Since scientist began monitoring wildebeest migration patterns three decades ago, they have observed a shift in patterns in the three regions the wildebeest occupy during the migration. The changes are due to the increase in the wildebeest population.
Once [G 40 / rinderpest] was eradicated from the region in the early sixties, the wildebeest population began to rapidly expand. From 1961 to 1969 their numbers increased from 260,000 to over a half a million forcing them to extend their migration further north into the Masai Mara Game Reserve. Today, during the dry season, wildebeest occupy virtually all of the reserve and part of the [G 29 / Masai's] pastures north of the reserve.
On the plains, the herds have shifted from the longer grass in the northeast portion of the plains, primarily occupied by the zebra, to the central and southwestern plains.
In the Western Corridor, the herds have extended further west, utilizing more of the Ndabaka Plains and Grumeti Controlled Area. They are also grazing further out of the Serengeti into the northwest in the Ikorongo Game Control Area and beyond. The poaching of wildebeest and non-migratory animals is the greatest in the west and northwest regions.
