How the migration works
So what is the best time and where is the best place to catch this spectacle?
Disregard any pretty map you may have been shown that has a nice flow of animals going round in an annual circle.
The Migration does not work like this. It is driven entirely by standing water and grazing, and created by local weather conditions.
Here're some of Richard Knocker's comments on the best time and place to catch the migration.
Richard Knocker was born and brought up in Kenya and after having managed camps in Kenya's Maasai Mara and Tanzania's Tarangire and Serengeti. He's been intimately involved with pioneering conservation efforts in Tanzania and recently described as "Tanzania’s Guide Supremo, teller of really bad puns and owner of three unbelievably unruly but delightful dogs!!"
The wildebeest want to be in the short grass plains of the southern Serengeti [in Ndutu/Gol/Southern Loliondo] but the water and grazing cannot support them all year round. This is where they choose to give birth to their young (usually Feb – March), with the rich grass to support them. Within a relatively short space of time, perhaps 4 to 6 weeks, several hundred thousand calves will be born and this is where we see much of the dramatic predator action. The Migration will move off in search of sustenance in response to periods of dry weather, but they will leave this area as late as possible and come back as soon as they can. This means that every year is different and, in fact, every week can be different.
The Migration is also not a continually forward motion. They go forward, back and to the sides, they mill around, they split up, they join forces, they walk in a line, they spread out, they hang around. You can never predict with certainty where they will be; the best you can do is to suggest likely timings, based on past experience - but you can never guarantee the Migration a hundred percent.
So, soon after the short rains start, we would expect them to be in, or close to, the short grass plains area (centred around Naabi/Ndutu/Gol) from December through to April. Depending on local rainfall, they might be anywhere from Moru Kopjes through to the slopes of Ngorongoro.
From May, the rains stop and the herds gradually start moving: generally, as the plains of the south and east dry out, there is a movement to the north and west, where there is more grass and more dependable water.
Not all the wildebeest and zebra will follow the same route: this means that, while part of the migration will head to the western corridor and the Grumeti River before proceeding north, significant numbers may also go up through Loliondo, or via Seronera and Lobo.
In a dry year, the first wildebeest could be near the Mara River (the only decent permanent water in the ecosystem) in early July; in a wet year - mid August. If conditions are very good, i.e. there is plenty of grass and water; the herds will be spread out all the way from Seronera to the Mara River.
The Migration as a whole need not all pass into Kenya and many stay behind or cross and re-cross the border areas. This carries on through till October/November, when they will start thinking of heading back. Again this will be dependent on the rains.
The river crossings happen at any time during this time of year, but are elusive, rapid and unforgettable experiences.
The areas the wildebeest cover are vast, even when crossed in a 4WD car.
The groups may be spilt over a wide area and finding one on the brink of crossing is not a given.
The wildebeest are also easily spooked by real or imagined threats. They fear crossing the river, as they have an inkling that something lurks there.
Patient waiting near a herd by the river may only produce a puff of dust as they turn on their heels and run away. Or maybe the herd is just not ready to cross the river and they are milling around contentedly.
But if everything is right then, there is utter and extraordinary chaos as the herds struggle to get to the other side of a major river filled with crocodiles.
Click here for more about the East African wildebeest migration