0:00:02 > 0:00:05This is Deadly 360,
0:00:05 > 0:00:07the show that pits three of the world's
0:00:07 > 0:00:09deadliest predators against their prey.
0:00:10 > 0:00:12Examining their hunting strategies
0:00:12 > 0:00:16and their escape tactics from every angle.
0:00:18 > 0:00:20By delving beneath the fur and the feathers,
0:00:20 > 0:00:23we find out why a hunt succeeds
0:00:23 > 0:00:26and why they sometimes fail.
0:00:26 > 0:00:28'One thing is certain,
0:00:28 > 0:00:31'prey animals are anything but sitting ducks.'
0:00:31 > 0:00:34Their defensive strategies keep them alive
0:00:36 > 0:00:39and push predators to the limits.
0:00:40 > 0:00:43Prepare for Deadly 360.
0:00:44 > 0:00:48This is Deadly 360 mission control,
0:00:48 > 0:00:51where all of today's action and analysis takes place.
0:00:53 > 0:00:55'We have access to the most enthralling hunts
0:00:55 > 0:00:59'that have ever been caught on camera.'
0:00:59 > 0:01:01I have recreated three of the most exciting
0:01:01 > 0:01:03and analysed them from a variety
0:01:03 > 0:01:08of angles and perspectives, in true 360 degree style.
0:01:08 > 0:01:10The predators we are looking at
0:01:10 > 0:01:12have to find and catch food or they just won't make it.
0:01:12 > 0:01:14In the wild world,
0:01:14 > 0:01:17simply managing to survive is the greatest challenge of all.
0:01:17 > 0:01:20I present to you the whales and dolphins.
0:01:20 > 0:01:24'In today's leaping line-up is the killer whale.
0:01:24 > 0:01:28'Endurance, stamina and power that is world-beating.
0:01:29 > 0:01:34'We also meet the humpback, a monster whale that hunts on a massive scale.
0:01:34 > 0:01:37'And in the open seas of East Africa, the dolphin,
0:01:37 > 0:01:38'who uses sonar to track down prey.
0:01:38 > 0:01:43'Three predators, three hunting strategies, all deadly.'
0:01:45 > 0:01:48They look invincible, but there is a continual arms race going on
0:01:48 > 0:01:51in nature, which ensures that prey animals
0:01:51 > 0:01:56are always evolving spectacular ways of taking care of themselves.
0:01:56 > 0:01:58'Today's line-up of defenders include the sardine,
0:01:58 > 0:02:03'an agile fish, with quite a turn of speed.
0:02:03 > 0:02:08'And this aquatic acrobat, the sea lion - a true master in the water.
0:02:08 > 0:02:10'Along the North American coast,
0:02:10 > 0:02:14'we investigate the herring's tactics for survival.
0:02:14 > 0:02:17'Three prey with three very different escape strategies
0:02:17 > 0:02:20'to evade even the most persistent of killers.'
0:02:21 > 0:02:25I have introduced you to all of our contenders.
0:02:25 > 0:02:28Now it is time to meet our first deadly duo going head to head.
0:02:30 > 0:02:33'We start with the dolphin. Playful, elegant mammals,
0:02:33 > 0:02:35'but also ruthless ocean predators.'
0:02:37 > 0:02:39Up against it is this.
0:02:40 > 0:02:43'The slippery sardine. They are small, quick and agile
0:02:43 > 0:02:47'and are equipped with some pretty clever tactics for survival.'
0:02:47 > 0:02:51Which animal has the edge in the race for life?
0:02:51 > 0:02:53It is time to go Deadly 360.
0:02:59 > 0:03:02'As we join the action, dolphins are circling the shoal.
0:03:02 > 0:03:04'The sardines stick together for safety,
0:03:04 > 0:03:06'twisting, to cause confusion.
0:03:06 > 0:03:10'The lead dolphin makes a move. Now the sardines are in trouble.'
0:03:11 > 0:03:14But even in a hunt like this, there are still lots of factors in play.
0:03:14 > 0:03:17To find out why a predator might succeed or fail,
0:03:17 > 0:03:19we need to wind back the action
0:03:19 > 0:03:24and build up the entire hunt right from the beginning.
0:03:24 > 0:03:27'The first thing to show you is where in the world this takes place.
0:03:27 > 0:03:29'What you are about to see
0:03:29 > 0:03:32'happened in the shallow waters of the Indian Ocean,
0:03:32 > 0:03:34'off the East Coast of Africa.
0:03:36 > 0:03:39'It is June and thousands of sardines have made their annual migration
0:03:39 > 0:03:41'up from the south.
