Everyone knows that swallows fly to , southern for winter every year. In the past, we thought that this south was the south of China, but we never thought that the "south" in the Swallow's target was actually the southern end of the world . Like the flying athletes among birds, Swift , they will travel thousands of miles to other continents to spend the winter, which is really shocking.
It is worth mentioning that these swifts who have been sleeping while flying all their lives have not yet sound "foot", which means that they land almost means death. So, today we will learn about this special bird and see how they live and reproduce.
Swifts can sleep while flying
Swifts, which are good at long-distance flight
Generally speaking, birds from the Swift family are collectively called swifts. They are a separate family in the order Swifts, and they fly very quickly.
Judging from the appearance of the swift, you will feel that it is no different from ordinary swallows. Their bodies are streamlined, with sharp and long wings and a forked tail.
But in fact, the feet of swifts are different from those of ordinary swallows, and they can even be said to be somewhat "disabled". Because their toes are short and all four toes are forward, this means that they cannot walk back and forth on the ground like normal birds, and it is difficult to grasp objects such as branches and wires. Once they land, it is difficult to fly again. For birds, it almost means death.
The basic characteristics of swifts, its feet are very special
Because the swift family is very large, they are still very wide distributed around the world. It can be said that except Antarctica, the swift family is spread all over the mainland . Whether in desert oasis, grassland, farm, forest or city, you can see swifts.
As a typical migratory bird, swifts migrate every year. However, the migrating distances of swifts living in different regions are often different. Swifts that breed in high-latitude areas often do not migrate only within that country or region. Transnational migration is normal, and sometimes even transcontinental migration.
Swifts living in Europe will migrate across the continent to Africa
For example, BeijingSwifts , these little guys will fly from Asia to Africa in a thousand miles and spend the winter there. Along the way, they were not afraid of wind and rain and kept flying at high speed.
According to the data disclosed in 2021 " China Science Daily ", people found that ordinary swifts can fly about 570 kilometers per day on average.
This flight distance may be affected by environmental factors and may fluctuate greatly. Because in the research records, they also found that the swifts fly 830 kilometers a day, setting a new record.
Scientists found that the flight speed of swifts has set a new record
Susanne Akesson of Lund University in Sweden said, "The flight speed of ordinary swifts is not particularly outstanding compared to other migratory birds (about 10 meters per second). But these strategies help improve overall migration speed. In addition, their selective use of tailwinds promotes higher migration speeds."
It is hard to imagine how a small bird with a body length of 9 to 25 cm traveled thousands of miles to the south and then flew back in the next year. According to people's observations, the secret to the long flight distance of the swift is that this guy in can "sleep while flying".
In research, people found that Swift cleverly adopted the " single hemisphere wave sleep" method. Simply put, it will only allow one hemisphere of the brain to enter a rest state when sleeping, while the other half will remain awake. In this case, Swift can easily achieve "one heart and two things".
Swifts can use the "single hemisphere slow wave sleep" method to sleep while rushing
In fact, in nature, there are many animals like swifts sleeping, such as whale , seals, dolphin and other . Taking whales as an example, this guy can continue swimming while sleeping and float to the water to breathe.
In addition, one of the special features of Swift is that can "glide" . When their brains are absolutely awake, they will fly higher, and then make a judgment on the "wind direction" along the way, trying to make themselves "glide with the wind". At this point, it will reduce the frequency of flapping its wings.
Swifts can make judgments on the wind direction and make gliding down the wind to save physical strength
So, how does this little guy who is sleeping while flying and persistent in flying prey and reproduce?
Swift predation and reproduction
Swifts can not only fly while sleeping, but also "eat while flying". It turns out that during its flight, it will use flying insects in the air as its food. Thanks to the special structure of the wings, they can eat a lot of bugs in the gap. In this case, it is rare to stop and forage, and even drinking water is done during flight.
Even if they drink water, they won’t land
According to the information, when the swift needs to drink water, it will approach the water surface, and then use its mouth to gently "click" the water surface a few times, which will be considered drinking water.
So, even if predation and drinking water can be accomplished by relying on the special structure of the body and special flight capabilities, is it okay to reproduce?
is really OK, because birds are mainly reproductive through cloaca . Therefore, during their flight, they can continuously adjust the positions of both sides to allow the male swift's genitals to enter the female swift's cloaca, and then they can complete the reproduction naturally, which is not as difficult as everyone thinks.
I have to say that Swift is also a "old driver" in the air and is relatively stable in "driving".
"Old Driver" Swifts can reproduce in the air
Of course, many swifts do not choose to reproduce in the air, but will enter the nest and then reproduce after establishing a nest. In this case, it is relatively easier and safer.
It is worth mentioning that swift is also the representative of monogamy . After the female is successfully conceived, the male swift will take care of her. Both parties will make some contributions to building nests and raising offspring, but female swifts are still mainly responsible for hatching.
Swift couple will support each other and raise their offspring together
When the little swift is born, their parents will be busy feeding it again. However, whether it is possible to successfully forage in nature is full of surprises. In this case, the little swift will occasionally starve. When its wings gradually become fuller, you can prepare for an independent life.
In addition, because the food of swifts is entirely dominated by insects, they are considered a kind of bird of good fortune, and plays a key role in inhibiting pests. Whether it is flies, mosquitoes, or toon elephants, as long as they can be eaten, they will never refuse any swifts.
Most of the pests are in the swift menu
However, with the acceleration of the urbanization process of the human world, some swifts are facing an unprecedented crisis. For example, the most famous Beijing Swift in our country, these little guys used to fly around in the ancient imperial city, but now they seem very rare.
Survival dilemma faced by swifts
Beijing swifts are representatives of swifts living in high latitude areas. They breed in Beijing and surrounding areas in spring, and in summer they will rush to the plateau in southwestern Africa to spend the winter there. This long migration journey takes twice a year, and the total mileage can reach more than 30,000 kilometers.
Beijing Swift migration route
Data shows that the whole one-way flight of Beijing Swift migration south is nearly 14,733 kilometers, taking about 111 days. It took a rest and a stop in the middle (actually a hovering flight, not landing) for about 71 days, with an average speed of 134 kilometers per day.
However, the number of Beijing Swifts that can be studied is decreasing. In 2001, there were only more than 3,000 s left, and in 2014 only more than 2,700 were observed. Later, people searched for many survey points, but rarely found their traces.
The number of Beijing swifts is decreasing
. As more and more ancient buildings are being demolished, more Beijing swifts have lost their homes. After all, their naturally disabled "foot" make them only hang on ancient eaves. Today's tall buildings do not provide them with any living space.
It can be seen from this that these "strong" little swallows may soon disappear into our lives.
These cute little creatures are about to disappear from our field of vision
