The Great Wildebeest Migration in Serengeti

The great Migration of the Serengeti is considered one of ‘The Ten Wonders of The Natural World’, and one of the best shows in the wildlife world to witness. This is the nature’s greatest show and one of the most mind-boggling wildlife phenomena in the world.

The extraordinary movement of almost 2 million hooved beasties is a year-round cycle. So whether you want travel in February or August, watch thundering river crossings or the magic of calving season, there’s a right place and a right time to visit Tanzania.

What makes a million wildebeest get up and move at once? What is the sense that triggers them to muster the energy to begin a 1000-kilometre trek—to somehow know that it’s the right thing to do? This is the story behind the great wildebeest migration (Story extracted from Paul Steyn posts – The Wildlife blogger).

March – May

It’s mid March in the northern Tanzania, and thousands of animals are happily milling on the rolling plains of the Serengeti. The female wildebeest have just dropped their calves in a beautiful display of new life, as the youngsters stumble and stagger to their feet and are up and running within minutes. There’s still plenty of food to go around, and life must seem pretty idyllic for the wildebeest.

And yet, one, or two, or maybe a few hundred wildebeest sense something in the air.

For some reason, a few animals decide to start moving. They just get up and go, and the rest begin to follow.

Just like that: the largest terrestrial mammal migration on earth has begun.

It is a trek, a round trip, of some 1000 kilometers, over two countries (Tanzania and Kenya), across plains where predators—lion, cheetah and leopard—wait to pick off them off, over hills, and through rivers with crocodiles waiting; battling disease, starvation, thirst and fatigue; with around 250 000 animals perishing along the way.

Despite all this turmoil ahead, without fail, they go.

Why do they do it?

Why, when most wildebeest in Africa are non-migratory, do the animals of the Mara/Serengeti ecosystems risk it all in one mad trip?

No scientist or naturalist has yet been able to answer this question conclusively. But there are some theories.

Studies using aerial photography show a remarkable level of organization in the structure of the wildebeest herds as they start moving. The groups display a wavy front that snakes out like the head of a swarm. This amazing structure cannot be apparent to each individual wildebeest, which means that there is some degree of decision making that is happening between the animals. Is there some sort of leadership being displayed; maybe a form of communication we don’t yet know about?

Some scientists believe that the wildebeest are motivated by the chemistry of the grass. The herds are attracted to higher levels of phosphorus and nitrogen, which changes in response to the rains. So perhaps the wildebeest are merely following their taste.

It might simply be instinct. Fossil evidence suggests that wildebeest have been roaming the plains of East Africa for over one million years. In the same way their body tells them to run when a lion appears out of the grass, maybe the instinct to migrate has been coded into the DNA of the animals over many years of evolution.

Perhaps they just know—and so they just go!

Whatever the reason, over 1.5 million animals begin a journey that will undoubtedly cause death to many of their own, but will also bring life to many more animals as they follow the rains in search of green nutrient-rich fields that will sustain the next generation.

And so they charge onwards.

What Actually Happens?

During March the last of the babies appear and the wildebeest continue to nibble on the luscious grass. Following the localized rain showers, the wildebeest move across the Southern plains in search of the juiciest shoots and can wander as far as the northern reaches of the Ngorongoro (but never into the crater itself). Hungry predators follow their every move… The Southern Serengeti makes the best place to stay during March

The great migration continues to move constantly in April. Feasting complete and leaving behind a rather barren landscape in the south, the herds follow the rumblings of thunder northwards. Mega columns of wildebeest stretch from the south, through the Moru Kopjes in the central Serengeti and all the way to the Western Corridor.

During May, a few rogue wildebeest head even further north of the central region, but the masses make their way across to the Western Corridor. Here, they congregate in their heaving hundreds of thousands on the banks of the Mbalageti and Grumeti rivers and the first real challenge of the trek awaits: how to get to the other side…

By June, the herds begin to spill across the murky pools of the Mbalageti and Grumeti rivers. Although not quite as dramatic as the northern crossings, there’s plenty of drama in store as the crocodiles prepare for their annual wildebeest-banquet. Rutting season is also underway and the plains are alive with testosterone-fuelled males chasing their chosen ladies.

June – September

It’s mid July, and the herds have been trekking across the duvet plains of the Serengeti for over three months.

The animals are tired, hungry, and thousand have been lost to predators, disease and fatigue. By this point in the journey, the wildebeest are probably wondering what they have done; and why on earth they should keep going.

But before it gets any easier, it’s going to get harder.

Before they can reach the lush Masai Mara grasslands, they must overcome one last obstacle — the rivers!.

