Flawless Flying Machines: Birds
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)
Because they believe that the birds must have somehow evolved, evolutionists
assert that birds are descendants of reptiles. However, the progressive
model of evolution cannot explain any of the body mechanisms of birds,
which have a completely different structure from land-dwelling animals.
First, the primary feature of birds, i.e. wings, is a great obstacle for
the theory of evolution to explain. One of the Turkish evolutionists,
Engin Korur, makes the following confession in reference to the impossibility
of the evolution of wings:
The common trait of eyes and the wings is that they can
only function if they are fully developed. In other words, a halfway-developed
eye cannot see and a bird with half-formed wings cannot fly. How these organs
came into being is one of those mysteries of nature that has still to be
The question of how the flawless structure of wings might have been formed
through a series of consecutive random mutations remains completely unanswered.
The process in which the front leg of a reptile could transform into a
flawless wing seems to be as inexplicable as ever.
Furthermore, the existence of wings is not the only prerequisite for
a land creature to become a bird. Land-dwelling animals totally lack a
number of mechanisms that are used by birds in flying. For example, the
bones of birds are considerably lighter than those of land-dwelling animals.
Their lungs are of a different structure and function as well as are their
skeletal and muscular structures. Their circulatory systems are much more
specialised than those of land animals. All of these mechanisms could
not possibly come into existence over time through an "accumulative process".
Assertions of the transformation of land-dwelling animals into birds are,
therefore, only nonsensical claims.
Structure of Bird Feathers
The theory of evolution, which claims that birds are descendants of
reptiles, is not able to explain the colossal differences between these
two classes of beings. Birds display properties distinct from reptiles
in having a skeletal structure composed of hollow, extremely lightweight
bones, and a unique respiratory system and in being warm-blooded creatures.
Another structure unique to birds, which places an unbridgeable gap between
birds and reptiles, is the feather.
Feathers are the most important of the interesting aesthetical aspects of
birds. The phrase "light as a feather" depicts the perfection in the intricate
structure of a feather.
Feathers are constructed of a protein substance called keratin. Keratin
is a hard and durable material that is formed by the old cells that migrate
away from the nutrient and oxygen sources in the deeper layers of the
skin and die in order to give way to new cells.
The design in bird feathers is so complex that the process
of evolution simply cannot explain it. Scientist Alan Feduccia says feathers
"have an almost magical structural complexity" which "allows a mechanical
aerodynamic refinement never achieved by other means".14
Although he is an evolutionist, Feduccia also admits that "feathers
are a near-perfect adaptation for flight" because they are lightweight,
strong, aedodynamically shaped, and have an intricate structure of barbs
The design of feathers also compelled Charles Darwin ponder them. Moreover,
the perfect aesthetics of the peacock's feathers had made him "sick" (his
own words). In a letter he wrote to Asa Gray on April 3, 1860, he said
"I remember well the time when the thought of the eye made me cold all
over, but I have got over this stage of complaint..." And then continued:
... and now trifling particulars of structure often make
me very uncomfortable. The sight of a feather in a peacock's tail, whenever
I gaze at it, makes me sick!16
Small Barbs and Hooklets
One encounters an incredible design if the feather of a bird is examined
under the microscope. As we all know, there is a shaft that runs up the
centre of the feather. Hundreds of small barbs grow on either side of
this shaft. Barbs of varying softness and size give the bird its aerodynamic
nature. Furthermore, each barb has thousands of even smaller strands attached
to them called barbules, which cannot be observed with the naked eye.
These barbules are locked together with hooklike hamuli. The barbules
hold on to one another like a zip with the help of these hooklets. For
example, just one crane feather has about 650 barbs on each side of the
shaft. About 600 barbules branch off each of the barbs. Each one of these
barbules are locked together with 390 hooklets. The hooks latch together
as do the teeth on both sides of a zip. These barbules interlock so tightly
that even smoke blown at the feather cannot penetrate through it. If the
hooklets come apart for any reason, the bird can easily restore the feathers
to their original form by either shaking itself or by straightening its
feathers out with its beak.
