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The Migration of Birds
In the Qur’an, Allah calls us to give attention to birds with His verse
"Have they not looked at the birds above them, with
wings outspread and folded back? Nothing holds them up but the All-Merciful.
He sees all things." (Surat al-Mulk: 19) In this part, we will
particularly review migratory birds; we will describe what perfect balances
they establish travelling in the skies, and the systems their bodies are
endowed with, and focus on the wonder of Allah’s upholding them "in the
sky".
HOW DO BIRDS DETERMINE THE TIME OF MIGRATION?
Why and how birds started to migrate and what made them take the "decision
of migration" have long been topics of interest. Some scientists hold the
reason of migration to be seasonal changes while some others believe the
reason to be the search for food. What deserves consideration is how these
animals, having no protection, technical outfit, and security but only their
bodies, can make these very long-distance flights. Migration requires some
special skills like orientation, food storage, and the ability to fly for
long periods. It is impossible for an animal not possessing these characteristics
to transform into a migratory animal.
One of the experiments made to address this issue is as follows: garden nightingales
were subjected to experiments in a lab where internal conditions such
as temperature and light could be varied. Internal conditions were arranged
differently from external conditions. For instance, if it was winter outside,
a spring climate was created in the laboratory and the birds arranged
their bodies in accordance with that. The birds stored fat for fuel, just
as they do when time for migration approaches. Although birds organised
themselves according to the artificial season, and prepared themselves
as if they were going to migrate, they did not set out to migrate before
it was time. They observed the season outside. This was evidence that
birds do not take the decision to start migration according to seasonal
conditions.
How, then, do birds determine the time for migration? Scientists have
still not found an answer to this question. They believe that living things
have "body clocks" that help them to know the time in a closed environment
and to differentiate seasonal changes. However, the answer that "birds
have body clocks with which they understand the time of migration" is
an unscientific answer. What kind of clock is it, which organ of the body
does it work with, and how did it come into being? What would happen if
this clock were out of order or stayed behind?
Considering that the same system holds true not only for a single migratory
bird, but for all migratory animals, more importance must be attributed
to these questions.
 As
is well known, migratory birds do not start migration from the same place,
as none of them are found at the same place when the time for migration
arrives. Most species first meet at a particular location and then migrate
together. How do they arrange such timing? How are these "body-clocks",
that birds allegedly have, so harmonious? Is it possible that such a systematic
order could come into being spontaneously?
It is impossible for a planned action to take place spontaneously. In
addition, neither in birds nor in other migratory animals is there a clock
of any kind. All migratory living things do this every year at times determined
by them, but they do not do it by observing a body clock. What some people
call a body clock is Allah’s control over these living beings. Migratory
animals follow Allah’s orders just like everything in the universe.
USAGE OF ENERGY
  Birds
consume great energy in flight. For this reason, they need more fuel than
all sea-dwelling and land-dwelling animals. For instance, in order to fly
the 3,000 km distance between Hawaii and Alaska, a humming bird, weighing
a few grams, has to beat its wings 2.5 million times. Despite this,
it can remain in the air for as long as 36 hours. Its average speed during
this trip is approximately 80 km per hour. During a flight as arduous as
that, the quantity of acid in the bird’s blood increases excessively and
the bird faces the danger of fainting because of its rising body temperature.
Some birds deal with this danger by landing. How, then, can those that migrate
over enormous oceans save themselves? Ornithologists have observed that
under such circumstances, birds spread their wings as wide as possible and
so cool down by resting in this manner.
The metabolisms of migratory birds are strong enough to put up with this
task. For instance, the metabolic activity in the body of a humming bird,
the smallest bird of passage, is 20 times more than that in an elephant.
The body temperature of the bird rises to 62º C.
FLIGHT TECHNIQUES
  In
addition to having been created ready to endure such arduous flights, birds
are also gifted with skills that enable to them to make use of favourable
winds.
For instance, storks go up as high as 2,000 m with rising warm air currents,
and then glide along swiftly to the next warm air current without beating
their wings.
Another flight technique used by bird flocks is the "V" type flight formation.
In this technique, big strong birds at the front function as shields against
counter air currents and lead the way for the weaker. Aeronautical engineer
Dietrich Hummel has proved that with such organisation, a saving of 23%
is achieved in the flock in general.
FLIGHT AT HIGH ALTITUDE
When the bird ascending in the warm air current reaches the top,
it glides down swiftly. This helps the bird save a great amount
of energy both in ascent and descent. |
Some migrating birds fly at very high altitudes. For instance geese can
fly at an altitude of 8,000 m. This is an incredible altitude considering
the fact that even at 5,000 metres the atmosphere is 63% less dense than
at sea level. Flying at such a height where the atmosphere is so thin, the
bird has to beat its wings faster and hence has to find more oxygen.
However, the lungs of these animals are created in such a way as to take maximum
benefit from the oxygen available at these heights. Their lungs, which
function differently from those of mammals, help them obtain higher level
of energy from scarce air.
 The
illustration on the left shows the twelve factors beneficial to birds
while flying:
1. The sun,
2. Sense of timing,
3. Location of the stars,
4. Ultraviolet rays,
5. Polarised light,
6. Sounds of very low frequency,
7. Sounds such as of waves and thunder coming from very far away,
8. The magnetic field of the earth,
9. Gravity,
10. Meteorological assessment,
11. Favourable winds,
12. Characteristics of the ground below. |
A PERFECT SENSE OF HEARING
During migration, birds also take atmospheric phenomena into consideration.
