Great exposure, whites are perfect with nice detail. Complimentary bg color, excellent angle of head in frame.
If time had allowed, a smaller f/stop to increase dof would have been nice. Obviously you were set up for the sparrow!
I might try a version with the bird moved a sliver to the right. I can see the crop as is to work with the curve of the back. Could easily add a bit of canvas to the left to decenter the bird a bit.
Thanks everyone. The weird brown outline is on the original image but became more pronounce when I used a hue/saturation layer on the background. Great eye and thanks for pointing that out.