May-July
This is the period that the wildebeest, after having feasted on the short green grasses of the southeastern Serengeti and after having giving birth to their offspring, start getting ready for their 800 kilometer long trek. The actual starting date may be anytime between late April and early June. This is the time to you may have the privilege to see one of the greatest natural phenomena in the world: more than a million marching animals in a column up to 40 kilometers long. During the migration, the herd will move towards the Western Corridor, where they will face the first major obstacle: crossing the Grumeti River. Many animals don’t survive the crossing as they are being awaited by the area’s population of oversized crocodiles ready to feast. The herd may congregate on the southern bank of the river and stay there for up to two weeks before crossing the river.