By Susan Milius
Between a fifth and a generous third of the world’s mammal species now face the threat of extinction, according to the first comprehensive review since 1996.
![The largest review in a decade by the conservation monitoring organization IUCN reports that as much as a third of mammals face extinction. African elephants, at least, are classified now as nearly threatened rather than vulnerable.](https://i0.wp.com/www.sciencenews.org/wp-content/uploads/2008/10/8882.jpg?resize=300%2C218&ssl=1)
![](https://i0.wp.com/www.sciencenews.org/wp-content/uploads/2008/10/9049.jpg?resize=300%2C226&ssl=1)
Now 1,139 species rank in the most imperiled categories, the conservation monitoring organization IUCN reported October 6 at its World Conservation Congress in Barcelona, Spain.
Data from more than 1,700 experts went into this five-year review of the conservation status of all known wild mammals for the IUCN Red List of Threatened Species, the main global scorecard for extinction risk.