| Kenya
and Tanzania
in East
Africa have many different types of nature, or bioptopes. Mountain, lakes, rivers
and rifts are some obvious features that affect the local fauna and flora of an area.
Other local factors are altitude, soil and minerals, rainfall, groundwater levels etc.
This page describes some main types of nature that you may see while on safari in East
Africa.
Rain forest, savanna and desert
The African nature can (where it has not been transformed by farming or pastoralism)
very simplified be divided in rain forest, savanna
or desert/semi desert. Rain forest is found where rainfall is high, and desert/semi
where rainfall is low. In between lies savanna (which is, in short, an area where grass
grows on the ground).
Besides these basic types of nature, there are many variations, such as mountains with
different flora at different altitude, and different flora on the wind-side and lee-side.
There are coastal environments with beaches or mangroves, marshes, gallery forests lining
rivers etc. The boundaries between biotopes are rarely sharp, but usually transition
zones with a mix of components from the surrounding biotopes. The transition zones can
even be regarded as separate biotopes.
Wildlife habitats
Many animal species are more or less adapted to living in a certain habitat. The hippopotamus,
for example, needs to spend its days in water (a river, lake or pool) to escape the
sunrays, and it needs grass on land to graze at night. If either water or grass is missing
in an area, you will not find any hippos there.
Other species are more flexible and may do well in many different biotopes. For example
elephants and leopards are found in varying environments, ranging from semi deserts
to montane forests. The elephant may even walk long distances and move between biotopes
to fill its needs.
Animal behaviour due to habitat
The behaviour of animal species is adapted to the kind of biotope they live in. Grazing
species mostly prefer open land, live in herds and react to threats by running away
from them. These species are not very territorial, and thus not very aggressive, as
food (grass) is available everywhere around. An example of such species is the white
rhinoceros (or grass rhino).
Species that eat leaves, i.e. browsers, live in habitats of shrubs and trees. These
food sources are less abundant and less evenly distributed compared to grass in grasslands,
and can support fewer individuals. Browsers therefore live in smaller groups or as solitaries,
and defend their territories to protect their food resources. As a result, they are
more aggressive. An example of such species is the black rhinoceros (or browse rhino).
Other browsers, such as the tiny dikdiks, are not aggressive, but depend on camouflage
and hiding for escaping threats, and on long-term male-female relationships for safeguarding
territories.
Animal whereabouts
When visiting a park
that has more than one biotope, you may find different species depending on where in
the park you go. Grazing zebras and wildebeest are found in open grassland or savanna,
while giraffes, eating shoots from trees and shrubs, are found in shrub- or woodland,
or in patches of acacias on savanna. Vervet monkeys may be found in trees close to water,
while blue monkeys prefer trees in areas with closed canopies, i.e. forests. The typical
picture of a leopard shows the cat resting on a branch in a big tree, and such trees,
often lining rivers or lakes, are the place to look for it during daytime. To find hippopotamus,
you need to look in the water (but keep an eye on land, too, not to run into a potentially
aggressive hippo out for a stroll).
Human activities
Human activities affect nature and the wildlife. For example, the city of Arusha
in northern Tanzania is situated in an area that used to
be good grazing grounds for wild animals, but is now over-grazed by Maasai
cattle and goats. Antelopes and other wild herbivores
are seen on rare occasions only. In other areas, trees are cut down for firewood or
to make room for crop fields, making it impossible for animals that depend on the trees
to remain in that area.
Savanna
The word 'savanna' is often used to describe not a single biotope, but rather open African
landscapes in general.
More precisely, the East African savanna is a tropical open grassland with scattered
shrubs or trees, and with an annual rainfall ranging from 200 mm/8 in to 1,500 mm/60
in. The rainfall is concentrated to one or two rainy seasons per year, with dry seasons
in between. Besides rain, factors creating the biotope are grazing by animals, bush
fires and soil types.
But for safaris, a 'savanna' may be more generally defined as an area where grass is
growing on the ground, thus ranging from pure grassland to woodland.
Acacia savanna
The acacia savanna of East Africa is often seen in nature documentaries. It's dominated
by open grassland, broken by patches of flat-top acacias or other acacias where underground
water supplies are sufficient to support such vegetation, or along rivers, where yellowed-barked
acacias and sausage trees are common. Other trees, such as the baobab, may be able to
store water and can do well in drier areas.
The acacia savanna is a fairly varied habitat, where many mammal species may live, ranging
from both grazing (for example zebras) and browsing (for example giraffes) herbivores,
to the big cats.
Savanna grassland
Grassland is found where rainfall or groundwater is too sparse to support shrubs and
trees. Open grassland areas are found in parts of many parks. A park known for its open
grassland is Masai Mara in Kenya.
