This is a genuine question!
I have been cellotaping paper over my windows for days now because a male chaffinch is attacking his reflection- even when the paper is over the reflection he has been trying to get behind! I have covered every pane in the garage windows and my kitchen windows, but to no avail.
His attack goes on for hours and the windows are covered in scratches and oily smudges. It is relentless.
I realise that "the sap is rising" out in birdland - but wondered if this was something more extreme? Are there any studies on a bird's mental state?
I can stand right next to him and he takes no notice of me!