When a bird collides with greenhouse glass it’s sad but preventable.

You may hear a sudden bump sound then see a dazed pigeon or starling flying away after flying into your greenhouse glass. When the light’s at just the right angle, greenhouse glass can appear to the bird to be a mirror.  This can lead to a dazed or even dead bird, and for your greenhouse, even broken glass.  Yet bird strikes can be prevented.

This post is based up on the work of Dr. Daniel Klem, Jr. Klem is an ornithologist and the author of Solid Air: Invisible Killer: Saving Billions of Birds from Windows.

“The latest scientific estimates suggest that annual bird kills at windows range from 365 million to 988 million per year in the U.S., 16 million to 42 million in Canada, and billions worldwide,” Klem writes. “Even the lowest U.S. estimate is equivalent to the avian death toll from 1,215 Exxon Valdez oil spill disasters.”

According to Klem, researchers have concluded that the overall number of bird-window collisions increases in areas with combinations of greenery and glass. “Increased casualties occur at buildings with nearby vegetation in the form of trees and shrubbery that attract birds to the danger zone near windows,” he writes.

Say your greenhouse is positioned in the middle of your back yard—and surrounded by trees, pollinator gardens and other greenery. With so much vegetation around to be reflected by so many windows, birds can get fooled by the reflections from the greenhouse glass.

What the Bird Sees

The main problem with most greenhouse glass windows is that birds just don’t see them. With a certain amount and angle of available light, a window might look completely transparent. As the light shifts, that same window can perfectly reflect the sky, trees and other natural elements.  A bird is not likely to see or sense that there the upcoming lite of glass is an obstacle.

Preventing Bird Strikes

Less effective options include silhouettes of hawks.  These may entertain your family, but studies have shown that they are not that effective. Another is keeping your greenhouse glass dirty. Dirty glass not only diminishes the light coming inside and provides a less attractive structure in your yard, but that is not effective either.

What has proven effective is either art patterns or some artwork on your greenhouse glass. A Sturdi-Built Greenhouse owner let us know that using Krink K-75 White Paint Marker (available on Amazon) and drawing fun art works on the glass is very effective.  The white paint does not wash off.  The white paint reflects some heat in the summer while adding some shading inside.  Say you painted images of flowers, plants, birds or even animals, so a silhouette of grandchild, in any case – have some fun!

If you are not that artsy, you can check out BirdSavers that sells finished window paracord products and also offers DIY instructions. And both CollidEscape and Feather Friendly sell specialty films or tapes intended to be applied to your windows’ exteriors.