Ngorogoro was created when a large volcano exploded and collapsed on itself two to three million years ago.Its floor covers 100 square miles and it is home to some 25.000 animals. Due to the enclosed nature of the Crater it has virtually formed its own ecosystem.
Both the Ngorongoro highlands and the crater offer excellent birding, with over 500 species recorded. Birdlife in the highland forest is rich and interesting. Among the birds to be seen are white-eyed slaty flycatcher and Livingstone turaco. A number of specialized grassland birds are resident in the crater. Most noticeable are ostrich, kori bustard, crowned crane and the secretary bird. Migratory birds are present from November to April.
The NCA became a Man and Biosphere Reserve in 1971 and was declared a World Heritage Site by UNESCO in 1979.