This is not an alarmist. Recently, a glass curtain wall was installed in a self-built house in Changping District, Beijing. Because the reflected sky scene was too realistic, the bird couldn't distinguish it and crashed into the wall and died.
According to the official website of the US Fish and Wildlife Service, the glass curtain wall has become the second biggest killer of birds, killing 360 million to 980 million birds on average every year. The British Trust of Ornithology estimates that there are 654.38 billion incidents of birds hitting the glass curtain wall in Britain every year, and one third of the birds die.
Many experts said in an interview with Science and Technology Daily that with the acceleration of urbanization, in addition to glass curtain walls, power lines, wind turbines and expressway have also become "reefs" for birds to fly.
Glass curtain wall has become the second biggest killer of birds.
The glass curtain wall of urban buildings is fashionable, reflecting the prosperous and modern light. However, this building material, which was popular a hundred years ago, is now becoming a bird killer.
In the Shanghai Museum of Natural History, a national second-class protected animal "Fairy Eight-color Shark" died because it hit the glass curtain wall. 20 15 10, dozens of birds were also found dead because they hit the glass curtain wall in a residential area of Yinquan Avenue in Xianning, Hubei Province.
During the annual migration season, a large number of migratory birds migrate through China, among which China's "East Asia-Australasia Migratory Bird Zone" migrates more than 50 million waterbirds every year.
"Most of the dead birds that hit the glass curtain wall are migratory birds. They are not familiar with the terrain, and sometimes the flight speed can reach tens of kilometers. Once you hit the hard glass curtain wall, your head will fall from the sky and your internal organs will fall. Injury, so after falling to the ground, heavy casualties. " Li Changkan, director of Henan Bird-related Fault Engineering Technology Research Center, told the Science and Technology Daily reporter that after birds perceive different signals in flight, they will integrate and analyze them in different nerve regions of the brain to form an accurate navigation map. Birds can use astronomical phenomena such as sun orientation, stars, polarized light, mountains, rivers and magnetic fields to determine the migration direction, while glass curtain walls will give birds an illusion.
"The sky reflected by the glass curtain wall is very transparent, which will make birds mistake it for the real sky; In addition, the sunlight reflected by the glass will cause temporary visual obstacles to birds, making them too late to escape; At night, birds like to fly to bright places, and the city lights reflect on the glass curtain wall, which will also give them an illusion. " Ma Zhijun, a professor at Fudan University's School of Life Sciences, said.
Building glass curtain wall to avoid bird migration passage.
The concept of glass curtain wall originated in the 1920s. "At that time, German architect Smith proposed that the architectural trend of the future city should be the glass curtain wall built by the steel structure skeleton, but due to the technical conditions at that time, the glass curtain wall was not widely popularized. With the improvement of high-strength steel and high-quality thick glass production technology, in the 1950s, new york and Chicago took the lead in popularizing glass curtain wall buildings, and a number of glass curtain wall buildings constituted the skyline of these two cities. " Qi zhou, a professor at the School of Architecture of Southeast University, told the Science and Technology Daily reporter that since then, the glass curtain wall has swept the world and taken to the streets of Europe and Southeast Asia, setting off a craze in Japan and New Zealand, and became popular in China after the reform and opening up. At present, the total number of glass curtain wall skyscrapers in China accounts for more than half of the world.
Zhou Qi used "light and thin" to describe the characteristics of glass curtain wall. "The glass curtain wall is lighter than the masonry structure and will not settle; Fast construction speed and high use efficiency; High land utilization rate, thin floors and high housing acquisition rate can alleviate the shortage of land; It can also reflect the blue sky and white clouds and add a lot of color to the urban landscape. "
However, qi zhou does not deny the shortcomings of the glass curtain wall. For example, poor thermal insulation and high energy consumption; It will refract sunlight to the opposite buildings and roads, which will interfere with the driver's line of sight at some specific angles and cause rear-end collision; Cause bird impact, etc. Qi zhou said that in order to prevent the glass curtain wall from being broken, the architect will calculate the impact force of the bird flying against the bird, which determines that if a bird hits the glass curtain wall, it is equivalent to an egg hitting a stone. "Because of these problems, the country does not encourage the use of glass curtain walls now, but it is not explicitly prohibited." Qi zhou said.
Since the glass curtain wall has great "lethality" to birds, how can we help birds avoid traps? Chang Li suggested putting reflective strips on the surface of buildings to remind birds to avoid traps. Ding Changqing, a professor at the School of Ecology and Nature Protection of Beijing Forestry University, suggested that glass curtain wall buildings should avoid the bird migration Passage before planning. If the glass curtain wall is not high enough, you can also try to plant trees nearby to cover it.
Qi zhou said that although there is no mandatory requirement for bird environmental assessment when building glass curtain wall buildings, managers in some cities have realized this problem.
Sanmenxia is the largest wintering white swan habitat in China. Every winter, the white swan from Siberia will spend the winter here. Qi zhou used to be an urban architectural consultant in Sanmenxia. "I have done an ecological environment assessment, and the local requirements prohibit the construction of high-rise buildings and glass curtain walls near the white swan habitat."
Power lines and wind turbines are also the "hardest hit" by birds.
In addition to glass curtain walls, other facilities in the city will also become bird killers.
Li Changkan pointed out that birds have keen vision, but when flying in poor light environments such as cloudy days and nights, especially during migration, it is easy to accidentally hit power lines and wind turbines.
"In China, near Lhasa and Urumqi, cranes and black-necked cranes often bump into power lines by mistake. He said that in bad weather, birds' sight was affected when flying. Once it hits the generator blade, the wings are easily broken and the probability of being killed is very high. Transmission lines are usually thin and difficult to be found by birds. Once hit by a bird, it is either killed or injured, or the effective insulation distance between lines is reduced and electrocuted. "
Ding Changqing introduced, "In addition, the flowering shrubs such as honeysuckle planted on both sides of the road will attract birds to gather for food, and when walking on both sides of the road, there will also be collisions, causing casualties. So he suggested that this shrub should not be planted on both sides of expressway.