The selective colour is a bit full-on for me - particularly the feet. You could consider either leaving some colour in the bg, or desaturating some of the fg. Nice dramatic bird posing.
an interesting new take on a bird shot. At first I was not so sure i liked it, but then studying it, it really is rather good. he really does pop out of the page at you, adn the background does blur away, very interesting. Tack sharp on his head adn feet nice colours well done
Personnally I'm not a fan of this BW/Color pictures, but that's my taste. Not so sure about his beak though, that looks like it is missing color where I would expect it.
I don't particularly care for the selective desat, and in this case I think it highlights the los of detail in the tips of the tailfeathers. The claw of the hawk being cut-off doesn't help matters either. Overall I will have to give this a 5.