Over 1,000 birds lost their lives as they collided with a single building in Chicago on October 5th while migrating south to their wintering grounds.
This catastrophic event has highlighted the hazards that urban environments and light pollution pose to avian populations.
Volunteers are still recovering bird carcasses within a 1.5-mile radius of McCormick Place, the largest convention center in North America, which features extensive glass facades.
The collision occurred during a peak migration period when an estimated 1.5 million birds were in the airspace over Cook County, encompassing the Chicago metropolitan area, from late October 4th to early October 5th.
Among the casualties were Tennessee warblers, hermit thrushes, American woodcocks, and other songbird species.
The full extent of the impact on bird populations is expected to become apparent in the coming days as recovery efforts continue throughout downtown Chicago.
Buildings claim billions of bird lives annually, exaggerated by Chicago tragedy
Bird fatalities due to collisions with buildings often occur during peak migration seasons in spring and fall.
Challenging weather conditions such as opposing winds, rain, and fog can disorient birds during their journeys.
Additionally, light pollution from urban areas can attract and trap them amidst hazardous structures.
Bryan Lenz from the American Bird Conservancy emphasized that bird collisions with windows are a widespread issue, stating, “Anywhere you’ve got glass, you’re gonna have birds hitting the windows.”
Annually, collisions with buildings lead to the deaths of up to a billion birds. In the case of Chicago, the deceased and injured birds were likely en route from Canada to South and Central America.
Birds play crucial roles in ecosystems, providing essential services with economic and ecological value.
They aid in seed dispersal and contribute to forest regeneration, particularly in areas affected by wildfires.
Furthermore, birds help control insect populations, which can threaten human well-being and food systems, particularly as global temperatures rise.
Chicago is a city with significant light pollution, making it particularly hazardous for migrating birds.
One way to mitigate these fatalities is by turning off building lights. A study conducted at McCormick Place in 2021, the exact location as the recent bird fatalities, found that reducing building lighting by half can lead to a six to elevenfold decrease in collisions.
McCormick Place participates in the Lights Out Chicago program, encouraging buildings to dim or turn off lights at night when unoccupied voluntarily.
Additionally, incorporating visual markers like dots or patterns on window glass can help break up reflections and allow birds to perceive whether there is a safe passage through the glass.
While Chicago approved a bird-friendly design ordinance in 2020, it has yet to take effect.
In 2021, Illinois Governor JB Pritzker signed the Bird-Safe Buildings Act, which mandates bird-friendly design in state-owned buildings, showing a growing recognition of the need to protect migrating birds from urban hazards.
Source: The Guardian