0:00:03 > 0:00:05My name's Steve Backshall! Whoo!
0:00:05 > 0:00:10And this my search for the Deadly 60.
0:00:10 > 0:00:12That's not just animals that are deadly to me,
0:00:12 > 0:00:15but animals that are deadly in their own world.
0:00:17 > 0:00:20My crew and I are travelling the planet
0:00:20 > 0:00:23and you're coming with me every step of the way.
0:00:29 > 0:00:34This time on Deadly 60, we're in New Zealand.
0:00:34 > 0:00:37The team and I will travel the length of the country
0:00:37 > 0:00:40'to the southern coastline in search of an ocean giant.'
0:00:40 > 0:00:42Wow!
0:00:42 > 0:00:47'And to the alpine mountains to find a parrot, yes, a parrot,'
0:00:47 > 0:00:49with incredible intelligence.
0:00:51 > 0:00:54But we begin on the North Island,
0:00:54 > 0:00:57'where an unusual, strangely beautiful hunter lurks.'
0:00:57 > 0:01:00So we're starting down in the darkness.
0:01:07 > 0:01:12We're in the Waitomo Caves, in the North Island of New Zealand.
0:01:12 > 0:01:14They're really stunning,
0:01:14 > 0:01:17raging rivers cutting through limestone caverns
0:01:17 > 0:01:20full of beautiful geological features.
0:01:20 > 0:01:22But we haven't come here to see that.
0:01:22 > 0:01:24We've come here to find a very peculiar animal,
0:01:24 > 0:01:27one which feasts on the tiny flying insects
0:01:27 > 0:01:30that move through these passageways.
0:01:36 > 0:01:39These are the larvae of the fungus gnat.
0:01:39 > 0:01:41More descriptively known as glow worms.
0:01:41 > 0:01:45They live in cave systems like Waitomo,
0:01:45 > 0:01:49preying on hatching mayflies, midges and mosquitoes.
0:01:49 > 0:01:52They lure these flying insects in with their glowing bottom
0:01:52 > 0:01:55and when the prey flies too close,
0:01:55 > 0:01:57they get trapped in the sticky, mucus-covered lures.
0:01:57 > 0:02:00Once ensnared, there's no escape.
0:02:00 > 0:02:03The glow worms sense the vibrations of the struggling creature below
0:02:03 > 0:02:06and reel them to their mouth, where they're devoured.
0:02:09 > 0:02:13Many of these glow-worm cities are found deep inside Waitomo,
0:02:13 > 0:02:15so we're journeying into the blackness.
0:02:19 > 0:02:22OK, you'll have to pass me the camera here, Graham.
0:02:25 > 0:02:26Slithering through the caves
0:02:26 > 0:02:30with a chilly stream rushing round our ankles is pretty tricky,
0:02:30 > 0:02:35especially as we need to stop the cameras taking a swim.
0:02:38 > 0:02:42But there are many creatures who love the security of the caverns,
0:02:42 > 0:02:44not just the Waitomo glow worms,
0:02:44 > 0:02:46like this water spider.
0:02:47 > 0:02:52It's a female. I know that for sure, because underneath her
0:02:52 > 0:02:56is what looks like a kind of slightly dark, shrunken ping-pong ball.
0:02:56 > 0:02:58That's her egg sac. It's made out of silk.
0:02:58 > 0:03:02Inside there, there's probably 60, maybe 80, tiny eggs
0:03:02 > 0:03:06that will eventually hatch out into tiny spiderlings,
0:03:06 > 0:03:08which will scurry off and disperse.
0:03:08 > 0:03:09She carries them around like this,
0:03:09 > 0:03:12clutched in her mouth parts, until they're ready to hatch.
0:03:14 > 0:03:17Many spiders have this same maternal instinct.
0:03:17 > 0:03:20Some will carry their babies round on their backs when they hatch out.
0:03:20 > 0:03:24Spiders really don't deserve their grisly reputation.
0:03:27 > 0:03:30The deeper we go, the tighter it gets.
0:03:30 > 0:03:34I'm kind of wishing I'd eaten a little less for dinner last night!
0:03:34 > 0:03:36'I don't want to get stuck.'
0:03:36 > 0:03:38OK, Gray.
0:03:47 > 0:03:49Oh, that is nasty!
0:03:49 > 0:03:50HE GROANS
0:03:57 > 0:04:00Caves and me just don't get on.
