Nature's Great Events E03 - The Great Migration
Transcript
00:00The power of the sun drives the seasons, transforming our planet.
00:13Vast movements of ocean and air currents bring dramatic change throughout the year.
00:23And in a few special places, these seasonal changes create some of the greatest wildlife
00:29spectacles on Earth.
00:36One of the most awe-inspiring events takes place in the vast open plains of East Africa.
00:44Once a year, three million animals gather in a small corner of the Serengeti.
00:50This is the greatest concentration of grazing animals on the planet.
00:56But the herds only stay for a few months before continuing on their epic journey.
01:05And when the Great Migration moves on, the predators they leave behind become suddenly
01:10vulnerable.
01:12How can they survive until the Great Migration returns?
01:42The eastern edge of the Serengeti is dominated by a volcano known to the Maasai people as
01:53Ol Doinyo Lengai, the Mountain of God.
02:02It's one of the many volcanoes that have shaped the landscape here for millions of years that
02:08lie along Africa's Great Rift.
02:13To the west lie the grasslands of the Serengeti and a particularly fertile area known as the
02:19Short Grass Plains.
02:27For a few months each year, hundreds of thousands of grazers cram into this corner of the Serengeti.
02:36And of course, wherever you find grazers, you find predators.
02:46More meat-eaters hunt and scavenge on the Short Grass Plains than anywhere else in Africa.
03:01For lions in particular, this is, for the moment, a savannah paradise.
03:21With so much food on offer, it's a good time to raise young cubs.
03:29But lions are territorial.
03:32Each pride only controls a small area of grassland.
03:36They can only hunt the animals that come into their territory.
03:47So to give these cubs a good start, they'll have to make the most of this bonanza while
03:53it's here.
03:57When the great herds move on, the lions can't go with them, and prides like this one face
04:02a stern test.
04:06What happens next is a side of lion life that is rarely seen.
04:17It's May.
04:18The rains that water the Short Grass Plains have moved north, and the vast herds follow,
04:24seeking out fresh green pastures.
04:35Wildebeest are so in tune with the seasons that they can hear thunderstorms 30 miles
04:40away, and they home in on the scent of wet soil that carries the promise of fresh grass.
04:50Unlike lions, wildebeest are free to travel wherever the quest for food leads them.
05:04This young calf is at the start of an incredible seven-month journey.
05:19Without rain, the grasslands behind them wither and die.
05:25Within weeks, the Short Grass Plains start to turn brown.
05:34Within a few months, they're unrecognizable.
05:37Ninety percent of grazing animals have moved on.
05:41But a single wildebeest remains.
05:52It's now August.
05:53With so few animals here, the Short Grass Plains are no longer a great place to be a
05:58lion.
06:03For the lion pride living at the southern edge of these plains, in a place known as
06:08Ndutu, the test now is to survive until the herds return again.
06:18The Ndutu pride has four lionesses and seven cubs, and already they're struggling to find
06:24enough food and water.
06:30The youngest are weak and underweight.
06:46Surrounded by other lion prides with their own territories, the Ndutu pride must make
06:52the most of what they can find here.
07:00But there isn't enough food for them all.
07:03This male cub is not only hungry, he's sick.
07:16On this morning, the pride is heading for a woodland where there is more cover and more
07:22animals to hunt.
07:28It's a long journey for the exhausted cubs.
07:42For the weakest male, it's a real struggle to keep up.
07:47He's trying, but slowly he gets left behind.
08:02This is a brutal world.
08:04The lionesses simply cannot wait.
08:06If they don't keep hunting and eat soon, they too will become weak, and then there'll be
08:12no hope for any of them.
08:31Warthogs are a valuable catch at this time of year.
08:37The lives of the cubs depend on a successful outcome, while one lioness slowly creeps forward.
09:21It's been a while since their last kill, and all the hungry pride pile in.
09:31All, that is, except one.
09:46A mile away, a young life is fading away.
09:52The kill has come too late for him.
09:56At less than a year old, these cubs are still totally dependent on the lionesses.
10:07To survive, they must keep up.
10:14Only three months into the dry season, the undutu pride is down to six cubs.
10:21Sadly, this young male will not survive.
