Serengeti National Park
Serengeti National Park
Serengeti National Park lies in northern Tanzania between Lake Victoria and the East African Rift Valley. It was established in 1929 (and expanded in 1940) to protect 5,600 square miles (14,500 sq. km) of the Serengeti plains ecosystem . This vast park spans an area twice the size of Yellowstone National Park and supports over 94 species of mammals, 400 species of birds, and includes the spectacular migration routes of the largest herds of grazing animals to be seen anywhere in the world.
Each year, migrating herds move clockwise around the Park, constantly seeking better feeding grounds. Changing water availability is the key factor in the annual migrations, which correlate closely with the local cycles of rainfall. At the right time of year, visitors to the Park can see hundreds of thousands of migrating herds of wildebeest (Connochates taurinus ), running in winding lines several miles long. The wildebeest are accompanied by herds of zebra (Equus burchelli ) and Thomson's gazelle (Gazella thomsoni ).
During the peak dry season (August to November), the grazers congregate in the Serengeti's northern extension, moving south east when the first storms appear in December. The greatest concentration of animals occurs in the short grass pastures of the eastern Serengeti from December to May when millions of the Park's migratory grazers assemble. They are accompanied by packs of nomadic predators such as lion (Panthera leo ) and hyenas (Crocuta crocuta ). As the dry season progresses (June and July) and the grazing gets worse, the massive herds move to the wooded savannas of the western corridor of the Park. By mid-August, when this food supply is exhausted, the herds move back into the northern plains, crossing also into the adjacent Masai Mara National Reserve in Kenya.
The non-migrant inhabitants of the Serengeti plains include ostrich (Struthio camelus ), impala (Aepyceros melanious ), topi (Damalicus korrigum ), buffalo (Syncercus kaffer ), giraffe (Giraffa camelopardalis ), Grant's gazelle (Gazella granti ), leopard (Panthera pardus ), cheetah (Acinonyx jubatus ), hunting dogs (Lycaeon pictus ), and jackals (Canis adustus ).
The three principle species of migratory grazers—zebra, wildebeest, and Thomson's gazelle—do not compete directly for food, and it is common to find them grazing together. Zebras eat the upper parts of the grass shoots, exposing the softer leaf bases for the wildebeest. Grazing wildebeest in turn expose the herb layer beneath the grass, which is eaten by gazelles. Balanced populations of grazers actively maintain the stability of grassland ecosystems: too little grazing will allow woody vegetation to grow, while too much grazing will turn grassland into desert .
Today, the Serengeti National Park is under pressure from the rapidly growing human population outside the Park. Domestic cattle herders and farmers operate inside Park boundaries, competing with the wildlife for food, water, and land, while well-armed poachers kill game for meat, horns, and tusks. Human ancestors (Australopithecus robustus and Homo habilis ) once hunted game on the Serengeti plains, as evidenced by the finds of the Louis and Mary Leakey at Olduvai Gorge, which lies close to the Park's eastern entrance.
[Neil Cumberlidge Ph.D. ]
RESOURCES
BOOKS
A Field Guide to the National Parks of East Africa. London: J. G. Williams, Collins, 1981.
Schaller, George B. Golden Shadows, Flying Hooves. Chicago: University of Chicago Press, 1970.