Saorsa and Dan, you are right, it is an Australasian Darter. (
http://birdlife.org.au/bird-profile/australasian-darter ) I didn't know that, I have always called them shags. I will try to amend the thread title so I don't mislead anyone else.
Dan, I agree the head is the most interesting part of the picture and I have cropped a bit closer and I think I like this better.
Paul, I tried a portrait crop but I didn't like it. The white breast / belly becomes too dominant for my taste. I think the tighter landscape preserves the S-curve in the head and neck that I like in this shot.