0:03:41 > 0:03:44'Brought here by the cold currents, they come to feed on the vast blooms
0:03:44 > 0:03:47'of plankton, and where the sardines go for food,
0:03:47 > 0:03:49'dolphins will follow.
0:03:49 > 0:03:52'Dolphins follow schools of fish from place to place.
0:03:52 > 0:03:55'When the ocean is this big, it needs to use all of its skills
0:03:55 > 0:03:58'of hunting to find and catch them.'
0:03:58 > 0:04:00So, that is the scene set.
0:04:00 > 0:04:03Let us have a look at some of our predator's attributes.
0:04:03 > 0:04:07'Dolphins are solely predatory and intelligent, efficient killers.
0:04:10 > 0:04:11'They are incredibly brainy,
0:04:11 > 0:04:15'using sophisticated sonar and teamwork to succeed.
0:04:15 > 0:04:16'Add to this their speed
0:04:16 > 0:04:20'and you have one of the finest fish-finders in the ocean.'
0:04:21 > 0:04:25Those are the weapons our predator will be unleashing on its target.
0:04:25 > 0:04:27What about the animal in the firing line?
0:04:27 > 0:04:30What has it got to protect itself?
0:04:31 > 0:04:34'Well, sardines have the edge over predators in their sheer numbers.
0:04:34 > 0:04:37'These synchronised swimmers stick together for safety.
0:04:38 > 0:04:42'Sardines also have acute hearing which will alert them to predators
0:04:42 > 0:04:44'and they are also nifty little fish,
0:04:44 > 0:04:48'capable of covering ten body lengths in just one second.
0:04:48 > 0:04:51'That is like me covering 18 metres in the blink of an eye.'
0:04:52 > 0:04:55So, our predator is going to find it pretty difficult
0:04:55 > 0:04:57to get anywhere near this prey.
0:04:57 > 0:04:58Let's see what happens.
0:04:58 > 0:05:02'We join the hunt at mid-morning and the sardines have headed
0:05:02 > 0:05:07'out of deep water into the shallows, in search of plankton.
0:05:07 > 0:05:10'There is no sign of the pod of dolphins yet.
0:05:10 > 0:05:13'They are swimming up the coast.'
0:05:13 > 0:05:16But how are they going to find their food in this vast,
0:05:16 > 0:05:18and often empty, ocean?
0:05:18 > 0:05:20Well, they use sound.
0:05:20 > 0:05:24They can actually track down their prey using sonar.
0:05:24 > 0:05:25Let's find out how.
0:05:26 > 0:05:29Dolphins are extremely vocal creatures.
0:05:29 > 0:05:33They create a whole range of chirps and whistles to communicate
0:05:33 > 0:05:38with each other, but they also have one other very special kind of sound.
0:05:38 > 0:05:41A structure beneath the blowhole can create a series of clicks,
0:05:41 > 0:05:47some of which we can hear and some of which are too high for human ears.
0:05:47 > 0:05:49Perhaps as many as 1,000 of these a second.
0:05:49 > 0:05:51These are directed off into the water
0:05:51 > 0:05:55and will bounce back off any objects that are in front of the dolphin.
0:05:55 > 0:05:58They are then interpreted inside the head, so the dolphin can build up
0:05:58 > 0:06:02a three-dimensional picture of the world around it, just using sound.
0:06:02 > 0:06:05Let's see how our dolphins get on.
0:06:07 > 0:06:09'Back to the hunt.
0:06:09 > 0:06:13'The pod of dolphins have locked into the sardines and are in hot pursuit.
0:06:13 > 0:06:18'They are beautiful swimmers, moving at speed with total ease.'
0:06:18 > 0:06:22Any animal swimming through the water has to battle against
0:06:22 > 0:06:24two different types of drag.
0:06:24 > 0:06:28First, pressure drag, which is caused as it forces itself forward.
0:06:28 > 0:06:32Secondly, there is the drag of water across its skin.
0:06:32 > 0:06:34Dolphins get around this by having a slick, rubber-like skin,
0:06:34 > 0:06:37which sheds water with ease,
0:06:37 > 0:06:39allowing them to get up to speeds of around 25 mph,
0:06:39 > 0:06:41which is as fast as a speedboat.
0:06:42 > 0:06:44'But just down the coast,
0:06:44 > 0:06:47'the sardines have detected the dolphin's approach in the water.
0:06:48 > 0:06:51'Sardines have excellent hearing.
0:06:51 > 0:06:55'Sound travels further and faster in water than it does in air -
0:06:55 > 0:06:58'about four-and-a-half times faster.
0:06:58 > 0:07:01'So fish can pick up the tiniest vibrations in the water.
0:07:01 > 0:07:04'But their hearing won't help them now.
