The Tswalu game reserve in the Southern Kalahari was created by Stephen Boler. He bought dozens of farms covering more than a thousand square kilometres to create a conservation reserve, introducing African wildlife back into their natural habitat, including lions, rare types of antelope, giraffes, buffalos, zebras and the black rhino (which successfully started breeding). To control the numbers and create a form or revenue to support the estate, there was a controversial hunting side called Takuni. After Stephen Boler's untimely death in 1998 on his way to Tswalu, he specified in his will that Nicky Oppenheimer should have first refusal on Tswalu, and the Oppenheimer family now owns and operates it.
Hunting was stopped by the Oppenheimers and some man-made structures, farm buildings and fences were removed. New land was added to extend and protect habitats and territories. Tswalu now holds the largest population of black rhino alongside other threatened species like the pangolin.