0:00:44 > 0:00:47The duels between hunters and hunted
0:00:47 > 0:00:50are as dramatic as any event in the natural world.
0:00:53 > 0:00:56The stakes could not be higher.
0:01:01 > 0:01:05For both, it's a matter of life and death.
0:01:09 > 0:01:13Yet, surprisingly, it's the hunters that usually fail.
0:01:17 > 0:01:20To have any chance of survival,
0:01:20 > 0:01:25predators must be perfectly tuned to their own hunting arenas.
0:01:33 > 0:01:36Every habitat brings a different challenge.
0:01:56 > 0:01:59This series will reveal, as never before,
0:01:59 > 0:02:05the extraordinary range of strategies predators use to catch their prey.
0:02:13 > 0:02:15But even for the most skilful...
0:02:17 > 0:02:20..success is never guaranteed.
0:03:05 > 0:03:08SCREECHING
0:03:08 > 0:03:09SNIFFS
0:03:09 > 0:03:11BARKS
0:03:13 > 0:03:15BARKS
0:03:16 > 0:03:17BARKS
0:03:24 > 0:03:25BARKS
0:03:25 > 0:03:28A female leopard on the prowl.
0:03:32 > 0:03:35Few predators instil more fear.
0:03:44 > 0:03:45SNIFFS
0:03:48 > 0:03:51Yet, out in the open,
0:03:51 > 0:03:53she has little chance of catching anything.
0:03:55 > 0:03:59To succeed, she must get within a few metres of her prey...
0:03:59 > 0:04:01undetected.
0:04:05 > 0:04:08Her strategy is to use cover,
0:04:08 > 0:04:11wearing it like a cloak of invisibility.
0:04:23 > 0:04:26She's an expert in stealth.
0:04:34 > 0:04:38Impala are her favourite prey.
0:04:43 > 0:04:46This one is just out of her range.
0:04:46 > 0:04:47SNIFFS
0:04:48 > 0:04:52She needs to get closer, within four metres.
0:04:53 > 0:04:56She only has a short burst of speed.
0:05:06 > 0:05:11She must stay hidden until she's in the strike zone.
0:05:20 > 0:05:21TWIG SNAPS
0:05:25 > 0:05:29But out of sight doesn't mean out of mind.
0:05:30 > 0:05:35Impala have acute hearing and a superb sense of smell.
0:05:35 > 0:05:36SNIFFS
0:05:47 > 0:05:52Now the only prey she can see is right out in the open.
0:05:58 > 0:06:02But leopards are the most versatile of all the big cats,
0:06:02 > 0:06:07adept at finding cover in the most unpromising places.
0:06:24 > 0:06:29The steep walls of the gully are now her cover for an ambush.
0:06:34 > 0:06:38The male puku is close enough, but he's too big to tackle.
0:06:40 > 0:06:44She needs to slip past him without being seen.
0:06:54 > 0:06:57If he spots her, he'll blow her cover.
0:06:59 > 0:07:00SNIFFS
0:07:16 > 0:07:18Slowly does it...
0:07:27 > 0:07:29To succeed here,
0:07:29 > 0:07:32she needs to find prey grazing close to the edge.
0:07:33 > 0:07:34Or better still,
0:07:34 > 0:07:36in the gully itself.
0:08:23 > 0:08:24Frustration.
0:08:27 > 0:08:30Success would have staved off hunger for a week.
0:08:34 > 0:08:37But while there's prey around, there's hope.
0:08:40 > 0:08:43Peeking over the top is a risk,
0:08:43 > 0:08:46but it's the quickest way to find a new target.
0:09:08 > 0:09:09SNIFFS
0:09:22 > 0:09:25A burst of speed of 40mph
0:09:25 > 0:09:27and it's all over in less than six seconds.
0:09:38 > 0:09:40Except...it isn't.
0:09:49 > 0:09:51Dazed and disorientated,
0:09:51 > 0:09:53the impala makes a miraculous escape.
0:09:59 > 0:10:02It's been the perfect stealth hunt
0:10:02 > 0:10:04and she's nothing to show for it.
0:10:07 > 0:10:12But then, six out of seven leopard hunts end in failure.
0:10:16 > 0:10:19A leopard's hunting strategy depends on finding cover.
0:10:21 > 0:10:23But how do you catch your prey
0:10:23 > 0:10:26in a place where there's literally nowhere to hide?
0:10:28 > 0:10:33That's the challenge facing Zambia's wild dogs.
0:10:39 > 0:10:43This close-knit pack is made up of one adult female
0:10:43 > 0:10:45and her 12 offspring from last year.
0:10:56 > 0:10:58Unlike the solitary leopard,
0:10:58 > 0:11:01wild dogs depend for their survival on teamwork.
