The Great Migration refers to the annual movement of millions of wildebeest, accompanied by zebras, gazelles, and other animals, across the Serengeti ecosystem in Tanzania and Kenya. This remarkable natural spectacle is driven by the search for food and water, and it involves perilous river crossings and encounters with predators along the way.

The migration typically begins with the onset of the short rains in November and December, as the herds move to the southern Serengeti and Ndutu area for calving. This period is marked by the birth of over half a million calves, making it a prime time for predators to hunt.

As the plains dry up, usually around April, the wildebeest herds begin to migrate northwest toward central Serengeti. From May to June, they head further west to the Grumeti River, where they face the challenge of crossing crocodile-infested waters.

By late July and August, the migration progresses northward to the Mara River, where they again encounter treacherous crossings. Many animals are lost to predators, drowning, or stampedes during these crossings.

In October, the herds move into the Masai Mara Reserve in Kenya, before starting their journey southward again in November, following the cycle of rainfall and fresh grazing grounds.

The Great Migration is a testament to the resilience and adaptability of these animals, as well as the intricate ecological balance of the Serengeti ecosystem.