Sadly birds collide with windows far too often. Audubon estimates that one billion are killed every year. These bird strikes are the second leading cause of death for birds. Outside domestic cats are the first.
These numbers include endangered species as well as backyard favorites like the hummingbird.
As we construct more buildings to meet the needs of humans we make the air space more perilous to birds. Making accommodations in our construction can help save the lives of many birds.
Why Do We Need Bird-Safe Glass?
Birds can see what is reflected in glass such as trees or the blue sky. They think those images are real and fly towards them.
So they may see the tree in your yard reflected in a window and think oh there’s a nice tree I’ll go land on its branches and then they crash into your window.
Birds see ultraviolet, so when the glass reflects ultraviolet light it tells the bird that the space is occupied rather than a clear place to fly. For humans, the window looks transparent.
How Many Birds Die From Hitting Glass?
Over one billion birds die every year from bird strikes. This has taken a toll on populations. Kenneth V. Rosenberg of Cornell Laboratory of Ornithology estimates that there has been a 30% population reduction since 1970.
This loss in bird populations has dramatic results in eco-systems. Birds function as pollinators and eat a variety of insects that prey on agricultural crops. They are an important component in ecological food webs.
Billions of birds are killed each year. Photo by Kenneth Herdy Audubondportland.org
What is Bird-Safe Glass?
We can make specialized glass that birds see as an obstacle but humans see as transparent. It’s a win-win answer.
There are different ways to make bird-safe glass but they all work to create a non-reflective pane so that birds can see it.
These break up the reflections on the glass and let the bird know that it’s a solid surface
In our modern techy age glass can be designed to not only be bird-safe but to have an interesting pattern for humans.
For example, the Minneapolis Central Library has bird-safe glass that was designed to look like a forest. When inside the library you can see out the windows normally.
Minneapolis Central Library - from the outside the windows look like birch trees in a forest and the pattern lets the birds know that they can not fly into it.
2x4 Rule
This has proven to be the most effective studies have shown that birds are afraid to fly through a space that is less than two inches high or 4 inches wide.
Markings or embedments in the glass are spaced 2x4 inches
Need more information on what to do if you find a baby bird? Check out our article!
Is Bird-safe Glass More Expensive?
Yes, bird-safe glass is an average of 5% higher in costs. Small price to pay for saving lives. Additionally, you don’t necessarily need to replace all windows in your home, just those that are a problem.
For instance, you may have a large picture window that faces a sunny backyard. You have observed that two or three times a week a bird flies into a window.
Replacing that window with bird-safe glass will stop the birds from hitting the glass. In many areas, it will also increase the eco-friendly value of your home.
How Can I Make My Windows Bird safe Without Buying New Windows?
1. Place your bird feeders close to your windows – within one and a half feet. This causes the birds to slow down and gives them a destination to land on. (Remember to wash feeders regularly)
2. You can purchase an inexpensive thin film from companies like Collid Escape
3. Use outside solar reduction curtains or shutters to block windows. Closing inside curtains may help but don’t necessarily stop reflections which is the main culprit.
4. Apply decals densely to the outside of the windows. If they are on the inside they may not be seen by the birds.
5. Markings should cover the entire pane of glass. Small dots in 2 inches by 2 inches pattern is highly effective according to Canada’s Fatal Light Awareness Program (FLAP).
6. Need a cheap quick and easy fix? Check out the video above on using soap to prevent bird strikes.
Dotted glass bird collision deterrent. Photo by Panek
Stand Up For Birds
Currently in Madison, WI a lawsuit has been filed by the Wisconsin Institute for Law and Libertyrepresenting five local developers to fight the City of Madison’s ordinance to use bird-safe glass on new construction. You can learn more about this on Madison Audubon’s website.
Take Away
Birds do a tremendous amount of good in the environment. Not to mention the joy they bring us with the songs, quarrels at the bird feeder, and beautiful colors. Help your local birds by planning for bird-safe windows.