Your visual markers must be large enough for birds to see. Dr. Sheppard recommends decals at least 1/4-inch wide and says that bigger is better because birds can see them from farther away.

Every year, hundreds of millions of birds die in the United States from flying into glass. New research shows how to prevent some of those deaths. By Catrin Einhorn A thump on the window, if you ...

Bird-friendly decals have been installed at the World Trade Center’s Liberty Park to prevent the animals from fatally smacking into the glass railings.

In some years, more than 30 killed or injured birds were found near the six-story building, Lund said. But exterior decals installed on three stories of windows has reversed that trend and saved ...