Hi Randy.
Here is a cropped screen dump taken from ZoomBrowser showing focus point for what it is worth.
Looks like the focus point was on the head/bill?
Could be a bit soft due to SS?
Good looking gull, and you got a beautiful pose outi of it. I love the far wing serving as a backdrop to the face. On my monitor I also see slight apparent softness on the eye and bill compared to the tail. The gull may have moved its head and caused some very subtle subject movement blur. I agree the hot spots on the neck could be toned down. BTW this is a magnificent BG, and judging from your "screen dump" you did a great job in bringing out the colours!
Great pose. Love the shadow of the right wing on the body of the gull but not covering the head. Couldn't be better IMO. First reaction when I saw the image before reading the comments: hmmm, the tail looks sharper than the head. But it's still very good IMO. Great background. JR
Obviously, you were right on with the focus, so I think your thought on shutter speed explains it, as Daniel said, just a bit of motion in the head at that critical time.