The Great Migration Explained
Everything you need to know about the 1.5 million wildebeest migration — its route, timing, river crossings, and how to witness it.
The Great Migration is the largest land mammal movement on Earth. Every year, roughly 1.5 million wildebeest, 250,000 zebras, and hundreds of thousands of gazelles travel in a continuous loop across the Serengeti-Mara ecosystem — driven entirely by the search for fresh grass and water.
It’s not a single event, and it’s not a single river crossing. It’s a year-round cycle, and understanding how it moves is the key to planning the right safari at the right time.
The Short Answer
If you want to see the migration’s dramatic river crossings: go to the northern Serengeti between July and September.
If you want to see calving season and intense predator activity: go to the southern Serengeti and Ndutu between January and February.
If you want the migration moving through the central and western Serengeti: go in May and June.
The herds are always somewhere — the question is which part of the cycle you want to witness.
What Exactly Is the Great Migration?
The Great Migration is the annual, circular movement of enormous herds of wildebeest, accompanied by zebras and gazelles, across the Serengeti ecosystem in Tanzania and the Maasai Mara in Kenya.
The animals are not migrating to a destination — they are following the rains and the fresh grass that grows in their wake. This constant search for grazing drives the entire cycle, and it repeats year after year with remarkable consistency.
Alongside the herds come the predators: lions, cheetahs, leopards, hyenas, and wild dogs. The migration is not just a spectacle of herbivores — it’s the engine that drives the entire Serengeti food chain.
The Migration Cycle: Month by Month
The migration follows a roughly clockwise route through the Serengeti-Mara ecosystem. Here’s how it unfolds across the year.
December – March
Calving SeasonThe herds gather on the short-grass plains of the southern Serengeti and the Ndutu area. This is calving season — over 500,000 wildebeest calves are born within a few weeks, usually in February.
The sheer concentration of newborn prey draws predators from across the ecosystem. Cheetah, lion, and hyena sightings are exceptional during this window. It’s one of the most dramatic times to be on the plains.
Why Go
- Peak calving and predator action
- Excellent cheetah viewing
- Green, photogenic landscapes
Considerations
- High-season pricing
- Busy camps in Ndutu
- Book well in advance
April – May
Northward MovementAs the rains end and the southern plains dry out, the herds begin moving north and west toward the central and western Serengeti. This is the long-rains period, so conditions are green and wet.
Wildlife is more dispersed during this phase, and the migration can be harder to track. But crowds are minimal, prices are low, and the Serengeti is at its most lush and quiet.
Why Go
- Low crowds and prices
- Green, dramatic scenery
- Excellent birding
Considerations
- Heavy rain and muddy roads
- Migration harder to locate
- Some camps closed
June
Grumeti & Western CorridorBy June, the herds have moved into the western Serengeti and the Grumeti River area. This is where the first major river crossing of the year takes place — the Grumeti crossings.
The Grumeti is smaller and less dramatic than the Mara River, but it’s still a genuine river crossing, complete with crocodiles. Conditions are dry, game viewing is excellent, and crowds are moderate.
Why Go
- Grumeti River crossings
- Excellent game viewing
- Moderate crowds
Considerations
- Prices rising
- Crossings less predictable than Mara
- Cooler mornings
July – September
Mara River CrossingsThis is the phase most people picture when they think of the Great Migration. The herds move into the northern Serengeti and cross the Mara River into Kenya’s Maasai Mara — and then back again.
The Mara River crossings are the migration’s most iconic and most unpredictable moments. Thousands of wildebeest plunge into crocodile-infested water in a chaotic, dust-choked surge. Crossings can happen at any time — or not at all on a given day.
Why Go
- Iconic Mara River crossings
- Best game viewing of the year
- Excellent predator sightings
Considerations
- Very crowded
- Peak pricing
- Crossings are unpredictable
- Book 6–9 months ahead
October – November
Return SouthAs the dry season ends, the herds begin their southward return through the eastern and central Serengeti. The migration starts to spread out again, following the first short rains.
October still offers excellent game viewing with moderate crowds. By November, the short rains have arrived, the parks are green and quiet, and the herds are moving steadily back toward the southern plains.
