At least 1,000 birds were killed in one day in early October, when they collided with a single Chicago building, McCormick Place Lakeside Center – the largest convention centre in North

America. A paradigm of architectural modernism, the Lakeside Centre was built in stages from 1960 to 2017, and is a steel, concrete and glass behemoth. Although not particularly tall by

contemporary standards, the building’s almost unbroken glass facade presents a problem for birds, most notably at night when the brilliantly lit interiors cause them to become confused. The

thousand killed that day were a small proportion of the millions of migratory birds that were moving southwards across the continent to their wintering grounds – a journey undertaken twice

2003. According to their records, this was the largest number of dead birds recorded in the grounds of one building over a single day. One way to prevent bird strikes is to pay more

attention to the design of glass buildings in cities. Chicago set an example for this in 2009, when US architect Jeanne Gang’s Aqua Tower was completed. Its wave-like facade and fritted

glass were in part designed to stop birds flying into the building’s windows. Fritted glass is printed with ink and contains ultra-small particles of ground-up glass, giving it a frosted or

otherwise slightly opaque appearance. This was just one aspect of Gang’s effort to “naturalise” the skyscraper – buildings that are typically composed of straight lines on account of their

steel or concrete frames. As the Catalan architect Antoni Gaudí once quipped: “There are no straight lines or sharp corners in nature.” BIRD-SAFE GLASS The Aqua Tower has curved balconies to

soften the hard edges of what is an otherwise conventional skyscraper. The wave-like rippling effect also serves to minimise wind shear and create shade. In tandem with the fritted glass,

the reflective qualities and hard edges of the glass are dampened, helping to prevent confusion, particularly at night. The tower demonstrates how architectural features usually chosen to

enhance human lives can also benefit other organisms. This challenge was taken up by Buffalo-based architect Joyce Hwang in her project No Crash Zone from 2015. Hwang temporarily applied

patterns to the windows of the Sullivan Center in Chicago, ostensibly to deter birds from flying into the glass, but also to add aesthetic interest to the material itself. Hwang has argued

that architects can still use glass in buildings – but with a little imagination, they can incorporate graphic ornamentation that will please us as well as other creatures (or maybe just not

distract them). More easily applied design solutions include bird-friendly film: a laminate of dots applied to glass to help birds see windows as objects rather than transparent, which

minimises the risk of collision. This feature has been adopted by Columbia University in New York and several other buildings in the city, including a hotel, cemetery, mail facility and

ferry terminal. LIGHTS OUT The way humans make use of artificial light, it seems, is the more intractable problem when it comes to caring for birds. In 2019, it was discovered that the

annual Tribute in Light installation, held in New York City every year to mark the anniversary of the 9/11 attacks, caused migratory birds to become disorientated and exhausted. The birds

are drawn to the four-mile high beams of light, veering off their migratory routes and becoming trapped by the spectacle. In 2020, the decision was made to periodically switch off the lights

and then restart them so that, even if the birds become disorientated, they can recover and continue on their way. A 2021 study carried out in Chicago demonstrated the wider application of

this principle: by shutting off half the lights in larger buildings at night, bird collisions can be reduced by anything from six- to 11-fold. At the time of writing, a change in the law is

being debated in New York to prohibit nighttime illumination of unoccupied buildings. Many courtrooms, libraries and public schools in the city already turn off their lights during the bird

migration season. Whether these changes can spur a wider transformation of attitudes towards artificial light in cities is uncertain. After all, nighttime illumination is bound up with the

24/7 culture of cities, which has seen the natural cycles of light and dark long since banished. Today, the illuminated city only goes dark in extreme circumstances, like the widespread

power failures across New York City that followed Hurricane Sandy in October 2012. Yet people could choose other ways to use less artificial light. Darkness is a vital part of nature. It is

the means by which animals, and plants, rest and take cover. For migratory birds, darkness is a safe place; it also allows them to perceive the world as they need to, with the light of the

Moon and stars (and their sensitivity to the Earth’s magnetic field) guiding their long journeys. Care for migratory birds could also yield a greater appreciation of dark skies. Making

nighttime cities more bird-friendly might help human residents reconnect with the beauty and awe that these vistas inspire. ------------------------- _DON’T HAVE TIME TO READ ABOUT CLIMATE

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