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Material Related to Class Discussion of The Serengeti-Mara andEast Africa's Rift Valley Area |
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Click where you
see Click on Click on photos for enlargement. |
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Also See: [Two Peoples] |
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Contents: [Location and Habitat] [The Serengeti] [The Ngorongoro Conservation Area] [Migration] [The Serengeti Lions] [The Masai Mara in Kenya] |
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The African Continent and The Great Rift Click on maps for large view. The East Africa Triangle Northern Tanzania Safari Circuit The Serengeti-Mara Ecosystem |
Location The Great Rift Valley cuts a huge swath in the earth, from Lebanon to the Mozambique Channel, a distance of This giant "scar" is a truly amazing and mysterious feature. It contains the lowest point on land (the Afar
Depression, 510 ft below sea level), is flanked by some of the world's highest and biggest volcanic mountains
(including Mt. Kilimanjaro, the highest peak in Africa, at 19,340 ft), holds some of the world's largest lakes
(including Lake Malawi, one of the deepest lakes in the world) and provides a seaway between Europe and the
Orient (in the form of the Red Sea). |
HabitatThe ingredients of natural habitat are 1) proximity to the ocean and its warm moist air, 2) altitude and other topographical features, and 3) soil structure. Habitat vegetation ranges from sweeping grassland plains to original tracts of lush equatorial forest. Along the coast lies a flat, low-lying region with warm breezes from the Indian ocean. This fertile coastline gradually yields to higher altitudes of lush forest which receives abundant rainfall. Progressing westward into the interior the terrain changes dramatically to become the semi-arid Maasai Steppe, which comprises enormous grassland plains that seem to stretch to the horizon. The eastern arm of the Rift Valley in Tanzania, embracing the Ngorongoro Conservation Area and Lake Manyara, divides the steppe from the 1200-m-high (3,937 ft.) central plateau which makes up most of the rest of Tanzania. The Rift's western arm splits from its eastern counterpart to encompass Lake Tanganyika. In the east, below Kilimanjaro, a series of mountain ranges curves east, then turns south and eventually southwest. This mountainous spine preserves precious traces of equatorial forest that used to extend right across Africa. The predominant vegetation on the central plateau and in the southwest is woodland, composed of a grassland belt with mainly tropical deciduous tree cover. The Maasai Steppe is open grassland with Acacia-commiphora woodland. In some places such as Tarangire the vegetation is more varied and includes bushland of commiphora, acacias, and giant baobobs. Coastal vegetation includes coconut palms, introduced casuarinas, and tracts of mangroves. |
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Serengeti Habitats
The Serengeti is comprised of several habitat types: the short and long grass open plains in the southeast, the acacia savanna in the central Serengeti, the hilly and more densely wooded northern section, and the mountainous and densely wooded western corridor. Along the margins of these areas, and especially in the central Serengeti there are many ecotones or blending zones of habitats. Each habitat type supports its complement of animal life: wildebeest, zebra, antelopes and other antelope types frequent the grassy plains, giraffes almost exclusively in the acacia woodland, elephants on the margin of savanna and woodland. Predators follow their preferred food source.
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"The name Serengeti conjures up images of one
of the last remaining wildlife spectacles on earth. Those lucky enough
to visit this wilderness area come away with memories of vast herds of
antelope feeding on the plains, columns of wildebeest, head to tail,
trudging along their traditional migration routes, and prides of lions,
sometimes sleeping, sometimes alert and carefully stalking their prey.
The extensive grasslands are interspersed with 'kopjes' - rocky outcrops
like islands in the flat plain, each with their own wildlife
communities. Rivers flow through the Park, providing habitats for a
variety of birds, mammals, and reptiles.
"The Serengeti is one of the largest wildlife sanctuaries in the world, and the commitment to its preservation shown by the government of Tanzania is important in a country faced by land shortage and a rising population." Lota Melamari, Director General, Tanzania National Parks. Whistling thorn or ant-galled acacia dominates the drier
wind-swept plains. It has a symbiotic relationship to the ants which
inhabit its galls. |
Serengeti National Park is nearly 15,000 square kilometers, the largest park in Tanzania and one of the largest in the world. The name comes from a Maasai word meaning "endless plains". And that indeed describes a major component of this ecosystem. The concentration of plains animals which gathers before migrating north is world renowned and unparalleled anywhere else on the planet. As we approached the Serengeti from the east, coming down from the Ngorongoro highlands, our first view, as far as the eye could see, was the short grass plains. These plains are interrupted intermittently by copjes, an Afrikaans word for the rocky outcrops of granite. Pronounced copy, they have been eroded and weathered into rough and jumbled islands which stand out from the surrounding plain, where volcanic dust and ash has leveled the landscape.
