An endangered black rhino is seen in this file photo from the Etosha National Park in norhern Namibia last year. An American hunter has killed one of the animals, under a special permit he bought for $350,000. While the rhinoceros is referred to as black, its colors vary from shades of brown to gray. Barbara Scheer/DPA /LANDOV hide caption

itoggle caption Barbara Scheer/DPA /LANDOV