It is the annual wildebeest migration that plants the Masai Mara National Reserve in the imagination. With a lemming-like instinct, finally gelled into mass movement, the herds gather in their hundreds of thousands on the withering plains of the Serengeti to begin the long, streaming journey northward following the scent of moisture and green grass in the Mara. They arrive in July and August, pouring over the Sand River and into the eastern side of the reserve around Keekorok, gradually munching their way westwards in a milling, unsettled mass and turning south again in October. Never the most graceful of animals, wildebeest play up to their appearance with frolicsome, unpredictable behaviour, bucking like wild horses, springing like jack-in-boxes, or suddenly sprinting off through the herd for no apparent reason.
The Mara River is the biggest obstacle they come up against. Heavy rains falling up on the Mau range where the river rises can produce a sudden brown flood which claims thousands of animals as they try to cross. Like huge sheep (they are, in fact, most closely related to goats), the brainless masses swarm desperately to the banks and plunge in. Many are fatally injured on rocks and fallen branches; others are skewered by flailing legs and horns. With every surge, more bodies bob to the surface and float downstream. Heaps of bloated carcasses line banks, injured and dying animals struggle mournfully in the mud; vultures and marabou storks squat in glazed, postprandial stupor.
The migration’s full, cacophonous impact is awesomely melodramatic – both on the plains where the multitudes graze and cavort, and at the deadly river crossings. This superabundance of meat accounts for the Mara’s big lion population. Through it all, the spotted hyenas scamper and loiter like psychopathic sheep dogs. Half a million wildebeest calves are born in January and February before the migration; two out of three perish without returning to the Serengeti