0:11:11 > 0:11:13Dogs that play together...
0:11:13 > 0:11:15work together.
0:11:22 > 0:11:27Each morning, the pack heads out across the open plain,
0:11:27 > 0:11:28prospecting for prey.
0:11:32 > 0:11:35Mother decides which direction they go.
0:11:38 > 0:11:40The rest stay close.
0:11:47 > 0:11:52They'll keep going for miles until they find the right kind of prey.
0:11:59 > 0:12:02Adult zebra are too big a challenge.
0:12:04 > 0:12:07And the same goes for tsessebe.
0:12:14 > 0:12:17An oribi is an easier target.
0:12:19 > 0:12:21But is it worth the effort,
0:12:21 > 0:12:25especially on an oribi that's as fit and bouncy as this one?
0:12:28 > 0:12:31Better to save their energy for something bigger.
0:12:36 > 0:12:38A wildebeest.
0:12:40 > 0:12:42It's what they've been looking for.
0:12:50 > 0:12:53The dogs need to make the wildebeest run.
0:12:55 > 0:13:00Their success will depend on wearing him down in a long chase.
0:13:21 > 0:13:25While the prey's running, the dogs have the advantage.
0:13:40 > 0:13:43But when the wildebeest stand their ground, the tables are turned.
0:13:46 > 0:13:48Faced with a wall of horns,
0:13:48 > 0:13:51the pack is powerless.
0:13:51 > 0:13:56But not all the wildebeest have had the courage to stop.
0:14:03 > 0:14:05Now the real contest begins.
0:14:10 > 0:14:13The wildebeest are big and strong.
0:14:16 > 0:14:19But the dogs have stamina.
0:14:29 > 0:14:33Right now, hunters and hunted are clocking 40mph.
0:14:34 > 0:14:37The pack can keep this pace up for miles.
0:14:42 > 0:14:44The wildebeest can't.
0:14:57 > 0:14:59One wildebeest peels off.
0:14:59 > 0:15:01Then another two.
0:15:01 > 0:15:04The split confuses the inexperienced pack,
0:15:04 > 0:15:07sending them in different directions.
0:15:10 > 0:15:12The mother and one youngster continue on.
0:15:21 > 0:15:25The rest of the pack stop, believing they have an easier target.
0:15:36 > 0:15:37It's a mistake.
0:15:39 > 0:15:43Like a beast with two heads, each bull protects the other's rear.
0:15:45 > 0:15:46And the dogs can do nothing.
0:15:53 > 0:15:55Ahead, the chase continues.
0:15:56 > 0:15:59Another wildebeest peels off.
0:15:59 > 0:16:01Now the mother has just one in her sights.
0:16:03 > 0:16:06But it will mean nothing without the help of the rest of the pack.
0:16:08 > 0:16:11The situation here has reached stalemate.
0:16:15 > 0:16:18The young dogs have lost valuable time.
0:16:18 > 0:16:22They must try and catch up with their mother.
0:16:31 > 0:16:35Back at the front, the mother is beginning to tire.
0:16:38 > 0:16:39And the wildebeest knows it,
0:16:39 > 0:16:43bouncing to show he's still strong and not worth chasing.
0:16:46 > 0:16:50But fresh, young legs are catching up fast.
0:17:02 > 0:17:04When one dog tires,
0:17:04 > 0:17:08there's always another member of the team to take up the lead.
0:17:12 > 0:17:16The dogs now have the numbers to bring the wildebeest down.
0:17:27 > 0:17:30Each bite risks a broken jaw,
0:17:30 > 0:17:33but going for the legs is the only way to stop it.
0:17:36 > 0:17:39And they must do so before it reaches the safety of the herd,
0:17:39 > 0:17:42a few hundred metres ahead.
0:18:06 > 0:18:10After a 20-minute chase, the bull's energy is near spent.
0:18:14 > 0:18:19This time there will be no sanctuary within the herd.
0:18:21 > 0:18:24The dogs' stamina has been rewarded.
0:18:24 > 0:18:28All they must do now is to bring their quarry to the ground.
0:18:34 > 0:18:36Working as a pack
0:18:36 > 0:18:39allows wild dogs to take on prey ten times heavier
0:18:39 > 0:18:41than any one of them.
0:18:48 > 0:18:52But many mouths need a lot of food.
0:18:55 > 0:18:57The price they pay for these numbers
0:18:57 > 0:19:01is knowing they'll have to attempt the same thing again tomorrow...
0:19:01 > 0:19:03and every day.
0:19:09 > 0:19:13Teamwork and stamina on Africa's open plains
0:19:13 > 0:19:15have proved to be a winning combination.
