Window Alert doesn't stop this bird from banging his head against the glass. In fact, he aims for the hologram. Later I found out that the alerts don't work for Cardinals. As a matter of fact, the Cardinal continued to bang his head on our window for nearly two years!! (ouch!!) Window Alert provided a full refund.
Vadersdadme is exactly right - Some highly territorial birds vigorously defend their territories and will even repeatedly attack their own reflection in windows. They do this because they perceive their reflection to be an intruder.
WindowAlert has a product specifically designed to address this called CardinalAlert - for Cardinals and Robins that repeatedly attack windows
windowalert 8 months ago
The decals are designed to stop accidental hits. This is a territorial bird attacking it's reflection in the window. The best method for this would be a mesh covering that blocks just enough of the reflection to prevent the bird from seeing the "intruder".
Vadersdadme 9 months ago
This isn't accidental, I have a female cardinal that attacks my window every year.
She even sets in the door handle and pecks at the glass. this is aggression and theres not much you can do.
mindnova 1 year ago