10:43It's late August, and the rains are still moving north, taking the grass and the wildebeest
10:50even further away from the undutu lions.
11:05With no territory to enclose them, the wildebeest can travel wherever they like, but a calf,
11:12just like a lion cub, still has to stick close to mum.
11:28The biggest danger is getting lost in the vastness of the herd, as it treks up to thirty
11:33miles a day.
11:59Back at undutu, the dry season is biting harder.
12:04There's little grass here, but that's not a problem for some.
12:20Giraffe find most of the nutrients and moisture they need in acacia leaves, and like impala,
12:28they can cope well in the dry season.
12:37Serengeti mice positively thrive in the drier months, thanks to the abundance of seeds,
12:43so some of the smaller predators, like wild cats, still find plenty of food.
12:53This kitten is unlikely to go hungry.
13:10Perhaps surprisingly, it's the creature often called the king of the beasts that is suffering
13:15the most.
13:22It's early September, and on this afternoon, there are only two male cubs with the undutu
13:28lionesses.
13:30And they're little more than skin and bone.
13:36What's happened to the rest?
13:40Sadly, it seems others have been left behind.
13:52One young female cub is just two miles away.
13:56She's limping, and the black patches on her face reveal that she's losing her fur.
14:08But she hasn't given up.
14:09She calls for her pride.
14:19She hears a faint call and hurries towards it.
14:27And is reunited with one of her brothers.
14:42Nearby there is prey, but these cubs are unable to hunt.
14:47They're still too young.
14:51If they're going to survive, they must rejoin the pride.
15:03While she still has strength, she continues to try and make contact.
15:19Far away, the lionesses also call constantly and listen for their lost youngsters.
15:35Then a sick cub joins in the search for his sisters and brothers.
15:52But there are no replies.
15:54After an hour of calling, the lionesses can wait no longer.
15:59They must move on.
16:07The pride will have to move to another part of their territory if they are to find food.
16:17None of them have eaten for days, and now the chances of being reunited with the lost
16:23cubs seems remote indeed.
16:39It's September, one of the driest months in Ndutu.
16:44The wildebeest herds are over a hundred miles away, having followed new pastures to the
16:49northern edge of the Serengeti.
16:53But they have a huge challenge of their own to face.
16:58They must cross the Mara River.
17:13Over several days, the herds crowd together at the water's edge.
17:22The adults seem to sense a hidden danger.
17:31But the numbers keep piling up on the river's edge, and ultimately they face the danger
17:35together.
17:49The crocodiles are spoilt for choice.
17:55And they can only take one victim at a time.
18:22There is safety in numbers here, and most of the wildebeest make it across to the grasslands
18:29beyond.
18:38Back in the south, the Ndutu plains are tinder dry.
18:50Wildebeest and insect eaters can scratch a living, and the smaller cats like Serval
18:55that hunt them can still find plenty to eat.
19:04And a cheetah mother is managing to keep her cubs fit and healthy on the small antelope
19:09that remain.
19:27It's now October, the peak of the dry season, and the Ndutu pride are resting in the heat
19:33of the day.
19:36In a bizarre twist of fate, one of the two male cubs has died.
19:41But amazingly, the lost female with the black face patches has found her way back.
19:56She's still weak, and clearly hasn't eaten for days.
20:03Meanwhile, it's getting hotter.
20:13Just when it seems life couldn't get any worse, it does.
20:34Flames race across the Ndutu pride territory, burning the last of the grass and any remaining
20:40bush cover.
20:49At
21:18first glance, there's little left here, yet animals like Impala quickly return to investigate.
21:28The Impala's world has changed beyond recognition.
21:33There's nowhere left to hide.
21:38The Ndutu pride has also lost the cover they use for hunting.
21:46The young female may have survived her first fire, but her chances of a meal have fallen
21:51even lower.
22:05For the cheetah family, the fire is not such bad news, as their prey can actually become
22:12easier to find.
22:19The steenbok relies on blending into its surroundings and sitting still to avoid being
22:24spotted.
22:27But in this emptiness, its camouflage is useless.
22:33It's a sitting target, and apparently unaware of the approaching danger.
22:53It's a sitting target, and apparently unaware of the approaching danger.