The kopjes are habitat islands which provide refuges from the open plains for many plants and animals. [Copje panorama] |
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Migration |
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Dry Season Rainy Season |
During the rainy season, from November through May,
the plains are the feeding ground for immense herds of wildebeest,
zebras, gazelles, and numerous others such as ostriches, eland, topi,
hartebeest etc. But when the dry season begins and the grass
withers, many of these animals, especially the wildebeest and zebra,
must move on. This movement takes them
generally north and west, where there is permanent water and
thunderstorms more frequent. By the end of the dry season in July, most
have ended up in the Maasai Mara in Kenya
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The Sound of Migration
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The wildebeest is the
dominant herbivore in the Serengeti ecosystem. Its migratory population
ranges over a region of about 25,000 sq. km., of which about two thirds
is in the national park, the NCA, and the Kenya Maasai Mara Reserve.
Wildebeest are very efficient grazers, so much so that they exhaust the
available grass and must constantly move on to greener pastures. In May
and June lines of wildebeest up to 40 km long have been observed heading
north and west to the woodland areas.
It is also during this period that most of the cows are bred. Bulls can be seen and heard rounding up cows, cutting out bachelor males and bashing heads with territorial neighbors in an all out effort to breed with as many females as possible. Eight and a half months later the cows drop their calves after migrating back to the short grass plains. The vast majority of the calves are born during a two to three week period, providing so many calves that predators are overwhelmed and plenty are left over. The predators give birth to their young during this period as well, taking advantage of the abundant food supply. Populations of both predators and prey benefit from this adaptation. Another adaptation of the wildebeest is the prodigious ability to stand and run with the herd after only a few days. |
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Burchell's, or plains zebras, although
only one-sixth the numbers of the wildebeest in the Serengeti are still important in the the migration,
and in the grazing hierarchy. Zebras move in family units
containing up to a dozen females and young, and bachelor herds of mainly
immature males. Each family is controlled by a stallion, who
defends it against potential rivals as well as against predators. Most
foals are born in December and January during the wet season. Mares also
cooperate in defending the family and protecting foals against
predators, and remain in the herd in which they first became pregnant and
foal. Because of their cooperation, hyenas hunt in packs against zebras rather
than singly as they do with antelopes.
Left: Zebras like to roll in dust. |
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Grazers and Browsers The Predators |
The Grazing Succession:
A great variety of grazers
can coexist on the Serengeti plains and adjacent habitats because each
species occupies a slightly different, yet complementary niche. There is
a grazing succession in which heavy grazers such as elephants, buffalo,
and hippos eat and trample the large coarse grasses, paving the way for
lighter grazers such as zebras, topi, and wildebeest who in turn give
way to the lightest grazers, the gazelles and warthogs.
Above: Dik-dik, Ed Shelley |
Below: Elephants enjoy browsing on the tall coarse grasses. (John and Sandy Murdock) Above: An Elephant family lines up to drink at a Serengeti water hole. |
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| The Seronera area is famous for the leopards, lions, and cheetahs which can usually be seen without difficulty. Leopards are usually seen in the branches of sausage or acacia trees near a watercourse. They often carry their prey up into the branches to get it away from other predators. They are solitary creatures, the male only associating with the female when she is in estrous. In the Seronera Valley leopards are known for being relatively placid, in contrast to their usual demeanor. They are always dangerous when they are with cubs. | |||
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Male lion, Sherry Sybesma Two lions yawning, Jim Swan |
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You can readily distinguish the males from the females in a pride by their manes and larger size, and if you spend some time watching you can soon recognize individuals. Most lions have scars on their faces and ears, and some may have broken teeth. Also, the pattern of the 'whisker spots' is unique to each lion and is useful for identification because it never changes. Scientists in the Serengeti have specifically identified more than 200 individuals by these methods. | ||
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The Masai Mara in Kenya* |
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Nowhere embodies the symbol of wild places better
than the Mara-Serengeti ecosystem, a vast tract of land lying astride
the Kenya-Tanzania border - a far-off place steeped in mystery. Two million years ago man’s early ancestors moved onto the plains to eek out a living as hunterer-gatherers. In more recent times Masai herdsman have staked their claim to the grasslands, moving with the livestock according to the seasons, following the rains just like the migratory herds When the rains disappear in the Serengeti, the
wildebeest and zebras move north, following the rains into the Mara.
