The geese are one of our most familiar and unfamiliar animals, familiar because we learned in the primary school texts that it flies to the south every year, and in the process of migration, it will form a "human" glyph and a "one" shape, and in the annual migration season, we can also see them from above the sky.
Strange because everyone knows that swallows fly south, but do not know where the south is, I believe that everyone will feel very magical when they see the swallows flying south in the sky, and they can actually see this wonderful thing.
So why do swallows fly south in winter? They have to fly to the Great South for winter, and only come back after the winter has passed, where is the "South" where they fly?
01
Why do swallows fly south for the winter?
In fact, the reason why swallows fly south for the winter is because the winter in the north is cold and uninhabitable. Animal fur has a certain thermal insulation function, and the feathers on the swallow are also more prosperous and thick, and they actually have a certain resistance to the cold of winter, and they are not as fragile as we think.
In addition, in addition to the temperature of the swallows flying south over the winter, there is another important reason, that is, food problems.
Because in the winter, the food in the north is particularly scarce. Whenever it comes to winter, the north is full of depression, many plants have dried up after autumn, and some bugs except for hibernation are basically frozen to death.
Because the swallows could not find food, they basically starved to death if they stayed in the north, so they flew to the south to find food.
02
Where exactly is the South?
In fact, the south of the swallow flying is not the same as the south we understand, and the south we think of is the south of the Qinling Huai River, which is the southern region of China, but the south of the swallow fly is further south than this.
Swallow migration distribution map: East Asian swallows will fly to Southeast Asia and Australia; Central Asian swallows will fly to South Asia and India; European swallows will fly to Africa; North American swallows will fly to South America!
When autumn is getting stronger, the swallows will gradually integrate into large groups, with children and daughters riding a strong north wind to the south, most of the swallows in China will migrate all the way to the south, will reach Southeast Asia, Europe and other places for winter, some swallows even fly to South Africa.
Of course, there are also a small number of family swallows will stay in Hainan Island in southern Yunnan, China, so some southern friends may still be lucky to see the swallows in winter.
On the way to the south, the swallows will encounter many unknown difficulties, because the destination is very far away, in the migration process, some swallows may be due to physical weakness and accidentally fall behind, once left behind, they may never return to the original team.
Under normal circumstances, the swallows that have fallen behind have a miserable ending, crossing some wastelands and deserts alone, and may accidentally die because they can't find food and water.
03
When the swallows come back, are they still this year's swallows? Do they still know the way?
In fact, this problem is not only our doubts, as early as thousands of years, wise ancients not only discovered the law of swallows returning in autumn to spring, but also explained this question to us with experiments.
Legend has it that during the Spring and Autumn Period, the palace maids in the Wu Palace and a man named Fu Xian of the Jin Dynasty, in order to explore this law, cut off the claws of a swallow to see if it could still fly back to the same place in the spring of next year.
It is more surprising that the swallow with its claws and claws still flew back to its original place in the spring of the following year, in short, although the time of the south flight is different, the swallows of different communities also have their fixed wintering grounds, but generally where the swallows make the nest, they will return to this place in the next year.
At first, it was thought that swallows could use magnetic field induction to find their way home, but no matter what kind of explanation, it could not answer this question perfectly, so people could only extrapolate it to the swallow's amazing memory.
What do the friends think about this? Feel free to comment below.