Ngorongoro Conservation Area
The Ngorongoro Conservation Area or NCA is a conservation area situated 180 km (112 miles) west of Arusha in the Crater Highlands area of Tanzania. The conservation area is administered by the Ngorongoro Conservation Area Authority, an arm of the Tanzanian government, and its boundaries follow the boundary of the Ngorongoro Division of Ngorongoro District. It covers an area of 8,288 km² (3,200 square miles) - about the size of Crete.
The Ngorongoro Crater is within the area and is the world's largest volcanic caldera. Based on fossil evidence found at the Olduvai Gorge, it is known that various hominid species have occupied the area for 3 million years. Hunter gatherers were replaced by pastorialists a few thousand years ago. The Mbulu came to the area about 2,000 years ago, and were joined by the Datooga around the year 1700. Both groups were driven from the area by the Maasai in the 1800s.
Massive fig trees in the northwest of the Lerai Forest are sacred to the Maasai and Datooga people. Some of them may have been planted on the grave of a Datago leader who died in battle with the Maasai around 1840. No Europeans are known to have set foot in the Crater until 1892, when it was visited by Dr. Oscar Baumann. Two German brothers farmed in the Crater until the outbreak of World War I, after leasing the land from the German colonial administration then in control of East Africa. Dr. Baumann shot three rhinos while camped in the crater, and the German brothers regularly organized shooting parties to entertain their German friends. They also attempted to drive the wildebeest herds out of the crater.
The Ngorongoro area originally was part of the Serengeti National Park when it was created by the British in 1951. Maasai continued to live in the newly created park until 1959, when repeated conflicts with park authorities over land use led the British to evict them to the newly declared Ngorongoro Conservation Area. The Ngorongoro Conservation Area Authority is the governing body regulating use and access to the NCA. The area became a UNESCO World Heritage Site in 1979. The area is part of the Serengeti ecosystem, and to the north-west, it adjoins the Serengeti National Park and is contiguous with the southern Serengeti plains, these plains also extend to the north into unprotected Loliondo division and are kept open to wildlife through trans-human pastoralism practiced by Maasai.
The south and west of the area are volcanic highlands, including the famous Ngorongoro Crater and the lesser known Empakai. The southern and eastern boundaries are approximately defined by the rim of the Great Rift Valley wall, wich also prevents animal migration in these directions. The annual ungulate migration passes through the NCA, with wildebeest and zebra moving south into the area in December and moving north in June. This movement changes seasonally with the rains, but the migration will traverse almost the entire plains in search of food.
The NCA has a healthy resident population of most species of wildlife, in particular the Ndutu Lake area to the west has strong cheetah and lion populations. A population of approximately 25,000 large animals, largely ungulates along with reputedly the highest density of mammalian predators in Africa, lives in the crater. These include the black rhinoceros, whose local population declined from about 108 in 1964-66 to between 11-14 in 1995, and the hippopotamus, which is very uncommon in the area. There also are many other ungulates: the wildebeest (7,000 estimated in 1994), the zebra (4,000), the eland, and Grant's and Thomson's gazelles (3,000). The crater has dense population of lions, leopards, elephants, mountain reedbuck, and buffalo.
The main feature of the NCA is the Ngorongoro Crater, which is the world's largest unbroken, unflooded volcanic caldera. The Crater, which formed when a giant volcano exploded and collapsed on itself some two to three million years ago, is 610 m (2,001 ft) deep and its floor covers 260 km² (102 square miles). Estimates of the height of the original volcano range from fifteen to nineteen thousand feet (4500 to 5800 metres) high. The conservation area also protects Olduvai Gorge, situated in the plains area. It is considered the seat of humanity after the discovery of the earliest known specimens of the human genus, Homo habilis as well as early homonids, Paranthropus boisei. The Olduvai Gorge or Oldupai Gorge is a steep-sided ravine in the Great Rift Valley, which stretches along eastern Africa. Olduvai is in the eastern Serengeti Plains in northern Tanzania and is about thirty miles long. It lies in the rain shadow of the Ngorongoro highlands and is the driest part of the region. The gorge is named after the Maasai word for the wild sisal plant, Sansevieria ehrenbergii, commonly called Oldupaai. It is one of the most important prehistoric sites in the world and research there has been instrumental in furthering understanding of early human evolution. Excavation work there was pioneered by Mary and Louis Leakey in the 1950s and is continued today by their family. Some believe that millions of years ago, the site was that of a large lake, the shores of which were covered with successive deposits of volcanic ash. Around 500,000 years ago seismic activity diverted a nearby stream which began to cut down into the sediments, revealing seven main layers in the walls of the gorge.