Feathers spring from a hollow cylindrical structure
of the skin.
A chick that is 2-3 hours old primarily has feathers for warmth.
In order to survive, birds have to keep their feathers clean, well-groomed
and always ready for flight. They use an oil-gland located at the base
of their tails for the maintenance of their feathers. They clean and polish
their feathers by means of this oil, which also provides water proofing
when they are swimming, diving or walking and flying in rain.
In addition, in cold weather the feathers prevent the
body temperature of birds from falling. The feathers are pressed closer
to the body in hot weather in order to keep it cool.17
Types of Feather
Feathers take on different functions depending on where
on the body they are located. The feathers on a bird's body have different
properties from those on the wings or tail. The full-feathered tail functions
to steer and brake. On the other hand, wing feathers have a distinct structure
that enables the surface area to expand during beating in order to increase
forces of up-lift. When the wing is flapped downward, the feathers come
closer together, preventing the through passage of air. When the wing is
in an upward movement the feathers open up, to give way to the passage of
air.18 Birds shed their feathers
during certain periods in order to maintain their abilities to fly. Worn
or damaged large feathers are renewed immediately.
ARTISTRY OF THE WINGS
This serial motion depicts various
phases in a sparrow's flight: take-off, short flight and landing.
Feathers on the head, body and wings protect the birds from moisture
and cold. They also help in the bird's soaring in the air. Feathers
on the side cover the delicate skin that helps regulate body temperature.
Due to the curvature of the wing, air pressure
on the upper surface is weaker than on the under surface, which
in turn lifts the bird into the air (bottom left). If the wing
is curved, further airflow at the top increases the pressure creating
a downward force. This way the bird stalls
The wing of a goatsucker
Yellow lines indicate the curvature of the
The wing of a falcon
(left) There are primarily three forms of flight
(from top to bottom): Serial flight, V-formation and group flight.
(right) The majority of birds can fly, but not all move the same
way. Some birds have such advanced flying skills that they can fly
very close to the earth. The shape of the wings depends on the species.
FEATURES OF THE FLYING MACHINES
A close examination of birds reveals that they are designed specifically
for flying. The body has been created with air-sacs and hollow bones in
order to reduce body mass and overall weight. The fluid nature of their
wastes ensures that excess water in the body is disposed of. Feathers
are extremely light structures in comparison to their volume.
Let us examine these special structures of birds one by one:
1- The skeleton
The strength of a bird's skeleton is more than adequate even though the
bones are hollow. For example, a hawfinch 7 inches long (18 cm) exerts
about 151 lbs. (68.5 kg) pressure in order to crack open an olive seed.
Better "organised" than land animals, the shoulder, hip and chest bones
of birds are fused together. This design improves the strength of the
bird's structure. Another feature of the skeleton of birds, as mentioned
previously, is that it is lighter than in all other land-dwelling animals.
For instance, the skeleton of the dove weighs only about 4.4% of its total
body weight. The bones of the frigate bird weigh 118 gr, which is less
than the total weight of its feathers.
Bird bones are extremely light but sturdy,
largely because they are hollow. There is air inside the cavities
where supporting bars stiffen the bones. These hollow bones are
the main inspirations for the design of modern aeroplane wings.
2- Respiratory System
The respiratory system of land animals and birds operate on completely different
principles, primarily because birds need oxygen in much greater quantities
than do land animals. For example, a certain bird could require up to twenty
times the amount of oxygen necessary for humans. Therefore, the lungs of
land animals cannot provide oxygen in the quantities required by birds.
This is why the lungs of birds are created upon a much different design.
SPECIAL LUNGS OF BIRDS
Birds have a ery different anatomy from their alleged ancestors,
the reptiles. Bird lungs operate in a completely different fashion
from those of land animals. Land animals inhale and exhale air through
the same windpipe. In birds, however, the air enters and exits through
opposite ends. A special "design" such as this has been created
to provide for the high volumes of air needed during flight. Evolution
of such a structure from that of reptiles is not possible.
