White rhinoceros (Ceratotherium simum) horn removal, Umhlametsi Private Nature Reserve, South Africa. Horns are removed as an anti poaching measure. The rhinoceros is first tracked from the air and darted with a tranquiliser. The horn, which is made entirely from keratin protein, is removed with a chainsaw at ten centimetres above the base. Rhinoceros horns are used as ornaments and for some traditional medicines. Despite horn removal, rhinoceroses are still killed by poachers for the remaining horn stub or out of vengeance.