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00:57With the help of a little modern technology, I've been listening to the calls of one of the great
01:02de uno de los grandes predatos de la ocean.
01:05Seguimos a dos o tres miles de aquí.
01:08Es sorprendido, son los sonidos de la humpecadera.
01:17Llegarse a la luz, es un gran grano.
01:23El herring es fácil, pero los pequeños pequeños tienen una gran weakness.
01:28They use tiny sounds to control the movements of their show, so their sense of hearing is acute.
01:37And at 180 decibels, the humpback screens are completely overpowering.
01:58This is predation on a massive scale.
02:15Very few of the herring are lucky enough to fall back into the sea unharmed.
02:28That humpback's scream as they hunt has only been discovered recently.
02:33Indeed, research is now revealing that the whales, far from being the gentle giants of popular belief, have a very aggressive side to their characters.
02:50Southeast Alaska in mid-December.
02:53Several hundred humpbacks have spent the entire summer here, cruising between the islands of the Inside Passage, feeding on the rich plankton and fish stocks.
03:13Now the chill of approaching winter heralds a change.
03:23Thousands of old squaw duck have migrated here from the polar north.
03:37Compared to the Arctic, these conditions are comparatively mild, and the ducks will spend the winter feeding in these sheltered waterways.
03:44But for most of the humpbacks, there is a pressing need to set off on an epic journey of their own, even though they are at no risk from the colour.
03:59By the end of December, the whales are heading south.
04:18Blowing for breath regularly, and travelling singly or in small groups, the humpbacks keep up a steady pace of about six miles an hour.
04:35The sound of their passage attracts a pod of Pacific white-sided dolphins.
04:40Eventually, the whales must set out into the open ocean for a voyage of three-and-a-half thousand miles.
05:01The islands of Hawaii in January.
05:10The volcanic sea cliffs here are the tallest in the world, and in the vast Pacific Ocean, they provide rare protection from the wind and swell.
05:28So this sub-tropical water is an ideal sheltered nursery in which humpbacks can raise their young.
05:35This was the reason for the great migration to breed.
05:40Hawaii is visited by about 5,000 humpbacks every winter.
05:49Several hundred of them are mothers with their calves.
05:57The maternal bond is exceptionally close.
06:01This 50-ton cow and her four-week-old calf will be inseparable for about 10 months.
06:07As he's still quite a weak swimmer, she gives him an energy-saving piggyback ride, and gently nudges him up to the surface to help him breathe.
06:18At first, some scientists thought visitors like this were females, aunts, helping out with the calves.
06:34In fact, they're males, and probably the last thing on this escort's mind was the calf's well-being.
06:41To be continued...
06:42To be continued...
06:56La Iglesia de Jesucristo de los Ángeles
07:26This trio of cow, calf and male escort is a common social group in the breeding area.
07:34But the liaison is tense because soon after giving birth, the cow is ready to mate again.
07:42The escort is almost certainly waiting for his chance.
07:50But the cow has other more pressing engagements.
07:53Her calf needs to suckle regularly and nudges in under her huge four-metre pectoral fins.
08:02For now, the male seems patient enough to wait.
08:06The lungs of baby whales are only small, so his mother has to release him regularly from the protective clasp of her fin.
08:21The adults can remain underwater for up to 40 minutes.
08:40For the calf, it's a different story.
08:47Every four or five minutes, he has to surface all by himself and gulp for air.
08:5320 metres below, the adults wait for the calf's return to the nipple.
09:0620 metres below, the adults wait for the calf's return to the nipple.
09:19Schooling mackerel also head for the immense bodies, perhaps using them as a temporary shelter in the vast expanse of the open ocean.
09:38The small group may remain together for days at a time, gently moving about between the islands.
09:52Idyllic as their setting may seem, it's vital that the calf develops in size and strength quickly.
09:57His survival may depend upon it.
09:59One month has passed.
10:23The calf is doing well, hugged protectively by his ever-vigilant mother.
10:28As before, as soon as he needs to breathe, she releases him.
