Bird Window Strikes

White Crowned Sparrow Zonotrichia leucophrys Courtesy US FWS Gary Kramer, Photographer
White Crowned Sparrow
Zonotrichia leucophrys
Courtesy US FWS
Gary Kramer, Photographer
THUNK! We have all been startled by the loud thunk of a bird hitting a window. In the United States window collisions kill an estimated 1 billion birds a year with 44% of bird window collisions occur at homes throughout the year. So, changes made around your home can help maintain our bird populations.

What happens to birds that crash into windows? About half of them die immediately from head injuries, broken necks and internal bleeding. The other half may recover. If you see a stunned bird, move it to a safe space away from cats or other predators, or place it in or under a box. Try not to handle the bird and don’t give the bird food or water. In 10-30 minutes the bird will likely be recovered enough to fly away.

Why do birds fly into windows? Birds don’t see glass as a solid object. Birds see the window as an opening that they can fly through or the see reflections of sky and trees in the window

The USU Bird Strike Project has been doing research on bird window collisions on the USU campus for the past several years. We have found that the vegetation planted outside the window has a greater influence on window strikes than window area. You can prevent window strikes by not planting fruit bearing trees and shrubs or setting up bird feeders 15-45 ‘in front of windows. Small birds can reach speeds of 30 mph within 15’. So, put those bird feeders right next to the window or more than 45’ away.Bird Window Strikes

If you have a window that experiences frequent collisions, treat the window to convince birds that they cannot fly through that space. Raptor stickers are popular but ineffective. Birds don’t see the stickers as predators. Small birds do not want to fly through spaces that are smaller than 2” high and 4” across. The width is the most important measurement. You need to convince the birds that the open spaces are no larger than 4” across.

There are a variety of effective ways to prevent bird window collisions; some of these are available commercially and others are do-it-yourself. I applied Feather Friendly Design vinyl to my windows and it has been very successful. The home installation materials come as strips of vinyl with small squares about ¼” in size every 4”. The strips are applied to the window with a credit card, then you peel away the strip, leaving the small squares. A DIY version is to dip your pinkie finger in paint and apply it every four inches on your window. Bird Tape is available in strips that can be applied every four inches to your window. Another option is to hang paracord at 4” intervals in front of the window. Window screens will prevent birds from hitting windows and shades can limit the amount of reflection that birds see. The American Bird Conservancy website has even more options for homeowners.
Bird populations are under a number of threats from urbanization, climate change and introduced predators. Some threats, like climate change, are difficult to tackle. But preventing bird collisions is a relatively easy step we can all take to preserve our bird populations.

I’m Kim Sullivan of the USU College of Science and I’m Wild about Utah.

Credits:

Photos: Courtesy US FWS, Gary Kramer, Photographer, https://digitalmedia.fws.gov/digital/collection/natdiglib/id/14064/rec/52
Audio: Courtesy and Copyright Kevin Colver https://wildstore.wildsanctuary.com/collections/special-collections/kevin-colver
Text: Kim Sullivan, Bridgerland Audubon Society
Additional Reading: Lyle Bingham & Hilary Shughart, Bridgerland Audubon Society

Additional Reading

Protecting Birds Against Window Strikes, Bridgerland Audubon, https://bridgerlandaudubon.org/window-strikes/

Grow Native For Birds, Bridgerland Audubon, https://bridgerlandaudubon.org/our-projects/grow-native-for-birds/

Strand, Holly, Bird vs. Window, Wild About Utah, November 10, 2010, https://wildaboututah.org/bird-vs-window-3/

Strand, Holly, Bird vs. Window, Wild About Utah, December 9, 2008, https://wildaboututah.org/bird-vs-window/

Rachel Sagers, Brinnlie Harward, Landon Keller and Haley Schmid with Dr. Kim Sullivan, Patterns of Bird Window Strikes on USU Campus and Physical Features that Increase Risk for Collision, Department of Biology, (Honors Program,) Utah State University, https://digitalcommons.usu.edu/cgi/viewcontent.cgi?article=1829&context=researchweek

