The southern water city gathers tens of thousands of migratory birds.
Wetland mudflats, surprised by strange footprints.
Where is the mysterious bird?
More than 2,000 years ago, Li Bing, the Taishou of Shu County, Qin, led the people to build a large-scale water conservancy project Dujiangyan, which made the Chengdu Plain smooth and rainy, and the fertile wilderness was thousands of miles.
Chengdu has a variety of landforms, longitudinal river networks, developed water systems, and rich products, and has been known as the "Country of Heavenly Capital" since ancient times. It provides an extremely good ecological environment for the habitat and reproduction of various organisms.
Birds and cities coexist in harmony
The three-toed footprint monster bird is now in Chengdu
In early 2018, a birdwatcher in Chengdu accidentally found a strangely shaped three-toed footprint on a beach on the outskirts of Chengdu while looking at birds in the wild.
Due to his many years of experience in bird watching, based on the depth and shape of the footprints, he speculated that this should be some kind of larger aquatic bird. However, large and medium-sized birds that appear near Chengdu have four toes. So, what exactly is the three-toed monster bird that has stayed on this beach?
He then asked other bird watchers for verification, and found that there were even people who had found three-toed footprints on the river beach. The birds that have left such footprints have not yet been observed. Birdwatchers decided to form bird watching teams and squat in the waters where the footprints were found.
For several consecutive days, the team found a variety of water birds on the wide water surface, including local resident birds in Chengdu, as well as short-staying migratory birds, and even observed the blue-headed diving duck, a critically endangered bird in the world. However, no traces of large bird activity have been found.
A globally endangered species with fewer than 500 blue-headed diving ducks
Is it a flamingo?
At this time, a team member photographed a strange-looking bird. They are huge, slender and straight, with a large curved hook-shaped beak, and their legs and neck are thin and long. Based on the photographs taken, birdwatchers believe they look very similar to flamingos. But more questions followed, if it was flamingos, why were their bodies gray-black?
The flamingo's feathers are mainly red, shiny and shiny, and from a distance, they look like a burning flame, so they are called flamingos. In 2008, scientists at Leiden University in the Netherlands and members of his experimental team found through precise calculations that flamingos, salmon, shrimp, crabs, etc. showed a seductive red color because their bodies were rich in a special substance called astaxanthin. Animals themselves are unable to synthesize astaxanthin, and shrimp and crabs mostly obtain astaxanthin by eating this algae and plankton. Flamingos, on the other hand, transmit astaxanthin by eating small shrimp, small fish, and algae, so that this feather emits a bright red color.
Will these black birds found by bird watchers be flamingos?
What is even more puzzling is that the flamingo is not a native bird of China, but is mainly distributed in Central America, South America, Africa, Southern Europe, Central Asia and western India. They are hardly seen in China, and even their migration routes do not pass through China.
So, what exactly are these birds?
The Panel launched an investigation
The discovery of the mysterious big bird has also attracted the attention of relevant experts. Not long ago, the film crew of "Geography China" came to Chengdu with experts to investigate.
Expert analysis, Chengdu Plain is a composite alluvial fan plain originating from the Northwest Sichuan Plateau such as the Minjiang River, the Tuojiang River and its tributaries, etc., the surface is loose, the terrain is flat, the soil is fertile, located in Chengdu, the river network is longitudinal, the products are rich, since ancient times enjoy the reputation of "the country of heaven", the excellent ecological environment base makes there are many species here, not only pandas, golden snub-nosed monkeys, wildebeest and many other rare animals under national key protection, but also many novel species.
Sancha Lake, Chengdu
Therefore, will the large gray-black bird found by bird watchers be a novelty species that has never been discovered?
After the analysis of Shen You, a researcher at the Chengdu Bird Watching Association, he explained that the flamingo actually has four toes, but because the hind toes have been basically degraded, very high off the ground, and the small ones can be ignored, the footprints that were found made people mistakenly think that it is a rare giant three-toed bird.
