David Willard has been searching for dead birds on the Chicago Lakefront Exhibition Center grounds for 40 years. On Thursday morning he found something terrible: hundreds of dead songbirds so thick they looked like a carpet.
Nearly 1,000 songbirds died the night after the crash McCormick Place Lakeside Center According to bird experts, this is the result of a deadly combination of prime migration conditions, rain and the lights and window walls of the low-rise exhibit hall.
“It was like a carpet of dead birds outside the windows there,” said Willard, a retired collections manager for the bird department at the Chicago Field Museum, where his duties included managing, preserving and cataloging the museum’s collection of 500,000 bird specimens as part of the bird strike search Migration research.
“On a normal night there would be zero to 15 (dead) birds. “It was just a shocking outlier from what we were experiencing,” Willard said. “In the 40 years we have been following events at McCormick, we have never seen anything of this magnitude.”
Researchers estimate that hundreds of millions of birds die from window strikes in the United States each year. Scientists from the Smithsonian Conservation Biology Institute and the US Fish and Wildlife Service published a study In 2014 the number was between 365 and 988 million birds per year.
Window strikes are a problem in almost every major US city. Birds do not see clear or reflective glass and do not understand that it creates a deadly barrier. When they see plants or bushes through windows or reflected in them, they run towards them and kill themselves in the process.
Birds that migrate at night, such as sparrows and warblers, rely on the stars for navigation. Bright lights from buildings both attract and confuse them, causing windows to break or birds to fly around the lights until they die of exhaustion – a phenomenon known as fatal light attraction. In 2017, for example, nearly 400 passerines became disoriented under the floodlights of a skyscraper in Galveston, Texas, and died in collisions with windows.
“Unfortunately, it’s really common,” said Matt Igleski, executive director of the Chicago Audubon Society. “We see this in pretty much every major city during spring and fall migration. That (window slamming at McCormick Place) was a very catastrophic individual event, but when you add it all up (across the country), it’s always like that.”
Conditions were ripe for a massive wave of southern songbird migrations over Chicago on Wednesday evening, said Stan Temple, a retired University of Wisconsin-Madison wildlife ecology professor and bird expert.
Small songbirds feed during the day and migrate at night to avoid air turbulence and predators. They were waiting for northerly winds to give them a boost southward, Temple said, but in September there were unusually warm southerly winds that kept the birds here in a holding pattern. On Wednesday evening, a front swept south, creating a tailwind, and thousands of birds took to the skies.
“There were all these birds that couldn’t wait to fly, but they were stopped by this strange September and October with well above normal temperatures,” Temple said. “They let this huge pack of birds take off.”
The birds flew south over Chicago and followed the shores of Lake Michigan – landing directly in a maze of lighted structures, Temple said.
The predawn rain forced the birds to move to lower elevations, where they encountered the lights at McCormick Place, Willard said. According to the Field Museum’s count, 964 birds died at the center. That’s about 700 more than have ever been found at the center in the last 40 years, Willard said. According to the Field Museum, members of 33 species died; Most of them were Palm and Yellow-rumped Warblers.
Window strikes and deadly light attraction are easily preventable, said Anna Pidgeon, an avian ecologist at the University of Wisconsin-Madison. Building managers could simply dim their lights, she said, and architects could design windows with markings in the glass that birds could easily spot. People can also put up fly screens, paint their windows, or put stickers on the glass.
New York City has made it a point to temporarily turn off the two beams of light that symbolize the World Trade Center during the annual September 11th memorial ceremony prevent birds from getting caught in the light shafts. The National Audubon Society launched a program in 1999 called Lights out, an attempt to encourage urban centers to turn off or dim lights during migration months. Nearly 50 U.S. and Canadian cities have joined the movement, including Toronto, New York, Boston, San Diego, Dallas and Miami.
Chicago also participates in the Lights Out program. The City Council passed an ordinance in 2020 requiring bird protection measures in new buildings, but has not yet implemented the requirements. The first buildings at McCormick Place were constructed in 1959.
Cynthia McCafferty, a spokeswoman for McCormick Place, said the exhibit hall participates in Lights Out and interior lights are turned off unless employees, customers or visitors require them. She added that the center maintains a 2.4-hectare bird sanctuary.
McCafferty said there was an event going on at the center all week, so the lights were on when the building was occupied but off when it wasn’t. She said she was unsure when the window smashes occurred or whether the center was occupied at the time.
“It’s a strange building,” Willard said of the exhibition center. “When it was built, people didn’t think about bird safety. They are still not present in most architectures. It is right on the lakeshore. There are many nights when it is lit. People describe the whole night of migration as part of a one-time thing… (but) this is still an unacceptable incursion by man and his architecture. Just terribly sad and dramatic.”