What is the secret of birds migration ?
As a young child, I used to see flocks of wild geese fly in the blue sky in my homeland in the late summer and early autumn. Just as described in the textbook of primary school, “Autumn is coming and it is getting cooler. A flock of wild geese is flying southward, sometimes in the formation of the fork and sometimes in a line.”
One day at the turn of the rainy and the dry season this year, I was queuing at a service station in Zimbabwe, where petro was in short supply. Suddenly some noises in the sky caught my attention. I looked out of the car window and spotted a dozen crow-like birds perched on a large tree not very far. They flapped their wings and quacked and cawed. Out of curiosity and boredom, I began to watch them, figuring that they must be holding a meeting and discussing the implementation of a certain project. Unexpectedly, however, their callings attracted more and more birds of the same species from all directions. In less than half an hour,nearly a thousand birds had gathered. Suddenly they flew away from the big tree and hovered and rose higher and higher in the sky. I wondered whether they were holding a party in this manner of hovering. Or were they selecting “Miss International” with the most elegant flight?
I came out of the car and stood on the lawn beside the road, watching them. They were hovering higher and higher in the sky until they looked smaller and smaller. I wondered, “Are they competing for flying the highest?”
Unexpectedly, the birds that flew the highest suddenly flew northwest along a straight line. The others were still circling, but they also flew along the same straight line when they reached the same height, as if they had boarded a train and rode away along the fixed railway.
I finally came to realize after a hard thought that those must be migratory birds. At the beginning they clamored on the tree to hail the flock to fly together to a distant place. Later they flew by hovering in order to increase the altitude. When they reached a certain height, they met an air current ; it helped them to fly to the distance place more easily.
Oh, how clever the migratory birds are!
After returning home, I checked up some documents about migratory birds and discovered more surprising facts. For example, arctic terns build nests in the Arctic Circle. They fly to the South Pole at the turn of summer and autumn. They fly back to the North Pole in the next year. Every year they travel for 35200 kilometers.
There is an oriole called Blackpoll Warbler, small in size and weighs only 20-odd grams. Before autumn comes, it flies from Alaska, America to the east coast of Canada or New England, where it feasts on all the dainty food to increase its fat and strength. Then when it is turning cold, it begins a long journey of flight, first toward Africa, over the Atlantic Ocean, then after taking over an air current it turns to Brazil of South America. The whole journey is 3840 kilometers at an altitude of more than 6000 meters. The flight lasts four days and four nights.
The white storks in Europe fly 12,800 kilometers to spend the winter in South Africa. The long-tail cuckoos in New Zealand fly 6,400 kilometers to spend the winter in the Pacific islands. Seagulls in England’s Isle of Mann fly from Wales to Brazil at over 700 kilometers a day for 16 consecutive days. The wild geese fly over the Himalayas Mountains at an altitude of 9,000 meters.
What is more incredible is that generally the older generations of cuckoos start their journey earlier. Smaller cuckoos usually start their migration a few days later. Unaccompanied by their parents, small cuckoos make their first flight to a strange place and can fly to their destination inerrably and unite with their parents. On the contrary, young starlings set off earlier than their parents and reach their destination all by themselves.
I wonder how they know that the cold weather is coming. How do they know which day is suitable for flight? How do they know that there was an air current at an altitude of thousands meters? How do they know that this air current would carry them to their desired place? How do they know that that remote place is now a time of spring and flowers with sufficient food? What power had propelled them to embark upon such an epic journey across oceans? How do they travel round trip without going astray? How do they identify directions while flying? How do they find their habitat without accompanied and guided by their parents?
I searched for scientists’ explanations and found the following four major answers.
Something like a biological clock inside the migratory bird can sense the upcoming cold and the appropriate time to take off, and can calculate the position of the sun while flying in the sky and determine its direction and route of flying by continuously adjusting the angle between itself and the sun or stars with the help of the sun, the moon, and the stars.
An inherent meteorologist, migratory birds can determine the duration of life at the habitat and the time of migration according to such meteorological conditions as temperature, lighting, wind direction, and rainfall. They can choose a sunny day to begin their flight, adjust their flying manner according to the changes and fluctuations of wind directions and barometric pressures, and make use of the ascending air current for gliding to save their energy.