0:07:04 > 0:07:08'Their best defence tactic is to rely on their speed and teamwork.'
0:07:09 > 0:07:13Proportionately, fish have much more of their body
0:07:13 > 0:07:15given over to muscle than mammals, like dolphins, do.
0:07:15 > 0:07:20'Almost all of that muscle is purely used for swimming.
0:07:20 > 0:07:23'In the case of the sardine, that is often fast,
0:07:23 > 0:07:25'explosive bursts of speed.
0:07:25 > 0:07:29'This comes in handy when you need to move quickly as a group.
0:07:29 > 0:07:31'This is called shoaling.'
0:07:32 > 0:07:36So why is shoaling such an effective defence against predators?
0:07:36 > 0:07:41Well, let's have a look inside one of those mighty shoals.
0:07:41 > 0:07:45It is quite common for prey animals to stick together in large numbers.
0:07:45 > 0:07:50This is perhaps where you see most definitively why they do it.
0:07:50 > 0:07:53First of all, in a shoal of fish this size, you have many,
0:07:53 > 0:07:56many eyes on the lookout for a threat.
0:07:56 > 0:07:59100,000 fish are much more likely to see
0:07:59 > 0:08:02an approaching predator than 100 fish are.
0:08:02 > 0:08:06Next, you are looking at what seems to be one huge, great
0:08:06 > 0:08:08single, shimmering organism.
0:08:08 > 0:08:10It is almost impossible for a predator
0:08:10 > 0:08:14to pick out any one individual that it might want to feed on.
0:08:14 > 0:08:17So it can easily swim into this shoal of fish
0:08:17 > 0:08:19and come up with nothing at all.
0:08:19 > 0:08:24The shoal looks incredibly enticing, but it is certainly not an easy meal.
0:08:27 > 0:08:29Right, back to the hunt.
0:08:29 > 0:08:31'The dolphins are just metres from the sardines,
0:08:31 > 0:08:34'and are poised and ready to strike.
0:08:34 > 0:08:37'This massive, churning mass of sardines is tricky to get close to.
0:08:37 > 0:08:41'This is where the dolphins' teamwork really comes into play.
0:08:41 > 0:08:45'Each dolphin dives underneath the sardines and drives them
0:08:45 > 0:08:48'upwards towards the surface, creating a smaller,
0:08:48 > 0:08:50'tighter shoal called a bait ball.
0:08:50 > 0:08:52'But the sardines don't panic.
0:08:52 > 0:08:54'They keep their shape and move in unison,
0:08:54 > 0:08:58'making it hard for the dolphins to pick out a single target,
0:08:58 > 0:09:00'so the dolphins pull out their secret weapon.'
0:09:00 > 0:09:03Just before the dolphins attack, they set their sonar to stun mode.
0:09:04 > 0:09:07They use it at a far higher intensity,
0:09:07 > 0:09:11and it completely scrambles the fish's hearing, making them panic.
0:09:13 > 0:09:16'With their plan in full effect, the lead dolphin dives in,
0:09:16 > 0:09:19'scattering and breaking up the fish.
0:09:19 > 0:09:22'The rest of the pod follows suit.
0:09:22 > 0:09:24'The sardines now search for safety in the crowd.
0:09:24 > 0:09:28'With so many fish in the shoal, their chances of survival are good.
0:09:28 > 0:09:33'All they can really do is twist and turn together and hope to stay alive.
0:09:33 > 0:09:35'It may look like a devastating attack,
0:09:35 > 0:09:39'but in the end, the pod will probably only eat around 1,000 fish.
0:09:39 > 0:09:44'In a shoal of maybe 100,000 sardines, that won't make a dent.'
0:09:47 > 0:09:51We think of dolphins as being friendly, smiley, brainy mammals.
0:09:51 > 0:09:53Certainly, they are very intelligent.
0:09:53 > 0:09:57But they are also completely ruthless when they are looking for a meal,
0:09:57 > 0:10:00as our sardines certainly found out.
0:10:00 > 0:10:04'Despite their sophisticated sonar, streamlined swimming and teamwork,
0:10:04 > 0:10:09'the dolphin pod attack wasn't enough to do much damage,
0:10:09 > 0:10:13'thanks to the sardines' nifty speed, acute hearing
0:10:13 > 0:10:17'and their force of numbers, ensuring the shoal survived to swim again.'
0:10:21 > 0:10:24Now, onto our next pair of hunters locked in a battle for survival.
0:10:25 > 0:10:28'This is the killer whale, or orca.
0:10:28 > 0:10:32'They are sophisticated, co-ordinated pack hunters.'
0:10:35 > 0:10:37Up against it is this -
0:10:37 > 0:10:42'the biggest and baddest of all the sea lions, the Steller sea lion.'
