[bluejay]

Hello All, this is my first post here and my very first foray into the world of birding. We have a junco that has been tapping on our patio sliding glass door every day for over a week now. He goes to the same spot, behind a flower pot in the lower right corner of the glass and hits his beak against it for up to 30 seconds at a time. He usually flits around a bit and returns a few seconds later. Today we saw and heard him do this four times. He was also singing quite loudly the last time.
Although I left some seeds out for him, he didn't show any interest in them that I could see. Can anyone explain his behaviour?

[northvanrob]

Some Birds when they their reflection, they think it's a rival!

Then the bird attacks the reflection, usually it's a glass window!

The key is the Dark-eyed Junco singing loudly!

It's trying to outdo this rival, even though it's just it's reflection!

[bluejay]

Fascinating, thank you!
I just discovered a beautiful nest with eggs in a hanging flower pot two steps away. I've seen both male and female hanging around. One was sitting on the eggs and flew off when I pointed my phone camera at it. But they're back now.