0:19:22 > 0:19:26But in the dense and complex world of the jungle,
0:19:26 > 0:19:31hunting is a never-ending game of hide and seek.
0:19:36 > 0:19:39Here, it pays to sit still...
0:19:41 > 0:19:42..and blend in...
0:19:46 > 0:19:49..because you just never know who's watching.
0:20:02 > 0:20:06The Parson's chameleon is an expert
0:20:06 > 0:20:08in the see-and-not-be-seen game.
0:20:13 > 0:20:15It lets its eyes do all the work...
0:20:17 > 0:20:21..while the rest of its body moves in slow motion,
0:20:21 > 0:20:23so as not to scare possible targets.
0:20:25 > 0:20:29The problem is that it can only see prey if it moves.
0:20:31 > 0:20:33So is this a stick insect...
0:20:34 > 0:20:36..or a stick?
0:20:38 > 0:20:39Ah-hah...
0:20:41 > 0:20:44Time to unleash its secret weapon...
0:20:50 > 0:20:54..a tongue longer than its body.
0:20:59 > 0:21:03The Parson's close cousin, the nasutum chameleon,
0:21:03 > 0:21:06has the same weapon, but in miniature.
0:21:12 > 0:21:16As small as a matchstick, he needs to get much closer to its prey.
0:21:20 > 0:21:24But even with eyes as big as its stomach,
0:21:24 > 0:21:27this isn't the meal deal he was hoping for.
0:21:37 > 0:21:41In the jungle, it's hard finding the right-sized prey
0:21:41 > 0:21:43when you're a tiny predator.
0:21:49 > 0:21:52Promising opportunities
0:21:52 > 0:21:54can quickly turn to disappointment.
0:21:59 > 0:22:03Spotting any kind of prey in this dense, green world
0:22:03 > 0:22:05is hard.
0:22:06 > 0:22:10If you do find something, you want to make sure it doesn't escape.
0:22:12 > 0:22:14The praying mantis has arms
0:22:14 > 0:22:17that can strike ten times faster than a blink of the eye.
0:22:20 > 0:22:25And it's the only insect known to see in 3D.
0:22:26 > 0:22:29Perfect for judging strike distances.
0:22:35 > 0:22:37But like the chameleon,
0:22:37 > 0:22:41her problem is seeing prey when it freezes.
0:22:43 > 0:22:47She needs some movement to be sure it's food.
0:22:48 > 0:22:51Just the tiniest sign of life.
0:22:56 > 0:22:58Yep, that's done it.
0:23:03 > 0:23:07The lightning strike has given her the edge over her insect prey,
0:23:07 > 0:23:10but it doesn't pay to be complacent.
0:23:18 > 0:23:20In the jungle arms race,
0:23:20 > 0:23:24only too often there's someone else with a more powerful weapon.
0:23:29 > 0:23:31And there's one predator that has, perhaps,
0:23:31 > 0:23:35the most ingenious answer of all to the jungle's challenge.
0:23:37 > 0:23:41It lives along rivers in the rainforests of Madagascar.
0:23:43 > 0:23:47The insects it hunts fly down the same jungle corridors.
0:23:48 > 0:23:49But there's a problem.
0:23:50 > 0:23:53It's a web-building spider.
0:23:53 > 0:23:56So how does it get over the river to hunt?
0:23:57 > 0:24:00It's called Darwin's bark spider
0:24:00 > 0:24:04and the female has a remarkable strategy.
0:24:23 > 0:24:26Like a real-life Spider-Woman,
0:24:26 > 0:24:31she sprays strands of silk in one long, continuous flow.
0:24:35 > 0:24:37The threads fan out like a sail
0:24:37 > 0:24:40and drift on air currents blowing across the water.
0:24:42 > 0:24:45Every few seconds, she crimps the strands together
0:24:45 > 0:24:47to stop them spreading too widely.
0:24:50 > 0:24:52The breeze will do the rest,
0:24:52 > 0:24:57blowing the threads into a single line and a 25-metre bridge.
0:25:01 > 0:25:05Now she must reinforce her bridge, because her web will hang from it.
0:25:11 > 0:25:15But there's something bouncing the line at the other end.
0:25:15 > 0:25:20Another Darwin's spider is trying to take advantage of her hard work.
0:25:27 > 0:25:30She must deal with the intruder head on.
0:25:34 > 0:25:37The cut line is an inconvenience,
0:25:37 > 0:25:39but no more than that.
0:25:41 > 0:25:46With hooks on the tips of each leg, she gathers in the thread.
0:25:50 > 0:25:54It won't go to waste, as she'll eat it later.
0:26:01 > 0:26:05When it's all reeled in, she sprays again.