How to Keep Birds From Hitting Windows, American Bird Conservancy, https://abcbirds.org/glass-collisions/stop-birds-hitting-windows/

Messmer, Terry, Cowell, Samuel, Dietrich, Dietrich, and Sullivan, Kimberly, Ask an Expert: Seven Tips to Keep Birds from Hitting Your Windows, Utah State University Extension, March 28, 2017, https://extension.usu.edu/news_sections/agriculture_and_natural_resources/bird-windows

Cowell, Samuel, Dietrich, Dietrich, Sullivan, Kimberly and Messmer, Terry, Reducing the Risk of Birds Colliding into Windows:
A Practical Guide for Homes and Businesses [NR/Wildlife/2017-01pr], Utah State University Extension, March 2017, https://digitalcommons.usu.edu/cgi/viewcontent.cgi?article=2682&context=extension_curall


Bird vs. Window

Contractor applies anti-bird strike film to a window
Photo Courtesy US FWS
Brett Billings Photographer

Hi, I’m Holly Strand.

Every fall, I cringe when I hear the soft thumps caused by feathery bodies slamming into the windows of our house. Etched designs into the window glass do not seem to deter these miniature kamikaze pilots.

The most intense period of window strikes occurs when birds are feasting on our chokecherries and crabapples. The birds get intoxicated from the naturally fermented fruit and their judgement flies out the window—or rather, into the window. Robins, waxwings and other fruit eaters are the most frequent flyers under the influence.

Ornithologists estimate that in the United States alone well over 100 million birds are killed each year by window collisions. Many accidents occur when birds see trees, sky, or clouds reflected on a glass but do not see the hard transparent window surface itself. Sometimes the birds are merely stunned and recover in a few moments. Often, however, window hits lead to severe internal injuries and death.

Ornithologist Pete Dunne found that feeders placed 13 feet away from a window corresponded with maximum deaths. However, a feeder place within a meter of window actually reduced the accident rate. Birds focus on the feeder as they fly toward the window. If they strike the glass leaving the feeder, they do so at very low speed.

You can redirect the accident prone birds by putting up awnings, beads, bamboo, or fabric strips. Stickers or silhouettes will help if they are spaced 2-4 in. apart across the entire window. At our house, taping some reflective ribbon to the window so that it flutters in the breeze has been very effective.

If you find a bird dazed from a window hit, place it in a dark container with a lid such as a shoebox, and leave it somewhere warm and quiet, out of reach of pets and other predators. If the weather is extremely cold, you may need to take it inside. Do not try to give it food and water, and resist handling it as much as possible. The darkness will calm the bird while it revives, which should occur within a few minutes, unless it is seriously injured. Release it outside as soon as it appears awake and alert.

For Wild About Utah, I’m Holly Strand.

Credits:

Photo Courtesy US FWS, Brett Billings Photographer, http://www.fws.gov/digitalmedia/cdm4/item_viewer.php?CISOROOT=/natdiglib&CISOPTR=9516
Text: Holly Strand

Sources & Additional Reading:

Dunne, Pete. 2003. Pete Dunne on Bird Watching: The How-to, Where-to, and When-to of Birding. HMCo Field Guides. http://www.amazon.com/Pete-Dunne-Watching-Where-When/dp/0395906865

Cornell Lab of Ornithology. Bird Notes from Sapsucker Woods. http://www.birds.cornell.edu/AllAboutBirds/notes/BirdNote10_Windows.pdf (Accessed Nov 30, 2008)

Leahy, Christopher. 1982. The Birdwatcher’s Companion. NY: Grammercy Books. http://www.amazon.com/Birdwatchers-Companion-North-American-Birdlife/dp/0691113882/ref=sr_1_1?ie=UTF8&s=books&qid=1228882143&sr=1-1

Wildlife Rehabilitation Center of Northern Utah, Ogden, UT http://www.wrcnu.org/

Bird vs. Window

The Cedar Waxwing is a fruit eating bird.
It can become intoxicated
eating the fermented fruit of
mountain ash, chokecherry
and other trees and bushes.
Courtesy Utah Division of Natural Resources

Hi, I’m Holly Strand from Stokes Nature Center in beautiful Logan Canyon.