Extremely sensitive to geomagnetic waves, migratory birds can identify their directions according to geomagnetic waves and can decide the time of migration and habitat according to the geomagnetic information known to them.
Through millions of years of evolution, birds have gradually realized the rules governing the seasonal changes of climates and have formed a fixed pattern through generations of accumulation of experience and passed on the genetic information to each succeeding generation.
All the four explanations above seem reasonable, but a deeper analysis may discover that they are whimsical and fantastic talk.
According to the first explanation, it seems that migratory birds can calculate their own positions, identify their direction, and derive the direction and route of flight according to the position of the sun.
Then, how about the air current at an altitude of thousands meters? Migratory birds calculate it as well? Wow, migratory birds are far more intelligent than Einstein. A brain the size of a little finger can calculate the direction of the air current at an altitude of thousands meters in the sky without any instruments and measurements. It is too whimsical that birds can calculate the direction during the flight without the use of compasses, theodolites, boxes and needles, and calculators. This is rather absurd.
According to the second explanation, migratory birds are born meteorologists, who can take off on a sunny day by choosing different climatic conditions. Thus they are far brighter than all the scientists and engineers in the meteorological bureaus in the world. The problem is, in abnormal weather, when the area of migratory birds is inflicted with consecutive days of cloudy or rainy weather, the birds would have no choice but to miss the air current in the sky and wait for the arrival of the cold current. And what awaits them will certainly be death.
When swallows return from migration every spring, they can always return accurately to the nests they built the year before. It is said that the swallows in a small town in America always return at the dawn of March 29 in the following year. How shall we explain this?
The third explanation is a little mythical. Migratory birds can identify the direction through geomagnetic waves and can decide the time of migration and habitat according to the geomagnetic information known to them. Are we sure that migratory birds can get to know the existence of air current at an altitude of thousands meters as per the geomagnetic waves? How can they fly to the place where they stayed the year before instead of other places simply with the help of geomagnetic waves?
The fourth explanation is a typical theory of evolution and seems flawless.
As we have known from the chick’s breaking of egg shell described in the above section, the theory of evolution has been proved untenable in this aspect by the fact that the first chick hatched from the first egg laid by the first hen on the earth could break the shell without the inheritance of any genetic information and shell-breaking skills. Then is the theory tenable when comes to migratory birds?
Based on the radioactive isotope determination method, scientists believed: The earth is 4.6 billions years old, animals appeared about 1.8 billion years ago, invertebrates about 4.38 billions years ago, fish about 3.80 billions years ago, amphibians about 2.9 billions years ago, and reptiles about 2.45 billions years ago, dinosaurs died out about 1.35 billions years ago, mammals appeared around 65 million years ago, and man appeared about 1.6 million years ago.
First let’s not question the method of radioactive isotope measurement, and suppose the method is accurate. Then birds must have lived on earth for a few billion years. If the birds are clever enough to pass on to the next generation the information that enable them to identify the directions, choose the favorable habitats, fly from the North Pole to the South Pole, take advantage of the air current for flight in the sky, and accurately find the place where their former generations have stayed, then why haven’t they evolved into even more advanced animals in the period of a few billion years but are overtaken by humans who have rendered them inescapable from their air guns and the nets cast over them? Are they unwilling to go on with the evolution? Or are they suddenly stuck in the middle of evolution?
If we don’t believe in the Greatest Creator, we can only think randomly . The question of whether egg has appeared before the chick or the chick has appeared before egg will remain a mystery for another ten thousands of years.
Well, I would say migration of migratory birds is that everything in nature has their definite purposes and means of subsistence and that they each has features irreplaceable by other species. Otherwise, all will die out. What will happen if a tiger can both reign supreme in the mountain and soar in the sky? What if a mouse can dig holes and build nests on the tree? What if antelopes live on both grass and other animals? What if dogs can bear puppies and lay eggs? What if apple trees can produce both apples and watermelons? …
Wow! It’s really amazing !
The answer for migratory birds’ migration is—instinct, just like bees that build honeycombs with a rhombus bottom consisting of 109.28 degrees obtuse angles and 70.32 degrees acute angles.
What is instinct?