0:26:08 > 0:26:12Out streams another 25-metre bridging line.
0:26:20 > 0:26:22How a spider, no bigger than a thumbnail,
0:26:22 > 0:26:25can produce so much silk so quickly
0:26:25 > 0:26:27has baffled scientists.
0:26:31 > 0:26:34And it's no ordinary silk.
0:26:34 > 0:26:36It's the toughest natural fibre on the planet,
0:26:36 > 0:26:38tougher than steel.
0:26:40 > 0:26:44And it needs to be tough to span the wide river.
0:26:47 > 0:26:49With the bridge taut
0:26:49 > 0:26:51and the ground anchor in place,
0:26:51 > 0:26:53it's time to construct her trap.
0:27:06 > 0:27:10These spiders can build the world's largest orb webs,
0:27:10 > 0:27:12up to two metres wide.
0:27:15 > 0:27:18A few hours from the first spray of bridging line,
0:27:18 > 0:27:20the job is done.
0:27:24 > 0:27:26Now her strategy is simple...
0:27:28 > 0:27:30..sit and wait.
0:27:49 > 0:27:52And there's one final bout of silk production...
0:27:54 > 0:27:57..shrink-wrapping her food for later.
0:28:03 > 0:28:06Not all rivers provide their predators
0:28:06 > 0:28:08with a steady supply of prey.
0:28:09 > 0:28:12On the Grumeti River in Tanzania
0:28:12 > 0:28:15lives the planet's most patient predator.
0:28:19 > 0:28:21A Nile crocodile.
0:28:23 > 0:28:25Five metres long,
0:28:25 > 0:28:27700 kilos
0:28:27 > 0:28:29and very hungry.
0:28:30 > 0:28:34His last square meal was nearly a year ago.
0:28:40 > 0:28:44The river's other residents aren't food...
0:28:45 > 0:28:47..just a distraction.
0:28:48 > 0:28:50He is waiting for something bigger
0:28:50 > 0:28:53from over the horizon.
0:28:55 > 0:28:58But beyond the big croc's isolated river,
0:28:58 > 0:29:00there's still no sign of the migratory herds
0:29:00 > 0:29:02he depends on for survival.
0:29:10 > 0:29:13Other, smaller crocs are waiting, too...
0:29:14 > 0:29:19..but their meal ticket depends on the hunting skills of the big guy.
0:29:25 > 0:29:28The herds could be here in a week, or a month.
0:29:28 > 0:29:31In rare years, not at all.
0:29:33 > 0:29:37Until then, the crocs must conserve their energy.
0:29:58 > 0:30:01GRUNTING AND MOOING
0:30:01 > 0:30:05Finally, the sound they've all been waiting for.
0:30:11 > 0:30:13The herds have arrived.
0:30:22 > 0:30:25It's time for the crocs to get into position.
0:30:36 > 0:30:38All eyes will be on the big guy.
0:30:40 > 0:30:45Only he has the power to tackle a full-grown wildebeest.
0:30:51 > 0:30:54The year-long wait is almost over.
0:31:01 > 0:31:05After months on the march, the wildebeest are desperate to drink.
0:31:10 > 0:31:15But experience has taught the adults to be cautious.
0:31:22 > 0:31:25The water is just too inviting for a calf,
0:31:25 > 0:31:27unaware of the dangers within.
0:31:38 > 0:31:41But every wildebeest must take its chances...
0:31:43 > 0:31:46..and hope that its reflexes are faster
0:31:46 > 0:31:49than what many know lurks in the murky waters.
0:31:57 > 0:31:59Just a harmless hippo.
0:32:20 > 0:32:22That was no hippo.
0:32:26 > 0:32:29It's put the wildebeest more on edge.
0:32:35 > 0:32:39But here, fear always gives way to thirst.
0:33:07 > 0:33:10Catching the wildebeest is all about timing.
0:33:34 > 0:33:37The big croc's technique is rusty.
0:33:37 > 0:33:39It's been a whole year since his last hunt
0:33:39 > 0:33:41and he's out of practice.
0:33:46 > 0:33:51But this isn't the end of the drama, just an intermission.
0:33:52 > 0:33:54For the next two weeks,
0:33:54 > 0:33:57waves of wildebeest will pass through the Grumeti.
0:34:01 > 0:34:04Time for the big croc to try a different tactic.
0:34:07 > 0:34:09The floating log.
0:34:12 > 0:34:16He's hoping the wildebeest won't notice him until it's too late.
0:34:39 > 0:34:42Now the smaller crocs move in.
0:34:45 > 0:34:48The big croc will need their help to tear off chunks.
0:34:50 > 0:34:53Crocs can't chew, so they have to spin together
0:34:53 > 0:34:55to tear pieces off the carcass.
