- Locate feeders and birdbaths about 20-30 feet from windows so birds have time to change direction or within 1-2 feet of them so they can't gather enough speed to cause significant injury.
- Window screens will reduce injury even if a bird flies into it. Use them where practical.
- Decals like Window Alert
- Mylar reflective strips hanging loose in front of the window will move in the breeze and alert birds flying too close to a window.
- Use a yellow highlighter to draw X's on the inside of a window. The fluorescent highlighter is visible to birds, because the fluorescent ink will simultaneously absorb UV and release visible light. However it works best in sunlight, and worst in low light or on overcast days. This last suggestion comes from an experiment conducted by David Sibley, author of the Sibley Guide to Birds. http://sibleyguides.blogspot.com/search/label/bird-window%20collisions
It is estimated that between 100 million and one billion birds are killed every year in the United States when they crash into glass windows. And even one billion deaths might be a conservative estimate, says ornithologist Daniel Klem Jr. of Muhlenberg College in Allentown, Pa.
Dr. Klem actually studied window collisions by conducting several experiments in which he hung clear panes of glass, mirrors, and picture windows adjacent to one another in a woody thicket facing an old field habitat. A strike was registered when a specimen was found beneath a window or a feather, body smudge or blood smear was found on the glass.
A copy of his study can be found on the following link: http://www.birdsandbuildings.org/docs/WB1989BirdWindowCollisions.pdf