Birds typically collide with a window during the daytime for one of two reasons:
Either the window is reflecting the surrounding habitat, and birds can’t tell the difference, or the window is transparent, and birds see through it to appealing objects on the other side.
Fortunately, a number of products are now on the market that will make the windows of your house less dangerous to birds without substantially reducing your ability to see through the glass from the inside. These include UV-reflecting glass, tapes, decals, and liquids and bird-protecting nettings and screens.
Below are links to manufacturers of antireflective vinyl or polyester films and decals that you can apply to the exterior of windows to make them visible to birds and minimize areas of clear or reflecting glass.
All Window Dressing, Etc.
“Glass art for windows,” these patterned films stick to any smooth surface, decrease glare and UV light, and reduce reflections and the illusion of clear passage. Take care to select a design that offers adequate coverage. Also available: vinyl decals that give windows, window corners, sidelights, and doors the appearance of etched glass. Available in a variety of natural, sporting, and artistic patterns.
Covers the entire exterior surface of a window, reducing its reflectivity and transparency substantially when viewed from the outside, while thousands of small perforations in the film allow light to pass through, permitting viewers inside to see out. Ten percent of the purchase goes to the nonprofit organization known as the Fatal Light Awareness Program (FLAP) to help fund research to reduce bird-window collisions.
A decorative window film that does double-duty as artwork. More than 150 patterns and shades are available, from stripes to bamboo to frosted. Easy to apply and remove.
Whispering Windows Anti-Collision Window Decals
White static clings you can place on the inside or outside of a window, where they contrast with dark reflections of trees and surrounding scenery. Choose from a variety of nature-themed designs. Easy to apply and reusable. Available at your favorite birding-supply store or garden center.
And don’t forget about good-old tempera paint. Widely available, long-lasting, and rainproof, it can be applied with a brush or sponge, either free-hand or with stencils. You can make your own, purchase them from your neighborhood art-supply store, or download them for free from www.spraypaintstencils.com or other websites.
Three tips for using decals and paint
1. Use multiple decals; create a pattern that covers the window uniformly. Elements arranged in columns should be four inches apart. Elements placed in rows should be two inches apart. This is often called the 2 x 4 Rule.
2. Elements should be at least one-eighth inch in width and should contrast as much as possible with the windowpane.
3. Patterns can be placed on the inside or outside of a window that is transparent. If it is reflective, the pattern must be applied to the outside.
Source: Bird-Window Collision Reduction: Tips and Techniques for Residents, Fatal Light Awareness Program
This post was excerpted from the article “Surefire Ways to Make Windows Friendly to Birds,” which appeared in the April 2013 issue of BirdWatching magazine. Read the full article and download a PDF.