The Ngorongoro Conservation Area is a protected region and a UNESCO World Heritage Site in Tanzania. It is located in the Ngorongoro District, 180 kilometers west of Arusha City in the Arusha Region, within the Crater Highlands of northeastern Tanzania. The area is named after Ngorongoro Crater, a large volcanic caldera found there. The Ngorongoro Conservation Area Authority (NCAA), which manages the area, is part of the Tanzanian government. The boundaries of the conservation area match the borders of the Ngorongoro District in the Arusha Region. The western part of the area borders Serengeti National Park. Together with Serengeti National Park and Kenya’s Maasai Mara game reserve, the region is home to the Great Migration, an annual movement of millions of wildebeest, zebras, gazelles, and other animals. The NCA also includes Olduvai Gorge, one of the most important sites for studying early humans.

In 2023, the Ngorongoro Conservation Area received 752,232 visitors, making it one of Tanzania’s most popular tourist attractions.

The 2009 Ngorongoro Wildlife Conservation Act introduced new rules to limit human settlement and farming for basic needs in the Crater. This led to the relocation of Maasai pastoralists, many of whom had been moved to Ngorongoro from their original lands to the north when the British colonial government created Serengeti National Park in 1959.

History

The name of the crater comes from the sound of a cowbell, which the Maasai people called "ngoro ngoro." Fossils found at Olduvai Gorge, known as OH 7, show that many early human ancestors lived in the area for at least 1.75 million years.

Hunter-gatherers were replaced by pastoralists, people who raised animals, thousands of years ago. The Iraqw people arrived about 2,000 years ago, and the Datooga joined them around 1700. Both groups were later forced to leave the area by the Maasai in the 1800s.

No Europeans visited the Ngorongoro Crater until 1892, when a man named Oscar Baumann arrived. Two German brothers, Adolph and Friedrich Siedentopf, farmed in the crater from the late 1800s until World War I began. They leased the land from the German East Africa administration and held hunting events for their friends. They also tried to move wildebeest herds out of the crater.

Germans first created game reserves where hunting was allowed. After World War I, when Britain controlled the area (then called Tanganyika), laws were passed in 1921 to protect wildlife and limit hunting. By 1930, the Ngorongoro Crater was included in these protections. A law in 1923 gave the British governor the power to decide land rights for indigenous people, though these rights were still held by local communities until the 1950s. Conflicts arose between efforts to protect the land and the rights of indigenous people.

In 1948, the Serengeti National Park was created, but to allow the Maasai people to live there, the Ngorongoro Conservation Area was separated from the park in 1959. Maasai people living in Serengeti were moved to the Ngorongoro Conservation Area, increasing the number of Maasai there. This led to more disagreements between the Tanzanian government and the Maasai.

The Ngorongoro Conservation Area Authority (NCAA) was formed in 1959 to manage the area. It works to protect the land while supporting the traditions of the Maasai people and promoting tourism. The NCAA also aims to preserve the natural and cultural values of the region.

In 1979, the Ngorongoro Conservation Area was added to the UNESCO World Heritage List for its natural beauty and wildlife. In 2010, it received Mixed Heritage Status because of the cultural importance of Olduvai Gorge, though the Maasai community was not included in this recognition. This has contributed to ongoing conflicts about how the area is used and managed.

The Wildlife Conservation Act of 2009 limited human activities in the Ngorongoro Crater and created rules that made it harder for traditional Maasai herders to live there. The International Union for Conservation of Nature (IUCN) is working to find solutions that help both conservation efforts and local communities.

In 2021, the Tanzanian government began planning to move all Maasai people living in the Ngorongoro Conservation Area to Msomera, a village 600 kilometers away. The government calls this a voluntary move, but Human Rights Watch reports that the process has been forced, without following the principle of free, prior, and informed consent (FPIC).

Geography

The Serengeti ecosystem includes several protected areas in Tanzania. The Ngorongoro Conservation Area (NCA) is located in the southeast (shown in dark grey). The NCA is next to the Serengeti National Park to the northwest and connects with the southern Serengeti plains of the park. These plains also extend north of the NCA into the unprotected Loliondo division. The area remains open for wildlife because the Maasai people practice a type of farming called transhumance pastoralism, where they move their animals to find grass. The south and east of the NCA are volcanic highlands, including the famous Ngorongoro Crater and the less well-known Empakaai Crater.

The southern and eastern edges of the Serengeti ecosystem are marked by the edge of the East African Rift wall. This natural feature stops animals from migrating in those directions. On the map, Lake Nyanza is the same as Lake Victoria within the Serengeti Ecosystem.

