Well, this is a new one! Just what do South African porcupines look like? I expect that they are different from the typical species we might find in NA?

I did a quick search and it seems that porcupines can be a problems over here, too. They respond very well to the predator scent repellents. Wolf, coyote, and fox urines are very popular repellents for lots of creatures and work very successfully.

Unless your SA porcies have no natural predators, I feel sure that this might be a better way to go rather than trapping.

Maybe in SA there is the equivalent to wolf, coyote and fox urines -- Cape hunting dog urine? Hyena urine? Lion urine? Jackal urine? Those probably would work to deter a SA "porker." I have seen the SA species. It shares a lot of similarities to our North American one, and perhaps share a common ancestor from back when Africa and South America were one landmass 40 million years ago.