In land animals, air flow is bidirectional: air travels through a network
of channels, and stops at the small air sacs. Oxygen-carbon dioxide exchange
takes place here. Used air follows a reverse course in leaving the lung
and is discharged through the windpipe.
On contrary, in birds, air flow is unidirectional. New air comes in one
end, and the used air goes out the other end. This provides an uninterrupted
supply of oxygen for birds, which satisfies their need for high levels
of energy. Michael Denton, an Australian biochemist and a well-known critic
of Darwinism, explains the avian lung in this way:
In the case of birds, the major bronchi break down into
tiny tubes which permeate the lung tissue. These so-called parabronchi eventually
join up together again, forming a true circulatory system so that air flows
in one direction through the lungs
. Although air sacs occur in certain
reptilian groups, the structure of the lung in birds and the overall functioning
of the respiratory system is quite unique. No lung in any other vertebrate
species is known which in any way approaches the avian system. Moreover,
it is identical in all essential details in birds
In his book Evolution: A Theory in Crisis, Michael Denton also points
out to the impossibility of formation of such a perfect system through
Just how such an utterly different respiratory system
could have evolved gradually from the standard vertebrate design is fantastically
difficult to envisage, especially bearing in mind that the maintenance of
respiratory function is absolutely vital to the life of an organism to the
extent that the slightest malfunction leads to death within minutes. Just
as the feather cannot function as an organ of flight until the hooks and
barbules are coadapted to fit together perfectly, so the avian lung cannot
function as an organ of respiration until the parabronchi system which permeates
it and the air sac system which guarantees the parabronchi their air supply
are both highly developed and able to function together in a perfectly integrated
||Unidirectional airflow in the bird's
lungs is facilitated by a system of air-sacs. These sacs collect air
and then pump it regularly into the lung. In this way, there is always
fresh air in the lungs. A complex respiratory system such as this
has been created to satisfy birds' needs for high quantities of oxygen.
In short, the transition from terrestrial lung to avian lung is impossible
due to the fact that the lung that would be in a transitional developmental
stage would have no functionality. No creature without lungs can live
for even a few minutes. Therefore, the creature simply would not have
millions of years to wait for random mutations to save its life.
The unique structure of the avian lung demonstrates the presence of a
perfect design that supplies the high levels of oxygen required for flight.
It only takes a little bit of a common sense to see that the unparalleled
anatomy of birds is not an arbitrary result of unconscious mutations.
It is clear that the lungs of a bird are another of the countless evidences
that all creatures have been created by Allah.
3-The System of Balance
Allah has created birds without flaw just as He has the rest of the creation.
This fact is manifest in every detail. The bodies of birds have been created
to a special design that removes any possible imbalance in flight. The
bird's head has been deliberately created light in weight so that the
animal does not lean forward during flight: on average, a bird's head
weight is about 1% of its body weight.
The aerodynamic structure of the feathers is another property of the
system of balance in birds. The feathers, especially in the wing and tail,
provide a very effective system of balance for the bird.
These features ensure that a falcon maintains absolute balance while
diving for its prey at a speed of 240 mph (384 km/h).
4- The Power and Energy Problem
Every process in the form of a sequence of events, i.e. in biology, chemistry
or physics, conforms to the "Principle of the Conservation of Energy".
In short, one can summarise this as "it takes a certain amount of energy
to get a certain work done".
A significant example of this conservation can be observed in flight
of birds. Migrating birds have to store enough energy to take them through
their trip. On the other hand, another necessity in flight is being as
light as possible. No matter what the results, extra weight has to be
done away with. In the meantime, the fuel has also to be as efficient
as possible. In other words, while the weight of fuel has to be at a minimum,
the energy output from it has to be at a maximum. All of these problems
have been solved for birds.
