Glass is a major threat to birds as it’s invisible to them. Each year, millions of birds accidentally fly into glass windows, doors and facades, with many of these collisions being fatal. The estimated annual number of bird deaths in Canada due to glass strikes is 16-42 million! Birds are generally injured in trying to reach vegetation or the sky which is either located on the other side of the glass structure or reflected on its surface. This is not just an issue during times of migration, but remains a problem all year long. Bird-safe glass products do exist and can help the situation.
Why do birds fly into glass? Birds are deceived by:
- Reflection: Birds can’t see glass. Instead, they see what is reflected on the surface of the glass (sky, trees, plants, habitat). Even low reflecting glass can act like a mirror when it’s bright outside and dark inside. This is confusing to birds.
- Transmission: When there is a direct line of sight from one window to another (walkways, corners, bus stops, transparent wind/sound barriers), birds do not perceive the glass as a barrier. They attempt to fly through, causing the collision.
- Design: Building shape, location, and landscaping (especially the anticipated height of the tree canopy once mature) all have a considerable impact on the collision risk profile of a facility.
- Lighting: Birds use the night sky and ambient light levels to aid their navigation. Nighttime collisions are common as lighting inside buildings attracts birds. Artificial lights, particularly those that point upward, can lure and trap birds in their haze, where they may potentially die of exhaustion.
What is bird-safe glass?
Bird-safe glass has visual markers (a pattern or design) on the exterior surface that alerts birds to the presence of a solid barrier. A variety of approaches (fritting, etching, ultraviolet coating) create a pattern that breaks up the reflectivity of the glass and alerts birds to its presence. Having the markers on the outside surface of the glass gives birds a greater chance to identify the surface from all angles and in varied weather conditions. Testing has shown that the “2×4 rule” is most effective, meaning that markings are added across the pane, spaced two inches apart horizontally, and four inches apart vertically.
Treatment methods for bird-safe glass:
There are three different ways to treat glass that have been shown to be the most effective for bird-friendly applications. The decision of which to use is based on the project criteria for aesthetics, cost and bird safety.
- Fritted Glass: Fritted glass is a finely porous glass through which gas or liquid may pass. It is made by sintering together glass particles into a solid but porous body. This porous glass body can be called a frit. It’s bird-safe because it simultaneously incorporates the 2″ x 4″ rule and breaks up continuous reflections by wearing its pattern on the outermost glass surface.
- Etched Glass comes in a wide array of elegant patterns (horizontal and vertical stripes, closely or widely spaced dots, organic shapes) and is especially effective for birds because its patterns are etched directly into the surface of the glass, not applied as a coating, which can display glare in certain conditions.
- UV-Coated Glass works to deter bird collisions because birds can see UV light in the ultraviolet spectrum (ranging from 300-400 nanometers). The UV coating is visible to birds and not to humans. This gives a more aesthetically pleasing view of the overall building as well as for end-users looking out the windows.
Where can I buy bird-safe glass?
Many companies offer bird-safe glass, and the price is often just 5 percent higher than standard glass. Another option for limiting bird collisions is to construct buildings so that the glass is angled slightly downwards, and therefore won’t reflect the skyline in the same manner.
It’s possible to provide permanent coatings for glass that help birds to see glass barriers and avoid them. Some jurisdictions are implementing bird-friendly mandatory glass standards as part of their building code (such as Toronto and Vancouver). It might be time for you to consider bird-safe glass for your home and/or business.
Looking for bird-safe architectural glass? Call Calgary’s premier glass and mirror company, House of Mirrors & Glass. Visit our showroom. Our knowledgeable and efficient team provides excellent customer service with a focus on custom design. Call (403) 253-3777 or email us at info@houseofmirrors.com. Let us know what you’re looking to achieve and our experts will assist you!
