Five facts about the wildebeest migration

1. The great wildebeest migration is an annual clockwise movement of wildebeest around the Serengeti in Tanzania and the Masai Mara in Kenya. Each year, around 1.5 million wildebeest, accompanied by hundreds of thousands of zebra and gazelle, travel in unison on the journey, which can exceed a thousand miles, driven by the search for fresh grasses and drinking water brought by variations in rainfall around East Africa.

2. The wildebeest stop in the Serengeti for their calving season during February and March. Each year, around 400,000 wildebeest are born in a remarkably condensed time-frame. The calves are capable of standing and running with their mothers within minutes of entering the world.

The masses of wildebeest on the move

3. Wildebeest are one of the few types of antelope to have increased their number and range in East Africa during recent years. In fact, their population has grown six-fold from a quarter of a million in the 1960s to 1.5 million today – disease had diminished the number of wildebeest in the late nineteenth century but an inoculation programme had allowed the population to skyrocket in more recent years. This population increase revived the great migration to the form it currently takes, as competition for food and water intensified.

4. The migrating herd of wildebeest is understandably a huge attraction for predators. Their progress is watched closely by lions, cheetahs, leopards, hyenas and crocodiles – with vultures awaiting any leftovers of an attack. The considerable strength of wildebeest, combined with ‘swarm intelligence’, makes captures surprisingly difficult for attackers, and protects the young and weak. Even so, around 250,000 wildebeest are estimated to meet their end during each annual cycle.

5. The most formidable challenges for the animals during the migration come when they are forced to cross rivers, especially the Grumeti in Tanzania and the Mara River in Kenya. Crocodiles await their chance to strike, and the tired wildebeest wrestle against the current. As the wildebeest concentrate in bottlenecks at crossing points, these attempts to get across the rivers are a dramatic highlight for anyone visiting the region at the crucial time.