Nix is probably getting confused with Pretoria Zoo who has Ibex right next to their Urial sheep (formerly Barbary sheep). Joburg doesn't have ibex or had any that I know of. These enclosures and the one next door are both for Barbary sheep. The sheep rotate between the two enclosures. Now a days there are some marabou in the enclosure the sheep are not in. In the past the sheep rotated with kori bustard and some waterfowl (I don't remember what exact species unfortunately)