by Xinhua writer Yuan Quan
BEIJING, Nov. 2 (Xinhua) -- As she was waiting for her flight at a Chengdu airport, Cai Xiao noticed the tiny dead body of a yellow warbler lying on the ground outside an enormous window at the two-story terminal building.
The Shanghai bird-watcher then saw another two dead birds within a few meters and realized that they had died from crashing into the window. It was a phenomenon she has heard of but never seen before.
Deeply saddened by her discovery, Cai took photos of the dead animals and emailed them to a nationwide scientific survey of bird-window collisions that aims to gather data to provide evidence of the existence of this issue in China.
Li Binbin, an assistant professor of Environmental Sciences at Duke Kunshan University in Jiangsu Province, led the survey, working with several Chinese bird-watching societies starting from March this year. She said that, so far, they have found bird collisions recorded in most parts of the country, and of the 26 species involved, two-thirds were migratory birds. There was a higher number of recorded cases in cities like Guangzhou and Shanghai with a high density of buildings.
In its pursuit of spatial transparency, mankind has put up countless glass buildings, creating a nightmare for birds, which have trouble seeing glass. They see reflections in glass as open space and fly into it at full speed. Even at night, when the reflections are minimal, lighted windows can be disorienting to migratory birds, causing them to collide with skyscrapers.
Sometimes birds appear to recover from their injuries and fly away, but they may later suffer internal hemorrhaging and brain swelling that leads to death.
In the United States, up to 1 billion birds die each year from hitting windows. Although there is a lack of data, scientists estimate that the issue is on a similar scale in China, given that the country's east coast is on a major migratory route for birds.
Li launched the survey after witnessing a dozen bird collisions on campus. In 2018, the scholar and her students delivered a report to the university, recommending that it replace windows where most of the collisions happened.
The school authorities worried that such an effort would damage the aesthetics of the buildings. After several discussions, they compromised, using stickers to decorate windows and reduce glass reflections, Li recalled.
This simple effort resulted in collisions at the site being reduced to almost zero.
In the design plan for the second phase of the campus project, Li saw that several of her suggestions were adopted: lowering the use of large windows; adding window designs with strips or other patterns to reduce reflections; and renovating glass corridors.
A similar attempt has been made at Futian Mangrove Ecological Park in Shenzhen, a city with the world's second-highest number of buildings over 150 meters tall. In August 2020, local conservation worker Rong Canzhong attached customized bird-shaped stickers to break up the reflectivity of the glass in the park.
"As for the aesthetic problem, we already have solutions to this issue," Rong said, pointing to the range of attractive stickers on offer.
Meanwhile, an art studio has designed ultra-violet patterns for windows that can minimize bird collisions, as ultraviolet light is invisible to humans but visible to birds. This particular solution has already been applied to good effect on several buildings, and it avoids the problem of stickers obscuring people's view or harming a building's aesthetics.
Although awareness of the issue is still limited, the number of institutions seeking to implement solutions is growing.
The Cuihu National Urban Wetland Park in suburban Beijing has applied frosted film on its glass corridors to reduce reflections. At Peking University, researchers covered the glass balustrades with posters, wires and stickers after they found bird collisions.
Such efforts are part of an increasing awareness of the broader challenges faced by birds in urban areas, which both public and private bodies have been seeking to address.
Last year, Lanshan County in central China's Hunan Province, which is located on a migration route, turned off certain spotlights and street lamps so that birds would not become disoriented at night.
In 2019, a property developer in Beijing, together with environmental NGOs, launched a project to protect swifts by incorporating nesting places into building designs.
These efforts in combination are doing much to improve the lot of birds in China, and the work on modifying glass on existing buildings has already proved effective in reducing collisions.
According to scientists, greater improvements could be accomplished by promoting bird-safety criteria for use in China's construction sector.
In October, scholars from China and Britain published an article in the journal Science, calling for the expansion of green certifications for buildings to include features that mitigate bird collisions.
"Reducing the risk of bird collisions should be a key element of any city's sustainability vision, as it's one of the causes of biodiversity loss that is completely avoidable," said Terry Townshend, a British environmentalist who has been watching birds in Beijing for a decade and founded the Birding Beijing group for fellow enthusiasts.
For those concerned with the issue, the main question is how to raise awareness of the problem.
Li said the first step should be to gather enough data. So far, more than 130 individuals and 33 birding societies have reported bird collisions to her survey.
Data collected by volunteers -- or citizen scientists -- has several advantages over that gathered by professional researchers, including the amount of data and the speed of acquisition. Li noted that employing a network of volunteers has the added benefit of spreading knowledge about the topic.
Biodiversity protection in cities may require the joint efforts of wildlife workers, urban planners, architects and the general public, she said. Enditem