0:10:43 > 0:10:45But which has the edge in the race for life?
0:10:45 > 0:10:47It is time to go Deadly 360.
0:10:51 > 0:10:55'We join the hunt moments before the final strike.
0:10:55 > 0:10:57'A Steller sea lion is all alone in deep water
0:10:57 > 0:11:00'and is unaware of what lies beneath...
0:11:00 > 0:11:02'A killer whale.
0:11:02 > 0:11:07'It is speeding towards its target. The sea lion is in serious trouble.'
0:11:09 > 0:11:12If we freeze the action at this critical moment,
0:11:12 > 0:11:16who do the odds favour, the predator or the prey?
0:11:16 > 0:11:19As ever, we need to examine this hunt in forensic detail.
0:11:19 > 0:11:22To do that, we have to take it back to the start.
0:11:24 > 0:11:27'Well, let's find out where all this happened.
0:11:28 > 0:11:30'We are now travelling to the Pacific Ocean,
0:11:30 > 0:11:33'along the west coast of British Columbia in Canada.
0:11:35 > 0:11:39'It is here in these chilly waters that the killer whales are hunting.
0:11:41 > 0:11:44'Orca are the largest member of the dolphin family,
0:11:44 > 0:11:47'and like other dolphins, they live in pods, travelling,
0:11:47 > 0:11:49'socialising and hunting together.
0:11:49 > 0:11:53'On the menu today is one of their favourite meals,
0:11:53 > 0:11:55'the Steller sea lion.
0:11:55 > 0:11:58'These coasts are perfect for sea lion colonies.
0:11:58 > 0:12:01'There are rocky platforms, ideal for raising a family,
0:12:01 > 0:12:03'and with hungry pups to feed,
0:12:03 > 0:12:06'these waters offer a plentiful supply of fish.'
0:12:06 > 0:12:08So, that's our location.
0:12:08 > 0:12:11What sort of attributes do our predator and prey have
0:12:11 > 0:12:15that would give them an advantage in this kind of environment?
0:12:15 > 0:12:18'The killer whale has some pretty impressive stats.
0:12:18 > 0:12:21'First up, its size.
0:12:21 > 0:12:23'Weighing the equivalent of four hefty cars,
0:12:23 > 0:12:28'it is capable of moving at great speed in pursuit of its dinner.
0:12:28 > 0:12:30'Next, its three-metre tail,
0:12:30 > 0:12:33'powerful enough to deliver a fatal blow to its prey.
0:12:33 > 0:12:35'And lastly, hunting skills.
0:12:35 > 0:12:38'Their attacks are timed to perfection.
0:12:38 > 0:12:41'They are ruthless and focused.'
0:12:41 > 0:12:43An impressive line-up of hunting skills,
0:12:43 > 0:12:45but as ever on Deadly 360,
0:12:45 > 0:12:50our prey animal is armed with some pretty impressive means of defence.
0:12:50 > 0:12:53'The sea lions are equipped with both agility and speed.
0:12:53 > 0:12:54'Although cumbersome on dry land,
0:12:54 > 0:12:57'once in the water they are like graceful ballerinas,
0:12:57 > 0:13:00'with the ability to outmanoeuvre their attacker.
0:13:01 > 0:13:05'Add to that jaws that can deliver a bite equal to a grizzly bear
0:13:05 > 0:13:07'and you've got one tough cookie.'
0:13:09 > 0:13:11With two such talented animals,
0:13:11 > 0:13:13this hunt is going to be a close-run thing.
0:13:13 > 0:13:15Let's see what happens.
0:13:15 > 0:13:19'It's early morning and the sea lions are out hunting,
0:13:19 > 0:13:22'but it's the end of summer and a lack of fish makes it tough.
0:13:22 > 0:13:26'They now have to head out to deeper waters to find a meal.
0:13:26 > 0:13:28'And just a few miles down the coast,
0:13:28 > 0:13:30'a pod of killer whales are also on the move.
0:13:30 > 0:13:33'These orca have superlative stamina,
0:13:33 > 0:13:37'covering vast areas of ocean in search of their food.'
0:13:37 > 0:13:38But this is a six-tonne mammal
0:13:38 > 0:13:42and it is moving through the water absolutely effortlessly.
0:13:42 > 0:13:45How on earth do they manage that?
0:13:45 > 0:13:49The killer whale is the largest member of the dolphin family
0:13:49 > 0:13:52and a fully-grown male is absolutely enormous.
0:13:52 > 0:13:55In fact, I think we are going to need to see it larger than this.
0:13:55 > 0:13:57I can't show you a life-size model,
0:13:57 > 0:13:59because it would be way too big to fit into Deadly HQ.
