Unfortunately it is the only photo I have.
These are the owner's musings that give more information as to details:
"At one time I thought they were a depiction of grey partridge however their size, general appearance such as the hump backed appearance led me to believe they were guinea fowl. The problem with this supposition is that the birds in flight which appear to be the male of the species have little horns or tuffs on the head as opposed to one comb. My latest conjecture is that these are spur fowl depictions.
All very interesting to me as certainly not native to Germany and not likely a huntable population there. The gun is from 1928 and I might guess that the person for whom the gun was engraved hunted not only for mallards as depicted on the left plate but also for birds in Africa. I can well imagine that a well heeled German sportsman could well have hunted in South Africa as well as in his home country."BTW here is the right hand side:
