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".
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.
How do the birds determine the time of migration?
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?
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.
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
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
biryolculuđu boyunca 2.5 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.
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 high altitude
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.
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.
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
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
8. The magnetic field of the earth,
10. Meteorological assessment,
11. Favourable winds,
12. Characteristics of the ground below.
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.
A perfect sense of hearing
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?
Perception of direction
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)
migration story of Monarch butterflies, which live in southeast Canada,
is more complex than that of the birds.
AMAZING JOURNEY OF MONARCH
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
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
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.
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
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