[Extract] The Serengeti ecosystem is often taken to be the 25000 km2 animal migration area (Figure 1a). This includes the 14,763 km2 Serengeti National Park (SNP), the Masai Mara Reserve in Kenya, and a number of game controlled areas that form a buffer zones, principally the Maswa, Ngorongoro, Loliondo, Ikorongo, Grumeti, and the Speke Gulf Game Controlled Area (SGGCA) that, although tiny (95 km2), is potentially important because, if human encroachment was removed, it would provide access for wildlife to the permanent waters of Lake Victoria (Figure I b). However this definition of the ecosystem ignores the hydrology. The Serengeti ecosystem has only one perennial river, the Mara River. The Mara River, together with a few scattered springs in the northern region of the SNP, is the only source of water for migrating wildlife in the dry season in a drought year. Thus the source of Mara River water in the dry season, namely the Mau forest in Kenya's highlands, is also part of the Serengeti ecosystem even if the migrating animals do not migrate to that area (Gereta et al., 2002 and 2009)
