In this Wednesday June 6, 2012 photo Britain's Prince William, the Duke of Cambridge, feeds a 5-year-old black rhino called Zawadi as he visits Port Lympne Wild Animal Park in Port Lympne, southern England . The Duke of Cambridge has called people involved in the illegal trade of rhino horn "extremely ignorant, selfish and utterly wrong". Black rhinos are critically endangered in the wild because of the soaring price of rhino horn, which is worth more than gold due to demand in some countries. (AP Photo/Chris Jackson/Pool)