Every year after the arrival of autumn and winter, a large number of birds fly to the south to overwinter in my country. Birds such as the black canopy, white crane, cygnet, gray crane and white-fronted goose do not forget to pass by Dongting Lake with rich water and grass every year. Some birds even start their long "overwintering journey" in August and September.
Swallows are the most common migratory birds. From August to November every year, swallows fly to the south to overwinter. The Qinling Mountains have always been regarded as the dividing line between the north and the south of my country. The south of the Qinling Mountains belongs to the south, but the strange thing is that swallows are rarely seen in the south in winter. Where do they fly?
The swallows that are known to have scissor tails actually have a large family, with 75 species, such as barn swallows, golden-rumped swallows, sharp-tailed swifts, brown swifts, concave-winged swallows, blue swallows, purple rock swallows, bicolor tree swallows, white-spotted swallows, white-eyed river swallows, floor swallows, etc. In my country, the main ones are barn swallows and swifts.
Every year in July and August, the breeding mission of swallows raising chicks comes to an end. The chicks have already acquired the ability to forage and fly. Together with their "mother", they look for a large amount of food to replenish their physical fitness and prepare for the flight to the south for overwintering, because the overwintering journey is very long and takes more than three months to fly.
After the breeding season, the swallows gather together to live a gregarious life. Especially before wintering, a large number of swallows gather together. The branches or wires are all covered with swallows, and the number even exceeds a thousand. It is like counting the numbers before development, and then fly south together.
Swallows are not big and mainly feed on small insects, such as mosquitoes, flies, locusts , butterflies, moths , earthworms , caterpillars, grasshoppers , etc. Because aircraft fly surprisingly fast, they catch food while flying. Of course, swallows sometimes eat some grains, such as wheat, sorghum and millet.
Whenever autumn and winter arrive, people find that there are no swallows at all. Even in the southernmost regions of my country, such as Jiangnan and South China, swallows are almost invisible. So where did they fly to?
In fact, the "South" where swallows go to the south to overwinter every year does not refer to the Jiangnan, South China and Southwest regions in southern my country, but refers to the tropical areas near the earth's equator. The area near the earth's equator is the area with the highest temperature on the earth, and is the real "south" in the hearts of overwintering swallows.
Chinese bird experts have tracked and studied the migration routes of Beijing swifts and installed GPS locators on many swifts. The results returned by the locators surprised the scientists. The final destination of the Beijing swifts overwintering is South Africa, which is thousands of miles away.
The Beijing Swift is the most common migratory bird in my country. It is not only active in the Beijing area, but can be seen in Eurasia at about 40 degrees north latitude. The straight-line distance between South Africa and Beijing in southern Africa is more than 12,000 kilometers, but the Beijing Swift does not directly cross the Indian Ocean to reach Africa.
According to the GPS locator, Beijing Swift departed from the Beijing area in August, but did not fly directly south, but flew northwest, passing through Inner Mongolia and Mongolia , and then entered my country's northwest Xinjiang, entering the Middle East along the Kunlun Mountains in the south of the Junggar Basin or the Tianshan Mountains in the north.
Swift first crossed the Persian Gulf in Zuo Dazhong in late September, crossed the Arabian Peninsula , and then crossed the Red Sea and entered Africa. Then it flew all the way to the southwest and arrived in South Africa in November. The whole journey covered nearly 15,000 kilometers and took more than 3 months.
Of course, for more than three months, the swift flew in and out, stopping every day to catch food to replenish energy before flying again.
Beijing Swifts stay in the warm South Africa for three months. When spring arrives in the northern hemisphere, Beijing Swifts return to their habitat along the original route and enter the peak breeding season. Therefore, in autumn and winter, almost no swallows can be seen in the north and south of our country. This is because they have flown to Africa, and Africa is their real "South".
Flying 15,000 kilometers in more than three months is an arduous journey for a swift that weighs only over 100 grams, and is also full of dangers. It may encounter natural enemies, abnormal weather, food shortages, etc. Many swifts died on the long journey to South Africa.
It is a natural phenomenon for swifts to go to the "South" to overwinter every year. It is the result of natural evolution and cannot be stopped by human power. Although the journey is dangerous, there is still a great chance of survival. If they do not go to distant Africa to overwinter, swifts will simply not be able to survive the cold winter. For interesting scientific exploration content, please follow the only WeChat public account: Interesting exploration
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