The Scope of the Problem
Birds are dying because they cannot see windows. Whether windows are clear, see-through, or reflective, birds hit these glass “barriers” with regular frequency. Bird mortality due to window collisions is high. Every year in the United States, 100 million to 1 billion bird-window collisions occur with the number of hits being more frequent during spring and fall migrations.
Bird-window collisions are the greatest human cause of bird mortality world-wide. It is more deadly to birds than power lines, pollution and pesticides, vehicles, cell towers and wind turbines. Only habitat loss and cats are more lethal.
Research has shown, it is the day-to-day collisions that occur year-round at residential and low-rise commercial buildings that account for most bird-window collisions.
Hundreds of x-rays have shown that birds do not break their necks when they collide with glass but that they suffer concussions and internal injuries. These injuries can take days to kill and victims fly away, to die elsewhere, out of sight and out of mind.
Solutions
Products to make your windows visible:
- Acopian BirdSavers
- American Bird Conservancy
- CollidEscape
- FeatherFriendly (residential application)
Architect & Industry Solutions
- AviProtek® Bird-friendly Glass
- GlasPro
- ORNILUX Bird Protection Glass
- Viracon Bird-Friendly Glass
- WindowAlert, Inc
Do it yourself
- Sharpie pens
- Soap
- Tempera paint
Contact Us
The Great Salt Lake Audubon Bird-wind Collision Working Group (BWCWG) is here to help you make your windows visible to birds. We are available for one-on-one consultations, group presentations, email conversations, and site visits. Contact us by sending an email to
Additional Resources
- Bird-Window Collision Deterrent Methods and Relative Costs
- Frequently asked Questions
- GlasPro-Bird Safe
- You can save birds from flying into windows
- Making your Windows Safer for Birds
- Selected Products Available Locally (in Utah), Linda Johnson
- How to stop the “Thuds” . . . DIY Acopian BirdSavers
- Saving Birds One Window at a Time – The Scope of the Problem
- Saving Birds One Window at a Time – Solutions
- Dark Skies and Bird-window Collision Local Surveys (3:39 minute MP4 video)
- Saving Birds One Window at a Time--1-hour PowerPoint presentation from GSLA BWCWG
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- Saving Birds One Window at a Time PowerPoint slides without narration from GSLA BWCWG
- Georgie Corkery speaks with Jeanne Le Ber about Bird-window Collisions; listen to the Long Hair Do Care podcast
Selected Academic Papers
- Brown, B. B., Hunter, L., & Santos, S. (2020). Bird-window collisions: different fall and winter risk and protective factors. PeerJ, 8, e9401.
- Brown, B. B., Kusakabe, E., Antonopoulos, A., Siddoway, S., & Thompson, L. (2019). Winter bird-window collisions: Mitigation success, risk factors, and implementation challenges. PeerJ, e7620. doi:DOI 7717/peerj.7620
- Klem, D. (2009). Preventing bird–window collisions. The Wilson Journal of Ornithology, 121(2), 314-321. doi:DOI 1676/08-118.1
- Klem, D., Farmer, C. J., Delacretaz, N., Gelb, Y., & Saenger, P. G. (2009). Architectural and landscape risk factors associated with bird-glass collisions in an urban environment. The Wilson Journal of Ornithology, 121(1), 126-134. doi:DOI 1676/08-068.1
- Kornreich, A, Partridge, D., Youngblood, M. & Parkins, K. Rehabilitation outcomes of bird-building collision victims in the Northeastern United States. PLOS, published: August 7, 2024. https://doi.org/10.1371/journal.pone.0306362
- Loss, Scott R., Tom Will, Sara S. Loss and Peter P. Marra, 2014. Bird–building collisions in the United States: Estimates of annual mortality and species vulnerability. Condor 116:8-23. DOI: 1650/CONDOR-13- 090.1
Personal Stories
Acopian BirdSaver
Acopian BirdSaver installed on picture window in Ogden this Spring 2024. You can see why the birds might think the window is habitat. Note the reflective nature of the window. The curtain is helping to reduce bird-window strikes.
Paul Vincent Bernard installed the Acopian Curtain on his 2nd floor windows.
Cory and Jessica Stokes installed the Acopian Curtain on their windows years ago. They caution that over time curtain will shrink in length due to getting wet. They recommend planning for this shrinkage by cutting the cords longer than is initially needed.
Jordan River Nature Center is Bird Friendly
The Tracy Aviary has a second campus along the Jordan River in South Salt Lake at 3300 South and 1100 West. The center’s building has lovely picture windows and a sliding glass door that looks south along the river. Unfortunately, these windows have experienced bird strikes. A nearby birdfeeder station and water feature offers visitors the opportunity to study the birds at close range from the center’s front porch. When feeders are located close to windows there can be an increased risk for bird-window collisions. What to do!?
Anne Terry, Director of the Jordan River Nature Center mitigated these windows to make them visible to birds and decrease the number of bird-window collisions. Anne used Feather Friendly® bird tape for this effort. Bird tape is applied on the outside surface of the windows creating an effective “frit” pattern. The tape is adhesive and wears well over 4+ years. The Feather Friendly® bird tape meets the standards set by the American Bird Conservancy for prevention of bird-window strikes. Products that bear the ABC Saves Birds tested logo have met the criteria established by ABC for making windows more visible to birds.
Stop by the Jordan River Nature Center to see this example of Feather Friendly bird tape in action.
Stephanie Weems explains how she mitigated her windows
Stephanie uses penned lines on her large picture windows to make her windows visible to birds. She has seen a significant reduction in bird-strikes since using this mitigation effort.
Supplies:
- Tape measure
- At least 2' level
- Ruler
- medium oil-based Sharpie pen
- Wet rag and fresh razorblade
- Dry rag
Preparation:
Since these lines will be painted on the outside of the window, it's easier to start with clean windows. These pens work better when it's at least 60 degrees outside.
Steps:
- Use the measuring tape to determine center of the window by measuring the horizontal width of the glass and dividing that measurement by 2.
- Make a small mark with the pen on the glass at the base of the window at the center point of the window.
- Using the ruler, starting at the center mark from the previous step, mark a point every 4 inches until the entire horizontal width of the window is marked every 4 inches.
- Position the level vertically at one of the marks from the previous step.
- After making sure the bubble in the level is centered, use the pen to draw the line from the mark as far as the level will allow.
- Reposition the level using that same line as a guide and continue extending the line until the line extends from the top to the bottom of the window vertically.
- Repeat previous step for each 4" mark on the window.
Mistakes are easy to erase and correct using a wet rag and a straight edge utility razor blade. To remove a section of line, wet the glass thoroughly and then use the razorblade at about a 35-degree angle to scrape the line off the glass. The glass must be wet or the razor blade can scratch. Then dry the surface thoroughly and re-pen the line.
Paint your windows with tempera
In July 2024, Suzanne Johnson had her granddaughters paint her back porch sliding glass door with tempera paint. The door is near her birdfeeders. Painting the outdoor side of the windows with washable, non-toxic tempera paint stops birds from hitting the windows. And it was really fun for the kids to use tempera paint and brushes to express their creativity. (used with permission)