23:20Larger prey, like Grant's gazelle, are constantly on the lookout for danger, and easily see
23:33the Ndutu pride in the distance.
23:39The task for the hunters now seems virtually impossible.
23:53But they do have one advantage.
23:55There are four lionesses, and they've been hunting together for years.
24:06It will be hard to get close to the warthogs.
24:13But if they can split up and attack on two sides, they may stand a chance.
24:22This is how a young lioness learns.
24:34As ever, teamwork is critical.
24:57In a well-practiced routine, a lioness moves round to block the warthogs' escape.
25:23As one is flushed into the open, the flanking lioness rushes in for the kill.
25:44Warthogs are a favourite food.
25:47It's a welcome feast enjoyed by all.
25:51At the toughest of times, the lionesses have provided for the cubs.
26:01But it's an unpredictable year in more ways than one.
26:10For the first time in 40 years, the sleeping mountain of God, Ol Doinyo Lenggai, awakens.
26:32Vast clouds of volcanic ash drift towards the short grass plains and the home of the
26:51Ndutu pride lions.
26:59Ravaged by fire, scorched by the sun, the plains now become shrouded in a layer of ash.
27:18It's November, and the rains that would bring the return of the grass and the herds are
27:23now overdue.
27:32The Ndutu lionesses rest in the intense heat, and the cubs' batteries are now running very
27:38low.
27:43But the winds are changing, a sign that the season is turning.
27:59The wildebeest seem to know what's about to happen.
28:03They begin heading south.
28:07One and a half million wildebeest start their journey back to the short grass plains.
28:30The great migration of the wildebeest is one of the longest treks of any land animal on
28:35our planet.
28:36As they follow the rains around the Serengeti, many will travel over a thousand miles.
28:49But there's no guarantee that these wildebeest will return to the territory of the Ndutu
28:54pride.
29:00They will feed only where the best grasses grow.
29:07All that's needed now is rain.
29:52For the Ndutu pride, rain brings hope, but how long will it take for the grass to grow
30:16and the herds to return?
31:16Within a matter of days, fresh grass transforms the arid plains into the lush pastures that
31:30will lure the herds to return.
31:41It's December, and the migrating herds start to arrive at the northern boundary of the
31:46short grass plains, just 30 miles from the Ndutu lines.
31:58After seven months away, the herd is returning.
32:26Stretching back some 25 miles, it will take weeks for all the wildebeest to arrive.
32:48And nothing will stop them now.
33:06The mountain of God chooses this moment to throw up a column of ash 50,000 feet into
33:14the air.
33:24But the link between this ash and these herds is more than a mere coincidence.
33:37For this ash is rich in minerals, and over several million years, as volcanoes in the
33:44Great Rift have erupted, layer upon layer of ash has fertilized the ground, creating
33:51this uniquely fertile grassland.
33:56It's this that draws animals from all over the Serengeti.
34:07The ash also discourages the growth of trees, so on these plains that might otherwise be
34:13covered in woodland, little grows except grass.
34:26It's possibly the best grazing land in all of Africa.
34:36And probably the only place where one and a half million wildebeest could feed together.
34:54In the northern half, the short grass plains have once again become a savannah paradise.
35:15The conditions are so good that the wildebeest also use these plains for another important
35:22purpose.
35:26The females are carrying the next generation, and they've come here to calve.
35:43It only takes seconds.
36:02Some calves are on their feet in just two minutes.
36:10Others take a little longer.
36:24Then they're good to go.
36:37Grass and calcium in the volcanic ash pass through the grass, into the mother's milk,
36:43and into the growing calves.
36:47Nowhere else on their epic journey could young wildebeest get such a good start in life.
37:04In just two to three weeks, over half a million wildebeest calves are born here.
37:13And of course, this provides an irresistible opportunity for all of Africa's top predators.
37:23This is boom time for meat eaters.
37:29The Ndutu lions to the south have yet to enjoy this feast.
37:34But this cheetah family now has an endless supply of fresh meat.
37:50It is certainly enough to feed the six cubs.
38:20She'll make a kill every day to keep her cubs properly fed.
38:45And it's not just wildebeest the predators have come to eat.
38:51Many of Africa's antelope are here too.
