The annual migration of two million grazing animals is an annual event in Tanzania. It is led by the need of the animals, wildebeest, zebras, Thompson’s & Grant’s gazelle to find fresh grazing. It is dictated by local rainfall patterns, and whilst there can be variation from one year to the next, it does follow a reasonably predictable annual cycle. Defying superlatives, it has been classed as one of The Seven Wonders of Africa.
The movement of the herds within the Serengeti is constant, but the Great Migration usually refers to the time when the herds start to congregate in the southern plains for the 800km trip to the north, around about the end of April. The actual moving columns of animals might start at any time from late April to early June, with herds of more than a million migrating animals moving steadily in a column up to 40 km long. The Wildebeest form the middle bulk of the column, with their “outriders” the plains zebras acting as their eyes and ears on the edges of the column. The greatest challenge for the columns is when they cross the Grumeti River from June into early July. Many animals die in the crossing, many of them taken by the prolific population of crocodiles, which lurk to pick off the weakest of both the Wildebeest and the zebras. The first to cross are at the greatest risk, and it almost seems as if the herds hesitate before the final plunge. It can take up to two weeks from the time the first animals cross for the crossing to begin, by which time the Western Corridor has thousands upon thousands of animals amassing within it. After crossing the column disperses again with half of them crossing the Mara River into Kenya’s Maasai Mara Game Reserve and the remainder spreading out through the northern and western Serengeti in the Lobo area. By late October, the animals are moving south again towards the Seronera plains to arrive by late November or early December before their calving in January. Thus you can choose your safari to fit in to the migration cycle outlined above.
If you wish to book in late April, May, June, or July, there is a good chance to see the great moving herds. However it cannot be predicted to the day or even the week, when the spectacular Grumeti River crossing will take place. The Serengeti at all times offers game viewing equal, if not better, than any other game reserve in the whole continent.