For forty years, David Willard has carefully walked around the Chicago waterfront exhibit center and recorded the bodies of birds that have died. In the morning of Thursday, the person in question made a disturbing discovery: a large number of dead sparrows covering the ground so thickly that it looked like a blanket.
About 1,000 songbirds died at night when they flew into the windows of the McCormick Place Lakeside Center. According to experts in birds, this terrible event was caused by a deadly mix of good flight conditions, rain, and the show hall’s bright interior and large windows.
“Just like a carpet of dead birds at the windows there,” Willard, who used to be the collections manager for the bird section at the Chicago Field Museum, said of the scene. Willard’s job at the museum was to oversee, care for, and organize the collection of 500,000 bird specimens. He was also responsible for looking for bird strikes to help with flight studies.
“A normal night would be zero to 15 (dead) birds. It was just kind of a shocking outlier to what we’ve experienced,” Willard said. “In 40 years of keeping track of what’s happening at McCormick, we’ve never seen anything remotely on that scale.”
According to figures from experts, a large number of birds die every year in the United States when they crash into windows. This number could reach hundreds of millions. In 2014, experts from the Smithsonian Conservation Biology Institute and the U.S. Fish and Wildlife Service did a study that said the annual death rate for birds was between 365 million and 988 million.
In almost all of the United States’ big towns, window hits are a common problem. Some bird species can’t see through clear or reflective glass, so they don’t realize that it could be a deadly obstacle. People who look at plants or trees through windows or their images are more likely to approach them and then do things that hurt themselves.
Some birds, like sparrows and warblers, are active at night and depend on the stars to help them find their way on their migration routes. Animals that live in cities are both attracted to and confused by the bright buildings that are usually found there. This effect, which is also known as “fatal light attraction,” happens when birds fly into windows or circle around lit buildings until they get too tired to keep going and die.
In 2017, an interesting event happened in Galveston, Texas: the floodlights of a building made a lot of people, about 400 in total, lose their way. As a result, these birds sadly died when they hit windows.
In 2017, an interesting event happened in Galveston, Texas: the floodlights of a building made a lot of people, about 400 in total, lose their way. As a result, these birds sadly died when they hit windows.
Stan Temple, an avian expert and former wildlife ecology professor from the University of Wisconsin–Madison, said that a big group of songbirds migrating south would pass over Chicago on Wednesday night.
Tiny sparrows fly at night to avoid being eaten or squished by planes, and they eat during the day. Temple says they were waiting for winds from the north to push them south, but in September, unusually warm winds from the south pushed birds to stay put around Chicago. A front moved south quickly on Wednesday night, making a breeze that made a lot of birds take to the air.
“You had all these birds that were just raring to go, but they’ve been held up with this weird September and October with temperatures way above normal,” Temple said. “You had this huge pack of birds take off.”
Temple says the birds flew south over Chicago, following the shore of Lake Michigan until they hit a group of lit-up buildings.
Willard says that when the birds went down to lower levels because of the rain before dawn, they saw that McCormick Place had lights on. It is said by the Field Museum that 964 birds died there. Willard said that was almost 700 more than had ever been found at the school in the previous 40 years. The Field Museum says that 33 species lost members; most of them were yellow-rumped and palm warblers.
Anna Pidgeon, a bird ecologist at the University of Wisconsin–Madison, says that deadly light draw and window hits can be avoided. She said that builders could make windows with symbols that were easy to read, and building managers could just turn off the lights. People can also paint their windows, put up screens, or use stickers to decorate the glass.
In order to keep birds out of the light shafts, New York City has started turning off the two light beams that represent the World Trade Center for a short time every year on September 11.
The National Audubon Society started the Lights Out campaign in 1999 to try to get cities to turn off or lower their lights during migration months. A lot of places in the US and Canada have joined the movement, such as New York, Boston, San Diego, Dallas, and Miami.
Cities all over the world take part in Lights Out. In 2020, the city council passed a law that new buildings must take bird safety measures. The rules have not yet been put into action, though. The first buildings at McCormick Place were put up in 1959.
Cynthia McCafferty, a spokeswoman for McCormick Place, said that the exhibition hall takes part in Lights Out and turns off the lights inside when it’s not being used by staff, clients, or guests. She also said that the center takes care of a six-acre bird refuge.
McCafferty says that the center has been holding an event all week, so the lights were on when the building was being used and off when it wasn’t. She said she didn’t know when the window hits happened or if anyone was in the building at the time.
“It’s an odd building,” Willard said of the exhibition center. “When it was built, people weren’t thinking about bird safety. They still aren’t in most architecture. It’s right on the lakefront. There are many nights when it’s lit up. People are describing the whole night of migration as part of a once-in-a-lifetime thing … (but) this still is an unacceptable intrusion by humans and their architecture. Just terribly sad and dramatic.”