0:34:57 > 0:34:59Everyone gets their share...
0:35:00 > 0:35:03..and it's all thanks to the big guy.
0:35:05 > 0:35:10He won't feed again until the wildebeest return next year.
0:35:14 > 0:35:19Across the globe, millions of animals are continuously on the move
0:35:19 > 0:35:22in search of seasonal food.
0:35:22 > 0:35:25But it's not just prey animals that must migrate.
0:35:27 > 0:35:29Some predators have to journey, too.
0:35:36 > 0:35:41Amur falcons are one of the world's greatest long-distance travellers.
0:35:44 > 0:35:48As their prey dries up in their breeding grounds in Siberia,
0:35:48 > 0:35:53they embark on an epic migration to Southern Africa,
0:35:53 > 0:35:57crossing 14 countries, two continents and one ocean.
0:36:00 > 0:36:04Only here, in this remote valley in northeast India,
0:36:04 > 0:36:06do they join forces.
0:36:17 > 0:36:19A million falcons
0:36:19 > 0:36:22and the greatest gathering of birds of prey on the planet.
0:36:38 > 0:36:42This valley is a vital pit stop on the falcons' migration.
0:36:45 > 0:36:47The tiny raptors can go no further
0:36:47 > 0:36:49until they build up their fat reserves...
0:36:51 > 0:36:55..and they've timed their arrival here perfectly.
0:37:01 > 0:37:05For just a few weeks each year, winged termites, alates,
0:37:05 > 0:37:09leave the safety of their mounds in millions.
0:37:26 > 0:37:30High in calories, these alates are exactly what the falcons need
0:37:30 > 0:37:32to fuel their oceanic crossing,
0:37:32 > 0:37:36the longest made by any bird of prey.
0:38:00 > 0:38:03To have any chance of surviving their journey,
0:38:03 > 0:38:07they must nearly double their weight in just two weeks.
0:38:11 > 0:38:13Those that make it to South Africa
0:38:13 > 0:38:17will have to do the whole trip back again in four months' time.
0:38:19 > 0:38:21For Amur falcons,
0:38:21 > 0:38:26survival means flying 14,000 miles every year of their lives.
0:38:37 > 0:38:40For some predators, it's not the distance they have to travel
0:38:40 > 0:38:42that's their greatest challenge,
0:38:42 > 0:38:44but the size of their prey.
0:38:45 > 0:38:49And few challenges come bigger than the one in this ocean.
0:38:50 > 0:38:53Each year, female humpback whales
0:38:53 > 0:38:57journey from their feeding grounds in Antarctica to Australia
0:38:57 > 0:38:59to have their calves.
0:39:00 > 0:39:04These calm, warm waters are a perfect nursery.
0:39:05 > 0:39:08Perfect, but for one thing.
0:39:11 > 0:39:14Orcas, killer whales.
0:39:15 > 0:39:18They appear just as the migration begins.
0:39:19 > 0:39:21And they're on the hunt for calves.
0:39:23 > 0:39:28Highly intelligent, orca are the ocean's most successful predator.
0:39:31 > 0:39:34When hunting, they can travel at 30mph...
0:39:37 > 0:39:40..twice as fast as a mother and calf.
0:40:03 > 0:40:06The hunters close in silently.
0:40:12 > 0:40:17It's only now that the mother realises they've been followed.
0:40:17 > 0:40:19The orca have the advantage of numbers,
0:40:19 > 0:40:20but they need to be cautious.
0:40:22 > 0:40:26The mother's rear is protected by a five-metre-wide tail
0:40:26 > 0:40:28that could slice through them.
0:40:32 > 0:40:36Her flanks are defended by a pair of long, barnacle-covered flippers.
0:40:38 > 0:40:40And in the middle is the calf,
0:40:40 > 0:40:43riding high on its mother's back and out of reach.
0:40:44 > 0:40:46To separate mother from calf,
0:40:46 > 0:40:49the orca must use all their intelligence.
0:40:51 > 0:40:52They take it in turns
0:40:52 > 0:40:56to try and wave wash the baby away from its mother.
0:41:01 > 0:41:04In a month, the calf would be strong enough to withstand the onslaught.
0:41:06 > 0:41:08Not now.
0:41:12 > 0:41:15But then the tables are turned.
0:41:16 > 0:41:21A male humpback arrives, driving the orca away with its flippers.
0:41:29 > 0:41:33And the situation worsens when a second male appears.
0:41:34 > 0:41:39Now the pod face the power of three 40-tonne whales,
0:41:39 > 0:41:42and the escorts make their weight count.