The first step is to determine the optimum speed for flight. If the bird
is to fly very slowly, then a lot of energy has to be spent to remain
aloft in the air. If the bird is to fly very fast, then fuel will be spent
in overcoming air resistance. It is therefore obvious that an ideal speed
has to be maintained in order to spend the least amount of fuel. Depending
on the aerodynamic structure of the skeleton and wings, a different speed
is ideal for each kind of bird.
Let us examine this energy problem as it relates to the Pacific golden
plover (Pluvialis dominica fulva): this bird migrates from Alaska to Hawaii
to spend its winters there. There are no islands on its route. Therefore,
it has no possibility for rest. The flight is 2500 miles (4000 km) from
start to finish and this roughly means 250,000 wing beats without break.
The trip takes more than 88 hours.
The bird weighs 7 ounces (200g) at the start of the journey, 2,5 ounces
(70g) of which is fat to be used as fuel. However, scientists, after calculating
the amount of energy the bird needs for an hour of flight, determined
that the bird needed 3 ounces (82g) of fuel for this flight. That is,
there is a shortage of 0.4 ounce (12g) of fuel and the bird would have
to run out of energy hundreds of miles before reaching Hawaii.
In spite of these calculations, the golden rain birds unfailingly reach
Hawaii every year. What could the secret of these creatures be?
The Creator of these birds, Allah, inspires them with
a method to make their flight easy and efficient. The birds do not fly haphazardly
but in a flock. They follow a certain order and form a "V" shape in the
air. This V formation reduces the air resistance that they encounter. This
flight formation is so efficient that they save about 23% of their energy.
This is how they still have 0.2 ounces (6-7g) of fat when they land. The
extra fat is not a miscalculation but a cushion to be used in case of encountering
reverse air currents.21
This extraordinary situation brings the following questions to mind:
How could the bird know how much fat is needed?
How could the bird manage to acquire all this fat before flight?
How could it calculate the distance and the amount of fuel it needs to
How could the bird know that conditions in Hawaii are better than Alaska?
It is impossible for birds to reach this knowledge, to make these calculations,
or to make group flights according to these calculations. This is an indication
that the birds are "inspired" and directed by a superior power. Likewise
Qur'an draws attention to "birds lined up in flight" and informs us about
a consciousness that is inspired in these creatures by Allah:
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)
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)
5- Digestion System
Flight requires a great deal of power. For this reason birds have the
largest muscle-tissue/body-mass ratio of all creatures. Their metabolism
is also in tune with high levels of muscle power. On average, a creature's
metabolism doubles as the body temperature increases by 500F (100C). The
sparrow's 1080F (420C) body temperature and a fieldfare's 109.40F (43.50C)body
temperature indicate how quickly their metabolism functions. Such a high
body temperature, which would kill a land creature, is vitally important
for a bird's survival by increasing energy consumption and, therefore,
Due to their need for a lot of energy, birds also have a body that digests
the food they eat in an optimum fashion. Birds' digestive systems enable
them to make the best use of the food they eat. For example, a baby stork
puts on 2.2 lbs (1 kg) body mass for every 6.6 lbs (3 kg) food. In land
animals with similar food choices, this ratio is about 2.2 lbs (1 kg)
to 22 lbs. (10 kg). The circulatory system of birds has also been created
in harmony with their high energy requirements. While a human's heart
beats 78 times a minute, this rate is 460 for a sparrow and 615 for a
humming bird. Similarly, blood circulation in birds is very fast. The
oxygen that supplies all of these fast working systems is provided by
special avian lungs.
Birds also use their energy very efficiently. They demonstrate significantly
higher efficiency in energy consumption than do land animals. For instance,
a migrating swallow burns four kilocalories per mile (2.5 per kilometre)
whereas a small land animal would burn 41 kilocalories.
Birds prefer to travel in flocks
on long trips. The "V" formation of the flock enables each individual
bird to save about 23% energy.
Mutation cannot explain the differences between birds and land animals.
