Taking it as red: an introduction to the Theme Section on the IUCN Red List of Threatened Species

The IUCN Red List of Threatened Species (www.redlist.org) is a comprehensive list of relative extinction risk for species throughout the world, and it is commonly referenced in the scientific literature. Established in 1963, the IUCN Red List and its Criteria have been revised regularly to make them more scientific and objective. Nevertheless, the aim of the IUCN Red List to establish global standards across varied taxa has generated some controversy, particularly in terms of what is the most appropriate scale for both assessing the threat of extinction and setting conservation priorities for particular species. The papers included in this Theme Section of Endangered Species Research focus on the IUCN Red List and provide several recommendations for strengthening this conservation tool.