He's about as relentless as those guys, that's for sure. I'm laying in bed waiting this, listening to his tap tap tapping.

As I said to someone else, I don't want to use any that will scare them away in case there are eggs or babies.

I think most of those stickers are designed to let the birds know there's glass there so they don't fly into it. I don't think that's the issue here - I think he's seeing his reflection. I'm guessing I'd have to cover the glass with something less reflective to eliminate the issue.

That's what I said in the post body that we think is happening.

That was my concern too, but we're going on the third day (he's doing it as I write this) and he's relentless about it. If it was doing him any damagee, I think my glass door would be bloody by now.

Not as much as you think, says my partner who does urban bird work. I remember she said something about dotted or lined film...

https://birdstrikewindowfilm.com/

Oh yeah, and you can also get glass etched with the patterns. Apparently a lot of new municipal buildings do it to get bird strike certification.

I don't know if there are eggs or babies yet and don't want to do anything that will scare them away.

The chaffinch at my parent's place just treats those as rivals. Because he's an idiot.

If you read the post body, the nest is right above the door.