Minor Window Modifications Can Reduce Wild Bird Deaths, Biologist Says

Migratory bird populations across the United States are rapidly declining, in large part due to human activity. Light pollution from populated areas can disrupt bird migration patterns, attracting them toward towns and cities where they are more likely to collide with translucent windows.

But biologists say residents and business owners can take small steps to help prevent bird collision deaths. That includes Richard Novak, a Pennsylvania-based endangered species biologist for the U.S. Fish and Wildlife Service (USFWS).

Novak visited the USFWS National Conservation Training Center (NCTC) in Shepherdstown on July 31 to deliver a lecture on making windows safer for migratory birds. The NCTC hosts a recurring lecture series where conservationists speak to members of the public about environmental issues.

For starters, Novak said residents can place opaque stickers or film atop the windows on their home or business. Without significantly disrupting visibility, Novak said these added protections make it more obvious to birds that a window lies ahead — not the expanse of sky or wilderness they might see in its reflection.

“The DIY ones are pretty cheap and easy to implement,” Novak said. “It’s important to do this. Really, every square foot of glass we can treat is protecting birds. Every square foot matters.”

A common misconception is that tall, glass-paned buildings like skyscrapers cause most collisions, Novak said. In fact, most collisions occur in more sparsely populated areas, where buildings are more spread out and more often connected to habitat areas.

Novak said spacing of stickers or window coverings is important too, because their density can signal to passing birds they are unable to fit through the barriers they see in the windowpane.

“Birds are very nimble flyers. They have a very good sense of what they can and cannot fit through,” he said. The goal “is to make [windows] look too complex [so] that they won’t try to fit through. Breaking up the reflections and breaking up those pass-through spaces to create a solid barrier is really important.”

All in all, this might seem like a small step toward change; Novak said that likely one billion birds or more die from window collisions each year, the second leading cause of bird mortality following attacks from feral or outdoor cats.

Still, Novak said residents can expand the impact of their efforts to reduce window collisions by spreading the word in their local communities.

Outreach can be a major step toward meaningful intervention, because it familiarizes people with the issue of window collisions and also helps them understand methods of intervention, he said.

“There’s many million square feet of glass in the United States. Say your home gets three or four bird collisions a year,” he said. “That adds up.”

To watch biologist Richard Novak’s full lecture at the National Conservation Training Center, visit the U.S. Fish and Wildlife Service YouTube page.