I think this is a Prothonotary Warbler, but some have said it not. Since the beak is not black
I think this is a Prothonotary Warbler, but some have said it not. Since the beak is not black
Sorry the picture was not there, but this link will show picture.
https://www.flickr.com/photos/60618221@N07/15305405879/
Nice photo of it! I don't see what else it could be but a Prothonotary Warbler. The pale bill could indicate a 1st year bird.
You are correct, it is a Prothonotary Warbler. I'm not sure about the "why" of the bill color, perhaps a seasonal thing but I've seen other images of birds like your one.