Nature’s Great Navigators
When the days and nights begin to get cooler, and the leaves begin to fall from the trees, we know that the hot summer months soon will be over. About that same time, flocks of birds often can be seen flying south as the colder months approach. Their movement from one place to another at certain times of the year is called "migration." Not all birds migrate when the seasons change, but those that do move at certain times of the year, in definite patterns, without the assistance of any navigational instruments at all.
Some of these birds travel great distances, over many days, to reach their destinations. The golden plover travels from Alaska to Hawaii for 88 hours over the Pacific Ocean—over 2,500 miles; it flies this great distance without stopping once for rest or food. A bird called the Manx shearwater can return to its nest in the British Isles, across the Atlantic Ocean in twelve and one half days—without stopping. The Arctic tern travels from the North Pole to the South Pole twice a year—a round-trip flight of more than 20,000 miles. The Japanese snipe travels over 6,000 miles from Japan to Tasmania (near Australia). The American sandpiper travels 10,000 miles from Alaska to Tierra del Fuego (on the southernmost tip of South America).
Scientists have tried many different experiments to try to confuse migratory birds. Instead of confusing the birds, the scientists themselves are astounded that, no matter how they try to trick them, the birds always follow the same migration patterns, and always start on their long journeys at the same times. Birds flying for long distances sometimes have to endure very difficult flying conditions, like fog, rain, thunderstorms, and changes of wind direction. Sometimes strong winds can blow the birds off course, and they are forced to land in new territory. Most of the time, the birds are off course only temporarily, and will resume their original travel pattern. This ability to stay on course is believed to be "instinctive"—that is, something programmed into their brains from birth.
Since birds that migrate must travel long distances without stopping to rest or "refuel" (find food), they must carry in their bodies the energy they need for their long journeys. This energy is provided from the fat in their bodies. They prepare for long trips by eating large amounts of food and building up the necessary fat, sometimes increasing their body weight by as much as 50%. They cannot overeat, or their bodies will be too heavy and use up too much energy for the long flight. They cannot eat too little, or they won’t have enough energy for the trip.
The birds also know how fast and how often to move their wings; every movement uses up their valuable energy supply. So they must be able to judge how long the trip is and how much energy to use in order to reach their destination safely.
How do these birds navigate from one place to another? How do they know exactly how much food to eat before they migrate? How do they know how to judge distances, and adjust their energy use accordingly? There is no logical explanation—except that the Designer of all birds, God the Creator, designed these wonderful, intelligent creatures just that way, in the beginning.