The trouble with glass buildings

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.