Guelph, Ontario

Reducing Window Collisions

Because there is no single, universal answer to eliminating window collisions, there exist several methods and/or products to reduce the number of birds hitting your window.  Remember, one thing that works in one location may not work in another location. Sometimes it takes a bit of trial and error to find what works for your situation.


Here is a list of the most popular ways to discourage window collisions:


1- Decals/window stickers

2- BirdScreen/netting

3- CollidEscape

4- Hi-liter

5- Mono-filament fishing line

6- Moving the feeders either very close or very far away


1. Decals.

One of the solutions that is most inexpensive and easiest to install. Any object, placed on the exterior of the glass, will help to break up the reflection. These work best for smaller sized windows, and you need more on each window as the pane size increases.


2. BirdScreen.

This is a relatively new product that you can buy online, and is relatively easy to install. It is just a black screen that comes with hooks and suction cups so that it hangs several centimetres away from the pane. Not only does it let the birds know that there is something solid there, but also if a bird does fly into it, it cushions the blow. Some people have also had success making their own kind of “screen” using garden netting. See References below to follow the link to see photos and read more about the BirdScreen.


3. CollidEscape.

This is a “screen” that you stick onto the window similar to a decal. But it is one-way, which means you can still see through your window, but from the outside, it appears solid and opaque. You can also buy this online through the FLAP website. See References below to click the link to the CollidEscape page.


4. Hi-liter.

Famous birder David Sibley experimented at his home with drawing a grid on his windows with hi-liter. The theory is that birds can see the UV light that is reflected by the hi-liter. However, there are still some mixed results as to whether most birds see the UV, and this method will not be as effective on a cloudy day.


5. Mono-filament.

David Sibley also had success with hanging a grid of mono-filament fishing line in front of his windows. This is inexpensive, but not very easy to install. This solution, as well as the Hi-Liter solution above, can be found in an article that David Sibley wrote in the recent Birder’s World; see link in References below. 


6. Moving your feeders.

There is always the option of moving your birdfeeders: either very close to the window - less than 3 feet - or very far away, even up to 30 feet. If the feeder is very close to the window, the bird does not usually pick up enough speed to hurt itself if it does end up hitting the window. If the feeder is far enough away, the birds usually fly another route of escape before they get near to the window.






BirdScreen Company.


Daniel Klem, 2006. “Glass: A Deadly Conservation Issue for Birds.” Bird Observer. Vol 34:2 p. 73 - 81. 

                You can find this article, as well as links to many other good resources, online at the BirdScreen website:   


David Sibley, 2008.  “Window Pain.” Birder’s World.Vol 22:6 p.35-37.

                This article is posted online at the BirdScreen Articles webpage.

                You can also visit David’s blog online, where he has posted all of his at-home research on reducing window collisions, as well as comments/suggestions from other readers:


FLAP (Fatal Light Awareness Program). 

               To see what the CollidEscape screen looks like, and to read more, click on "Prevent Window Kills" next to the Rose-breasted Grosbeak.