The Ruaha River provides the lifeblood of this area of amazing biodiversity, sustaining massive numbers of Nile crocodile, pods of hippo, huge herds of elephant, and an abundance of giraffe, zebra, impala and other herbivores, which in turn support a healthy predator population – prides of lion numbering 20 or more are not uncommon. Over ten percent of the world's lion population lives in the Greater Ruaha ecosystem, which also supports the world's third largest population of wild dog and one of the few sustainable cheetah populations left in East Africa.