Well, first, let me thank you all for the quick replies.
Second ... the bird has flown! I watched him for a while ... seriously, I thought he was going to lay an egg right there on my porch. His gyrations indicated he was clearly uncomfortable. Then ... he pooped ... big time ... and then flew off.
Enchilada reported that these birds often overindulge. There is a tree outside my porch which is simply over-loaded with berries right now. I'm guessing ... he ate too much ... he flew off and hit the window ... stunned himself .... dropped a load ... felt better ... and flew off.
Actually, somewhat entertaining! Thanks.
ctm