7 weather, climate and animal adaptations to climate

7
Weather, Climate and
Adaptations of Animals to
Climate

D
o you remember the things that
you were asked to pack when
you were heading for a hill
station? When the sky is cloudy, your
parents insist that you carry an
umbrella. Have you heard elders in your
family discuss the weather before Fig. 7.1 A sample of a weather report from a
planning a family function? You must newspaper
have also heard the experts discussing
the weather before the start of a game.
Have you ever wondered why? The I wonder who prepares
weather may have a profound effect on these reports!
the game. It has a profound effect on
our lives. Many of our daily activities are The weather reports are prepared by
planned based on the weather predicted the Meteorological Department of the
for that day. There are daily reports of Government. This department collects
the weather on the television and data on temperature, wind, etc., and
radio and in the newspapers. But do you makes the weather prediction.
know what this weather really is?
In this chapter, we will study about Activity 7.1
the weather and climate. We will also
Cut out the weather reports of the last
see how different forms of life are
week from any newspaper. If you do not
adapted to the climate of their habitat.
get a newspaper at home borrow from
7.1 WEATHER your neighbours or friends and copy
In Fig. 7.1 a sample of weather report these reports in your notebook. You can
from a newspaper is given. also collect weather reports from a
We find that the daily weather report library. Paste all the cut-outs on a white
carries information about the sheet or on a chart paper.
temperature, humidity and rainfall Now record the information from the
during the past 24 hours. It also weather reports collected by you in
predicts the weather for the day. Table 7.1. The first row is just a sample.
Humidity, as you might know, is a Fill all the columns according to the data
measure of the moisture in air. in the chart that you have prepared.

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Table 7.1
Weather data of a week

Date Max. Min. Min. Max. Rainfall*
temp. (°C) temp. (°C) humidity (%) humidity(%) (mm)
23-08-06 36.2 27.8 54 82

*(Rainfall may not be recorded for all the days since it may not rain everyday. Leave
the space for rainfall blank if the data is not available.)

Rainfall is measured by an weather is too humid”, or “the weather
instrument called the rain gauge. It was warm last week”.
is basically a measuring cylinder with The weather is such a complex
a funnel on top to collect rainwater. phenomenon that it can vary over very
short periods of time. It can happen
Do all the seven days have the same
sometimes that it is sunny in the
maximum and minimum temperatures,
morning, but suddenly clouds appear
humidity and rainfall? The maximum
from nowhere and it starts raining
and minimum temperatures recorded
heavily. Or, a heavy rain may vanish in
may be the same for some of the days.
a matter of minutes and give way to
However, all the parameters are not the
bright sunshine. You must have had
same on any two days. Over a week there
several such experiences. Try to recall
may be considerable variation. The day-
any such experience and share it with
to-day condition of the atmosphere
your friends. Since weather is such a
at a place with respect to the
complex phenomenon, it is not easy to
temperature, humidity, rainfall, wind-
speed, etc., is called the weather at that predict.
place The temperature, humidity, and
place. Look at the graph given below which
other factors are called the elements of shows the maximum temperature
the weather. The weather of a place recorded during 03 August 2006 to 09
changes day after day and week after August 2006 at Shillong, Meghalaya
week. That is why we often say, “today’s (Fig. 7.2).

WEATHER, CLIMATE AND ADAPTATIONS OF ANIMALS TO CLIMATE 69

Date Maximum
temperature

03-08-06 26.0°C

04-08-06 23.5°C

05-08-06 25.0°C

06-08-06 22.0°C

07-08-06 25.5°C

08-08-06 23.3°C

09-08-06 24.4°C

Fig. 7.2 Graph showing the variation of maximum temperature during 03 to 09 August 2006

As it is clear from any weather report, that there are special thermometers for
the maximum and minimum this purpose, called maximum and
temperatures are recorded every day. Do minimum thermometers Can you
thermometers.
you know how these temperatures are guess when during the day we have the
recorded. In Chapter 4 you have learnt maximum temperature and when the
minimum?
The maximum temperature of the day
occurs generally in the afternoon while
I wonder why weather the minimum temperature occurs
changes so frequently! generally in the early morning. Can you
now understand why in summers we feel
What is the source of weather so miserable in the afternoon and
in the first place? comparatively comfortable early in the
morning?

