The endless plains of Kenya and Tanzania are the setting for the world’s greatest wildlife spectacle; the Great Wildebeest Migration. From the vast Serengeti plains to the champagne coloured hills of Kenya’s Masai Mara more than 1.4 million wildebeest and 200,000 zebra and gazelle, relentlessly tracked by Africa’s great predators, migrate in a clockwise direction over 2,800 kilometres each year in search of rain ripened grass.

There is no real beginning or end to a wildebeest’s journey. A wildebeest’s life is an endless pilgrimage, a constant search for food and water. The only beginning is at the moment of birth. An estimated 400,000 wildebeest calves are born during a six week period early each year – usually between late January and mid-March.

The Migration pattern is never the same each year. It changes every year, and it all depends on the rainfall. Sometimes the Migration will be off by 50 kms from where the animals are expected to be, and sometimes they will be as much as 200 kms away from there original pattern that has now been studied over many years. Some years it is 2 to 3 weeks early, other years 2 to 3 weeks late. No one can fully predict what may be seen where at any given time, and this is part of the magic and the mystery of the awe-inspiring natural wonder that is The Great Migration. 

The winter rains in Tanzania’s southern Serengeti and Ngorongoro Conservation Area, both UNESCO World Heritage Sites, triggers the growth of lush new grasses that are irresistible to East Africa’s wildebeest, zebra, and gazelle populations. They congregate in the area as a result, alongside elephant and other iconic species, in turn drawing in hungry big cats from far and wide. This is the start of the calving season.

February sees a bounty of newborn wildebeest calves come into the world. Tragically vulnerable to being picked off by predators, up to 90% are born in just three weeks, giving them the best chance of survival through sheer weight of numbers. Somewhere in the region of 8,000 wobbly calves appear each day, which are a delight to watch being born and taking their first steps just a few minutes later.

As February becomes March, local rain showers trigger the wildebeests’ migratory instincts and the huge herds begin to move, for some calves within just a few days of birth. They cross the southern Serengeti in a clockwise direction, cropping the fresh grasses as they go.

Throughout April the migration continues to drift northwards, in expectation of the ‘long rains’ that the building clouds say will break any day and continue on and off until the beginning of June. The huge number of individual animals involved means that its columns stretch from the trimmed vegetation of the southern plains and through the Moru Kopjes towards the Serengeti’s Western Corridor. The coming of the rains does little to affect safari operations, except to limit access to some of the boggiest areas on the plains, with the Seronera area camps keep wildlife lovers close to the action.

By the time May comes around the bulk of the Great Migration herds have reached the Western Corridor, which stretches towards Lake Victoria. It equates to an area just 80 km long bordered to either side by hills. As they reach the banks of the Mbalageti and then the Grumeti Rivers they temporarily pause, waiting for a critical mass to form before taking on the steep banks, strong currents, and lurking crocodiles.

The river crossings are now in full swing, with long columns of wildebeest fighting for the relative safety of the centre. They swim across as quickly as possible, knowing crocodiles lie within striking distance. The adrenaline of the crossing is heightened further by the testosterone drifting through the herd’s males as they battle for the right to mate with the now-receptive females.

The surviving members of the herd now turn back east, and then north, to tackle what is perhaps the most famous singular event in the Great Migration, the crossing of the Mara River. Flowing from Lake Victoria, the river cuts across Tanzania’s northwesternmost corner before crossing the unfenced border into Kenya’s Maasai Mara National Reserve. Now flooded from the rains, viewing this quintessential safari spectacle is similar on either side of the border.

The frenetic crossings of the Mara River continue into August, and while this is undoubtedly one of the best times to visit Kenya for the Great Migration it is also one of the busiest, with nearby lodges fully booked throughout the month.

After all the activity of August’s river crossing, September can seem like something of a lull in proceedings. Some of the immediate tension that built with predators lurking in the river and on its banks now wanes. While still aware of the daily threat they face, the wildebeest, zebra, and gazelle now seem content to feast on the fresh young shoots that brought them here in the first place. As a result, the Mara’s plains are studded with endless slowly shifting bodies and the sound of happy ungulates. However, lions, leopard, and cheetah are never far behind.

The allure of fresh grass, which the great herds pick up from vast distances with their impressive sense of smell, draws them back across the Kenya-Tanzania border from the Maasai Mara into the Serengeti. As the dry season progresses, the rivers lose much of their volume and a lot of their fearsome reputation. These natural bottlenecks still provide perfect viewing opportunities, with the added allure of new born zebra foals joining the journey.

The slow trek back south continues. The animals have a tough task to balance – they need to return to the southern Serengeti for the explosion of new grasses that come with the season’s ‘short rains.’ But get there too early, and they’ll struggle to find enough nourishment for themselves and their calves, which are still less than a year old. It makes November one of the best times to visit Tanzania for the migration.

By December most of the two million animals that make up the Great Migration have made it back to the far south, with the eastern Serengeti and central Seronera region more than suitable bases to enjoy the show. The animals fatten themselves up as much as possible, knowing the magical movement of millions is set to begin again very shortly.