Thanks Brian - the negative for me is the OOF tail, spoils the shot, I should have used f8 ...... but it was hand held - not sure I can do anything about the blown white - certainly not in post - as when you have extreme darks and white blown whites seem inevitable?
the birds are also a little bluer in good light - but I am never sure these days that my screens are calibrated properly - the histogram helps but not always and they do look different on here when reduced to 250k and 800 x 800