G'day Matt,
Great to see another animal person

My feeble attempt at critique

(I'm trying) :
Shot #1: Looks as though it would have been a difficult shot for highlight exposure judging by the light coming through the tree on an angle... Dunno what time of day it was as I couldn't get the exif by saving the image locally (might be me stuffing up though). Enjoyed the composition very much.
Shot #2: That one I really like in an emotional way, very artistic framing.
Shot #3: DDE would help a lot to "even out" the dark feathers and highlights as I lose the feather detail... Have a play with DDE to see the differences...
Shot #4: Great catch in a focussed pose. Can't offer much on that one.
Dunno if this helps at all, I'm only a beginner and feel apprehensive about critique but I really enjoyed the shots as I'm an animal nut... Just got home from the Melbourne Zoo (again)... I'll post some stuff later for input...
Cheers,
Mudder