All changes in the weather are caused by the sun The sun is a huge sphere of
sun.
hot gases at a very high temperature. The distance of the sun from us 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. If you live near the sea, you would have realised that the
weather at your place is different from that of a place in a desert, or near a mountain.

70 SCIENCE

What about the times of sunrise and of the time, then we say that the climate
sunset? You know that in winters it of that place is hot. If there is also heavy
becomes dark early and you do not get rainfall on most of the days in the same
much time to play. Are the days shorter place, then we can say that the climate
in winter than in summer? Try to find of that place is hot and wet.
it out yourself by completing the project In Table 7.2 and 7.3, we have given
given at the end of the chapter. the climatic condition at two places in
India. The mean temperature for a given
7.2 CLIMATE
month is found in two steps. First we
Meteorologists record the weather every find the average of the temperatures
day. The records of the weather have
recorded during the month. Second, we
been preserved for the past several
calculate the average of such average
decades. These help us to determine the temperatures over many years. That
weather pattern at a place. The average
gives the mean temperature. The two
weather pattern taken over a long
places are: Srinagar in Jammu and
time, say 25 years, is called the Kashmir, and Thiruvananthapuram in
climate of the place. If we find that
Kerala.
the temperature at a place is high most

Table 7.2 Srinagar (Jammu & Table 7.3 Thiruvananthapuram
Kashmir) (Kerala)
Information about climate Information about climate
Month Mean temperature Mean Month Mean temperature Mean
o
C total
o
C total
Daily Daily rainfall Daily Daily rainfall
minimum maximum (mm) minimum maximum (mm)
Jan -2.3 4.7 57 Jan 22.2 31.5 23
Feb -0.6 7.8 65 Feb 22.8 31.9 24
Mar 3.8 13.6 99 Mar 24.1 32.6 40
Apr 7.7 19.4 88 Apr 24.9 32.6 117
May 10.7 23.8 72 May 24.7 31.6 230
Jun 14.7 29.2 37 Jun 23.5 29.7 321
July 8.2 30.0 49 July 23.1 29.2 227
Aug 17.5 29.7 70 Aug 23.2 29.4 138
Sep 12.9 27.8 33 Sep 23.3 30.0 175
Oct 6.1 21.9 36 Oct 23.3 29.9 282
Nov 0.9 14.7 27 Nov 23.1 30.3 185
Dec -1.6 8.2 43 Dec 22.6 31.0 66
(Note: The numbers for the mean total rainfall have been rounded off)


By looking at Tables 7.2 and 7.3 we habitats. As examples of adaptation of
can easily see the difference in the animals to climatic conditions, we
climate of Jammu & Kashmir and discuss only animals living in polar
Kerala. We can see that Kerala is very regions and tropical rainforests.
hot and wet in comparison to Jammu As the name suggests, the polar
& Kashmir, which has a moderately hot regions are situated near the poles, i.e.,
and wet climate for a part of the year. north pole and south pole.
Similar data for the western region Some well-known countries that
of India, for example Rajasthan, will belong to the polar regions are Canada,
show that the temperature is high Greenland, Iceland, Norway, Sweden,
during most part of the year. But during Finland, Alaska in U.S.A. and Siberian
winter, which lasts only for a few region of Russia.
months, the temperature is quite low. Examples of some countries where
This region receives very little the tropical rainforests are found are
rainfall. This is the typical desert India, Malaysia, Indonesia, Brazil,
climate. It is hot and dry. The north- Republic of Congo, Kenya, Uganda, and
eastern India receives rain for a major Nigeria.
part of the year. Therefore, we can say
Activity 7.2
that the climate of the north-east is wet
wet.
Take an outline map of the world. Mark
7.3 CLIMATE AND ADAPTATION the polar regions in blue. Similarly,
Climate has a profound effect on all mark the tropical regions in red.
living organisms.
Animals are adapted to survive in the
(i) The polar regions
conditions in which they live. Animals The polar regions present an extreme
living in very cold and hot climate must climate. These regions are covered with
possess special features to protect snow and it is very cold for most part of
themselves against the extreme cold or the year. For six months the sun does
heat. Recall from Chapter 9 of your not set at the poles while for the other
Class VI science book the definition of six months the sun does not rise. In
adaptation. Features and habits that winters, the temperature can be as low
help animals to adapt to their as –37°C. Animals living there have
surroundings are a result of the process adapted to these severe conditions. Let
of evolution. us see how they are adapted by
In Chapter 9 you will learn about the considering the examples of polar bears
effect of weather and climate on soil. and penguins.
Here we study the effect of climate on Polar bears have white fur so that
animals only. In Class VI, you have read they are not easily visible in the snowy
about adaptations of animals to certain white background. It protects them from

