The wildebeest migration was named the ‘eighth Wonder of the World’. This is the largest assembly of animals in the planet Earth. The principle players are the wildebeest, whose numbers appear to have settled at just under 1.7 million, with supporting roles from some 400,000 Thomson’s gazelle, 300,000 zebra and 13,000 elands. The migration is a cycle that takes place in both the greater Masai Mara and Serengeti Ecosystems. The wildebeests’ journey is dictated primarily by their response to the weather; they follow the rains and the growth of new grass.
This is the migration cycle of the East African wildebeests.
During this period of the year the rains set in and the animals move north-west towards the woodlands of the hilly country west of Seronera towards Lake Victoria. This is the time vicious fighting between dominant or territorial males takes place in competition for female partners. Over 500,000 cows are impregnated in less than a month. They remain in-calf for the next eight and a half months.
This is the most fascinating moment being at the Mara Ecosystem. The wildebeests continue following the rains as it heads northwards into Kenya. The Mara plains are also filled with plenty of grass prior to their arrival. Before they reach the Mara they go past several obstacles; Rivers Gurumeti and Mbalangeti in the Serengeti and River Mara in Kenya. For most of the year these rivers are relatively placid, but they can become violent torrents in response to rainfall in their catchments areas, and then they present major obstacles to the progress of the wildebeest. During the crossing thousands die due to stampede and are also preyed on by the hungry crocodiles in the rivers.
During this period the other predators like the lions, leopards, cheetahs and other scavengers have plenty to feed on. The predators are unable to follow the moving herds very far, for many are territorial and can neither abandon their territories nor invade those of others.
Having exhausted the Mara plains grass by late October, the wildebeest start heading south again. The herds trek down through the eastern woodlands of the Serengeti. At this time the first of the short rains start falling on the Serengeti’s short-grass plains, filling seasonal waterholes and bringing new flushes of growth. These animals are in constant mode of migration. They trek again throughout the Serengeti Ecosystem which comprises of Ngorongoro Conservation Area in the south, the Serengeti National Park and the adjacent Maswa Game Reserve.
Calving takes place during this time of the year. Some 300,000 to 400,000 calves are born within two to three weeks. The birthing occurs on the short-grass plains that are at the southernmost extent of the wildebeests’ range, spread over the lower northern slopes of the Ngorongoro Crater highlands and are scattered around Olduvai Gorge. The annual period of birthing provides a feast for predators.
Towards the end of the short dry season, around March, the short-grass plains of the southernmost Serengeti begin to dry out and the wildebeest begin or continue their journey, heading towards the western woodlands. To the west there is a trio of small lakes namely; Ndutu, Masek and Lagarja.
Their endless journey continues in a similar cycle though the timing might slightly differ.