Even if we assume one of these features to occur through random mutation,
which is not a possibility, a single feature by itself does not make any
sense. The formation of a high energy-producing metabolism has no meaning
without specialised avian lungs. Moreover, this would cause the animal
to choke from insufficient oxygen intake. If the respiratory system were
to mutate before the other systems then the creature would inhale more
oxygen than it needs, and would be harmed just the same. Another impossibility
relates to the skeletal structure: even if the bird somehow obtained the
avian lungs and metabolic adaptations it still could not fly. No matter
how powerful, no land creature can take off from the ground due to its
heavy and relatively segmented skeletal structure. The formation of wings
also requires a distinct and flawless "design".
All of these facts take us to one result: it is simply impossible to
explain the origin of birds through accidental growth or a theory of evolution.
Thousands of different species of birds have been created with all their
current physical features in "a moment". In other words, Allah has created
The sparrow's heart beats 460 times per minute.
Its body temperature is 1080F (420C). Such a high body temperature,
which would mean certain death for a land creature, is vitally important
for a bird's survival. The high level of energy birds require for
flight is generated by this rapid metabolism.
PERFECT FLIGHT TECHNIQUES
From albatrosses to vultures, all birds have been created equipped with
flying techniques that make use of winds.
flying consumes a lot of energy, birds have been created with powerful breast
muscles, large hearts and light skeletons. The evidence of superior creation
in birds does not end with their bodies. Many birds have been inspired to
use methods that decrease the energy required.
The kestrel is a wild bird that is well-known in Europe,
Asia and Africa. It has a special ability: it can maintain its head in a
perfectly still position in the air by facing the wind. Though its body
may sway in the wind, its head remains motionless, which increases the excellence
of its vision in spite of all the motion. A gyroscope, which is used to
stabilise the weaponry of battleships at sea, works very similarly. This
is why scientists usually label the bird's head "a gyro-stabilised head".22
Birds regulate their hunting schedules for optimum efficiency.
Kestrels like to feed on rats. Rats typically live underground and surface
every two hours to feed. Kestrels' feeding coincides with the rats'. They
hunt during the day but eat their kill at night. Therefore, during the day,
they fly on empty stomachs with less weight. This method cuts down the energy
required. It has been calculated that the bird saves about 7% energy this
Soaring in the Wind
Birds further reduce the energy consumed by utilising winds. They soar
by increasing airflow on their wings and they can remain "suspended" in
sufficiently powerful air currents. Up-drafts are an added advantage to
Making use of air currents in order to save energy in flight is called
"soaring". The kestrel is one of the birds with this capability. The ability
to soar is a sign of birds' superiority in the air.
Soaring has two major benefits. Firstly, it conserves
energy needed to stay in the air while searching for food or defending the
feeding ground. Secondly, it enables the bird to significantly increase
its flight distances. A seagull can save up to 70% of its energy while soaring.24
Energy from Air Currents
use air streams in different ways: A kestrel gliding down a hillside or
a seagull diving along coastal cliffs make use of airstreams, and this is
called "slope soaring".
When a strong wind passes over a hilltop, it forms waves of motionless
air. Birds can soar on these waves as well. The gannet and many other
seabirds make use of these motionless waves created by islands. Sometimes
they use the currents generated by smaller obstacles such as ships, over
which seagulls soar.
Fronts generally create the currents providing uplift for birds.
Fronts are interfaces between air masses of different temperatures or
densities. The soaring of birds on these interfaces is referred to as
"gust gliding". These fronts, which are especially formed at coasts by
air currents coming from the sea, have been discovered by means of radar,
through the observation of sea birds in flocks gliding in them. Two other
kinds of soaring are known as thermal soaring and dynamic soaring.
Thermal soaring is a phenomenon observed especially in warm inland areas
of the globe. As the sun heats the ground, the ground in turn heats the
air above it. As the air gets warmer, it gets lighter and starts to rise.
This event can also be observed in dust storms or other wind whirls.
The Soaring Technique of Vultures
Vultures utilise a special method in order to scan the earth below from
an appropriate height riding rising columns of warm air, called the thermals.
