I prefer the OP, just would open up the shadows a bit under the wing, tail and breast to get a hint of detail. The low-key B&W preserves the dark BG and gives a subtle but appealing contrast to the bird. Agree on the head tilt....................nice capture.
When I see birds I am familiar with converted to or shot in black and white, I always miss seeing the colors I know would be there. Of course that is assuming it is a colorful bird and not a mostly black and white bird.
But in this case, I have no idea what this bird should look like, so I don't worry about missing any colors and can appreciate what I see. I love the sharpness with all the great feather detail and, as has been mentioned, the head tilt. I agree that it might look a bit better, as Jay mentioned, with some selective lightening.