Letter to the editor, the New York Times, February 4, 1992:

The widespread, persistent and increasing loss of wild birds (a high estimate of 976 million fatalities) from window collisions (not just winter feeders, but through the year, particularly during migration) contrasts sharply with the relatively meager losses from such catastrophes as oil spills, pesticides and collisions with vehicles. You did not go far enough in "Windows Near Bird Feeders Can Pose A Deadly Threat" (Science Times, December 31, 1991).

The Fish and Wildlife Service's Office of Migratory Bird Management introduced me to the expert on this subject, Dan Klem, when I was preparing a booklet on backyard bird problems. Dr. Klem, an Associate Professor at Muhlenberg College, may be the only ornithologist to consider "plate glass predation" worthy of study. The results of his nearly two decades of research have been published in journals, including an article on prevention techniques for Living Bird, the Cornell Laboratory of Ornithology's popular magazine, in 1985.

Dr. Klem's studies show that the scare techniques you mention, falcon silhouettes and owl decals, do not significantly reduce window deaths.

Homeowners can prevent a major cause of bird killing by requiring architects to use angled or nonreflective glass and by retrofitting windows with an external covering. Now that I know it's not just a few birds, I've chosen to cover my killer windows with bird netting.

—Heidi Hughes, Vice President, American Backyard Bird Society

†