For instance, they change direction to avoid a coming storm. Melvin L. Kreithen,
an ornithologist who made research into birds’ sense of hearing, observed
that some birds can hear sounds of extremely small frequencies, which diffuse
to great distances in the atmosphere. A migratory bird can therefore hear
a storm breaking out over a far away mountain or thunder over an ocean hundreds
of kilometres ahead. Besides, it is a known fact that birds are careful
to set their routes of migration away from regions where atmospheric conditions
are risky.
 
PERCEPTION OF DIRECTION
How do birds find their direction without the help of a map, a compass or
some similar direction finder during their thousands of kilometres long
flights?
The first theory put forward regarding this question was that birds memorise
the characteristics of the ground beneath them and thus reach their destination
without being confused. Yet, experiments have shown that this theory is
incorrect.
In an experiment on pigeons addressing this subject, opaque lenses were
used to blur the vision of pigeons. Thus, they were prevented from navigating
by landmarks on the ground, yet the pigeons could still find their way
even if left some kilometres away from their flocks.
Subsequent research has shown that the magnetic field of the earth seems
to act on bird species. Various studies have shown that birds have seemingly
advanced, magnetic receptor systems enabling them to find their way by
making use of the magnetic field of the earth. This system helps birds
determine their direction by sensing the change in the magnetic field
of the earth during their migrations. Experiments reveal that migratory
birds can even perceive a 2% variation in the magnetic field of the earth.
Some think that they can explain the subject away by saying that birds
have a sort of compass in their bodies. The main question, however, lies
just here.
The question is: how do the birds come to be equipped with a "natural
compass"? We are aware that the compass is an "invention" and a work of
human intelligence. So how does a compass - an apparatus produced by man
with his collected knowledge - come to exist in the bodies of birds? Is
it likely that some years ago, a bird species, while finding direction,
thought about making use of the magnetic field of the earth and invented
a magnetic receptor for its own body? Alternatively, was a bird species,
years ago, equipped with such a mechanism by "coincidence"? Definitely
not....
Neither the bird itself nor a coincidence can add an extremely advanced
compass to the body. The bird’s body structure, lungs, wings, digestive
system and its ability to find direction are the examples of the perfect
creation of Allah:
"He is Allah - the Creator, the Maker, the Giver
of Form. To Him belong the Most Beautiful Names. Everything in the heavens
and earth glorifies Him. He is the Almighty, the All-Wise." (Surat al-Hashr:
24)
"Do you not see that everyone in the heavens
and earth glorifies Allah, as do the birds with their outspread
wings? Each one knows its prayer and glorification. Allah knows
what they do."
(Surat an-Nur: 41)
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AMAZING JOURNEY OF MONARCH
BUTTERFLIES
 The
migration story of Monarch butterflies, which live in southeast Canada,
is more complex than that of the birds.
Monarch butterflies normally live for only 5-6 weeks after they develop
from caterpillar. Four generations of Monarch butterflies live within
a year. Three of these four generations live in spring and summertime.
With the coming of autumn, the situation changes. Migration starts in
autumn and the generation that migrates, lives much longer than the other
generations that lived in the same year. The Monarchs that migrate are
the fourth generation in the year.
Interestingly enough, the migration starts exactly on the night of the
autumn equinox. The butterflies that migrate to the south live six months
longer than the previous three generations. They need to live exactly
this long to complete their journey and return.
The butterflies that go down to the south do not disperse after they
pass across the Tropic of Cancer and leave the cold weather behind. After
migrating over half of the American continent, millions of butterflies
settle down in the middle of Mexico. Here the ridges of volcanic mountains
are covered with a great variety of flora. Located at a height of 3,000
metres, this place is warm enough for the subsistence of the butterflies.
For a period of four months, from December to March, they eat nothing.
As the fat stored in their bodies nourishes them, they only drink water.
 Flowers
that bloom in the spring are quite important for the Monarchs. After a
four-month fast, for the first time, in the spring they give themselves
a nectar feast. They now have stored enough energy to return to North
America. This generation, which lives a two-month life span extended to
eight months, is no different from the three earlier generations in other
respects. They mate at the end of March before setting out to their journey.
On the equinox, the colony starts flying back to the north. Soon after
they complete their journey and arrive in Canada, they die. However, before
they die, they give birth to a new generation, which is necessary for
the perpetuation of their species.
 The
newly born generation is the first generation of the year and lives about
one and a half months long. Then comes the second and third generations.
When it comes to the fourth generation, migration starts over again. This
generation will live six months longer than the others will, and the chain
will continue in the same way.
This interesting system provokes many questions: how is that the fourth
of every four generations lives six months longer? How does this long-lived
generation always coincide with winter and has done so for thousands of
years? How do these butterflies always start migrating at the equinox,
and how do they attune themselves so sensitively, or are they using a
calendar?
No doubt, there are no answers to these questions through "evolution"
or other variants on that theory. The butterflies must have borne these
interesting characteristics from the time they came into existence. If
the first fourth generation of Monarchs on earth did not have the characteristic
to live long, then all the butterflies would die within that winter and
these animals would become extinct.
Monarchs must have borne this extraordinary characteristic from the time they were created. "Coincidences" unquestionably do not have such a faculty as could arrange the generations of the animal according to migration. On the other hand, it is also unlikely that butterflies decided to make their fourth generations live longer and arranged their metabolisms, DNA, and genes accordingly.
Obviously, the Monarchs were created possessing such features.
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