The Pliocene Ngorongoro volcanic group includes eight inactive shield volcanoes in the Eyasi half-graben, which is bordered by the Gregory Rift Western Escarpment on the east. The Lake Eyasi escarpment forms the southwest boundary of the half-graben. Within this area, five volcanoes have dome-shaped tops, while three have large, bowl-shaped depressions called calderas. The Ngorongoro Volcano (2.5–1.9 million years old) is mainly made of basaltic trachyandesite. The caldera is fed by the Munge and Oljoro Nyuki Rivers, and the Ngoitokitok hot springs flow into the Goringop swamp. Lake Magadi is a shallow, alkaline lake that is 1.7 meters deep. Other volcanoes in the area include Olmoti (2.01–1.79 million years old), Empakaai, Loolmalasin, Sadiman (3.7 million years old), Lemagrut, and Oldeani. The northwest part of the NCA includes the Serengeti Plains, the Salei Plains, the Oldupai Gorge, and the Gol Mountains inselbergs. These inselbergs are made of quartzite and mica schist, which are about 800 to 500 million years old.

Ngorongoro Crater

The main feature of the Ngorongoro Conservation Area is the Ngorongoro Crater, the largest inactive, intact, and unfilled volcanic caldera in the world. The crater formed when a large volcano erupted and collapsed on itself about two to three million years ago. It is 610 meters (2,000 feet) deep, and its floor covers 260 square kilometers (100 square miles). Experts estimate the original volcano was between 4,500 and 5,800 meters (2.8 to 3.6 miles) tall. The crater floor is 1,800 meters (5,900 feet) above sea level. In February 2013, the crater was chosen as one of the Seven Natural Wonders of Africa by the Seven Natural Wonders organization in Arusha, Tanzania. The Ngorongoro volcano was active from about 2.45 to 2 million years ago. Volcanic eruptions like the one that formed the Ngorongoro Crater were common in the region. Similar collapses happened at Olmoti and Empakaai, but these were smaller in size and effect. Two recent volcanoes near Empakaai, Kerimasi and Ol Doinyo Lengai, are still active. Ol Doinyo Lengai had major eruptions in 2007 and 2008, and smaller eruptions continue to slowly fill the crater. The name "Ngorongoro" in Maasai means "Mountain of God." The Munge Stream flows from Olmoti Crater to the north and is the main water source that drains into a seasonal salt lake in the center of the crater. This lake is called "Makat" by the Maasai, meaning "salt," and "Magadi" by others. The Lerai Stream flows from the humid forests to the south of the crater and feeds the Lerai Forest on the crater floor. When there is enough rain, the Lerai Stream also flows into Lake Magadi. Water use by lodges and the Ngorongoro Conservation Area headquarters reduces the amount of water entering Lerai by about 25%.

Another major water source in the crater is the Ngoitokitok Spring, located near the eastern crater wall. This area has a picnic site for tourists, a large swamp fed by the spring, and is home to hippos, elephants, lions, and other animals. Many small springs are found around the crater floor, and these are important water sources for animals and the local Maasai, especially during droughts. Maasai people were once allowed to graze their cattle inside the crater, but this practice was stopped in 2015.

Olduvai Gorge

The Ngorongoro Conservation Area protects Olduvai Gorge, located in the plains area. This site is important because it is where the earliest known remains of the human genus, Homo habilis, and early human relatives, such as Paranthropus boisei, were discovered.

Olduvai Gorge is a deep valley in the Great Rift Valley, which runs along eastern Africa. It is found in the eastern Serengeti Plains of northeastern Tanzania and is about 50 kilometers (31 miles) long. The area is dry because it is in the rain shadow of the Ngorongoro highlands, making it the driest part of the region. The name "Olduvai" comes from the Maasai word "Oldupaai," which refers to a wild sisal plant called Sansevieria ehrenbergii.

Olduvai Gorge is one of the most important places in the world for studying prehistoric life. Research there has helped scientists learn more about early human evolution. Excavations began in the 1950s by Mary and Louis Leakey and continue today by their family. Some scientists believe the area was once a large lake. Over time, volcanic ash from eruptions covered the lake's shores. About 500,000 years ago, earthquake activity changed the path of a nearby stream. This caused the stream to cut through the layers of ash and sediment, revealing seven distinct layers in the sides of the gorge.

Wildlife

Approximately 25,000 large animals, mostly hoofed animals called ungulates, live in the crater. Large mammals in the crater include the black rhinoceros (Diceros bicornis michaeli). The local population of this animal decreased from about 108 in 1964–66 to 13 in 1993. Because of monitoring and protection efforts by the Frankfurt Zoological Society, International Rhino Foundation, and World Wildlife Fund, the current total is 55 animals as of 2018.

Other large mammals in the crater include the African buffalo or Cape buffalo (Syncerus caffer) and the hippopotamus (Hippopotamus amphibius). Many other ungulates also live in the crater, such as the blue wildebeest (Connochaetes taurinus), estimated to be 7,000 in 1994; Grant's zebra (Equus quagga boehmi), estimated to be 4,000; the eland (Taurotragus oryx); Grant's (Nanger granti) and Thomson's gazelles (Eudorcas thomsonii), estimated to be 3,000; and waterbucks (Kobus ellipsiprymnus), which are mainly found near Lerai Forest.

