The southern plains of the Serengeti are very fertile but they need rains to ripen the grass for a massive population of grazers.
The "short" and light rains fall in November and December (sometimes as early as October). This draws the migration rapidly south from Kenya's Masai Mara down the eastern side of Tanzania's Serengeti into these sweet short-grass plains.
The wildebeest and other ungulates settle in the southern plains between about January and April - usually the "easiest" time to see the migration in Tanzania. In April and May the "long" or heavy rains set in. 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 small maps below give a general idea on the movement of the migration, see a more detailed map of the Serengeti ecosystem plus explanations on how the migration really works!
The migration started leaving kenya's Maasai Mara in November. It moves quickly south down the Loliondo boundary. The rains have started and fresh grass covers the Serengeti Plains.
The migration is settled in the short grass lands on the southern plains. Game moves into the Ngorongoro Crater. Zebra are foaling.
Over 2 million wildebeest, zebra, gazelles, eland and predators are in the Serengeti plains. Wildebeest are dropping foals.
The heavy rains are approaching and teh short grass plains are starting to take starin.
The migration starts moving slowly through woodlands towards the western corridor as the long or heavy rains set in. The wild flowers come out in full boom.
The migration follows the Mbalageti river towards the Grumeti Controlled Area where the long grass plains and woodlands provide food.
The rains are ending and the dry season is approaching as the migration crosses teh Grumeti River - the Grumeti crocodiles enjoy their annual feast.
Then migration moves north east through the Grumeti towards the Ikorongo Controlled Area. Some migratory animals move towards the Lobo area.
Most of the migration is concentrated in the Ikorongo area where the Mara is crossed to get into the sweet grasses of the Maasai Mara.
The migration moves into Kenya's Maasai Mara in search of water and fresh grazing.
Then Serengeti is near the end of the dry season, water is available in the Maasai Mara.
The migration starts moving south in anticipation of the new seasons rains which are usually about to start.