0:04:06 > 0:04:10You hang here for a sec, Gray. 'But it was all worth it'
0:04:10 > 0:04:15for the bizarre, dangling prize we find in the blackness.
0:04:18 > 0:04:24Isn't that spectacular? It's like some fabulous natural chandelier.
0:04:24 > 0:04:26All of these silken threads
0:04:26 > 0:04:31are the work of tiny little larvae from fungus gnats.
0:04:31 > 0:04:35If you look at them closely, along the length of them,
0:04:35 > 0:04:37you can make out tiny blobs of mucus.
0:04:37 > 0:04:39It's very sticky.
0:04:39 > 0:04:42They work like fishing lines, hanging out in the air,
0:04:42 > 0:04:45trying desperately to catch a hold of flying insects.
0:04:45 > 0:04:48You can see here where it's worked.
0:04:48 > 0:04:54Right there is an adult winged mayfly.
0:04:55 > 0:05:00And it's just hanging suspended, caught in that silk.
0:05:00 > 0:05:03The vibrations it set off will alert the fungus gnat larvae
0:05:03 > 0:05:07and it'll reel in that line and munch down the insect.
0:05:14 > 0:05:17And they really are remarkable little predators.
0:05:17 > 0:05:19They have created here
0:05:19 > 0:05:22one of the most beautiful spectacles, in miniature,
0:05:22 > 0:05:23you will ever see.
0:05:23 > 0:05:28They are just like living stalactites made of silk.
0:05:28 > 0:05:31This is a truly exquisite display.
0:05:31 > 0:05:33But there's one perhaps even more beautiful,
0:05:33 > 0:05:36certainly more bizarre thing
0:05:36 > 0:05:39that these fungus gnats can do to attract prey.
0:05:39 > 0:05:43But to see that, we need to go to a different part of the cave system.
0:05:51 > 0:05:55In this part of the cave, there are even larger aggregations
0:05:55 > 0:05:59of the fungus gnat larvae and their glorious silken threads.
0:05:59 > 0:06:03You can see them hanging underneath the roof in the cave.
0:06:03 > 0:06:07But this is a much better place to see the next incredible trick
0:06:07 > 0:06:11that this animal has for enticing insects into its trap.
0:06:11 > 0:06:14Unfortunately, we can only see that in total darkness
0:06:14 > 0:06:18and this camera is no good at all at seeing in the dark.
0:06:18 > 0:06:23So we're going to have to switch to infrared.
0:06:23 > 0:06:26OK, hopefully, now, under infrared light,
0:06:26 > 0:06:30you can see the true beauty of these creatures.
0:06:30 > 0:06:35It looks like the stars at night on a particularly clear evening.
0:06:35 > 0:06:38That's actually created by chemicals inside the body
0:06:38 > 0:06:41of the fungus gnat larvae.
0:06:41 > 0:06:44And those are mixed together with oxygen to create a light,
0:06:44 > 0:06:48which is almost without heat, but is incredible in its intensity.
0:06:48 > 0:06:51And looking up here at the underside of this rocky ceiling,
0:06:51 > 0:06:55you can just see those larvae are everywhere.
0:06:55 > 0:06:59They can use that light to entice flying prey to come in close.
0:06:59 > 0:07:02Then, obviously, it gets stuck in this sticky, silken trap.
0:07:02 > 0:07:06It's just an incredibly inventive way, I guess,
0:07:06 > 0:07:08of getting your food to come to you.
0:07:09 > 0:07:14This bright light is genuinely a sinister neon attractant,
0:07:14 > 0:07:16as no insect can resist it.
0:07:16 > 0:07:21There can be literally hundreds on one cave wall and, in fact,
0:07:21 > 0:07:24the hungrier they are, the brighter they glow.
0:07:24 > 0:07:28Luring insects to their death, they're a real deadly beauty.
0:07:30 > 0:07:32So the fungus gnat larvae.
0:07:32 > 0:07:36They may be incredibly beautiful, but at the same time,
0:07:36 > 0:07:39they're fabulous experts at catching flying insects on the wing
0:07:39 > 0:07:44and, for that reason, I reckon they've got to go on the Deadly 60.
0:07:46 > 0:07:49It's a cave-dwelling predator
0:07:49 > 0:07:51with mucus covered fishing line lures
0:07:51 > 0:07:55and a beautiful, but irresistible, glow.
0:07:55 > 0:07:59The fungus gnat larvae definitely deserves its place on the Deadly 60.
