Addressing the Perils of Bird Collisions: Architectural Innovations for Conservation
Enhancing bird safety in cities: Innovative solutions like bird-safe glass and light reduction measures can significantly reduce bird collisions, making urban environments safer for migrating birds
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In early October, over 1,000 birds died after colliding with the McCormick Place Lakeside Center in Chicago in a single day. The Lakeside Center, the largest convention center in North America, is an example of architectural modernism and was constructed in stages from 1960 to 2017, made of steel, concrete, and glass.
The buildings are not particularly tall according to contemporary standards, but their almost unbroken glass facade poses a problem for birds, especially at night when the brightly lit interiors confuse them. The thousand birds killed that day were just a small proportion of the millions of migratory birds moving southward across the continent to their wintering grounds, a journey undertaken twice yearly by these animals.
What makes this mass bird death unusual isn't the number of animals that died (the American Bird Conservancy estimates that up to a billion birds suffer the same fate every year), but the fact that it received so much public attention. This was due to the Chicago Bird Collision Monitors, a volunteer group that has been recording bird strikes in the city since 2003. According to their records, this was the largest number of dead birds recorded in the vicinity of one building over a single day.
The facade of Chicago's Aqua Tower was, in part, designed to stop birds flying into the its windows.
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To prevent bird strikes, it is important to focus on the design of glass buildings in urban areas. Chicago demonstrated this in 2009 with the completion of the Aqua Tower designed by US architect Jeanne Gang. The wave-like facade and fritted glass were specifically designed to reduce bird collisions by making the windows more visible. Fritted glass, which is printed with ink and contains tiny particles of ground-up glass, creates a frosted or slightly opaque appearance.
Gang's aim to "naturalize" skyscraper buildings, typically composed of straight lines, was just one aspect of their efforts. Catalan architect Antoni Gaudí once said, "There are no straight lines or sharp corners in nature." The world's tallest wooden tower is set to be built in Australia.
Bird-safe glass
The Aqua Tower features curved balconies that serve to soften the otherwise conventional hard edges of a typical skyscraper. These wave-like structures not only minimize wind shear and provide shade, but also contribute to the building's unique aesthetic. In addition, the fritted glass and reflective qualities help to reduce the sharpness of the glass edges, enhancing visibility, especially during the night.
The tower showcases how architectural elements selected to improve human lives can also be beneficial for other species. This concept was tackled by architect Joyce Hwang of Buffalo in her 2015 project No Crash Zone. Hwang temporarily applied patterns to the windows of the Sullivan Center in Chicago, not only to prevent birds from colliding with the glass, but also to enhance the material's visual appeal.
A laminate of dots applied to many of the windows at the L.L. Bean headquarters in Freeport, Maine.
Gregory Rec/Portland Press Herald/Getty Images
Hwang asserts that architects can continue to utilize glass in building design, but suggests incorporating graphic ornamentation to please both humans and wildlife. An example of a simple design solution is the use of bird-friendly film, which consists of dots applied to glass to help birds perceive windows as solid objects and reduce the risk of collision. This approach has been embraced by various buildings in New York City, such as Columbia University, a hotel, cemetery, mail facility, and ferry terminal.
Floating architecture isnt the future. Its already here
Lights out
The use of artificial light by humans poses a significant challenge when it comes to protecting birds. For example, in 2019, it was found that the annual Tribute in Light installation in New York City, which commemorates the 9/11 attacks, caused migratory birds to become disoriented and fatigued. The birds were attracted to the four-mile-high beams of light, causing them to deviate from their migratory paths and become trapped by the spectacle.
In 2020, it was decided to periodically turn off and then restart the lights so that disoriented birds can recover and continue their journey.
A study conducted in Chicago in 2021 showed that this principle has broader application: reducing the number of bird collisions by six to 11-fold by turning off half of the lights in larger buildings at night. There is currently a debate in New York about changing the law to prohibit nighttime illumination of unoccupied buildings, with many courtrooms, libraries, and public schools in the city already turning off their lights during bird migration season.
Philadelphia joined a national initiative to dim building lights during the spring and fall bird migrations.
The long-term impact of these changes on attitudes towards artificial light in cities remains uncertain. The 24/7 culture of cities has all but eliminated natural light and dark cycles, making nighttime illumination a constant feature. Even in the event of widespread power failures, such as those that occurred in New York City after Hurricane Sandy in October 2012, cities rarely experience total darkness.
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There are alternative methods for reducing the use of artificial light. Darkness plays a crucial role in the natural world, providing a means for animals and plants to rest and seek shelter. For migratory birds, darkness offers a secure environment and allows them to navigate using the light of the Moon and stars, as well as their sensitivity to the Earth's magnetic field during their long journeys.
Caring for migratory birds may also lead to a deeper appreciation of the night sky. By creating cities that are more bird-friendly at night, it could help residents to rediscover the beauty and wonder that these views evoke.
Paul Dobraszczyk is a lecturer in architecture at University College London (UCL).
Republished under a Creative Commons license from The Conversation.
