Nearly 1,000 Migrating Birds Die After Colliding With Chicago Building

Hundreds of dead songbirds were found outside a Chicago convention center after a mass collision event.
The bird deaths were likely caused by the building's bright lights and glass windows, which can confuse and attract migrating birds at night.
Mass bird collision events like this are rare, but individual bird strikes are common in cities, causing hundreds of millions of deaths annually in the US.
Preventative measures like dimming lights, marking windows, and reducing lighting during migration can help mitigate bird collisions.
Avian experts and activists continue to warn that artificial lights and glass structures pose a significant threat to birds, especially during migration seasons.