There are few things like the sound of a bird striking your home or office window to grab your attention. But what is merely startling to you can kill birds.
Bird-window collisions are common and often fatal to wild birds in the U.S., according to Nicholas Lund, advocacy and outreach manager at Maine Audubon. More than one million birds a day die in this country after striking windows. Luckily, there are steps you can take to prevent it from happening in the first place.
“It’s a huge problem,” Lund said. “It’s one of the lead causes of death right up there with habitat loss, climate change and domestic cat predation.”
The U.S. Fish and Wildlife Service estimates between 388 million and 988 million birds die each year after flying into window glass.
“Glass is not natural, and it does not make sense to birds,” Lund said. “So it tricks them.”
Window glass reflects whatever is around or in front of it. From the bird’s perspective, it looks like a clear and open path. Because birds don’t see the actual glass, they end up flying into it head first.
Smaller songbirds seem to be the most at risk.
“These are the smaller birds that are prey for bigger things,” Lund said. “They have evolved to have eyes on the sides of their head to see predators, so they can’t see directly in front of them and do not have great depth perception.”
The cause of death for these birds is usually blunt force trauma.
“These are birds that weigh not much more than a nickel,” he said. “They are not bracing themselves, and they hit face-first and will usually die from a broken neck and internal trauma.”
If a bird does hit your window and is not killed outright, it’s often too stunned to fly away, so it becomes an easy meal for a wild predator or outdoor cat. Lund said steps can be taken to give the bird a fighting chance to survive, albeit a slim one.
“If you feel comfortable doing so, you can move the injured bird to under a bush or somewhere it’s out of sight,” Lund said. “Or you can place it in a cardboard box and see if it recovers enough to fly off.”
Calling a wildlife rehabilitator is another option, though Lund said there is not much they can do.
The best thing for the birds, Lund said, is to prevent them from crashing into a window in the first place.
“The good news is there are tons of ways to prevent it from happening,” Lund said. “It’s a matter of giving birds an indication that there is a window there, not just a reflection.”
The best option is placing a simple insect screen over the outside of the windows, Lund said. Not only does it cut the reflection on the window but if a bird does run into it, the bird will more than likely bounce off uninjured.
Any sort of decal or sticker placed on the window will break up the reflection. You can also hang cords in front of the window to serve as warnings. Special paint made just for painting on glass is another good strategy and you can draw designs or murals on your glass.
There are a number of recommended commercial products to help birds avoid flying into glass listed by The American Bird Conservancy.
Lund works with BirdSafe Maine, a collaboration among Maine Audubon, The Portland Society for Architecture and the University of Southern Maine to address the problem of bird window strikes in Maine.
“It’s been going for three years,” Lund said. “We are making good progress.”
The group is currently supporting a bill in the Maine Legislature that would help reduce bird-window deaths.
Last week Lund testified at the public hearing for LD 670, which is an act to protect birds and wildlife in construction and maintenance of public buildings. It would require the state to develop guidelines that protect birds and other wildlife when planning new construction or repairs to any public buildings.
“When you think about the landscape birds fly through, we have changed it so much in the last 100 years,” Lund said. “Now they are forced to go around our buildings with windows.”
BirdSafe Maine maintains an active database of bird-window strikes in the state and asks the public to report any they witness, according to Lund. You can report a bird strike by taking a photo of the bird and forwarding it and the location to birdstrike@maineaudubon.org.