East African Wildebeest Migration
The East African migration takes place in two main areas – Tanzania’s Serengeti in the south and Kenya’s Maasai Mara in the north.
Each destination is good at completely different times of the year - generally the migration is active in Tanzania’s Serengeti for 9 months; it’s active in Kenya’s Maasai Mara for 3 months during August/September/October.
- The "short" and light rains fall in November and December (sometimes as early as October). This draws the migration rapidly south from Kenya's Maasai Mara down the eastern side of Tanzania's Serengeti into these sweet short-grass plains.
- The wildebeest settle in the southern plains between about January and April - there's lots of food.
- In April and May the "long" or heavy rains set in and the depleted southern plains are less attractive than the long grass plains up in the western corridor and the migration has started moving north (westerly) again.
- Large river crossings on the Grumeti and Mara Rivers occur as the migration heads back into Kenya's Maasai Mara - the season dries out and fresh grazing and water can be found in the far north. The Mara is usually at its best in August, September and October.
The migration itself involves around 1.5 million wildebeest, gazelle and zebra on the move. Resident game (predators and other mammals) are generally fixed to territorial areas and don’t follow the migration much beyond their own ranges; they can be found in their home ranges year round.
Refer to the maps - note the Serengeti Plains are in the south, the western corridor in the west, the Lobo Hills in the north and Seronera in the centre. The Maasai Mara is in the far north of the Serengeti-Mara ecosystem.
The migration is largely driven by the rains, which determine when the animals start moving. A basic outline of how this works is described here, but it is important to remember that rains cannot be timed exactly, and so the migration doesn’t operate on a set schedule! It also doesn’t follow a set route; nor, indeed, do the animals all go the same way. This is part of what makes the site of the migrations so spectacular – hundreds of thousands of animals following different routes to the same destination, spread across the vast plains as far as the eye can see.
Now if only the rains fell on cue!
The migration is a sight to remember, and is something that every traveller to East Africa should plan on seeing.
Despite all the vagaries of weather patterns and apparently random game movements coupled with pressure to find the right spots ... planning a trip to catch the best of the migration is reasonably straight forward......in either Tanzania or Kenya...and at any time of the year
The theory behind how the migration works is simple: seasonal rains and the availabilty of grazing determines the "clockwise" movement of the migration in the larger Serengeti eco-system that includes Tanzania's Serengeti and Kenya's Masai Mara. A few physical barriers like the Simiti and Lobo hills, the Grumeti and Mara rivers hinder and alter this "circular" path.
Well in reality it's not quite that simple!
So here's a more informed explanation on how the migration really works...courtesy of Richard Knocker:
The wildebeest want to be in the short grass plains of the southern Serengeti [in Ndutu/Gol/Southern Loliondo] but the water and grazing cannot support them all year round. This is where they choose to give birth to their young (usually Feb – March), with the rich grass to support them. Within a relatively short space of time, perhaps 4 to 6 weeks, several hundred thousand calves will be born and this is where we see much of the dramatic predator action. The Migration will move off in search of sustenance in response to periods of dry weather, but they will leave this area as late as possible and come back as soon as they can. This means that every year is different and, in fact, every week can be different.
The Migration is also not a continually forward motion. They go forward, back and to the sides, they mill around, they split up, they join forces, they walk in a line, they spread out, they hang around. You can never predict with certainty where they will be; the best you can do is to suggest likely timings, based on past experience - but you can never guarantee the Migration 100%.
So, soon after the short rains start, we would expect them to be in, or close to, the short grass plains area (centred around Naabi/Ndutu/Gol) from December through to April. Depending on local rainfall, they might be anywhere from Moru Kopjes through to the slopes of Ngorongoro.
From May, the rains stop and the herds gradually start moving: generally, as the plains of the south and east dry out, there is a movement to the north and west, where there is more grass and more dependable water.
Not all the wildebeest and zebra will follow the same route: this means that, while part of the migration will head to the western corridor and the Grumeti River before proceeding north, significant numbers may also go up through Loliondo, or via Seronera and Lobo.
In a dry year, the first wildebeest could be near the Mara River (the only decent permanent water in the ecosystem) in early July; in a wet year - mid August. If conditions are very good, i.e. there is plenty of grass and water; the herds will be spread out all the way from Seronera to the Mara River.
- The Migration as a whole need not all pass into Kenya and many stay behind or cross and re-cross the border areas. This carries on through till October/November, when they will start thinking of heading back. Again this will be dependent on the rains.
- The river crossings happen at any time during this time of year, but are elusive, rapid and unforgettable experiences.
- The areas the wildebeest cover are vast, even when crossed in a 4WD car.
- The groups may be spilt over a wide area and finding one on the brink of crossing is not a given.
- The wildebeest are also easily spooked by real or imagined threats. They fear crossing the river, as they have an inkling that something lurks there.
- Patient waiting near a herd by the river may only produce a puff of dust as they turn on their heels and run away. Or maybe the herd is just not ready to cross the river and they are milling around contentedly.
- But if everything is right then, there is utter and extraordinary chaos as the herds struggle to get to the other side of a major river filled with crocodiles.