Surmised from New Scientist 12th August 2000...
...not many people know this, but before the year 1890, much of Sub-Saharan Africa
was open grassland, on which ancient civilisations
and some mighty empires
herded cattle and tilled the land.
The wide expanses of wild bush which we now protect as 'pristine environments' were only a fraction of their present size. In 1891, the rinderpest virus arrived from Europe, and killed around 95% of the livestock, starving 1/3 - 2/3 of the populations in East, West and South Africa.
Kingdoms fell, tribes vanished and the bush took over. The European powers walked in with no resistance, colonised, and believed that the situation they saw was the way it had always been. They set up the great national parks and forbade anyone, including the native inhabitants, from living there, when in fact they had been living there only 30 odd years before.