A flock of 398 birds hit a Galveston high-rise office building one evening in May, 2017. It was a devastating blow to learn such a large number of birds died, many migrating warblers, most whose populations are already threatened by habitat loss and climate change. Migrating songbirds fly at night, and a combination of factors, including a storm and lights left on in the American National Building, most likely disoriented the warblers.
As many as one billion birds are killed each year from hitting windows in homes and offices, according to the U.S. Fish and Wildlife Service. Sometimes it takes a significant event in the news as in Galveston to bring national attention to the risks that migratory birds are faced with each spring and fall from high-rise buildings, communication towers, and single family homes.
Although we most often hear about large numbers of birds hitting high-rise buildings, single-family homes can pose an even greater risk because of the sheer numbers overall of homes vs. office buildings.
We can reduce the risk of window strikes in our homes immediately by being aware of the types of risks (daytime, nighttime), easily modifying our windows and lights, and recognizing that spring migration (March 15—May 31) and fall migration (August 15—October 31) pose the greatest risks.
Fortunately there’s a lot of research on bird collisions, and easy and effective methods are recommended to reduce the risks. First, it’s important to understand the two types of window collision risks for birds—during the daytime and when flying at night.
In the daytime, birds fly into windows because they see reflections of landscape, vegetation, or sky. Identify which windows (home or office) are potentially most dangerous. Large picture windows, paired windows at right angles to each other, and any windows near birdfeeders pose greater risk.
To reduce risk from homes and office buildings—
•Apply bird tape in vertical strips on windows on the outside of the window spaced no more than 4 inches apart across the entire window. Tape allows you to get the correct spacing and is long-lasting. To research ABC BirdTape, http://www.collidescape.org/abc-birdtape .
•Acopian Bird Savers is an aesthetic alternative option to using bird tape. These are closely-spaced vertical ropes that are customized to fit and hang over your windows. To research Acopian Bird Savers, https://www.birdsavers.com.
•Standard window screens on the outside of windows (taut and at least 2-3 inches from window pane) are effective.
•Move indoor house plants so that they can’t be seen from the outside. Close indoor blinds and curtains to reduce the reflection of outdoor vegetation and sky in windows.
•Assess the views through all your windows to see what birds may see. Be aware that birds may see the illusion of a 'false pathway’ through your home when brightly-lit windows or sliding doors (in a more distant room or wall) are visible through windows, as a large picture window at the front of your home. Adjust blinds and curtains to reduce this risk.
Note: Decals, although easy to use, are only effective when placed very closely together.
At nighttime, nocturnal migratory birds (many songbirds, such as warblers, orioles, and tanagers) fly into city high-rise buildings, and suburban/rural homes and buildings, during spring and fall migration when they are lured off-course and disoriented by the lights.
To reduce risk from single family homes—
•Close all blinds and curtains at night.
•Minimize outdoor lighting, and install motion sensors on outdoor lights (which also saves electricity)
To reduce risk from office, high-rise, and industrial buildings—
•Have both outdoor and interior lights programmed to turn off/minimize at night.
•Communicate policies with maintenance, janitorial, and security staff to reduce evening lights when working (turning on interior lights in individual rooms only as needed, and keeping office blinds and curtains closed).
Communication towers are another big risk with nearly seven million North American birds dying by collisions with towers each year. Ninety-seven percent of migrants hitting towers are songbirds including threatened Golden warblers, Swainson warblers, and Yellow Rail (Communication Towers Are Death Traps for Threatened Bird Species, R. Nuwer; 1.14.2013, Smithsonian.com). Again, the highest risk is during spring and fall migration when nocturnal migrants are traveling between Canada and the United States. The birds become disoriented from the red ‘steady glow’ tower lights, but research shows that by replacing non-blinking red lights with flashing, blinking lights, bird mortality can be reduced by fifty to seventy percent.
Risks from rural and suburban buildings should not be underestimated. A recent online article in Anthropocene (An unappreciated threat to birds: window collisions in rural areas, B. Keim, 8.30.2017, Anthropocene) explains that isolated buildings in rural areas may be ‘especially powerful beacons [to migratory birds]’ and are often where a large concentration of migratory birds are found.
The FLAP Program (Fatal Lights Awareness Program) began in Toronto in 1993 and was the first program to address the dangers of urban lights for birds. In 1999, Chicago was the first U.S. city to begin a “Lights Out” program, and twenty-three U.S. cities now are on-board.
We can protect more birds, including many threatened species, with simple modifications to our homes’ windows and lights, talking with family, neighbors, coworkers, and advocating in our cities and communities. Call your state’s Audubon office for information on local Lights Out programs.