They can continuously make use of different thermals to sustain their soaring
over very large areas for very long times.
At dawn, airwaves start rising. First, smaller vultures take off, riding
weaker currents. As currents become stronger, larger birds take off as
well. Vultures almost float upward in these ascending currents. The fastest
rising air is located in the middle of the current. They fly in tight
circles in order to balance uplift with gravitational forces. When they
want to ascend, they draw closer to the centre of the currents.
Other hunting birds use thermals as well. Storks make use of these warm
air currents, especially when migrating. The white stork lives in central
Europe and migrates to Africa for winters on a journey of about 4350 miles
(7000 kilometres). If they were to fly solely by flapping their wings,
they would have to rest at least four times. Instead, the white storks
complete their flights in three weeks by utilising warm air currents for
up to 6-7 hours a day, which translates into big energy savings.
Since the waters warm up much later than the land, warm air currents are
not formed over the seas, which is why birds that migrate over long distances
do not choose to travel over water. Storks and other wild birds migrating
from Europe to Africa choose to travel either over the Balkans and the Bosphorus,
or over the Iberian Peninsula over the Gibraltar.
The albatross, gannets, seagulls and other sea birds, on the other hand,
use the air currents that are created by high waves. These birds take
advantage of the uplift of air directed upwards on the tips of waves.
While soaring on the air currents, the albatross frequently turns and
heads into the wind and swiftly rises higher. After ascending 30-45 feet
(10-15 metres) into the air, it changes direction again and continues
soaring. The bird gains energy from changes in wind directions. The air
currents lose speed when they hit the surface of the sea. This is why
the albatross encounters stronger currents at higher altitudes. After
attaining adequate speed, it returns to gliding close to the surface of
the sea. Many other birds such as the shearwater use similar techniques
while soaring on the sea.
Vultures can reach their food
before their rivals, the hyenas, due to their flight techniques.
In the figure above, the griffon vulture feeding on a carcass catches
the attention of a lappet-faced vulture and a hyena. However, even
the hyena's highest speed of 25 mph (40 km/h) is not enough to reach
the carcass in time. The hyena can reach a carcass 2.2 miles away
(3.5 kilometres) in 4.25 minutes whereas the lappet-faced vulture
reaches the carcass in three minutes at a speed of 44 mph (70 km/h).
albatross with a wingspan of 10 feet (3 metres) is one of the world's
largest birds. Such a large body requires a lot of energy for flight.
However, the albatross can fly long distances without flapping its
wings by using the dynamic soaring method. This technique saves this
creature tremendous amounts of energy.
|Wild geese climb up to 5 miles (8 kilometres). However, at about
3.1 miles (5 kilometres), the atmosphere is 65% less dense than at
sea level. A bird flying at this height has to flap its wings much
faster, which would require much more oxygen. In sharp contrast to
mammals, the lungs of these creatures have been created to make best
use of the sparse oxygen supply at these altitudes.
The skimmer lacks oil protecting its feathers from water. Therefore,
it does not dive for its prey. Its lower bill is longer and sensitive
to touch. Its wings are shaped such that it can fly very close to
the surface of the water for a long time without flapping its wings.
It dips its lower bill in the water and flies while using this technique.
It captures any prey that its lowered bill hits.
Slope soaring depends on the movement of air rising to the hilltop.
|Vortex ring type thermal soaring takes place under the base of a
big cumulus cloud.
Columnar type thermal soaring is only possible in warm regions.
Gust soaring is possible where two fronts meet.
|The visual faculties of birds hunting
during the daytime are far superior to humans. A human can see a rat
in the distance as a blur without focus, whereas a falcon can see
the same animal at same distance in much greater detail.
|The eyes of an owl are located to the front
of its head. This design provides the bird with a superb "binocular"
vision. Yet it also creates a wide blind field. This blind field
is by no means disadvantageous to the bird since it can rotate
its head 270 degrees and look behind itself easily.
