He is an expert, and worked those figures out himself as the man in charge, relying upon follow-up censuses to determine the effects and fine-tune targets. It is not rocket science. In contrast to the current hopscotching, Kruger management fully appreciated the role played by drought in weeding out old and diseased animals, however ghastly, and factored these into the next cull after the next census, obviously NOT culling again if numbers had been naturally reduced over the following few years.
He also says the suggested figure of 7500 hippo currently in Kruger is impossibly inaccurate.
