Charlie Sobcov's window decals are clear and transparent to humans, but not to birds. (Emily Chung/CBC)

Eighth grader Charlie Sobcov wants to stop birds from dying in collisions with windows, but he doesn't want to ruin anybody's view.

For his latest school science fair project he has invented painted, plastic decals that can be placed — discreetly — right in the middle of a window pane.

"This paint is a colour that birds can see but humans can't," he said Wednesday on CBC Radio's All in a Day. "It's like putting a big stop sign in the middle of the window."

The colour is ultraviolet, beyond the range of colours visible to humans. That means the "stop sign" lets birds know the window is solid, but is nearly invisible to humans.

Similar flying falcon-shaped decals already exist on the windows of some buildings, but unlike Sobcov's, they are black and can obstruct part of the window.

Sobcov, who studies at the Turnbull School, a private school in Ottawa, said he first fell in love with birds while on a trip with his parents to Costa Rica four years ago. He learned that bird populations were decreasing around the world, and that many scientists were blaming global warming.

He later read that about 500 million birds a year in Mexico, the U.S. and Canada were dying as a result of crashing into windows. Many deadly bird collision are with the windows of skyscrapers along their migratory paths.

Sobcov resolved to help save the lives of some of those birds.

Paint for cosmic bowling

He started researching bird vision and found out that a bird's eye view includes colours in the ultraviolet range.

After a search, he managed to find a company in Montreal that made fluorescent ultraviolet paint. The paint is used in the entertainment industry for things like "cosmic bowling," to make lanes glow. In normal indoor lighting, the paint is invisible, but when ultraviolet "black lights" shine on it, it emits light of a different colour — within the range that people can see.

So far, Sobcov has tested his flying falcon-shaped decals on the sunroom of a cottage neighbouring his family's cottage.

"Immediately the birds stopped flying into those windows," he said.

Sobcov has since posted a notice in the newspaper asking people to volunteer to help him test the decals, which can be easily peeled off and reused on a different window or a different part of the same window. He said he received responses from about 40 volunteers, including many who asked how they can buy the decals.

Sobcov said he needs to have his experiment completed by early February, but after that he may consider marketing his new invention.