Why Go
- Excellent viewing in October
- Fewer crowds
- Better pricing
- Herds on the move
Considerations
- River crossings ending
- Short rains in November
- Herds more dispersed
The Route at a Glance
| Months | Location | Key Event | Highlight |
|---|---|---|---|
| Dec – Mar | Southern Serengeti / Ndutu | Calving season | Predator action |
| Apr – May | Central / Western Serengeti | Northward movement | Green season |
| June | Western Serengeti / Grumeti | Grumeti crossings | First crossings |
| Jul – Sep | Northern Serengeti / Mara | Mara River crossings | Peak drama |
| Oct – Nov | Central / Southern Serengeti | Southward return | Quieter viewing |
The River Crossings
The river crossings are the migration’s most famous moments — and the most misunderstood. They are not scheduled events. They happen when the herds decide to move, and no one can predict exactly when or where.
The Grumeti River (June)
The Grumeti crossings take place in the western Serengeti in June. The river is smaller than the Mara, but it still holds large crocodiles, and the crossings can be dramatic. Because fewer travelers target the Grumeti, the experience is often quieter and less crowded.
The Mara River (July – September)
The Mara River crossings are the migration’s headline act. The river runs along the border between the northern Serengeti and Kenya’s Maasai Mara, and the herds cross it in both directions as they follow the grass.
Crossings can involve thousands of animals at once, plunging into water thick with crocodiles. They can also fail to happen for days. This unpredictability is part of the experience — but it means you should plan to spend several days in the area if river crossings are your priority.
Planning Around the Migration
For River Crossings
- July – September
- Northern Serengeti (Kogatende)
- Spend 3–4 nights minimum
For Calving & Predators
- January – February
- Ndutu & Southern Serengeti
- Book 6–9 months ahead
For Value & Solitude
- April – May
- November
- Lower prices, fewer crowds
For Balanced Viewing
- June
- October
- Good wildlife, moderate crowds
Migration Timing at a Glance
| Month | Location | Activity | Crowds | Rating |
|---|---|---|---|---|
| January | Southern Serengeti | Calving begins | High | Excellent |
| February | Ndutu / South | Peak calving | High | Excellent |
| March | Southern / Central | Herds dispersing | Low | Good Value |
| April | Central / Western | Northward movement | Very Low | Good Value |
| May | Central / Western | Herds massing | Low | Good Value |
| June | Western / Grumeti | Grumeti crossings | Moderate | Excellent |
| July | Northern Serengeti | Mara crossings begin | Very High | Excellent |
| August | Northern Serengeti / Mara | Peak crossings | Very High | Excellent |
| September | Northern Serengeti / Mara | Crossings continue | High | Excellent |
| October | Central Serengeti | Southward return | Moderate | Excellent |
| November | Central / Southern | Moving south | Low | Good |
| December | Southern Serengeti | Herds gathering | High | Excellent |
Timing varies year to year depending on rainfall. Use this as a guide, not a guarantee.
Frequently Asked Questions
What exactly is the Great Migration?
It’s the annual circular movement of roughly 1.5 million wildebeest, 250,000 zebras, and hundreds of thousands of gazelles across the Serengeti-Mara ecosystem, driven by the search for fresh grass and water.
When is the best time to see the migration?
It depends on what you want. For river crossings, July–September in the northern Serengeti. For calving and predator action, January–February in the southern Serengeti and Ndutu.
Are the river crossings guaranteed?
No. Crossings are unpredictable and depend on the herds’ movement. To maximize your chances, stay 3–4 nights in the northern Serengeti during peak season and work with guides who track the herds daily.
Where does the migration actually take place?
It moves through the Serengeti ecosystem in Tanzania and the Maasai Mara in Kenya. The route loops through the southern, central, western, and northern Serengeti before crossing into Kenya and back.
Is the migration the same every year?
Roughly, yes — the cycle repeats annually. But exact timing and locations shift depending on rainfall. Some years the herds move early; some years they linger. Flexibility in your itinerary helps.
Do I need a special safari to see the migration?
You need an itinerary that positions you in the right part of the Serengeti at the right time. A knowledgeable operator will build your route around the migration’s expected location during your travel dates.
How far in advance should I book?
For peak migration season (July–September and January–February), book 6–9 months in advance. Lodges in the northern Serengeti and Ndutu fill up especially fast.
Continue Planning
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Essential items including neutral-colored clothing, layers, binoculars, cameras, and luggage weight limits.
Read GuideReady to Witness the Migration?
Let our safari specialists position you in the right place at the right time. Contact us to build your migration-focused itinerary today.