( left) Eyes located on both sides of head
provide the pigeon with a very wide visual field (orange and
(right) The rain bird moves extremely fast
with swift manoeuvres in the air, which requires an even wider
visual field than most birds. Large eyes located on both sides
of its head provide this field of vision.
The woodpecker can easily reach larva hidden in tree trunks by
its tongue. Humming birds can collect flower nectar by using their
slim, forked tongues.
For some birds, a keen sense of smell is vitally important. The
black vulture can locate carcasses from great distances because
of its advanced sense of smell.
most advanced senses of birds are vision and hearing. Birds that usually
hunt by day have better visual faculties. The hearing of birds that
prey at night is superior to other faculties.Some birds that hunt by
diving, such as herons and cormorants, are equipped with eye structures
that enable them to see effectively in water. The cornea of their eyes
is flatter, which gives refraction and better vision. The eyes of most
birds are located on both sides of the head. Hence, they have a wide
angle of view. The frontal location of the eyes of wild birds that prey
at night is another flawless design because these birds require "binocular"
vision more than a wide angle view, and binocular vision (the area in
which both eyes can see an object) has a narrow angle of view but more
depth and focus just as does human vision. Birds have other interesting
senses as well, which enable them not only to perceive vibrations in
the air but also to navigate their routes by following the magnetic
fields of the earth.
PERFECT DESIGNS FOR FLYING, SWIMMING AND RUNNING
The skeletons of birds are designed to effectively enable them to fly,
walk and even swim in the fastest and most efficient way.
All flying birds are equipped with an extremely strong breastbone (sternum)which
has a large flattened plate, called a keel, for the attachment of flight
muscles. The muscles wrapping this bone facilitate flight.
The part of the skeleton called the breast plate constitutes a very sturdy
support for the wing bones, and is comprised of the breast bone and wishbone
that is unique to birds. The bones that carry the wings are very long
and fused together. The wing tip feathers attach to the fused "hand" bones.
The pelvic girdle extends both downward and backward in order to enable
the leg muscles to work more effectively.
The breast bones of birds are relatively inflexible for protection
of the body when the wings are closed. That is, the volume of the
rib cage does not change during flight, inhalation or exhalation.
Since birds are designed for the purpose of flight, their
bones are hollow and wrapped with muscles, which provide miraculous
lightness without compromising strength.
||The wings are pulled downward by the
contracting muscles. When the wings are raised and the small breast
muscles (supracoracoideus) are contracted, the large breast muscles
(pectoralis major) are flexed. When the large breast muscles are contracted
and the small breast muscles are flexed, the wings are lowered.
"Running birds", such as the ostrich, have long
legs and strong muscles that function in running, whereas predator
birds have shortened bodies and relatively spinal cord sloped, which
enables them to move more swiftly.
have keeled sternum that enables them to fly for extended periods.
This bone is covered with breast muscles.
Praise be to Allah,
to Whom everything in the heavens and everything in the earth belongs.
Praise will be His in the Hereafter. He is the Wise, the Informed.
He knows what penetrates the earth and what issues from it, and
what falls down from the sky and what soars up into it. He is the
Most Merciful, the Ever-Forgiving." (Surah Saba': 1-2)
||A night owl, with a wingspan
of 21.7 inches (55 centimetres), is an ideal night hunter. Its large
eyes are lodged in the front its head. This location is very advantageous
in its finding its prey. Another property of its eyes is the capability
for night vision.
||In addition, owls can rotate
their heads three-quarters of the way around, which further adds to
the size of their visual field. The ears of this bird are also very
sensitive. It can hear from its place on the branch of a tree the
quite noises that a rat makes in the bushes. It can flap its wings
virtually without a sound. The owl latches on to trees or to its prey
with large and powerful claws. One easily sees that this creature
is created as the ideal night predator.
Humankind made a
tremendous leap in flight technology in the 20th century. One of
the key ingredients in this advance was the study by scientists
of the designs found of the bodies of birds. In the design of aircraft,
many aerodynamic principles found in birds are implemented, leading
to very successful applications. This is due to the flawless creation
of birds, just as in the perfection evident in the rest of the creation.
