Driven by localized rainfall patterns and phosphorus content in fresh grass shoots, over 1.5 million wildebeest, 200,000 zebras, and 350,000 gazelles move in an endless 800-kilometer loop between Tanzania and Kenya.
Month-by-Month Migration Cycle
January – March: Southern Ndutu Calving Season
Herds settle in the nutrient-rich volcanic soils of southern Serengeti & Ndutu. Hundreds of thousands of calves are born, attracting major predator activity.
April – June: Central Serengeti & Grumeti Trek
As rains diminish, herds form massive long columns moving northwest toward the Grumeti River corridor.
July – October: Northern Mara River Crossings
Peak river crossing season. Herds brave steep banks and Nile crocodiles along the Mara River into Kenya's Maasai Mara Reserve.
November – December: Return South
Short rains signal the return trek southward through eastern Serengeti to start the cycle anew.