Another type of grassland is found in southern Serengeti
in Tanzania. Beneath the thin soil, a hard layer of ash and lava from volcanoes east
of these vast grasslands prevents shrubs and trees from thriving, while the grass is
doing well.
Savanna grassland is home to grazing herbivores (for example gazelles, wildebeest and
zebras) and to some predators (for example cheetahs and
lions).
Savanna woodland
Savanna woodland (and shrubland) is more densely vegetated than acacia savanna or
grassland, but not densely enough to form a closed canopy. The open canopy allows sunlight
to reach the ground, allowing grass to grow.
This is a habitat suited to herbivores living in smaller herds or family groups, such
as impala antelopes, giraffes and Grevy's zebras (a zebra species found in northern
Kenya). But also larger herds may be seen, for example the vast herds of wildebeest
and common zebras, the so called migration,
crossing the woodlands and shrublands of northern Tanzania while migrating between Masai
Mara and Serengeti.
Miombo woodland
Safari literature uses miombo and mopane to describe two woodland types
found in central and southern Africa. Miombo (covering much of Zambia
and Zimbabwe, as well as parts of south-western Tanzania) has high rainfall (9001 500
mm/3560 in) and deciduous trees (i.e. trees dropping their leaves during dry seasons)
that are often thick-barked. Brachystegia is a dominant tree genus. Canopies
may be closed, and grasses may grow up to 3.5 m/11.5 ft high during the rainy seasons.
Mopane woodland
Mopane is drier (300900 mm/1235 in of annual rain) and has up to 1 m/3 ft
high grass. It's common from central Zambia westwards to Angola, and southwards to South
Africa. The name mopane comes from the African tree Colophospermums mopane,
which prefers dry and warm areas, and altitudes below 1,200 m/4,000 ft.
Forests
Forests are areas where water (and other local factors) is abundant enough to support
trees growing densely enough to form closed canopies. The water may come from rain,
clouds/mist, rivers or groundwater.
Rain forest
The tropical rain forest is a lowland forest receiving 1,500 mm/60 mm or more of annual
rainfall, distributed during the whole year. There are no rainy or dry seasons. The
trees grow high, and the undergrowth in forests undisturbed by human activities is not
very dense. In East Africa, rain forests are found only in western Uganda,
apart from a few remaining patches still remaining in other parts.
Montane forest
Montane forests remind of rain forests, but are not as high, have smaller leaves and
are found in cooler mountain areas where clouds and mist supply water. Such forests
may be found at altitudes above 1,500 m/5,000 ft, and are often evergreen on the wind-side,
but deciduous on the drier lee-side. A good example are the Ngorongoro
Highlands, where the vegetation differs very clearly from the eastern wind-side
to the western lee-side.
Above the tree line, montane forests are succeeded by different types of open biotopes,
where moisture and other factors decide the composition of the vegetation. Macro vegetation,
for example giant lobelias, are found at higher altitude on East African mountains such
as Mount Kenya and Kilimanjaro,
while open grasslands may be found in drier mountain areas.
Montane forests are often home to endemic animals and plants (i.e. species found nowhere
else). These species have been isolated from other similar habitats by the non-montane
biotopes at lower altitudes, and have therefore been able to evolve independently. An
example of such a local endemic is a monkey called highland mangabey or kipunji (Rungwecebus
kipunji), which was recently discovered in a highland area in southern Tanzania.
It is not only a new species, but also a new genus (group of species). This monkey can
be found only there.
Gallery forest
A gallery forest grows next to a river or lake in a landscape that otherwise lacks forests.
The yellow-barked acacia (Acacia xanthophloea) is a common tree in gallery forests.
It used to be called fever tree, as it was wrongly associated with the many cases of
fever occurring in the areas where it grew. The true culprit was the mosquito, which
is a carrier of malaria and yellow fever, and which, like the tree, thrives close to
water.
Ground water forest
The northern part of Lake Manyara National Park in Tanzania
is dominated by a high forest, which reminds of a rain forest, but receives an abundant
supply of water from the high ground water table found in this area. In addition, a
number of local rivers and creeks provide surface water for a healthy wildlife population,
including the highest concentration of elephants in Tanzania, 700 individuals in roughly
100 km2/40 sq mi. The surface water is also beneficial to the local farming village
Mto wa Mbu, producing many vegetables and fruits, and even rice.
Gardens
The gardens in and around East African cities and towns are, like lodge gardens, rarely
visited by other mammals than the occasional monkey, rodent or mongoose. But the garden
environment itself, featuring both indigenous and exotic plants, can offer a rewarding
experience. Safari-goers travelling to East Africa from cooler parts of the world may
enjoy the huge stands of bamboo, avocado and mango trees, flowering jacarandas and colourful
hibiscus. Among the birds, sunbirds, garden bulbuls and weavers are often seen in gardens.
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