FAQs

After colliding with glass, some birds may fly away or be only temporarily stunned.

Unfortunately in most of these cases, the birds do not survive off-scene of the collision. Flying into glass can cause internal hemorrhages, concussions, or damage to bird’s bills, wings, eyes, or skulls. While they may be able to fly temporarily, birds with even moderate injuries are much more vulnerable to predators and other environmental dangers.

These off-site deaths also likely go unaccounted for, making the real number of bird deaths by collision even higher than already estimated.

After colliding with glass, some birds may fly away or be only temporarily stunned or injured. Birds that may not look hurt could be suffering from internal injury.

If you find a stunned bird, follow these instructions and try to get the bird to a local wildlife rehabilitator as quickly as possible. If you find a stunned bird that is in a dangerous location (i.e. in the street, on an exposed sidewalk) and you do not have the ability to safely capture the bird (or there is no nearby wildlife rehabilitation center), you can try to gently re-locate the bird under nearby vegetation to better its chances of recovering and avoiding predation.

If possible to do without disturbing the bird, take photos and submit the collision to your local collision monitoring group and the Global Bird Collision Mapper.

Collisions often go unnoticed at both homes and commercial buildings for several reasons. First, many of the birds that hit windows do not die immediately and fly off without leaving a trace. Unfortunately, these birds usually die off-site by either succumbing to injuries or being more vulnerable to predators.

The bodies of birds that die on impact are often quickly disposed of by facilities managers that work early hours or by animal scavengers. Domestic cats, raccoons, birds of prey, gulls, and even squirrels, have been observed revisiting or waiting at windows where collisions frequently occur for an easy meal.

Birds may also fall where they cannot be accessed, whether on rooftops, through grates, in landscaping features, or into dense vegetation that makes them difficult to see.

If you have not seen collisions at your home or business, that does not mean they are not happening.

Anywhere where there is transparent or reflective glass near vegetation that birds are using, you can assume that collisions are occurring. To start learning where collisions are happening at your home and near you:

Listen for thud sounds: Birds make an unmistakable ‘thud’ sound when they fly into windows.

Look for marks in glass: When birds strike windows, oil on their feathers can leave marks and impressions on glass, sometimes in remarkably accurate silhouettes.

Search for Injured/Dead Birds: Regularly inspect the ground and vegetation under / around your windows to check for injured or deceased birds. Many birds are small and have well-camouflaged feathers which can make them difficult to see on the ground unless you are closely looking.

Utilize GPS Data: Check GPS data sites like Flap Mapper, dBird, and Global Bird Collision Mapper to check for reported collisions near you.

No, this is a common misconception. In 2014, Smithsonian researchers estimated that homes and other buildings one to three stories tall accounted for 44 percent of all bird fatalities and high-rise buildings. Skyscrapers can be higher in number of collisions per individual building, but they are limited in numbers, whereas there are millions of residential and < 3 story buildings.

Always treat the external side of glass. If applied on the inside, it may be hidden by reflections on the outside.

If you are treating a standalone glass structure like a railing that may be threatening from both sides, determine if the glass is reflective or just transparent. If it is reflective at all during the day, you will need to treat both sides to prevent collisions.

If the glass you want to treat is very difficult to reach, consider hiring a professional to install your treatment for you. If the only possible action is to treat the inside of the glass, do this test first:

Tape paper or sticky notes to the inside of the glass. Starting in the early morning, look at the treated glass from the outside every 2-3 hours. If you can see your treatment clearly through the glass for most of the day, birds might be able to as well, and you can apply an internal treatment.

Yes! There are many options to help protect birds without permanently altering windows, including tempera paint, paint markers, and paracord. In addition to making your windows visible to birds, you can also turn lights out at your residence during both spring migration (March-June) and fall migration (August-November).

Any glass that is transparent or reflective poses a threat to birds. Here are a few examples of glass that would not pose a threat to birds:

1. Glass covered by external screens or shading systems, including louvers.
2. Stained glass
3. Layered or channeled glass including glass block, channel glass, laminated safety glass, and spandrel glass.
4. Antique glass, also known as “wavy glass.” The distortions and imperfections in this traditionally handblown glass may reduce reflections and make it more visible to birds.
5. Dirty glass. Passive problem-solvers, rejoice! Dirty windows can be more visible to birds.

Not at all! Buildings can be made bird-friendly without sacrificing natural light or views. The visual interruption of the small patterns on bird-friendly films and glass can be extremely minimal, as shown in this helpful glass visualizer developed by Guardian Glass.

No, in fact, we believe the guidelines for bird-friendly design practices will push the limits of creative design as we know it by generating new innovations, incorporating different perspectives, and thinking “outside the box”!

Not necessarily. Bird-friendly design practices are simply another factor when selecting a design intention for a facade and outlining a construction budget.

Although there can be a slight premium for acid-etch or ceramic-frit patterned glass, especially for a custom pattern, this cost is often offset by the gains the glass adds to the overall thermal performance of the building. The lifespan cost of products should be considered also; bird-friendly glass may be more expensive upfront but adhesive solutions have a shorter lifespan (although still up to 10-15 years!) and therefore will require maintenance costs.

It is ideal for all glass in a building to be made visible to birds, but certain architectural aspects are and glass placements on a building are known to pose a higher risk of collision and can be prioritized for bird-friendly treatment. A window replacement or facade renovation project can also be an opportune moment to incorporate bird-friendly features. 

In general, protecting birds is a win for any company’s sustainability efforts and can be publicized as such in any press about the new construction.

Not only can bird-friendly design contribute to a building’s architectural statement, but it can also support daylighting strategies for a building. Many bird-friendly glass products can be used to increase a building’s energy efficiency by reducing solar heat gain and glare, positively impacting heating and cooling loads.