When did the great migration of animals in Kenya begin? When will it end?

There is a period of animal migration, that is, from the beginning of July to the end of September every year. At that time, Kenya Masai Mara National Wildlife Refuge will stage the activity of "Crossing the Mara River". In the narrow estuary of the Mara River, millions of animals push each other and trample on each other. Crossing the raging rapids of the Mara River and the obstruction of crocodiles is the most difficult and spectacular scene. This is called "crossing the Mara River" or "crossing heaven". August is a good time, good luck!