Serengeti direction through the Serengeti National Park and north towards the Masai Mara reserve in Kenya. This migration is a natural phenomenon determined by the availability of grazing. The initial phase lasts from approximately January to March, when the calving season begins – a time when there is plenty of rain-ripened grass available for the 260,000 zebra that precede 1.7 million wildebeest and the following hundreds of thousands of other plains game, including around 470,000 gazelles. During February, the wildebeest spend their time on the short grass plains of the southeastern part of the ecosystem, grazing and giving birth to approximately
Serengeti low of in the lee of the Ngorongoro highlands to a high of on the shores of Lake Victoria. The highlands, which are considerably cooler than the plains and are covered by montane forest, mark the eastern border of the basin in which the Serengeti lies. The Serengeti plain is punctuated by granite and gneiss outcroppings known as kopjes. These outcroppings are the result of volcanic activity. Kopjes provide a microhabitat for non-plains wildlife. One kopje likely to be seen by visitors to the Serengeti is the Simba Kopje (Lion Kopje). The area is also home to the Ngorongoro Conservation