38:56Eland, Africa's largest.
39:02And they're joined by more than half a million Thompson and Grant's gazelles.
39:10200,000 zebra.
39:20Just north of the Ndutu lion territory, these lions are now lucky enough to enjoy a time of plenty.
39:30Her favourite lion ploy is to wait by waterholes,
39:34knowing that the herd will ultimately have to drink.
40:31As the herds move further south, they at last enter the homeland of the Ndutu pride.
40:39The question is, have the weak cubs managed to survive to witness the great return?
40:57The Ndutu pride is still together.
41:00They're healthy and strong.
41:06Somehow they've managed to make it through the long dry season
41:10and the endless wait for the returning herds.
41:15The young male now has the beginnings of a mane.
41:20And though still limping, the female has grown new fur over her black patches.
41:42Now at last with endless food around them,
41:45the lion cubs have the time and the energy to play.
41:57And they can relax in a way that only lions know how.
42:15By March, the great event on the Ndutu plains is in full swing.
42:27And where there are kills, there are scavengers.
42:32Vultures fly in from all over the Serengeti.
42:46On her own, a mother cheetah has little chance of keeping this mob off her kill.
42:58She may be agile, but she lacks the necessary brute force.
43:04Even now, it's not easy raising cheetah cubs.
43:08Over half her kills will be stolen by thieves.
43:15Spotted hyenas are notorious scavengers and they arrive in force.
43:29Hyenas now become the most numerous carnivores on the Ndutu plains.
43:35They'll even take on a lion pride.
43:45As the Ndutu lions finish off a wildebeest,
43:49the hyena clans gather around, trying to intimidate them.
44:04The young male cub faces up to them.
44:08He's finally coming of age.
44:10He's learning how to protect a pride.
44:28But this time, with their bellies full, the pride decide the bones aren't worth the hassle.
44:40Well-fed at last, the two young cubs are beginning to look more like adults.
44:52But it will be another six months before they can hunt on their own.
45:00It's April and there's a flurry of excitement as the wildebeest turn their attention to courting.
45:16Or at least the males do.
45:30The young bulls limber up for the rut when they will have to fight for the right to mate with a female.
45:46High spirits are infectious.
45:58In three months, the young calves become boisterous and bounce with good health.
46:16These planes have been a nursery.
46:26But change is in the air.
46:30The season is turning again.
46:34The arrival of seed-eating quila is a sign that the grass on the Udutu plains is changing.
47:04Once the grass flowers and sets seed, it loses the succulent green leaves that the wildebeest prefer.
47:28Time for them to move on again.
47:32To follow the distant storms that are now rumbling to the north.
47:42Despite the arduous journey that lies ahead, a wildebeest calf in the Serengeti still has a better chance of surviving its first year than a lion cub.
47:58The great migration is leaving Udutu.
48:02And once again, the pride will have to face life without the herds.
48:10A brother and sister have survived an eventful year that has brought sickness and drought, fires and volcanic eruptions.
48:22Theirs is just one of countless stories that unfold every year on the short grass plains.
48:30The grasslands at the centre of this great event.
48:36All in the shadow of the mountain of God.
48:53To film intimate animal stories in the vast Serengeti was the toughest challenge faced by the great migration team.
49:02Especially when a major part of the mission was to follow the fortunes of a single Serengeti lion pride.
49:12For filmmaker Owen Newman to tell the full story of a pride, he had to follow them before and during the annual wildebeest migration.
49:28The filming would take seven months. A rather long time to be stuck in a rather small car.
49:36There's just one tiny space in here where I can move and it's the bit for using these pedals for steering with and for being able to turn round like that and operate the camera.
49:48That's the only moving space I have in here.
49:52So, I mean, every day for 14 hours, that's it.
49:57But out of here is this phenomenal view on the world and all the animals that are out there.
50:04I wouldn't swap it for anything.
50:07If Owen was to stand any chance of keeping up with his lion pride, he would have to cover thousands of miles alone in his cramped car.
50:18Owen has filmed many lion stories, but not even he could have known how dramatic and harrowing the story of the pride's youngest lioness would become.
50:31The drama started in the dry season when Owen first found the lions known as the Ndutu pride.
