Issue 87 / May - June 2012
Perfection in the Physique of Birds
With bodies heavy for flying and light for diving into the water, birds push the limits of their physique. Let's take a close look at the artistry displayed in birds, which amaze thinking people with their wonderful flying techniques.
Able to dive into the water at a speed approaching 90 km, the kingfisher can grab its prey at this speed in a depth of 60 cm, instantly pivot back and then, using its wings as oars, surface above the water. In order not to lose its prey, the bird's precisely timed diving and surfacing takes place in three seconds.
A torpedo as light as a fly
The most basic factor that enables an animate creature to dive into the water is its body being heavier than the water. With a weight of 40 g and a length of 18 cm, the kingfisher (Alcedo atthis) should remain on top of the water and not be able to catch fish because it cannot dive. However, because God put the sustenance of this bird in the depths of the sea, He gave it the special diving ability. Able to dive into the water at a speed approaching 90 km, the kingfisher can grab its prey at this speed in a depth of 60 cm, instantly pivot back and then, using its wings as oars, surface above the water. In order not to lose its prey, the bird's precisely timed diving and surfacing takes place in three seconds. In a short period of time the kingfisher has traveled a distance 414 times its height. This shows that it can move as fast as a fighter aircraft. If we consider what the kingfisher does on a human scale, a person would be able to dive 26 meters in three seconds and then resurface with a prey the size of a sheepdog. Here another interesting point should be made. The fish the kingfisher wants to catch is actually in a different position than it would visually appear from the sky due to the difference of the degrees of deflection of light in water and air. Bereft of any knowledge of optics, how does this bird solve this problem of physics?
How heavy is a bird feather?
There are physical limits to bird's flying capabilities. In order for a bird to be able to fly, its weight should not be more than 15 kg. In order for birds heavier than this to fly, their wings have to be proportionately larger so it is difficult for this big a bird with heavy wings to fly. Male silent swans (Cygnus olor) weigh more than 14 kg; in fact, there are even some that weigh 20 kg. However, God compensated for this situation with a special structure. Like other birds, the silent swans have some bones filled with air and the inner part of these bones has been made stronger with small props. For this reason, the feathers and bones of these birds are one-tenth as heavy as their bodies. There are more than 12,000 muscle ligaments in the wings of swans to activate the feathers used in flying. Long (50 cm) wing feathers greatly increase the carriage surface of the wings. Each feather can carry 200 grams of weight during flight. For this reason, a swan that loses just one wing feather can no longer take flight. It takes 60 days for the feathers to be completely renewed.
Because the owl's ears were created asymmetrically (the right ear is higher), sounds reach the close ear 1/300,000 of a second earlier. This small amount of time difference is enough for the owl to determine the exact place of the source of the sound.
Are owls flying radar stations?
Under normal conditions it is not possible to hear the sound waves of a mouse eating a hazelnut in a hayloft. Possessing a sensitive receiver, owls are an exception. The facial structure of owls resembles the high tech early warning equipment on AWACS planes. Focusing on even the smallest sound wave just like a satellite antenna, this structure cannot be explained by the intelligence of an owl.
Because the owl's ears were created asymmetrically (the right ear is higher), sounds reach the close ear 1/300,000 of a second earlier. This small time difference is enough for the owl to determine the exact location of the source of the sound. Through the 95,000 nerve cells in the simultaneous hearing center, the brain imagines a 3-D image of the prey. Due to the anatomy of it 14 neck vertebrae (humans and other mammals have seven vertebrae), the owl was given the capability of turning its head 270 degrees and determining the exact position of its prey. While flying towards the place where the sound came from, the owl can constantly recalculate the position of the prey relative to its own position, even if the prey changes its place. As a result of this precise calculation, only three seconds passes between the moment the owl first heard the sound of the prey and the moment it makes its deadly attack.
Is there a mathematical formula for remaining alive?
The formula is this: 7-15-70. It is difficult to immediately understand what these three numbers mean. However, these numbers make it almost impossible for a starling to be caught by its enemies.
We can explain the meaning of these numbers as follows: Whatever 7 close neighbors do, imitate them; constantly fly at least 15 cm from them; do not ever fly more than 70 km per hour. There is one more rule: Keep your distance from all enemies. When these principles are followed, enormous protection follows.
Flocks of starlings are comprised of several thousands of birds that move like one organism. In less than a second, the flock's direction, size and breadth can change. In this situation their enemies do not have much of a chance against such a tight mass. For predatory birds need to determine their targets in order to catch their prey. The fast and sudden movements of the flock prevent attack from predatory birds. In spite of this, predators who attempt attack go back empty-handed. For acting like one body, this enormous flock encompasses the enemy in a counter current with the waves they create and narrow it down until the bird can no longer fly. Becoming dazed, the predatory bird has no choice but to fly away from the flock. This instructive action of the starlings brings to mind the Qur'anic verse: "There is not an animal (that lives) on the earth, not a being that flies on its wings, but (forms part of) communities like you" (6:38).
