Risk of Extinction and Categories of Endangerment: Perspectives from Long-lived Reptiles

Abstract. The IUCN Red List of Threatened Animals is an important conservation tool, but the accuracy of predictions about risks of global extinction within 10 years or three generations is difficult to test objectively. In this study, we
compare IUCN predictions with the results of attempts to derive realistic scenarios that could lead to the global
extinction of six species of long-lived reptiles. For three species, the IUCN predictions matched real events reasonably
well but still overestimated risks of global extinction. For the other species, the predictions did not match real
events. Reasons why disparities occur are discussed.