Many thanks for the comments.
I have checked the levels on the whites on the grebes and am fairly sure that they are ok. The redstart unfortunately would not play ball and I was always taking against the light which takes away the crispness of the image. If it was possible to get around the other side of the bird I am sure that the picture would have looked better, unfortuanately whenever I tried this the bird was long gone. The noise must have increased during the reduction for web use. I am happy with the 16 bit tiffs about 80-90mb, these are saved in two layers with one layer containing the high pass sharpening which I can reduce if required , there is a small amount of noise but well within what I would expect.
I will say that the canada is my favourite. This was taken lying down next to the pond on Dawlish Warren. I am always interested in the challenge of trying to get interesting images of the more common birds.