Lovely BG and iridescence. Soft light really works well - I like the way it reveals the beak detail. Wondering if a small puff of fill flash would have been an option.
Really nice image of a Grackle! The BG is superb as well. The H.A.P. might be on this one a bit and it looks like you have a white "glow" around the bird.
Like the iridescence and the sharpness of the bird against the nice soft BG. The head angle could be a little better, and I see a halo around the bird.