Swallow is a common bird in the mainland, there are two kinds of swallows in the mainland, one is what we often call the house swallow, the family swallow is our most familiar, but also the closest to us birds, the house swallow usually nests under the eaves, winter fly to the mainland Hainan or Southeast Asia and other tropical regions for winter.
In addition to the house swallow, there is also a more common swallow, that is, swift, swift flying fast, loud, people can often see them flying rapidly in the high air, but rarely see them landing on the ground, this is because the toes of swifts are hook-shaped, not suitable for take-off on flat ground, usually need to jump down from a high place after taking off. Therefore, swifts are also called "footless birds".
On the mainland, the swifts that people usually see are the Beijing Swift, which is the Beijing subspecies of the common swift, which is the only wild migratory bird in the world named after "Beijing". Beijing swifts usually nest on cliffs or tall buildings, and are not as often close to humans as domestic swallows, so they are not familiar to people. Today we will take a look at some of the characteristics of the Beijing Swift.
Regarding the basic living habits of the Beijing Swift, many documents have recorded that in March and April every year, the Beijing Swift will fly back to Beijing to nest, and in July and August, it will embark on a route to southern Africa to overwinter, and the whole round trip is more than 30,000 kilometers.
This distant and mysterious migration route has always been a mystery in the minds of many people, how they are located, where they have passed, whether there is a suitable foothold, etc., these mysteries affect the hearts of every bird lover. Fortunately, a recent research team of Chinese and foreign experts has completed the mystery of these mysteries in four years.
Between 2014 and 2018, a team of experts from Sun Yat-sen University, Beijing Normal University, Lund University in Sweden, the British Swift Action team, and the Royal Institute of Natural Sciences in Belgium spent four years studying the migration behavior of Swifts in Beijing.
The researchers read the flight data of the Beijing Swift by wearing a miniature light-sensitive locator, which is very lightweight and does not have much impact on the long-distance flight of the Swift. Over the course of more than four years, researchers installed a total of 66 Beijing Swifts with positioning devices, of which 25 Swifts successfully returned data, which became the key to uncovering the migration behavior of Beijing Swifts.
The data shows that the Beijing Swift has chosen an extremely distant and arduous migration route.
Route back to breeding grounds: Beginning in mid-February each year, the Beijing Swift, which winters in southern Africa, begins to move northward, almost in large groups, disappearing from southern Africa without a trace in a short period of time. As the northern climate gradually becomes warmer and food such as flying insects becomes more abundant, the Beijing Swift will stay near the Congo Basin for more than a month, waiting for the climate to warm further.
By mid-March, the Beijing Swifts migrated again, quickly turning northeast, leaving Africa in early April, and then non-stop, day and night, predation and rest in the air, until late April, returning to Beijing, one way for 64 days, a distance of 13,572 kilometers.
The breeding grounds of the Beijing Swift are mainly concentrated in the northern part of the mainland, and some of them will breed in the West Asia region, and at the end of the route back to the breeding ground, the large population of beijing swifts will gradually disperse and scatter to their respective breeding grounds. Like the house swallow, the Beijing swift has a strong memory and is a more "loving" migratory bird, usually returning to its birthplace to breed.
Route to overwinter in Africa: With the end of the breeding period, by mid-July, the Beijing Swift began to leave the breeding grounds, flying all the way to the northwest, flying over Mongolia, xinjiang, from the Junggar Basin into Central Asia, and then all the way to the south, flying over the Red Sea in mid-August, arriving in northern Africa in early September, after resting in the Congo Basin for about 40 days, setting off south again, and arriving in November to the wintering ground - the South African plateau located in the southern region of Africa at an altitude of about 1000 meters. The entire wintering activity lasted about 100 days and ended.
It can be seen from the comprehensive round-trip route that the Beijing Swift does not migrate non-stop, but will choose several locations for a short pause, the main stops are the Congo Basin, the southwest coast of the Red Sea and the southern shore of the Caspian Sea. In addition, the rate of return to breeding grounds is obviously much faster than the rate of returning to wintering grounds.
In the return route of the Beijing Swift, there will only be 1 or 2 stops, about 36 days, and it will take 64 days to return to the breeding ground. The journey to the wintering ground is significantly slower, with 2 to 6 stops, about 71 days, and the whole journey takes about 4 months.
The reason why Beijing Swift adopts a more direct migration route and faster migration speed in the spring return process is mainly for two reasons, one is because of different needs, the breeding period is the most important season for Swift, and it is also the season when food is most abundant, so the return need is more urgent. On the one hand, when wintering, it is necessary to take care of the newly grown little swifts, on the other hand, the lifestyle of the Beijing swifts in the wintering place is similar to wandering, concentrated in cliffs and other places, so there is no urgent need to arrive.
The migration route is not only far away, but also full of dangers, predators waiting for opportunities, and even humans are not far behind.
Compared with other swifts, the Beijing swift is a more drought-tolerant bird, with lower rainfall in its breeding grounds and crossing many deserts such as the Sahara Desert during migration. The direct impetus for the migration of Beijing Swift is not the arrival of the cold season, but the demand for food, after the weather turns cold, the insects are significantly reduced, and the Beijing Swift is forced to choose to migrate to obtain sufficient food.
The entire migration route of the Beijing Swift is very far away, and many elderly Swifts have fallen on the way, which is why it is rare to see the dead individuals of swifts, most of which are scattered in the mountains and seas. In addition to the long distance, there are various predators waiting for opportunities along the way, and some small and medium-sized birds of prey such as peregrine falcons are always waiting for tired swallows to enter their predation range on the way.
In addition to predators, even humans are not far behind, although the continent has a tradition of protecting swallows since ancient times, but other regions do not have such a common understanding. Just after beijing swifts arrived at the wintering ground thousands of miles away, the local residents had already heard the sound. Since swifts' activities in wintering grounds are in the form of social settlements, there are often large flocks of swallows crowded together, making it convenient for locals to catch them.
In nigeria and other regions, people gather at the top of the mountains, holding large nets in their hands, ready to scatter flocks of swallows that are approaching, and in this case, many swifts have become food for humans. If the swallows under your roof don't return the following spring, then unfortunately, it may never come back, so let's remember them with tears.