The annual wildebeest migration, across the Serengeti, in Tanzania, and parts of the Maasai Mara in Kenya, is the largest migration of land animals on the planet. An average of 1.5 million make the 1,000-mile circular journey every year. And though the wildebeest are the star, they are accompanied by more than 350,000 gazelle, 200,000 zebra as well as thousands of eland, antelope and impala. Herds stretch 25-miles long, filling the entire horizon. Galloping hooves kick up the dusty ground into a storm of earthen mist. The ground shakes. The noise is like thunder. This is Africa’s great migration. Seeing it is, perhaps, the greatest wildlife spectacle on Earth.
“An average of 1.5 million make the 1,000-mile circular journey every year”
But the journey is hard and fraught with danger. The story begins on the slopes of the Ngororngoro Crater in the southeastern corner of the Serengeti Plains. Between January and March the wildebeest cows give birth to their young in near perfect unison. Within three weeks more than 300,000 calves will be born. Dozens of lions and hundreds of hyenas stalk the peripheries of the herd, looking for easy prey. But such abundance satiates the predators and ensures the maximum amount of young will survive. The newborns are also highly adaptive, gaining co-ordination faster than any other ungulate. Within two minutes a newborn calf is on its feet. Within five it can run with the herd.
By the end of March the short-grass of the southern Serengeti is wearing thin and the wildebeest begin their journey west in search of food. Their movement is triggered by an awareness of environmental factors. They are sensitive to changes in atmospheric pressure and humidity, allowing them to sense the onset of distant rain, and on the horizon thunderclouds begin to bellow, providing a visual stimulus too. Where the rains are, grass will grow; and so they move.
And they are built to travel. 3,000 lions, 1,000 leopards, 300 cheetahs, packs of wild dogs and untold hyena await them. But they are ready. A fully grown wildebeest is 8-feet in length, 600 pounds and able to run at 40mph. They have evolved to cover long distances quickly and economically. And while predators are confined to small territories and sprints, the herds can keep up a steady pace and simply blast through.
As the rains set in, the herds travel northwest through woodland and low hills toward Lake Victoria and the plains of the Serengeti’s western corridor. Here, in May and June, usually at a full moon, the rut begins, accompanied by vicious fighting between dominant males.
Then they head north, towards fresh grass into Kenya and the Maasai Mara Game Reserve. But to get there they face one of the greatest obstacles of their entire journey: rivers. For most of the year the Mbalangeti and the Grumeti Rivers in the Serengeti and the Mara River in Kenya are placid. But sudden rainfall can create violent torrents. It is not uncommon for 5,000 wildebeest to drown in a single crossing if the conditions are unfavourable. But that’s the least of their problems. Waiting beneath the depths are giant Nile crocodiles, 14-feet long with jaws that can snap a neck in seconds.
But the promised land is on the other side. During the course of their migration 250,000 wildebeest will die in order to make it to the lush grasslands of the Maasai Mara – from predators, thirst, starvation and just pure exhaustion. Once there the giant herds spend months feeding and fattening up. But by late October, as the first rains begin to hit the distant Serengeti, once again filling seasonal waterholes and flushing the ground with grass, they begin to close the circle. The herd treks south, cows heavy with the new season’s young, back to where they started, on the slopes of the Ngorongoro Crater. Here they feed, wait for their young to be born and watch the horizon for thunderclouds to light up the sky once more.
In reality there is no single event of the migration. The wildebeest are the migration: a constant movement across the plains of Africa, chasing rainbows in search of food. Their movement is the lifeblood of the plains, cropping grass, fertilizing the land and providing vital protein for predators. They face many obstacles, but now there is a new threat too. East African population booms have resulted in development pressures, deforestation, poaching and habitat fragmentation. Climate change is causing more intense periods of rain and drought. All this threatens the clockwork balance of life. And the great migration is the keystone of the entire ecosystem. If the wildebeest should fall, the Serengeti will fall with it. This may be the greatest wildlife spectacle on Earth, but it’s also one of the most vivid examples of the interconnectedness of life. Everything depends on everything else. There is no migration in its singularity. Only a dance; a symphony with different players and many parts. Africa’s great migration is the music of the planet itself.
Serengeti National Park, Tanzania and Maasai Mara National Park, Kenya
How to See it
Time your visit with the migration cycles of the Wildebeest, but cross your fingers too: the exact dates of the migration are dependent on the rain and vary each year. July – October is generally the best time to go to Kenya. January – March is calving season around the Ngorongoro Crater, in Tanzania. While April – June the herds travel through central and western Serengeti. www.serengeti.org, www.magicalkenya.com
The Mara River crossing is probably the most spectacular event of the entire migration. Come between July and November for the best chance of seeing it, but you’ll need patience and luck. If you can afford it, stay in a private game reserve just outside the National Parks boundary where there are less crowds and more intimate wildlife encounters. Or even better book a private mobile camp, which follows the herds.