One Chicago Building Killed At Least 1,000 Birds In A Single Day

At least 1,000 birds have died from colliding into a single building in Chicago, USA on Thursday,  as they migrated south to their wintering grounds. 

 

Volunteers are still recovering bird carcasses within 1.5 miles of McCormick Place, the largest convention center in North America, which is largely covered with glass.

 

“It’s the tip of an iceberg but it’s it’s a huge, huge amount of birds we found both dead and injured”, said Annette Prince (right), director of Chicago Bird Collision Monitors, adding that this was the highest number of bird strikes that the group recorded from the grounds of one building in a single day. 

 

From late Wednesday, October 04, through early Thursday, October 05, a peak estimate of 1.5 million birds were in the air over Cook county, home to the Chicago metropolitan area. Carcasses of Tennessee warblers (Scientific name: Leiothlypis peregrina), hermit thrush (Scientific name: Catharus guttatus), American woodcocks (Scientific name: Scolopax minor) and other varieties of songbirds were recovered.

 

“Not every bird that hits the window is going to leave behind a body”, said Brendon Samuels, who researches bird window collisions at Canada's University of Western Ontario. He noted that the true extent of affected birds will unravel over a couple of days as people continue to pick up birds around downtown Chicago. 

 

“In fact, we often see birds collide with glass and they continue flying some distance away, seriously injured in ways that ultimately they won’t survive past a few hours”, Samuels added. 

 

Birds dying in large numbers in a small geographic area tends to occur during peak migration periods in spring and fall. Weather conditions like opposing wind, rain and fog can make it difficult for birds to orientate themselves, in addition to light pollution from cities that can draw them in and trap them among deadly structures. 

 

“Anywhere you’ve got glass, you’re gonna have birds hitting the windows”, said Bryan Lenz at the American Bird Conservancy. Annually, up to a billion birds die due to collisions, and in the case of Chicago, the dead and injured birds were most likely flying from Canada en route to South and Central America.

 

Everywhere birds visit, they perform essential ecosystem services that have economic value and are necessary for the functioning of ecosystems. Following major wildfires like those in Canada, birds that return to burned areas can disperse seeds and aid forest landscape regeneration. Global increases in temperatures contribute to the increase in insect populations, and birds that feed on them can help curb the issues that pose a threat for humans and food systems. 

 

And most unfortunately, of all cities in the US, Chicago’s light pollution poses the greatest risk for migrating birds.