The world's best camera can see objects as big as a mouse from a height of 300 meters. This is an amazing thing, but even so, no camera can compare in any respect to an eagle's eyes.
Can eagles see from the side?
The world's best camera can see objects as big as a mouse from a height of 300 meters. This is an amazing thing, but even so, no camera can compare in any respect to an eagle's eyes. Eagles can clearly see their targets from a distance of more than 1,000 meters. Eagles can even see a fish in fine detail from this distance. This special quality bestowed upon eagles is something technology would have difficulty imitating. For the lens of the eagle's eye is soft contrary to human eyes' and it sees clearly more quickly and it more greatly magnifies its object. In addition, each of the eyes of the eagle has two separate vision centers. This allows the birds to see clearly both in front of them and at their sides. To attain this perfect vision, more than a million light receiving cells are on duty in each square millimeter of the retina. Comparing this to a human eye, a person has 200,000 cells in the same unit of space in the retina. Due to this structure of the retina and lens, an eagle's eyes are as large as a human being's eyes. If a human eye were to have the same capability, it would have to be as large as an apple. Because a human does not need to hunt like an eagle, he was not burdened with such big eyes.
How much can a brain be shaken?
G-force expresses changes in a body's weight caused by acceleration. For example, when a jet is climbing towards the sky, the gravity a pilot is subject to increases immensely and his blood puts a lot of pressure on the veins in his legs. A space vehicle has 3 G when it takes off; a war plane has an average of 10 G; and a car's peak force is 120 G when it crashes head on at full speed. With every peck, a woodpecker's beak reaches 1,200 G in a way that is hard to believe. In other words, it is like the bird's head hits a cement wall at a speed of 25 km per hour, and the woodpecker does this 20 times a second.
Experiencing pressures greater than 14 G is deadly for a human being. In comparison, woodpeckers have been given the ability to endure several hundred times what astronauts experience in their landings. This is only possible with a very special histological/anatomic structure and a skull created with perfect proportions. With the beak hitting a tree in a hard manner, a woodpecker's brain almost completely fills its skull in order to prevent a trauma from developing. Created with a spongy structure, its bone structure acts as a shock absorber. The head and nape of the neck muscles contract towards the place it has hit and the waves from the blow become harmless. Even the lower part of the tongue is wound around the skull once in order to secure the brain and protect it from shaking. This situation does not create a problem or difficulty for woodpeckers which hit their heads against trees for a handful of larva, for they have been prepared for these conditions in their creation.
Small birds creating the power of a hurricane
Having a spread of 35 cm between two wings when they are opened, swallows weigh less than a normal size lighter. At first glance the apparent body structure of swallows suggests that they should only display an average flight capability with their deficient ability to maneuver. However, when we go out into nature and see swallows soaring in the countryside, we see that the situation is not like that at all. With the amazing way in which they were created, swallows succeed in doing a job that appears to be almost impossible physically. These birds can pass with jet speed through a space only 2 cm wider than their bodies. They succeed in this by flapping their wings rhythmically without stopping. Researchers have determined that they do this by means of a wing structure that moves with a special mechanism. The upper part of the wings of swallows can turn the air into an eddy. With the pressure created by this eddy, a great power of lifting and balancing occurs. The birds virtually fly with the power of hurricanes. Until now, this style of flying was only known to exist with insects. By seemingly gluing their wings to their bodies with this wonderful mechanism bestowed by the Creator, swallows easily pass through difficult places. Consequently, swallows can make 90-degree turns at astonishing speeds. Supersonic planes also benefit by generating these same kind of mini-hurricanes.
Can there be flying submarines?
Every year in May, tens of thousands of sharks, whales and dolphins come to the South African coastlines because of the schools of sardines (Sardinella). However, the strongest sardine hunter is not under water; it is a bird eyeing its prey from 30 meters high. The northern gannet (Morus capensis) a much better hunter than other sea birds, has a perfect body structure. While even sharks can only catch one out of two prey, the northern gannet's perfect hunting techniques enable it to make a record success. The first reason for this is its reaching its target quickly and directly; the second reason is its being able to move about comfortably under water. These sea birds can go down 10 meters at first and then 20 meters by flapping their wings. They can dive at a speed of 120 km per hour. Their capability of holding oxygen-rich air in their air bags allows them to hunt up to one minute under water. Because they usually finish their prey under water, it is not common for them to bring it to the surface.
As research supported by technological possibilities increases, many more amazing biological mechanisms will be discovered. Doesn't it strain reason to explain the existence of animate creatures that continue life with such fine calculations by means of chance?