More than a thousand migratory birds were killed in a single-building collision in Chicago overnight. Experts believe this was a result of the building's lack of "bird-friendly" features and the fatal mix of migration season and resilient weather.
Annette Prince, director of Chicago Bird Collision Monitors, told CNN that over 1,000 dead birds were retrieved by the Chicago Field Museum on Wednesday night and Thursday morning, October 4 and 5, after they had crashed into the McCormick Place Lakeside Center, a conference center situated on the coast of Lake Michigan.
Chicago Bird Collision Monitors volunteers found and removed another thousand dead birds from the central business district, according to Prince. She speculated that many more birds had flown away after hitting a structure, only to die from their wounds later. To witness so many dead birds was both overwhelming and terrible, she said.
Deadly Building Collisions
That night, a large number of birds were expected to begin their annual migration to the south for the upcoming winter. The birds had been holding back until they could catch a northerly or westerly breeze to help them on their way. On Wednesday, when the winds were favorable, several migratory birds took off simultaneously.
Foggy and low cloud situations, Prince said, might cause them to mistake lights and structures for one another. The birds were probably flying lower because of the clouds, putting them in closer proximity to the buildings. She said that McCormick Place is one of the first structures the birds see as they fly over Lake Michigan.
Collisions are also more likely to occur at buildings that keep their lights on throughout the night when most birds travel. Like a lighthouse, the lights serve as a major beacon for migrating birds.
Even during the day, she added, birds were still crashing into the McCormick Place Lakeside Center, proving how much big panes of transparent glass can disorient flying species. Birds will attempt to fly through a huge expanse of glass since they will not be able to tell that there is a barrier between them and the building.
Early Bird Migration
In a September report by the Chicago Tribune, Professor Michael Patrick Ward of the University of Illinois's Department of Natural Resources and Environmental Sciences claims that bird migration occurs twice a year, in the spring and autumn. According to Ward, fall migration begins about the middle of August and may go as late as the beginning of November.
The start of this year's bird migration was earlier than usual. He suggested this could be partly attributed to the early-summer wildfires in Canada. Fog may derail birds migrating hundreds of miles from Canada's northern woodlands to South America.
Over 300 bird species migrate along the Mississippi Flyway, which passes through Chicago. Birds feed all day to preserve energy for their nighttime journey. Skyscrapers, however, may be an obstruction.
