Why were Africa's giant animals such as elephants, giraffes, etc. not subject to extinction?

Question

extinction occured in American west 15,000 years ago

Answer 1

Because animals in that area existed in abundance, and there were no natural predators other than man, of which they had a natural fear. Men did not need to overhunt the megafauna in Africa as they did in North America. Moreover, since men had arrived only recently in America, megafauna on the American continent had no fear of them and were much easier to hunt as a result.

Another theory says that the megafauna of America were driven to extinction by climate change. Apparently the climate change during the Late Pleistocene that may have driven North American animals to extinction was not as severe in Africa.

A newer theory states that disease that spread through America but not Africa was to blame, but the offending microbes, if they indeed existed, have yet to be isolated or identified.