Nice sharpness. Great capture on the texture of the feathers, possibly more impactfull out of context of the challenge. Seeing bird-butt made me double take a bit and pay attention.
LOL - funny angle. You've got good definition I think, but the white background and lighting wash out a lot of it IMHO. Difficult to appreciate the feathers variety of textures because of the glare. I also think you could move the subject to one side more to make it more interesting.
I love the light and the feathers...I'm just not crazy about the long and narrow crop...maybe if a little more on the right were cropped or even cropping out all the background and having the feather completely fill the frame? Still an interesting pic : }