0:13:59 > 0:14:01Here is one at about half life-size.
0:14:02 > 0:14:06Well, even at this size, it's still pretty impressive.
0:14:06 > 0:14:10This is only about the length of a fairly well-fed calf.
0:14:10 > 0:14:13This animal is really built for speed.
0:14:13 > 0:14:18The killer whale is capable of having burst of up to 30 mph,
0:14:18 > 0:14:22thanks to the muscles, which are here.
0:14:22 > 0:14:24Now, killer whales are mammals,
0:14:24 > 0:14:26so the way their spine articulates is very much the same
0:14:26 > 0:14:30as you will see in a horse or a cheetah - in an up and down motion.
0:14:30 > 0:14:34This means that it can't have its tail flukes orientated vertically,
0:14:34 > 0:14:37as you will see in a fish that swims from side to side.
0:14:37 > 0:14:42Instead, the flukes have to be horizontal, like this.
0:14:42 > 0:14:47This is actually a fully scaled-up male killer whale's tale.
0:14:47 > 0:14:51Look at the size of it! It's three metres across.
0:14:51 > 0:14:54It is not surprising that it can generate so much force.
0:14:55 > 0:14:57You have to say,
0:14:57 > 0:14:59the killer whale would vie for the title
0:14:59 > 0:15:01of the mightiest predator on Earth.
0:15:04 > 0:15:06'Right, back to the hunt.
0:15:06 > 0:15:10'The killer whales have arrived in the bay and spotted the sea lions,
0:15:10 > 0:15:13'but they're keeping their distance from the shore.
0:15:14 > 0:15:17'Sea lions have sensitive hearing, to alert them to predators,
0:15:17 > 0:15:20'but this is only one of a whole range of special adaptations
0:15:20 > 0:15:22'these animals have.'
0:15:22 > 0:15:25A fully-grown male Steller sea lion can be three metres in length
0:15:25 > 0:15:28and weigh as much as a tonne,
0:15:28 > 0:15:31but they're incredibly manoeuvrable underwater.
0:15:31 > 0:15:33They create their forward thrust
0:15:33 > 0:15:36using their four limbs, which are shaped into flippers.
0:15:36 > 0:15:39The rear flippers are pretty much used to give them direction.
0:15:39 > 0:15:41That sinuous, streamlined body
0:15:41 > 0:15:44means they can move in all kinds of different shapes
0:15:44 > 0:15:47and evade even the most tenacious of predators.
0:15:49 > 0:15:52'If any predator can get close enough to these guys,
0:15:52 > 0:15:55'they will find themselves face to face with this set of teeth.'
0:15:57 > 0:16:00I am hoping to prove to you now that they come plenty well-equipped
0:16:00 > 0:16:02to take care of themselves.
0:16:02 > 0:16:06I remember the first time that I saw a sea lion skull,
0:16:06 > 0:16:10I couldn't believe that this could belong to the same playful,
0:16:10 > 0:16:13intelligent animal that I had seen in the wild.
0:16:13 > 0:16:16After all, this is bigger than a lion's skull.
0:16:16 > 0:16:20Sea lions have 34-38 teeth. Look at the size of them!
0:16:20 > 0:16:24Their canines are up to seven centimetres in length and are sharp
0:16:24 > 0:16:26and slightly curved to grip onto their prey.
0:16:26 > 0:16:28Having a skull this large means they can deliver a bite
0:16:28 > 0:16:31that could even injure an orca.
0:16:31 > 0:16:34If you think I'm overstating how intimidating
0:16:34 > 0:16:37a big, male sea lion can be, I have been in the water with them
0:16:37 > 0:16:41and I can promise it is as scary as any shark encounter.
0:16:45 > 0:16:46Oh!
0:16:48 > 0:16:51He is gigantic!
0:16:51 > 0:16:53This is spectacular!
0:16:53 > 0:16:56Wow!
0:16:57 > 0:16:59That is a big male Steller sea lion.
0:16:59 > 0:17:03At the moment, the animals do seem kind of playful and inquisitive,
0:17:03 > 0:17:06but because they are so very, very big...
0:17:07 > 0:17:09..it's, erm, it's a bit unnerving, actually.
0:17:11 > 0:17:13Oh, crikey! There was close!
0:17:14 > 0:17:19It grabbed me. Ow! Ah, that hurt!
0:17:20 > 0:17:23So, I've seen first-hand that being in the water with
0:17:23 > 0:17:27a Steller sea lion can be just as frightening as any shark encounter.
0:17:27 > 0:17:30Let's see how the sea lion gets on against an orca.
