Rhinoceros conservation, South Africa. A black rhinoceros (Diceros bicornis) has had its horns removed by rangers at a private game reserve as a deterrent to poaching. The horn, which is made entirely from keratin protein, is removed with a chainsaw ten centimetres above the base. It is illegal to trade rhinoceros horns, however they fetch a very high price on the black market. They are used as ornaments and for some traditional medicines. Despite horn removal, rhinoceroses are still killed by poachers for the remaining horn stub or as an act of vengeance.