50:41The cubs were already suffering and even with 20 years experience of filming big cats, for Owen, these scenes were hard to witness.
50:52And I was so appalled with the condition that the cubs were in.
50:57They were all around a year old and I'd never, ever seen lions so thin as they were.
51:04It was absolutely shocking.
51:08As the litter of seven cubs dwindled to only four, the drama continued to unfold.
51:14Just as the dry season dragged on, they got manged, the skin was falling apart.
51:20The little female in particular had looked as though she had no chance.
51:26One awful day, Owen found that more cubs had been left behind by the pride, the little female and a brother.
51:34Hungry and alone, their death seemed inevitable.
51:38Quite late in the afternoon, but earlier than I would have done ordinarily, I left because it was actually getting to me so much I couldn't stand being there.
51:48It was really so sad.
51:53I went back the next day and there was no sign of either of the cubs and I just assumed that probably they had died.
52:02Amazingly, in a dramatic twist, the little lioness did survive and rejoin her family.
52:10But when the rains came, the whole pride disappeared.
52:21As filming resumed at the start of the wet season, all eyes were on the lookout for the Ndutu lions.
52:32Although the plains were now teeming with animals, what Owen really wanted was to find his lion cubs.
52:42All he could do was to sit, watch and wait.
52:48This is what happens for hours on end.
52:52Nothing.
52:54Nothing.
52:58With spotters continuing the search for the Ndutu pride, Owen got on with filming the great migration of the wildebeest and its newest recruits.
53:11What's really nice about the calves being born is for about eight months, while they've been developing,
53:17they've been carried around by the mums across the plains, they've been stampeded by hyenas and lions,
53:26they've criss-crossed crocodile-infested rivers, and here they are, being born to join in.
53:41It never fails to be a really wonderful thing to see.
53:47When the calf's born, and the mother gets up and starts licking it, and the little thing tries to stand up on incredibly wobbly legs,
53:56and within two minutes, is walking away with his mum.
54:04Oh, look, it's nearly found the udder.
54:09With shots of wildebeest calving in the can, Owen could get on with his search for the lion cubs.
54:16The lion's story was still hanging in the balance.
54:20All Owen could do was persevere with his daily filming routine.
54:28Do you think it's breakfast time?
54:45That is a good cup of tea.
55:03Another month had passed, and even with Owen's years of experience, the fate of the Udutu pride lions was still a mystery to him.
55:12To recognise them, Owen had photographs of their whisker patterns.
55:17They're as unique as a fingerprint.
55:21If only he could find them.
55:28Jeez, there's no peace. I'm stalked.
55:33Okay, well, it's a low moment, I have to admit.
55:38Time seems to be dragging. We need to be doing something.
55:42We can't just be sitting here admiring every small bird that hops by.
55:57Then, one morning, a report came in from spotter Hamisi Masawe, who had found a group of lions matching the Udutu pride's description.
56:08Over there.
56:10Over there. What a place to be, Hamisi.
56:13And there were two cubs.
56:15Yeah.
56:16Yeah, okay.
56:17And the male, there's not much male.
56:21On the cub?
56:22Yeah.
56:23Yeah, he's just got a little lion.
56:24Do you know what lion is?
56:25Yeah, yeah.
56:27Finally, after months of worry and total dedication,
56:31Owen would discover the fate of his thin female cub, the one with the black face patches.
56:37Had she managed to survive?
56:43The news was good.
56:47Yeah, she's my favourite.
56:50Of course, by all rights,
56:54I think she should be dead from what I saw in the dry season.
56:59But here she is, still alive.
57:09Wow. She's still got a tiny limp on her front right foot,
57:13but otherwise is in really good shape.
57:19Wow.
57:23They're so friendly.
57:27Oh, such a fantastic day.
57:37And they're all playing together as well and reacting, which they never did in the dry season.
57:42It's absolutely wonderful.
57:50Oh, they've turned into proper lions.
57:55You can spend a long time in the Serengeti,
57:58and they're all fantastic days, but suddenly you get a day like this,
58:02which is absolutely fantastic.
58:07For the healthy cubs, it was just another day in the short grass plains.
58:12For Owen, a wonderful moment within the most harrowing lion story he had ever filmed.