0:17:31 > 0:17:33'We are into the final stages of the hunt.
0:17:33 > 0:17:37'The whales are waiting out of sight of the sea lions.
0:17:37 > 0:17:39'It's too risky to attack the group.
0:17:39 > 0:17:42'The orca's best bet is to wait for one to wander off.
0:17:43 > 0:17:45'It looks like it's been worth the wait.
0:17:45 > 0:17:49'One of the male sea lions is hunting alone
0:17:49 > 0:17:52'and that makes him the perfect target.
0:17:52 > 0:17:55'But any attacking whale will still need the element of surprise.
0:17:56 > 0:18:00'Hunting a one-ton, three-metre sea lion isn't easy.
0:18:00 > 0:18:03'OK, the lead killer whale is making a move.
0:18:03 > 0:18:07'It drives upwards, using the power from its three-metre tail
0:18:07 > 0:18:10'to rocket towards the surface at astonishing speed.
0:18:10 > 0:18:12'And...
0:18:12 > 0:18:14'Oh, wow!
0:18:14 > 0:18:17'It blows the sea lion clean out of the water.'
0:18:17 > 0:18:21Well, that was one of the most extraordinary kills
0:18:21 > 0:18:24you will ever see, and definitely worth another look.
0:18:24 > 0:18:28'You can see six tonnes of killer whale coming racing
0:18:28 > 0:18:31'towards the surface and hitting the sea lion
0:18:31 > 0:18:33'straight into its underbelly.'
0:18:33 > 0:18:37Really, it is going to be pretty much all over in that initial strike,
0:18:37 > 0:18:41but just to make sure, it hits it with a punishing tail slap.
0:18:41 > 0:18:44Now, there is no doubt that sea lion is dead.
0:18:48 > 0:18:52Orca have a vast array of different hunting strategies
0:18:52 > 0:18:55and also potential prey.
0:18:55 > 0:18:59These come with a varying degree of success rate and also of risk.
0:18:59 > 0:19:02You have to say that this is one of the most dangerous kind of hunt
0:19:02 > 0:19:04they could possibly take on.
0:19:04 > 0:19:07This time, the risk was worthwhile.
0:19:07 > 0:19:10'The sea lion's agility...
0:19:10 > 0:19:14'speed...and deadly jaws just weren't quite enough...
0:19:16 > 0:19:22'..against the whale's phenomenal power, flat-out pace and precision.'
0:19:26 > 0:19:30This is our last deadly duo, locked in a battle for life or death.
0:19:32 > 0:19:34'This is the mighty humpback whale.
0:19:34 > 0:19:38'At around 30 tonnes, it is one of the largest creatures on earth.'
0:19:38 > 0:19:42Up against it is this, the North Atlantic herring.
0:19:42 > 0:19:46'With reflective scales, they are the illusionists of the water world.'
0:19:46 > 0:19:50But which animal has the edge in the race for survival?
0:19:50 > 0:19:52It is time to go 360.
0:19:56 > 0:20:00'We witness the final stage of the hunt.
0:20:00 > 0:20:02'The herring have detected the humpback's approach
0:20:02 > 0:20:06'and dropped down into deeper water and the whales give chase.'
0:20:08 > 0:20:09Well, based on size alone,
0:20:09 > 0:20:12you would have to say it looks like the prey is done for.
0:20:12 > 0:20:16But don't give up hope yet. It's rarely as simple as that.
0:20:16 > 0:20:20Let's rewind to the start of the hunt and begin our investigation.
0:20:22 > 0:20:25'First off, let's find out where this hunt happened.
0:20:25 > 0:20:28'Well, we are staying in the Pacific Ocean, but heading
0:20:28 > 0:20:31'further north, into the waterways of Alaska.
0:20:32 > 0:20:36'It's summer and these waters have attracted a massive number
0:20:36 > 0:20:38'of herring, to feed on the rich plankton.
0:20:38 > 0:20:42'It is this event that triggers the humpback's annual migration
0:20:42 > 0:20:44'to these feeding grounds.
0:20:44 > 0:20:46'They've spent the winter in the warm waters
0:20:46 > 0:20:49'of the south and have travelled 3,000 miles to take advantage
0:20:49 > 0:20:51'of these huge shoals of fish.'
0:20:54 > 0:20:56So, that is where this drama's taking place,
0:20:56 > 0:20:58but how will the environmental factors
0:20:58 > 0:21:01affect our two animals' survival and hunting skills?
0:21:03 > 0:21:06'Well, the humpbacks have evolved a two-metre-wide mouth,
0:21:06 > 0:21:09'to help them hoover up thousands of fish.
