Between January and March, half a million wildebeest calves are born in the Serengeti south.
Seasons of new life and action are many Serengeti guides' favourites. Africa's biggest wildlife event is covered here.
The wildebeest herd's 800-kilometer journey is the world's greatest mammal migration.
The movement occurs during wet season greening of nutritious grasses on short-grass plains.
The herd and gazelles and zebras go north to the Masai Mara in Kenya in May to eat the high grass.
Crossing rivers means facing roughly 3,000 crocodiles eager to kill.
The migration returns to the Serengeti with the late October brief rains.