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". 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 and hooks.

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:

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.

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.