This past week I was speaking to my parents on the phone and heard a commotion in the background. Apparently, a bird had struck the window and was in a daze. My parents explained that this happens quite often and scares them as well as their parrot who let out the loud shriek I heard when the impact occurred. The mourning dove that struck the window was stunned for a few minutes but eventually flew away. I mentioned this to a friend at work, and he said the same thing happens at his home and that there is usually a bird fatality every few months. So why do birds do this and what can be done?
As I did some research, I discovered that birds fly into windows for a few reasons. During the day, birds may see a reflection of the sky or trees and think that they have a clear path. For a bird, the reflected landscape can cause confusion and ultimately deadly window strikes. Even if a bird is stunned and eventually flies away, they may still die due to internal bleeding or bruising, especially bruising of the brain.
During mating season, birds may also fly into windows if they see their own reflection. These birds attack the window as a territorial display. This type of activity, however, is not typically a threat to the bird’s survival.
The last example occurs at night. For reasons unknown, nocturnal migrants are said to be lured in by the lights and may collide with other birds, lighted windows, or structures. This issue is especially prevalent in foggy or low-ceiling conditions.
One of the best ways to deter birds and ensure that they recognize a window as a barrier versus a clear path is to apply paint, tape, decals, stickers, or other adhesives to the outside of your window to break up the reflection and transparency. Whether using tempera paint or adhesive strips, make sure the vertical markings are no further than four inches apart, and if applying horizontal markings, one to two inches apart. This ensures a space that the bird would not be able to fly through and therefore recognize as a barrier in their path.
Screens or netting may also be effective if placed on the outside of the window as well as shutters, awnings, and anything that will obscure the reflection. Interior vertical blinds that are set with the slats at least halfway closed have also helped in some cases. Lastly, there are also companies that have created a transparent one-way film that makes your windows appear opaque from the outside but will still allow you to see out while you are inside.
If you’ve heard the thud of a window strike before, I hope you take a moment to consider ways to alleviate this issue and protect your winged visitors. We can all do our part to ensure an environment suitable for ourselves and our feathered friends.