Saturday, March 15, 2008

The Mystery of Migration

Have you ever pondered the migration flight of millions of birds twice a year from one hemisphere to another?

This has always been a mystery to man, and scientists continue to study the phenomenon. All through the month of April and the first weeks of May these midgets of forest, field and lawn flow into the United States from tropical wintering grounds.

The late Dr. Eugene Odom, a zoologist, and his associates at the University of Georgia in Athens made contributions toward a full explanation of the mysteries. The fact is only God and the bird know how he gets from wherever he is to wherever he is going

Man asks, how can they fly so far without refueling? Studies show birds store fat, their "high test gasoline," in separate parts of their body, or "spare gas tanks". Man, lacking such a container, spreads his out all through his body.

A migratory bird is thus analogous to the airplane in that "high octane" fuel is added to and used from preexisting "tanks" without appreciable change in the tissue structure of the body as a whole.

This added fat is stored in empty spaces throughout the bird's tissues, much as extra gasoline is stored in the plane's tanks. Because it is not spread through the bird's body, the stored fat is completely independent of the bird's functioning parts.

A migrating bird's fat is "high octane" fuel. A human's fat is only a disfiguring bulge. A bird uses up the spare fat in flight and doesn't have to join the local Weight Watcher's Club once they arrive. Oh, to be a bird when the battle of the bulge attacks.

The how-come mystery of migration was addressed by Odom some years ago. He demonstrated that before migrating these birds build up their fat until their weight is doubled or even tripled, and this fat is the sole source of their long flight energy. No vitamins for these long distances fliers.

We can vouch that hummingbirds get fat before leaving for the tropics. We have from two to five nectar feeding tubes hanging in the kitchen window all through the migration period. In July and August, they come to the tubes, sleek and slim. We watch them grow fat. By the time they leave in September they are "totin' fat" and probably weigh three times their weight of July. By the time they reach their destination, the extra fat (fuel) has been used.

The energy system of man is based on glycogen, a carbohydrate. The fat-based system of a bird functions much better for them.

The available energy of a bird is greater per unit of weight than in humans, the storage capacity greater, and water balance is facilitated because fat, unlike proteins or carbohydrates, can be stored "dry" yet yields water on combustion, scientists explain.

At the current price of gasoline, wouldn't it be wonderful if all the fat and calories in our pizzas and burgers could be stored in an extra tank for the family car or lawn mower?