East African savannas have fascinated generations of explorers, scientists, and the public. Nowhere else is there such a concentration and diversity of large, charismatic animals, and nowhere else is ecology portrayed so dramatically. Spectacular migrations of a million wildebeest tracking the rains dominate the Serengeti-Mara ecosystem of Tanzania and Kenya. Lions and hyenas pursue gazelle, zebra, and buffalo in a conspicuous contest between predator and prey. And giraffe and elephants shape the landscape by browsing and trampling savanna trees. The