10:38But trips to the surface are no longer so daunting or frequent.
10:42The calf has grown both in size and independence.
10:58A breathing expedition now is a perfect excuse for some fun.
11:05A breathing expedition now is a perfect excuse for some fun.
11:10The play is excellent for improving much-needed stamina, but the commotion may also attract the attention of other whales and people.
11:32Like scientist Jim Darling.
11:41He's been working with humpbacks for 18 years, slowly trying to discover more about their behaviour.
11:47Because if we are to conserve these great whales properly, we must know what their needs really are.
12:00Humpbacks are world famous for the beauty of their singing.
12:04But Jim's main interest is in its social function.
12:07So he uses a hydrophone to locate and listen to singers.
12:11Humpbacks are young singers.
12:13¡Suscríbete al canal!
12:43...with their pectoral fins thrust down and held stiffly outwards.
12:49All the whales sing roughly the same song,
12:52a rigidly structured pattern of themes lasting about 12 minutes,
12:56which can be repeated almost without break for hours on end.
13:13A passing whale eventually moves in to check out the singer.
13:31Is this a female, attracted by the bull's voice,
13:35or another male, assessing the strength of the competition?
13:39In any event, the singer is disturbed and quickly moves on.
13:46Sometimes the intruding whale will catch up with the singer
13:50and swim with it for a few minutes.
13:52But is this passion or war?
14:00Jim's task is to identify and sex the incoming whales
14:04to try and solve the riddle.
14:06First, he takes photos of the tail flukes.
14:18And then waits to snap the dorsal fin as well.
14:21Both are uniquely marked or shaped
14:24and will identify the animal for future reference.
14:29Ah, I think it is the one with the white tail.
14:33But sexing a whale is another matter altogether.
14:36It'll just stay along right at this distance.
14:38The best technique is to take a skin sample.
14:41Fit this way.
14:43Okay, that's good.
14:44But it's a very difficult thing to do.
14:47Just manoeuvring a boat close to a whale
14:49without disturbing it takes great skill.
14:51Okay, slow.
14:52So research assistant Karen reacts instantly to every direction.
14:56A little bit more this way.
14:58And they need to get close enough
15:00to fire a low-powered dart
15:02that collects a tiny plug of skin.
15:04Done correctly, it causes no alarm.
15:11The sample will be sent back to the laboratory for DNA analysis.
15:16All right.
15:17Good.
15:18Okay.
15:19It will reveal the whale's sex and genetic details.
15:23And Jim's preliminary results have shown
15:26that all the joining whales he's tested are male.
15:30So it seems that the song could indeed
15:32be an elaborate communication of male status.
15:36Perhaps it's war, after all.
15:42And when it comes to competing for a mate,
15:45the bulls do more than just sing.
15:47There are over 1,000 of them around Hawaii,
15:50so the competition for females is intense.
15:53Even cows with calves are fair game,
15:59and the females may actually encourage the bull's attention.
16:02For the calf, this will be a testing time.
16:12This bull with distinctive white pectoral fins is the escort,
16:16and he moves in quickly to claim his right.
16:22But the cow still heads off with her calf close beside her.
16:31And the male soon picks up the chase.
16:34The escorted group changes course.
16:56Perhaps the bull is trying to shake off the pursuers.
16:59But following them is easy.
17:06The escort tries a threat display
17:08by blowing jets of bubbles underwater.
17:10Perhaps it helps establish a dominance pecking order
17:29in the queue following the cow.
17:31Another bull moves closer.
17:46Another bull moves closer.
18:01Blowing like a surfacing submarine,
18:03the escort moves in to intercept.
18:07The female lifts her head clear of the water.
18:16After swimming at 10 miles an hour for some minutes,
18:19the calf is tiring and flails in distress.
18:27The bulls are overhauling them.
18:31As yet another male powers up from behind,
18:51the cow finally stops,
18:53slapping her flipper loudly.
18:55With balls circling her continuously,
19:05she starts tail-slashing,
19:08perhaps to fend off the less desirable mates.
