Rhinoceroses are an endangered species. Worldwide, the number of rhinos has decreased 90 percent in the past 50 years, to about 28,000. Since 1977, CITES has had a ban on international trade in rhino parts. The most valuable part of a rhino is its horn, which can be sold for prices that have risen to close to $14,000 per kilogram. Given the very high price, illegal poaching, in which rhinos are killed for their horns, has increased rapidly. Interestingly, if done properly, the horn of a rhino can be harvested without killing the rhino, and the horn will grow back.

What challenges does CITES face in attempting to prevent international trade from contributing to the extinction of the rhino?