You really have to see it to believe it. The migration of the wildbeeste from the Serengeti National Park in Tanzania, northward into the Masaai Mara Reserve in Kenya, is one of Africa's great nature spectacles.
At present some 2 million wildebeeste (probably gnu to you) are moving in four or five columns across the great plains of East Africa. From the air it is an amazing spectacle. It is even more spectacular from a car or truck -- which may be held up for an hour or more while a column of 10,000 or more gnu pound across the trail in an unbroken line.
Nobody knows how long ago the annual migration, which takes place between August and September, began. But it is likely to go back a long way in a continent where patterns of animal life sometimes seem unchanging.
The Serengeti gets dry and parched about this time and the gnu make for the lusher grasses of the Mara, where there is plenty of water to provide good grazing.
But did the gnu get it all wrong this year?
Wild life experts say the good rains in Serengeti produced fine grasslands for gnu grazing.
There was no need for the gnu to make this 200-mile trek, facing appalling dangers from lion and other predators, with female gnu giving birth on the way, only to have their baby calves snapped up by hungry beasts and birds.
Yet they went, possibly answering a command from deep-seated instinct, or possibly the "Great Gnu" to find "the greener grass on the other side."
The gnu (wildebeeste in Africa) is an unattractive animal. He has a huge head, with a little beard, a short body, and horns nobody would be seen dead with on a library wall. Hunters never haunted him. His meat is tasty only to lions. The comedian of the animal world, he permanently switches his tail, and jumps round the bush. On his annual migration nothing can stop his onward march , which is often undertaken at a gallop.
The way to the greener pastures is fraught with dangers. Waiting lions knock them off as they go, and there is no hope for the slow, the lame, or the old. Pregnant cows aiming to have their babies in the Mara often drop them on the way. They become juicy morsels for the lion, the leopard, and the cheetah.
The biggest hazard is the Mara River, which the gnu have to cross. They bound down the banks, pushed on by eager gnus behind, straight into the territory of waiting crocodiles. Those who survive the lions and crocodiles face the threat of vultures and other carron birds.
And when it is time for the millions to go back in October they mill around the plain in groups waiting for nature's signal to go home -- or is it the "Great Gnu?" In unison the gnu form up and gallop home to the Serengeti.
Do you want a bird's-eye view of one of nature's greatest spectacles? The Kenyans will arrange for one of those little planes specially organized for the tourist.