72 SCIENCE

their predators. It also helps them in Another well-known animal living in
catching their prey. To protect them the polar regions is the penguin
from extreme cold, they have two thick (Fig. 7.4). It is also white and merges
layers of fur. They also have a layer of well with the white background. It also
fat under their skin. In fact, they are so has a thick skin and a lot of fat to protect
well-insulated that they have to move it from cold. You may have seen pictures
slowly and rest often to avoid getting of penguins huddled together. This they
overheated. do to keep warm. Recall how warm you
Physical activities on warm days feel when you are in a hall full of people.
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. We can understand the Fig. 7.4 Penguins huddled together
adaptations of polar bears with the help
of the flow chart shown in Fig. 7.3.

Fig. 7.3 Adaptations of polar bear


long, birds must remain warm to
survive. They migrate to warmer regions
when winter sets in. They come back
after the winter is over. You know
probably that India is one of the
destinations of many of these birds. You
Fig. 7.5 Feet of penguin must have seen or heard about the
Like polar bears, penguins are also good Siberian crane that comes from Siberia
swimmers. Their bodies are streamlined to places like Bharatpur in Rajasthan
and their feet have webs, making them and Sultanpur in Haryana, and some
good swimmers (Fig. 7.5).
Other animals living in the polar
regions are many types of fishes, musk
oxen, reindeers, foxes, seals, whales, Do fishes and butterflies
and birds. It is to be noted that while also migrate like birds?
fish can remain under cold water for

Fig. 7.6 Migratory birds
in their habitat/ Migratory
birds in flight

Did you know?
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.

74 SCIENCE

wetlands of north east and some other
parts of India (Fig. 7.6).
(ii) The tropical rainforests
The tropical region has generally a hot
climate because of its location around
Fig. 7.7 Red-eyed frog
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,
Fig. 7.8 A new world monkey
lions, tigers, elephants, leopards, lizards,
snakes, birds and insects. are such that they can easily hold on to
Let us read about the adaptations of the branches.
these animals to a hot, humid climate. As there is competition for food, some
The climatic conditions in rainforests animals are adapted to get food not
are highly suitable for supporting an easily reachable. A striking example is
enormous number and variety of that of the bird Toucan (Fig. 7.9), which
animals. possesses a long, large beak. This helps
Since the numbers are large, there a toucan to reach the fruits on branches
is intense competition for food and which are otherwise too weak to support
shelter. Many animals are adapted to its weight.
living on the trees. Red-eyed frog Many tropical animals have sensitive
(Fig. 7.7) has developed sticky pads on hearing, sharp eyesight, thick skin and
its feet to help it climb trees on which it a skin colour which helps them to
lives. To help them live on the trees, camouflage by blending with the
monkeys (Fig. 7.8) have long tails for surroundings. This is to protect them
grasping branches. Their hands and feet from predators. For example, big cats


(Fig. 7.11). 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
is able to handle the competition for food
Fig. 7.9 Toucan Fig. 7.10 Lion-tailed
macaque rather well. Large ears of the elephant
help it to hear even very soft sounds.
(lions and tigers) have thick skins and
They also help the elephant to keep cool
sensitive hearing.
in the hot and humid climate of the
The lion-tailed macaque (also called
rainforest.
Beard ape) lives in the rainforests of
Western Ghats (Fig. 7.10). 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 is able to get sufficient
food on the trees, it rarely comes down
on the ground.
Another well-known animal of Indian
tropical rainforest is the elephant Fig. 7.11 An Indian elephant

Keywords

Adaptation Maximum temperature Tropical rainforest
Climate Migration Tropical region
Elements of weather Minimum temperature Weather
Humidity Polar region

