How to Stop Birds From Flying Into Windows: Effective Solutions

Bird collisions with windows are a pervasive and heartbreaking problem, resulting in the deaths of up to one billion birds annually in the U.S. alone. These transparent panes of glass, reflecting inviting landscapes or appearing as unobstructed flyways, pose a significant threat to our feathered friends. However, the good news is that you can take proactive steps to significantly reduce this danger around your home and contribute to bird conservation efforts.

An American Goldfinch, a frequent victim of window strikes, highlighting the severity of bird window collisions.

Christine Sheppard, the director of the Bird Collisions Program at the American Bird Conservancy (ABC), emphasizes that simple solutions can make a world of difference. Organizations like the ABC and the Fatal Light Awareness Program (FLAP) offer extensive resources and guidance on preventing these tragic incidents. Understanding why these collisions occur is the first step towards implementing effective prevention strategies.

Understanding Why Bird Window Strikes Happen

Birds collide with windows for a few key reasons, broadly categorized into daytime and nighttime collisions.

During the day, the primary culprit is reflected vegetation. Birds perceive the reflections of trees, bushes, and sky in windows as continuations of their natural habitat, leading them to fly directly towards the glass. They may also attempt to fly through windows, mistaking them for open passageways to indoor plants or vegetation visible on the other side.

Window imprint left by a Mourning Dove, illustrating the force and impact of bird window collisions.

At night, artificial lights are the major hazard, especially for nocturnal migrating birds, which include most songbirds. Lights from buildings and urban areas can disorient these birds, drawing them off their migratory paths, particularly in foggy or low-ceiling conditions. This disorientation can lead to birds milling around lighted areas and colliding with illuminated structures, including windows. Furthermore, birds attracted to urban lights may roost in these areas, only to face the daytime window reflection hazards the next day. Projects like BirdCast and FLAP are actively researching and addressing this issue of nighttime light pollution.

Another less common, but sometimes problematic, cause is territorial aggression. In spring, during breeding season, birds may see their reflection in a window and mistake it for a rival, leading them to attack the glass. While this behavior is more of a nuisance for homeowners, the solutions for general window strikes also effectively deter this territorial behavior.

Effective Strategies to Safeguard Your Windows for Birds

The first step in making your home bird-safe is to identify the most dangerous windows. These are typically large picture windows, corner windows, or any windows near bird feeders or with a clear view of vegetation or the sky reflected in them. To assess the danger, step outside your home and look at your windows from a bird’s perspective. If you see reflections of greenery or sky, or can see through to the other side, these windows pose a potential collision risk.

Reflected foliage in a window, a common cause of bird window collisions as birds perceive it as real habitat.

Contrary to older advice, the distance of bird feeders from windows is less critical than making the windows themselves bird-safe. If you have feeders near windows, prioritizing window treatments is key.

Here are several effective methods to treat existing windows and prevent bird strikes:

Treatments for Existing Windows

For smaller birds, markings should be spaced no more than 2 inches apart, while for larger birds, a spacing of 4 inches can be effective, especially with highly visible deterrents like Acopian BirdSavers. Crucially, all treatments must be applied to the exterior surface of the window.

• Tempera Paint or Soap: A cost-effective and durable solution is to use tempera paint or soap to create patterns on the outside of your windows. A 2×2 inch grid pattern is highly effective, or you can get creative with artwork.
• Decals, Stickers, and Tape: Apply decals, stickers, sun catchers, mylar strips, or even masking tape to the external window surface. Spacing is critical – ensure they are closely spaced, as a few scattered decals on a large window are ineffective. Hawk silhouettes alone are not effective deterrents. The key is pattern density, not the shape of the decal.
• Dot Patterns and Specialized Tape: Products like Feather Friendly offer pre-spaced dot patterns and tapes specifically designed for bird collision prevention, simplifying application and ensuring correct spacing.
• Acopian BirdSavers (Zen Curtains): These consist of paracords hung vertically and closely spaced in front of windows. Highly effective and aesthetically pleasing, they act as a visual barrier. They are used at the Cornell Lab of Ornithology headquarters. You can purchase pre-made units or create your own.
• Screens: Installing mosquito screens on the exterior of your windows, covering the entire glass surface, is a very effective and straightforward solution.
• Netting: Covering windows with netting, mounted at least 3 inches away from the glass and taut enough to deflect birds, is another robust method. Small mesh netting (around 5/8″ or 1.6 cm) prevents entanglement while ensuring birds bounce off safely. Netting can be mounted on frames for easy installation and removal.
• One-Way Transparent Film: Products like Collidescape are films applied to the exterior that allow people inside to see out but appear opaque to birds outside, effectively eliminating reflections. These films can also reduce incoming light and potentially lower cooling costs.

Strategies for New Homes and Remodeling

If you are building a new home or renovating, consider incorporating bird-safe designs from the outset:

• External Shutters: Install and use external shutters, closing them when rooms are unoccupied or when natural light isn’t needed. Shutters also offer excellent energy-saving benefits.
• External Sun Shades or Awnings: These block sunlight reflection and can be installed with remote controls for convenience.
• Window Screens on Entire Exterior: Opt for windows designed with screens covering the entire outer glass surface during new construction or window replacement.
• Interior Vertical Blinds: Utilize interior vertical blinds and keep slats partially closed to break up reflections.
• Minimize Visual Paths to Sky and Greenery: Avoid design layouts where windows create the illusion of a clear path to vegetation or the sky. For instance, windows directly opposite each other can create a “fly-through” effect. Interior solutions like closing doors or shades between rooms can mitigate this.

Lights Out Initiatives

For nighttime collisions, participating in “Lights Out” initiatives is crucial. Many cities are adopting these programs to reduce light pollution, especially during bird migration seasons. Turning off unnecessary lights in buildings, particularly in urban centers, and using downward-facing outdoor lighting significantly reduces the hazard to migrating birds. While these initiatives are vital, homeowners should still implement window treatments to address daytime collision risks.

How to Help a Bird That Has Struck a Window

Despite our best efforts, window strikes can still occur. If you find a bird that has collided with a window, immediate action can improve its chances of survival. Even if a bird appears to fly away after a strike, it may have sustained internal injuries.

Here’s how to assist a window collision victim:

1. Capture and Contain: Approach the bird gently from behind and use both hands to carefully scoop it up. Small birds are delicate, so hold them securely but gently, without squeezing.
2. Prepare a Container: Find a safe container, such as an unwaxed paper bag or a small cardboard box lined with tissue or paper towel to provide grip.
3. Provide a Safe Environment: Place the container in a dark, quiet, and warm location, away from children and pets.
4. Avoid Handling, Feeding, or Watering: Minimize stress by not handling, feeding, or watering the bird while it’s contained.
5. Contact a Wildlife Rehabilitator: Locate a licensed wildlife rehabilitator using online directories (like the Humane Society directory) and contact them for guidance. They can provide expert care and instructions.
6. Release (If Instructed): If the rehabilitator advises release, take the bird to a safe, wooded area away from buildings. Before releasing, observe its flight capability. If it doesn’t fly strongly, recapture it and seek further advice from the rehabilitator.

By understanding the causes of bird window collisions and implementing these preventative measures, you can make your home safer for birds and contribute to the well-being of local and migratory bird populations. Taking action today, no matter how small, can collectively make a significant positive impact.