CLIMATE
WEATHER
Ø The
daily weather report carries information about the temperature, humidity and
rainfall during the past 24 hours. It also predicts the weather for the day.
Ø Humidity
is a measure of the moisture in air.
Ø The
weather reports are prepared by the Meteorological Department of the
Government. This department collects data on temperature, wind, etc., and makes
the weather prediction.
Ø Rainfall
is measured by an instrument called the rain gauge. It is basically a
measuring cylinder with a funnel on top to collect rainwater.
Ø The
maximum and minimum temperatures recorded may be the same for some of the days.
However, all the parameters are not the same on any two days. Over a week there
may be considerable variation.
Ø The
day- to-day condition of the atmosphere at a place with respect to the Temperature,
humidity, rainfall, wind speed, etc., is called the weather at that place.
Ø The
temperature, humidity, and other factors are called the elements of the
weather.
Ø The
maximum temperature of the day occurs generally in the afternoon while the
minimum temperature occurs generally in the early morning.
Ø All
changes in the weather are caused by the sun. The sun is a huge sphere of hot
gases at a very high temperature. The distance of the sun from the earth is
very large. Even then the energy sent out by the sun is so huge that it is the
source of all heat and light on the earth. So, the sun is the primary source of
energy that causes changes in the weather. Energy absorbed and reflected by the
earth’s surface, oceans and the atmosphere play important roles in determining
the weather at any place.
CLIMATE
The
average weather pattern taken over a long time, say 25 years is called the
climate of the place.
CLIMATE
AND ADAPTATION
Climate
has a profound effect on all living organisms. Animals are adapted to survive
in the conditions in which they live. Animals living in very cold and hot
climate must possess special features to protect themselves against the extreme
cold or heat. The tropical and the Polar Regions are the two regions of the
earth, which have severe climatic conditions.
(i)
The polar regions
·
The Polar Regions present an extreme
climate. These regions are covered with snow and it is very cold for most part
of the year. For six months the sun does not set at the poles while for the
other six months the sun does not rise. In winters, the temperature can be as
low as –37°C. Animals living there have adapted to these severe conditions
·
Polar bears have white fur so that they
are not easily visible in the snowy white background. It protects them from
their predators. It also helps them in catching their prey. To protect them
from extreme cold, they have two thick layers of fur. They also have a layer of
fat under their skin. In fact, they are so well-insulated that they have to
move slowly and rest often to avoid getting overheated. Physical activities on
warm days necessitate cooling. So, the polar bear goes for swimming. It is a
good swimmer. Its paws are wide and large, which help it not only to swim well
but also walk with ease in the snow. While swimming under water, it can close
its nostrils and can remain under water for long durations. It has a strong
sense of smell so that it can catch its prey for food.
·
Another well-known animal living in the
Polar Regions is the penguin. It is also white and merges well with the white
background. It also has a thick skin and a lot of fat to protect it from cold.
Penguins huddle together to keep warm. Like polar bears, penguins are also good
swimmers. Their bodies are streamlined, and their feet have webs, making them
good swimmers.
·
Other animals living in the Polar Regions
are many types of fishes, musk oxen, reindeers, foxes, seals, whales, and
birds. It is to be noted that while fish can remain under cold water for long,
birds must remain warm to survive. They migrate to warmer regions when winter
sets in. They come back after the winter is over.
·
Some migratory birds travel as much as
15000 km to escape the extreme climatic conditions at home. Generally, they fly
high where the wind flow is helpful, and the cold conditions allow them to
disperse the heat generated by their flight muscles. But how these birds travel
to the same place year after year is still a mystery. It seems that these birds
have a built–in sense of direction and know in which direction to travel. Some
birds probably use landmarks to guide them. Many birds may be guided by the sun
during the day and stars at night. There is some evidence that birds may use
the magnetic field of the earth to find direction. And it is not only birds
that migrate; mammals, many types of fish and insects are also known to migrate
seasonally in search of more hospitable climates.
(ii)
The tropical rainforests
·
The tropical region has generally a hot
climate because of its location around the equator. Even in the coldest month
the temperature is generally higher than about 15°C. During hot summers, the
temperature may cross 40°C. Days and nights are almost equal in length
throughout the year. These regions get plenty of rainfall. An important feature
of this region is the tropical rainforests. Tropical rainforests are found in
Western Ghats and Assam in India, Southeast Asia, Central America and Central
Africa. Because of continuous warmth and rain, this region supports wide
variety of plants and animals. The major types of animals living in the
rainforests are monkeys, apes, gorillas, lions, tigers, elephants, leopards,
lizards, snakes, birds and insects.
·
The climatic conditions in rainforests are
highly suitable for supporting an enormous number and variety of animals. Since
the numbers are large, there is intense competition for food and shelter. Many
animals are adapted to living on the trees. Red-eyed frog has developed sticky
pads on its feet to help it climb trees on which it lives. To help them live on
the trees, monkeys have long tails for grasping branches. Their hands and feet
are such that they can easily hold on to the branches. As there is competition
for food, some animals are adapted to get food not easily reachable. A striking
example is that of the bird Toucan, which possesses a long, large beak. This
helps a toucan to reach the fruits on branches which are otherwise too weak to
support its weight.
·
Many tropical animals have sensitive
hearing, sharp eyesight, thick skin and a skin color which helps them to
camouflage by blending with the surroundings. This is to protect them from
predators. For example, big cats (lions and tigers) have thick skins and
sensitive hearing. The lion-tailed macaque (also called Beard ape) lives in the
rainforests of Western Ghats. Its most outstanding feature is the silver-white
mane, which surrounds the head from the cheeks down to its chin. It is a good
climber and spends a major part of its life on the tree. It feeds mainly on
fruits. It also eats seeds, young leaves, stems, flowers and buds. This beard
ape also searches for insects under the bark of the trees. Since it can get
sufficient food on the trees, it rarely comes down on the ground. Another
well-known animal of Indian tropical rainforest is the elephant. It has adapted
to the conditions of rainforests in many remarkable ways. Look at its trunk. It
uses it as a nose because of which it has a strong sense of smell. The trunk is
also used by it for picking up food. Moreover, its tusks are modified teeth.
These can tear the bark of trees that elephant loves to eat. So, the elephant can
handle the competition for food rather well. Large ears of the elephant help it
to hear even very soft sounds. They also help the elephant to keep cool in the
hot and humid climate of the rainforest.
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