Thanks for the comments. Are you (both) talking about a lightened halo just barely fringing the bird, or the darker smudge that appears behind it? If the latter, looking at it full size, I think that just a cloud density thing, or maybe a blurry bird thing, or both. I don't see any typical fringe lightening though (but I had to work to get a halo off of the rocks where they meet the sky, so I will definitely go back and look at the full size file when I'm back in the studio)
I was talking about the dark smudge. There's no sharpening halo as far as I see.