It was the Masai, the nomadic
cattle people of the East African plains, who named the sea of grass
between the Isuria escarpment and the Loita Hills. |
The Masai Mara National Reserve is by far the best known
and most beautiful of
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For two hundred years this was the home of the Masai, but towards the end of the last century their cattle were annihilated by rinderpest and the tribe itself was stricken by smallpox. Soon the Maasai clans were scattered. Their enkang-iti (stockaded villages) lay empty and the land reverted to the wild
This was the Mara that the
first Europeans saw: an earthly paradise inhabited only by teeming herds
of game and a few honey hunters. The next few decades saw the heyday of
the professional hunters, the Out of Africa era of Denys Finch Hatton
and Karen Blixen, when rich westerners would pay handsomely for the
chance to bag a black-maned Mara lion. After the Second World War the Mara lay wide open to
exploitation. Shooting became an uncontrolled free-for-all and, with the
gradual return of the Masai, cattle encroached as far as the tsetse fly
would allow. But in 1948 the Mara Triangle - 520 square kilometers of
land between the Isuria escarpment, the
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In 1961 a further 1300 square kilometers was added and the whole area became the Masai Mara National Reserve. It happened just in time. When the killing stopped in that year fewer than ten male lions remained on the Keekorok Plains. In 1984, bowing to pressure from the Masai for the return of vital water holes and dry-season grazing grounds, the government de-gazetted 162 square kilometers of the reserve, effectively reducing the size of the Mara by one-tenth. Since then other changes have overtaken Masailand. The modern world is closing in. Today,
the Mara is one of the most popular tourist destinations in |
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| *Text and map in the above section is taken from Jonathan Scott and Brian Jackman, The Big Cat Diary: A Year in the Masai Mara, BBC Books. | |||||
The Ngorongoro Conservation Area |
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Ngorongoro Photos:
Tourism: Fees paid by visitors go toward maintenance and improvement of facilities and services. Fees also go to the central government and are an important source of foreign exchange. Education and Research: Scientists from throughout the world come to the NCA for research in anthropology, wildlife biology, botany, geology and other disciplines.
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The NCA includes a large area (3200 sq. miles) of interrelated ecosystems consisting of the Crater Highlands (Ngorongoro Crater and surrounding uplands) vast plains, bush and woodland, swamps, lakes and rivers. The plains are part of the great Serengeti ecosystem and many animals move freely from one area to another. Climate: Distinct wet and dry seasons characterize the area with most of the rain falling from April to May. Rain in any given area can be quite variable depending on topography and yearly differences. Prevailing winds bring moisture from the Indian Ocean to the east and south sides of the highlands, with the driest areas being the plains and Olduvai gorge in the "rain shadow". From June through October it is mostly dry everywhere. Cold weather sets in during June and July, especially in the highlands, producing dense fog around the crater rim while the crater floor has clear sunny weather. Protection Status: The NCA is an example of multi-use protection, administered by an independent body, the NCAA (Ngorongoro Conservation Area Authority) whose purpose is to protect and integrate the following diverse values and interests: Wildlife: all wildlife is protected throughout the NCA. Hunting for sport is not allowed and strenuous efforts are made to prevent poaching. An endangered species, the black rhino, occupies the crater. Forestry: The Northern Highlands Forest Reserve protects the natural forest which occurs on the southern and eastern slopes of the highlands. This forest is important as watershed and soil conservation. Agriculture around Lake Eyasi and Lake Manyara depends on the groundwater springs resulting from rain in the highlands. |
Ngorongoro Crater,
at about 20 km in diameter, is one of the world's largest
calderas (a collapsed volcano). Its steep sides, permanent water
supply, and surrounding intensive agriculture have reduced migration
for many of its species. Many of those that can move freely in and out
of the crater tend to stay there to enjoy its lush conditions. For this reason it is one of Tanzania's premier
and most visited wildlife viewing areas. This has led some to call it
little better than a drive-through zoo. We found it to be a spectacular
setting for up close observations of animals and their behavior. The
wildlife is certainly habituated to vehicles. Because of this we felt like
the proverbial "fly on the wall", the animals behaving as
if we weren't there.
Because of isolation and other factors the crater's lion population has been adversely affected in recent years. Much research has been done and is continuing on the lion populations of the NCA and Serengeti. [See The Lions of Ngorongoro Crater ] and [The Crater Lions PBS] People: Wildlife doesn't have the crater to itself. Local Maasai tribes still bring their cattle into the crater to obtain salt. This practice is scheduled to end soon. Traditionally nomadic, the Maasai have been making permanent settlements in and around the NCA, and supplementing their traditional diet of milk, blood, and meat with grain. Until 1992 no cultivation was allowed within the conservation area. Limited cultivation is now permitted but is scheduled to be phased out. Anthropology: The NCA includes Olduvai Gorge where in 1959 Mary Leaky discovered Zinjanthropus (Australopithecus boisei) and Laetoli, where the first human trackway was discovered. These and other stone age sites are protected by the NCAA.
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Images of Ngorongoro: Click on images and hypertext for the big picture. |
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Who can forget the hippo pool with hippos lazing around, lions alert or rolling around, storks, ibises, crowned cranes, even a buffalo stuck in the mud. And nearby, elephant, zebras, buffalo, warthogs and who knows what else are running and cavorting. Even an elephant chasing lions away. It's a panoply of wildlife. |
And the lush grass plains with herbivores such as wildebeest, Thompson's gazelles, Grant's gazelles, zebra, along with jackals, hyenas, and lions to prey on them. |
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