On the morning of Oct. 17, bird collision monitor Allison Sloan arrived at Northwestern’s Kellogg Global Hub. What followed was unlike her usual morning patrol.
“I would pick up three, and then run around the corner and pick up a couple more, and then come back, and there would be three more,” Sloan said. “And they were hitting on the upper levels where we couldn’t reach them.”
Sloan said volunteers collected 35 injured birds and 12 dead birds at Kellogg that morning.
The incident raised a question: Why did so many birds collide with the building at one time?
The Kellogg Global Hub opened in 2017, overlooking Lake Michigan. Its curved glass exterior is a defining feature of the building. But conservationists say the same architecture that gives visitors
sweeping views of the lake creates an obstacle that migrating birds can’t always recognize.
Northwestern is a particularly precarious spot because not only does it have beautiful trees and foliage and native plant habitat that attracts birds, but it also has a lot of glass buildings,” said Holly Greenberg, an Evanston bird conservation advocate and the founder of Bird Collisions in the Anthropocene, a community art project documenting the toll of window collisions. “But also, more importantly, it lies in a very important migratory path that millions of birds use for millennia.”
Sloan has monitored Northwestern’s buildings for years. She said collisions have decreased due to bird-safe window treatments on buildings like Mudd Library and the Francis Searle Building.
At Kellogg, however, the problem persists despite efforts to make the building safer. Northwestern has installed bird-safe dot patterns on portions of its windows, but volunteers say birds continue to collide
with both treated and untreated sections.
“A lot of the smaller ones, especially, were just trying to fly between the dots,” Sloan said. “It’s like it’s still so reflective that it draws them in because they think they’re about to land on a tree or just keep flying
towards the sky.”
In a statement from Northwestern Media Relations, Northwestern said that the university has worked for over a decade to reduce bird collisions. It pointed to window film on several buildings, including newer film installed on parts of Kellogg in the past year.
The university also said it has guidelines for turning off lights and lowering shades during migration periods. It attributed the recent collision event to a windstorm.
But Sloan, who was there that morning, said the weather doesn’t explain why the birds hit the windows.
“They were here because the winds had changed to the north the night before,” she said. “But when we were there, it was completely calm, and there were just a lot of birds in the area, and they were all aiming
for the mirrored windows like that.”
Advocates say they are appreciative of the steps Northwestern has taken to protect birds. Still, they are asking for more extensive protections.
Sloan said the university could expand closely spaced window patterns to Kellogg’s upper floors and replace some glass railings with metal ones.
At Kellogg, the problem isn’t just the glass. Greenberg said the building’s coves and recessed areas can also trap birds that struggle to find their way out.
The issue extends beyond Northwestern. Glass buildings and residential windows pose risks to birds in other parts of the Chicagoland area and across the country.
Leslie Shad, an environmental advocate who helped push for Evanston’s bird-friendly ordinance, said the issue reflects a larger problem in current architecture.
“It just seems really uncreative that people can’t figure out a way to have a lighter touch on the environment,” she said.
The ordinance requires bird-friendly design in new construction, but doesn’t require existing buildings to be changed.
Shad said she wants Northwestern to work directly with local monitors who have spent years identifying the most dangerous spots.
“I wish they would actually engage in discussion with us so that we can actually say, ‘Look, first thing you do, fix these five windows,’” she said.
But preventing collisions isn’t only the responsibility of universities or developers. Greenberg said homeowners can also make their windows safer, using exterior dot patterns, screens or even drawings that break up reflections. Turning off unnecessary nighttime lights during migration can help, too.
For Greenberg, the issue extends beyond one building. Bird Collisions in the Anthropocene invites people to create replicas of more than 10,000 birds recorded in a Chicago collision dataset from 2023.
“We do not want to live on a planet where there are no birds,” Greenberg said. “That would be so sad and absolutely unnecessary.”
For Greenberg, that’s what makes these deaths so frustrating: The solutions already exist.
“I would say that Northwestern, as an institution of higher education, really needs to set the right example to their students, for their alumni, and to the world that they are a leader in protecting wildlife,” she said.
The Oct. 17 collision event may have lasted only a morning. But for volunteers who return to Northwestern’s campus throughout migration season, the problem is ongoing.
And as migrating birds continue to pass along Lake Michigan, advocates say the question isn’t whether collisions can be prevented, but whether more will be done to prevent them.
