For fossils to thrive, certain favorable circumstances are required. First of all, of course, remnants of life have to be there. These then need to be washed over with water as soon as possible, so that the bones are covered with a layer of sediment.
The elephants were being slaughtered in masses. Some were even killed in the vicinity of big tourist hotels.
The land is not in the least bit fertile and yet the cattle herds grow larger and larger. A cow represents capital investment here.
The problem is that during the 1980s, a decade of heavy poaching, the elephants retreated to safer areas. And now people have moved into the corridors once used by the elephants.
Paleoanthropology is not a science that ends with the discovery of a bone. One has to have the original to work with. It is a life-long task.