The area of savannah and open woodland comprises some 1.5 million hectares and contains the largest herds of grazing animals in the world and the carnivores that prey on them, providing a wildlife spectacle that is second to none. The great migrating herds are continuously moving through the entire ecosystem, but the sight is most impressive in May and June, when the animals travel en masse from the central plains to the permanent water holes on the western side of the park. The Serengeti ecosystem contains much more than these dominant species.
The annual migration is dominated by wildebeest in enormous numbers – some 190,000 in the 1950s, 1.69 million in 1989, but 1.27 million in 1991; also by Burchell’s zebra (some 200,000), Thomson’s gazelle, with some eland and topi, each harvesting the grass most suited to it. The herds are followed by prides of lion numbering up to 3,000 individuals, spotted hyena, striped hyena, golden jackal, side-striped jackal and black-backed jackal. The last packs of the endangered wild dog disappeared in 1991. A rabies epidemic killed three of the packs, but there is no agreement on the full cause of the disappearance.
There are large herds of antelope of many species. On the grasslands are eland, lesser kudu, roan antelope, oribi, Grant’s gazelle, hartebeest, steenbock, topi and oryx, also buffalo. In the woodlands are grimmia, impala and Kirk’s dikdik. In the swamps are reed-buck and water-buck. Among the kopjes are klipspringers, as well as giraffe and olive baboon; and on the mountains, mountain reedbuck.
Other characteristic larger mammals are leopard, cheetah (classed as vulnerable), caracal, African elephant (endangered: estimated number 1,357 in 1994), black rhinoceros (critically endangered: there are very few left), hippopotamus and giraffe. Smaller mammals include numerous species of bat, bush baby, vervet monkey, patas monkey, black and white colobus monkey and olive baboon, aardvark, ground pangolin, cape hare, porcupine, three species of hyrax and many other rodents, bat-eared fox, two species of otter, ratel, zorilla, common genet, large spotted genet, African civet, seven species of mongoose, aardwolf, serval, golden cat, African wildcat and bush pig. Reptiles include Nile crocodile, Nile monitor lizard, African rock python, black necked spitting cobra and puff adder.
Over 500 bird species include 34 raptors, 6 vultures and aggregations of over 20,000 water birds. There are ostrich, marabou stork, lesser flamingo, African fish eagle, tawny eagle, lesser falcon (vulnerable), secretary bird, helmeted guinea fowl, crowned crane, kori bustard, black-winged pratincole, black-winged plover, Caspian plover, white-winged black tern, Fischer’s lovebird, purpuratus, southern ground hornbill, grey-crested helmet shrike, Karamoja apalis (vulnerable), redthroated tit and several birds of restricted distribution such as rufous-tailed weaver.
Serengeti National Park is at the heart the larger Serengeti ecosystem, which is defined by the area covered by the annual migration. The property is contiguous with Ngorongoro Conservation Unit, an area of 528,000 hectares declared a World Heritage Site in 1979. The entire ecosystem also includes the Maswa Game Reserve (2,200 km2) in the south, Grumeti and Ikorongo Game Reserves in the east, Maasai Mara National Reserve in Kenya (1,672 km2) to the north, and Loliondo Game Controlled Area in the west.
This entire ecosystem is intact and no barriers hamper the migration. Serengeti National Park is sufficiently large and intact to ensure the survival and vigor of all the species contained therein, if maintained in its present state but does not, by itself, ensure the protection of the entire ecosystem. However, all other parts of the ecosystem do have a greater or lesser degree of protection. A potential threat is the plan to build a transport infrastructure through the Serengeti. This would essentially cut the ecosystem into two halves, with predictably negative consequences on the Serengeti. Adding Maswa Game Reserve and Maasai Mara National Reserve to the World Heritage List, or giving then the status of a buffer zone would further safeguard the Outstanding Universal Values of this property.
Another major potential threat to the integrity of the Park is the scarcity of surface water for the animals during dry years, as only one river (Mara) flows perennially through the Park. An extension of the Park boundary to reach Lake Victoria providing a corridor for animals to access water in times of drought is planned for the future to address this issue.