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Do they not see the birds committed to fly in the atmosphere of the sky? None holds them up in the air except God. This should be (sufficient) proof for people who believe. (16:79) That birds can fly and so efficiently is miraculous. In order to work, such a flying machine must be amazingly lightweight and yet incredibly tough and strong. To take off and maintain flight, the bird can’t be too heavy. Yet to survive the conditions faced in the air and the force of landing, it must be tough so as not to break on impact. These two qualities (lightness and toughness) are exactly how a bird is constructed. The skeletal framework of a bird is rigidly interconnected with a very sturdy spinal column of fused vertebrae. The neck is strong but incredibly flexible as it must have the strength to support the head (keeping it motionless when in flight) yet flexible and ready to swing it suddenly in any direction, bending far downward or upward to spot prey or predators. The number of vertebrae in a bird’s neck varies from long-necked to short-necked birds. This may sound obvious. But a mouse has the same number of cervical vertebrae as a giraffe (seven). Birds have a minimum of 11. Flexibility of the neck is achieved by a system of long bands of muscles and smaller muscles that are perfectly coordinated. From the slow turning of an owl’s head to the flash of a heron catching a fish, it’s a masterful machine. Bones in the bird are hollow and thin-walled for |
lightness with internal struts for support. All weight is concentrated toward the center of the bird. At that center is a very large breastbone to which are attached the pectoral muscles, the mighty muscles which drive the wings. Flight muscles may account for 25-30 percent of a bird’s weight, compared to pectoral muscles in the human which weigh less than one percent of total weight. These muscles working to drive the wings build up great heat. To counteract this, the bird has the most efficient respiratory system of any vertebrate. Rather than a single pair of lungs the bird has a system of air sacs throughout the body even in some of the hollow spaces in the bones. The air is taken in quickly to all important parts of the body and the bird’s faster heartbeat provides rapid circulation. Good eyesight is an important prerequisite of flight. A bird relies more heavily on vision than most animals. In some birds their eyes actually weigh more than their brains. Birds can see distant things as much as eight times more clearly than man can, and they also see close up much better. Most birds have both monocular and binocular vision. They can rely on what one eye sees close up and then count on sharper binocular vision for distances. Have they not seen the birds above them lined up in columns and spreading their wings? The Most Gracious is the One who holds them in the air. He is Seer of all things. (67:19) |
Most important to flight are the wings and feathers. The wing is really an arm with a large ball joint fitting into the socket in the shoulder. This is a specialized joint allowing great mobility. The way the bird can rotate as well as flap up and down gives the bird the ability to maneuver, slow down, change direction suddenly and land gracefully. The feather is a unique and wonderful creation. It’s light yet sturdy, flexible, versatile and easy to care for, provides cushioning, thermal insulation, and is water repellent and replaceable. Bright colored feathers are important in some bird species for attracting a mate and territorial displays. Some birds have feathers camouflaged like their surroundings to help them hide. The simple looking feather is actually a very complex mechanism. There is a center shaft attached to the skin. From this project many parallel branches or barbs which in turn bear smaller barbules, which are equipped with hooks and barbs. All of these barbs catch in one another like little zippers forming a smooth surface. If the feather is ruffled and the connection broken, it’s easily smoothed out and rehooked. On each feather there are millions of these barbules hooking the feather together. When the wings are folded the feathers lie over one another like roof shingles with air spaces between to insulate against heat loss. Continued on page 4 |
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