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Deserts have come to symbolize for us places of extreme heat. The fact is, most of the famous deserts of
the world are places where the thermometer goes bubbling away and where the sun beats down without
mercy. But this does not mean that a desert must be a place where it is always hot. If you find out the
definition of a desert you will understand why this is so.
A desert is a region where only special forms of life can exist because there is a shortage of moisture.
In a 'hot' desert, there simply is not enough rainfall. So the definition holds true. But suppose there is a
region where all water is frozen solid and cannot be used by plants. This satisfies the definition too.
Only it would make this a 'cold' desert.
Many people do not know that much of the Arctic is really a desert. There is very little rainfall a
year, and most of the water is frozen. So it is quite properly called a desert. The great Gobi Desert in the
middle of Asia is bitterly cold in winter time.
Most of the dry, hot deserts with which we are familiar are found in two belts around the world,
just north and south of the Equator. They are caused by high atmospheric pressures that exist in those
areas which prevent rain from falling. Other deserts, which are found farther away from the Equator,
are the result of being in 'the rain shadow'. This is the name for an effect that is caused by mountain
barriers that catch rainfall on their seaward side and leave the interior region dry.
Deserts differ greatly in appearance. Where sand is abundant, the winds may build sand hills or
dunes. These are sand deserts. Rock deserts consist mostly of bare rock, which forms fantastic cliffs and
hills. No great rivers originate in deserts. But a river may rise in moist areas and cross great deserts on
its way to the sea. The Nile, for example, flows through the desert region of the Sahara.
The animals that exist in the desert are those that have managed to adapt themselves to its conditions. They must be able to do without water for long periods, or be able to reach water holes at great
distances. The camel, for example, is highly adapted to desert life. It has padded feet to walk on sand, a
water-storing stomach, humps of fat as a reserve supply of energy, and nostrils that can be closed to
keep out sand during windstorms.
Many of the smaller desert creatures need to drink no water at all. They get what liquid they need
from the sap of food plants and from night dew on leaves or stones.
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