19:15And in another attempted display of dominance,
19:19the escort moves towards her
19:21with his fins held stiffly outstretched.
19:23Undeterred, up to seven males circle the cow,
19:31totally surrounding her.
19:33They hoot as they manoeuvre for prime position.
19:43The competition becomes yet more intense
19:46as one of the bulls chases the escort away.
19:48Now the cow is an unprotected target.
20:07During the ensuing confusion,
20:08it's possible that she will be finally mated.
20:11It's possible that she has a pig.
20:30Thrashing weakly, the calf by now is close to exhaustion.
20:35So, his mother glides up to reassure him
20:40and, if necessary, give physical support.
20:48But for the moment, they are ignored.
20:51The bulls are too engrossed in a conflict
20:53where collisions may even draw blood.
21:01By now, the cow has probably mated successfully,
21:04so she takes the chance to slip away, and not before time.
21:09Her calf desperately needs to suckle.
21:12If these chases happen too often,
21:15it's possible that the stress and lack of feeding
21:17could be fatal to calves.
21:29By February, Jim's team is joined
21:31by the renowned underwater stills photographer,
21:34Flip Nicklin.
21:36The two have worked together, on and off, for over 18 years,
21:40and they're quickly amongst the whales.
21:52Suddenly, they notice something strange about one of them.
21:55It dives with a lopsided tail.
22:02It's a style that's reminiscent of a whale
22:05that was a major landmark in their research,
22:08and they last saw him 18 years ago.
22:16They approach with a real sense of growing excitement.
22:19Could it be the same whale?
22:20Could it be the same whale?
22:29This is a unique opportunity.
22:3618 years ago, Flip and his father Chuck
22:39became the first people to dive down to a singing whale.
22:43Their breakthrough was to hold their breath
22:59instead of using scuba gear with its noisy bubbles,
23:02and the photos they took were the first proof
23:05that singers are male.
23:10Diving this close to a singing whale
23:13is an extraordinary experience.
23:15Its voice is so strong
23:17that the whole of Flip's body
23:19is physically vibrated.
23:26He's searching for identifying marks
23:29in the whale's tail,
23:30because Frank had a big, ragged tear
23:33in his left fluke
23:34with deep lacerations from a cable entanglement.
23:45Amazingly, after all this time,
23:47Flip was indeed looking at the very same tail.
23:51It was Frank.
23:58Unable to hold his breath any longer,
24:00Flip is forced to head for the surface.
24:06Remarkable, though, Frank's rediscovery was,
24:08it also revealed just how little we know about these animals.
24:12Where had he been during all this time?
24:17It's possible that he had visited Hawaii every year
24:21and had simply not been seen.
24:27But there are other Hawaiian humpbacks
24:29that have been spotted in breeding grounds off Japan
24:32and islands near to Mexico's Pacific coast.
24:38It appears that they are all part of the same population,
24:41sharing similar songs
24:43and wandering as they please.
24:50But there are humpback song cultures in the Pacific
24:53that Frank is unlikely ever to meet.
24:56February, on the edge of the Antarctic ice shelf.
25:05The Northern Hemisphere is still in midwinter,
25:08but down here it's high summer
25:09and humpbacks visit annually to harvest the rich pickings.
25:14This is an entirely different group of whales
25:16to those in Hawaii.
25:17All too soon, severe cold will drive them north
25:24to breeding grounds of their own.
25:26But they remain south of the equator,
25:28amongst the South Pacific islands of Fiji and Tonga.
25:31There are only about 100 humpbacks around Tonga
25:39because, until recently, they were hunted.
25:43And it's the first time
25:44that Flip Nicklin's father, Chuck,
25:46has visited these islands.
25:48So he's far from certain of finding whales.
25:54But after a week of waiting,
25:57he's finally spotted some activity
25:59and sets off to investigate.
26:09He approaches as quietly as he can.
26:21His luck holds.
26:23This is the first time he's ever seen a Tongan whale.
26:26And it's a mother and a calf.
26:29Edging closer reveals that the calf is very young.
