Thank you for that,Looks like a red ear slider with some shell damage, but I don't think it's rot.
Too little humidity? The African sun is unkind.Another shell shot. What causes that kind of damage?
A fall from the bird that likely dropped it?Another shell shot. What causes that kind of damage?
These guys are exotic and illegal in RSA. Despite that pet shops do sell them. I suppose some folk dump them in the dams and rivers when they get too big.It looks to me as if he's been dragged, scraping the carapace on hard ground. Or maybe a large carnivore's scraping teeth???
They are semi aquatic, spending most of the time in water, only coming out to lay eggs, wander to a new pond, look for a mate, or sit in the sun. Is there a pond or river, etc. nearby?