Once again this year, one of the most eagerly awaited events for passionate naturalists, animal lovers and photographers from all over the world is approaching.
In Kenya and Tanzania, the time of the great migration is approaching for tens of thousands of wildebeests, often imitated, though not with the same temperament and mass urgency, by other herbivores.
A most exhilarating but also dramatic moment, which is part of the cycle of life and regulates the biological balance of the great mother Africa, is that of the crossing of the Mara river, in the area of the Maasai (called Maasai Mara) practically on the border between the two East African nations united by a single great savannah.
Thousands of wildebeests these days are about to set out to ford the river that divides Tanzania's great Serengeti National Park and flows into the Kenyan reserve.
The transhumance usually begins at the end of May, with the arrival of the great rains that move from west to east. The phenomenon, however, is not simultaneous for all the animals, but is protracted over time, with a migration formed by the combination of many herds of herbivores.
Each herd can number as many as 80,000, but most are smaller. In June, following the tracks of the Serengeti plain, the wildebeests move towards the Grumeti River and the Western Corridor, then splitting into 2 large streams: one crosses the Grumeti River and heads north-east towards the river and the Masai Mara reserve, the other follows the river course and heads north-west towards Lake Victoria.
When the herds arrive at the rivers, one of the most famous and bloody natural spectacles can be witnessed: the passage of the herds at the fords of the Grumeti and Mara rivers infested with crocodiles. Anything can happen, but sometimes you have to wait for hours or days before all hell breaks loose and the hunt is on. Zebras and wildebeests bravely do not give up their migration, but many of them perish. The muddy rivers and strong currents make fording even more treacherous, but instinct gets the better of them and often joint action is what saves most of the beasts. 
On the banks, felines can also be seen, ready to wait for the exhausted and ford-tested animals, and vultures, ready to feed on the carcasses. An epic documentary scenario, which those who love Africa cannot help but dream of experiencing at least once in their lives.

(Photo courtesy of Paolo Torchio)