Promising new window film may prevent bird collisions

The most recent research by Dr. Daniel Klem, who has been studying the problem of bird/window collisions since the 1990s, has just been published in the June 2009 Wilson Bulletin. It is available, along with lots of other bird/window resources, at his website here.

Klem tested the effectiveness of various window treatments confirming, for example, that single decals on a window are not effective at preventing bird collisions, and that the non-reflective Collidescape film is nearly 100% effective at preventing collisions. Several different UV-absorbing films were tested with small to moderate success.

Beginning in 2007 Klem tested a new film developed in collaboration with Dr. Tony Port, a chemist at CPFilms. This film has vertical strips that reflect UV wavelengths alternating with vertical stripes that absorb UV wavelengths. The UV reflection and the alternating pattern seems to be very effective at deterring birds – only a few birds collided with the windows treated with this film, and none of those collisions were fatal. The real promise of this film lies in the fact that it appears clear to humans, and should be relatively easy to apply to existing windows!

Hopefully the company, CPFilms, can be convinced that there is a market for this window film, and start producing it commercially. I can think of dozens of windows that I would put it on.

Klem, Daniel, Jr. 2009. Preventing Bird-Window Collisions. The Wilson Journal of Ornithology 121:314 –321


  1. heidi says

    As one intimately aware of window collision issues, I must say that I was surprised at how promising window films are until you stick a dollar sign on them. Excuses from "you can't take pictures through the glass" to "it's just one or two birds every now and then" pop up all over the place. At least commercial buildings aren't full of birders. Kudos to Dr. Klem for his years of amazing effort, I hope this batch of window film meets expectations!

  2. BlackpollWarbler says

    this would be great for the company i work for in Redlands, California. A new building has just been erected, and there is a three story glass atrium that will no doubt be mistaken for a passage by birds.

    the building currently kills many birds, some of which i have watched hit windows, and others i have seen moments after their death.

    i will have to get in touch with the author and figure out the best approach to implementing this.

  3. heidi says

    Blackpoll – are you able to pick up the dead birds? If you can bring them to someone with permits (academic or otherwise), they'd make wonderful study skins.

  4. Beverly says

    Thanks for the link, it’s good to see we are beginning to see ‘choices’ in the window-film industry. Some time ago, I discovered FLAP, also linked on the page you reference, and found
    CollidEscape where I was able to get a sample of the film. This sample they offered me was about 18” x 18” (and free); the company was really nice to work with.

    Unfortunately, I found the stuff too dark, I would have felt like my brand new kitchen was suddenly in a cave! And yeah, no photography through the windows anymore. Still, I wanted to do something and discovered that regular, black nylon, bird netting works great. I’ve not had a dead bird since simply hanging the netting on the outside of my windows on tiny nails I put around the window frame. No fuss, no muss….and I swear I cannot see it at all and most of my photos taken out the window don’t either. Sweeeeetttt!

    Still, it is not as elegant as film would be; and I’d be happy to use this new film if I truly couldn’t see it from inside. I like the light!


  5. Cindy M. says

    We've long had all of our windows covered with birdscreens and a product such as this is SO very needed. I'm a nature photographer, but giving up being able to take images from inside my home was a *very *small price to pay to eliminate birdstrikes.

  6. heidi says

    Perry – most of the window films do not come with the designs already etched, cut or otherwise visible. That is done later, usually for human aesthetics. The gray film would look boring otherwise, but be just as effective (and less expensive, since it wouldn't need to be cut). You could really corner the birder market with the gray stuff, though =)

  7. ROHIT says

    I go through blog it's really good written. In fact, netting bird is an interesting topic to read. It has a wide knowledge about bird.. In fact, netting bird is an interesting destination i.e. covered by many websites. In fact
    We bought bird netting too, I had a couple of small tomatoes ruined by birdie beaks. Early on there were a couple of nice peppers and a few Juliet (grape) tomatoes – but the hail damaged many plants so might not get any Black Krim tomatoes. I’ve thrown old basil seed around and still had it come up. Don't give up yet;-]

  8. Christine Smith says

    I ordered mine from Apex Window films a week ago. Great product and easy to install. I got mine within a week. I am going to order more from them. You may get their toll free # from their website.

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