Almost 1,000 migrating birds die Thursday in Chicago after crashing into McCormick Place Lakeside Center, a 40-year record

At least 960 migrating birds, the highest number on record, died Thursday in “massive carnage” at McCormick Place Lakeside Center, according to David Willard, a retired bird division collections manager at the Field Museum.

Birds were crashing into windows even as monitors collected the casualties, Willard said.

“It was just discouraging as can be,” said Willard. “You’re looking at a rose-breasted grosbeak that, if it hadn’t hit a Chicago window, would have made it to the Andes of Peru.”

Willard blamed the worst day in 40 years of monitoring on an array of factors, including weather patterns, badly timed rain and lit windows at Lakeside Center.

First, there was a stretch of time with few winds out of the north, which left a lot of birds backed up and ready to migrate: “Sometimes, it’s like ‘now or never,’ and they go,” Willard said.

Then, when the flight began, it was huge. One local birder who was out Thursday morning told Willard that he hadn’t seen anything equal to it in 40 years. Another birder said he saw 100,000 birds move past Promontory Point in Hyde Park. Wrigleyville resident Nathan Goldberg told the Tribune he saw roughly 172,000 birds overhead in under four hours.

Rains early in the morning may have driven the waves of birds lower to the ground — and closer to danger.

And then there were the windows at Lakeside Center. It’s estimated that a billion birds die crashing into windows in the United States every year, Willard said.

Thursday was also a record day for Chicago Bird Collision Monitors, which found about 450 dead birds and rescued 300 injured birds, according to Director Annette Prince.

“We’re talking about irreplaceable birds that are a critical part of a healthy environment,” Prince said. “They’re already declining significantly and for them to die needlessly at the feet of all these buildings as they did today — it’s a tragedy.”

There are fixes for bird-building collisions, Willard said, including bird-friendly windows, but the issue tends to attract more attention than action. In Chicago, a City Council ordinance requiring bird safety measures in many new buildings passed in 2020, according to Prince, but has not yet been implemented.

The dead birds at Lakeside Center were photographed and taken to the Field Museum, where they will be prepared as scientific specimens and used in studies.

Many were palm warblers and yellow-rumped warblers, colorful little songbirds that are common in Chicagoland in spring and fall.

Willard said that monitors at Lakeside Center generally find zero to 15 dead birds on an average day.

In the worst days of the 40-year monitoring project, 100 to 200 birds were found dead.

The signs of collision lingered in the window of a River West cafe Friday morning: A single, smudged feather was stuck to the glass.

Jennifer E. Bell had just finished a morning shift searching for birds dead and alive when she walked into the cafe. She went outside to examine the lingering feather as she waited for her coffee to brew.

When the Chicago Bird Collision Monitor volunteer came back in, she produced from her refrigerator bag a ziplock baggie to attach a label. It held a small, green-tinted ovenbird. She had already turned in her finds from the day — a living woodcock with a bleeding beak, four more surviving warblers and a half-dozen dead birds — but found this last one on her walk home.

“You see it’s got the spots, and then it’s got two lines on his head, and then it’s got a little rusty color,” she said.

Bell put the dead bird back in the bag. She didn’t want to freak out any customers, she said.

The adult education professor takes on bird monitoring shifts in her free time. She gets up at 4:45 a.m. to start her hunt for the fallen. Waves of birds typically arrive in Chicago just as the sun rises, she said.

She saw calls for help amid Thursday’s onslaught, she said. After teaching class, she responded to a hotline report of a bird down near a River West school. It was a kingfisher.

“He was alive,” Bell said.

She put the bird in a Trader Joe’s paper bag with paper towels at the bottom. She left the bag in her bathroom overnight — the perfect dark, quiet place for the bird to recover — and dropped it off to be taken to the Willowbrook Wildlife Center in west suburban Glen Ellyn on Friday morning.

The center receives, rehabilitates and releases many injured birds, she said. Some might have a concussion, others brain swelling or broken wings. Paper bags containing avian survivors crowded space in a photo that the center posted on Facebook to show Thursday’s toll.

“It was a truly devastating day,” the wildlife center wrote in the post.

Sometimes, Bell keeps dead birds in her freezer. The ones lucky to be alive might sit in bags on her bathroom counter. Her son and boyfriend have been understanding about the space that her lifesaving hobby takes up in their apartment.

Bell was trained to save birds in March, at the same time her mother was living with her and undergoing cancer treatment. Her mom died, she said, and the experiences have since intertwined. Now, as she makes her morning rounds searching for birds, she hears from the construction workers and building managers who know to keep an eye out for her.

“When I’m taking time to explore the city, I’m doing it for a purpose,” she said.

As she left the cafe and headed home, Bell kept her eyes peeled. Suddenly, a lump appeared ahead on the Milwaukee Avenue sidewalk.

“That could be a bird right there,” she said.

She walked closer.

“Yep.”

The tiny creature was lying on its side. Its legs hovered unnaturally in the air. It didn’t look good.

Nonetheless, Bell, who has been trained to always assume the birds she finds are living, took out her white net. She placed the net over the warbler and touched it. The feel confirmed what she already knew.

“He’s dead,” she said.

nschoenberg@chicagotribune.com

jsheridan@chicagotribune.com