0:41:51 > 0:41:55The bubbles are like a smokescreen,
0:41:55 > 0:41:58blocking the orcas' vision and sonar.
0:42:00 > 0:42:02There's a real danger of being injured
0:42:02 > 0:42:05by an unseen fluke or flipper.
0:42:17 > 0:42:20With the escorts defending both sides of the mother,
0:42:20 > 0:42:22the killer whales have been outmanoeuvred.
0:42:31 > 0:42:35As the orca retreat, the escorts drive home their advantage,
0:42:35 > 0:42:37pushing the hunters further away.
0:42:44 > 0:42:46It's an error of judgment.
0:42:48 > 0:42:50With mother and calf unprotected,
0:42:50 > 0:42:54the orca double back before the humpbacks can react.
0:43:16 > 0:43:19The killer whales separate the calf from its mother.
0:43:22 > 0:43:24They push the calf underwater
0:43:24 > 0:43:27and drown it.
0:43:33 > 0:43:37The intelligent hunters have turned defeat into victory.
0:43:44 > 0:43:49The orcas' prize is so large that sharks are quick to take advantage.
0:44:01 > 0:44:04Through intelligence, stamina and teamwork,
0:44:04 > 0:44:08the orca have mastered the ocean's greatest challenge.
0:44:09 > 0:44:13Yet even they fail as often as they succeed.
0:44:22 > 0:44:26Most predators fail most of the time.
0:44:27 > 0:44:30It's what makes them the hardest-working animals
0:44:30 > 0:44:32on the planet.
0:44:39 > 0:44:44The pressure is even greater when they have other mouths to feed.
0:44:51 > 0:44:53At eight months old,
0:44:53 > 0:44:57these cubs are still totally dependent on their mother.
0:45:01 > 0:45:05To support them she must kill something large, like a gazelle,
0:45:05 > 0:45:07nearly every day.
0:45:10 > 0:45:13But these youngsters are proof
0:45:13 > 0:45:16that she has overcome the challenge of their habitat.
0:45:19 > 0:45:24Few cheetah mothers get this far with four cubs.
0:45:39 > 0:45:41If the cubs are to survive without her,
0:45:41 > 0:45:43they must watch their mother carefully
0:45:43 > 0:45:48and learn the strategies for hunting on the open plains.
0:45:51 > 0:45:53There's a lot to take in.
0:46:14 > 0:46:16They'll need to learn
0:46:16 > 0:46:20that their top speed can only be sustained for a few seconds.
0:46:31 > 0:46:36They'll have to master how to match the twisting turns of the prey,
0:46:36 > 0:46:38so they get close enough to trip it.
0:46:58 > 0:47:02And they will soon learn the margin for error is tiny.
0:47:06 > 0:47:09The odds are against them.
0:47:15 > 0:47:1790% of cheetah cubs
0:47:17 > 0:47:20never make it to their second birthday.
0:47:23 > 0:47:26Even with this experienced mother,
0:47:26 > 0:47:29the future for this family is far from certain.
0:47:33 > 0:47:37All any predator can do is to keep on trying.
0:47:54 > 0:47:55For The Hunt team,
0:47:55 > 0:47:59filming a Nile crocodile capturing a wildebeest
0:47:59 > 0:48:03would require the same skill, patience and reactions
0:48:03 > 0:48:05as the five-metre reptile.
0:48:09 > 0:48:12The timing of the shoot would also be critical,
0:48:12 > 0:48:14since this behaviour only happens
0:48:14 > 0:48:18when the crocs' river is at its lowest point.
0:48:21 > 0:48:25But things get off to the worst possible start -
0:48:25 > 0:48:29the river in flood in the middle of the dry season.
0:48:30 > 0:48:32What we hoped for was that the Grumeti River
0:48:32 > 0:48:34would be just a series of pools
0:48:34 > 0:48:36full of crocodiles.
0:48:36 > 0:48:39They're probably scattered over 30 or 40 miles of river.
0:48:39 > 0:48:41So we've got to wait for two things -
0:48:41 > 0:48:43the crocs to bunch up and the wildebeest to come.
0:48:44 > 0:48:49As well as Mark, this small crew includes son Jacca
0:48:49 > 0:48:51and camerawoman and wife Vicky.
0:48:52 > 0:48:54Are you keeping watch?
0:48:54 > 0:48:57I am. I'm watching my son and my husband
0:48:57 > 0:49:01in a very deep, muddy river with lots of crocodiles!
0:49:01 > 0:49:04You could lose a large part of your family here if you're not careful.
0:49:04 > 0:49:06Yeah. Basically, half of us could be wiped out.
0:49:06 > 0:49:08These crocs hunt by stealth
0:49:08 > 0:49:11and they can sneak up in this dark, murky water
0:49:11 > 0:49:13right to the edge of the bank.