26:33The crease on its side
26:34is from being curled up inside its mother's womb.
26:37And remarkably, it's almost pure white.
26:45In fact, southern whales are quite different
26:47in appearance from those of the north,
26:49and even the adults have far more white markings.
26:52Although Chuck has been diving with whales for 30 years,
27:00swimming this close is still a huge thrill.
27:03And the cow and her calf seem totally unconcerned.
27:06Perhaps there are so few bulls here
27:08that there isn't as much sexual harassment as in Hawaii.
27:12So the cow is more tolerant.
27:13But there are some males here.
27:21The song is very different to those of the northern Pacific,
27:38with extraordinary chirps and screams.
27:41This singer's action is also quite different.
27:44Even whilst it rolls and plays,
27:47the song keeps booming out.
27:50It seems a much more light-hearted performance,
27:52and it's easier to make an approach.
27:54Although they can cross the tropics,
28:23southern whales are governed by the seasons of the south.
28:26So they breed six months later than the northern Pacific humpbacks,
28:30and they must also head south to feed.
28:36This male's song will probably never be heard north of the equator,
28:41and will always sound quite different.
28:43He's from a distinct population with its very own language.
28:47Researching the movements and cultures of Wales on a global scale
28:54is incredibly difficult.
28:56How on earth can you follow a migrant across thousands of miles?
28:59One man who does just that is Professor Bruce Mate.
29:14He's using high-tech telecommunications
29:17to track some of the Hawaiian whales on their northbound migration.
29:21A satellite transmits positioning signals from tagged animals,
29:31revealing their precise location day or night.
29:34The results are already extraordinary.
29:37Hawaiian humpbacks don't have one single destination.
29:41They radiate out to feeding areas all over the North Pacific.
29:44This group is nearing the coast of southeast Alaska.
29:57The rugged coastline is fringed by hundreds of mountainous islands,
30:02and the cold water that separates them
30:04is some of the most productive in the world.
30:07At the end of their long journey,
30:09the whales seem almost exuberant.
30:11They breach and slap their flippers repeatedly.
30:29It's a phenomenal display.
30:31It takes enormous strength to hurl a 50-ton body out of the water.
30:36The strong tidal rips that run here literally seethe with fish.
31:03Countless millions of herring cruise near the surface,
31:13sipping individual plankton from the dense summer bloom.
31:18But catching plankton can be a risky business.
31:22Herring is a favourite on Alaska's coastal menu.
31:26The shoal bunches into a protective ball,
31:33but it's little defence against diving guillemots and auclots.
31:45From above, young herring gulls add to the feeding frenzy,
31:48and the commotion attracts a dogfish.
31:51Before long, there are extraordinary numbers of these small sharks
32:08on the prowl for herring.
32:13But to try and escape, the shoal has dived deep.
32:16Depth is no guarantee of safety.
32:27A wall of bubbles rises up to the surface, expanding noisily.
32:32The line keeps growing until it becomes a complete ring.
32:44Corralled by the vertical net of bubbles,
32:47the herring are trapped at the surface.
32:52It's the worst place to be.
32:54The lone humpback lunges into the centre of his bubble net.
33:07The whale can repeat this attack every few minutes, for hours on end.
33:11The spread of its jaws is over four metres,
33:25and pleats in the whale's throat stretch enormously along half its body length,
33:30allowing it to engulf hundreds of gallons of water.
33:35A single gulp can devour an entire shoal.
33:41There are noanding eyes.
34:01Rich feeding like this attracts dozens of whales, often in large groups,
34:06y no es conocida de la estructura social de los grupos o de sus movimientos.
34:13Bruce Mate es keen a usar sus técnicas de sattelar para descubrir más sobre el comportamiento de la vida en las áreas de la alimentación.
34:20Bruce Mate believes that knowing where the most important humpback feeding areas are and how the whales utilize them will help us to ensure that the right protection is given both to their environment and the whales themselves.
34:51But first, he must tag some whales.
34:57His team uses a manoeuvrable boat for close approaches.
