Almost a thousand birds died after colliding with the windows of the Chicago Convention Center

Nearly 1,000 migratory songbirds died in the early hours of Thursday to Friday after colliding with windows at a convention center in Chicago, US.

Bird experts say the incident is the result of ideal migration conditions, rain, poor lighting at the convention center – McCormick Place Lakeside Center – and walls of windows, the Associated Press (AP) reports.

David Willard has been checking the Chicago lakefront fairgrounds for dead birds for 40 years, but on Thursday morning he was shocked by what he saw: hundreds of dead songbirds.

“It was like a carpet of dead birds in the windows,” said Willard, former director of the Chicago Field Museum’s bird department, where his responsibilities included managing, preserving and cataloging the museum’s collection of 500,000 bird specimens.

“On a normal night there would be zero to 15 birds. [mortas]. It was kind of a shocking exception to what we were used to. In 40 years of watching what’s happening in McCormick, we’ve never even remotely seen anything on this scale,” he said.

Scientists estimate that hundreds of millions of birds die every year in the United States due to broken windows.

In a 2014 study, scientists from the Smithsonian Conservation Biology Institute and the U.S. Fish and Wildlife Service estimated the number to range from 365 to 988 million birds per year.

Window strikes are a problem in virtually every major city in the United States because birds cannot see clear or reflective glass and do not recognize that it is a lethal barrier.

When they see plants or bushes through windows or are reflected in them, they move towards them, creating collisions that lead to the death of birds.

Birds that migrate at night, such as sparrows and warblers, navigate by the stars. Bright building lights attract and confuse them, causing birds to crash into windows or fly around the lights until they die of exhaustion.

“Unfortunately, this is very common. We see this in almost every major city during the spring and fall migration. Such situation [em Chicago] it was a very catastrophic single event, but when you add it all up [em todo o país]it always is,” said Matt Igleski, executive director of the Chicago Audubon Society, an association that protects birds.