0:49:13 > 0:49:16So the golden rule of filming here
0:49:16 > 0:49:20is to be one metre from the water.
0:49:25 > 0:49:27Not to be outdone by the floodwater,
0:49:27 > 0:49:30the team sets up the first hide.
0:49:34 > 0:49:38But any idea of filming is soon swept away.
0:49:39 > 0:49:41Literally, within half an hour, an hour,
0:49:41 > 0:49:42I felt water around my ankles.
0:49:42 > 0:49:46If I was still in that hide, then he definitely wouldn't be on the bank.
0:49:46 > 0:49:48We're not going to go in and get it.
0:49:48 > 0:49:49The water the colour it is
0:49:49 > 0:49:52and knowing that he's got friends around,
0:49:52 > 0:49:54who could be literally just at the base there.
0:49:54 > 0:49:57With a flooded river and no wildebeest,
0:49:57 > 0:50:01the wait was going to be longer than expected.
0:50:01 > 0:50:02Crocs are used to being patient.
0:50:02 > 0:50:05But now we've got to show equal patience.
0:50:09 > 0:50:11Leaving the raging river,
0:50:11 > 0:50:15the team go in search of the migrating wildebeest,
0:50:15 > 0:50:19to see just how far they are from the Grumeti.
0:50:21 > 0:50:22I think we should go over the other side
0:50:22 > 0:50:24and then we'll get a sense of the number.
0:50:24 > 0:50:27- Should be up here. Do you want to take the controls? - I'll take the controls.
0:50:27 > 0:50:30It's some time before they find the wildebeest
0:50:30 > 0:50:33on the Serengeti's vast plains.
0:50:34 > 0:50:36- Loads there.- Loads?
0:50:36 > 0:50:38- Yeah, spread all the way across... - Oh, OK!
0:50:38 > 0:50:40Fantastic. How far away are we?
0:50:40 > 0:50:4270 miles away.
0:50:42 > 0:50:44Still a long way from the Grumeti,
0:50:44 > 0:50:48but at least the wildebeest were heading in the right direction.
0:50:48 > 0:50:51MARK TALKS INDISTINCTLY
0:50:55 > 0:50:57The wildebeest are still a long way away
0:50:57 > 0:51:00but, in the meantime, we can hopefully pick up
0:51:00 > 0:51:04these intimate moments with these really huge crocs.
0:51:06 > 0:51:08Finding the biggest and most dominant croc
0:51:08 > 0:51:11would be key to the team's success.
0:51:12 > 0:51:16Only the top croc would be powerful enough to grab a wildebeest.
0:51:18 > 0:51:20To find their star,
0:51:20 > 0:51:23Mark and Vicky would need to look out for territorial behaviour.
0:51:25 > 0:51:29Today it's sunny and it's early in the morning.
0:51:29 > 0:51:30I'm full of hope.
0:51:31 > 0:51:36But at the end of the day, all Mark sees is one static croc.
0:51:37 > 0:51:41He lay on the sandbank all day, I guess, seven hours.
0:51:42 > 0:51:44Urgh! Patience.
0:51:44 > 0:51:47And Vicky wasn't having much luck, either.
0:51:47 > 0:51:50When we first found it, there were crocs all over the bank over there
0:51:50 > 0:51:53and now I've been in here several hours and there's not one.
0:51:54 > 0:51:56After a week,
0:51:56 > 0:51:59Mark and Vicky are no closer to finding their dominant croc.
0:52:00 > 0:52:04But at least the news on the wildebeest was more positive.
0:52:04 > 0:52:0634 miles. Getting closer.
0:52:06 > 0:52:09Back on the river, it was like Groundhog Day.
0:52:10 > 0:52:12Crocs are all-or-nothing creatures.
0:52:14 > 0:52:16And I'm afraid it's been another day of nothing.
0:52:17 > 0:52:21With no sign of any action, the hours of watching motionless crocs
0:52:21 > 0:52:23were beginning to take their toll.
0:52:25 > 0:52:27It's like watching paint dry.
0:52:32 > 0:52:34Well, that was useless.
0:52:34 > 0:52:35Utterly useless.
0:52:37 > 0:52:39The crocs just didn't come.
0:52:39 > 0:52:42The team needed something to change
0:52:42 > 0:52:44and the falling water seemed a good omen.
0:52:45 > 0:52:48This is what the floodwaters left us - the lower jaw of a croc.
0:52:48 > 0:52:50And look at that. I mean, it's...it's heavy.
0:52:50 > 0:52:53This has come from a croc who must be at least five metres.
0:52:56 > 0:52:57And they're down there.
