The breed was developed as a hunting and protection dog.
Straight from the RR club of the US:
The settlers needed a dog that could flush a few partridge, pull down a wounded stag, or guard the farm from marauding animals and prowlers at night. They also needed a dog that could withstand the rigors of the African bush, hold up under drastic changes in temperature, from the heat of the day to nights below freezing, and go a full 24 hours or more without water if need be. They required a short-haired dog that would not be eaten alive by ticks. In addition, the settler needed a companion that would stay by him while he slept in the bush and that would be devoted to his wife and children.
"We become better trainers by refusing to swallow uncritically what is tossed to us as truth,
by developing our powers of empathy and observation,
and by searching for better ways to teach and educate the dogs we love."