0:21:09 > 0:21:11'They are the most vocal of whales,
0:21:11 > 0:21:15'and can produce screams of 180 decibels, to confuse their prey.
0:21:15 > 0:21:20'Plus, their fishing technique, which makes them a wonder whale.'
0:21:20 > 0:21:23So, I think it is clear we are dealing with another
0:21:23 > 0:21:25well-equipped predator,
0:21:25 > 0:21:28but how is our prey going to try and neutralise the threat?
0:21:30 > 0:21:32'The herring has numbers in its favour.
0:21:32 > 0:21:35'Up to two million can live in a shoal.
0:21:37 > 0:21:39'And, just like the sardines,
0:21:39 > 0:21:42'shoaling is also their strategy of choice.
0:21:42 > 0:21:44'It is teamwork on a massive scale.
0:21:44 > 0:21:47'They also have one other trick, their reflective scales.
0:21:47 > 0:21:50'In these numbers, it is a dazzling defence.'
0:21:52 > 0:21:55OK, now we have all the background, let's get the hunt underway.
0:21:57 > 0:21:59'We join the humpbacks as they reach the waters of Alaska.
0:21:59 > 0:22:03'After eating nothing for six months, they are starving,
0:22:03 > 0:22:06'but their journey isn't over.
0:22:06 > 0:22:08'The final leg takes them into the maze of waterways
0:22:08 > 0:22:09'to their feeding grounds.
0:22:09 > 0:22:13'When it comes to feeding, they rely on their massive mouths.'
0:22:18 > 0:22:21And the humpback certainly has that.
0:22:21 > 0:22:24The mouth is nearly four metres long and two metres wide,
0:22:24 > 0:22:27which is big enough to swallow a fridge freezer.
0:22:28 > 0:22:30'So with mouths like that,
0:22:30 > 0:22:33'how do the herring avoid getting munched?
0:22:33 > 0:22:36'They live together in large numbers, for protection.
0:22:36 > 0:22:38'And what a defence!
0:22:38 > 0:22:42'It's a beautiful display of choreography and agility.'
0:22:44 > 0:22:47Just like the sardines, the herring's scales are actually transparent.
0:22:47 > 0:22:50All of the colour of the fish comes from a layer
0:22:50 > 0:22:52of pigment cells underneath the scales.
0:22:52 > 0:22:57These give it a metallic sheen, which functions almost like a mirror.
0:22:57 > 0:23:00When light hits the fish, it scatters in all directions,
0:23:00 > 0:23:02making it difficult for a potential predator
0:23:02 > 0:23:05to select one individual fish.
0:23:05 > 0:23:08But how on earth do these fish manage to stay in formation?
0:23:08 > 0:23:09Let's find out.
0:23:10 > 0:23:13The many individual fish within a shoal
0:23:13 > 0:23:16keep themselves in formation with a couple of simple mechanisms.
0:23:16 > 0:23:19The first is eyesight -
0:23:19 > 0:23:20watching your neighbour
0:23:20 > 0:23:22and maintaining a constant distance from them.
0:23:22 > 0:23:25But the second is a more complex organ
0:23:25 > 0:23:28called the lateral line, which runs down the length of each fish.
0:23:28 > 0:23:31This can detect the changes in movement in the water,
0:23:31 > 0:23:33the wakes that are left behind
0:23:33 > 0:23:35as other fish are swimming around it.
0:23:35 > 0:23:38As a predator darts into the shoal, the rules change
0:23:38 > 0:23:41and all the fish scatter in completely different directions.
0:23:41 > 0:23:43They then have to get back into formation
0:23:43 > 0:23:45as quickly as they possibly can.
0:23:45 > 0:23:48Any fish that lingers too long on the outskirts
0:23:48 > 0:23:51is exactly the one that's likely to get targeted.
0:23:51 > 0:23:54Let's see how these herring fare
0:23:54 > 0:23:56against one of the largest mouths in the ocean.
0:23:58 > 0:24:02'Now an attacker's nearby, their defence strategy goes into action.
0:24:02 > 0:24:06'The shoal drops down in the water, to about 35 metres.
0:24:06 > 0:24:10'This gives them enough room to keep in formation.
0:24:10 > 0:24:12'Advantage to the herring.
0:24:12 > 0:24:14'But it may not be enough.
0:24:14 > 0:24:16'The humpbacks have arrived and make their move.
0:24:16 > 0:24:19'One whale gives chase and finds the shoal down in deep water.
0:24:19 > 0:24:24'With this many fish, it will need a team effort to catch them.
0:24:24 > 0:24:26'This is where the rest of the whales come in,
0:24:26 > 0:24:30'diving down to join the lead whale.
0:24:30 > 0:24:32'These humpbacks are hunting in a way only 100 whales
0:24:32 > 0:24:34'in the world have learned to do.