Teacher Shen's conclusion caused all the team members present to have huge doubts. Flamingos have bright feathers and are easy to distinguish, and these birds have dull feathers, how can they be flamingos?
At this moment, one of the birds in the video suddenly flared its wings, revealing red feathers under the wings. It was the details that appeared at this moment that made Shen You conclude that these 6 large black water birds that were strolling idly were flamingos.
How did the flamingo turn black?
In order to solve this puzzle, Professor Wang Yunsheng, a geological expert at Chengdu University of Technology, also joined the expedition team.
Professor Wang immediately tested the water quality through the instrument, and the result value was stable in the category of 7.7. He analyzed that the pH value is more ideal, and it can also be seen that the soluble solids containing soluble in the water are 0.24 mg per liter, which is relatively low, that is to say, the purification environment of the entire water is still very good.
Experts said that Chengdu is located in the middle reaches of the Minjiang River Basin, and the river water is mainly composed of atmospheric precipitation, underground undercurrents and snowmelt, and the territory is all freshwater water. He speculated that this was one of the important reasons for the change in flamingos' feathers. Due to the lack of plankton and algae in the brine environment, some small fish and shrimp do not have astaxanthin in their bodies. After flamingos eat astaxanthin-free foods, their feathers cannot turn red.
flamingo
Why are flamingos in Chengdu?
Flamingos are mainly distributed in Africa, Central Asia and other regions, preferring to inhabit the tropical saltwater lakes, swamps and shallow waters of lagoons, and there is almost no distribution record in China before. Why are these flamingos in Chengdu?
Shen You speculated that flamingos should be migratory birds that come to Chengdu wetlands to overwinter.
However, migratory birds have a relatively fixed route, and there is no previous record of flamingos migrating through China. So, what does it mean for flamingos to appear in the Chengdu Plain?
A good ecological background has created a paradise for birds
Under the leadership of Shen You, the inspection team came to Chengdu QinglongHu Wetland to carry out scientific research. Walking through the grass, suddenly, a cry caught Teacher Shen's attention. With the help of the high-powered telescope, Shen You found that the opposite shore was densely packed with flocks of herons, egrets and other heron birds.
Shen You said that because the egret itself belongs to the wetland birds, the requirements for water quality and ecological environment are very high, known as "the monitoring bird of the atmosphere and water quality status", enjoying the reputation of "environmental protection bird". We can know through birds like herons that this is an ecological environment dominated by wetlands, and this environment has also reached a certain degree of health, meeting a series of needs such as bird habitat, reproduction, and wintering.
Experts tell us that a good ecological background has built a paradise for birds, and Chengdu's efforts to protect the ecosystem have become a strong backing for birds. According to the "Chengdu Bird List", there are 466 species of birds in 20 orders and 78 families in Chengdu. The number of existing bird species accounts for about one-third of the total number of birds in the country, and the harmonious coexistence between man and nature is reflected here.
However, experts believe that good water quality and atmospheric conditions are only one of the basic conditions for attracting flamingos to stop, and they must have more critical factors in choosing to overwinter here.
In order to solve the puzzle, the experts led us to the waters of the Xiangjiang River, which is not far from Chengdu, to investigate. Soon after the march, Professor Wang made new discoveries.
Professor Wang: "You see this as if it were snake skin." The long tail should be a non-venomous snake, and the snake, as one end of the food chain, can survive well, indicating that the environment in this place has been greatly improved. ”
Expedition member: "Look, there's a frog here." ”
Professor Wang: "It shows that the ecological environment of this place is really good, it eats insects, and the next biological chain also exists." ”
Professor Wang told us that although the wetland only covers 6% of the earth's surface, it provides a living environment for 20% of the known species on the earth, with irreplaceable ecological functions, so it enjoys the reputation of "the kidney of the earth", and Chengdu wetland has a relatively complete biological chain system.
