible feeder in its methods, too.
38:17It uses its armor-plated body as sinuously as a length of fishing net to corral fish towards the shore.
38:34Within their element, crocodiles equally deserve the title King of the Beasts.
39:02Only when the dry season becomes desperate are these two great hunters of land and water
39:26likely to come face to face.
39:28But only the crocodile is bold enough to leave the safety of water and meet the lion on its home ground.
39:50The lion is also determined.
39:52The lion is a dyslexic nature of the sea.
39:53The lion is ordered to be the lion's hand.
39:55The lion is a truly powerful creature that is in the sea.
39:59So, you can see it's in the sea.
40:00The lion is in the sea.
40:03The lion is wonderful, and there's a sea.
40:04The lion is so sireny and there's a sea.
40:06The lion is so sireny and a sea.
40:09The lion is a average of four miles of 14 miles and a half miles of 150 miles.
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42:11The lions are forced to defend their meal by moving to a different table.
42:19They leave nothing but scraps behind.
42:41The reptiles have stronger stomachs than the mammals.
42:47Lions can only cope with the chewy parts.
42:50Crocodile digestive juices are so acidic that they can break down skin, bone, and horn to be turned into muscle.
42:59There's no such thing as crocodile leftovers.
43:06Their exceptional sense of smell enables them to capitalize quickly on the demise of others.
43:09Their exceptional sense of smell enables them to capitalize quickly on the demise of others.
43:20And at the end of the dry season, the smell of death is everywhere.
43:25A mother hippo mourns her baby.
43:34Crocodiles have good reason to be wary of adult hippos, so they wait for the grieving mother to go.
43:43Food, any food, is hard to find.
44:00Crocodiles from up to seven kilometers away recognize the whiff of opportunity.
44:06One dead hippo attracts over 100 hungry crocodiles, but there's no feeding frenzy.
44:27This is crocodile queuing.
44:42The reason for this patient approach?
44:45Crocodiles have a powerful grip and sharp teeth, but their jaws don't move sideways.
44:52They can't chew.
44:56So they have to eat large animals together.
44:59One or two crocodiles effectively brace the carcass in their jaws, while others wrench off smaller pieces of flesh by spinning their bodies around.
45:16Everyone waits their turn.
45:25Don't turn around.
45:27One or two AfD.
45:28One-hung.
45:29One-hung.
45:30One-hung.
45:31One-hung.
45:35One-hung.
45:38Over 4X kurzit.
45:39With such tolerant table manners, it might take 24 hours to satisfy the whole queue of diners.
45:49No, no, no, no.
46:19No, no, no, no.
46:49No, no, no, no.
47:19No, no, no.
47:49No, no, no.
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