The Migration movements are dictated by the weather and as such can be subject to unforeseen changes. However it is possible to predict with reasonable accuracy where the vast herds can be located at a given time. It is not an exact science and 2 million animals can disappear overnight The following Calendar gives an idea of normal movements throughout the year.
January – April
The herds of wildebeest and Zebra spend these months on the short grass plains and the surrounding woodlands at Ndutu, Kusini, Maswa.
This is the longest the herds stay in one area, it is the place of mass synchronised births , giving the new generation a good start in life, growing strong on the mineral rich grass. Predators converge on the area to feast on the glut of babies. This is probably the easiest time to predict their location and see the migration in staggering numbers in one place. A breathtaking site.
May – July
When the long rains stop the plains very quickly dry up and any grass loses it’s nutritional value. Without a permanent water supply the vast herds are compelled to move in search of both grazing and water. The Migration begins. The wildebeest, Zebra and Thompson’s Gazelle steadily move north and west, passing through the central area of Seronera and heading for the western corridor. Here they meet the Grumeti river, a river which offers both life and death. It is home to some of the largest Nile crocodiles in Africa, their huge size a consequence of the passing migration. The herds are forced to drink here and ultimately cross the river heading north.
August – October
The Serengeti is now in the grip of the dry season, but farther north in the Maasai Mara in Kenya the short rains (intermittent small showers) have begun. The wildebeests ability to smell rain far away keeps them moving north to their next obstacle, the Mara river. Crossing this river is unavoidable. Again it is home to large crocodiles and the added danger of fast currents. The herds congregate at the waters edge in vast numbers, hesitant to take the plunge, until sheer pressure of numbers forces them into the water. Thousands lose their life here at these chaotic crossing, sometimes being trampled by their own kind, the weak or injured quickly picked off by waiting predators.
The herds now spend time grazing in the Massai Mara region but before long the short rains stop there and begin south in the Serengeti. The return begins.
November – December
On the return south having once again navigated the Mara river, the herds slightly change their behaviour and split into smaller units, some heading straight south others heading south east. Often the Zebra form an advance party, reaching central Serengeti first. Now their movements are a little less predictable as they move around following the showers, sometimes retracing their steps, But their ultimate destination is the short grass plains from whence they started.
Estimates vary as to the distance travelled during the annual migration, but it is something in excess of 1000 kilometres. It is an epic journey undertaken year after year. The huge losses sustained due to predation, disease or injury has little effect on the overall populations. The Migration is a natural spectacle unrivalled anywhere on Earth.
The seasons are divided into wet and dry.
The dry season is characterised by hot days and cold nights and no rain.
Vegetation is sparse and the landscape particularly the open plains are unforgiving. The dry season can last from May to October.
The wet season begins with the short rains usually around late September / October but are frequently later. They consist of small local showers but with dry periods between. The short rains can continue for weeks or months until the long rains begin around March when heavy rain continues for a couple of months.