Spring arrived here today on the wings of huge, soft snow flakes but they are gone now leaving us wondering where the white went. Watching the snow fall this morning I noticed a mark on one of our windows that looks like a bird strike. Fortunately, no dead bird was beneath the window so we assume that bird survived the crash. Most don’t. As we’ve written before, astonishing numbers of birds die every year smashing into glass windows.
Our species has moved indoors, but we don’t want to lose our visual connection with the outdoors, so we build with glass. As a result, billions of birds are killed every year by hitting our windows. As far as the birds can tell, they are flying along, minding their own business, when suddenly the air crystallizes. All the bird sees is a reflection of sky. Some crash into windows of tall buildings during migration, but many die as the result of crashing into home windows. For birds, glass is just like a mirror reflecting atmosphere and birds can’t tell the difference. And, we can relate– who among us has not walked into a glass door?
We can do many things to help reduce the slaughter, some quite simple. For instance, don’t wash your windows. Birds can see the dirt and avoid the crash. And you can tell your friends and neighbors that you’re not a poor housekeeper, you’re saving lives.
A second simple remedy is put your bird feeders really close to the window. They should be within three inches of the window. If startled while feeding, the bird won’t be able to get to full speed before colliding with the glass. Anything further away allows them to get to full speed. A feeder six inches away from glass will result in serious injury or death.
Less effective, but still helpful, are window decals. Many are now made of material that is easily visible to birds but less so to humans. (Birds see a wider range of light than we do. That is why, for instance kestrels and owls are able to zero in on small mammals. They spot the tiny marks of dried urine, invisible to humans who can’t see those wavelengths. Experiments are in progress now with coatings for glass in skyscrapers that would be invisible to us but which birds would clearly see.) To be effective the decals need to be spaced leaving 2” horizontal gaps and 4” vertical gaps. You needs lots of them on a window to them to work.
Attaching streamers, prayer flags, or pieces of cloth that flutter in the breeze will help too. Even better, from the birds’ standpoint, is netting or screens. They are taut enough that birds bounce off the netting and not the glass. These screens come with mounting hardware and suction cups so installing them is easy and does no damage to your home. The netting used to cover fruit trees also will work. Your view will be degraded to some extent but not as badly as you might expect. You may have many window screens on your windows already and you likely don’t notice them when looking out.
You can also buy window film that looks like frosted or etched glass.
None of these solutions is perfect, but it is worth doing to help save birds, which already face so many other human-caused survival challenges. (When a bird does crash into one of your windows, about all you can do for it is put a box over the bird or gently place it in a shoebox and cover the shoebox. If the bird is going to survive, it will fly off when you release it. Give it an hour or so before removing the cover.)