While working at my desk this fall, I was unnerved by the frequency of soft thumps caused by feathery bodies slamming into the windows of our house. One day I counted 20 hits in a single hour . We have designs etched into the glass, but they didn’t seem to deter the feathery missiles from their kamikaze flight trajectories.

Intense periods of frequent window strikes coincided with feeding frenzies on chokecherry and then crabapple fruit in our yard. Birds get intoxicated from the berries and their judgement flies out the window (so to speak) impairing flight control. Robins, waxwings and other fruit eaters that feed on fermented berries from mountain ash, crab apple or other trees and bushes are the most frequent crash victims.

Of course drunkeness is not the only cause of bird- window confrontations. Sometimes birds attack windows. This spring, I was startled by an angry-looking robin trying to attack me through the glass. But I was not the object of his rage. He was simply a male defending his territory against his own reflected image.

But back to collisions. Most accidents occur when birds see trees, sky, or clouds reflected on a glass but do not see the hard transparent window surface itself. Ornithologists estimate that in the United States alone well over 100 million birds are killed each year by window collisions. Sometimes the birds are merely stunned and recover in a few moments. Often, however, window hits lead to severe internal injuries and death. Strikes are most frequent in winter because birds are attracted to feeders placed near windows.

Luckily, there are quite a few things you can do minimize collisions. First, check your feeder placement. Pete Dunne, an ornithologist, found that feeders placed 13 feet away from a window corresponded with the maximum deaths. However, a feeder place within a meter of window actually reduced the accident rate. Birds focus on the feeder as they fly toward the window. If they strike the glass leaving the feeder, they do so at very low speed.

You may want to cover windows with netting or screens which will function as a sideways trampoline if a bird should hit them. You can also redirect birds by putting up awnings, beads, bamboo, fabric strips. Stickers or silhouettes will help if they are spaced 2-4 in. apart across the entire window. A single, black hawk-shaped silhouette in the middle of a bit picture window does not prevent crashes.

If you find a bird dazed from a window hit, place it in a dark container with a lid such as a shoebox, and leave it somewhere warm and quiet, out of reach of pets and other predators. If the weather is extremely cold, you may need to take it inside. Do not try to give it food and water, and resist handling it as much as possible. The darkness will calm the bird while it revives, which should occur within a few minutes, unless it is seriously injured. Release it outside as soon as it appears awake and alert. If the bird doesn’t recover in a couple of hours, you could take it to a veterinarian or wildlife rehabilitator.

Thanks to the Rocky Mountain Power Foundation for supporting research and development of Wild About Utah topics.

For Wild About Utah and Stokes Nature Center, I’m Holly Strand.

Credits:

Photo Courtesy Utah Division of Natural Resources, http://dwrcdc.nr.utah.gov/rsgis2/Search/Display.asp?FlNm=bombcedr

Text: Stokes Nature Center: Holly Strand

Sources & Additional Reading

Dunne, Pete. 2003. Pete Dunne on Bird Watching: The How-to, Where-to, and When-to of Birding. HMCo Field Guides. http://www.amazon.com/Pete-Dunne-Watching-Where-When/dp/0395906865

Cornell Lab of Ornithology. Bird Notes from sapsucker woods. http://www.birds.cornell.edu/AllAboutBirds/notes/BirdNote10_Windows.pdf (Accessed Nov 30, 2008)

Leahy, Christopher. 1982. The Birdwatcher’s Companion. NY: Grammercy Books. http://www.amazon.com/Birdwatchers-Companion-North-American-Birdlife/dp/0691113882/ref=sr_1_1?ie=UTF8&s=books&qid=1228882143&sr=1-1

Wildlife Rehabilitation Center of Northern Utah, Ogden, UT http://www.wrcnu.org/