The Masai Mara National Reserve is a wildlife sanctuary in southwestern Kenya; it serves as the base for the Holekamp Lab's field research. The reserve is named after the Masai people, who call this tropical grassland home.
The country of Kenya is in East Africa. It is bounded on the east by the Indian Ocean, and it is divided roughly in half along its north-south axis by the Great Rift Valley - a long valley made from several geological faults which extend from Syria in the Middle East to Mozambique in southern Africa. The southern edge of the Masai Mara National Reserve is formed by the border with Tanzania, the country immediately south of Kenya.
Immediately over the border from the Masai Mara is the Serengeti National Park. No fences divide these two great reserves, so wildlife can freely travel between them. This provides the setting for the Great Migration each year in which roughly one million wildebeest and ten thousand zebra move large distances in search of seasonal food and water.
Each year in July and August, the wildebeest and zebra move from the Serengeti (a Masai word meaning "endless plains") to the Masai Mara after depleting the Serengeti of its food resources. The animals are drawn to Masai Mara by its rich grasslands and permanent water. After grazing through the summer, the wildebeest and zebras head southward to return to Tanzania in search of more food.
The vast rolling grasslands of the Masai Mara support not only the migratory ungulates, but also large numbers of resident antelope as well. Before and after the Great Migration, hyenas and other predators rely on these resident herbivores, but when the migration arrives, they usually switch quickly to feed on wildebeest and zebra.