Recently, I was sitting in a meeting at a conference center that had two walls of windows. I heard a “thunk” against one of the windows, and I immediately knew what caused it. I got up to see if the victim survived. Sitting on the windowsill was a dazed little bird. I felt bad, knowing that the building we were located in was the visitor center of a nature reserve, but there were no bird collision avoidance measures taken.
In fact, bird collisions with windows are all too common. It is very difficult to estimate how many birds are killed, and how many more injured, from windows. Some come flying full speed into glass, thinking they can fly unimpeded to a location beyond it; others attack their own reflection over and over until they cause enough brain damage to themselves to be fatal. The numbers of dead birds is impossible to accurately estimate-from hundreds of millions to a billion birds every year in North America alone. Some birds are able to recover fully and fly away. Some birds die instantly on impact. There are an unknown number that start to recover, fly away and end up dying from their injuries in another location.
I work in the DNR Service Center on Sutliff Avenue. Last summer, the customer service staff started pointing out the birds that were getting injured or killed on almost a daily basis. One bird survived a collision with the window, but as it sat trying to recover, a small raptor (a meat-eating hawk or falcon) picked it up and flew away with it. The front doors and massive wall of windows around them were all highly reflective, mirrored glass. My recommendation was that we put something on the windows in an attempt to reduce the number of birds being injured and killed by our office. I ordered and installed two different kinds of bird deflectors-kestrel silhouettes in the upper windows, and American Bird Conservancy bird tape on the lower windows and doors. The bird collisions not only slowed down, they stopped completely.
It is my hope that homeowners, businesses and building owners who see birds dying from window collisions at their facility will consider implementing similar avoidance measures. If you haven’t seen the bird collision avoidance display, come by the DNR office and take a look. We have a write-up available at the counter explaining what we put up, where we ordered it from, and how much it costs. In fact, one of the criteria for Rhinelander to become a Bird City is to make window collision avoidance information available to homeowners and businesses.
At home, you may not need to pay for materials or take drastic measures. There are some simple steps you can take. If you have bird feeders out, move them closer to the window. Studies have shown that having feeders within 2 to 3 feet of the window will reduce collisions. If you do not have feeders, try picking up a suction cup feeder and attaching it to the window; not only will you protect birds, but you will feed and attract them. You can close curtains, partially close mini-blinds, or hang up pictures or decals on your windows to warn birds as well. If a window has a lot of green plants next to it, that could attract birds as well; consider moving them back just a bit. Come to the DNR office and pick up a coloring sheet of a kestrel. Your kids or grandkids can color it, cut it out and tape it to the window. The birds will not see this as a real predator, but as an object they cannot fly through. Take a few minutes to consider what minor changes you can make to reduce or eliminate bird collisions at your home or office. Even minor changes you make can make a big difference to the birds.
Jeremy Holtz is a wildlife biologist with the Wisconsin DNR and writes a weekly column in the Star Journal. To contact him, call (715) 365-8999.