35:01They must be close enough to dart the whales with a small satellite transmitter.
35:11Barb, the skipper, has to time her runs perfectly to get Bruce into exactly the right position at the right time.
35:20If, at the last split second, the whale surfaces in slightly the wrong place, they abort the pass.
35:28It's an enormously skilled and tense operation.
35:35Safety off.
35:36Let it come up again.
35:43Let it come up again.
35:45If it will.
35:46OK, go, go, go, go, go, go, go, go.
35:51Yes!
35:53Woo-hoo!
35:54Yes, indeed.
35:55All right.
35:57Watch your hands now.
36:00All right.
36:01Yes!
36:03Very good.
36:04After retrieving the dart sleeve with a thin line, Bruce and his crew will take photos of the tagged whales for reference.
36:10They're still far from certain that a tag will work.
36:27A satellite has to be able to pick up its signals.
36:29Even with a satellite in the right position, the system will only operate if a tagged whale comes to the surface, the blow.
36:48And even then, if the transmitter is angled incorrectly, they won't receive a signal.
36:52To find out if everything is working, Bruce needs to get to a phone.
37:12It's kind of exciting.
37:14A week now.
37:16First time.
37:17We're connected.
37:29We've got data.
37:30Come on over and take a look.
37:31Great.
37:32All right.
37:33This is neat.
37:34Look at this.
37:35All this stuff.
37:36Oh, that's amazing.
37:37843.
37:38This is just the last?
37:39That's the first one we tagged.
37:40Yeah.
37:41On the second.
37:42Right.
37:43Wow.
37:44Can't tell you.
37:45Still scrolling by.
37:46We've got so much.
37:47We've got so much.
37:48Oh, my God.
37:49Look at how many messages.
37:508 messages in one orbit.
37:51Right.
37:52Yeah.
37:53And it's just the start.
37:54You know, with everything going well, we're going to have data coming in for a long time.
37:57That is so great.
38:02Their excitement is justified.
38:04Data from the summer tagging has shown that the whale groups are flexible.
38:09The numbers and individuals change constantly.
38:12They've even found that the animals move around, seeking out the best food hotspots.
38:19But if the fishing is good, they'll stay in one area for weeks at a time.
38:27And dense fish stocks attract more than just whales.
38:31Hurst saying boats use a mechanical version of the humpback's bubble netting technique.
39:01Often, whales and fishermen will work in the same area, sometimes even for the same catch.
39:08But by June, the fishing boats are not allowed to land herring.
39:13They're working the summer salmon run instead.
39:22But salmon eat herring and plankton, so the whales may still find a catch alongside the boats.
39:32Once the fishermen have located a shoal on the echo sounder,
39:36they run the net out with a powerful launch,
39:39eventually making a complete circle and enclosing their targeted shoal.
39:50The base of the net is closed and the fish pulled up to the boat.
40:01By contrast, whales use the surface as the final trap for their catch.
40:23When the whales are close by, great care is needed to ensure that one doesn't get caught up in the net.
40:31As soon as an area is cleaned out or the prey move on, the humpbacks, like fishermen, move on as well.
40:58Cruising the island channels in search of fresh herring shoals.
41:05When a new shoal is located, it may be deep or dispersed.
41:10Scientists have known about bubble netting for years,
41:13but they've only recently discovered the whale's ultimate weapon
41:16for destroying the fish shoal's coordination and for herding the catch.
41:20The scream.
41:21The scream.
41:22The scream.
41:23The scream.
41:25The scream.
41:26The scream.
41:27The roar.
41:28The roar.
41:29The roar.
41:30Thevsug the rightétait the worst man- world in the east.
41:31Is it too, too?
41:32It's too info in the east, and in some gates?
41:34This is because of the travelari deck and the family's领向.
41:35This is a revolutionary hunting for others.
41:36Is it a tertiary сразу to the fox?
41:37For fishing.
41:38The roar.
41:39¡Suscríbete al canal!
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44:09¡Suscríbete al canal!
44:39¡Suscríbete al canal!
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