0:08:05 > 0:08:10'Next up, a true giant. We've got some travelling to do.'
0:08:10 > 0:08:14New Zealand is made up of two major islands.
0:08:14 > 0:08:18We've been on the North Island so far, but now we're heading south.
0:08:20 > 0:08:24The South Island's famous for its marine life -
0:08:24 > 0:08:28from sea lions to dolphins.
0:08:28 > 0:08:30But also an animal that does battle with sea monsters
0:08:30 > 0:08:32in the depths of the ocean.
0:08:32 > 0:08:35We're just pulling into the South Island
0:08:35 > 0:08:37and this is really very exciting.
0:08:37 > 0:08:40Because the destination we're heading to now
0:08:40 > 0:08:41is a place where we hope to find
0:08:41 > 0:08:44one of the largest predatory animals on Earth.
0:08:44 > 0:08:47An animal that has a larger brain than any other creature -
0:08:47 > 0:08:49the magnificent sperm whale.
0:08:53 > 0:08:57These mighty giants are multiple world-record holders.
0:08:57 > 0:09:01They're the largest toothed whale, weighing up to 50 tonnes.
0:09:01 > 0:09:05They have the biggest brain and they're a champion free driver,
0:09:05 > 0:09:09regularly diving to over 1,000 metres to hunt giant squid.
0:09:09 > 0:09:10Forget T-Rex,
0:09:10 > 0:09:14this is one of the biggest predators that has ever lived.
0:09:15 > 0:09:21Kaikoura, here on South Island, is one of the best places in the world
0:09:21 > 0:09:23to see these predatory giants.
0:09:23 > 0:09:26And, as a tantalising tease, the local museum has artefacts
0:09:26 > 0:09:29that hint at the true scale of the sperm whale.
0:09:29 > 0:09:33This is half of the jawbone of a sperm whale.
0:09:33 > 0:09:36I guess the first and most impressive thing about it
0:09:36 > 0:09:38is just the size of it.
0:09:38 > 0:09:40It's absolutely vast.
0:09:40 > 0:09:44This half of the jawbone weighs as much as I do
0:09:44 > 0:09:48and it's filled with teeth like that.
0:09:48 > 0:09:50Unbelievably impressive.
0:09:50 > 0:09:54These are used primarily for scoffing down its prey, which are
0:09:54 > 0:09:58things like giant squid, down in the darkest parts of the ocean.
0:09:58 > 0:10:01But they're also used amongst males for battles
0:10:01 > 0:10:03and you'll often see on mature males
0:10:03 > 0:10:06they'll have scarring where teeth have been raked down
0:10:06 > 0:10:08the side of their body.
0:10:08 > 0:10:09This here?
0:10:09 > 0:10:11That is one of its main weapons.
0:10:13 > 0:10:17Sperm whales come unusually close to shore by Kaikoura,
0:10:17 > 0:10:19'but they could be hundreds of miles away.'
0:10:19 > 0:10:22So we have an awful lot of deep blue sea to search
0:10:22 > 0:10:24in order to find our target.
0:10:24 > 0:10:29If only we had some eyes in the sky. Luckily, we've got just that.
0:10:37 > 0:10:40Woo-hoo!
0:10:43 > 0:10:47A perfect way to go looking for a whale.
0:10:47 > 0:10:51It gives you so much better perspective from up high.
0:10:51 > 0:10:54We can see for miles and they are such large animals,
0:10:54 > 0:10:58that when they come to the surface, they should become obvious,
0:10:58 > 0:11:00particularly when the sea is as flat as it is now.
0:11:04 > 0:11:08We're scanning the sea, looking for a tiny tell-tale puff
0:11:08 > 0:11:11of what looks like smoke.
0:11:11 > 0:11:15It's the spray that's exhaled from the whale's blowhole.
0:11:17 > 0:11:21'Then suddenly, I spot something in the distance.'
0:11:21 > 0:11:23OK. We've got one!
0:11:23 > 0:11:28There's a whale-watching boat we can see about a mile in front of us.
0:11:28 > 0:11:30And just a tiny puff of spray in front of it,
0:11:30 > 0:11:34so there's a whale at the surface there.
0:11:34 > 0:11:37All we've got to rely on now is it stays there long enough
0:11:37 > 0:11:39for us to get a good look at it.
0:11:43 > 0:11:45Yes, I see it!
