For many visitors, witnessing the annual “Great Migration” is the main reason to visit Tanzania or Kenya.
But here’s the thing—it’s not a one-time show! The migration is a never-ending, year-round annual wildlife journey split into key phases. From newborn calves to heart-stopping river crossings, each phase of the migration brings its own unique excitement!
Calving season
It kicks off with the calving season on the Serengeti’s southern plains, where wildebeest and other grazers give birth in a dramatic display of new life. From late January to early March, approximately 500,000 wildebeest calves are born in the Serengeti – an explosive birth rate of 8,000 to 10,000 wildebeest calves born daily.
River Crossings
As the herds move northward, they dare perilous river crossings in an iconic scene of survival and endurance, as they battle strong currents and high numbers of crocodiles waiting for an easy meal. They’ll face the Grumeti River in the Western Corridor (typically late May to early June) and the wider and deeper Mara River in the northern Serengeti, at the border with Kenya’s Maasai Mara (generally July to October).
Year-round action
Throughout the year, the Serengeti remains home to plenty of resident game, ensuring the action never truly stops.
The general movements of the herds are often mapped out, but nature doesn’t always follow predictable patterns. Take 2006, for example: the big herds decided to hang out in the central Serengeti in January and February, then unexpectedly shifted south in April and May.
The animals are constantly on the move, sometimes covering up to 40 km in a single night.
And don’t expect one giant parade—it’s more like a series of pop-up gatherings, with many small and large groups, each moving to its own beat.
The movement of the herds in the Serengeti is influenced by a complex interplay of factors that determine when and where the animals travel.
Rainfall plays a crucial role; its timing, duration and intensity significantly affect both grazing conditions and water quality. Many streams and rivers in the region contain high levels of chloride and fluoride, resulting in an unpleasant smell that animals tend to avoid. While heavy rainfall can flush out these salts and restore the water to a drinkable state, light rains do not have the same effect.
Fires – whether controlled burns set by National Parks or uncontrolled fires ignited by poachers – can temporarily drive herds away until new grass emerges, often within a week or two. The ever-present threat of predators keeps the herds on alert, and the absence of fences allows them to roam outside of the ‘borders’ of the parks in search of grazing.
The migration cycle is unpredictable and far from an exact science. Our migration map offers a useful guide to help you navigate this captivating journey year-round.