On the way to continue the expedition, a bare rock formation caught Professor Wang's attention.
Look west at the snow-capped mountains
Professor Wang "We can according to the direction of the arrangement of the boulders, you see this flat plane in this direction, then, from the perspective of river dynamics, it means that the ancient flow direction of the river at that time, flowing from this direction, is not much different from us now, that is, from the north west to the south and the east, this place can be seen that our west Sichuan Plain is actually this kind of river at a time, (bringing) the material of the mountainous areas into our basin. Forming a huge alluvial plain fan, this is actually such a plain on which the entire "Kingdom of Heavenly Palace" depends for survival. ”
Professor Wang: "With the downward cutting of the river and the uplift of the earth's crust, a large amount of humus is deposited, so that the Chengdu Plain has both suitable conditions for cultivation and fertile soil for vegetation growth. This provides a most basic geological condition for biological diversity.
The Chengdu Plain, formed by the alluvial of the Minjiang River and the Xiangjiang River, is the core area of the "Kingdom of Tianfu", with fertile soil, sufficient water sources, and a wide variety of biological resources, which provide a guarantee for flamingos to overwinter here, and also attract more novel species. ”
Shen You believes that especially at the level of ecological diversity, and the most representative of ecological diversity is birds. In fact, birds can largely reflect the construction of the entire wetland ecology as a result of reaching a level.
Where did the flamingos come from?
The superior natural environment of Chengdu's wetlands is an important factor in attracting many birds, including flamingos, to inhabit the area, but there is still a doubt that even if it is a long migration, flamingos rarely fly through China. After investigation, it was found that the flamingo appeared in Chengdu more than once. So what makes them deviate from the conventional route and settle on the Chengdu Plain?
To answer this question, experts have compiled data on the global climate in recent decades. Experts found that every time the flamingo appeared in Chengdu, it was after a long, widespread cooling. They were wrapped up in the polar cold currents, deviating from the original direction of migration and becoming "drifting birds". Experts explain that drifting birds are also migratory birds, but often move from habitat to habitat due to changes in climate and food. Flamingos appeared in Chengdu, most likely due to major natural climate changes, deviated from the original migration route, and finally came to the Chengdu Plain. Since most of the yaws are sub-adult birds whose bodies have not yet turned red, it is difficult to fly over the Qinghai-Tibet Plateau to continue migrating. At the same time, Chengdu's vast waters, abundant food sources, and good wetland habitats provide them with a guarantee of survival, so these flamingos stop here.
The park is a good example of the integration of man and nature in Chengdu
Nowadays, Chengdu, the country of Tianfu, which "follows people from water and drought, and does not know hunger", is vigorously promoting the construction of a beautiful and livable park city, building a global green space system, forming an ecological "green vein" that connects forest lakes and blends landscapes, and reproduces the beauty of the Tianfu artistic conception of the Minjiang River, the lush forests and bamboo cultivation, and the elegant charm of Shufeng. A good ecological background has created a paradise for birds, and Chengdu has increased its efforts to protect the ecosystem, allowing more citizens to witness the beauty and vitality that rare birds such as flamingos add to the city.
The Water of the Minjiang River, the cultivation of bamboo in Maolin, and the elegant charm of Shu style are the artistic conception of Tianfu
In addition, whether in the blue sky, clear water, pure land, or in the protection of wetlands and woodlands, Chengdu has made good achievements in recent years. With the global ecological resources as the "bottom", with nature as the "scenery", with culture as the "soul", with the transformation of production methods as the "core", with the comprehensive development of people as the "foundation", with the acceleration of the pace of chengdu's construction of a beautiful and livable park city, Chengdu's ecological environment has been greatly improved, and birds have been greatly improved, and the beautiful and livable park city is not only the livability of people, but also the harmonious coexistence of various animals and plants, making Chengdu a good example of the integration of man and nature.