During the breeding season, birds such as American Robins, Northern Cardinals, Wild Turkeys or Sandhill Cranes can become territorial near their nests. When one of these birds sees its own reflection in a nearby window or the side of a vehicle, it may try to drive off the “intruder” by repeatedly attacking the window or vehicle. Of course, despite the bird’s best efforts, the “intruder” just won’t go away. Repeated attempts by the bird to get rid of the “intruder” stresses the bird and sometimes results in bill injuries or, in extreme cases, the bird’s death.
This territorial behavior is often seen in Illinois from late April through early August. After the nesting season is finished, the bird will stop attacking windows or vehicles. In the meantime, the best way to help these misguided birds is alter the reflective qualities of the window or vehicle. This can be done by placing decals on the outside of the window (you will need to use multiple decals). Another option is to temporarily cover the outside of the window with a non-reflective surface. Bug screens are effective, or you can use a sheet of plastic that prevents the bird from seeing its reflection. Clear, plastic painter’s drop cloths work well at blocking the reflection while still allowing light into a room. Plastic netting (¼ inch mesh) can also be suspended in front of the window to deter birds from hitting the glass. To protect vehicles, temporarily move them to a different location or cover them with a tarp.