Life on the Savannah: Big Cats: The vast east African savannah is the only place in the world where "big cats" -- lions, leopards and cheetahs -- can be seen in a single location. The abundant source of food is the reason why these cats, which reign at the top of the food chain, can survive. The endless grassland gives them life. This is the story of the animals on the savannah, the more than one hundred species of herbivores such as gazelles and buffalos, and the big cats standing at the top of the ecosystem