Birds are crashing into downtown Nashville buildings. Treating windows could help.

When birds crash into windows, glass rattles and bones break. 

Glass kills as many as 1 billion to 5 billion birds every year in the U.S. Nearly all windows act like mirrors, so, for birds, glass appears like a continuation of the surrounding world instead of a blockade. 

Nashville has been no exception, but that could change soon: This month, the city proposed new guidelines for downtown developers to add special glazing to windows to reduce collisions.

“Design façades with attention to light reflectivity, glare and bird-friendly glazing when possible,” reads a city draft for design goals, a document that provides a broad plan for making downtown expansion more ecological.

But the guidelines are not enforceable codes. 

Bird advocates have previously asked the city to codify protections. Last year, Nashville joined a program called the Urban Bird Treaty to conserve urban habitat for birds and reduce hazards — amidst a controversy over a roost of purple martins in downtown that ended with habitat removal. The treaty’s agenda includes forming a working group to pass a city ordinance that requires new building construction to follow bird-safe design, construction and operation guidelines.

New York City passed such a law in 2020 that requires all new construction, plus buildings whose exterior glazing is undergoing alteration, to use bird-friendly glass on floors up to 75 feet high.

Caroline Eggers WPLN News

Bird advocates recommend adding treatments to windows across from bird feeders to reduce collisions.

The American Bird Conservancy offers a guide for developers to create bird-friendly buildings, and the community group Bird Safe Nashville has recommendations for homeowners and renters to upgrade their windows with simple treatments like netting or film.

Bird Safe Nashville also advocates for residents and businesses to turn out unnecessary lights at night during spring and fall migrations.