0:11:47 > 0:11:48Wow!
0:11:51 > 0:11:54That is magnificent.
0:11:55 > 0:11:57I mean, really, it's only from up here
0:11:57 > 0:12:00that you get any sense of the scale of the animal.
0:12:00 > 0:12:05I can actually see this alongside a whale-watching boat
0:12:05 > 0:12:08and it's longer than the boat. It's enormous!
0:12:11 > 0:12:15I reckon it's got to be 16 or 17 metres long.
0:12:15 > 0:12:18At the moment, it's just resting at the surface.
0:12:18 > 0:12:23Any second now, it will give a big kick of those mighty tail flukes,
0:12:23 > 0:12:25move forward and dive down.
0:12:25 > 0:12:28Once it's gone, it's going to be underwater for a very long time.
0:12:28 > 0:12:32This is one of mother nature's greatest free divers.
0:12:32 > 0:12:34They can dive to several thousand metres,
0:12:34 > 0:12:37diving for well over an hour on one breath of air.
0:12:39 > 0:12:41And the reason for these long dives
0:12:41 > 0:12:44is they have to eat more than a cow's weight of fish
0:12:44 > 0:12:45and squid every day.
0:12:48 > 0:12:50OK, Gray, stay on him.
0:12:50 > 0:12:53Here comes the dive. Get ready for it.
0:13:08 > 0:13:10How's about that?
0:13:10 > 0:13:14One big dive and he's down into the depths of the ocean.
0:13:14 > 0:13:16But that was out of this world!
0:13:16 > 0:13:21'Later on, we'll aim to put ourselves into the sperm whale's world'
0:13:21 > 0:13:25for an intimate encounter with this vast, regal beast.
0:13:28 > 0:13:31But, first, inland to the mountains
0:13:31 > 0:13:34'for a truly curious contender for my list.'
0:13:34 > 0:13:38Usually on Deadly 60, we feature animals that I guess are obvious.
0:13:38 > 0:13:41No-one's going to complain if I put a great white shark,
0:13:41 > 0:13:44a Bengal tiger or a Nile crocodile on my list.
0:13:44 > 0:13:45But, every once in a while,
0:13:45 > 0:13:48we feature an animal that is more off the wall,
0:13:48 > 0:13:50perhaps a little unusual.
0:13:50 > 0:13:51That's exactly the reason
0:13:51 > 0:13:54that we're heading into the mountains of New Zealand.
0:13:58 > 0:14:02The animal in question is called the kea.
0:14:02 > 0:14:04It's a montane parrot,
0:14:04 > 0:14:07capable of surviving the most extreme alpine conditions.
0:14:07 > 0:14:10It has a reputation as a highly intelligent bird
0:14:10 > 0:14:12that works cooperatively with its mates
0:14:12 > 0:14:14and is naturally inquisitive.
0:14:14 > 0:14:17They do a lot of scavenging, going through our rubbish
0:14:17 > 0:14:20and tearing the rubber out of tourists' windscreens.
0:14:20 > 0:14:24So far, so...well, charming.
0:14:24 > 0:14:28But, their can opener of a beak serves many purposes
0:14:28 > 0:14:33and it's a major part of what makes them deadly.
0:14:33 > 0:14:38'More of that later. First, let's meet this mischievous bird.'
0:14:38 > 0:14:40Because they're such brainy birds,
0:14:40 > 0:14:46they always take an interest at anything new in their environment.
0:14:46 > 0:14:47And, um, our tripod
0:14:47 > 0:14:52is obviously something that needs to little bit of investigation.
0:14:59 > 0:15:01HE LAUGHS
0:15:03 > 0:15:06You can see him just looking at me and thinking,
0:15:06 > 0:15:10"Can I get away with it?" No! Not a chance!
0:15:12 > 0:15:16Oh. Now he's going for the other camera!
0:15:18 > 0:15:21I love the way they just cock their heads to one side,
0:15:21 > 0:15:24it really speaks of intelligence.
0:15:31 > 0:15:34Further up the road is a mountain pass
0:15:34 > 0:15:37'where the kea gather in large numbers.'
0:15:37 > 0:15:41Keas, lots of them. It's a good sight.
0:15:41 > 0:15:44Here we go, this is more like it.
0:15:49 > 0:15:52So this is a slightly wilder location
0:15:52 > 0:15:55and there are keas just about everywhere.
