Jan:
Very sharp on the head and eye, the breast feathers seem a bit soft, yet the foreground is very sharp. Perhaps just the nature of their feathers. I wish I could see a bit more of the legs/tail.
This could work as a vertical crop as well.
Might have been worth trying a shallower DOF to isolate the bird a bit from all the leaves. I might tone down the patch just above the birds head in the BG.
In a perfect world, I wish there was a bit more color separation between the birds colors and the background, just to help him standout, but nature has different priorities than us!:D
Great shot! I love the way the out of focus background makes the wonderfully sharp bird pop! I like the unusual composition and muted color scheme as well.