Boy oh boy ... these guys are shy and he almost climbed on your camera??? Nice and sharp here. Very nice head turn, maybe brighten up the face some, and try opening up the eyes if you can? I think it is slightly over saturated, but a very good job with the bird! The left upward branch stops abruptly, is close to the frame edge and looks broken off. Also, the lower left corner partial dead leaf can be safely evicted. Did you do some cloning around his beak/head and (our) right side wing? I do really like this.
This looks really dark and muddy on my monitor. You might try doing a levels or curves adjustment in PS and see if you can't bring up the detail of the feathers so the eye is more visible. It's a cool looking bird and you nailed the DOF!
Personally, I'd look at cloning out or blurring the BG (background) more - at the very least I'd clone out the sticks between the bird's legs.
I agree the image looks a little muddy, and the eye is not very distinct. I place the purple gallinule among the most difficult of birds to photograph well. The main problem is that their plumage is dark. This causes exposure problems, for me at least, and usually resulted in me lowering the shutter speed to get it right. In your case I think that the 1/125 sec shutter speed was too slow, and shows up mostly around the head, which most likely was moving more than the rest of the body. Great composition though.~onlybill