As usual I am relying on the guide for identification, even with the books I am at a loss to really positively identify anything out of the ordinary, and for me at least this is out of the ordinary.
Taken on Rhino Island, Matusadona Mational Park, Zimbabwe 19th September 2019.
EOS id MkIV
500mm F4 IS hand-held from open game viewing vehicle
Ken, I feel you are correct in your ID. Had a look in my book, and it was a toss up between a Gabar, or a dark chanting goshawk. I like the lookback pose, together with the two tone BG. I would maybe also just darken the BG a tad.
Beautiful bird, well-captured. The sharpness is excellent, but I agree with Stuart about darkening the BG. In fact, I think the entire image can go darker.
The perch is a bit busy. Not much you can do about where they land, but you might at least consider cloning out the two vertical twigs to the right of the main perch.