The swallow has always been a very auspicious bird in people's hearts, and in addition to the ordinary swallows we see that like to nest under the eaves of the countryside, there is a special swallow called "swift", which is also often called "footless bird".
This swallow flies and sleeps all its life, and once it lands, it is like death, so how does it reproduce? Is it really born without feet?
Let's take a look at what an extraordinary experience Swift has had with its life and flight.
Chase the frolicking swifts
Swift's statement
Birds of the Swift family are collectively known as Swifts, and they also have another nickname called Lou Swallow, which is distributed all over the world. There are many species under the Swift family, such as alpine swifts, ordinary swifts, white-waisted swifts, and so on.
In the case of ordinary swifts, for example, their feathers are very plain, dark brown. Don't look at them as ordinary-looking, but with their super flying ability, they are squeezed into the bird flight ranking. The Swift that flies with its wings outstretched is like two scythes, which looks quite beautiful.
The wings are shaped like scythes
Of course, Swift is a very typical migratory bird, and Swifts living at high latitudes travel long distances from north to south every year.
Take, for example, swifts living in Beijing, when researchers placed tiny light-sensitive locators weighing only 0.65 grams on their backs to monitor their migration paths.
Eventually, it was found that the swifts flew northwest from beijing's Summer Palace, passing through Inner Mongolia and Xinjiang, and then flew southwest across the border. They later crossed the Red Sea into Africa, headed south, and finally reached South Africa after a 3-month flight.
Migration path of the Beijing Swift
According to statistics, the migration has flown at least 38,000 kilometers, which is about the length of the Earth's equator. It is unimaginable that a bird weighing only a few dozen grams can have the perseverance to fly so far and repeat this behavior every year.
Therefore, many people think that Swift really loves flying. It is no exaggeration to say that they really yearn for the blue sky and belong to the creatures of the blue sky.
Fly while sleeping
Earlier we mentioned that the researchers tracked the migration trajectory of swifts and finally came up with the distance they flew. The flight began in late July and ended at the end of October, and being able to fly so far in such a short period of time proves that Swift's flying ability is indeed good.
White-waisted swift in flight
According to the results of the study, the swift can fly at a speed of 48 m/s and about 172.8 km/h.
Of course, they will not always maintain ultra-high speed flight, so general statistics will point out that swifts fly flat at a speed of 112 km / h, which can also be regarded as a master of birds.
Of course, it should be noted that many people will use the speed of the swift to compare the speed of the swift with the speed of birds of prey such as the falcon when swooping, pointing out that it does not fly fast. This comparison is meaningless, because Swift is a master of long-distance flight and is a famous "marathon" runner in the animal kingdom.
A bird of prey with equally strong flight capabilities
In the process of migration, swifts sometimes fly continuously in order to catch the road, and the number of days of continuous flight can even reach 9 days.
Maybe everyone sees this and thinks that Swift's small body also hides too much energy, and it can fly for so long without sleep, food or drink. In fact, this is not the case, Swift will complete things such as sleeping and eating during the flight, and is an excellent "multi-purpose" player.
The body structure of the swift
First of all, let's talk about how Swifts can sleep while flying, and they use the "hemi-brain slow wave sleep" method.
This means that while they sleep, only half of their brains are resting, and the other half continues to work. And we mentioned the swift's smooth figure and sickle-like wings in the previous article, which can help them glide with the wind at a certain height.
At this time, it often does not take too much effort to fly forward, so Swift can easily sleep and fly.
Unique hemi-brain slow-wave sleep
As for predation and drinking, they can also be completed in flight. Because swifts' staple food is originally a variety of insects in the air, it is not difficult for them to cook while flying.
As for drinking water, some people may wonder if this guy waits for it to rain and then opens his mouth to drink something by the way. That's not so exaggerated, but swifts don't drink water like ordinary birds, and they need to stand on the shore or on stones and replenish them all at once. Instead, when flying over the lake, dragonflies skimmed like water.
Drink water without stopping
The problem of eating and sleeping has finally been solved, so how does the non-stop swift mate and reproduce?
This can be divided into many situations, but in general, mating can indeed be completed during the flight. If you see swifts "slipping" in the air and sticking to each other, it means they're mating.
Mating can also be done during flight
Of course, although mating can be completed in flight, but the nest laying eggs still have to stop flying, it is impossible to say that they will "lay eggs" in flight, and the little swift will not die before seeing this beautiful world.
However, due to the limitations of its own conditions, swifts will choose a variety of relatively high caves and crevices even if they nest, and rarely choose low eaves.
Zhao Xinru, an associate professor of zoology at Beijing Normal University, said, "Swifts are climbing birds, suitable for climbing on cliffs and caves, and can only be attached to the crevices and cave edges of the bare rocks of the mountain, swooping down from a high place while flapping their wings to take off." ”
Swifts prefer to perch on cliffs
Many people may not understand the meaning of climbing birds, which is actually the source of swift's nickname "footless bird", when in fact it is not without feet, but the feet are "disabled".
Why does the "legless bird" land like death?
As we all know, birds' paws can be held against each other, which allows them to grasp branches and stay on the ground. The swift's 4 toes are indeed moving forward in unison, which means that not only can they not hold each other, but they do not have enough back pedaling force to land, and it is even difficult to stand firmly.
Disabled paws
So it is not that Swift is unwilling to stop and walk on the ground, but that the physical defect makes it difficult to take off again when it lands. For it, not being able to take off means not being able to eat or fetch water, in which case it is either reduced to someone else's meal or starved to death, which is equivalent to having been sentenced to death.
It is also for this reason that Swift often flies in the world of high-rise buildings, like some tall ancient buildings are their favorite nesting and staying places.
Many people living in Beijing say that in the last century, they could often hear swifts flying overhead with sharp cries, or frolicking between ancient buildings, becoming a beautiful landscape.
Swifts flying among ancient complexes
It can be seen that the ancient Wang Xietang Qianyan should be accurately said to be Swift, not flying into the lives of ordinary people, mainly because the height of the house is not enough, so that their next take-off is restricted.
It is worth mentioning that the Beijing Swift, which has made many Chinese feel more close, has reduced its population a lot with the development of the city.
Beijing Swift's "Sharp Drop"
You may not know that Beijing was also called Yanjing in ancient times, which shows that swallows have an important role in the history of urban culture. It is said that people in the Yin Shang period believed that swallows were their ancestors and directly called them "Xuan Bird".
Swifts in flight
It can be said that Swift has accompanied Beijing through ups and downs, witnessing the rise and fall of one dynasty after another here. But now, they seem to have ushered in their own time of decline.
The reduction of ancient buildings in Beijing has caused a large number of swifts to lose their homes to inhabit, and in this case, they have gradually disappeared from people's vision.
"The inability of the Beijing Swift to find a suitable nest site is a profound reason for the sharp decline in its number." Xu Jiliang, deputy dean of the College of Nature Reserves of Beijing Forestry University, pointed out that for the purpose of cultural relics protection, to prevent the feces of birds such as sparrows from corroding the paint surface and wood, many ancient buildings have installed anti-finches in front of the gaps in the bucket arches.
Flocks of swifts flying towards the setting sun
Man and nature should be a harmonious and symbiotic existence, and these birds that have accompanied us through the vicissitudes should not disappear like this. So now the protection of Beijing Swift is steadily progressing, and when people see the unfortunate fallen Swift, they will take it to the tall buildings to create conditions for them to take off again.
Swift rescued by humans