This image released by Discovery shows Cheetah cubs from episode two of 'Serengeti,' a six-part series premiering Sunday, August 4. (Richard Jonesl/Discovery via AP)This image released by Discovery shows a Leopard from episode four of 'Serengeti,' a six-part series premiering Sunday, August 4. (Geoff Bell/Discovery via AP)This image released by Discovery shows a Zebra stampede from episode four of 'Serengeti,' a six-part series premiering Sunday, August 4. (Geoff Bell/Discovery via AP)This image released by Discovery shows Wildebeest migrating in a scene from episode three of 'Serengeti,' a six-part series premiering Sunday, August 4. (Geoff Bell/Discovery via AP)This image released by Discovery shows wild dog pups from episode four of 'Serengeti,' a six-part series premiering Sunday, August 4. (Geoff Bell/Discovery via AP)