This annual rotation of beasts, is a cycle that is influenced by rain, fresh grass shoots, mating and birthing. The main drawcard of this natural spectacle is watching the wildebeest mingle by a river, waiting for the right moment to cross. And once one goes, often the herd will follow as they take their lives in their hands and run the gauntlet against fast flowing currents, stampeding beasts, patient crocodiles, and a line-up of hungry carnivores on the bank beyond.

The annual wildebeest migration varies slightly in timing each year. Generally speaking, the wildebeest migrate (along with a number of zebra, gazelle and other animals) to the Masai Mara in Kenya at the end of June/beginning of July, and then return to the Serengeti in October.
The annual cycle roughly starts when the calves are born on the southern-most plains of the Serengeti ecosystem in January-February. Around March, the short-grass plains begin to dry out and the wildebeest continue their journey, heading towards the western woodlands.
As the rains set in, the herds head north-west, (west of Seronera) towards Lake Victoria. This is the time of the annual rut, with half a million cows mated in less than a month as the herds consolidate in the woodlands and on the plains of the Serengeti's western corridor.

From the western Serengeti the herds head north, following the rains and new grass into Kenya and the Maasai Mara Game Reserve. Their path is cut several times by rivers both in the Serengeti and the Masai Mara and present quite an obstacle for the migrating beasts. Wildebeest can arrive at the Mara River in their tens of thousands, which is often swollen from the rains, and gather waiting to cross. For days their numbers can be building up and anticipation grows but many times, for no apparent reason, they turn and wander away from the water's edge. Eventually the wildebeest will choose a crossing point, something that can vary from year to year and cannot be predicted with any accuracy. Once on the savannah of the Maasai Mara, the wildebeest spend several months feeding and fattening (as most are pregnant), taking advantage of the green pastures and isolated rainstorms. By late October, the first of the short rains are falling on the Serengeti's southern plains, and the wildebeest start heading south again.

In reality, there is no such single entity as 'the migration'. The wildebeest are the migration – with no start or finish to their endless ritual of mating, and searching for food and water. There is also little predictability about the migration, and questions as to which is the best month to view it are likely to get different answers from different people. It is a dynamic process which defies prediction: no two years are ever quite the same.

So the important thing to remember is that 'the migration' is actually the two million plus animals who roam following the new pastures, not the 'river crossings'. If you particularly want to try to see a river crossing, then you would need to book a safari for around a week in the Masai Mara alone, and be prepared to spend a lot of time sitting waiting at the rivers. The spectacle of such a large volume of beasts and carnivores in one place is often spectacle enough. The movement is regulated by habit, but influenced mostly by the rains and new grass, which makes no two years the same.

There are also a number of wildebeest who do not follow the main migration pattern, and are resident to one area. There are others who have a 'mini migration' path, for example the Loita Plains wildebeest.

THE MIGRATION CYCLE

Remember: The movement is regulated by habit, but influenced mostly by the rains and new grass, which makes no two years the same.