Saving Feathered Lives – How to Prevent Bird Collisions into Your Windows

Over 1 billion birds die yearly crashing into reflective glass windows. Imagine an entire species gone with one old building. The good news? With small actions, we can rewrite their fate.

Bird-window collisions are a major yet often overlooked threat to bird populations worldwide. Studies estimate that up to 1 billion birds die each year from striking residential and commercial buildings in the United States alone. Beyond the tragic loss of our feathered friends, these numbers also raise alarms about biodiversity and conservation. Something as simple as a window can have devastating ripple effects on ecosystems. From my own experience, I’ve witnessed the heartbreaking scene of a dazed cardinal struggling to regain flight after crashing into my living room window. Clearly, more awareness and action is needed on this issue.

• Apply decals or tempera paint to create visual patterns that alert birds to glass
• Install external screens or netting to create a soft barrier
• Close curtains or blinds to reduce reflections of sky and trees
• Strategically place outdoor feeders and plants to steer birds away
• Use UV-reflective glass films visible only to birds

The best ways to prevent bird window strikes

Create Patterns on Windows

Apply tempera paint, soap, or window decals to create patterns on the outside of windows. These patterns help birds recognize the presence of the glass and avoid collisions

Install External Screens or Netting

Placing external screens or a light net a few inches away from the window can help birds bounce off without getting injured

Close Blinds or Curtains

Keeping blinds or curtains closed, especially during the day, reduces the reflectiveness of the glass and helps prevent bird strikes

Move Interior Plants Away from Windows

Placing indoor plants away from windows can reduce the risk of bird collisions by minimizing the reflection of outdoor greenery

Place Bird Feeders Directly on Windows

By positioning bird feeders directly on windows, birds are less likely to build up enough speed to cause harm if they do collide with the glass

Understanding Bird Window Strikes

Birds don’t see clear or reflective glass in the same way humans do. They either fail to recognize the obstruction entirely, or they observe reflections of sky, clouds, and trees that give the illusion of a clear flight path. Transparent building materials are responsible for the majority of daytime bird collisions. Additionally, nocturnal migratory species are attracted to artificial night lighting, often with fatal results. Songbirds make up over half of window strike fatalities, followed by woodpeckers, hummingbirds, and owls. For species already threatened by climate change, habitat loss, and other factors, even minor additional mortality from window strikes can have population-wide impacts.

1. Annual Bird Mortality in North America: It is estimated that up to a billion birds die per year in North America as a result of striking windows, with both transparent and reflective glass panes causing fatalities. Migrating birds are particularly susceptible to window strikes, and certain avian taxa are more vulnerable than others (Sabo et al., 2016).
2. Mortality at Commercial Buildings: A study found that bird mortality from striking windows at commercial buildings averaged 55 birds/building/year at one location and 24 birds/building/year at another, with mortality higher during migration periods (Hager et al., 2008).
3. Global Impact: Windows contribute to the deaths of billions of birds worldwide. Although there are legal measures to reduce avian mortality from window strikes, they are often not enforced, and more innovative solutions are needed (Klem, 2014).
4. U.S. Bird-Building Collisions: In the U.S., it’s estimated that between 365 and 988 million birds are killed annually by building collisions, with about 56% of mortality at low-rises and 44% at residences. Certain species are disproportionately vulnerable to collisions (Loss et al., 2014).
5. Variation in Mortality and Scavenging Rates: Research shows that there is spatial variation in both mortality and scavenging rates within urban landscapes, influenced by factors like building location and window area (Bracey et al., 2016).

Prevention Strategies: External Solutions

Installing decals, screens, netting, or UV-reflective glass on the exterior surface of windows can effectively warn and deter birds. Decorative decal patterns should be no more than 2 x 4 inches apart across the entire glass surface to properly alert birds. For a transparent look, there are micro-dotted bird safety films that reflect UV light visible only to birds. External screens also provide safety but ensure good visibility from indoor spaces. Strategically placing bird feeders and baths at least 30 feet from house windows helps prevent attraction to dangerous areas as well. Furthermore, window strikes can be reduced by up to almost 90 percent by incorporating bird-friendly landscaping techniques that make glass less reflective.

Prevention Strategies: Internal Solutions

While external solutions are ideal, interior options can also reduce window collisions. Sun shades, curtains and blinds should be positioned so windows remain fully covered on the outside whenever possible. Apply window films in vertical stripes or irregular dot patterns spaced no more than 4 inches apart. At night, eliminate all unnecessary lighting, or install motion sensor lighting to turn on only when needed. Placing house plants directly on the interior window ledge can also deter birds from flying toward reflective glass.

Implementing one or more of these tips to make your windows bird-safe can go a long way in preventing needless bird deaths. With some creativity and commitment, we can co-exist peacefully with our avian neighbors. The lives of countless remarkable birds are depending on it.