Territorial Scrub Jay?

Try putting window clings on the window glass to prevent a reflection from appearing. You could also try hanging a wind chime outside the windows. I don't think he'd fly into them.

I had these ridiculously stubborn swarming birds once wanting to nest on my front porch. I would not have had a problem with it except they were making their nest out of mud and making a huge mess right where all of my daycare parents have to walk at. I hung pie pans, a huge sheet over the whole opening of the porch, and sprayed air freshner out there, all to no avail.