0:15:57 > 0:15:58KEA SCREECHES
0:15:58 > 0:16:04I guess this really shows what makes the kea such a tough bird.
0:16:04 > 0:16:07We're in a high alpine pass.
0:16:07 > 0:16:10At night time here, it would be down to almost freezing
0:16:10 > 0:16:12and, in the winter, well below freezing.
0:16:12 > 0:16:15But this animal is certainly tough enough
0:16:15 > 0:16:17to endure even the coldest temperatures
0:16:17 > 0:16:20with that thick, feathery plumage.
0:16:20 > 0:16:24But that's not why I'm thinking of putting them on the Deadly 60.
0:16:24 > 0:16:25'This is why.'
0:16:25 > 0:16:30They're a mastermind hunter, using team work and intelligence
0:16:30 > 0:16:32to track down and kill shearwater chicks
0:16:32 > 0:16:35before they have a chance to escape.
0:16:35 > 0:16:38The kea will stalk through the warren of shearwater nest holes,
0:16:38 > 0:16:42bending down, listening for any tell-tale sounds.
0:16:42 > 0:16:45When the chicks make the slightest movement or call,
0:16:45 > 0:16:49the kea swiftly digs down, using its beak like a pickaxe,
0:16:49 > 0:16:52tearing away the earth around the entrance.
0:16:53 > 0:16:58The chick is pulled from the nest to become kea food.
0:17:05 > 0:17:09So you can see how that sharply curved beak
0:17:09 > 0:17:13is not just at all for ripping apart windscreens.
0:17:13 > 0:17:17It can also be used to lethal effect.
0:17:17 > 0:17:20However, I really think it's this bird's intelligence
0:17:20 > 0:17:22that is the most interesting thing about them.
0:17:22 > 0:17:28Keas have actually learned to solve quite complex puzzles and tasks.
0:17:28 > 0:17:31But here in the wild, they're completely protected,
0:17:31 > 0:17:32so we're not allowed
0:17:32 > 0:17:34to intentionally interact with them.
0:17:34 > 0:17:35I do, however, know a place
0:17:35 > 0:17:37where I can show you for sure
0:17:37 > 0:17:40that keas are anything but bird-brained.
0:17:58 > 0:18:00So we are in Willowbank Wildlife Reserve in Christchurch
0:18:00 > 0:18:03and this is the perfect opportunity
0:18:03 > 0:18:06to show you the problem-solving skills of the kea.
0:18:06 > 0:18:11This rather impressive puzzle has a whole bunch of notches
0:18:11 > 0:18:14and tricks that the kea is going to have to solve to get its food reward.
0:18:14 > 0:18:18The food reward is a big lump of tasty cheese.
0:18:18 > 0:18:20Before we've even started,
0:18:20 > 0:18:22we've got our first intrigued customer.
0:18:24 > 0:18:27So it goes in the top.
0:18:27 > 0:18:29And we sit back and watch.
0:18:29 > 0:18:33'The kea here have never seen this puzzle before,'
0:18:33 > 0:18:34but they're instantly interested.
0:18:34 > 0:18:37They have this unusual ability to learn
0:18:37 > 0:18:41and to create new solutions to whatever problems they encounter -
0:18:41 > 0:18:44very much like human beings.
0:18:44 > 0:18:46It's this intelligence that helps them find prey
0:18:46 > 0:18:50and track down carcasses in the wild.
0:18:50 > 0:18:53That was absolutely brilliant.
0:18:53 > 0:18:54It's putting its eye down
0:18:54 > 0:18:57so it can look down into the tube at the cheese.
0:18:57 > 0:19:00The fact that it spotted it is a really good start.
0:19:00 > 0:19:03Now it has to figure out how to get at it.
0:19:04 > 0:19:09This kea seems to have decided to start the puzzle halfway down.
0:19:09 > 0:19:14Who knows if it's working out a solution or just destroying stuff?
0:19:14 > 0:19:16Whatever, it's created a shortcut in the puzzle,
0:19:16 > 0:19:20speeding the reward down the tunnel towards their waiting beaks.
0:19:22 > 0:19:24Yes! Fantastic.
0:19:24 > 0:19:27Stage one of the problem solved.
0:19:27 > 0:19:31Now it's got to figure out where that cheese is.
0:19:33 > 0:19:36And it doesn't take them long.
0:19:40 > 0:19:42This is good. Yes.
0:19:42 > 0:19:46The next stage of the puzzle solved.