Giraffes, impalas (Aepyceros melampus), topis (Damaliscus lunatus), oribis (Ourebia oribi), and crocodiles (Crocodylus niloticus) are not found in the crater.

Cheetahs (Acinonyx jubatus raineyi), East African wild dogs (Lycaon pictus lupinus), and African leopards (Panthera pardus pardus) are rarely seen in the crater. Spotted hyenas (Crocuta crocuta) have been studied in the NCA since 1996.

Although the crater is considered a natural enclosure for many types of wildlife, 20 percent or more of the wildebeest and half of the zebra populations leave the crater during the wet season. Cape buffalo (Syncerus caffer) stay in the crater, and their numbers are highest during the rainy season.

Since 1986, the wildebeest population in the crater has decreased from 14,677 to 7,250 between 2003 and 2005. The numbers of eland and Thomson's gazelle have also declined, while the buffalo population has increased greatly. This increase is likely due to the long prevention of fire, which favors high-fibrous grasses over shorter, less fibrous types.

Servals (Leptailurus serval) are widely found in the crater.

Lake Magadi, a large lake in the southwest of the crater, is often home to thousands of mainly lesser flamingos.

The crater has one mammal species that is found only in this area: Mduma's shrew (Crocidura mdumai). This shrew lives in montane forests near the edge of the crater and is considered endangered because of deforestation from smallholder farming.

The crater has one of the densest known populations of lions, numbering 62 in 2001.

A side effect of the crater being a natural enclosure is that the lion population is significantly inbred. This happens because very few new bloodlines enter the local gene pool, as very few male lions from outside the crater migrate in. Those that do enter are often driven out by the crater's existing male lions.

Long-term data show that lions in the crater were affected by four deadly disease outbreaks between 1962 and 2002. A drought in 1961 and heavy rains during the 1962 dry season led to a large increase in blood-sucking stable flies (Stomoxys calcitrans) by May 1962. These flies caused painful skin sores that became infected, reducing the lion population from 75–100 to 12. The population recovered to about 100 by 1975 and remained stable until 1983, when a decline began. Lion numbers have generally been below 60 since 1993, reaching a low of 29 in 1998. In 2001, 34 percent of the lion population died between January and April due to a combination of tick-borne disease and canine distemper.

The lion population is also affected by the takeover of prides by incoming males, which often kill small cubs. However, the biggest influence on the lion population appears to be disease, particularly canine distemper.

Outside Ngorongoro Crater

The Ngorongoro Conservation Area is home to many species of wildlife and the Masai people. Near the area, in the Ndutu Lake region, there are large numbers of cheetahs and lions. Common animals in the area include hartebeest (Alcelaphus buselaphus), spotted hyenas (Crocuta crocuta), and jackals. The number of African wild dogs may have decreased recently. Servals are often found on the plains west of the Ngorongoro Crater.

Each year, millions of large hoofed animals migrate through the conservation area. In December, about 1.7 million wildebeest, 260,000 zebras, and 470,000 gazelles enter the area. They leave in June. This movement happens seasonally, depending on rainfall, and the animals travel across most of the plains to find food.

Threats to the conservation area

The 2020 Conservation Outlook Assessment by the International Union for Conservation of Nature (IUCN) World Heritage Outlook points out these problems for the continued protection of the Ngorongoro Conservation Area (NCA):

• Growth in the population of the Maasai people, who are pastoralists (livestock herders)
• Making sure tourism and visits are managed in a way that doesn’t harm the environment

The NCA is special because it is the only conservation area in Tanzania that protects wildlife while allowing people to live there. The Maasai people who live in the NCA use the land in ways that avoid harming wildlife. For example, growing crops is only allowed for basic needs, not for large-scale farming.

In 1966, about 8,700 Maasai lived in the NCA. By 2017, this number had grown to 93,136, and it is expected to increase to 161,000 by 2027. This population growth causes other problems, such as more livestock, which may lead to overgrazing (using more land than it can support), cutting down trees for homes and buildings, and changes to the natural scenery from construction.

One possible solution is moving some Maasai to the village of Msomera, 600 kilometers (370 miles) away. This effort began in 2021. The Ngorongoro Conservation Area Authority provides money and land for homes, crops, and livestock to those who move. However, this plan has caused disagreements between people already living in Msomera and the new residents, and there are worries that everyone’s rights might not be protected.

The Ngorongoro Conservation Area Authority, which manages the NCA, depends heavily on money from tourism to protect the area and share income with local communities. If tourism decreases, this income could be lost. New tourism records were reported in 2024, with 752,232 visitors in the 2022/23 fiscal year.

Most tourists visit the Ngorongoro Crater, which is a small part of the NCA. To reduce traffic there, higher fees are charged for each vehicle, the number of vehicles allowed in the crater at one time is limited to 50, and vehicles are encouraged to carry more passengers. Tourist businesses must follow rules to reduce their impact on the environment.