Overview:Two East African rivers stand in the way of a massive migration. Over a million wildebeest and thousands of zebras will be forced to cross the Grumeti and Mara Rivers in order to complete their epic annual journey, and every crocodile knows it. Discover the very different hunting strategies crocs must use to attack their prey, based on the demands of the ever-changing waterscapes they live in. As trenches shift and levels fluctuate, see how these fierce reptiles adapt to the rivers' wild tempers to become ultimate predators