Every year, one of the most extraordinary spectacles on the planet unfolds across the grasslands of East Africa. Approximately 1.5 million wildebeest, joined by 200,000 zebras and 350,000 Thomson's gazelles, undertake a relentless, circular journey across the Serengeti-Mara ecosystem — driven entirely by instinct, rain, and the endless pursuit of fresh grass. This is the Great Migration, and if you witness it even once, it will remain the defining wildlife experience of your lifetime.
The Great Migration is not a single event but a year-round cycle with distinct phases. The herds never truly stop moving — they follow a roughly circular route spanning over 1,800 kilometres across Tanzania's Serengeti National Park and Kenya's Maasai Mara National Reserve. What makes it the largest overland migration on Earth is the sheer scale: more than two million animals moving as a single, instinct-driven mass.
The primary trigger is rainfall. As the rains move across the ecosystem, fresh grass shoots up in their wake, and the herds follow. Predators — lions, cheetahs, wild dogs, crocodiles — follow the herds. And tourists from around the world follow the predators. Understanding the seasonal calendar is the key to planning your visit.
The southern Serengeti's Ndutu region is the cradle of the migration. This is calving season, and it is breathtaking in its own right. Up to 8,000 wildebeest calves are born every single day during peak calving in February. The calves can stand within minutes of birth and run within hours — they have to, because the short grass plains of Ndutu attract an extraordinary concentration of predators. Cheetahs, lions, hyenas, and jackals stalk the edges of every herd. Watching a cheetah family bring down a young calf at dawn, with Kilimanjaro faintly visible on the horizon, is a scene that defies description. For wildlife photographers, January through March in the southern Serengeti is arguably the best time anywhere in Africa.
As the long rains arrive and the southern grasses dry out, the herds begin their northward push through the central and western Serengeti. This phase is less dramatic visually but marks the buildup to the most famous event of all. The herds consolidate into massive columns, stretching for kilometres across the plains. By June, the lead herds are approaching the Grumeti River in Tanzania's western corridor, where giant Nile crocodiles — some over four metres long — have been waiting motionless for months.
This is the moment that has made the Great Migration world-famous. From July through October, the herds push into Kenya's Maasai Mara and face the Mara River — a brown, crocodile-filled torrent that stands between them and the lush northern grass. The crossings are chaotic, terrifying, and utterly compulsive to watch. A herd may pace the riverbank for hours, then suddenly one brave individual launches in, and thousands follow in a thundering, splashing wave. Crocodiles explode from the water. The banks erode under the weight of hooves. Animals are swept downstream, some scramble out safely, others do not. It is raw nature at its most visceral, and it can happen multiple times a day at different crossing points.
The primary crossing points are at the Mara Triangle (crossing into Kenya) and the return crossings heading back south in October and November. The most reliably productive crossing points include Serena Crossing, Crossing One near Governors' Camp, and the crossings near Rekero Camp.
As the short rains arrive in November, the herds begin filtering back south through the Mara and into the Serengeti, often providing exciting secondary crossings. By December, the circle is complete, and the herds are back in the southern Serengeti, ready to begin calving once more.
Positioning is everything during crossing season. The camps closest to the main crossing points fill up by January for the July-October season. Here are the top properties Savanna Sojourns recommends:
Experienced guides know the signs of an imminent crossing: a herd bunching at the riverbank, animals milling and reversing, the nervous energy of thousands of animals testing the water's edge. Your guide will position the vehicle with patience — sometimes waiting two or three hours. Then, seemingly without warning, it happens.
The sound is the first thing that hits you — a rumble that builds to a roar as hooves pound the bank and then the water. Dust and spray mix in the air. The smell of churned mud and animal is overwhelming. Crocodiles thrash. Wildebeest bellow. The crossing may last five minutes or twenty. Afterward, the survivors stream up the opposite bank and disappear into the grass as if nothing happened. You will sit in silence for a long moment.
"I have guided over 400 Mara River crossings in 22 years. Every single one is different. Every single one leaves me speechless." — James Ole Ntimama, Senior Savanna Sojourns Guide
The Great Migration offers some of the most dramatic wildlife photography opportunities on Earth, but the conditions are challenging. Here is what our photography specialists recommend:
Long-range forecasts from the Kenya Meteorological Department indicate a strong La Niña pattern persisting into mid-2025, which historically correlates with above-average long rains in April and May. This means the southern Serengeti grasses will be exceptionally lush during calving, supporting higher calf survival rates. More importantly, the rivers — especially the Mara — are expected to be running at strong levels through October, which tends to concentrate the crossings at fewer, more accessible points and makes individual crossings more dramatic. The herds in strong-water years do not trickle across in small groups; they mass on the banks and cross in enormous waves.
Additionally, the Kenyan government's continued investment in anti-poaching operations in the Mara ecosystem has led to steadily increasing wildebeest numbers over the past five years. The 2024 aerial census recorded the highest wildebeest population since 2011. More animals means more dramatic crossings, larger herds on the plains, and more predator-prey interactions.
Savanna Sojourns has partnered with three new private conservancies bordering the Maasai Mara for 2025, giving our guests access to areas where no other vehicles are permitted. If you have always dreamed of watching a crossing with a cold sundowner in hand and no other tourist in sight, 2025 is your year.
Our expert guides are ready to craft your perfect African adventure.
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