he wildebeest migration in East Africa is a continuous and cyclical event that doesn't have a fixed duration. Instead, it's a year-round process that follows a pattern determined by the changing seasons, the availability of food and water, and the need for survival and reproduction. Here's an overview of the different phases of the migration:

Calving Season (Late January to February): The migration typically begins in the southern Serengeti in Tanzania, where wildebeest herds gather to give birth to their calves. This phase coincides with the start of the short rains and the availability of fresh grass for the young calves.

Dry Season (June to September): As the dry season progresses, the wildebeest herds begin their northward migration, following the rains and the growth of new grass. During this time, they move through the central and northern Serengeti.

River Crossings (July to October): One of the most dramatic phases of the migration is the river crossings, particularly at the Mara River in Kenya. As the herds move north, they encounter rivers that must be crossed to reach better grazing areas.

Return South (November): As the dry season ends and the grasses in the northern areas become depleted, the wildebeest herds start their journey back to the southern Serengeti, often arriving in November. This return migration ensures that they have access to fresh grass for the calving season the following year.

Calving Season Again (Late January to February): The migration cycle begins anew with the calving season in the southern Serengeti.

The entire migration cycle lasts throughout the year, and it doesn't have a fixed endpoint. It is a continuous movement of the herds in response to changing environmental conditions. Travelers who want to witness specific phases of the migration should plan their trips accordingly to coincide with the relevant times of the year. The wildebeest migration is a dynamic and ever-changing natural spectacle that offers different experiences at different times.