I have about 12 cardinals that are hitting my sliding door and my back door window on a daily basis. Can you tell me why they are doing this? I don’t want them to get hurt; they are beautiful birds. Plus it is annoying. How can I get them to stop? I have pictures of birds on the door and they still do this.
This is a pretty common occurrence, especially in spring when birds are establishing their territory. Here’s what’s happening. The cardinal sees his reflection in the glass, thinks it is a rival and attacks it. This doesn’t just happen with windows; I’ve seen birds go after car mirrors and shiny paint jobs. It is possible that the birds in your garden even think the pictures on your door are real birds too!
To stop the attacks you need to eliminate the reflection. Keep a light on so that the room behind the sliding door is not black, hang curtains or cover the window with netting. I’d also suggest removing or covering the bird pictures.