Probably man has always envied the birds for their ability to fly. Throughout our history, man has been the earth-bound plodder, watching birds swoop and soar overhead. The ancient Greek legend of Icarus, who supposedly fastened feathers to his arms with wax, recalls our long frustration. According to the legend, Icarus was enabled to fly so high that the heat of the sun melted the wax, so that he fell to his death.
Actually, it takes a great deal more than borrowed feathers to make man able to fly, so we turned to mechanical aids – first the hot-air balloon and ultimately the space-going rocket. These are remarkable achievements, but still our mechanical flight falls far short of the freedom of unencumbered flight which birds enjoy.
How do birds do it? Thanks to many who have made the study of birds their life work, we now know a good deal about how birds fly. But the more we learn, the more obvious it becomes that flying, which comes so naturally to birds, is a very special gift which demands several major physical adaptations.
First, of course, we must mention wings. To gain the wings they need for flight, birds had to sacrifice the stability of four legs, or the usefulness of hands. This is because the bone structure of wings is the same as that which became forelegs or arms and hands in other animals, as well as man.
Secondly, birds’ bones are very different internally from those of other animals. They are hollow, in marked contrast to the heavy, marrow-filled bones of other animals and man. Not only are they hollow, they are also efficiently braced internally, so that they offer strength without much weight. This is important because every once of weight must be lifted in flight.
Of course, when we think of birds, we immediately think also of feathers. Feathers are a highly specialized development of the same substance that in other animals becomes horns or hooves or claws (or fingernails in man). What a unique creation feathers are! Like the bones, they are hollow, yet rigid and very strong. Extrusions of the horny material of which they are made become the beautifully detailed barbs, of which the vanes on both sides of the central shaft are formed. These barbs are hooked together, so that a continuous, cohesive surface is created which is capable of pushing against the air.
Normally, each bird is equipped with ten large flight feathers at the outer extremity of each wing. This portion of the wing corresponds to the “hand,” and is where most of the dynamics of flight take place. Most birds move their wings at three separate joints: shoulder, elbow and wrist. The inner portions of the wing provide lift, similar in function to an airplane’s wings. Continuing the comparison, the “hand” portion of the bird’s wing is its “propellers,” since they furnish the motive power.
All birds fly by flapping, but some do more dynamic gliding than flapping after they get well up into the air. Such birds as eagles, buzzards and condors can be observed to be almost motionless as they soar high above the earth. They are equipped with large high-lift wings, and are capable of riding on currents of warm air for hours. Perhaps the king of soaring birds is the albatross, of the far southern oceans. Gliding with the aid of its 11 ½ foot wingspread, the albatross patrols the trackless ocean for days and weeks on end, endlessly searching for food. During these long patrols, it seems to light on the water only to feed. It is believed to be able to sleep while on the wing.
There are many other adaptations which make flight possible for birds. For example, their wings are powered by strong breast muscles, comprising up to 25 percent of their total weight (30 percent in the case of hummingbirds). Interestingly, the meat of the flight muscles may be white or red, depending on how well supplied they are with blood vessels. Migratory birds, which must be able, in many cases, to fly hundreds of miles without stopping, are typically red-meated. White-meated birds are not capable of long-sustained flight, though they may fly very swiftly for short periods.
Finally, consider the fuel efficiency of birds. Tiny hummingbird are perhaps the most efficient: Ingesting only the nectar of flowers, they convert this sugar to fat for maximum storage of calories, and the convert the fat back to sugar just before it is oxidized (“burned”) to provide energy. Hummingbirds are migratory, and many of them fly non-stop for more than 500 miles across the Gulf of Mexico as they transit between summer and winter homes. It has been calculated that if hummingbirds were the size of men, they would consume approximately 155,000 calories per day. If a man had to create this much energy, he would need to eat 285 pounds of hamburger, or 130 pounds of bread, each day!
How can we account for all these specialized adaptations? Did front legs gradually transform into wings? We pity the poor changeling that had to cope with life for a few million years in the middle of the process! And, if this somehow happened, against all believability, where is the record in the fossils? There is none! When birds first appear in the fossils, they are fully birds. No transition forms have ever been found, though there should be myriads of intervening forms, each shading ever so gradually into the next, if evolution were true.
This is equally true of feathers. Feathers, when they first appeared, were true feathers in every sense of the word. Indeed, partial feathers would be useless for flight. The bird would be “grounded” until they developed. And what shall we say of hollow bones? How on earth did birds come up with that feature?
All of these adaptations were necessary, yet none could have come about by the slow process of evolution. There is only one way they could have all happened, and that is the way God’s Word says it happened: “God created the large sea creatures, and every living creature that moves, with which the waters swarmed, after their kind, and every winged bird after its kind. God saw that it was good.” (Genesis 1:21) In other words, they were birds from the very first, by deliberate design – God’s design.
The next time you see a bird in the air, recognize it as a beautiful creation of the God who made the world, and saw that it was good. To those who have eyes to see, all the earth becomes a vast symphony of praise to God. Praise His Name!
(All Scripture is quoted from the World English Bible translation.)