You need a tad more focal length, unfortunately. I would also try and get the shutter speed up some - it may help the softness which could be a tad of motion blur even though you have VC. With my 300 f/4 + TC I usually have to have pretty high shutter speeds to get good, sharp photos of small birds. Of course, it has no VR and I am typically hand-holding it which doesn't help because it's a heavier lens. You're certainly improving - beautiful bird.