DESIGN IN BIRD EGGS
The miraculous creation of birds does not end with wings, feathers or
their migration skills. Another extraordinary design feature of these
creatures is in their eggs.
However ordinary it may seem to us, the egg of a chicken has about fifteen
thousand pores resembling dimples on a golf ball. The spongy structure
of smaller eggs can only be observed under the microscope. These spongy
structures give eggs added flexibility and increase their resistance to
An egg is a miracle of packaging. It supplies all the nutrients and water
that the developing foetus needs. The yolk of the egg stores protein,
fats, vitamins and minerals, and the white works as a reservoir of fluid.
The developing chick needs to inhale oxygen and exhale carbon dioxide.
It also requires a source of heat, calcium for its bone development, protection
of its fluids, protection against bacteria and physical impact. The eggshell
provides all of these for the chick, which breathes through a membranous
sac that develops in the embryo. Blood vessels in this sac bring oxygen
to the embryo and take carbon dioxide away.
Eggshells are amazingly thin and sturdy, and so transmit the body heat
of the brooding parent.
|Chicks have a special "egg tooth" that they use
only to hatch the egg. This tooth is formed just before hatching and,
amazingly, disappears after hatching.
The eggshell is strong enough to protect the
embryo during twenty days of incubation. However, it is also easily
breakable so that the chick can emerge.
A Necessary Loss
During incubation, the egg loses 16% of its water content in the form of
evaporation. Scientists long believed this to be harmful and due to the
porous structure of the eggshell. However, the most recent research shows
this loss to be necessary for the chick to emerge from the egg. The chick
needs oxygen and space to be able to move its head just enough to crack
the shell while hatching. The evaporation of water creates the room and
Furthermore, water loss ratio is adjusted to vary between 15 to 20% for
ideal conditions depending on the type of eggshell. For instance, water
loss in the eggs of loons is a few times higher than in others that incubate
under dryer conditions.
The Design of an Egg for Durability
The durability of an eggshell is as crucial as its functioning in terms
of air, water and heat. It has to withstand external impact as well as
the weight of the incubating parent.
A closer examination reveals that eggs are designed for sufficient durability.
Allah created smaller and larger eggs different from one another. Eggs
of larger birds are usually harder and less flexible whereas eggs of smaller
birds are softer and more elastic.
Chicken eggs are rigid and rough, but they do not break when falling
over one another. The rigid shell also protects them from attack. If smaller
eggs were to be as rigid and rough as the chicken egg, they would have
broken much easier. Studies show smaller eggs are not rigid, but sturdy
and flexible, which prevents them from breaking under impact.
The flexibility in the structure of an egg not only
serves to protect the chick but also determines the way that the chick
hatches it. A chick that will come out of a rigid and rough shell
only needs to open a couple of holes at the blunt end of the egg before
pushing its head and legs out. The chick meets the world by lifting
the hat-shaped end cover that is formed by the cracks connecting these
|The figure shows phases of development
of a chicken egg in the ovary. It takes about fifteen to sixteen hours
for a chicken egg to form after fertilisation.
|Eggshells are created in such a way as to supply
oxygen to the chick inside through the porous holes. The figure above
illustrates the passage of carbon dioxide, water and oxygen through
(left) The figure above shows the shell of the
loon egg laid on wet and muddy ground. The shell is covered with
a layer called the "inorganic spheres layer", which prevents the
pores from closing and the chick from suffocating.
(right) The eggs of birds living under different conditions vary
as well. The figure above shows the section of an eggshell of the
egg of a rainbird. The specially crystallised outer layer protects
the egg, where it is laid in a gravel bed, against impact and scratches.
Eggs of many birds are created with camouflage
colours. Loon eggs resemble the form of a pear, which is the ideal
shape for sharp rock formations. When they receive an impact, they
do not fall easily but roll around in circles.