Lovely pose, colours and sharpness, Andy. A slightly higher viewpoint would be nice but hard to achieve in practice at times. I am seeing and measuring a blue cast and there are some slightly hot whites - lifting the curve and masking it just to the bird brightens the mid-tones white leaving the highlights and BG as is. A little burning on the corners and brighter areas of perch and BG. Looking forward to more Auzzie kingfishers.
A bit tight for my taste and the shooting angle could be better but the sharpness is fantastic. The bird did a very good modeling job ;-)
I agree about the bluish cast and I think that composition can be improved with more room at the right. Superb details in the eye and I like the BG instead of the fact that is not very clean but allows us to see the bird habitat without being distracting.
This is why I came back here, not just compliments but real constructive critique of how I could have done better. I'm useless at noticing colour casts though !