This was taken in 2015 with the predecessor to my current 100-400mm lens (ie the Mk1). That earlier lens could, if you got a good copy, produce acceptable images. My copy was no more than adequate.
I posted a first edit of this shot, using Canon's own processing software (which is awful) on 11 April 2016. I hope it's OK to have a second bite at the cherry with this new edit. Lightroom at least brings out some plumage detail here and there, where Canon didn't.
Thank you for your kind comments on my pictures, and good birding!
John