As autumn gets colder, the flocks of birds migrating south have disappeared from the sky. However, it is not clear to many of us exactly where they are flying. What exactly is the south of the birds in**? Why do they choose to spend the long winter there?
In fact, the reason for the southward migration of birds is not simply to escape the cold. As homeothermic animals, birds are very tolerant of low temperatures, and the cold winter is not the only or main motivation for them to fly south. It's all about food. When food is extremely scarce in the north, the abundant food resources in the south are an important driver for birds to migrate south.
So, where does the southward migration of birds end? Why did they choose there? What are the ecological mysteries behind this seasonal migration? Let's explore the mysteries of bird migration.
When winter arrives in the north, most of the insects are either dead or hibernating. For swallows, which feed on flying insects, this is equivalent to the rupture of the entire food chain. Faced with a severe existential crisis, swallows have to choose seasonal migration, which is not unique in the bird world.
The reason why swallows are highly dependent on flying insects is inseparable from their highly specialized body structure. Over time, swallows have evolved their wings to resemble scissors and can make complex maneuvers, their legs have become slender and slender, no longer suitable for walking on the ground, and their beaks have evolved into a wide shape, which is more conducive to catching insects in flight.
It can be seen that the swallows have fully adapted to the lifestyle of foraging in the air. When the food chain breaks, they lose the basis for survival. This survival strategy, which is highly dependent on a single food source, leaves swallows with the option of seasonal migration to escape colder regions with scarce resources and fly to more food-rich tropical regions to survive the storm.
While the tropics offer abundant food**, competition for survival is also fiercer. Conversely, the northern regions have longer summer daylight hours, allowing birds to forage more time, and the organisms here are smaller, providing a safer breeding environment. Therefore, swallows choose to endure the hardships of migration in order to have a better chance of survival.
Migration is a double-edged sword for swallows. The exhaustion of the journey is enormous, and many swallows die on the way due to the accumulation of insufficient fat. But this is the only way for the swallow species to reproduce. It is precisely because successful individuals are able to survive and reproduce through migration that this survival instinct is gradually fixed by natural selection.
AbsolutelyNot all birds have to migrate seasonally。For example, sparrows can use plant fruits to forage on the ground without the need to migrate. But for swallows, which are highly dependent on insects, this is both the result of evolution and the need for life. Although the process was full of dangers, it was this seemingly aimless migration journey that made the swallow species a miracle of reproduction.
Swallows are one of the longest migratory birds in the world. Every year they travel between Asia and Africa for up to 1 one-way tripMore than 20,000 km. How did Swallow complete such a long journey within the time limit? There is a mystery of nature in this.
The swallow migration is long and arduous, but every year they persist in completing this magical migration. Fly from the Northern Hemisphere to the Southern Hemisphere in search of the right "South". Different species of swallows, choose different "southern". Swifts and golden-rumped swifts in eastern China mainly fly to Southeast Asia for the winter. Swallows from Xinjiang fly farther south and can fly to South Asia and even Africa.
The Peking swift, for example, has a peculiar migratory route. When they take off from Beijing every August, it is the middle of summer and the heat is unbearable, and these little birds are about to start their long journey. The Beijing swift initially flew westward, soaring over the steppes of Inner Mongolia, and after a brief pause, flew into Xinjiang and shuttled through the Tianshan Mountains. In mid-August, the Beijing swift had already flown over the Pamirs and made its way to Pakistan. The climate here is getting cooler, and there are even glaciers in the mountains.
The Beijing Swift then continued southward, flying over the Indian subcontinent. Here, they experience the humidity and heat of the rainforest. After a short pause, the Beijing swift flew across the Indian Ocean and finally reached its destination in South Africa, the southern tip of the African continent, in early November. The one-way flight reached 14,733 kilometers, spanning three continents: Asia, Europe and Africa.
After arriving in South Africa, the Beijing swift can finally stop its tired wings and forage for food in the summer in the southern hemisphere. However, the good times did not last long, and when spring came in the northern hemisphere, insects on the other side of the country began to be activeBeijing Swift realizes it has to set off and return home. On the way back, they chose a different route to return north quickly, and it only took 64 days to return to Beijing. Because of the abundance of insects in the temperate regions of the northern hemisphere in spring and summer, Beijing swifts need to rush back to ensure that their offspring have enough food.
In March of the following year, Yanzi set off for his return voyage and flew back to Beijing by the same route. They will be able to return to their familiar homes around mid-April. The journey took eight months, during which they only made a brief stop in South Africa and flew the rest of the time.
This huge migration of nearly 30,000 kilometers has become instinctive for Beijing swifts. They are naturally good at flying and can prey on insects to replenish their stamina during flight. The fastest swifts can fly at speeds of up to 48 meters per second. Non-stop flight can reach more than 1,200 kilometers a day. In a lifetime, the Beijing Swift has a total flight mileage of up to 500,000 kilometers, which is equivalent to 12 kilometers around the equator of the earth5 laps,A legendary journey.
In nature, the legendary journey of the swallow Taihang, witnessing the resilience of life in the changing seasons. We look forward to the return of the swallows every spring, with beauty and hope.
How do swallows complete their migration of tens of thousands of kilometers in such a short time? Their unique survival skills play a key role in this. First of all, swallows can hunt during flight, and they are good at catching insects in the air to fill their bellies. This eliminates the need for frequent foraging on the ground and saves time. Secondly, the swallow flies at a very fast speed of up to 48 meters per second.
They can fly more than 1,000 kilometers a day, including more than 400 kilometers when you take a break. Finally, other physiological activities of the swallow, such as mating and sleeping, can also be completed during the flight, making the journey more coherent.
With these unique survival skills, swallows are able to complete their long migration journey between Asia and Africa every year. Despite the development of technology, it is still difficult to fully decipher the mysteries of nature, and the swallow migration tour is a vivid example of this. We should be in awe of nature and cherish such miracles.
However,There are many more that we don't know about the mystery of the swallow migration route. For example, why do they choose South Africa as their destination every year? What features of South Africa attract swallows? And how do you remember the route and be able to fly back and forth without errors? These questions require further scientific research.
At one point, researchers captured dozens of swallows in Beijing and installed satellite positioning devices on them. The experiment lasted two years. It was found thatThe routes of the different swallows are not exactly the same, and some fly northeast to Russia and then detour through West Asia into Africa. This shows that the swallow does not memorize the route mechanically, but can adjust to the environment at the time.
Another swallow, R00-3105, stands out. It first headed north into Mongolia and then westward, passing through Xinjiang into Central Asia. After passing Kyrgyzstan and Kazakhstan, it moved south into Iran, then from Iraq into Saudi Arabia, and finally in Africa. It took 2 and a half months for this swallow to fly over more than 20 countries, with a total distance of up to 250,000 km!
R00-3105's journey has impressed us with the swallow's adaptability. Not only does it memorize the correct general direction, but it also adapts to the local environment and chooses the best route. This precise sense of direction and topographical memory is an important part of their survival.
The swallow migration journey is full of unknowns and wonders, and the mysteries of nature are staged every year. I hope that in the future, researchers can unravel more mysteries and let us further understand and appreciate the miracle of life in this great migration.