76 SCIENCE

What you have learnt
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.
The weather is generally not the same on any two days and week after
week.
The maximum temperature of the day occurs generally in the afternoon
while the minimum temperature occurs in the early morning.
The times of sunrise and sunset also change during the year.
All the changes in the weather are driven by the sun.
The average weather pattern taken over a long time, say 25 years, is
called the climate of the place.
The tropical and the polar regions are the two regions of the earth,
which have severe climatic conditions.
Animals are adapted to the conditions in which they live.
The polar regions are very cold throughout the year. The sun does not
set for six months in a year and in the other six months it does not rise.
Animals in the polar region are adapted to the extremely cold climate by
having some special characteristics such as white fur, strong sense of
smell, a layer of fat under the skin, wide and large paws for swimming
and walking, etc.
Migration is another means to escape the harsh, cold conditions.
Because of the hospitable climatic conditions huge populations of plants
and animals are found in the tropical rainforests.
Animals in the tropical rainforests are adapted such that they eat
different kinds of food to overcome the competition for food and shelter.
Some adaptations of animals living in the tropical rainforests include
living on the trees, development of strong tails, long and large beaks,
bright colours, sharp patterns, loud voice, diet of fruits, sensitive hearing,
sharp eyesight, thick skin, ability to camouflage in order to protect
themselves from predators, etc.

Exercises
1. Name the elements that determine the weather of a place.
2. When are the maximum and minimum temperature likely to occur
during the day?
3. Fill in the blanks:
(i) The average weather taken over a long time is called ___________.


(ii) A place receives very little rainfall and the temperature is
high throughout the year, the climate of that place will be
___________ and ___________ .
(iii) The two regions of the earth with extreme climatic conditions are
___________ and __________.
4. Indicate the type of climate of the following areas:
(a) Jammu and Kashmir: _________________________________

(b) Kerala: ____________________________________________
(c) Rajasthan: __________________________________________
(d) North-east India: _____________________________________
5. Which of the two changes frequently, weather or climate?
6. Following are some of the characteristics of animals:
(i) Diets heavy on fruits (ii) White fur
(iii) Need to migrate (iv) Loud voice
(v) Sticky pads on feet (vi) Layer of fat under skin
(vii) Wide and large paws (viii) Bright colours
(ix) Strong tails (x) Long and large beak
For each characteristic indicate whether it is adaptation for tropical
rainforests or polar regions. Do you think that some of these
characteristics can be adapted for both regions?
7. The tropical rainforest has a large population of animals. Explain why
it is so.
8. Explain, with examples, why we find animals of certain kind living in
particular climatic conditions.
9. How do elephant living in the tropical rainforest adapt itself.
Choose the correct option which answers the following question:
10. A carnivore with stripes on its body moves very fast while catching its
prey. It is likely to be found in
(i) polar regions (ii) deserts
(iii) oceans (iv) tropical rainforests
11. Which features adapt polar bears to live in extremely cold climate?
(i) A white fur, fat below skin, keen sense of smell.
(ii) Thin skin, large eyes, a white fur.
(iii) A long tail, strong claws, white large paws.
(iv) White body, paws for swimming, gills for respiration.

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12. Which option best describes a tropical region?
(i) hot and humid
(ii) moderate temperature, heavy rainfall
(iii) cold and humid
(iv) hot and dry

Extended Learning — Projects and Activities
1. Collect weather reports of seven successive days in the winter months
(preferably December). Collect similar reports for the summer months
(preferably June). Now prepare a table for sunrise and sunset times as
shown:
Table
June December
Date Sunrise Sunset Date Sunrise Sunset

Try to answer the following questions:
(i) Is there any difference in the time of sunrise during summer and
winter?
(ii) When do you find that the sun rises earlier?
(iii) Do you also find any difference in the time of sunset during the
month of June and December?
(iv) When are the days longer?
(v) When are the nights longer?
(vi) Why are the days sometimes longer and sometimes shorter?
(vii) Plot the length of the day against the days chosen in June and
December.
(Instructions for plotting graphs are given in Chapter 13.)
2. Collect information about the Indian Meteorological Department. If
possible visit its website: http//www.imd.gov.in.
Write a breif report about the things this department does.

Did you know?
Rainforests cover about 6% of the earth’s surface, but they have more
than half of the animal life and about two-thirds of the flowering plants
of the planet. However, much of this life is still unknown to us.


7 weather, climate and animal adaptations to climate

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