The cheetahs are part of the European Endangered SpeciesProgramme (EEP) at the zoo, which looks to increase the number of the critically endangered species.
Jean-Christophe Vie, deputy director of the International Union for Conservation of Nature speciesprogramme, disagrees with the review's conclusion that "species are more likely to be described than become extinct".
"This demonstrates greater sophistication, organization and finance behind the illegal movement of ever larger volumes of ivory from Africa to Asia, " said Susan Lieberman, director of the World Wildlife Fund's Global SpeciesProgramme.