Researchers from Purdue University have discovered a possible solution for preventing birds from colliding with planes, in an effort to save millions of birds each year.

Despite using everything from fireworks to herding dogs to frighten birds away, attempts to prevent collisions don’t usually work after takeoff. Now, the solution from Purdue relies on red and blue LED lights to drive birds in the opposite direction of airplanes taking off at airports.

"The way we figure this out is to give the animal a choice," said Esteban Fernandez-Juricic, a professor of biological sciences at Purdue who led the study at the Ross Biological Reserve.

To demonstrate the effectiveness of their plan, researchers released a bird. Inches away, a possible flight path appears divided with one side lit up and the other side dark. The choice is a test of sorts to determine if the bird chooses between light and dark rather than between two different color lights. As such, if the bird flies in the direction away from the light, it suggests that that particular light might be a candidate for alerting birds to danger.

Using five different wavelengths of light, the test was repeated with birds consistently avoiding LED lights with peaks at 470 nanometers and 630 nanometers — those that appear blue and red to the human eye. Conversely, ultraviolet, green and white lights did not produce avoidance or attraction behaviors in the birds.

"We now have a behavioral assay we can use to test these attraction and avoidance behaviors in a systematic, standardized matter, and we can do it on various species," Fernandez-Juricic said. "We're able to test not just whether a light may be highly visible to a bird or not, but whether that light leads to the behaviors we're trying to generate."

The study appears in the journal PeerJ.