The throngs of animals amass in their thousands on the banks of the great Grumeti and Mara Rivers, and they wait. They build up their courage, energy, and motivation. It seems as if they will never do it, as if this is too large a barrier for them to cross. But in the same indescribable way that the trek began some 4 months earlier, one courageous wildebeest makes the first move—the first jump. They pour into the rivers like ants, leaping, bleating, calling—a crescendo of adrenaline and instinct.

One interesting study likened the wildebeest migration to a type of ‘swarm intelligence’. From the outside, the crossings seem to be frenzied and uncalculated—almost like mass suicide—but the animals are, in fact, systematically exploring and overcoming the obstacle as one single unit – or swarm.

What Actually Happens?

By June, the herds begin to spill across the murky pools of the Mbalageti and Grumeti rivers. Although not quite as dramatic as the northern crossings, there’s plenty of drama in store as the crocodiles prepare for their annual wildebeest-banquet. Rutting season is also underway and the plains are alive with testosterone-fuelled males chasing their chosen ladies.

During July the survivors continue to the northern Serengeti. The treacherous waters of the Grumeti may be behind them, but worse is in store in the shape of the great Mara River. The river itself winds through the north-western Serengeti before twisting into the western Masai Mara in Kenya and viewing is good in both countries. Depending on rainfall, the crossings can begin as early as June or as late as August.

By August, the river crossings are well underway. Plunging into the waters of the Mara River, the wildebeest must survive the snapping jaws of the Nile crocodile before dodging the lion lying in wait on the other side. Marabou storks and vultures flock to the river to feast on the fallen and game viewing is dramatic, bloody, frenzied and sensational. (Bookings for this season must be done early in advance)

After the drama of the river crossings, some of the beasties will remain contentedly in the northern Serengeti but most will make their way to Kenya’s Masai Mara. On the lookout for fresh grass (they need it after those crossings!) the herds will wander all over the place, crossing and re-crossing the dreaded river and facing predators wherever they turn.

October – November

It’s nearly October and most of the rumbling herd has made it across the Grumeti and Mara Rivers.

The wildebeest migration, they are tired and frightened, they congregate on the vast carpet plains of the Masai Mara, where new, nutrient-rich grasses spread out as far as the horizon. It must feel like heaven to the animals.

They have arrived.

After such a long journey, one presumes that the wildebeest might wait and enjoy the spoils of their trek. Or perhaps just stay for a while.

But as November begins, the storm clouds gather in the distance, and the wildebeest sniff the air, kick the ground, and stir.

They circle round the eastern fringe of the Mara, braving the mighty Mara River once more, and then head back to the final straight of their journey. They trek through western Loliondo and the Serengeti National Park’s Lobo area, returning to the green shoots which follow the rains on the short-grass plains of the southern Serengeti.

What Actually Happens?

By October, most of the herds will begin making their way back south through the Serengeti, answering the call of the rains in their search for juicy new grasses. Some unlucky animals may still have a river crossing to face, but they become fewer as the month passes. And of course, the hungry predators are still hot on their heels.

The herds continue toward the Southern Serengeti in November, the journey becoming more urgent as the rains begins to fall with fervor – they must reach the southern plains of Serengeti as soon as the first grasses begin to sprout. Eastern Serengeti and central Serengeti – Seronera region become the best wildebeest watching place during this season.

December – February

It’s now December, and the weary herds are arriving in the southern Serengeti after their epic year-long trek.

The mother wildebeest are heavy with pregnant bellies, and as soon as they are settled, the calves drop on the fresh grass. In minutes, the wonky-legged calves are up on their feet, somehow sensing that they need to be strong and independent soon.

Why? There are predators lurking, and the youngsters know they have a long journey ahead.

What Actually Happens?

And it’s back home! The majority of the herds has reached the Southern Serengeti plains by December and is rewarded with those all-important new shoots. Feasting begins, the predators come out to play and the cycle of life begins again….

In January, the herds of wildebeest congregate to munch on the newly-sprouted grasses of the Southern Serengeti around Lake Ndutu and Kusini. Following the rains in November and December, the plains are covered in a thick carpet of juicy green grass – a nutritious feast for the discerning gnu.

After a month of devouring nutrient-rich grass, the female wildebeest prepare to give birth on the southern Serengeti plains. Between late January and March, over 500,000 calves are born (that’s 8,000 every day!) and gangly babies dot the landscape. A heart-warming spectacle, but similarly heart-breaking as the predators line up for their fill of easy prey…

The Southern Serengeti will be your best choice of place in this season.