0:19:50 > 0:19:51Just turn the wheel.
0:19:51 > 0:19:53They've done it again. Fantastic.
0:19:57 > 0:19:59Yes. Go on.
0:19:59 > 0:20:00'The food rewards
0:20:00 > 0:20:02'are almost at the bottom.'
0:20:02 > 0:20:04We're all secretly willing the kea on.
0:20:04 > 0:20:06Go on!
0:20:06 > 0:20:08One last stage to go.
0:20:28 > 0:20:31And success.
0:20:31 > 0:20:35The bold, beautiful, big-brained kea.
0:20:35 > 0:20:37They're kind of destructive,
0:20:37 > 0:20:40but they've got bags of personality and they're on my list.
0:20:40 > 0:20:42How about that?
0:20:48 > 0:20:51One of the most intelligent birds on Earth.
0:20:51 > 0:20:56Stealth hunters who can creep up on their prey unnoticed.
0:20:56 > 0:21:00A razor sharp beak that can be used for all kinds of deadly deeds.
0:21:00 > 0:21:05They aren't bird-brained, they're on the Deadly 60.
0:21:06 > 0:21:09Right, so back on the whale hunt. We're heading out at sea level
0:21:09 > 0:21:13to try and catch up with a whale as it surfaces to breathe.
0:21:15 > 0:21:20It's really important not to disturb the whale while it's resting,
0:21:20 > 0:21:24so the main boat is not allowed closer than 50 metres from the whale.
0:21:24 > 0:21:26But I have permission to approach in this kayak,
0:21:26 > 0:21:31much too small to bother a 50-tonne mega-beast.
0:21:32 > 0:21:35The seas off Kaikoura are incredibly rich,
0:21:35 > 0:21:38which explains why there's so much life around.
0:21:38 > 0:21:42But sperm whales tend to be associated with the deep sea.
0:21:42 > 0:21:45Normally, you would never find them coming in close to the coast.
0:21:45 > 0:21:49The reason they do here is because Kaikoura has
0:21:49 > 0:21:51a very unique profile to its seabed.
0:21:51 > 0:21:54So just a couple of miles out from the coast,
0:21:54 > 0:21:56it's over 1,000 metres deep.
0:21:56 > 0:21:59Go a little bit further, it's 2,000 metres deep.
0:21:59 > 0:22:01This is one of the few places on Earth
0:22:01 > 0:22:04where sperm whales will get very close to the land,
0:22:04 > 0:22:08which makes it just about the best place ever for wildlife.
0:22:08 > 0:22:12Although the seas can be a little bit rough.
0:22:12 > 0:22:13HE LAUGHS
0:22:16 > 0:22:18New Zealand's weather is famously changeable
0:22:18 > 0:22:21and, right now, it's changed to rubbish.
0:22:21 > 0:22:25With the swell, we could be metres from a whale and wouldn't see it.
0:22:25 > 0:22:28There is, though, another key to tracking sperm whales.
0:22:28 > 0:22:32And that's down to their being one of the loudest animals on Earth.
0:22:32 > 0:22:35CLICKING
0:22:35 > 0:22:39Sperm whales are really very noisy animals.
0:22:39 > 0:22:45They create clicks using an organ called the monkey lips in their head
0:22:45 > 0:22:49and send those sonic sound waves out into the water.
0:22:49 > 0:22:52When those hit something solid - that could be the land itself,
0:22:52 > 0:22:56it could be prey - the sound waves will bounce back to the sperm whale
0:22:56 > 0:22:58and it picks them up in its lower jaw
0:22:58 > 0:23:01and works out exactly what's in front of it
0:23:01 > 0:23:04and decides where it's going to move and what it's going to try and hunt.
0:23:04 > 0:23:08We've got here a hydrophone,
0:23:08 > 0:23:11which can pick up those clicking sounds underwater.
0:23:11 > 0:23:16So we're listening in now to try and hear where our sperm whale is.
0:23:16 > 0:23:18When we work out what direction it's in,
0:23:18 > 0:23:20we can just move towards it
0:23:20 > 0:23:22and quickly be there when it comes to the surface.
0:23:22 > 0:23:24CLICKING
0:23:28 > 0:23:31But it could be a bit of a wait.
0:23:31 > 0:23:34Sperm whales generally spend about an hour hunting in the depths.
0:23:34 > 0:23:37The underwater battle between the sperm whale
0:23:37 > 0:23:39and its prey the giant squid
0:23:39 > 0:23:42happens so deep in the ocean, it's never been filmed.
