Approximately 25,000 large animals, mostly ungulates, live in the crater. Large animals in the crater include the black rhinoceros (Diceros bicornis), the local population of which declined from about 108 in 1964-66 to between 11-14 in 1995, the African buffalo or Cape buffalo (Syncerus caffer), and the hippopotamus (Hippopotamus amphibius). There also are many other ungulates: the blue wildebeest (Connochaetes taurinus) (7,000 estimated in 1994), Grant’s zebra (Equus quagga boehmi) (4,000), the common eland (Taurotragus oryx), and Grant’s (Nanger granti) and Thomson’s gazelles (Eudorcas thomsonii) (3,000). Waterbucks (Kobus ellipsiprymnus) occur mainly near Lerai Forest. There are no topis (Damaliscus lunatus), oribis (Ourebia oribi), or crocodiles (Crocodylus niloticus). Impala (Aepyceros melampus) are absent because the open woodland they prefer does not exist. Giraffe also are absent, possibly because of a lack of browse species. Tanzanian cheetah (Acinonyx jubatus raineyi), East African wild dog (Lycaon pictus lupinus), and African leopard (Panthera pardus pardus) are rarely seen.
[accordion title=”Vacation” ]
Although thought of as “a natural enclosure” for a very wide variety of wildlife, 20 percent or more of the wildebeest and half the zebra populations vacate the crater in the wet season. Buffalo (Syncerus caffer) and eland do the opposite. Their highest numbers are during the rains.
Since 1986, the crater’s wildebeest population has fallen from 14,677 to 7,250 (2003-2005). The numbers of eland and Thomson’s gazelle also have declined while the buffalo population has increased greatly, probably due to the long prevention of fire which favors high-fibrous grasses over shorter, less fibrous types. Servals (Leptailurus serval) occur widely in the crater.
[accordion title=”Lake Magadi” ]a large lake in the southwest of the crater, is often inhabited by thousands of mainly lesser flamingoes.
[accordion title=”Lioness roars in Ngorongoro Crater, Tanzania” ]
The crater has one of the densest known population of Masai lions, numbering 62 in 2001.
A side effect of the crater being a natural enclosure is that the lion population is significantly inbred. This is due to the very small amount of new bloodlines that enter the local gene pool, as very few migrating male lions enter the crater from the outside. Those who do enter the crater are often prevented from contributing to the gene pool by the crater’s male lions, who expel any outside competitors.
Long-term data imply that lions in the crater were struck by four deadly disease outbreaks between 1962 and 2002. Drought in 1961 and rains throughout the 1962 dry season caused a massive build-up of blood-sucking stable flies (Stomoxys calcitrans) by May 1962. They drained blood and caused painful skin sores that became infected, causing lion numbers to crash from 75-100 to 12. The population recovered to around 100 by 1975 and remained stable until 1983, when a persistent decline began. Numbers have generally remained below 60 animals since 1993, reaching a low of 29 in 1998. In 2001, 34 percent of the lion population died between January and April from a combination of tick-borne disease and canine distemper.
The lion population is also influenced to some extent by the takeover of prides by incoming males, which typically kill small cubs. The biggest influence, however, appears to be disease, particularly canine distemper.