0:52:57 > 0:53:00Don't step too close to the water, sweetheart.
0:53:00 > 0:53:02I got too excited by the jaw!
0:53:05 > 0:53:06And with the water dropping,
0:53:06 > 0:53:10excitement was finally rising amongst the crocs.
0:53:16 > 0:53:18Well, that felt so different this morning.
0:53:18 > 0:53:21It really felt like there was an energy there...
0:53:23 > 0:53:25..that hasn't been there for weeks.
0:53:25 > 0:53:29And it isn't long before the team find their dominant croc.
0:53:29 > 0:53:34The big territorial male, who we hope will do most of the hunting,
0:53:34 > 0:53:36has been very active this morning.
0:53:36 > 0:53:39He's been displaying, really patrolling this stretch.
0:53:41 > 0:53:43With a big croc to focus on,
0:53:43 > 0:53:46all they needed now were the wildebeest.
0:53:48 > 0:53:52Mark and Vicky take to the skies to check on their progress.
0:53:52 > 0:53:54Look, right as far as you can see...
0:53:54 > 0:53:57- The crocs might actually get a meal. - That's great, Vick.
0:53:58 > 0:54:03The wildebeest were, at last, less than a day away from the Grumeti.
0:54:07 > 0:54:11Mark and Vicky take up positions on either side of the river.
0:54:11 > 0:54:14- WHISPERS:- We can see wildebeest
0:54:14 > 0:54:15just trying to come down,
0:54:15 > 0:54:18but they're just so nervous.
0:54:18 > 0:54:21After such a long wait, it's a tense time.
0:54:23 > 0:54:26Success for crew and croc
0:54:26 > 0:54:28will depend on split-second reactions.
0:54:40 > 0:54:44For the big croc, the first session ends in failure.
0:54:45 > 0:54:48It's very easy to have empathy for the animals that are being hunted,
0:54:48 > 0:54:51but I have to say that, in this instance...
0:54:53 > 0:54:55..my sympathies are all with the crocs.
0:54:55 > 0:54:58We've just seen how, over the past month,
0:54:58 > 0:55:00they've had nothing to eat at all
0:55:00 > 0:55:02and that's been what they've experienced for the last year.
0:55:05 > 0:55:10And it's a few days before the wildebeest return.
0:55:10 > 0:55:12It's 12 o'clock.
0:55:12 > 0:55:15Very hot, but I can hear the wildebeest again.
0:55:17 > 0:55:19There's a baby going in a bit further.
0:55:19 > 0:55:21Come on...
0:55:23 > 0:55:25Something's got to happen.
0:55:25 > 0:55:27Yeah, now he's right out there.
0:55:28 > 0:55:30Croc's right there next to him.
0:55:31 > 0:55:34Oh, God, you can see the croc underneath the surface.
0:55:34 > 0:55:37You can just see the swirl and just the dark shape.
0:55:37 > 0:55:39And there he goes! Oh!
0:55:40 > 0:55:41Urgh!
0:55:43 > 0:55:46And he missed him again.
0:55:46 > 0:55:48Yeah, at this time of the year, it's absolutely crucial for them.
0:55:48 > 0:55:51If they don't feed now, then they're in dire straits.
0:55:55 > 0:55:56Oh, here they come.
0:55:56 > 0:55:58Thirsty innocence.
0:56:01 > 0:56:02Come on, guys. That's better.
0:56:02 > 0:56:04Come on, you can do it.
0:56:04 > 0:56:09Got two there now, coming down on their knees next to them.
0:56:10 > 0:56:12Come on, you can do it.
0:56:12 > 0:56:15Just one footstep further out.
0:56:15 > 0:56:16That's all that croc needs.
0:56:17 > 0:56:19Oh, yeah, yeah.
0:56:19 > 0:56:20Go on...
0:56:20 > 0:56:21There he goes!
0:56:26 > 0:56:28Well, that was amazing. I mean, just...
0:56:28 > 0:56:31It suddenly happened.
0:56:31 > 0:56:34Trying to work out where the crocs were underwater was a nightmare!
0:56:34 > 0:56:36That was so intense.
0:56:36 > 0:56:38One minute, there was nothing.
0:56:38 > 0:56:41And the next minute, the bank was covered in wildebeest and then...
0:56:41 > 0:56:43one was taken.
0:56:46 > 0:56:48But I got it!
0:56:52 > 0:56:56Next time, the hunt is on in the frozen north,
0:56:56 > 0:56:58the High Arctic.
0:56:59 > 0:57:03One of the toughest places on Earth in which to make a living.
0:57:05 > 0:57:10To succeed here, a predator must exploit the few good times...
0:57:12 > 0:57:15..to endure the bad.