0:23:42 > 0:23:46But knowing it could be happening beneath me right now is pretty eerie.
0:23:51 > 0:23:53- That way.- That way.
0:23:53 > 0:23:56'And our whale is on the move.'
0:23:56 > 0:23:58So we need to keep tracking him.
0:23:58 > 0:24:03They can travel a kilometre between dives, so we don't want to lose him.
0:24:08 > 0:24:11When we check again, something's changed.
0:24:14 > 0:24:17OK, we've been tracking our whale using the hydrophone and getting some
0:24:17 > 0:24:21really loud clicks coming from this area we're over right now.
0:24:21 > 0:24:23But it's gone silent.
0:24:23 > 0:24:26Usually, a few minutes before they surface, that's what happens.
0:24:26 > 0:24:29They stop clicking because they're not hunting any more.
0:24:29 > 0:24:34So we're just waiting. Any second now it could break the surface.
0:24:34 > 0:24:37Very, very exciting.
0:24:43 > 0:24:44Come on, big fellow.
0:24:50 > 0:24:53There he is! Over there! Just over there, do you see him?
0:24:53 > 0:24:55Have you got him?
0:24:56 > 0:25:00He's about this 200 metres in front of us.
0:25:00 > 0:25:03OK.
0:25:03 > 0:25:05This is as close as we can come in the main boat.
0:25:05 > 0:25:08We have to keep our distance, but I can get closer in the kayak.
0:25:19 > 0:25:21I'm going to approach cautiously.
0:25:21 > 0:25:23The last thing I want to do is spook him.
0:25:23 > 0:25:26After all, he's at the surface to recuperate.
0:25:26 > 0:25:29This is his rest time in between hunts.
0:25:31 > 0:25:34He'll spend eight to ten minutes at the surface after a dive,
0:25:34 > 0:25:37taking in as much air as he can, oxygenating his blood,
0:25:37 > 0:25:40then storing the oxygen in his muscles
0:25:40 > 0:25:42before he heads back to the deep.
0:25:43 > 0:25:46I need to keep clear of those mighty tail flukes.
0:25:46 > 0:25:49One swipe could swat me and my kayak like a mosquito.
0:25:49 > 0:25:53But up close, able to smell his breath and see the sheen on his skin,
0:25:53 > 0:25:56it's one of most humbling moments imaginable.
0:25:57 > 0:26:01This is one of nature's giants.
0:26:03 > 0:26:06See, when you're up close,
0:26:06 > 0:26:11the massive "S" shaped blowhole on the head,
0:26:11 > 0:26:16which it's using to drive out all of the spent air from its lungs.
0:26:22 > 0:26:25Wow!
0:26:25 > 0:26:28The tail flukes are absolutely gigantic.
0:26:30 > 0:26:33They're almost as broad across as my kayak.
0:26:33 > 0:26:36And up they go!
0:26:36 > 0:26:39Totally dwarfing me.
0:26:39 > 0:26:42That was magnificent.
0:26:43 > 0:26:46Today has been a day of giants.
0:26:46 > 0:26:50And it's been one of the most special I have spent out on the seas,
0:26:50 > 0:26:54but sperm whales, that massive animal that's hunting in the dark
0:26:54 > 0:26:57beneath me now, just had to go on the Deadly 60.
0:26:57 > 0:27:02Look at that glassy patch of water where he was.
0:27:02 > 0:27:05That's all that remains of that mighty animal. Ha!
0:27:05 > 0:27:07And a little fur seal in the middle of it!
0:27:12 > 0:27:15It has the biggest brain on Earth,
0:27:15 > 0:27:18is the world's greatest free diver
0:27:18 > 0:27:22and they are the largest toothed carnivore ever known to have lived.
0:27:22 > 0:27:23The sperm whale is a
0:27:23 > 0:27:25world record breaking giant
0:27:25 > 0:27:27and an animal we should all
0:27:27 > 0:27:29be truly proud to have in our oceans.
0:27:31 > 0:27:35Snake! Gray, don't move because you are right on it.
0:27:35 > 0:27:36Ooh, hello.
0:27:36 > 0:27:39'Join me next time as I continue my search for the Deadly 60.'
0:27:39 > 0:27:41The devil carried away the camera.
0:27:53 > 0:27:56Subtitles by Red Bee Media Ltd