Scientific research has shown the following collision-deterrent strategies to be largely or entirely ineffective:
- Silhouettes of hawk (or any other shape), unless multiple silhouettes are applied in a dense pattern
- Single window decals, or any visual markers that are spaced too far apart
- UV decals or liquid, which are not visible to all bird species, and are least visible early in the morning, when most collisions occur
- Any visual markers or decals that are hard to see, or that fade or wash off
- Ribbons or string spaced too far apart
- Treatments applied to the inside of windows
- Noise deterrents
- Plastic owls
Some of these strategies may help somewhat, some of the time, but wouldn’t you rather choose a treatment that is proven to work?
Safe Wings volunteers have found that the presence of a hawk silhouette or a handful of decals on a window is a sure sign that we will find dead birds at that building.
For more information on methods that DO work, see our Best practices for preventing collisions.