0:24:34 > 0:24:36'And this is just phase one.'
0:24:36 > 0:24:38So how does that work?
0:24:38 > 0:24:43A group of whales will actually swim around
0:24:43 > 0:24:45and underneath a shoal of fish.
0:24:45 > 0:24:48While they're doing that, one particular whale will call,
0:24:48 > 0:24:50to synchronise the group.
0:24:50 > 0:24:52That sound can be incredibly loud,
0:24:52 > 0:24:55as much as 180 decibels,
0:24:55 > 0:24:57the equivalent of a jet engine.
0:24:58 > 0:25:01Humpbacks are known for producing some of the most beautiful
0:25:01 > 0:25:03and haunting sounds of any animal.
0:25:03 > 0:25:07They can also use sound to deadly effect.
0:25:07 > 0:25:09This waveform here represents what's going on
0:25:09 > 0:25:12in my voice as the volume is changing.
0:25:12 > 0:25:15As whales come in ready for the kill, they can produce sounds
0:25:15 > 0:25:19of up to 180 decibels, which would be more like this.
0:25:19 > 0:25:21WHALE SONG
0:25:21 > 0:25:24A sound of that scale travels through the water
0:25:24 > 0:25:26four times faster than it travels through air.
0:25:26 > 0:25:30Fish have a remarkably sensitive sense of hearing
0:25:30 > 0:25:32so you can imagine a sound like this
0:25:32 > 0:25:36coming raging through a shoal must be absolutely deafening.
0:25:36 > 0:25:38This confuses the fish
0:25:38 > 0:25:42and makes it much more easy for the humpbacks to overpower them.
0:25:42 > 0:25:45Let's see this incredible animal at work.
0:25:48 > 0:25:51'Back down at 35 metres below the surface,
0:25:51 > 0:25:54'the humpback's screams are having the desired effect on the herring.
0:25:54 > 0:25:57'There's panic within the shoal.
0:25:57 > 0:26:01'With so many whales, the herring change tactics and try to escape.
0:26:01 > 0:26:03'The humpbacks have to act fast.
0:26:03 > 0:26:08'They bring out their final weapon and phase two goes into action.'
0:26:08 > 0:26:11They start blowing air out of their blowholes,
0:26:11 > 0:26:13creating a tangible curtain of shimmering bubbles,
0:26:13 > 0:26:16which the herring simply won't swim out of.
0:26:18 > 0:26:21'As the cage of bubbles rises from beneath,
0:26:21 > 0:26:25'the herring are funnelled upwards, with nowhere to go.
0:26:25 > 0:26:27'Now the humpbacks strike and just open wide.
0:26:35 > 0:26:37'Using this method, the whales will continue feeding
0:26:37 > 0:26:39'until all of the herring are gone.
0:26:39 > 0:26:42'That can be as much as two tonnes in a day.
0:26:44 > 0:26:48'That is like me eating 60,000 fish fingers.'
0:26:48 > 0:26:52Quite often on Deadly 360, when we have a really large animal
0:26:52 > 0:26:55going up against lots of very, very small animals,
0:26:55 > 0:26:58the smaller animals succeed by force of numbers.
0:26:58 > 0:27:00Not this time around.
0:27:00 > 0:27:03Humpbacks will quite often keep feeding on a shoal of herring
0:27:03 > 0:27:05until there is simply nothing left.
0:27:05 > 0:27:07That's what happened in this case.
0:27:07 > 0:27:10The herring's combination of synchronised swimming,
0:27:10 > 0:27:12stunning scales
0:27:12 > 0:27:14and huge numbers were impressive,
0:27:14 > 0:27:17but they just couldn't escape
0:27:17 > 0:27:18the humpbacks' massive mouths,
0:27:18 > 0:27:21stunning song
0:27:21 > 0:27:23and tactical teamwork.
0:27:29 > 0:27:32The whales and dolphins are endlessly fascinating.
0:27:32 > 0:27:33They have large brains,
0:27:33 > 0:27:36even when considered in proportion to their massive bodies.
0:27:36 > 0:27:39So they are intelligent, they can communicate,
0:27:39 > 0:27:42they can be social and they can use these cerebral skills
0:27:42 > 0:27:46to catch a dazzling variety of seafood.
0:27:46 > 0:27:48That's all we have time for.
0:27:48 > 0:27:52Join us next time as three more pairs of animals go head to head
0:27:52 > 0:27:55and we analyse the action, Deadly 360 style.
0:27:55 > 0:27:58Subtitles by Red Bee Media Ltd
0:27:58 > 0:28:01E-mail subtitling@bbc.co.uk