Over a million wildebeests and zebras spend the first months of the year in the great plains of the Serengeti, feeding off the short grass and preparing for migration. The majority of wildebeest calves are born here in February, with around half a million new calves in the Serengeti that month. When pastures begin depleting in the Southern plains that include the Ngorongoro crater conservancy & southern Serengeti national park, the herds begin moving west in search for new pastures. The herds move protecting their vulnerable calves from predators from like lions, cheetahs, leopards, hyenas and wild dogs that lay in waiting for prey. When short dry season sets in usually at the end of March, the short-grass plains of the southern Serengeti begin to dry out and the wildebeests and zebras start to head towards the western woodlands.