The most common reason birds fly into windows is because they don't see the glass. Some birds fly into windows because they are being chased by predators, while others will fly at the window because they see the reflection of what they think is a bird invading their territory.
Some birds will dash repeatedly at their reflections in windows. Such actions typically occur because the bird, usually a male, mistakenly perceives his reflection in the window as another bird. This behavior does not usually harm the bird.
On the other hand, when a bird strikes a window in free-flight, it does so with such velocity that the results are significantly more serious, with over half of all such incidents resulting in death. These strikes are most common during spring and fall migration.
You can make your windows safer for birds by following these steps:
Feeders and birdbaths should be located a safe distance from windows. If you want your feeders closer, move them within three feet of the window or put up a window feeder, so if the birds hit the window when fleeing the feeders, they will not have built up enough speed to harm themselves.
Window screens are a great deterrent but are not practical for many picture windows.
Decals, including cut-outs of raptors, and leaded glass decorations are only modestly successful in preventing window strikes.
Vertical exterior tape strips placed not more than 10 cm apart on windows are a good deterrent.
Interior vertical blinds with the slats half open will also cut down on some casualties.
Shade trees planted outside the window could cut down on some of the reflection and thus, the number of strikes.
All Wild Birds Unlimited logos are registered trademarks of Wild Birds Unlimited, Inc. Unauthorized use is prohibited. Images and artwork used are copyright Wild Birds Unlimited, Inc.