The word "auction" usually makes us think of priceless art or fine wines. We rarely think of near-threatened species. However, people rich enough to spend in excess of $10 million can bid for 1,993 rhinos on Monday – International Save the Rhino Day. The South African multi-millionaire conservationist and entrepreneur John Hume is selling the beautiful beasts. He started a breeding project with 200 rhinoceros 30 years ago. He increased his stock by ten-fold. Mr Hume is also selling the 8,500-hectare ranch where the rhinos live.

Mr Hume's ranch is home to more than 10 per cent of the world's rhino population. Hume personally spent $150 million on increasing rhino numbers. He can no longer afford his animals. He has to pay vets' bills, security guards to keep poachers away, and helicopter patrols. He said: "I've used all my life savings…and I finally ran out of money. I'm hoping that there is a billionaire that would rather save the population of rhinos from extinction than own a super-yacht." He said: "Rhinos are underdogs. They stand the least chance of surviving poaching."